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S Burdach

Publications and source records attributed to S Burdach.

At least 73 records · Page 4Linked to original sources
PubMed1995

Interleukin-10 directly inhibits the interleukin-6 production in T-cells.

IL-6 is a potent regulator of T-cell activation, proliferation and differentiation. Since IL-10 inhibits cytokine production by T cells, the effect of IL-10 on IL-6 production by T cells was investigated. IL-6 production by purified monocytes or T cells was detected from cell-free culture supernatants by ELISA after stimulation of the cells with LPS or an anti-CD3 monoclonal antibody for 3 days. Although the main source of IL-6 are LPS activated monocytes (29.6 +/- 10 ng/ml), T cells secreted sufficiently high levels of IL-6 (790 +/- 200 pg/ml) to stimulate the high affinity IL-6 receptor. IL-10 decreased anti-CD3 induced IL-6 mRNA expression by up to 80%. In addition, IL-10 significantly inhibited IL-6 release from T-cells. Highly purified, anti-CD3 activated T-cells secreted 600 +/- 150 pg/ml IL-6 compared to 21 +/- 2 pg/ml IL-6 following addition of IL-10 (10 ng/ml; P < 0.001). FACS analysis revealed a monocyte contamination of the T-cell preparations of less than 0.5%. In addition, no IL-1 production was detectable. Thus, in our experiments the effect of IL-10 on IL-6 production was independent of the presence of monocytes. Finally, inhibition of IL-6 production was not reversed by IL-2 (100 U/ml). In conclusion, IL-10 suppressed the synthesis of IL-6 by T-cells via a monocyte- and IL-2-independent mechanism. These results may help to understand the complex regulation of T-cell mediated cytokine production by IL-10.

Cells, Cultured↗
PubMed1995

Mixed haematopoietic colony formation via immature blast cell clusters on foetal mesenchymal cell layers distinguishes stem cells from peripheral blood, cord blood, bone marrow and blood stem cells mobilized by granulocyte-macrophage colony-stimulating factor.

Multilineage colony formation was evaluated from healthy donors' bone marrow (BM), peripheral blood (PB) and cord blood (CB) and compared with blood stem cell (BSC) harvests of sarcoma patients mobilized with granulocyte-macrophage colony-stimulating factor (GM-CSF). The test was a modified CFU-blast assay performed with and without an irradiated foetal mesenchymal cell layer (HFFF). These non-transformed mesenchymal cells served as a good source of haematopoietically active stroma cells in that cytokine expression patterns (interleukin (IL)-6, granulocyte (G)-CSF, GM-CSF) and adhesion molecules on HFFF cells were qualitatively identical to BM-derived fibroblasts, but the expression density of adhesion receptors was significantly higher. This HFFF layer stimulated blood stem cells of GM-CSF-treated patients significantly more than a cocktail of exogenous growth factors with IL-1, IL-6, and stem cell factor (SCF). The reverse was true for multilineage colonies from healthy donors' PB, BM, and CB. According to these results, stem cells of GM-CSF-treated patients are functionally distinct due to their dependence on stroma-derived factors and/or matrix-adhesion interactions and can be reproducibly evaluated on these mesenchymal cells.

Blood Cells↗
PubMed1995

Bone marrow fibroblasts from children with aplastic anemia exhibit reduced interleukin-6 production in response to cytokines and viral challenge.

Defects of the bone marrow microenvironment have been implicated in the pathogenesis of aplastic anemia (AA). We examined granulocyte/macrophage colony-stimulating factor (GM-CSF) and IL-6 production in bone marrow fibroblasts from five children with AA in response to cytokines and viral challenge with cytomegalovirus (CMV). Cytokine-stimulated IL-6 production in patients' fibroblasts was significantly reduced, whereas GM-CSF production was found to be comparable to normal controls. Also, CMV-mediated stimulation of IL-6 production was significantly lower in bone marrow fibroblasts from patients with AA. During the late phase of CMV-infection, IL-6 production was suppressed in CMV-infected fibroblasts from patients with AA with 90% inhibition of IL-6 protein production and marked reduction in IL-6 mRNA accumulation. Defective IL-6 production in bone marrow fibroblasts might contribute to hematopoietic suppression in some patients with AA.

Adolescent↗
PubMed1995

Treatment of acute renal failure with urodilatin after unrelated bone marrow transplantation in an 18-month-old boy.

Acute renal failure was imminent in an 18-month-old male infant 20 days after unrelated BMT. The infant was treated with urodilatin (URO), a natriuretic vasorelaxant peptide. Diuresis increased 2 h after the commencement of URO infusion and the furosemide infusion was reduced from 5 mg/h to 2.5 mg/h. After seven days of URO treatment diuresis was normal, the serum creatinine level had decreased, and furosemide was reduced from 12 mg/kg bw/d to 1.8 mg/kg bw/d. No side effects were observed either during or following URO therapy. We consider URO to be a promising drug for the treatment, without any apparent side effects, of imminent or manifest acute renal failure in infants following BMT.

Acute Kidney Injury↗
PubMed1995

Correlation of low histidine rich glycoprotein plasma levels with the occurrence of acute graft-versus-host disease after allogeneic bone marrow transplantation.

Histidine-rich glycoprotein (HRGP) is a potent inhibitor of T cell activation and production of cytokines such as (gamma-IFN). gamma-IFN released by activated T cells is increased during a short-term period at the onset of GvHD after allogeneic bone marrow transplantation. Therefore we investigated HRGP plasma levels in patients after BMT. Blood was collected from 20 children before and up to 6 weeks after BMT. In patients without GvHD, HRGP plasma levels decreased during the first week after BMT to 237 +/- 60 micrograms/ml, compared with 302 +/- 104 micrograms/ml before transplantation. However, no significant changes in mean HRGP plasma levels were observed during the following 5 weeks of the posttransplantation period. Acute GvHD occurred in 10 of 20 patients between the second and third week after BMT. HRGP levels (mean +/- SEM) in patients with GvHD dropped during the first week to 158 +/- 32 micrograms/ml, compared with pretransplant levels of 240 +/- 48 micrograms/ml). In contrast to results in patients without GvHD, a second and significant decrease was obtained between the second and third week after BMT in patients with GvHD (161 +/- 35 micrograms/ml vs 84 +/- 13 micrograms/ml; p < 0.01). In the third week after BMT, HRGP levels were significantly lower in patients with GvHD as compared with patients without GvHD (166 +/- 29 micrograms/ml; p < 0.01). The decrease in HRGP in the second and third posttransplantation week was not a result of steroid treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1995

Impact of megatherapy in children with high-risk Ewing's tumours in complete remission: a report from the EBMT Solid Tumour Registry.

The European BMT Solid Tumour Registry (EBMT-STR) received reports from 21 European transplant centers on 63 patients (50 Ewing's sarcomas and 13 peripheral neuroectodermal tumours) in first (n = 32) or second CR (n = 31) consolidated with megatherapy and BM and/or PSC rescue between December 1982 and November 1992. There were 31 males and 32 females with a median age of 12 years (range 1-30 years) at megatherapy. The median follow-up time since megatherapy is 4 years (range 1 month to 10 years), Thirty-two patients with metastatic disease at diagnosis (22 had metastases to the bone and/or bone marrow) and consolidated in CR1 reached an actuarial event-free survival (EFS) of 21% at 5 years. Thirty one patients in CR2 achieved an actuarial EFS of 32% at 5 years. Favourable outcome was limited to relapse patients with localised disease at initial diagnosis. Distant relapse had a more favourable prognosis than local failure. Analysis of the different megatherapy strategies could not identify a significantly superior approach, nor is there convincing evidence in favour of double graft procedures. From the above results it appears that consolidation treatment by megatherapy contributes to improved EFS rates in high-risk patients compared with historical experience. Major questions for the future to be addressed prior to randomised studies include agreement on the definition of high-risk patients and the most efficient megatherapy procedure.

Adolescent↗
PubMed1995

IL-2 inhibits proliferation of K562 cells and reduces accumulation of bcr/abl mRNA and oncoprotein.

Cell lines of myeloid origin have been shown to express interleukin-2 receptors (IL-2R). Here, we demonstrate the expression of IL-2R alpha and IL-R beta on the CML blast cell line K562 by FACS analysis and cross-linking assay. Furthermore, we examined the effect of IL-2 on leukemic progenitor growth, employing K562 as a model. Clonogenic growth was assessed after 3 days of culture by colony formation in a serum-free, semi-solid assay system. IL-2 was found to exhibit a dose-dependent suppressive effect on K562 clonogenicity with 48% inhibition of colony formation at 250 U IL-2 and 60% inhibition at 1000 U IL-2. Philadelphia chromosome (Ph)-positive K562 cells possess multiple copies of the bcr/abl fusion gene whose transcript and protein product (p210) is thought to confer growth advantage to CML cells. We therefore investigated IL-2-dependent modulation of bcr/abl mRNA accumulation and p210 protein levels in K562 cells. After 4 h of culture in the presence of IL-2, a 3-15-fold reduction of bcr/abl mRNA accumulation was demonstrated by competitive reverse PCR. Reduction of bcr/abl fusion protein levels was demonstrated at 24 h of IL-2-supplemented cell culture, employing p210 recognizing monoclonal antibodies (mAbs) in FACS analysis. Levels of proliferation marker Ki67 were only marginally affected. We conclude: (1) K562 cells express both IL-2R alpha and IL-R beta; (2) IL-2 inhibits clonogenic growth of K562 in a dose-dependent manner; and (3) IL-2-mediated inhibition of K562 proliferation is preceded by a reduction of bcr/abl mRNA accumulation and p210 protein levels.

Base Sequence↗
PubMed1995

Time course of interferon-gamma production deficiency after autologous and allogeneic stem cell transplantation for malignancies.

While success of autologous bone marrow transplantation (BMT) for malignancies largely depends on the cytotoxicity of the ablative regimen, achievement of relapse-free survival after allogeneic BMT is thought to be enhanced by immunologic effects. We therefore investigated in vivo and in vitro production of interferon-gamma (IFN-gamma), soluble interleukin-2 (IL-2) receptor alpha-chain (sCD25), tumor necrosis factor-alpha (TNF-alpha), and granulocyte-macrophage colony-stimulating factor (GM-CSF) in patients before and during various time periods up to 2 years after autologous and allogeneic BMT. Cytokine levels were assessed in patient plasma and in supernatants of patient-derived peripheral blood mononuclear cells (PBMNC) cultured for 3 days in the presence of T cell-specific stimulation via CD3 plus IL-2. Our studies show that IFN-gamma plasma levels are decreased in autologous graft recipients before and during the first 30 days posttransplant. In allogeneic graft recipients, IFN-gamma plasma levels are also decreased during the first 30 days posttransplant, but otherwise are comparable to normal control (NC) values. In vitro stimulated PBMNC from autologous graft recipients also exhibit an IFN-gamma production defect before and during the first 30 days posttransplant. In contrast, before and up to 30 days after allogeneic BMT, stimulated IFN-gamma production is comparable to NC values but then gradually decreases, reaching its trough levels at between 61 and 180 days post-BMT. The IFN-gamma production defects in both patient groups seem to be specific, as sCD25, TNF-alpha, and GM-CSF production in stimulated PBMNC is normal or even enhanced at any time after autologous or allogeneic BMT. Deficient IFN-gamma production in patient-derived PBMNC does not correlate with variation in monocyte, T cell, or natural killer (NK) cell numbers during the posttransplantation course.

Adolescent↗
PubMed1994

A controlled trial of recombinant human erythropoietin after bone marrow transplantation.

Recombinant human erythropoietin (rHuEPO) stimulates erythropoietic bone marrow cells and increases erythrocyte production. This prospective study was designed to evaluate the effects of rHuEPO on regeneration of erythropoiesis after allogeneic or autologous bone marrow transplantation (BMT). Seventeen centers participated in this randomized, double-blind, placebo-controlled multicenter trial. The randomization was performed centrally for each center and stratified according to allogeneic or autologous BMT and major ABO-blood group incompatibility. One hundred and six patients received rHuEPO after allogeneic BMT and 109 patients received placebo. After autologous BMT, 57 patients were treated with rHuEPO and 57 with placebo. Patients received either 150 IU/kg/day C127 mouse-cell-derived rHuEPO or placebo as continuous intravenous infusion. Therapy started after bone marrow infusion and lasted until independence from erythrocyte transfusions for 7 consecutive days with stable hemoglobin levels > or = 9 g/100 mL or until day 41. After allogeneic BMT, the reticulocyte counts were significantly higher with rHuEPO from day 21 to day 42 after BMT. The median time (95% confidence intervals) to erythrocyte transfusion independence was 19 days (range, 16.3 to 21.6) with rHuEPO and 27 days (range, 22.3 to > 42) with placebo (P < .003). The mean (+/- SD) numbers of erythrocyte transfusions until day 20 after BMT were 6.6 +/- 4.8 with rHuEPO and 6.0 +/- 3.8 with placebo. However, from day 21 to day 41, the rHuEPO-treated patients received 1.4 +/- 2.5 (median, 0) transfusions and the control group received 2.7 +/- 4.0 (median, 2) transfusions (P = .004). In the follow-up period from day 42 up to day 100, 2.4 +/- 5.6 transfusions were required with rHuEPO and 4.5 +/- 9.6 were required with placebo (P = .075). A multivariate analysis (ANOVA) showed that acute graft-versus-host disease (GVHD), major ABO-blood group incompatibility, age greater than 35 years, and hemorrhage significantly increased the number of transfusions. However, after day 20, rHuEPO significantly reduced the number of erythrocyte transfusions in these patient groups, as well as reducing incompatibility in the major ABO-blood group. For the whole study period, rHuEPO reduced the transfusion requirements in GVHD III and IV from 18.4 +/- 8.6 to 8.5 +/- 6.8 U (P = .05). After autologous BMT, there was no difference in the time to independence from erythrocyte transfusions and in the regeneration of reticulocytes. Marrow purging strongly increased the requirement for transfusions as well as the time to transfusion independence.

ABO Blood-Group System↗
PubMed1994

High-dose consolidation with local radiation and bone marrow rescue in patients with advanced neuroblastoma.

Twenty-six children with advanced neuroblastoma were consolidated with cisplatin, BCNU, etoposide, melphalan, 21 Gy of local radiotherapy, and bone marrow rescue in a multicenter study. All patients were over 1 year of age at diagnosis. Twenty-two patients were treated in first complete or partial remission and four in second complete or partial remission. Hematologic rescue was autologous (n = 23), allogeneic (n = 2), or syngeneic (n = 1). Extrahematological toxicity involved primarily the gastrointestinal mucosa. Among five fatal toxicities, three included intestinal hemorrhage. Fourteen patients relapsed after BMT, four of them at the primary site. Seven children survive progression-free after 16-56 months. These results are essentially not different from a single-center study with the same protocol or from other published studies. The value of megatherapy for patients with advanced neuroblastoma or for a subgroup of them can only be established on a larger number of patients than most national trials accrue.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1994

Diagnostic value of the molecular genetic detection of the t(11;22) translocation in Ewing's tumours.

One consistent feature of the Ewing's tumour family is the presence of a balanced translocation involving band q12 and band q24 of chromosome 22 and chromosome 11. Recent cloning of the chromosome breakpoint regions of t(11;22)(q24;q12) Ewing's sarcoma translocation has revealed that the breakpoints were localized within the Ewing's sarcoma gene (EWS gene) on chromosome 22 and the Fli-1 gene on chromosome 11. Molecular genetic techniques can thus be applied to the detection of the t(11;22) translocation in Ewing's tumours. By reverse transcription and polymerase chain reaction technique (RT-PCR) 11 Ewing's tumour derived cell lines, 12 primary Ewing's tumours, and 11 tumours after treatment were analysed for the occurence of the t(11;22) translocation. Furthermore, blood and bone marrow samples from 5 patients were available for RT-PCR. In 78% of the cell lines and 91% of the primary Ewing's tumours the t(11;22) translocation was detectable by RT-PCR. In bone marrow samples from a Ewing's sarcoma patient presenting in relapse tumour cells were detected by molecular genetic analysis. Our results indicate that molecular genetic detection of the t(11;22) translocation is valuable in the differential diagnosis of small round cell tumours and will provide important information for the staging and prognosis of Ewing's tumour.

Base Sequence↗
PubMed1994

[Molecular genetic detection of t(11;22)(q24;12) translocation in Ewing sarcoma and malignant peripheral neuroectodermal tumors].

Ewing's sarcomas and malignant peripheral neuroectodermal tumors (MPNTs) show very little evidence of differentiation and lack characteristic morphological features at the light-microscopic level. These malignancies have always presented a significant differential diagnostic challenge to the pathologist. Electron microscopy, immunohistochemical staining for neural antigens such as neuron-specific enolase (NSE), Leu 7, synaptophysin and, more recently, the detection of Mic-2 gene expression have been included in the routine histopathological diagnostic procedure. However, the expression of these antigens is not restricted to this entity. Thus, further modalities are required to prove diagnostic reliability. One consistent feature of the Ewing's sarcoma family is the presence of the reciprocal chromosomal t(11;22)(q24;q12) translocation. Recent cloning of the t(11;22) break point has led to the identification of the genes involved in this translocation. This provides the possibility of molecular genetic detection of the t(11;22) translocation in Ewing's sarcomas and MPNTs. We have established a method using reverse transcription and the polymerase chain reaction (RT-PCR) for the detection of the specific gene fusion transcript caused by the 11;22 translocation. The validity of our approach was proved by analyzing Ewing's tumor cell lines and tissue material obtained from primary biopsies and tumor resections. Molecular genetic detection of the 11;22 translocation by RT-PCR analysis should perhaps be included in the diagnostic work-up of suspected Ewing's sarcoma and MPNT.

Bone Neoplasms↗
PubMed1994

Activation of protein kinase C induces de novo synthesis of the soluble interleukin-6 receptor in human B cells.

The mechanism of protein kinase C (PKC) induced release of the soluble interleukin-6 receptor (sIL-6R) from human B cells was investigated. Phorbol myristat acetat (PMA)-induced activation of PKC significantly enhanced the release of sIL-6R from the human B-cell line SKW 6.4. The PMA effect was completely blocked by cycloheximide, whereas different inhibitors of proteases had no effect. In contrast to the effect on sIL-6R release, FACS analysis did not reveal any effect of PMA on the expression of IL-6R on the surface of SKW 6.4 cells. After 6 h of stimulation with PMA, analysis of mRNA expression using a polymerase chain reaction-(PCR)-assisted mRNA amplification assay, showed increased expression of a spliced mRNA encoding for a soluble form of IL-6R. Comparable to the results in SKW 6.4 cells, activation of purified human B cells with PMA induced a significant augmentation of sIL-6R release which was also sensitive to cycloheximide. In conclusion, a novel mechanism of sIL-6R release is reported involving de novo synthesis. Thus, sIL-6R release from human B cells is completely different compared with that described in hepatocytes, which involved rapid, proteolytic cleavage of the membrane-bound receptor but not de novo synthesis. The results of this study may help to understand the molecular control of sIL-6R release from human B cells.

B-Lymphocytes↗
PubMed1994

[Detection of EWS-/FLI-1 gene fusion transcripts by RT-PCR as a tool in the diagnosis of tumors of the Ewing sarcoma group].

Recent cloning of the chromosome breakpoint regions of the reciprocal chromosomal t(11;22) (q24;q12) has revealed that the breakpoints were localized within the EWS gene (Ewings sarcoma gene) on chromosome 22 and the FLI-1 gene on chromosome 11. Thus, molecular genetic techniques were applicable for the detection of this genetic aberration, which occurs as a consistent feature of the Ewings tumor family. By reverse transcription and polymerase chain reaction technique (RT-PCR) in 78% of Ewings sarcoma derived cell lines, and in 91% of primary Ewings tumor tissue t(11;22) specific EWS/FLI-1 fusion transcripts were detected. Furthermore, in bone marrow samples from an Ewings sarcoma patient contaminating tumor cells could be shown by RT-PCR. Our results indicate that molecular genetic detection of the t(11;22) translocation opens a new modality for the differential diagnosis and the staging of Ewings tumor patients.

Base Sequence↗