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E Mahlamäki

Publications and source records attributed to E Mahlamäki.

11 recordsLinked to original sources
PubMed1999

Acquired X-chromosome aneuploidy in children with acute lymphoblastic leukemia.

BACKGROUND: A cytogenetic study of 75 consecutive children with ALL revealed a normal karyotype, a low hyperdiploid karyotype (including 47-50 chromosomes), and a high hyperdiploid karyotype (including > 50 chromosomes) in 10, 12, and 33 patients, respectively. An acquired extra X-chromosome was detected at diagnosis by conventional cytogenetics in 29 (88%) of 33 children with a high hyperdiploid karyotype and in 4 (33%) of 12 children with a low hyperdiploid karyotype. X-chromosome aneuploidy was retrospectively studied by fluorescence in situ hybridization (FISH) in eight and 20 patients with a normal and a hyperdiploid karyotype, respectively. PROCEDURE: A classical cytogenetic study was performed according to standard methods. FISH with the centromeric probe specific to X-chromosome was used to study interphase cells of bone marrow or blood samples. RESULTS: An extra X-chromosome was found by FISH in all 13 patients with a high hyperdiploid or tetraploid, in 6 of 7 patients with a low hyperdiploid, and in none with a normal karyotype. Two children with a normal karyotype displayed monosomy X. Altogether, 57.3% of newly diagnosed children displayed X-chromosome aneuploidy. CONCLUSIONS: Out study indicates that X-chromosome aneuploidy may be the most common chromosome abnormality in childhood ALL. It can be detected in nearly all children with a high hyperdiploid karyotype and up to one-half of the patients with a low hyperdiploid karyotype. FISH with an X-chromosome centromeric probe is a rapid and simple tool to detect an abnormal clone at diagnosis in the majority of children with ALL and is useful in confirming remission in these patients.

Adolescent↗
PubMed1998

DNA copy number changes in childhood acute lymphoblastic leukemia.

BACKGROUND AND OBJECTIVE: Comparative genomic hybridization (CGH) allows the study of DNA copy number changes in a single hybridization from tumor DNA without any cell culture. Three reports of childhood acute lymphoblastic leukemia (ALL) studied by CGH have been published so far, with somewhat discrepant results. In the present study we performed CGH analysis on 36 patients with childhood ALL. The results were compared to those reported earlier on 157 cases. DESIGN AND METHODS: DNA was extracted from bone marrow specimens from 36 patients with childhood ALL. The tumor and reference DNAs were labeled with fluorescein-isothiocyanate conjugated dCTP and dUTP, and Texas red-conjugated dCTP and dUTP. The hybridizations were analyzed using the ISIS digital image analysis system. RESULTS: The most commonly gained chromosomes were X (42%), 4 (31%), 6 (31%), 10 (36%), 14 (28%) and 18 (33%), and the most common losses were at 9p22-pter (6%) and 12p13-pter (14%). INTERPRETATION AND CONCLUSIONS: The pattern of gains of DNA sequences was very similar in the four reports, but the 9p and 12p deletions were observed only in the present study and one previous report. Our review of the results of 193 patients studied so far shows that the success rate using CGH was close to 100%, whereas cytogenetic analysis failed to reveal any information in 21 patients (11%). Furthermore, in 69 (36%) out of 193 patients CGH gave additional information to the banding analysis. CGH should, therefore, be used to supplement standard cytogenetics in the analysis of childhood ALL patients.

Adolescent↗
PubMed1996

Detection of numerical chromosome abnormalities by FISH in childhood acute lymphoblastic leukemia.

Fluorescence in situ hybridization (FISH) was performed on interphase bone marrow cells to study numerical chromosome abnormalities in childhood acute lymphoblastic leukemia (ALL). Ten patients were selected for this study on the basis of having an extra chromosome 6 in the abnormal clone of the bone marrow at diagnosis. The numerical changes that were detected by FISH with a chromosome 6 specific alpha-satellite DNA probe correlated well with the cytogenetic and clinical data in all patients. Three hybridization signals were seen in 43.8--83.0% of interphase cells in the specimens with a hyperdiploid karyotype. The diagnostic bone marrow sample of the patient with a tetraploid karyotype revealed four signals in 67.0% of cells. Two signals were detected in the majority of the cells in the three nonleukemic control bone marrow samples (97.0--97.7%), assessing the cut-off value of about 1% for trisomy 6. This study demonstrates that FISH analysis is a useful and sensitive tool to screen for the presence of extra chromosomes in interphase cells and is important clinically for evaluating the achievement and maintenance of remission in hyperdiploid childhood ALL. However, to detect structural chromosome aberrations which carry important diagnostic and prognostic information, as seen in our patient with the translocation t(1;19) at diagnosis but not at relapse, conventional cytogenetic analysis should be performed both at diagnosis and at relapse.

Adolescent↗
PubMed1994

Cell lineage involvement of recurrent chromosomal abnormalities in hematologic neoplasms.

Analysis of most hematologic neoplasms indicates the involvement of one or more cell lineages in the bone marrow and/or the blood but rules out the involvement of all lineages in any one neoplasm. It is important to detect lineage involvement in order to clarify which stem cells are involved in leukemia, to predict prognosis, and to select appropriate treatment. Our aim was to study the cell lineage involvement of some of the recurrent chromosomal abnormalities seen in hematological neoplasms. The direct morphology-antibody-chromosomes (MAC) method was used. The deletion 20q in myeloproliferative diseases (MPD), the deletion of 5q and t(1;7) in myelodysplastic syndromes (MDS), and t(3;3) in acute myeloid leukemia subtype M7 (AML-M7) were seen in all or at least in two myeloid lineages. These were interpreted as stem cell abnormalities. Deletion 13q in MPD, t(8;21) in AML-M2 and t(15;17) in AML-M3 were seen in granulocytic lineages only; t(14;18) in non-Hodgkin's lymphoma and trisomy 12 as the sole abnormality in chronic lymphocytic leukemia (B-CLL) were seen only in immunoglobulin light chain clonal B cells; inversion 14 in T-CLL was seen only in T cells, whereas t(15;14) in acute lymphocytic leukemia with eosinophilia (ALL-EO) was seen in lymphoid stem cells but not in mature granulocytes or lymphocytes. Additional abnormalities (in addition to the Philadelphia chromosome) in chronic myeloid leukemia (CML) were seen in all myeloid cell lineages and also in mature granulocytes, B cells, and large granular lymphocytes. Abnormalities in Hodgkin's disease were restricted to CD30-positive Reed-Sternberg cells. Trisomy 8 and monosomy 7 are abnormalities that may be present in either stem cells or any of the single cell lineages.

Blast Crisis↗
PubMed1994

Multiple karyotypic abnormalities in three cases of small cell variant of T-cell prolymphocytic leukemia.

Cytogenetic, clinical, and laboratory findings of three patients with a small cell variant of T-cell prolymphocytic leukemia (T-PLL) are presented. Immunophenotypic studies of the morphologically typical small cell variant prolymphocytes showed a mature helper T-cell phenotype (CD4+CD8-) in one patient and a common thymocyte phenotype (CD4+ CD8+) in two other patients. The cytogenetic analysis revealed complex karyotypes with several structural aberrations in the peripheral blood lymphocytes of all three patients. In all cases chromosome 14 was affected with the breakpoint at 14q11. Inversion (14) and isochromosome 8q, often reported as an additional aberration in T-PLL, were detected in two of the patients. In two patients a translocation of the short arm of chromosome 12 was also seen. The T-cell receptor beta-chain gene showed a clonal rearrangement in all three patients, whereas no rearrangements were detected in the immunoglobulin genes. The survival of the patients ranged from 10 weeks to 48 months. The association between cytogenetic, clinical, and laboratory data is discussed.

Adult↗
PubMed1993

Analysis of phenotype and genotype of individual cells in neoplasms.

The authors describe a combination technique enabling detection of in situ hybridization (ISH) signals from chromosome-specific probes in interphase or mitotic cells that still retain the alkaline phosphatase antialkaline phosphatase (APAAP) or Sudan black B (SBB) staining reactions (simultaneous detection) or have been first classified morphologically and then by APAAP or SBB. The technique can be used on cell suspensions, in situ cultures and tissue sections. Examples from leukemias (chronic lymphocytic, myeloid, and acute myeloid leukemia) and solid tumors (chondromyxoid fibroma and glioblastoma) illustrate the potential of the technique in investigation of cancer tissue heterogeneity. In leukemias, it can be used to study cell lineage involvement, stem cells, and minimal residual disease, as well as to monitor therapy. In solid tumors, it can be used to identify neoplastic areas of tissue and to track the site of origin of neoplastic cells. Finally, it can be used to study the significance of chromosome abnormalities in carcinogenesis.

Adult↗
PubMed1988

Iron deficiency in adolescent female dancers.

The iron balance of 25 adolescent dancers and 23 control females of the same age were studied. The concentrations of fasting blood haemoglobin, serum iron, serum transferrin and serum ferritin were determined. Iron supplementation (ferrous sulphate corresponding to 100 mg of elemental iron per day) was instigated if body iron stores were low (serum ferritin less than 30 micrograms.l-1). Blood samples were drawn again after ten weeks. Low haemoglobin concentration (blood haemoglobin less than 125 g.l-1) was more prevalent among dancers than among control subjects. Reduced iron stores as well as completely absent iron stores (serum ferritin concentration less than 12 micrograms.l-1) were equally common in both groups (25% of the subjects). Iron supplementation reduced the number of anaemic girls from 16 to 4 and the highly significant difference in haemoglobin level between the treated and untreated groups disappeared. Ten weeks of iron therapy was not, however, long enough to increase iron stores.

Adolescent↗
PubMed1985

Exercise capacity in subjects with high oxygen affinity.

Exercise capacity and hemodynamic parameters were measured in ten patients with a previously unpublished variant of hemoglobin (Hb-Linköping) and in ten age- and sex-matched controls. Bicycle ergometer test was almost maximal and the indices of working capacity and cardiac tolerance were similar in patients and controls. The hemoglobin dissociation curve was shifted to the left at rest and after exercise the shift to right was half of the corresponding shift in controls. Lactate accumulation during exercise was similar in patients and controls, also the elimination rate seems identical, but requires further studies. Hydrogen ion production in the patients during exercise was more marked than in the controls. If this is a sign of altered energy metabolism remains to be ascertained in future studies. In acute short-term exercise the patients with abnormally high hemoglobin oxygen affinity seem to have similar tolerance and cardiovascular load. Aberrant metabolism and adaptation to relative hypoxia in spite of erythrocytosis may have long-term effects that require long-term follow-up of these patients.

Adult↗
PubMed1985

Adaptation of the May-Grünwald-Giemsa staining method for automated differential counting of blood leukocytes by a Hematrak analyzer.

The selection of exact pH (6.85/6.90) concentrations of the stains and staining times made it possible to use the May-Grünwald-Giemsa (MGG) staining method for smears studied with a Hematrak model 240 automated differential leucocyte counter. The differences between the smears stained by the method of Wright according to the recommendations of the manufacturer and the present MGG-modification resulted in non-significant differences in the recognition of various types of leucocytes. The differences between the manual method and those obtained by Hematrak for the MGG-stained samples with normal total leucocyte counts were nonsignificant with all types of leucocytes except basophils, which were underestimated by the instrument. The present staining procedure was adequate in studying of neutrophilias. When samples with lymphocytosis or with immature cells were examined, too few lymphocytes and immature cells and too many monocytes were obtained by the instrument, as compared to the manual method.

Automation↗