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C Fonatsch

Publications and source records attributed to C Fonatsch.

At least 37 records · Page 2Linked to original sources
PubMed2001

Cytogenetic risk groups in acute myeloblastic leukaemia differ greatly in their semi-solid colony growth.

We have analysed the results of semi-solid bone marrow cultures in 296 patients with de novo acute myeloblastic leukaemia (AML) and correlated them with the leukaemic karyotype. A favourable prognostic karyotype was found in 52 patients (group A, 18.3%), an intermediate karyotype in 163 patients (group B, 57.4%), and unfavourable cytogenetics were observed in 69 patients (group C, 24.3%). Median colony growth according to the three risk groups was 2 (range 0--344) in group A, 14.5 (range 0--5000) in group B and 50.0 (0--3000) in group C (A vs. B, P < 0.001; A vs. C, P < 0.001; B vs. C, P < 0.01). Among the patients treated with chemotherapy (n = 257), median colony growth was 10 (range 0-5000) in those who achieved complete remission (CR) compared with 56.5 (range 0-1000) in patients without remission (NR) (P = 0.002). The median colony growth of all patients [13/10(5) bone marrow mononuclear cells (BMMCs); range 0--5000] significantly discriminated between patients regarding survival (OS 11 vs. 7 months, P = 0.044). However, multiple Cox regression analysis revealed cytogenetic risk groups as the most important predictor for achieving CR, disease-free and overall survival, with colony growth adding no additional prognostic information. In 64 patients, colony growth was also investigated without the addition of exogenous cytokines. Interestingly, none of the patients with a favourable karyotype exhibited autonomous growth, whereas 50% with an intermediate and 73% of patients with an unfavourable karyotype displayed either partial or full autonomous growth in vitro (P = 0.0004). Our data suggest that the growth potential of the leukaemic clone seems to be critically influenced by the molecular changes emerging from chromosomal abnormalities.

Adolescent↗
PubMed2001

The leukaemia-associated transcription factors EVI-1 and MDS1/EVI1 repress transcription and interact with histone deacetylase.

EVI-1 and its variant form, MDS1/EVI1, have been reported to act in an antagonistic manner and be differentially regulated in samples from patients with acute myeloid leukaemia and rearrangements of the long arm of chromosome 3. Here, we show that both EVI-1 and MDS1/EVI1 can repress transcription from a reporter construct containing EVI-1 binding sites and interact with histone deacetylase in mammalian cells. This interaction can be recapitulated in vitro and is mediated by a previously characterized transcription repression domain, whose activity is alleviated by the histone deacetylase inhibitor trichostatin A.

Animals↗
PubMed2000

Variant intra philadelphia translocation with rearrangement of BCR-ABL and ABL-BCR within the same chromosome in a patient with cALL.

A unique variant Philadelphia translocation accompanied by the loss of the short arm of chromosome 9 in a 32-year-old female with common acute lymphoblastic leukemia (cALL) is described. Furthermore, supernumerary chromosome 8 material was found as an insertion into the long arm of chromosome 2 and/or as ring chromosomes in addition to two normal chromosomes 8. The chromosomal abnormalities were identified by combined conventional chromosome banding analysis and fluorescence in situ hybridization (FISH). The BCR-ABL rearrangement was confirmed by FISH and reverse transcriptase-polymerase chain reaction (RT-PCR) studies. Possible mechanisms leading to this variant intra Philadelphia translocation are discussed. The aberrations found have prognostic implications, because 9p anomalies confer an adverse effect to the already poor prognosis of Philadelphia-positive ALL.

Adult↗
PubMed2000

Familial cryptic translocation with del 4q34-->qter and dup 12pter-->p13 in sibs with tracheal stenosis: clinical, classical and molecular cytogenetic studies and CGH analyses from archival placental tissues evidencing tertiary trisomy 4 in one abortion specimen.

We report on two retarded half-sibs of different sex and seemingly normal karyotype who had the same syndrome of minor anomalies, heart defect and a distal tracheal stenosis, and who shared a healthy mother. These findings raised suspicions of a cryptic chromosome translocation. A translocation t(4;12)(q34;p13), balanced in the mother and unbalanced in the sibs with loss of terminal 4q and gain of terminal 12p regions, was verified by FISH using whole chromosome painting, subtelomeric and YAC probes. Clinical features could be explained by partial monosomy 4q and partial trisomy 12p. Tracheal stenosis was interpreted as a consequence of the same developmental disturbance leading to esophageal atresia and tracheo-esophageal fistula. It was attributed to the 4q deletion in which esophageal atresia as also respiratory difficulties and airway obstructions had been described. Paraffin-embedded placental tissues were available from three of the five abortions of the mother allowing DNA extraction and comparative genome hybridization (CGH). Two of the abortion specimens had the same der(4)t(4;12)(q34;p13) unbalanced translocation as identified in the sibs. In the third abortion specimen, suspicious of triploidy because of partial hydatidiform mole, CGH uncovered a tertiary trisomy 4 resulting from a 3:1 segregation of the translocation chromosomes and their homologs during maternal meiosis I. Differences in CGH results using DNA generated directly or after DOP-PCR were explained by DNA fragmentation in paraffin-embedded tissues and unequal amplification. Am. J. Med. Genet. 94:271-280, 2000.

Adult↗
PubMed2000

Transcription factor GATA-2 gene is located near 3q21 breakpoints in myeloid leukemia.

Rearrangements affecting chromosome band 3q21 are observed in a subgroup of patients with acute myeloid leukemia (AML) or myelodysplastic syndrome (MDS). However, little is known about the molecular consequences of such aberrations. We therefore established a PAC contig in the 3q21 breakpoint region and identified potential protein coding sequences by exon trapping. One of the exons isolated was from the human GATA-2 gene, which we showed to be transcribed from telomere to centromere. The majority of 3q21 breakpoints are located telomeric to the transcribed portion of this gene in a region that in mice appears to be necessary for proper promoter function. Results of GATA-2 expression analyses in leukemic cell lines as well as primary patient samples are compatible with the hypothesis that 3q21 aberrations contribute to leukemogenesis through deregulation of the hematopoietic transcription factor GATA-2.

Acute Disease↗
PubMed2000

Three different premature stop codons lead to skipping of exon 7 in neurofibromatosis type I patients.

Neurofibromatosis type 1 (NF1) is an autosomal dominant genetic disorder affecting one in 3,500 individuals. The mutation rate in the NF1 gene is one of the highest known for human genes. Compared to other methods, the protein truncation test (PTT) provides improved efficiency in detecting NF1 mutations which are dispersed throughout the gene which spans 350 kilobases of genomic DNA. We have applied the PTT and subsequent sequence analysis of cloned cDNA to identify mutations in NF1 patients. We report here the identification of two novel (W336X and Q315X), and one recurrent (R304X) mutation located in exon 7 and show that all three premature termination codons lead to skipping of exon 7 in a proportion of the transcripts derived from the mutated allele. Possible mutation-induced alterations of the RNA secondary structure and their impact on skipping of exon 7 of the NF1 gene are explored and discussed.

Base Sequence↗
PubMed2000

Low curative potential of bone marrow transplantation for highly aggressive acute myelogenous leukemia with inversioin inv (3)(q21q26) or homologous translocation t(3;3) (q21;q26).

Structural rearrangements of the long arm of chromosome 3 involving bands 3q21 and 3q26 and leading either to a paracentric inversion inv (3)(q21q26) or a translocation between both homologous chromosomes--t(3;3)(q21q26)-- have been reported in patients with acute myelogenous leukemia (AML), myelodysplastic syndromes, myeloproliferative disorders, and chronic myelogenous leukemia in blast crisis. We describe three patients with de novo AML with these structural abnormalities who received multiple courses of conventional chemotherapy followed by unrelated donor (n=2) and autologous (n = 1) bone marrow transplantation (BMT). All three patients had early relapse: patients 1 and 2 had relapse 69 days and 306 days after BMT, respectively, and patient 3 immediately after autologous BMT. Despite further chemotherapy, they died without achieving another remission. These findings, together with other recorded similar cases, show that AML with structural abnormalities of the long arm of chromosome 3 as described has an extremely poor prognosis even with the most potent anti-leukemic treatment modalities.

Adult↗
PubMed2000

Excellent disease eradication by myeloablative therapy and stem-cell transplantation in patients with acute myelogenous leukemia.

Between February 1982 and 1999, 118 consecutive patients (65 male, 53 female) with acute myelogenous leukemia (AML), with a median age of 35 years (range 17-56 years), received stem-cell grafts from a human leukocyte antigen-identical sibling (n = 71), one-antigen-mismatched family member (n=2), matched unrelated donor (n=15), one-antigen-mismatched unrelated donor (n = 4) or an autologous (n = 26) graft. At the time of transplant, 56 patients were in the first complete remission (CR), 27 in the second CR, 6 in untreated relapse, 17 in primary refractory, and 12 in refractory relapse. The French-American-British classification (FAB) subtypes were as follows: M1 (n=25), M2 (n=28), M3 (n=11), M4 (n =32), M5 (n=16), M6 (n = 6). For conditioning, most patients underwent total body irradiation-containing regimens. As of 28 February, 1999, probability of leukemia-free survival (LFS) is 58% for patients after related and 45% after unrelated stem-cell transplantation (SCT). The probability of LFS is 70% for patients given allogeneic transplants in the first CR compared with 33% for those beyond the first CR at SCT. In autologous stem-cell graft recipients, the probability of LFS is 37%. Transplant-related mortality was 28% after related, 20% after unrelated, and 4% after autologous SCT. Probability of relapse for patients given related-donor stem-cell grafts in the first CR and beyond the first CR is 30% and 67%, 55% after unrelated and 63% after autologous stem-cell grafting. Thus, myeloablative therapy followed by allogeneic stem-cell infusion has a high curative potential for patients with AML in remission and offers substantial benefits to patients in advanced disease.

Adolescent↗
PubMed2000

Illegitimate splicing of the NF1 gene in healthy individuals mimics mutation-induced splicing alterations in NF1 patients.

Neurofibromatosis type 1 (NF1) is a common inherited disease affecting one in 3,500 individuals. The mutation rate in the NF1 gene is one of the highest known for human genes. Compared to other methods, the protein truncation test (PTT) and subsequent sequence analysis of cloned cDNA provides improved efficiency in detecting NF1 mutations that are dispersed throughout the gene spanning 350 kb of genomic DNA. Sequencing of cDNA of patients affected with NF1 mutations revealed multiple splicing errors. Since similar missplicings were also found in "aged" blood of healthy individuals, they are most likely attributable to a general decrease in splice site selection in aged blood. We show that restoring viability of lymphocytes before RNA extraction by cultivation and PHA stimulation diminishes aberrant splicing in aged blood and is thus useful to circumvent splicing alterations which are frequently compromising mutation detection in patient samples and mimic mutation-induced alterations of mRNA.

Cellular Senescence↗
PubMed2000

Reciprocal translocation (3;5)(q26;q22) and possible BCHE gene involvement in an unusual myelogenous disorder with both myeloproliferative and dysplastic features.

We report on a 77-year-old male patient who presented with an unusual myelogenous disorder exhibiting both myeloproliferative and dysplastic features. The patient suffered from leukocytosis, eosinophilia, basophilia, transfusion dependent anemia, and rapidly progressing thrombocytopenia. Classical chromosome analysis and fluorescence in situ hybridization (FISH) revealed a reciprocal t(3;5)(q26;q22). Using yeast artificial chromosome (YAC) probes, the breakpoint on chromosome 3 was localized to the butyrylcholinesterase (BCHE) gene (3q26.1-q26.2). This gene has recently been implicated in the regulation of myeloid cells. Whether the BCHE gene was also involved in the deregulation of myelopoiesis, causing the unusual clinical picture in this case, remains unknown.

Aged↗
PubMed2000

Extramedullary T cell lymphoblastic transformation of chronic myeloid leukaemia successfully treated with matched unrelated donor bone marrow transplantation.

Chronic myeloid leukaemia (CML) inevitably terminates in blast crisis (BC) which is of myeloid phenotype in approximately two-thirds and B-lymphoid in one-third of patients. T cell BC is rare and associated with poor prognosis. We describe the case of a 48-year-old woman with extramedullary T cell lymphoblastic transformation. After treatment with combination chemotherapy she achieved a second chronic phase and underwent an allogeneic BMT from an HLA-matched unrelated donor. At 30 months follow-up she is still in complete molecular remission and in good clinical condition. We conclude that unrelated donor BMT should be considered as a therapeutic option for patients with extramedullary BC.

Blast Crisis↗
PubMed2000

Molecular analysis of the CALM/AF10 fusion: identical rearrangements in acute myeloid leukemia, acute lymphoblastic leukemia and malignant lymphoma patients.

The recurring translocation t(10;11)(p13;q14) which is found in acute myeloid leukemia (AML) and in acute lymphoblastic leukemia (ALL) results in the fusion of the putative transcription factor AF10 to CALM encoding a clathrin assembly protein. Previous studies using mainly fluorescence in situ hybridization (FISH) analysis have shown that the CALM/AF10 rearrangement is found in immature acute myeloid leukemia (AML) of subtype M0 and M1 and in T cell ALL. In this study we analyzed the CALM/AF10 and AF10/CALM fusion mRNAs in a series of three patients with AML, one patient with T-ALL and two patients with precusor T lymphoblastic lymphoma. In all six patients the breakpoint in CALM is at the 3' end of the coding region (nt1926/1927 or nt 2091/2092). Three breakpoints could be identified in AF10 (nt 588/589, nt 882/883 and nt 978/979). These data demonstrate that the CALM/AF10 fusions found in patients differ only slightly with respect to the portion of AF10 present and that there is no obvious difference between the fusions found in AML patients compared to those found in patients with lymphoid malignancies. Leukemia (2000) 14, 93-99.

Amino Acid Sequence↗
PubMed2000

Drug resistance factors in acute myeloid leukemia: a comparative analysis.

To compare the clinical relevance of drug resistance factors in de novo acute myeloid leukemia (AML), we determined their relationship to both response to induction chemotherapy and survival of the patients in univariate as well as multivariate analyses. The drug resistance factors immunocytochemically studied in 111 patients at the time of diagnosis included the lung resistance protein (LRP), P-glycoprotein (P-gp), multidrug resistance protein (MRP1) and bcl-2. In the univariate analyses, age (P = 0.005), karyotype (P = 0.03), LRP (P = 0.003), P-gp (P = 0.02) and bcl-2 (P = 0.03) predicted for response to induction chemotherapy, whereas MRP1 had no predictive value. Age (P = 0.05), karyotype (P = 0.05) and LRP (P = 0.03) retained their predictive value in the multivariate logistic regression analyses. With regard to overall survival, age (P = 0. 008), karyotype (P = 0.006), LRP (P = 0.001) and P-gp (P = 0.01) were of prognostic value in the univariate Cox regression analyses but only age (P = 0.01), karyotype (P = 0.02) and LRP (P = 0.01) retained their prognostic significance in the multivariate analyses. A risk score based on the number of independent prognostic factors allowed division of patients into four groups with different outcome. In these groups, the complete remission rates were 93%, 75%, 47% and 33%, respectively, and median overall survival was 2.4, 1.2, 0.6 and 0.2 years, respectively. Thus, several drug resistance factors did predict outcome in the univariate analyses but LRP was the only drug resistance factor with independent predictive and prognostic significance. The proposed risk score might be useful for risk-adapted treatment in the future. Leukemia (2000) 14, 68-76.

Acute Disease↗
PubMed2000

Double induction strategy including high dose cytarabine in combination with all-trans retinoic acid: effects in patients with newly diagnosed acute promyelocytic leukemia. German AML Cooperative Group.

A prospective multicenter study was performed to investigate the clinical and molecular results of intensified double induction therapy including high-dose cytarabine (ara-C) in combination with ATRA in newly diagnosed acute promyelocytic leukemia (APL), followed by consolidation and 3 years maintenance therapy. Fifty-one patients, diagnosed and monitored from December 1994 to June 1999, were evaluated. The median age was 43 (16-60) years. The morphologic diagnosis was M3 in 40 (78%) and M3v in 11 (22%) patients. In 15 (30%) patients the initial white blood cell counts were > or =5 x 10(9)/l. The cytogenetic or molecular proof of the translocation t(15;17) was a mandatory prerequisite for eligibility. The diagnosis was confirmed by karyotyping in 46 and by RT-PCR of the PML/RARalpha transcript in 45 cases. The rate of complete hematological remission was 92% and the early death rate 8%. Monitoring of minimal residual disease by RT-PCR of PML/RARalpha (sensitivity 10(-4)) showed negativity in 29 of 32 (91%) evaluable cases after induction, in 23 of 25 (92%) after consolidation, and in 27 of 30 (90%) during maintenance, after a median time of 2, 4 and of 18 months after diagnosis, respectively. After a median follow-up of 27 months, the estimated actuarial 2 years overall and event-free survival were both 88% (79, 97), and the 2 years relapse-free survival 96% (90, 100). The high antileukemic efficacy of this treatment strategy is demonstrated by a rapid and extensive reduction of the malignant clone and by a low relapse rate. The results suggest that the intensity of the induction chemotherapy combined with ATRA is one of the factors which may have a critical influence on the outcome of APL. A randomized trial should assess the value of an induction therapy including ATRA and high-dose ara-C in comparison to standard-dose ara-C.

Adolescent↗
PubMed2000

Prognosis of patients with a second relapse of acute myeloid leukemia.

Recurrence of the disease is the major problem in the treatment of acute myeloid leukemia (AML). The majority of patients who achieve a second remission will ultimately relapse. In this retrospective single-center study, we have analyzed the outcome of patients with a second relapse and tried to define the prognostic factors in intensively treated patients. Of 534 patients with AML, 62 had a second relapse. Thirty-three received further intensive chemotherapy (CT). Eighteen patients (55%) achieved a third complete remission (CR). The early death (ED) rate was only 9%. The overall survival (OS) of treated vs untreated patients was 6.9 vs 1.3 months, respectively (P = 0.01). The major selection criteria for a third CT were a favourable (t(15;17),t(8;21),inv(16)) or normal karyotype, long (>11 months) second CR (P < or = 0.005) and no previous bone marrow transplantation (BMT)(P < 0.01). Favorable or normal karyotype, second CR >11 months, as well as no previous BMT (P < 0.01) were associated with the achievement of a third CR. Favorable (P < 0.005) or normal karyotype (P < 0.01), as well as a second CR >11 months (P < 0.005) were associated with prolonged survival after CT. The median OS for patients receiving CT with favorable or normal cytogenetics, a second CR > 11 months, but no previous BMT was 26.5 months. Five patients with favorable or normal karyotype achieved a fourth or fifth remission. We conclude that intensive CT is associated with a survival benefit and good quality of life if patients are properly selected.

Acute Disease↗
PubMed2000

Mapping of leukaemia-associated breakpoints in chromosome band 3q21 using a newly established PAC contig.

Chromosome aberrations affecting band 3q21 are associated with a particularly poor prognosis in patients with acute myeloid leukaemia. To facilitate the molecular characterization of such rearrangements, we established a PAC contig covering the relevant genomic region. Using these PACs as probes in fluorescence in situ hybridization (FISH) experiments, we showed that a number of 3q21 breakpoints in patient samples map to a previously defined 'breakpoint cluster region'. Others, however, are located at varying distances centromeric of it. These results have important implications in the search for genes affected by 3q21 rearrangements.

Acute Disease↗
PubMed2000

High concordance of karyotype analysis and RT-PCR for CBF beta/MYH11 in unselected patients with acute myeloid leukemia. A single center study.

Identification of the inversion 16 in patients with acute myeloid leukemia (AML) is of great practical value since these patients have a relatively favorable prognosis, especially when treated with high-dose cytarabine. We compared the results of cytogenetic analysis and reverse transcriptase-polymerase chain reaction (RT-PCR) for core binding factor (CBF) beta/myosin heavy chain (MYH11) in 241 unselected cases of AML. In contrast with other studies, we found a high concordance between these 2 methods. Eighteen of 241 patients showed a cytogenetic anomaly of the chromosome 16. We detected the fusion transcript by RT-PCR in all 18 cases and in 2 additional patients with AML without any cytogenetic anomaly of chromosome 16. One patient had a normal diploid karyotype, and the second patient showed a trisomy 22 in karyotype analysis, which often is associated with inv(16). Only 8 of 20 CBF beta/MYH11-positive patients had M4Eo morphologic features. The much higher discrepancy between cytogenetic analysis and RT-PCR in other studies, especially in AMLs other than M4Eo, possibly indicates the necessity for PCR screening regardless of the French-American-British classification.

Acute Disease↗