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Biomedical subjects

H Gadner

Publications and source records attributed to H Gadner.

At least 145 records · Page 8Linked to original sources
PubMed1996

Role of ploidy, chromosome 1p, and Schwann cells in the maturation of neuroblastoma.

BACKGROUND: Neuroblastoma is a heterogeneous disease, with manifestations ranging from spontaneous regression to lethal spread. Sometimes the tumor spontaneously differentiates toward a benign ganglioneuroma (maturing neuroblastoma). The prognosis is frequently related to ploidy, deletions in the short arm of chromosome 1, and amplifications of the N-myc oncogene. Maturing neuroblastomas consist of both neuronal cells and Schwann cells. We investigated the genetic composition of both cell types in maturing neuroblastomas, to determine the relation between genetic abnormalities and maturation. METHODS: We studied 20 maturing and mature neuroblastomas by in situ hybridization to count the chromosomes and evaluate possible deletions in the short arm of chromosome 1 in neuronal and Schwann cells. The DNA content of the cells was measured by flow cytometry. RESULTS: Neuroblastic and ganglionic cells showed aberrations in the number of chromosomes. In situ hybridization and flow cytometry demonstrated near-trip-loidy in 18 of 19 tumors and pentaploidy in the remaining tumor. The Schwann cells in all 20 neuroblastomas contained normal numbers of chromosomes. In 18 tumors studied, there were no chromosome 1 deletions in either type of cell. CONCLUSIONS: The Schwann cells in maturing neuroblastomas differ genetically from the neuronal cells. The normal number of chromosomes in Schwann cells and the abnormal number in neuroblastic ganglionic cells suggests that Schwann cells are a reactive population of normal cells that invade the neuroblastoma. Near-trip-loidy of neuroblastoma cells and intact chromosome 1 are presumably genetic prerequisites for spontaneous organoid maturation, because we found no diploidy or chromosome 1 depletions in the neuronal cells of spontaneously maturing neuroblastomas.

Child↗
PubMed1996

All-trans retinoic acid and short-time, high-dose cytarabine in two children with acute promyelocytic leukemia.

We report on two girls, 3 and 13 years old, with acute promyelocytic leukemia (APL) who were successfully treated with all-trans retinoic acid (ATRA) 45 mg/m2/day. "Retinoic acid syndrome" was prevented with short-time treatment of high dose (4 x 1.5 g/m2) cytarabine. This regimen was well tolerated, although both children were critically ill. They achieved a complete remission confirmed by light microscopy, but reverse transcriptase polymerase chain reaction remained positive after ATRA, underlining the need of further chemotherapy.

Adolescent↗
PubMed1996

Demonstration of the translocation der(16)t(1;16)(q12;q11.2) in interphase nuclei of Ewing tumors.

The der(16)t(1;16) has been detected cytogenetically in a number of malignancies including Ewing tumors (ETs). To enable fast and reliable analysis of der(16) chromosomes, we established an interphase cytogenetic approach. By using two DNA probes hybridizing to the heterochromatic portions on the long arms of chromosomes 1 and 16, this technique allows the detection of this chromosomal aberration in nonproliferating cells. Formation of the der(16) leads to partial excess of 1q material and partial loss of the long arm of chromosome 16. Double-target fluorescence in situ hybridization (FISH) experiments were performed on cytospin slides of 13 ETs, near-triploid tumor cells and normal cells to assess whether the FISH technique used permits the discrimination of nuclei harboring this aberration from nuclei without a der(16) chromosome. In five ETs, we found evidence for the presence of one or two der(16)t(1;16) chromosomes both by FISH and by conventional cytogenetics. Tumor cells displayed two signals for intact chromosomes 1, one or two additional fused signals for the der(16) chromosomes, and one signal for the intact chromosome 16. In one case without fused signals, the presence of a der(16) was demonstrated by hybridizing a painting probe for chromosome 16 simultaneously with the paracentromeric probe for chromosome 1. Our results suggest that double-target FISH on interphase nuclei offers an ideal tool for analyzing tumors prospectively and retrospectively to assess the biological role and the possible prognostic impact of the der(16) in ETs and in other solid tumors.

Adolescent↗
PubMed1996

Mobilization of tumour cells during biopsy in an infant with Ewing sarcoma.

UNLABELLED: Ewing sarcoma and the closely related peripheral primitive neuroectodermal tumour, recently referred to as Ewing tumour (ET), are characterised by unique gene rearrangements on chromosome 22. The breakpoints have been cloned and shown to fuse the Ewing sarcoma gene to one of two closely related ETS proto-oncogens, FLI-1 or ERG, which reside on chromosomes 11 and 21, respectively. The rearrangement results in the expression of specific hybrid transcripts which can be detected with high sensitivity by the reverse transcriptase polymerase chain reaction technique (RT-PCR) in primary tumours, blood and bone marrow. We report on a 7-month-old boy with a pelvic Ewing sarcoma in whom circulating tumour cells were identified in the peripheral blood during open tumour biopsy by RT-PCR. However, before and 6 days after surgery no tumour cells could be detected in the peripheral blood. CONCLUSION: The application of RT-PCR to monitor shedding of tumour cells during surgical intervention will help to evaluate if open biopsy potentially contributes to metastatic tumour cell spread.

Base Sequence↗
PubMed1996

Screening for neuroblastoma in late infancy by use of EIA (enzyme-linked immunoassay) method: 115000 screened infants in Austria.

The aim of this study was to investigate the feasibility of a neuroblastoma screening programme for children in late infancy, based on collaboration of general paediatricians and practitioners in Austria, using the technique of enzyme-linked immunoassay (EIA) for biochemical analyses. Analysis of catecholamine metabolites in spot urine samples by EIA with high performance liquid chromatography as a backup was undertaken. Austrian infants (median age 8.7 months) were screened. Overall compliance was 30%. The EIA method had a high rate (6.7%) of false-positive results. 28 infants were admitted to hospital. In 15 cases, neuroblastoma was found (four stage 1, five stage 2B, six stage 3). The EIA method can be used for neuroblastoma screening, but requires a backup analytical technique in order to avoid unnecessary hospital admissions. The stage distribution and biological features of neuroblastomas diagnosed by screening at a later age are different from those detected by earlier screening. Screening in late infancy might be of more benefit than early screening.

Austria↗
PubMed1996

Variability of nm23-H1/NDPK-A expression in human lymphomas and its relation to tumour aggressiveness.

The nm23-H1 gene is a putative metastasis-suppressor gene encoding a 17 kDa protein with nucleoside diphosphate kinase activity. Expression of nm23-H1/NDPK-A correlates inversely with the metastasising potential of some human tumours and experimental animal cells. No nm23 expression studies exist for human malignant lymphomas so far. In this study, we examined nm23-H1 expression by Northern and immunohistochemical analysis in 106 primary lymphoma samples from patients with Hodgkin's disease (HD) (n = 15), high-grade non-Hodgkin's lymphoma (NHL) from different lineages (n = 71) and low-grade NHL (n = 20). Both inter- and intra-subtype variations in nm23-H1/NDPK-A expression levels were demonstrated by all disease subtypes. Besides this heterogeneity, a general trend towards highly malignant samples expressing higher nm23-H1/NDPK-A, levels than the low-grade lymphomas was observed. Both adult and childhood HD and high-grade NHL samples exhibited significantly higher NDPK-A expression than the low-grade NHL found only in adults. High nm23-H1/NDPK-A levels in lymphoma samples did not always reflect proliferative activity of tumour cells as monitored by Ki-67 antigen staining. Fifty samples were further investigated for possible mutations in the nm23-H1 coding sequence by means of reverse transcriptase-polymerase chain reaction (RT-PCR) and single-strand conformation polymorphism (SSCP) analysis. No mutation was found by this screening. Our results suggest a role for nm23-H1 expression in the disease aggressiveness of lymphomas.

Adolescent↗
PubMed1996

NPM/ALK gene fusion transcripts identify a distinct subgroup of null type Ki-1 positive anaplastic large cell lymphomas.

The chromosomal aberration t(2:5) resulting in the juxtaposition of NPM and ALK genes is a well-known feature of several Ki-1+ anaplastic large cell lymphomas (ALCL) of the T-cell type. However, conflicting results have been reported concerning the presence of this gene rearrangement in other ALCL and Hodgkin's disease (HD), respectively. We performed NPM/ALK RT-PCR on 14 cases of ALCL expressing distinct myelomonocytic markers, e.g. CD11c, CD13, CD14 or CD68, but neither T-cell nor B-cell associated antigens (null cell phenotype). The specific translocation was found exclusively in six childhood tumours previously diagnosed as malignant histiocytosis (MH), whereas all adult lymphomas (three ALCL without characteristics of MH, three secondary ALCL following HD) and two paediatric cases of secondary ALCL following HD did not show NPM/ALK gene fusion products. By Southern blotting, the status of T-cell receptor (TCR) and immunoglobulin heavy chain genes (IgH) were investigated; two patients with initially diagnosed MH had the TCRdelta-chain gene rearranged (Ddelta2-Ddelta3 and Vdelta1-Jdelta1, respectively). IgH rearrangements were detected in only one patient with secondary ALCL. Our data indicate a high association of previously diagnosed MH and NPM/ALK gene rearrangements. In one case, this specific translocation was demonstrated at an early stage of development; in another, a mature TCRdelta-chain gene rearrangement was detected. These data support the hypothesis of a lymphoid origin of this subgroup of Ki-1 positive ALCL previously diagnosed as MH.

Adolescent↗
PubMed1996

Lack of DNA synthesis among CD34+ cells in cord blood and in cytokine-mobilized blood.

Flow cytometric DNA analysis was performed in combination with three-colour immunological staining of cell surface antigens on density-separated mononuclear cells (MNC) obtained from peripheral blood (PB) before, during and after cytokine stimulation of healthy adults. The aim of the study was to determine the cell-cycling status of haemopoietic progenitor cells mobilized into the blood of healthy volunteers during a 5 d treatment period with 5/micrograms per kg body weight of either granulocyte colony-stimulating factor (G-CSF) or granulocyte-macrophage colony-simulating factor (GM-CSF). Despite considerably increasing numbers of CD34+ PB MNC, the latter were not found to be in S/G2M phase, whereas, among the CD34- MNC, the proportion of cells in S/G2M phase increased from < 0.1% to 0.75 +/- 0.4% (GM-CSF) and to 1.34 +/- 0.75% (G-CSF) and dropped again after discontinuation of the cytokine stimulation. These cells expressed CD33 but were negative for CD45RA, CD3, CD19 and CD14 and were thus considered granulopoietic cells. Analogous results were obtained from analyses of cord blood (CB). In contrast, CD34+ cells from bone marrow (BM) were partially (between 9% and 15%) found to be in S/G2M phase. The non-cycling status of PB and progenitor cells was confirmed by the analysis of CD34+ cells enriched from the two cells sources. However, in vitro stimulation of these progenitor cells using IL3, GM-CSF, erythropoietin and steel factor (SF) revealed that, after 48 h in suspension culture, up to 30% of the CD34+ cells were in S/G2m phase. The fact that cycling CD34+ cells are only detectable in BM but not in PB or CB may suggest different adhesive properties of migrating/mobilized 'stem cells' which may require the BM micro-environment for adequate proliferation in vivo.

Adult↗
PubMed1996

[Sarcoma botryoides in the pediatric vagina--a soft tissue sarcoma with good prognosis].

Although rare, sarcoma botryoides of the vagina in infants is a highly aggressive soft tissue tumour. Former opinions suggesting exenterative surgery and radiation to improve the dismal outcome in these young children, are outdated. Due to balanced therapies (topical tumourectomy, chemotherapy and radiation adjusted to tumour stage) cure of these sarcomas may be expected dependent on tumour stage, localisation and response to chemotherapy. The rate of complete remissions has increased in recent years. We report on an eighteen-month old girl with complete remission of tumour stage IIA who had been treated according to the CWS 91 protocol. Diagnosis and treatment were performed in March 1994 at the age of six months. We observed the patient in complete remission for 8 months (till September 1995).

Biomarkers, Tumor↗
PubMed1996

High-resolution FISH of the entire integrated Epstein-Barr virus genome on extended human DNA.

Here we report a high-resolution fluorescence in situ hybridization (FISH) analysis of the integrated Epstein-Barr virus (EBV) genome in chromosomes, decondensed interphase nuclear chromatin, and linearly extended chromatin fibers. We analyzed the EBV DNA integrated into the human genome in the well-characterized Burkitt's lymphoma cell line Namalwa, which contains two complete EBV genomes. The integration occurs via the terminal repeats of the virus and was always detectable at chromosome band 1p35. Using the biotinylated BamHIW fragment of the viral DNA, we observed distinct pairs of signals or small nuclear RNA "tracks" within interphase nuclei. FISH to stretched DNA fibers has a higher resolving power and; therefore, enables analysis of the structural organization of DNA. Application of this methodology to linearly extended chromatin of Namalwa cells using different EBV fragments allowed us to visualize the ordered arrangement of the integrated virus. Based on the predicted span of 0.34 nm per base pair for relaxed DNA, length measurements of 30 images showed a good correlation between the mean physical length of hybridized EBV DNA of 52.8 microns (158 kb) without the terminal repeats, and the EBV genomic length of 172 kb, including the terminal repeats. This DNA mapping procedure represents a useful tool for studying the structural organization of integrated viral genomes, and its application will have implications for the understanding of integration processes.

Burkitt Lymphoma↗
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↗
PubMed1996

The composition of CD34 subpopulations differs between bone marrow, blood and cord blood.

Our previous data obtained by flow cytometry and by clonogenic assay had consistently shown a lower cloning efficiency of hematopoietic progenitor cells in bone marrow (BM) compared to those in blood (PB) or in cord blood (CB). Also, recent clinical reports have described more rapid reconstitution after PB than after BM transplantation. We have applied two- or three-color flow cytometric analysis using monoclonal antibodies directed against the stem- and progenitor cell antigen CD34, in combination with other cell surface markers. We report significant differences in the composition of progenitor cells contained in BM (238 specimens from 53 healthy donors and from patients in remission), PB (301 samples from 92 patients with or without cytokine support) and CB (n = 37). Leukapheresis products (Pher, n = 69) were included in the study as well as positively selected CD34+ cells obtained from BM (BMsel, n = 2), PB (PBsel, n = 28) and CB (CBsel, n = 5). We used monoclonal antibodies directed against CD7, CD19, CD34, CD38, CD45RA and glycophorin A. The highest proportion of CD34+ cells (in % of the MNC) was found in BM (mean 5.37% +/- 4.5). In the other sources, the mean values were 1.79% +/- 2.46 (PB), 1.48% +/- 1.81 (Pher) and 1.1% +/- 1.69 (CB). However, BM was the only source in which a considerable proportion of the CD34+ cells coexpressed the B cell antigen CD19 (mean 30.1%, median 28, range 0 to 84%). The amount of earlier myeloid progenitors as determined by their non-expression of the CD45RA antigen was lowest among BM CD34+ cells (26.7% +/- 16.6). In the other sources, the respective values were 57.5% +/- 17.9 (PB), 63.6% +/- 13.9 (Pher) and 70.4% +/- 16.1 (CB). These results were confirmed by subtype analyses of the CD34+ cells positively selected from the three sources. Enrichment showed minor CD34+ subpopulations to be identified. The mean proportions of B cell progenitors were 0.11% +/- 0.24 (PBsel) and 1.3% +/- 1.42 (CBsel) of the CD34+ cells. The CD34+ cells from all cell sources coexpressed GPA (median 0.15%, range 0 to 1.8%) and CD7 (median 0.25%, range 0 to 1.2%). The proportion of CD38- cells ranged from 0.7 to 4% of the CD34+ MNC. Thus, despite higher CD34 counts in BM, the relative proportions of myeloid progenitors are higher in PB and in CB. This suggests that, if timely reconstitution depends on the number of CD34+ cells transplanted, the mean number of "stem cells' (SC) required is 1.4-fold (for myeloid cells) or 2.2-fold (for earlier myeloid cells) higher for BM than for PB.

Adolescent↗
PubMed1996

[5 years neuroblastoma screening in Austria: rate of participation, results and a comparison with other screening areas].

In late 1990 a screening program for the early detection of neuroblastoma in infants was introduced in Austria. The program is performed on a voluntary basis in collaboration with general pediatricians and practitioners. Filter strips for urine collection are distributed to parents of infants aged seven to nine months on the occasion of a routine check up. The samples are sent to the laboratory by parents and analysed for vanillylmandelic acid (VMA) and homovanillic acid (HVA). Between January 1991 and December 1995 125,201 infants were screened. The compliance rate was 26.8% for Austria, but great differences were seen for different regions (65% in Carinthia, 10% in Vorarlberg). 30 children were admitted to hospital for investigation of repeatedly elevated urine catecholamines. A neuroblastoma was identified in 16 cases. In 12 of these cases at least one unfavorable prognostic factor was present (stage > or = 3, elevated LDH, unfavorable histology, N-myc amplification, di- or tetraploidy). Neuroblastoma screening of infants aged more than six months seems to detect predominantly those tumors which are unlikely to regress spontaneously. The observation of one false negative case, however, demonstrates that neuroblastomas which become clinically manifest at a later date may remain undetected by early screening. Possible advantages of shifting screening to a later age and repeated screening are discussed.

Austria↗
PubMed1996

Bone marrow transplant indications for childhood leukemias: achieving a consensus. The EBMT Pediatric Diseases Working Party.

During the "2nd International Course on Bone Marrow Transplantation in Children" a multiple choice questionnaire on bone marrow transplant indications for children with acute leukemias was distributed with the aim of achieving a consensus. The answers obtained from the twenty representatives of fourteen European countries during the meeting were analyzed and assigned to one of the following groups: I. definitive indication: when more than 75% participants were in favour; II. acceptable indication: when 50% to 74% participants were in favour; III. requires further investigation: when 25% to 49% participants were in favour; IV. no indication: when less than 24% participants were in favour. In acute lymphoblastic leukemia the following circumstances were considered a definitive indication for allogeneic bone marrow transplant (BMT) from a matched sibling donor (MSD): infancy, "high risk" (HR) patients in 1st complete remission (CR1); CR2 patients after an early bone marrow relapse (defined as a relapse occurring up to six months after stopping therapy). Patients experiencing an early meningeal relapse and CR2 patients after a late relapse (defined as a relapse occurring later than six months after stopping therapy) were considered an acceptable indication. Further investigation was required in order to better define the role of BMT for patients experiencing an early isolated testicular relapse. If a MSD is not available, HR patients in CR1 and CR2 patients, after an early bone marrow relapse, were considered a definite indication for a matched unrelated donor (MUD). This latter group was considered an acceptable indication for a haploidentical BMT if a MUD was not available. Further investigation was required to better define the role of autologous bone marrow transplant (ABMT) for patients experiencing an early extramedullary relapse and for HR patients in CR1 all of whom lacked MSD's. In acute myeloblastic leukemia (AML), CR2 patients were considered a definitive indication and CR1 patients were considered an acceptable indication for BMT from a MSD. CR2 patients were considered a definitive indication for ABMT and CR1 patients an acceptable indication in cases lacking a MSD. AML was not considered an indication for MUD BMT.

Bone Marrow Transplantation↗