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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.

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.

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.

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.

Deletions of the long arm of chromosome 20 represent a common chromosomal abnormality associated with myeloid malignancies, in particular with myeloproliferative disorders (MPD), myelodysplastic syndromes (MDS), and acute myeloid leukemia (AML). Using G-banding cytogenetic techniques, we found clones with del(20q) in 36 patients with hematological malignancies examined in our laboratory during the years 2001-2003: in 23 patients as a sole cytogenetic aberration and in 13 patients together with other chromosomal changes. Fluorescence in situ hybridization (FISH) with a probe specific for the 20q12 region was used in all cases to confirm the presence of the clone with deletion. For patients with additional or complex chromosomal rearrangements, multicolor FISH (M-FISH) analysis was performed. Statistical evaluation of the prognostic impact of sex, age, diagnosis, and karyotype was performed. The survival time correlated with the type of chromosomal aberration; no significant differences in survival were found for sex, age, and diagnosis.

B-chronic lymphocytic leukemia (B-CLL) is the most common adult leukemia. Molecular genetic characterization of B-CLL has made significant progress and typical chromosomal anomalies have been assessed. The most frequent chromosomal abnormalities are deletions at 13q14, 17p13, and 11q22 approximately q23 and trisomy 12. The aim of this study was to establish incidence of chromosomal changes in bone marrow or peripheral blood cells (or both) of B-CLL patients using a molecular cytogenetic method, interphase fluorescence in situ hybridization (I-FISH), and to evaluate the prognostic implications. We performed I-FISH on bone marrow and blood smears from 217 B-CLL patients (124 male, 93 female). Trisomy 12 was found in 35 of the 217 (16%); deletion 13q14 was analyzed in 207 patients and found in 112 (54%). Deletion 17p13 was found in 34 (16%) out of 206 examined. Deletion of 11q23 was analyzed in 56 patients and was present in 7 (12%). Statistical analyses were performed to correlate the molecular-cytogenetic findings with disease status (stable versus progressive), Rai stage, CD38/CD19 antigen coexpression, immunoglobulin variable heavy chain (IgV(H)) mutational pattern, and other clinical and laboratory parameters. No apparent differences in distribution were noted for anomalies +12, del(13)(q14), or del(17)(p13) among patients with stable and progressive disease, and no consistent pattern in the distribution of type of genomic changes were found among various Rai stages and in CD38/CD19-positive or -negative patients. Patients without IgV(H) mutation had a worse prognosis; however, distribution of chromosomal abnormalities identified with FISH was the same for patients with and without IgV(H) mutations.

A clonal origin of hematopoiesis was studied by investigation of X-chromosome inactivation patterns (XCIP) in isolated granulocyte, CD14(+) and CD3(+) subpopulations obtained from bone marrow and peripheral blood of 36 female patients with primary myelodysplastic syndrome (MDS). Clonality was assessed by PCR amplification of polymorphic short tandem repeats of the human androgen receptor (HUMARA) gene and by investigation of silent polymorphism of iduronate sulphatase (IDS) or p55 genes. On the basis of results in a control group of 20 healthy age related females, a ratio of at least 9:1 between the two alleles was considered a significant marker of monoclonal hematopoiesis. Ten of the 11 patients with advanced forms of MDS (RAEB, RAEB-T, CMML) had clonal granulocytes and CD14(+) cells in peripheral blood. In patients with early disease, only 2 out of 11 patients (18%) with RA or RARS, according to WHO classification, had clonal granulocytes and CD14(+) cells in peripheral blood and bone marrow and 2 other patients with 5q-syndrome exhibited extremely oligoclonal granulocyte subpopulation in bone marrow. In contrast, we found clonal granulocytes in 12 out of 14 patients (86%) with refractory cytopenia with multilineage dysplasia (RCMD) and 8 of them simultanously exhibited clonal CD14(+) cells. Estimated 3 years survival of patients with early disease and clonal cell subpopulations was 61% as compared with 88% in patients without clonal hematopoiesis. Karyotype abnormalities were detected in 11 of the 25 females with early disease. Clonal patterns were present in 7 out of 8 patients with abberations diagnosed by routine cytogenetics, nevertheless, FISH revealed 5q deletion in 3 patients without signs of clonality in XCIP assay. No correlation was found between the presence of clonal subpopulations and the degree of telomere shortening in early MDS. Despite some limitations, the measurement of XCIP remains a sensitive tool for diagnosis of the first transforming mutation in the clonal development of MDS especially when combined with FISH and when an age related group is used to establish an appropriate allele ratio to exclude constitutional or acquired skewing. The occurrence of clonal cell subpopulations in most of the RCMD patients in contrast to RA may reflect a proposed multistep pathogenesis of MDS with dysplastic changes limited to erythropoiesis in early step and with subsequent development of multilineage dysplasia. The results also support the usefulness of separation of RCMD from 'pure' RA; however, a more complex insight combining different molecular techniques performed in a large number of patients is needed for refined classification of MDS on the basis of new molecular prognostic factors and for indication of more effective targeted therapy.

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.

Telomere length was evaluated by terminal repeat fragment method (TRF) in 50 patients with myelodysplastic syndromes (MDS) and acute myelogenous leukemia (AML) arising from MDS and in 21 patients with untreated primary AML to ascertain, whether telomere erosion was associated with progression of MDS towards overt leukemia. Heterogeneity of TRF among MDS FAB subgroups (P=0.004) originated from its shortening in increased number of patients during progression of the disease. Chromosomal aberrations were present in 32% MDS patients with more eroded telomeres (P=0.022), nevertheless a difference between mean TRF in the subgroups with normal and abnormal karyotype diminished during progression of MDS. A negative correlation between individual TRF and IPSS value (P=0.039) showed that telomere dynamics might serve as a useful prognostic factor for assessment of an individual MDS patient's risk and for decision of an optimal treatment strategy.

Prenatal acquisition of leukaemia-associated gene rearrangements is a well-established phenomenon. This is the first report of a complex cytogenetic clone, in association with an ETV6/AML1 fusion, developing in utero. Identical twin girls, aged 4 years, developed ETV6/AML1-positive acute lymphoblastic leukaemia (ALL) within 3 months of one another. Both demonstrated an identical four way, variant t(12;21). There was gain of an AML1 signal in twin 1 and loss of an ETV6 one in twin 2 at interphase. This unique case study demonstrates that ETV6/AML1 fusion and the associated complex chromosomal rearrangements occurred in utero. Clonal expansion of the abnormal cell in one twin was followed by metastasis to the other. There was a prolonged preleukaemic phase, which lasted well into childhood. The short time between the two diagnoses of ALL suggests a common precipitating event. The significance of the different secondary markers remains unclear., (Copyright 2004 Blackwell Publishing Ltd)

A retrospective analysis of the relationship between the initial classification according to either FAB or WHO criteria, the presence of risk factors and the type of therapy including stem cell transplantation (SCT) on the survival was performed in a group of 106 patients with primary myelodysplastic syndrome (MDS) of FAB RA subtype. Allogeneic SCT early in the course of the disease did not significantly affect median survival in RA patients evaluated either according to FAB criteria (63.2 months in 17 SCT patients versus 64.4 months in 89 non-transplanted (non-SCT) patients) or in subgroups classified separately according to WHO (64.0 months in SCT versus 91.0 months in non-SCT RA patients and 66.2 months in SCT versus 43.0 months in non-SCT refractory cytopenia with multilineage dysplasia (RCMD) patients) or International Prognostic Scoring System (IPSS) criteria despite decreased incidence of leukemic transformation (5% in SCT versus 32% in non-SCT patients). Neither univariate or multivariate analysis of different clinical and laboratory parameters revealed a significant effect of SCT on 3 or 5 years survival in RA patients. The most probable explanation was a relatively high rate of transplantation related mortality (41%) on one hand together with a slow disease progression towards leukemia (24% at 5 years in non-SCT) on the other hand. A more refined stratification of patients based on the combined WHO morphology classification and IPSS cytogenetic criteria revealed subgroup of 11 non-SCT patients with RCMD and poor karyotype with median survival significantly different from that in five SCT patients (9.2 months in non-SCT versus 89.3 months in SCT, P=0.05). Thus, combined WHO morphology/IPSS cytogenetics criteria may be helpful for identification of the high risk patients with the RA group who may benefit from early SCT despite the relatively high incidence of SCT-related complications.

Kinetics of BCR-ABL transcript levels were determined in 19 patients with chronic myeloid leukemia (CML) treated with imatinib for chronic (CP) or accelerated phase (AP). Patients could be divided into three groups with: (1) a sharp and sustained decrease in BCR-ABL transcript level reaching 0.1-0.002% (only CP); (2) an early BCR-ABL overexpression up to 2500% (only AP); and (3) a stable trend with BCR-ABL values between 10 and 100% (CP, AP). In group 1, relapses were not developed within the follow-up; in group 2, patients progressed to blast crisis; in group 3, BCR-ABL overexpression appeared after 12 months in some patients and disease relapses were found 2-16 weeks later. It is summarized that BCR-ABL transcript kinetics clearly characterize responses to imatinib treatment and are highly predictive for disease progression.

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.

We monitored DLI treatment of 13 post-SCT relapses using quantitative competitive (QC) RT-PCR for BCR-ABL (sensitivity 10(-5)) and compared responses to DLI alone and DLI in combination with interferon-alpha (IFN). Ten relapses (one blast crisis, five cytogenetic and four molecular) were treated with DLI+IFN, three relapses (one cytogenetic, two molecular) were treated with DLI alone. Except the patient treated in blast crisis, who died, all the patients treated with DLI+IFN achieved complete molecular remission, with the median time interval of 3.9 months (range 0.25-10.5 months). None of the three patients treated with DLI alone have achieved complete molecular remission up to now, i.e. 32, 45, and 50 months after DLI. However, in all of them some decrease of BCR-ABL transcript level was detected. Although the retrospective analyses did not confirm that IFN improved the response to DLI, our results based on sensitive molecular monitoring suggest that DLI effect, at least in some patients, is supported by IFN administration.

Acute myeloid leukemia (AML) carrying inversion or translocation of chromosome 16 is usually associated with the FAB M4Eo morphological subtype and belongs to AMLs with a relatively favorable prognosis. At the molecular level, it is associated with a disease-specific fusion gene, CBFbeta/MYH11. Previously, 10 different types of CBFbeta/MYH11 fusion transcripts have been described in the literature, 7 of them are still known as unique cases. In the current study, peripheral blood and/or bone marrow samples from 265 AML patients were tested for the presence of the CBFbeta/MYH11 fusion using RT-PCR and 12 (4.5%) positive cases were identified. The most common type A CBFbeta/MYH11 transcript was confirmed in 11 patients. The transcript in the remaining one (a 71-year-old female) was different and sequence analysis allowed us to classify it as CBFbeta/MYH11 type J. In contrast to the first type J case previously reported from Australia, this patient exhibited a typical FAB M4Eo morphology. The evidence of the second case indicates that the type J breakage might be a non-random event within the MYH11 gene.

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.

A prognostic impact of WHO classification of myelodysplastic syndrome (MDS) was studied in a group of 103 primary MDS patients with refractory anemia (RA) according to French-American-British (FAB) classification. Median survival of 37 patients with RA according to WHO criteria of 85.2 months was significantly different from that in both 37 patients with refractory cytopenia with multilineage dysplasia (RCMD) (47.0 months, P=0.002) and 29 patients with 5q- abnormality diagnosed by routine chromosome banding (36.2 months, P=0.0002). A more detailed karyotype analysis with fluorescent in situ hybridization (FISH) techniques confirmed 5q deletion as a sole cytogenetic abnormality in only 12 out of 29 patients, in 4 patients 5q- was associated with complex abnormalities involving 5q region, 13 patients had 5q deletion combined with further karyotype abberations outside 5q. No difference in median survival and estimated 3 years survival was observed between RA patients, patients with 5q- syndrome according to WHO morphology criteria and patients with 5q- as a single abnormality confirmed by FISH in contrast to patients with either additional 5q abberations or further karyotype changes not involving 5q. The same difference was also observed in time to 25% of patients evolving to acute myeloid leukemia (AML). Our study confirmed usefulness of separation of RCMD from RA. RCMD represents a poor prognostic subgroup of MDS clearly distinct from pure RA mainly due to short survival connected with progressive bone marrow failure and increased risk of leukemic transformation. We also suggest to define 5q- syndrome as primary MDS of FAB type RA with 5q deletion as a sole cytogenetic abnormality confirmed by FISH analysis. This definition enabled us to discriminate 5q- patients with favorable prognosis similar as in RA from those with poor outcome associated with 5q- combined with complex abnormalities involving either 5q or regions outside 5q.

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.

In a 66 years old female patient with acute myeloblastic leukemia (AML) complex chromosomal rearrangements involving 11q23 were diagnosed by G-banding and confirmed by different fluorescence in situ hybridization (FISH) techniques. The amplification of MLL gene differed in various sidelines as shown by locus specific probes for 11q23 and 11q13. Complex karyotype rearrangements involving deletions del(5)(q31) and del(7)(q31) were verified by multicolor fluorescence in situ hybridization (mFISH).

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.

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.

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.

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.

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.

Deletion of part of the long arm of chromosome 5 (5q-) is one of the most common structural aberrations in patients with myeloid disorders. The deletion is interstitial and the deleted segment is variable in size and breakpoint localization. Precise analysis of chromosomal breakpoints proved that band 5q31 is the most common deleted region. Extensive molecular studies have been performed to identify one or several tumor suppressor gene(s) in this critical region. Although these genes have not been identified as yet, the candidate genes are being intensively studied. Isolation and characterization of tumor suppressor genes will lead to the understanding of molecular mechanisms of normal hematopoiesis and that of leukemic transformation.

Background: Trisomy 12 was found to be the most frequent chromosomal aberration identified by conventional cytogenetic studies of bone marrow cells and peripheral lymphocytes of patients with CLL. Molecular-cytogenetic techniques which enable examination of dividing and/or non-diving interphase nuclei (I-FISH), proved existence of other chromosomal abnormalities, mainly deletions, which could have in CLL patients relation to the origin, course and prognosis of the disease., Methods and Results: During the last two years bone marrow chromosomes of all patients with CLL were examined by G-banding and by I-FISH. The numerical changes of chromosome 12 were followed by centromeric DNA probe in dividing and non-dividing cells. The small deletions were ascertained by locus specific probes for 13q14 (Rb gene), 17p13 (p53 protein) and 11q23 (MLL gene). These genes are responsible for cell division and their function is probably in connection with neoplastic process. It is of interest whether numerical and structural chromosomal rearrangements are primary or secondary changes and what is their impact on etiology of CLL. 93 patients were examined by DNA prove CEP12 and trisomy 12 was found in 24 of them (25.8%), the range of the clone was 2.5-75.5% of the screened cells. Deletion del(13)(q14) was examined by probe D13S319 in 73 patients and proved in 24 of them (32.8%), pathological clone ranged 2.5-80.0% of the cells. Deletion del(17)(p13) was found in 14 patients out of 61 examined by probe LSI p53 (22.9%). The extent of the clone was 2.5-34.0% of examined cells. Deletion 11q23 was not ascertained in any of 11 patients by means of probe LSI 11q23 (MLL). All probes used for FISH were manufactured by VYSIS., Conclusions: FISH is very sensitive method, suitable for molecular-cytogenetic examination of leukemic patients. With I-FISH the deletion of 13q14 was ascertained as the most frequent chromosomal aberration in series of 73 patients with CLL. We continue to increase the number of patients screened by I-FISH with all eligible DNA probes and start the prospective study on patients with chromosomal pathology. We will correlate the immunophenotype, morphology, clinical course and prognosis with karyotypic findings.

Fluorescence in situ hybridization (FISH) using specific probes for the 5q31-32 region and a whole chromosomal painting (WCP) probe for chromosome 5 were used to corroborate the results of classical cytogenetic examinations performed on G-banded chromosomes of 77 patients with hematological malignancies. Using classical cytogenetic methods, we suspected the presence of clones with a deletion 5q in 63 patients, and complex rearrangements with involvement of chromosome 5 in 14 other cases. Fluorescence in situ hybridization proved the occurrence of deletion 5q31 in 23 patients and ascertained translocations of part of the long arms of deleted chromosome 5 with missing region 5q31 in 12 patients. In 2 cases, the 5q31 region was translocated to other chromosomes as a part of complex rearrangements. The combination of classical cytogenetics and FISH with specific probes for the 5q31 band yielded cytogenetic results in 35 cases. Routine FISH detection of deleted regions was possible by commercially available cosmid probes for the 5q31 chromosomal band. The interpretation of small deletions and frequent involvement of the deleted chromosomes 5 in complex translocations were ascertained by WCP probes.

Background: According to the literature approximately 50% of patients with Turner's syndrome have karyotype 45,X in every cell, the rest have two or more cell lines with mosaics of sex chromosomes. New methods have shown that the mosaicism is probably more frequent than expected from classical cytogenetics examinations. The aim of this study was to detect numerical changes of sex chromosomes in mitoses and interphase nuclei of cultivated peripheral lymphocytes of patients with Turner's syndrome by means of FISH, to compare the sensitivity of classical and molecular-cytogenetic methods and to estimate the values obtained in 10 control healthy females with karyotype 46,XX., Methods and Results: 18 females with Turner's syndrome were examined. Karyotype 45,X was found by classical cytogenetics in all cells of 9 females. The 9 remaining patients had sex chromosome mosaicism of two or more clones. In all patients FISH confirmed the results of classical cytogenetic methods and in 6 patients (30%) it revealed other clones previously not detected., Conclusions: Higher sensitivity of FISH enables more precise detection of mosaicism of cell lines than classical cytogenetics and this technique is more suitable for examinations of patients with Turner' syndrome.

Background: It was found by classical cytogenetic methods that approximately 80% of X-chromatin positive mates have karyotype 47,XXY and the rest have mosaicism of sex chromosomes. More sensitive molecular-cytogenetic studies allow to evaluate even non-dividing cells of different tissues and therefore they suggest that there could be more frequent occurrence of patients with numerical changes of gonosomes than quoted in the literature. The aim of this study was to detect numerical changes of sex chromosomes by means of double-colour fluorescence in situ hybridisation (FISH) in dividing and non-dividing nuclei of peripheral lymphocytes of males with Klinefelter's syndrome, to compare clinical findings with cytogenetic results, to determine differences in sensitivity of classical and molecular-cytogenetic methods and estimatere the values obtained with controls (healthy males)., Methods and Results: 26 males with previously diagnosed Klinefelter's sy were examined. Classical cytogenetic studies consisted of evaluation of at least 20 G-banded mitoses of 72 h cultivated peripheral blood. The results we obtained: 19 patients with 47,XXY, 5 mosaics 47,XXY/46,XY, 1 patient mosaic 46,XX/47,XXY and 1 patient 48,XXYY karyotype. The results of double colour FISH and classical cytogenetics were compared and mosaics of cells with normal karyotype 46,XY was found. As a control 10 healthy males were examined and mosaics of gonosomes were not detected., Conclusions: FISH method has a higher sensitivity for detection of sex chromosomes mosaics than classical cytogenetics. The existence of small cellular side clones with 46,XY karyotype or numerical sex chromosomes changes which were not determined previously can be proved by FISH in patients with Klinefelter's sy.

Presence of double minute chromosomes (dmin) is rare in bone marrow cells in patients with preleukemia and leukemia. We describe a case of myelodysplastic syndrome-refractory anemia with excess of blasts (MDS-RAEB) associated with two unrelated pathological chromosomal clones that developed during the progression of the disease. The patient was followed cytogenetically for a period of 4 years. At the time of transition into RAEB-T and later to acute myeloid leukemia (AML), dmin were associated with resistance to chemotherapy. Fluorescence in situ hybridization study proved that the dmin in this case were c-MYC amplicons. At the terminal stage of the disease, dmins were present in all 50 analyzed cells.

Background: The BCR/ABL and MLL/AF4 fusion genes--resulting from t(9;22)(q34;q11) and t(4;11)(q21;q23) translocations, respectively--are considered as a high risk prognostic factors in children with acute lymphoblastic leukaemia (ALL). Their presence in malignant cells indicates patient for the most intensive antileukaemic therapy regardless of the other criteria. In contrast, the most common non-random chromosomal aberration in paediatric ALL--translocation t(12;21)(q12;q22)--is associated with a favourable prognosis. The examination of these rearrangements is important for the stratification of patients to the risk groups and also provides the most sensitive and specific tool for minimal residual disease (MRD) follow-up., Methods and Results: This study comprises 241 patients with ALL from Czech and Slovak Republics younger than 18 years at diagnosis. They were examined for presence of m-RNA of fusion genes BCR/ABL, MLL/AF4 and TEL/AML1 by reverse transcriptase-polymerase chain reaction (RT-PCR) method. Seven out of 197 (3.6%) carried MLL/AF4 fusion gene, but among infants it was 56% (5 out of 9). BCR/ABL positivity was found in 2.5% (7 out of 240) and TEL/AML1 in 21.7% (41 out of 189) cases. Event free survival (EFS) curves demonstrate the clinical impact of these hybrid genes on patients' prognosis. Moreover, we present the possibility of the monitoring of MRD levels in follow-up samples of these patients., Conclusions: All particular rearrangements were found only in a cohort of patients with B-precursor ALL (or hybrid leukaemia), which constitutes 85% of our group. Presence of BCR/ABL or MLL/AF4 fusion gene is associated with poor prognosis and is indispensable condition for correct stratification of patients to the risk groups according to treatment protocols. Hybrid gene TEL/AML1 defines subgroup of children with better prognosis and due to its high frequency provides us with a very useful tool for MRD detection.

The BCR/ABL rearrangement, the molecular hallmark of chronic myelogenous leukaemia (CML), is rare in acute myeloid leukaemia (AML), being detected in approximately 1% of cases. In the vast majority of CML cases the breakpoint on chromosome 22 falls in the so-called major breakpoint cluster region of the BCR gene. Only a few cases of CML with breakpoint in the minor or in the micro bcr region have so far been reported. The micro breakpoint position has been associated mainly with a mild form of CML, defined as Philadelphia chromosome-positive chronic neutrophilic leukaemia (Ph-positive CNL). Using reverse transcription-polymerase chain reaction (RT-PCR) we report a patient with an acute myeloid leukaemia phenotype at diagnosis who showed a BCR/ABL rearrangement with a breakpoint located in the micro bcr region (e19a2 junction). Cytogenetic analysis showed a progression of the malignant clone, finally leading to cells with two Ph chromosomes, trisomy 8, isochromosome 17q and deletion of the long arms of chromosome 7. The findings of chromosomal changes point to a possibility of blast crisis of CML with a clinically silent chronic phase. Immunoprecipitation and auto-phosphorylation assay revealed the expression, by the patient's blast cells, of an abnormal P230 BCR/ABL protein, which showed for the first time that this protein was constitutively activated in primary cells from patients. This finding may contribute to the understanding of the role of the BCR/ABL rearrangements in determining different leukaemia phenotypes ranging from acute lymphoid and myeloid leukaemias to mild chronic neutrophilic leukaemias.

Background: The conventional, or standard, treatment of chronic myeloid leukaemia (CML) with hydroxyurea and busulfan has no marked influence on its course or duration. Interferon (IFN) alpha administration has, on the other hand, been shown to induce not only a haematological but also cytogenetic response, i.e. partial or complete bone marrow repopulation by Ph-negative cells. This has triggered studies comparing IFN and conventional chemotherapy. The present work had the purpose to gain experience with IFN alpha treatment and compare the results with hydroxyurea and busulfan treatment, in the chronic phase of CML., Methods and Results: Therapeutic results obtained in 30 patients given IFN alpha and 30 others given conventional chemotherapy were evaluated retrospectively. In spite of the short time of IFN administration (4-27 months), significantly more complete haematological responses (83%) were observed in this than the conventional chemotherapy group (57%). Cytogenetic responses were achieved in 36%, complete cytogenetic remission in 20% of IFN-treated patients. Conventional chemotherapy produced no cytogenetic effect., Conclusion: The results obtained confirm the value and efficacy of IFN-alpha treatment in CML patients, especially if it is started early and the dose is effective. Regular cytogenetic monitoring is necessary. Longer follow-up of the patients will be necessary for evaluation of the IFN effect on the length of their survival.

We report three cases of acute myeloid leukemia (AML) with a near-tetraploid karyotype in most metaphases while lacking chromosomal abnormalities typical for AML. All patients, 63, 72 and 81 years old, were female. In two cases, AML was diagnosed 5-7 months after a cytopenic period while the third patient had a secondary AML after therapy for a pleural tumor. Leukemic blasts were classified as AML M0, AML M1 and AML without further specification. Two patients died on the 18th and 52nd day after the start of cytotoxic chemotherapy, the third patient refused chemotherapy and died 22 days after the diagnosis. The three patients may represent a distinct AML category with the following features: (1) the near-tetraploid karyotype in most bone marrow metaphases examined at diagnosis of AML; (2) the presence of very large myeloid blasts in the bone marrow and dysplastic changes in erythroid and/or megakaryocytic lineages pointing to the origin of AML in pluripotent myeloid progenitor cells; (3) the expression of the CD34 antigen; (4) the low growth of granulocyte-macrophage colony forming cells in culture; and (5) the presence of a preleukemic phase, a higher age and a poor prognosis.

The results of the cytogenetic study of bone marrow cells from 110 consecutive patients with primary acute myeloid leukemia (AML) who were diagnosed and treated between 1991 and 1996 at one tertiary care institution were compared with similar data obtained between 1982 and 1988 in 130 patients. Despite improvements in cytogenetic techniques (namely FISH methods, applied in all patients with abnormal karyotypes since 1990) in recent years we have observed a significantly lower frequency of abnormal karyotypes: 52.7% versus 77.7% (p = 0.001). This was mainly due to the decreased frequency of patients with +8, -5, -7 and inv(16). The survival rate (excluding the patients who underwent a bone marrow transplantation) was only slightly increased.

Background: An injury to the hemopoietic stem cell may lead to the aplasia of hemopoiesis, myelodysplasia and to an unregulated myeloproliferation. There is not a strict demarcation of them, so that mixed syndromes can develop as are hypoplastic syndromes on one side and mixed myelodysplastic and myeloproliferative syndromes (MDS-MPS) on the other side., Methods and Results: Among our 616 pts with MDS we looked for those cases, who had beside myelodysplasia signs of myeloproliferation with increased number of blood cells. They were examined in detail including bone-marrow histology, bone marrow cultivation, cytogenetics and bcr-abl gen. Signs of MDS-MPS were found in 22 patients at the first contact with the patient (13 patients had thrombocytemia and 9 patients had leukocytosis). Further 7 patients were diagnosed as MDS, proliferative syndrome developed after several months (MDS-MPS in evolution). The level of thrombocytemia was relatively stable, the number of leukocytes was progressive. All subtypes of MDS were found. All subjects had variable degree of anemia. Ring-sideroblasts and myelofibrosis were frequent finding in MDS-MPS. Men prevailed in patients with leukocytosis. Cytogenetic and cultivation findings were similar to MDS cases, deletion of long arm of chromosome 20 was present in 3 patients. Five patients transformed to acute myeloid leukemia., Conclusions: Sings of myelodysplasia and myeloproliferation were found in 4% of our MDS patients, designated as mixed myelodysplastic and myeloproliferative syndrome (MDS-MPS). In this syndrome beside evident signs of myelodysplasia thrombocythemia or leukocytosis with the release of bone marrow precursors are present. In only one case polycythemia was encountered.

Background: The cytogenetic examination of the bone marrow (BM) depends on the presence of sufficient amount of mitoses on slides prepared for analysis. The quantity and the quality of mitoses found in BM cultivations of patients with MDS is rather low and a new possibilities to increase the proliferative activity of the cells are under research. One promising method is the stimulation of the BM cells with addition of hemopoietic growth factors. The aim of this study was to evaluate in vitro influence of GM-CSF on the proliferative activity and the representation of chromosomally different clones in the patients with MDS., Methods and Results: The bone marrow cells of 25 patients (12 males, 13 females) of mean age 52.5 years (range 20-85) were examined. The mitotic index (MI), quality of mitoses and chromosomal complement were evaluated in 24 and 72 h cultivations with 100 and 1000 ng/ml GM-CSF concentrations. No stimulation was used in control cultivations. After 24 h of cultivation 100 ng/ml of GM-CSF increased the mitotic index (112%) but lowered the quality of mitoses (-7.6%). On contrary after 72 h of presence of 100 ng/ml GM-CSF both parameters showed the decrease (MI-30%, quality of mitoses-36%). Similar effect had the addition of 1000 ng/ml for 24 h of cultivation (MI-5%, quality of mitoses-11%). Twelve patients had normal karyotype on all studied cells in every type of cultivation. The ratio of chromosomally abnormal clones was the same in six other cases and only non-significant changes appeared in seven patients after GM-CSF stimulation., Conclusions: The influence of GM-CSF on the division of the bone marrow cells is strictly individual. GM-CSF in concentration of 100 ng/ml in 24 h cultivation increases the activity of proliferation, but at the same time moderately decreases the quality of mitoses. The presence of GM-CSF has not changed the cytogenetic results.

The author evaluates diagnostic and therapeutic results in nine patients with Behcet's disease investigated at the uveological ambulance of the First Ophthalmological Clinic, Medical Faculty Charles University in Prague during 1987-1996. Anterior uveitis with hypopyon was recorded twice as frequently as retinal vasculitis. Chronic CME, secondary glaucoma and occlusive vasculitis were the most serious complications of ophthalmological manifestations of BD. Ulcerations of connective tissue and skin manifestations of BD were found most frequently in the authors patients. In two thirds of the patients also the risk phenotype HLA B5 was recorded.

The authors draw attention to the different ophthalmological manifestations of Wegener's granulomatosis in two patients examined at the First Ophthalmological Clinic of the First Medical Faculty, Charles University, Prague. The patients complaints led later to establishment of the diagnosis of WG or its relapse. Combined immunosuppressive treatment with steroids and cyclophosphamide relieved the ocular as well as general manifestations of WG.

The author investigated the rate of phenotype HLA-B27 and systemic diseases in patients with acute anterior uveitis (AAU) in our geographical area. The evaluated clinical differences of AAU manifestations in HLA-B27 positive and HLA-B27 negative patients in a group of 104 subjects followed up for a 10-year period. The patients were under 40 years of age. Men were affected twice as frequently as women. HLA B27 positive AAU is manifested above all by serofibrous exsudation into the anterior chamber and by more frequent relapses. In patients with early treatment there were fewer complications and the prognosis was favourable. AAU in HLA-B27 positive patients is associated in 65% with rheumatic disease. In our population it is above all ankylosing spondylitis and Reiter's disease. In 71% rheumatic diseases were manifested in men. Despite the different clinical course of AAU HLA-B27 positive and negative patients, during long-term follow up the visual acuity is not markedly altered in any of the investigated groups.

Objective: Evaluation of experience with the diagnosis and treatment of intermediate uveitis in the Czech population., Methods: The retrospective study summarizes the results assembled in 21 patients (37 eyes) investigated at the First Ophthalmological Clinic in 1988-1995., Results: A diffuse type of inflammation was revealed in 15 patients (26 eyes), exsudative type in 6 patients (11 eyes). In three patients the inflammation did not call for treatment. Long-term remission was achieved in 3 patients by periocular injections of steroids, in 11 patients by systemic Prednisone treatment, in 4 patients by combined immunosuppression. In one patient cryotherapy was performed, in two patients PPV. In 31 eyes (84%) vision was the end of the observation period 6/12 better., Conclusion: From the results of the investigation ensues that intermediate uveitis occurs in our geographical zone more frequently in younger age groups and is manifested as a rule by a milder, diffuse type of inflammation. The prerequisite of successful patient care is early diagnosis and correct indication of treatment.

Necrotizing herpetic retinopathies are serious, usually rapidly progressive diseases of retina. Three well defined syndromes can be outlined: acute retinal necrosis, progressive outer retinal necrosis and CMV retinitis. Two cases of acute retinal necrosis, where the clinical picture was probably influenced by the corticosteroid use are described. The overview of clinical manifestation and therapy of these syndromes is given.

The authors evaluated the importance of a large scale of laboratory examinations and specialized examinations in a group of 174 patients with endogenous uveitis examined at the uveological ambulance of the First Ophthalmological Clinic of the First Faculty, Charles University Prague. Laboratory examinations which are part of screening examinations are of little value for the diagnosis of uveitis. Alone they are unable to assess its type or prognosis. They cannot be recommended for routine work in the field. Only the incidence of phenotype HLA B27 in patients with anterior uveitis is, as compared with the healthy population, statistically significant (p < 0.005). Aimed collaboration with specialists from other disciplines is more important. The latter can on the basis of aimed examinations confirm or rule out systemic disease of a patient with uveitis suspected by the ophthalmologist.

Topical 5% povidone-iodine for the treatment of corneal ulcers was observed in Sierra Leone, West Africa by one of us (D.J.D.). To test the efficacy of topical 5% povidone-iodine for infectious keratitis, experimental Pseudomonas aeruginosa keratitis was induced in 12 rabbits by first abrading the central 3 mm of corneal epithelium. Thirty milliliters of broth of P. aeruginosa strain ATCC 27835 (1.8 x 10(7) viable bacteria) was dropped twice on the wounded cornea. After 22 h, all corneas were clinically infected. Eight rabbits were treated with 5% povidone-iodine solution and four with 0.9% NaCl solution. All were given hourly drops. Twenty-four hours after treatment began, the central 8-mm button of the infected cornea was excised, homogenized, and serial dilutions plated onto MacConkey agar. The total number of viable Pseudomonas organisms was calculated. The treatment group had 5.2 +/- 0.4 CFUs (colony-forming units) per cornea. The control group had 4.8 +/- 0.4 CFUs per cornea (p = 0.11). The clinical scores (Hobden grading system) were 6.9 +/- 1.5 for the treated group and 7.3 +/- 2.5 for the control group (p = 0.74). There was no statistical difference between the treated and control groups. Povidone-iodine (5%) is not effective in the acute treatment of P. aeruginosa keratitis in this rabbit model.

Aplastic anemia, myelodysplastic syndromes (MDS) and chronic myeloproliferative diseases (MPD) are stem cell disorders. There is no clear-cut demarcation of them. Hypoplastic MDS displays features of aplastic anemia and MDS, on the other side mixed myelodysplastic and myeloproliferative syndromes (MDS-MPS) develop. In our collection of 566 MDS patients, features of myelodysplasia as well as myeloproliferation, MDS-MPS, were present in 25 patients (4.4%). Twelve patients had at the time of diagnosis megakaryocytic proliferation and thrombocythemia beside signs of MDS, and seven had myelodysplasia with granulocytic proliferation and leukocytosis. In another six patients, MDS was the first diagnosis and the proliferative phase developed later during the course of the disease. These patients can be characterized as MDS-MPS in evolution. All subjects had a variable degree of anemia. While the level of thrombocythemia has been relatively stable, the number of leukocytes has been progressive, but rarely extended beyond 100 x 10(9)/l. Ring-sideroblasts and myelofibrosis were frequent findings. Two more homogeneous MDS-MPS groups emerged in our analysis: sideroblastic anemia with thrombocythemia and a group fulfilling the criteria of Philadelphia chromosome negative and bcr-abl negative "atypical chronic myeloid leukemia (aCML)'. One patient with thrombocythemia and three with leukocytosis (23%) transformed to acute myeloid leukemia (AML). Men prevailed (12/13) in patients with leukocytosis and MDS-MPS in evolution. Of the 46% MDS-MPS patients with chromosomal aberrations, del(20)(q) is of interest.

Toxoplasmosis chorioretinitis is the most frequent posterior uveitis. Different treatment modes are used for its therapy. Classical is the combination of 50 mg of pyrimethamine with 4 g of sulphadiazine and corticosteroids. In this study the results of treatment with lower doses of pyrimethamine together with long-acting sulphonamide are reported. Twelve patients were treated with Fansidar, combination of 25 mg of pyrimethamine and 500 mg sulphadoxine. The treatment consisted of a loading dose of two tablets of Fansidar, followed by one tablet a day. Prednisone 0.5 mg/kg/day was added and gradually tapered off. Patients were treated for 28 days on average (range 21-50 days). In 83% of patients the scar was considerably smaller than original lesion (on average the scar represented 25% of original lesion). Three months after the treatment the visual acuity was 6/9 or better in 83% of patients. No side-effects of the treatment were observed. Lower doses of pyrimethamine with suphadoxine in an easy once a day treatment regime could be an alternative and cost-effective therapy for ocular toxoplasmosis.

We identified cytogenetically unrelated clones in the bone marrow of 12 of 240 patients with myelodysplastic syndrome (MDS) and in 3 of 232 patients with acute myeloid leukemia (AML). In addition, unrelated single-cell abnormalities were found in six MDS and two AML patients. The most commonly encountered abnormalities present in the unrelated clones in patients with refractory anemia (RA) were del(5q), +8, and -7. In blastic types of MDS and AML trisomy 8 was found in two of eight patients while in the remaining cases the chromosome abnormalities were diverse and nonspecific. The presence of the chromosomally unrelated clones, together with recent data on the early appearance of monoclonality provided by molecular biology studies, support the interpretation that aberrations such as +8 and del(5q) are actually secondary abnormalities that develop during tumor progression in a cell with a primary submicroscopic genomic rearrangement.

The authors present an account of surgery of complicated cataract in 20 patients with anterior and intermediate uveitis. During a one-year follow-up period they evaluate the difference of postoperative development and visual acuity in extracapsular extraction without or with implantation of an intraocular lens. In 10 patients (5x m. Fuchs, 3x anterior uveitis, 2x intermediate uveitis) they performed only ECCE. In 10 patients with the same diagnosis an intraocular lens was implemented. The authors did not find marked differences between the ECCE operation and ECCE operation with an intraocular lens in patients with uveitis. The visual acuity improved in all 20 patients, a marked inflammatory reaction in the anterior chamber was observed in both groups only during the first days after surgery. The two groups did not differ markedly as regards late complications. From the investigation ensues that implantation of an intraocular lens is well tolerated in patients with anterior and intermediate uveitis assuming a minimum 12-week remission of the disease.

Sixteen patients with relapsing or chronic HSV keratouveitis were treated during a new attack by acyclovir 15 mg/kg/day by the i.v. route for 5 days with local combination of acyclovir 3% ung. and steroids. In all 16 patients improvement of signs of keratouveitis occurred on the fourth day of therapy, in 10 patients with improvement of visual acuity. In 5 patients perforating keratoplasty was performed on account of turbidity of the cornea. The authors observed four relapses of the disease in the course of 12 months after termination of treatment.