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Biomedical subjects

A Zoubek

Publications and source records attributed to A Zoubek.

At least 55 records · Page 3Linked to original sources
PubMed1996

Does expression of different EWS chimeric transcripts define clinically distinct risk groups of Ewing tumor patients?

PURPOSE: Because of the high heterogeneity of EWS gene fusions with FLI1 and ERG genes due to variable chromosomal breakpoint locations in Ewing tumors (ET) (14 different chimeric transcripts identified so far), we evaluated the clinical impact of the expression of diverse fusion transcripts in ET patients. PATIENTS AND METHODS: In a European multicenter study, 147 ET were analyzed by reverse-transcriptase polymerase chain reaction (RT-PCR) and the molecular data statistically compared with all clinical data available. RESULTS: Most tumors expressed chimeric transcripts with fusion of EWS exon 7 to FLI1 exon 6 (75 of 147) (type I) or five (39 of 147) and EWS exon 10 to FLI1 exon 5 (eight of 147) or 6 (five of 147). In five cases, chimerism between EWS exon 9 and FLI1 exons 4 and EWS exon 7 and FLI1 exon 7 or 8 was observed. Fifteen cases of EWS-ERG rearrangement were identified. In 85 of these patients treated in the European Cooperative Ewing Sarcoma Studies, molecular results were analyzed in comparison to age, sex, tumor localization, tumor volume, and disease extension. No significant correlation between the various fusion types and these features were observed. Relapse-free survival (RFS) for the 31 patients with localized disease and fusion type I tended to be longer compared with the 24 patients with localized tumors bearing other chimeric transcripts (P = .04). CONCLUSION: Results suggest a possible advantage in PFS for patients with localized disease and fusion type I transcripts, although this will require prospective validation with a larger number of patients and longer follow-up periods.

Adolescent↗
PubMed1995

High nm23-H1/NDPK-A expression in Ewing tumors: paradoxical immunohistochemical reactivity and lack of prognostic significance.

Expression of nm23-H1/NDPK-A has been reported to correlate inversely with metastasizing potential of rodent experimental cells and some human tumors. In the search for reliable molecular prognostic indicators for Ewing tumors (ET), a group of aggressive presumably neuroectodermal malignancies in children and adolescents, we studied nm23-H1/NDPK-A expression. Northern-blot and RT-PCR analyses were employed to semi-quantificatively measure nm23-H1 mRNA levels in ET cell lines and tissue extracts. A panel of monoclonal antibodies (MAbs) were used to evaluate protein abundance by Western blotting and immunohistochemistry. The nm23-H1/NDPK-A gene was also investigated on the DNA level to define possible genomic alterations. Our results revealed neither nm23-H1 allelic loss nor gene amplification and failed to show any significant variation in nm23-H1 mRNA or NDPK-A protein levels of primary or metastatic ET. NDPK-A protein levels were high and comparable to those of MCF-7 breast-cancer cells and to aggressive stage-IV neuroblastoma cell lines. nm23-H2/NDPK-B expression in ET was slightly more variable but generally lower than in MCF-7 cells. In the immunohistochemical analysis, however, discrepancies in the reactivity patterns with different antibodies were observed. Differential sensitivity to various fixation methods and heat treatment pointed to a structurally polymorphic NDPK-A protein. nm23-H1 expression studies using immunohistochemistry for prognostic counselling should thus be interpreted with caution.

Adolescent↗
PubMed1995

Detection of tumour cells in peripheral blood and bone marrow from Ewing tumour patients by RT-PCR.

The Ewing family of tumours (ET) is characterised at the cytogenetic level by unique chromosome 22 rearrangements. The breakpoints have been cloned and were shown to fuse the EWS gene on chromosome 22 to one of two closely related ETS proto-oncogenes, FLI-I or ERG, which reside on chromosomes II and 21, respectively. The rearrangement results in the expression of chimaeric transcripts, which can be identified by means of reverse transcriptase-polymerase chain reaction (RT-PCR). We applied this method for the monitoring of ET cells circulating in the peripheral blood or infiltrating the bone marrow. The presence of tumour cells could be detected with a sensitivity of I in I x 10(6) nucleated cells. When samples were kept at 4 degrees C, tumour cells could still be identified after 48 hr of storage. Positive RT-PCR signals originated from intact ET cells rather than from free RNA released by ruptured tumour cells. We analysed peripheral blood, bone marrow samples and peripheral blood stem cell collections from 16 ET patients. At diagnosis, bone marrow specimens collected from 6 patients and I peripheral blood specimen tested positive for EWS chimaeric RNA. During therapy tumour cells were detected in bone marrow aspirations obtained from 2 patients. Our results show that ET cells infiltrating the bone marrow or circulating in peripheral blood can be identified by RT-PCR. The clinical implications for the presence of ET cells in samples detected by RT-PCR at diagnosis and during therapy requires further evaluation.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1995

Response of untreated stage IV Wilms' tumor to single dose carboplatin assessed by "up front" window therapy.

A total of nine children with previously untreated stage IV Wilms' tumor of favorable histology were treated according to the Austrian/Hungarian Wilms' Tumor Protocol 89 and received a preoperative single dose of carboplatin as an "up front" window therapy. The treatment consisted of carboplatin as a single-dose of 600 mg/m2 over 30 minutes on day 1. Response evaluation by chest X-ray, serial CT scans, and sonography was performed on day 22. Investigation of the abdominal tumors revealed seven partial responses (78%), one nonresponse, and one progressive disease with a median tumor volume reduction of 62%. Response of metastases evaluated by CT scans was as follows: four complete remission, four partial response, and one nonresponse. Thrombocytopenia (WHO grade III 1, grade II 2, grade I 2) and leukocytopenia (WHO grade II 1, grade I 5) were the main side effects. No renal or liver toxicity were observed. The overall response rate after a preoperative single-dose of 600 mg/m2 carboplatin in untreated patients with stage IV Wilms' tumor is encouraging and the toxicity acceptable. This data indicate that carboplatin seems to be an additional effective drug in patients with previously untreated Wilms' tumor of favorable histology.

Austria↗
PubMed1995

Recombinant human granulocyte-macrophage colony-stimulating factor in septic neutropenic pediatric cancer patients: detection of circulating hematopoietic precursor cells correlates with rapid granulocyte recovery.

Cycling intensive chemotherapy currently used to treat pediatric solid tumors induces severe neutropenia. Prolonged neutropenia is a major risk factor for septic death which occurs in up to 5% of febrile or septic neutropenic episodes. We treated 18 neutropenic pediatric cancer patients (eight females, 10 males) during 30 febrile and/or septic episodes with single daily doses of E. coli-derived non-glycosylated recombinant human granulocyte-macrophage colony-stimulating factor (rh-GM-CSF, 5 micrograms per kg of body weight). The cytokine was administered for a median period of 6.5 days (2-12 days). Analysis of circulating hematopoietic progenitor cells was performed at day 1 (baseline) and day 5 of rh-GM-CSF treatment and included flow cytometric CD34 analysis as well as the methylcellulose-based clonogenic assay. Prompt hematopoietic recovery and resolution of septic problems was observed in all children. The counts of leukocytes (WBC), absolute neutrophils (ANC), and platelets (PLT) rose above 1,000/microL, 1,000/microL, and 50,000/microL within 4 days (0-9), 5.5 days (2-13), and 6 days (0-14), respectively. Faster granulocyte recovery and improved recruitment of circulating hemopoietic precursors was observed in children with detectable amounts (> 0.1%) of CD34-positive mononuclear cells prior to rh-GM-CSF treatment. We conclude that, to some extent, the efficacy of rh-GM-CSF treatment in neutropenic cancer patients is influenced by the hematopoietic recovery status on the progenitor cell level. Although they respond more slowly to the treatment, patients without circulating CD34-positive progenitor cells may gain most from growth factor therapy. Rh-GM-CSF can be safely administered to febrile and/or septic neutropenic children treated for cancer.

Adolescent↗
PubMed1995

First experience with prognostic factors in unselected neuroblastoma patients. The Austrian Neuroblastoma 87 Study.

Between January 1987 and December 1993, 117 patients were registered in the Austrian A-NB87 study. The male/female ratio was 1.18, with 50 patients below the age of 1 year at diagnosis. Patients were assigned to stage according to the result of primary surgery in localised disease. Age, ferritin and neuron specific enolase were used in addition in stage III disease for risk-adapted treatment. Adrenal or pelvic primary tumour sites were mainly associated (81%) with advanced disease. The median observation time of the study is 3.5 years. The overall survival at 3 years was excellent in low stage disease and IVs patients, i.e. 100% for stage I and IIA (20 patients), 92% in stage IVs (13 patients), 81% in stage IIIA (18 patients) and 69% in stage IIB (8 patients). Stage IV (38 patients) showed a survival rate of 51%, whereas stage IIB (10 patients) had the worst outcome in this study, i.e. 20%, due to treatment-related toxicity. Significant unfavourable prognostic factors were neuron specific enolase (NSE) > 100 ng/ml, ferritin > 300 micrograms/ml and amplified MYCN. This study achieved a better survival rate in stage IV patients and a subgroup of stage III in comparison to our previous study (Pädiatrie und Pädologie 1986, 21, 269) and gives the basis to further reduce treatment intensity in low-risk disease based on biological factors. However, prognosis for high-risk cases was still poor in spite of a very aggressive treatment concept.

Age Factors↗
PubMed1995

Ewing tumor after treatment of Ki-1+ anaplastic large cell lymphoma. Therapy-associated secondary neoplasm or unrelated coincidence?

We report on a 20-year-old woman who developed a pelvic small round cell tumor with lung metastases 8 years after diagnosis and successful treatment for Ki-1-positive anaplastic large cell lymphoma (Ki-1+ ALCL) with histiocytic differentiation. Molecular genetic detection of EWS/FLI-1 fusion gene expression in the second tumor by RT-PCR unambiguously confirmed the histopathologic diagnosis of Ewing tumor (ET), whereas no evidence for the presence of this specific gene rearrangement was obtained in a retrospective analysis of the lymphoma tissue. In contrast, expression of a NPM/ALK chimeric gene was observed which was absent in the ET. Moreover, the lymphoma contained a monoallelic D delta 2-D delta 3 T-cell receptor gene rearrangement which was also absent in the ET. Thus, our histopathologic, immunohistochemical, and, in particular, molecular genetic studies support the notion that these tumors were most probably pathogenetically unrelated. Since this is the first report describing such an association between a non-Hodgkin's lymphoma and ET and, since the latter has only rarely been observed as a second malignant neoplasm, it remains a matter of speculation whether in this patient ET developed as a therapy-related secondary neoplasm or independently from the lymphoma as a consequence of either genetic tumor predisposition or mere accidental coincidence.

Base Sequence↗
PubMed1994

Detection of numerical and structural chromosome abnormalities in pediatric germ cell tumors by means of interphase cytogenetics.

In contrast to the cytogenetically well characterized testicular germ cell tumors (GCT) in adults, reports on cytogenetic studies in pediatric GCT are scarce. The presence of an i(12p) and numerical abnormalities involving chromosome 12 are the most frequent cytogenetic changes in GCT of adults. We have performed in situ hybridization (ISH) studies on paraffin sections and on isolated nuclei of 13 pediatric GCT with particular emphasis on those chromosome abnormalities that are common in adult GCT. These include numerical and structural abnormalities of chromosomes 1 and 12 as well as numerical deviations of chromosomes 8, 10, X, and Y. The histological subsets of the tumors investigated included two dysgerminomas (DGE), one seminoma (SE), two embryonal carcinomas (EC), four mixed and two pure yolk sac tumors (YST), and one undifferentiated (IT) and one differentiated teratoma (TD). Similar to the GCT in adults, additional copies of chromosome 12 were the most frequently observed numerical abnormalities. In contrast to the findings in adult GCT, changes in the size of the pericentromeric hybridization signals of chromosome 12, suggesting the presence of i(12p) chromosomes, were found in only two cases. No chromosome abnormalities were found in the pure TD or in the TD cells of mixed tumors containing a YST component. In the YST portion, however, Ip deletions and/or numerical chromosome changes were present. Surprisingly, deletions of the short arm of chromosome I, del(I)(p36.3), were frequent in pediatric GCT and were the sole abnormality detected in two cases. The Ip36 deletions were present in all stage-IV EC and YST investigated and were absent in the relatively benign TD and in one YST stage-I. Therefore, Ip36 deletions may have value as a prognostic marker in pediatric GCT.

Adolescent↗
PubMed1994

Tolerance of high doses of amphotericin B by infusion of a liposomal formulation in children with cancer.

Conventional amphotericin B (Amph-B) is the drug of choice for treating systemic fungal infections. Recently, a new formulation has become available, encapsulated in liposomes (Amph-lip). This new form of administration was developed in order to lower the acute side effects and to offer the possibility of administering high doses of amphotericin B. Experience with Amph-lip is limited, especially in children. We treated four children with documented systemic fungal infections with Amph-lip and administered it empirically to 12 children. Fifteen of these 16 children were severely granulocytopenic oncologic patients. One 3-month-old baby suffered from systemic candidiasis. Amph-lip was preferred to conventional Amph-B in children with organ dysfunction developing as a consequence of conventional chemotherapy or bone marrow transplantation, after failure of conventional Amph-B to improve a fungal infection, and after adverse drug reactions had occurred. The daily doses of Amph-lip ranged from 1 to 6 mg/kg (median 3 mg/kg), the cumulative doses from 13 to 311 mg/kg (median 75 mg/kg). Acute adverse reactions or organ function abnormalities attributable to Amph-lip did not occur in 402 administrations. Amph-lip has proven to be well tolerated by children in terms of acute toxicity and in the long term. Although large cumulative doses were given, organ function abnormalities attributable to Amph-lip doses were not detected in any of ten long-term survivors over a median observation time of 36 months (range 30-44 months). Amph-lip appears to be a promising alternative antifungal treatment, especially for patients with impaired organ function, when high doses of amphotericin B are necessary.

Adolescent↗
PubMed1994

Variability of EWS chimaeric transcripts in Ewing tumours: a comparison of clinical and molecular data.

Ewing tumours (ET), including Ewing's sarcoma and peripheral primitive neuroectodermal tumour, are well characterised at the molecular level by a unique chromosomal rearrangement which fuses the EWS gene to one of two closely related ETS proto-oncogenes, FLI-1 or ERG. Expression of the resulting chimaeric transcripts can be readily detected by reversed transcriptase polymerase chain reaction (RT-PCR). This approach led to the identification of a number of different exon combinations at the junction site of coding sequences. The physiological consequences of the observed variability in the hinge region of EWS chimaeric proteins are not known. We have analysed tumour-derived material from 30 ET patients with well-documented clinical course (18 with localised and 12 with metastatic disease at diagnosis) for the presence of EWS/FLI-1 or EWS/ERG RNA. Karyotypes were obtained in 21 out of 27 cases and analysed by routine cytogenetics. A chromosome 22 rearrangement was demonstrated in 18 cases (67%). In contrast, RT-PCR revealed the presence of chimaeric transcripts in 28 tumours (93%), with fusions of EWS exon 7 to FLI-1 exons 6 (19/28), 5 (4/28) and 7 (1/28). In addition, EWS/FLI-1 exon combinations 10/5 and 9/4 were observed in one case each. In the last tumour, the presence of at least four additional splicing variants corresponding to fusion of EWS exon 7 to FLI-1 exons 4, 6, 8 and 9 was demonstrated. Two tumours expressed EWS/ERG fusion transcripts involving EWS exon 7 and ERG exon 6. In this study, EWS/FLI-1 exon combinations 7/6 (type I) predominated over 7/5 (type II) in localised ET (14 versus 1) and were more abundant in tumours affecting the long bones (9 versus 0), whereas in central axis tumours and metastatic disease there was only little difference in the frequency of the two types. So far, no correlations between different chimaeric EWS transcripts and any other clinical parameters have been identified.

Adolescent↗
PubMed1994

Successful bone marrow transplantation in a boy with X-linked lymphoproliferative syndrome and acute severe infectious mononucleosis.

We report a 5.9-year-old boy with X-linked lymphoproliferative syndrome (XLP) who presented with acute severe infectious mononucleosis. Clinical symptoms rapidly improved after chemotherapy with etoposide. Allogeneic bone marrow transplantation (BMT) was performed after conditioning with etoposide, busulfan and cyclophosphamide. After successful hematopoietic recovery we were able to demonstrate seroconversion from an impaired antibody response to Epstein-Barr virus (EBV) to a normal antibody-producing state in an immunocompetent child. The only post-transplant complication was mild acute graft-versus-host disease (GVHD). Three years after BMT, the boy is healthy and shows no signs of immunodeficiency. This is the first report on successful allogeneic BMT in the severe course of acute infectious mononucleosis in a patient with XLP. We speculate that the application of etoposide contributed to the positive outcome in this patient.

Acute Disease↗
PubMed1993

Association of hepatitis C virus infection with chronic liver disease in paediatric cancer patients.

A total of 203 paediatric cancer treatment survivors were tested for serum antibodies against hepatitis-C virus (anti-HCV). Anti-HCV was detected in 41 patients (20.2%) with first generation anti-HCV ELISA. Positive results were confirmed in all samples retested with a second generation ELISA (n = 35) and in all but two cases re-analysed by immunoblotting (n = 23). Anti-HCV positive children had received significantly more blood product transfusions compared to seronegative patients. In 75 children (32%) chronic liver disease was found. It was defined as an elevation of serum alanine aminotransferase values to a least 2.5 times the upper limit of normal persisting for 6 months or longer. Hepatitis A was never detected, and in 58 children the chronic hepatopathy was unexplained by hepatitis B (non-A non-B chronic liver disease). Of these patients 29 (50%) were seropositive for anti-HCV. Surprisingly, non-A/non-B chronic liver disease was associated with anti-HCV in 14 of 19 solid tumour patients (78.9%), but in no more than 14 of 39 leukaemia and lymphoma patients (35.9%). This phenomenon was not explained by different rates of cytomegalovirus disease and drug toxicity related hepatopathies between the two groups. It may be related to differences of leukaemia/lymphoma compared to solid tumour therapy schedules (differential immunosuppression and liver toxicity).

Child↗
PubMed1993

Ondansetron in the control of chemotherapy-induced and radiotherapy-induced emesis in children with malignancies.

The management of chemotherapy-induced nausea and emesis presents a major problem in children with cancer. The anti-emetic properties of the 5-HT3 receptor antagonist ondansetron are well documented in adults receiving cytotoxic chemotherapy. Experience in the treatment of children is still limited. Here we present a review of the literature on the anti-emetic treatment with ondansetron in children. Moreover, we provide recommendations on the use of ondansetron during anti-neoplastic chemotherapy and radiotherapy in pediatric oncology.

Adolescent↗
PubMed1993

Narrow spectrum of infrequent p53 mutations and absence of MDM2 amplification in Ewing tumours.

The p53 and MDM2 genes are part of a physiological pathway frequently impaired in human cancer. With the exception of tumours occasionally associated with hereditary predisposition, childhood malignancies have not been studied in detail yet. This is the first report on the analysis of p53 and MDM2 in a group of non-hereditary paediatric neoplasms referred to as the Ewing tumours (ETs). Thirty-seven primary tumours and cell lines from 19 patients were screened for the presence of p53 mutations. Only 5% of the primary tumour specimens were found to carry an alteration within this gene. However, p53 mutations were 10-fold enriched in ET cell lines, thus indicating a selective growth advantage in vitro. Strikingly, five out of nine alterations detected were missense mutations within codon 273, which were previously reported to impair only partially the normal p53 function. Two single-base substitutions occurred at codons 277 and 176, and two alterations were loss-of-function mutations. Investigation of the MDM2 gene revealed neither gene amplification in the primary tumours and cell lines nor significant overexpression in any of the cell lines. Our data therefore suggest that impairment of cellular mechanisms involving p53 is rare in a distinct group of childhood malignancies.

Base Sequence↗
PubMed1992

[Veno-occlusive disease of the liver as a treatment complication in children with Wilm's tumor].

We report on three children aged 1 1/2, 2 and 9 1/2 years with Wilms' tumor, who developed a tender hepatomegaly and ascites associated with elevated liver enzymes, anemia and thrombocytopenia during chemotherapy. This clinical picture and liver sonography abnormality are best explained by veno-occlusive disease (VOD) of the liver, while other causes of liver disease could not be identified. Actinomycin D dosage was 0.045 mg/kg as bolus injection in two patients and 0.075 mg/kg split over five days in a third patient. Presumable, this drug was the causative agent. VOD was observed after preoperative and postoperative chemotherapy. No child had received abdominal irradiation. The authors comment on the influence of Actinomycin D as the cause for this unusual liver toxicity.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1991

[Autologous bone marrow transplantation in children with acute leukemia or non-Hodgkin's lymphoma].

More than 95% of children with acute lymphoblastic leukemia (ALL) achieve complete remission with conventional chemotherapy and 60 to 70% are cured. In contrast, only 70 to 80% of children with acute myeloid leukemia (AML) achieve remission and 30 to 40% are cured. In acute leukemia, ALL and AML, high initial white blood cell counts, poor initial response to therapy, certain structural chromosomal abnormalities, and diagnosis under 1 year of age indicate an increased risk of relapse. Prognosis is poor in children, who relapse during treatment. If no bone marrow donor is available, high dose chemo(radio)therapy and autologous stem cell rescue can be applied in these children to consolidate second remission. Furthermore, autologous bone marrow transplantation may be used to consolidate first remission of individual children, who suffer from acute leukemia with high risk criteria. 19 children with a median age of 8 years (0.5 to 19 years) underwent high dose chemo(radio)therapy and autologous bone marrow and/or blood derived stem cell rescue. 11 suffered from ALL, 4 had AML, and 4 suffered from Non Hodgkin's lymphoma (NHL). 7/13 children (54%), who were in first or second remission after early relapse, are alive in continued remission for median 24 months (9 to 44) after autografting. Children in more advanced stage of disease had no benefit from high dose therapy and autologous stem cell rescue.

Adolescent↗