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D Dvoráková

Publications and source records attributed to D Dvoráková.

At least 19 recordsLinked to original sources
PubMed2006

[Isolated lymphadenopathy as the first presentation of systemic mastocytosis--description of two cases].

Presented are two cases of systemic mastocytosis in 46- and 63-year-old women, where the correct diagnosis was established in randomly disclosed cervical respectively intraabdominal lymphadenopathy. Both cases lacked characteristic skin and systemic mast-cell mediator symptoms at the time of histologic diagnosis. The first case was classified as a indolent systemic mastocytosis without any proven genetic alteration, the second one met the criteria of aggressive systemic mastocytosis with eosinophilia, where the point mutation asp816val in c-kit gene was confirmed and the patient responded unexpectedly well to Gleevec. Discussed are both conventional morphological differential diagnosis of mastocytosis in lymph nodes and recent advances in genetics of these systemic clonal mast cell proliferations. The latter not only outlines the oncopathogenesis but, in particular, also provides important prognostic and biological implications of this peculiar disease.

Abdomen↗
PubMed2006

[Frequency view on genome changes testing].

Laboratories dealing with human genome, both inherited and acquired changes, dispose with similar methods and technology. The spectrum of genetic tests is relatively broad and the number of mutations or variants tested differs substantially. Also the number of examinations carried out in individual laboratories varies. Data presented in the tables come from the year 2004 and indicate the number of examinations requested and number of positive results. Many laboratories mentioned in the registry CZDDNAL (http://www.uhkt.cz/lab_a_vysetreni/nr lab_dna_diag/dna_lab_db) perform the same tests but there is also a great number of tests carried out by only one laboratory. Reasons of the request, cost-effectiveness and clinical utility of genetic testing is being discussed.

Gene Frequency↗
PubMed2006

[Molecular genetic characterization of chronic lymphocytic leukemia aggressivity in Czech patients: a nucleotide variability of genes coding for heavy chain of immunoglobulin].

BACKGROUND: Chronic lymphocytic leukemia is a heterogeneous disease manifesting with a variable clinical course. It is evident from many studies, that the division into two main prognostic categories is possible on the basis of mutation status of the immunoglobulin heavy-chain gene. The objective of our work was to identify a presence or absence of IgVH gene mutations in B-CLL patients which are monitored or treated on hematological clinics and to determine the presence of individual D and J, subgenes in malignant population of B-cells. METHODS AND RESULTS: A nucleotide sequence of IgVH gene of neoplastic cells was analyzed by appropriate molecular-genetic methods. RNA/cDNA was collected from 358 patients and a spectrum of individual subgenes translocations was identified. Our results show that 56.3% of patients manifested an unmutated variable (VH) segment. It is expected from the published data that this group of patients will suffer from aggressive course of the disease and will exhibit a substantially shorter survival in comparison to patients possessing somatic hypermutations. An expanded population of leukemic B-cells showed increased occurrence of clones whose variable segments belong to three different families. VH3 alleles are the ones most frequently used. A frequency of unmutated alleles is prominently shifted into families with V I homology. The preferred "diversity and joining" segments are D3, D2 and JH 4 and JH 6. CONCLUSIONS: The analysis of heavy chain immunoglobulin gene after recombinant VH-D-J11 segments translocation belongs to a standard hematooncological investigation. The results are an important prognostic criterion for prediction of expected disease aggressivity and for a minimal residual disease monitoring.

Base Sequence↗
PubMed2004

[Dexrazoxane in patients with B-lymphomas or acute leukemias in the 2nd complete remission enables further therapy with cardiotoxic anthracyclines over recommended cumulative doses].

UNLABELLED: Daunorubicin (DNR) and doxorubicin (DOX) have significant antitumor activity in acute myeloid leukemias (AML) and non-Hodgkin's lymphomas (NHL) but their use is limited by their life-threatening cumulative dose related cardiotoxicity. It is generally recommended not to administer DOX or DNR to patients in doses greater than 500 mg/sqm or 700 mg/sqm, respectively. the aim of the study was to follow up cardiotoxicity and efficacy of DNR or DOX above these limits in the 2nd complete remission (CR) patients pretreated with anthracyclines when they were given 30 minutes after cardioprotective agent dexrazoxane (DRZ) in the ratio 1:10 of DZR. RESULTS: Two patients (54 and 53 years old) with mantle cell or diffuse large cell B-NHL, stage IV, who had relapsed after 6-8 cycles of classical CHOP therapy, reached their 2nd CR after 2-3 cycles of IDEA therapy (ifosfamide 1000 mg/sqm/day x 4, dexamethasone 30 mg/sqm/day x 4, etoposide 75 mg/sqm/day x 4, DOX 30 mg/sqm/day on days 1 and 3). Then they received further 3 cycles IDEA with DRZ 300 mg/sqm before every dose of DOX. After cumulative doses of DOX 600 mg/sqm and 700 mg/sqm these patients survived 12 months in their 2nd CR without significant signs of cardiotoxicity, even after their successful autologous peripheral stem cells transplantation. Their left ventricular ejection fraction (LVEF) remained above 60%. Six patients with AML in their 2nd CR were treated with consolidation cycles consisting of 10 high doses of cytosine arabinoside (2000 mg/sqm/12 hr) plus 2 doses of DNR 45 mg/sqm on the day 4 and 5. Two patients received cumulative doses corresponding to 1300 mg/sqm and 1000 mg/sqm of DNR, the other received DNR doses 550-850 mg/sqm. No signs of significant cardiotoxicity were observed in all 6 patients and their LVEF remained over 50%. One of two patients, transplanted with HLA-identical sibling bone marrow in her 2nd complete remission (CR), is still 8 years in her 2nd CR. Dexrazoxane enables to administer anthracyclines in doses over the recommended cumulative ones in pretreated patients with B-NHL or AML in their 2nd CR with the follow-up of their LVEF.

Acute Disease↗
PubMed2002

Interleukin-2 activation of haematopoietic stem cells.

BACKGROUND: Recent findings concerning the role of immunity in the eradication of residual malignant disease after autologous haematopoietic stem cell transplantation have led to extensive studies of T-cell and natural killer (NK) mediated anti-tumour effects. Interleukin 2 (IL-2) activation of autologous bone marrow (BM) or peripheral blood stem cells (PBSC) before transplantation is one of the methods of adoptive cell therapy. METHODS: Autologous BM of patients with chronic myelogenous leukaemia (n = 11) and PBSC of patients with multiple myeloma (n = 14) were activated by IL-2 in laboratory conditions with the aim of evaluating the feasibility of this method, the activation of T and NK cells, recovery of active progenitor cells, microbial contamination, and reduction of malignant cell content. RESULTS: Samples of BM (mean 2.6 x 10(6) cells) and PBSC (mean 10.3 x 10(6) cells) were cultured in complete culture medium with IL-2 (6000 Ul/ml) for 24 h. The recovery of CD34+ cells and CFU-GM was 82.5% and 51.5%, respectively, for BM, and 85% and 86%, respectively, for PBSC (mean values). No purging effect was detected by flow cytometry and a small decline in malignant cell contamination was observed by quantitative PCR in BM samples. No microbial contamination occurred during the sample processing. CONCLUSIONS: The described in vitro activation of BM and peripheral blood stem cells using IL-2 was evaluated as a safe and reliable method suitable for clinical application.

Bone Marrow↗
PubMed2001

[Activation of autologous hematopoietic stem cell transplants with interleukin-2].

BACKGROUND: Recent findings of the role of the immunity in eradication of residual tumour tissue after autologous transplantation rejection leading to extensive studies on T-cell mediated specific antitumor effects or nonspecific NL-cell mediated anticancer effects. We have evaluated on the methods of adoptive cell therapy--IL-2 activation of autologous graft in the preclinical conditions. In laboratory conditions we have manipulated with autologous grafts form patients suffering with chronic myelocytic leukemia and patients suffering with multiple myeloma. METHODS AND RESULTS: Autologous graft was activated with IL-2 during 24-hours cultivation period in X-Vivo 10 medium with heparine, glutamine and Dnase. Quality of grafts after cultivation, contamination and activation of T and NK cell were evaluated. No significant differences between IL-2 activated graft and control were found. Results of autologous graft quality (CD34+, CFU-GM) were comparable with already published results. Quality of final product allowed starting of clinical experimental trials. CONCLUSIONS: We have proved the possibility to use IL-2 activated autologous graft in the clinical conditions. Based on our preclinical results experimental clinical trials have been initiated in patients suffering from chronic myelocytic leukemia and multiple myeloma.

Cells, Cultured↗
PubMed2001

FGF-2 abnormalities in B cell chronic lymphocytic and chronic myeloid leukemias.

An elevated level of fibroblast growth factor-2 (FGF-2) in peripheral blood is considered to play a role in regulating the growth of leukemia cells. Here, we show that the level of plasma FGF-2 is increased in 54% of B cell chronic lymphocytic leukemias (B-CLL) and in 44% of chronic myeloid leukemias (CML). Notably, white blood cells (WBCs) from B-CLL patients contain 18, 22 and 24 kDa isoforms of FGF-2 whereas WBCs from CML patients contain only the 24 kDa isoform. Furthermore, as cultured B-CLL WBCs release 18 kDa FGF-2 into the medium, they constitute a potential source of FGF-2 in the blood. In a receptor binding assay, 125I-FGF-2 binds weakly to B-CLL WBCs, whereas the ligand binds more strongly to CML WBCs. Correspondingly, FGF-2 is unable to activate mitogen-activated protein kinase kinase (MEK) and its substrate, extracellular signal-regulated kinase (ERK), in B-CLL cells, whereas phosphorylation of both these cell growth-related kinases increases following treatment of CML WBCs. We conclude that B-CLL WBCs secrete FGF-2 with no apparent autocrine actions. In contrast, WBCs in CML bind FGF-2 provided by other FGF-2-hyperproducing cells and activate the MEK/ERK kinase cascade, possibly to modulate cell growth.

Adult↗
PubMed2000

Detailed mapping of methylcytosine positions at the CpG island surrounding the Pa promoter at the bcr-abl locus in CML patients and in two cell lines, K562 and BV173.

Chronic myelogenous leukemia (CML) is associated with a translocation of the protooncogene c-abl from chromosome 9 to chromosome 22, where it fuses to proximal exons of the bcr gene. The expression of the hybrid gene bcr-abl is regulated by the bcr promoter and results in a translation product with high tyrosine kinase activity. In most CML cases, one of two abl promoters (Pa) is nested within the bcr-abl transcription unit, but appears to be usually silent. Recently, de novo methylation of the Pa region and its correlation with disease progression were reported. As these previous studies were limited to the use of methylation-sensitive restriction endonucleases, our aim here was to obtain a complete map of methylcytosines and its variants in CML patients and in model cell lines. To achieve this, bisulfite conversion of cytosines (but not methylcytosines) to uracils in genomic DNA was employed. After modification, the region of interest was PCR-amplified and the products were cloned and sequenced. The results show methylation at a high level and in a homogenous pattern in the BV173 cell line, corresponding to the translocated abl alleles. Variant methylation observed in K562 cells correlates with multiple bcr-abl loci and an intact chromosome 9. Patients that were methylation-positive in restriction analysis showed sporadic and heterogenous occurrence of methylcytosines in bisulfite modification assays. Corresponding results were obtained using a quantitative Southern analysis of the extent of methylation. We conclude that restriction analysis combined with PCR is able to find rare cases of hypermethylation, e. g., for diagnostic purposes, but does not reflect the dominating level of methylation in Ph-positive cells.

Base Sequence↗
PubMed1999

[Diagnosis of cytomegalovirus infection with the polymerase chain reaction and antigenemia in patients after allogenic peripheral stem cell transplantation--comparison of 318 paired samples].

BACKGROUND: Cytomegalovirus (CMV) represents a serious infectious complication in patients after allogenic haematopoietic stem cell transplantation. Timely initiation of the therapy at the time of incipient active CMV infection (preemptive therapy) is an important prevention of CMV disease. It is not clear, what is the best indicator of this incipient CMV infection. METHODS AND RESULTS: The significance of the detection of incipient CMV infection by CMV-antigenaemia and DNA-viraemia was compared in this study. DNA-viraemia was detected by the non-nested polymerase chain reaction (PCR). The sensitivity of nested and non-nested PCR was also compared experimentally. We tested 318 blood samples for antigenaemia and DNA-viraemia. Six samples were significantly positive for PCR, no sample was significantly positive for antigenaemia. Timely initiation of therapy resulted in the rapid eradication of the incipient active CMV infection and clearance of DNA-viraemia. CONCLUSIONS: Non-nested PCR is a suitable and more reliable method for the monitoring of incipient active CMV infection and it is a good method for timely initiation of preemptive antiviral therapy.

Antigens, Viral↗
PubMed1997

[Diagnosis of mycotic infections in oncology patients using the polymerase chain reaction].

Diagnosis of mycotic infections is despite the immense effort devoted to this problem still very inaccurate. A new and promising method is the polymerase chain reaction, PCR, which theoretically can detect a single cell. In their original study the authors decided to develop a new method for the detection of fungi by PCR and to compare this examination with post-mortem findings. Thus it was possible to determine sufficiently reliably the sensitivity and specificity of the method. For the detection of fungi the authors selected the sequence coding for a small subunit of ribosomal RNA (18S rDNA). The method is able to detect the amount of DNA from some 10-100 cells. The sensitivity was 90% and the specificity 92%. The method is so far too laborious for common practice, its simplification would be however very useful.

Adult↗
PubMed1995

[Advances in the diagnosis of phenylketonuria with the introduction of direct detection of PAH gene mutation].

BACKGROUND: Phenylketonuria is as regards the genotype a very heterogenous disease. Successful prenatal and postnatal DNA diagnosis calls for knowledge of different mutations in a given population. The objective of the investigation was to introduce direct detection of 21 mutations in the gene for phenylalanine hydroxylase and to find the distribution and frequency of these mutations in the population of northern and southern Moravia. METHODS AND RESULTS: The authors analyzed a group of 95 patients where according to phenotypic classification classical phenylketonuria was involved which comprised 190 mutant alleles. The presence of mutations was assessed by means of a polymerase chain reaction of a Perkin Elmer DNA Thermal Cycler 480. From the total number of 21 mutations which were sought, 11 were identified in our population, which accounts for 80% of all mutations. It was revealed that mutation R408W is found in 55.3% of our patients. Twenty per cent of the mutations are still unknown. CONCLUSIONS: This investigation laid the foundations for direct DNA diagnosis of phenylketonuria in the Czech Republic. The results assembled in the Moravian region suggest that our population is as regards genotypes relatively homogenous. This gives great hope of successful prenatal diagnosis and postnatal genotype classification.

Genotype↗
PubMed1995

Phenylketonuria mutations and their relation to RFLP haplotypes at the PAH locus in Czech PKU families.

A detailed study of the mutant phenylalanine hydroxylase (PAH) gene from the eastern part of the Czech Republic (Moravia) is reported. A total of 190 mutant alleles from 95 phenylketonuria (PKU) families were analyzed for 21 prevalent Caucasian mutations and restriction fragment length polymorphism/variable number of tandem repeats (RFLP/VNTR) haplotypes. Eighty per cent of all mutant alleles were found to carry 11 mutations. The most common molecular defect was the mutation R408W (55.3%), with a very high degree of homozygosity (34.6%). Each of four other mutations (R158Q, R243X, G272X, IVS12nt1) accounted for more than 3% of PKU alleles. Rarely present were mutations IVS10nt546 (2.6%), R252W (2.6%), L48S (2.1%), R261Q (1.6%), Y414C (1.0%) and 165T (0.5%). Mutations that have been predominantly described in southern Europe (IVS7nt1, A259V, Y277D, R241H, T278N) were not detected. A total of 14 different mutant haplotypes were observed. Three unusual genotype-haplotype associations were identified (R158Q on haplotypes 2.3 and 7.8 and R252W on haplotype 69.3). There was a strong association between the mutation R408W and haplotype 2.3 (54.7%). Heterogeneity was found at mutations R408W (haplotypes 2.3 and 5.9), R158Q (haplotypes 4.3, 2.3 and 7.8) and IVS10nt546 (haplotypes 6.7 and 34.7). The molecular basis of PKU in the Moravian area appears to be relatively homogeneous in comparison with other southern and western European populations, thus providing a good starting point for prenatal diagnosis and early clinical classification.

Base Sequence↗
PubMed1993

Haplotype distribution at the phenylalanine hydroxylase locus in PKU families from the Moravian area of Czechoslovakia.

The analysis of 21 families affected with classical phenylketonuria (PKU) from the Moravian area of Czechoslovakia has revealed 12 different RFLP haplotypes. Nine and eight haplotypes were associated with the normal and with the mutant alleles, respectively. Most normal alleles are associated with haplotype 1 (42.9%). Almost 80% of all mutant alleles are confined within only three haplotypes (1, 2 and 4). There was a strong association between haplotype 2 and the Czech mutant alleles (61.9% of the mutant alleles compared with 4.8% of the normal alleles). There was linkage disequilibrium between this haplotype and the R408W mutation in exon 12. Two mutant haplotypes 7 were found and in both cases they were tightly linked with G272ter mutation. Our finding is in agreement with observations in other Eastern European countries. These data provide further support for the theories of the spread of the R408W mutation from east to west in European populations.

Czechoslovakia↗
PubMed1986

Monoclonal antibodies specific for pig serum and cell surface IgM.

Two monoclonal antibodies were prepared which react specifically with pig serum immunoglobulin and with the population of B lymphocyte-bearing surface immunoglobulin. Comparison of our monoclonal antibodies with reagents specific for gamma, mu and alpha immunoglobulin chains in double immunodiffusion and immunoelectrophoresis revealed that the monoclonal antibodies recognise IgM in pig serum and mu chain or mu chain-like molecules on B lymphocytes. The monoclonal antibodies, designated LIG 2 and LIG 4, reacted positively with adult pig sera but not with fetal or precolostral sera or with sera from other animal species. LIG 2 and LIG 4 reacted with 15 per cent of cells from the peripheral blood lymphocyte population, 20.2 per cent of spleen cells and 20 per cent of lymph node cells, but did not react with pig erythrocytes, granulocytes or cells isolated from thymus, or with the lymphocytes of other species. Positive reactions were also found on lymphatic and intestinal tissue sections. No genetic polymorphism was found in the pig population revealed by the monoclonal antibodies. The monoclonal antibodies LIG 2 and LIG 4 may be useful for studying the pig immune system, especially as a standard reagent for measuring pig serum IgM and for the identification of positive B lymphocytes.

Animals↗
PubMed1983

[Diagnosis of avian encephalomyelitis].

The diagnostic value of laboratory examination methods was assessed in the diagnosis of avian encephalomyelitis in seven to twenty-two days old chickens. Histological examination and immunofluorescent test are expedient methods meeting the requirements for timely application of infection-control measures. The agreement of histological examination with the over-all laboratory examination is 70 to 81% and the agreement of the immunofluorescence test is 76%. Bioassay on chickens followed by a histological examination appears to be the best method, providing results with the highest significance. However, it is lengthy, applicable to the necessary demonstration of a virus or to cases when the histological or immunofluorescence examinations are dubious. With the over-all laboratory evaluation the method shows agreement in 95 to 100% of cases. The diagnostic value of the method of virus isolation in chick embryos is reduced by the fact that intercurrent viruses (adenoviruses, IB and others) may be passaged at the same time.

Animals↗