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K Michalová

Publications and source records attributed to K Michalová.

At least 19 recordsLinked to original sources

Immunological profiles of patients with chronic myeloid leukaemia. I. State before the start of treatment.

In view of the increasing interest in the immunotherapy of CML it seems highly desirable to broaden the present knowledge on the immune reactivity of CML patients. A group of 24 patients and 24 healthy controls were studied for the total of 15 immunological parameters, including the prevalence of antibodies against human herpesviruses and papillomaviruses. To clearly discriminate between changes associated with the disease and those induced by the therapy, all patients were enrolled prior to the start of any anti-leukaemic therapy. Statistically significant differences between patients and controls were found in the levels of IgA, C4 component of complement, CRP and IL-6, the production of Th1 cytokines in stimulated CD3 cells and the E. coli stimulatory index. The analysis of the interrelationship between the results obtained in the individual patients presented some unexpected findings, such as the lack of correlation between the CRP and IL-6 levels. It will be the purpose of a follow-up to determine whether and how the immune status of the patients prior to the treatment correlates with their response to therapy and how the individual immunological profiles change in the course of the disease. These observations will be utilized in the future immunotherapeutic studies to constitute the vaccine- and placebo-treated groups.

Adult↗

NORs and their transcription competence during the cell cycle.

In human cells ribosomal genes are organized as clusters, NORs, situated on the short arms of acrocentric chromosomes. It was found that essential components of the RNA polymerase I transcription machinery, including UBF, can be detected on some NORs, termed "competent" NORs, during mitosis. The competent NORs are believed to be transcriptionally active during interphase. However, since individual NORs were not observed in the cell nucleus, their interphase status remains unclear. To address this problem, we detected the competent NORs by two commonly used methods, UBF immunofluorescence and silver staining, and combined them with FISH for visualization of rDNA and/or specific chromosomes. We found that the numbers of competent NORs on specific chromosomes were largely conserved in the subsequent cell cycles, with certain NOR-bearing homologues displaying a very stable pattern of competence. Importantly, those and only those NORs that were loaded with UBF incorporated bromo-uridine in metaphase after stimulation with roscovitine and in telophase, suggesting that competent and only competent NORs contain ribosomal genes transcriptionally active during interphase. Applying premature chromosome condensation with calyculin A, we visualized individual NORs in interphase cells, and found the same pattern of competence as observed in the mitotic chromosomes.

Cell Cycle↗

Molecular cytogenetic stratification of recurrent oligodendrogliomas: utility of interphase fluorescence in situ hybridization (I-FISH).

In oligodendroglial brain tumours, losses of chromosomal material of the short arm of chromosome 1 and long arm of chromosome 19 have been shown to predict responsiveness to chemotherapy and prolonged patients' survival. Therefore, the correct diagnosis of these genetic alterations in tumours of oligodendroglial origin is particularly important. To detect deletions of 1p36 and/or 19q13.3 in oligodendroglial cells we used dual-colour I-FISH with locus-specific DNA probes. I-FISH was performed on isolated whole cell nuclei, prepared from fresh non-fixed tumour tissue samples resuspended in media and processed using a standard cytogenetic procedure, thus bypassing the problem of nuclear truncation. We examined 16 patients with histologically proved oligodendrogliomas (5x oligodendroglioma, 9x anaplastic oligodendroglioma, 2x anaplastic oligoastrocytoma). The results of molecular cytogenetic analyses were correlated with morphological and clinical findings. Molecular cytogenetic analyses were successful in 15 patients and, due to a non-adequate tissue specimen, were uninformative in one patient only. Combined deletions 1p36/19q13 were proved in 13 patients. However, in six of them additional genetic alterations typical for high-grade astrocytoma were found, which could have negative influence on the prognosis. One patient had isolated deletion of 1p36 and another had a normal genetic pattern without any chromosomal alterations. In summary, I-FISH on isolated cell nuclei is a powerful tool for detecting chromosomal aberrations in tumour cells. A systematic molecular cytogenetic analysis may advance diagnosis, prognostic stratification, and targeted treatment of patients with brain tumours.

Adult↗

Prognostic relevance of the FAB morphological criteria in chronic lymphocytic leukemia: correlations with IgVH gene mutational status and other prognostic markers.

Morphological examination is the routine first step in the diagnosis of hematological malignancies, including chronic lymphocytic leukemia (CLL). Atypical cell morphology according to the FAB criteria is known to herald disease progression. Several years ago, it was proposed that FAB morphology at diagnosis had a considerable prognostic impact. However, this proposal has not been widely adopted in practice. Thus we questioned the prognostic value of the morphological examination, which was performed retrospectively in 88 patients out of our 110 institutional registry patients (70 males and 40 females, median age 57 yrs) with CLL at diagnosis. We related the results to the more modern prognostic markers. Atypical FAB morphology was shown to correlate with IgVH gene mutation status, trisomy of chromosome 12 and deletion of 17p detected either by conventional G-banding or by fluorescence in situ hybridization (FISH) analysis. The correlation of FAB morphology with CD38 antigen expression or with the histopathological pattern of bone marrow infiltration was not significant. Overall survival (OS) data were available for 84 morphologically examined patients. The patients with atypical morphology (64 patients) had a significantly shorter OS (103 months) than the 20 patients presenting with typical CLL morphology (237 months; p=0.03). Only the mutation status of IgVH genes correlated more closely with OS (p=0.002). Of note, there was no leukemia-related death within "unmutated" cases who had typical FAB morphology (p=0.14), and vice versa, the mutation status had a significant prognostic impact within the morphologically atypical cases (p=0.01). Thus FAB morphology and the mutation status may yield complementary prognostic information. OS was affected both by the presence of cytogenetic aberrations (p=0.03) - most adversely by deletions of 17p and 11q, and by CD38 expression (p=0.003). We conclude that careful examination of peripheral blood smears according to FAB is a simple, cheap and valuable tool in the first-line assessment of prognosis of CLL patients and should not be overlooked even in 3rd millennium when more sophisticated prognostic markers are at hand. This ought to be confirmed in larger prospective studies with multivariate analysis of data.

ADP-ribosyl Cyclase 1↗

[Molecular cytogenetics in diagnostics of malignant diseases].

Malignant cell transformation can be defined as series of progressive genetic events which are happening in one cell clone in limited number of specific genes. These genes could be oncogenes and/or tumor suppressor genes (antioncogenes, recessive oncogenes). Each change regardless if it is associated with initiation or progression of cancer can be related to a chromosomal rearrangement. If the aberration is above the limit of the light microscope sensitivity, it should be detected by classical cytogenetic techniques. Therefore it was hypothesized that the molecular characteristics of chromosomal rearrangements will lead to identification of genes with pivotal role in cancerogenesis. And indeed, genes important for origin of tumors were identified in recurrent chromosomal breakpoints. Until now, more than 1800 breakpoints were identified. Oncocytogenetics has remarkably developed after the introduction of molecular methods with higher sensitivity (100 kb). We present a short review of molecular cytogenetic methods with a survey of specific recurrent translocations and deletions of chromosomes in several malignancies and their prognostic value is given.

Chromosome Aberrations↗

[Radionuclide screening in endocrinology].

The study provides an overview of current possibilities for use of nuclear medicine methods in endocrine diagnostics and therapy. Somatostatin receptor analogue is applied to the hypothalamus-hypophysis system, analogue medium to is used, in thyroid diagnostics, besides the determined tumour markers, tenchecium-labelled MIBI radioiodine 131 is used to determine and monitor carcinomas. Recently, rhTSH before starting thyroid carcinoma treatment is used. Neuroendocrinology tumours are suspected through 123I-MIBG; when scintigraphy is positive, therapeutic 131I-MIBG can be administrated. In diagnostics of the pituitary gland, two-step scintigraphy of MIBI is preferably used rather than subtraction methods. In patients with late or not significantly differenciated malignant tumours, positrone emission tomography is of benefit.

Humans↗

[Consolidation of therapy of acute myeloid leukemia with the AML-BFM 93 protocol in children in the Czech Republic].

BACKGROUND: Acute myeloid leukemia (AML) in children is rare. Although more resistant to chemotherapy than acute lymphoblastic leukemia, its responsiveness and survival rates have considerably improved during the last 15 years by virtue of intensification of chemotherapy and due to the better supportive care. Relapses still remain the main cause of treatment failure. Management of children with AML was unified in the Czech Republic in 1993 according to AML-BFM 93 Study protocol. METHODS AND RESULTS: Treatment results were evaluated in 61 patients, of whom 45 (73.8%) achieved complete remission. Five-year event-free-survival (EFS) was found in 42.3%, and overall survival was 45.3%. Prognosis of the standard-risk patients was significantly better than in the high-risk group (EFS 62.5% vs. 29.7%, p = 0.03). The most important prognostic factor was the early treatment response. Compared to chemotherapy, allogeneic stem-cell transplantation did not significantly improve the outcome of high-risk patients. CONCLUSIONS: Treatment results of children with AML in the Czech Republic are comparable to those achieved by leading leukemia study groups in the world. The aim of the next study is to increase the complete-remission rate by reducing early deaths.

Acute Disease↗

[Relation between diabetes compensation, albuminuria and biochemical parameters and the results of stress myocardial SPECT in asymptomatic type 2 diabetics].

The patients with diabetes mellitus and another risk factors have significantly higher risk to suffer from ischemic heart disease. Myocardial stress SPECT represents the examination which correlates very well with the results of selective coronary angiography even in asymptomatic diabetic patients. The aim of our study was to evaluate the relation of SPECT result to diabetes compensation, presence of micro/macroalbuminuria, blood level of fibrinogen, CRP, homocysteine and uric acid. Out of 126 diabetic 2. type abnormal SPECT has been found in 33 (26%). Fasting blood sugar (9.3 +/- 1.4 mmol/l in patients with abnormal SPECT vs. 9.7 +/- 1.9 mmol/l in the other diabetics, n.s.) and HbA1c (7.5 +/- 1.3% vs. 7.5 +/- 1.3%, n.s.) are not significantly different in the patients with abnormal SPECT to the other diabetics without this finding. Micro/macroalbuminuria was significantly more frequently seen in patients with abnormal SPECT (60% of patients with abnormal SPECT and 29% in the rest of diabetics, p = 0.01). Fibrinogen was significantly more elevated in diabetics with abnormal SPECT (3.76 +/- 0.5 g/l in the group with abnormal SPECT vs. 3.23 +/- 0.43 g/l, p = 0.0003). In the diabetics with abnormal SPECT we have found significantly higher CRP (3.84 +/- 1.51 mg/l vs. 2.79 +/- 1.13 mg/l, p = 0.024) and homocysteine (13.78 +/- 3.26 micromol/l vs. 10.98 +/- 2.33 micromol/l, p = 0.006). Uric acid level was not significantly different in the group of diabetics with abnormal SPECT to the rest of the patients (361 +/- 64 micromol/l in abnormal SPECT vs. 353 +/- 51 micromol/l, n.s.). When we analyse our results we have found that abnormal SPECT is rarely discovered in the asymptomatic 2nd type diabetics with the combination of negative micro/macroalbuminuria and fibrinogen level below 3.5 g/l.

Albuminuria↗

[Lymphocyte immunophenotyping and cytogenetics for more precise prognosis in patients with type B chronic lymphatic leukemia].

BACKGROUND: The B-chronic lymphocytic leukemia (B-CLL) has highly variable prognosis. Possibility of more relevant prognosis has a great impact for the beginning and mode of therapy. METHODS AND RESULTS: One hundred patients diagnosed as having B-CLL were included into the study. Beside usual examinations necessary to establish the diagnosis, cytogenetic examination for the detection of deletion 13q14, 17p13, 11q23 and trisomy 12 and immunophenotyping was done. The mean age of the patients was 58.2 years, there were 62 men and 38 women. 91 evaluated patients were divided into two groups--those with the steady disease (55 pts) and those with progressive disease (36 pts). No relation between the number of cytogenetic abnormalities and the Rai stage of the disease was found. We identified a relation between the bone marrow infiltration pattern (diffuse) and the number of cytogenetic abnormalities and the del 13q14 (p.05). Using the immunophenotyping of the lymphocytes we found a relation between the expression of CD38 and CD11c and the disease progression (p < 0.05). Neither of the method (FISH and immunophenotyping) revealed differences between results from bone marrow samples and those from peripheral blood. CONCLUSIONS: Though the cytogenetic (FISH) and immunophenotype evaluation at the time of diagnosis did not improve the ability to define better the clinical course of the B-CLL, we suggest to use both methods routinely as an important tool to identify patients who would develop the progressive disease.

Adult↗

[Long-term results of the UHKT-911 study of adult patients under 65 years of age with de novo acute myeloid leukemias without favorable karyotypes].

Between February 1991 and April 1994 induction chemotherapy of 32 adult consecutive patients under 65 years with de novo acute myeloid leukemias (AML) was started in the study UHKT-911. They were 19 women and 13 men, aged 18-63 (median 44) years. Their AML were classified according to the FAB classification: 3 M0, 3 M1, 9 M2, 14 M4, 3 M5. Induction chemotherapy consisted of 1-2 cycles with 3-4 doses of daunorubicin (DNR) 45 mg/m2/d i.v. and 14 doses of cytosine arabinoside (Ara-C) 200 mg/m2 per 3-h infusion every 12 hours. After the treatment patients, not being in complete remission, got the HD cycle with 10 high-doses of Ara-C 2000 mg/m2 per 3-h infusion every 12 hours i.v. and DNR 45 mg/m2/d i.v. on days 4 and 5, then the EMi cycle composed of etoposide 100 mg/m2/d i.v. for 5 days and mitozantrone 10-12 mg/m2/d i.v. on days 1, 3 and 5. Complete remission (CR) was achieved in 25 of 32 (78%) patients after 1-3 cycles. Five patients died between days 5 and 24 of treatment of infections, two patients were resistant to 4 cycles of induction therapy and survived 8.4 and 13.5 months. Three patients chose allogeneic bone marrow transplantation in their 1st CR from their relatives. Two of them have been living in CR for 115 a 110 months since diagnosis, the third died of sepsis on the day 52 after transplantation. Two patients in CR died of infections after their 2nd. consolidation cycle. Twenty patients in CR completed 2-4 consolidation cycles (1-3 HD, 1 EMi). Median of their CR duration was 17.8 (2-117) months. Relapse appeared in 12 cases after 4.4-34.8 (median 12.5) months, 8 patients (6 women and 2 men, aged 29-63 years) have remained longer than 5 years in their 1st. CR. Cytogenetic examination of their bone marrow showed a normal karyotype in 4 cases, 1x 46,XX,del(1)(p32p34), 1x 46,XX,16p+, 1x 47,XX,+mar, 1x 46,XX,del(5)(q22q33). After 62 months in CR a pancytopenia with dysplastic bone marrow changes developed in one of them, probably a secondary myelodysplastic syndrome, lasting for further 33 months. Event-free survival at 5 years was 27.5% (8/29 patients), significantly better (p = 0.046) against 7.5% (3/40) patients treated without HD cycles in the years 1982-1987. The same difference was observed in 7.5-year overall survival (p = 0.036) between the two studies, when 3 of 6 patients 60-64 years old remain in their 1. CR.

Acute Disease↗

[Myelodysplastic syndrome--classification, prognosis and therapy].

BACKGROUND: The impact of classification, prognostic factors and treatment on survival and rate of leukemic transformation was analysed in 197 patients with primary myelodysplastic syndrome (MDS) treated in the Institute of Hematology and Blood Transfusion in the years 1980-2000. METHODS AND RESULTS: The patients were classified according to the FAB criteria and divided into risk groups according to the International Prognostic Scoring System (IPSS). A separate evaluation of 34 patients who underwent stem cell transplantation and of 163 of those not transplanted was performed. Median survival of not transplanted patients with RAEB (10.0 months) and RAEB-T (12.0 months) was significantly shorter than survival of RA (62.4 months) and RARS (48.1 months, P < 0.001) patients as well as survival of patients included in intermediate II. (13.8 months) and high (10.8 months) risk subgroups when compared to those with low (74.9 months) and intermediate I. risk (56.0 months, P < 0.001). A similar difference was observed in percentage of patients evolving towards acute leukemia and in estimated 3 years survival (EFS). EFS of RA patients was 57% in contrast to 4% in RAEB-T group (P < 0.001) in the same way, EFS in low risk subgroup was 79% vs. 3% in high risk patients (P < 0.001). Chemotherapy alone did not significantly affect median survival of patients with advanced MDS when compared with supportive care. On the contrary, median survival of transplanted patients with RAEB and RAEB-T was 38.4 months in comparison to 11.5 months in those not transplanted (P < 0.001) and 36.8 months vs. 12.0 months in transplanted and not transplanted patients with intermediate II. and high risk (P = 0.05). The difference in survival between transplanted and not transplanted patients with RA and in patients in low and intermediate I. risk subgroups was not statistically significant. CONCLUSIONS: We confirmed an adverse effect of excess of blasts on prognosis of patients with primary MDS. Stem cell transplantation had a significant beneficial effect on survival of patients with RAEB or RAEB-T as well as of patients included in intermediate II. or high risk subgroups. The impact of stem cell transplantation on survival of patients with RA or with low or intermediate I. risk was not significant. Therefore, further criteria should be taken in account for indication of stem cell transplantation in these subgroups of patients.

Humans↗

[Rearrangements of 11q in patients with hematologic malignancies].

BACKGROUND: The aim of this study was to investigate the rearrangement of MLL gene in bone marrow cells of patients with hematological malignancies with various types of 11q aberrations. These aberrations have been observed in acute lymphoblastic and acute myeloid leukemias as well as in myelodysplasias and lymphomas. METHODS AND RESULTS: Correlations of clinical characteristics, type of aberrations, diagnoses and survival of patients were evaluated. Using classical cytogenetic techniques we found 11q aberration in 17 patients with different hematological malignancies. FISH with dual color locus specific probe for MLL gene was used to confirm or exclude the rearrangement of this gene. Whole chromosome painting probes and multicolor FISH were performed for identification of chromosomes involved in complex translocations. Balanced rearrangements of 11q were found in 3 patients, in 14 patients unbalanced aberrations were found with rearrangement (4), deletion (4) and amplification (2) of MLL gene. In 7 patients no rearrangement of MLL gene was found. CONCLUSIONS: Correlation between clinical characteristics, type of aberrations, diagnoses and survival of patients was not significant, therefore further studies of larger cohort of patients are necessary to evaluate the prognostic value of 11q rearrangement.

Adult↗

Real-time quantitative PCR detection of WT1 gene expression in children with AML: prognostic significance, correlation with disease status and residual disease detection by flow cytometry.

The clinical significance of WT1 gene expression at diagnosis and during therapy of AML has not yet been resolved. We analysed WT1 expression at presentation in an unselected group of 47 childhood AML patients using real-time quantitative reverse-transcription PCR. We also showed that within the first 30 h following aspiration RQ-RT-PCR results were not influenced by transportation time. We observed lower levels of WT1 transcript in AML M5 (P = 0.0015); no association was found between expression levels and sex, initial leukocyte count and karyotype-based prognostic groups. There was significant correlation between very low WT1 expression at presentation and excellent outcome (EFS P = 0.0014). Combined analysis of WT1 levels, three-colour flow cytometry residual disease detection and the course of the disease in 222 samples from 28 children with AML showed remarkable correlation. Fourteen patients expressed high WT1 levels at presentation. In eight of them, who suffered relapse or did not reach complete remission, dynamics of WT1 levels clearly correlated with the disease status and residual disease by flow cytometry. We conclude that very low WT1 levels at presentation represent a good prognostic factor and that RQ-RT-PCR-based analysis of WT1 expression is a promising and rapid approach for monitoring of MRD in approximately half of paediatric AML patients.

Acute Disease↗

Location of the BCR/ABL fusion genes on both chromosomes 9q34 in Ph negative chronic myeloid leukemia.

We present two patients with Ph-negative chronic myeloid leukemia (CML) and fusion signal BCR/ABL on both chromosomes 9, located in region 9q34. The first case was a 27 years old man with CML. Molecular studies (RT-PCR) revealed the rearrangement in the major-BCR region and expression of chimeric BCR/ABL mRNA of b3a2 configuration. By classical cytogenetic studies (G-banding) karyotype 46,XY was found in short-term cultivated bone marrow cells and phytohemagglutinin (PHA) stimulated peripheral lymphocytes. FISH studies revealed the BCR/ABL fusion signals on both chromosomes 9 and green BCR signals on both chromosomes 22 in all mitoses studied. Detection of the alleles of ABL1 intragenic STR locus by fluorescence PCR followed by fragmentation analysis in the patient and his parents provided no information about transmission of the ABL gene. Quantitative assessment of BCR/ABL transcript level by RT-PCR showed 60 and 70% BCR/ABL positivity in two peripheral blood samples at 6,5 and 10,5 months after diagnosis, respectively, which does not correspond to the expression from two identical BCR/ABL hybrid genes. Therefore, the possible mechanism of the origin of two BCR/ABL fusion signals present on both chromosomes 9 could not be resolved and remains speculative. The second case was a 53 years old male with diagnosis of chronic phase of CML, with first sign of acceleration one month after diagnosis and death because of sepsis in blastic phase within four months. The cytogenetic findings were identical to those in case No. 1., i.e. karyotype 46, XY by G-banding, two BCR/ABL fusion signals on both chromosomes 9 and RT-PCR molecular studies proved b3a2 breakpoints. It is generally accepted that prognosis of the patients with fused BCR/ABL gene located on chromosome 9 is poor. The presence of two fused genes could be anticipated as two Ph chromosomes in accelerated and blastic phases of the disease. However, in our study, quantitative findings of BCR/ABL transcripts did not corresponded to the expression of two BCR/ABL genes originating from duplication. If this assumption is correct then the expression of both fused genes BCR/ABL was in case No. 1 equally suppressed and total expression reached about the level of one BCR/ABL gene.

Adult↗

[Importance of prognostic factors in patients with chronic B-lymphocytic leukemia at the time of diagnosis].

BACKGROUND: B-chronic lymphocytic leukemia (B-CLL) is the most common adult leukemia in the Western countries. Any routinely used staging system does not distinguish exactly the probable course of the disease at the time of diagnosis. Therefore the new prognostic factors, which help to assess the optimal therapeutic plan of patients, are searched intensively. METHODS AND RESULTS: We evaluated 154 patients with the B-CLL at the time of diagnosis--133 of them were retrospectively divided into two groups--one with stable form and the other with progressive form of the disease. We compared these two groups of patients with some of the prognostic factors (absolute lymphocyte count, the level of C-reactive protein, lactatdehydrogenase, beta-2-microglobulin, tumour necrosis factor, the immunoglobulin levels, the expression of CD38, FMC7, surface immunoglobulins, the type of bone marrow infiltration, and the cytogenetic abnormalities (trisomy 12, del(13)(q14), del(17)(p13) a del(11)(q23)). We found higher absolute lymphocyte count, level of beta-2-mikroglobulin, tumour necrosis factor, expression of CD38, light chains lambda, lower expression of FMC7 and less frequent nodular type of bone marrow infiltration by the patients with progressive disease. The correlation of the cytogenetic abnormalities and the course of the disease or stage according to the RAI et al. [27] staging system were not significant may be due to the small number of evaluated patients and short period of follow up. CONCLUSION: The routine evaluation of some risk factors in patients with B-chronic lymphocytic leukemia at the time of diagnosis helps to distinguish those with the probable more aggressive course of the disease and have the implication for the design of risk-adapted treatment strategies. The prognostic impact of the cytogenetic abnormalities and other risk factors has to be evaluated on larger group of patients during longer follow up period and repeated evaluations.

Biomarkers, Tumor↗

[Fluorescent in situ hybridization (FISH) in the diagnosis of acute childhood lymphatic leukemia (ALL)].

Classical cytogenetic analysis plays an important role in the diagnosis, classification, therapy monitoring and prognosis of patients with leukemia. Many recurrent cytogenetic abnormalities with major prognostic values have been described in childhood ALL. Hyperdiploidy and/or t(12;21) are associated with good prognosis, whereas t(9;22) and/or rearrangements of MLL gene correlate with poor outcome and therefore early detection of these abnormalities is very important. FISH can overcome some limitations of conventional cytogenetic and molecular-genetic analyses and due to high sensitivity specific chromosomal aberrations in mitoses and/or interphase nuclei can be detected. In the Center of Oncocytogenetics of the 3rd Medical Department for assessment of hyperdiploidy and structural rearrangements we use double-color FISH with centromeric and/or locus-specific probes and complex aberrations are ascertained by whole chromosome painting probes and multicolor FISH. Among 275 children with ALL examined during the last 8 years by different FISH methods we found seven patients with translocation t(9;22) and 14 patients with MLL rearrangements in bone marrow cells. Since 1988 we focus on detection of hyperdiploidy and/or t(12;21). High hyperdiploidy was found in 35 children, 10 of them had further complex rearrangements. Translocation t(12;21) was proved in 37 patients and complex rearrangements were found in 22 of them. FISH, cytogenetic and molecular-genetic analyses become obligatory for the first diagnostic examination as well as for monitoring of treatment effect in children with ALL.

Child↗

[Multicolor fluorescence in situ hybridization (mFISH].

Various techniques are now available for wide genome screening of alterations in copy number, structure and expression of genes and DNA sequences. Molecular cytogenetics has special techniques of comparative genomic hybridization (CGH), spectral karyotyping (SKY) and multicolor FISH (mFISH). We present principles of these methods, their use in molecular cytogenetic examinations of patients. We quote our experience with mFISH for analyses of complex chromosomal rearrangements in neoplastic cells and identification of inborn supernumerary marker chromosome. Further, we also review the first experiences with multicolor high resolution banding of chromosome (mBAND). This method was used for analysis of bone marrow cells of patient with myelodysplastic syndrome and deletion of chromosome No. 5. With mBAND exact breakpoints were localized. Multicolor fluorescence methods mFISH and mBAND becones the new tools for more precise analyses of inborn and acquired numerical and structural chromosomal rearrangements.

Chromosome Deletion↗