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R Brdicka

Publications and source records attributed to R Brdicka.

At least 19 recordsLinked to original sources
PubMed2001

[Gene therapy of hemophilia--the next disappointment?].

Since the very beginning the evident target of gene therapy were monogenic disease, though the number of applicated protocols in the treatment by oncologic processes has become much higher now. Several clinical studies, using viral vectors or direct transfer of plasmids containing sequences of human factor VIII, from which the central part (domain B) had been deleted gave satisfactory results concerning the transfer effectivity. On the other hand the amount of factor VIII produced in recipients was decreasing and was no more detectable after one year after administration of transfected fibroblasts.

Factor VIII↗
PubMed2000

[Gene expression in white blood cells in chronic myeloid leukemia].

BACKGROUND: The new technologies that have the DNA laboratory over recent years and the general progress in knowledge of the human genome, have allowed the simultaneous observation of the activity of a large number of genes. Chronic myeloid leukemia is characterized with abnormal tyrosine kinase activity of the fused bcr/abl gene, which is most often product of translocation between chromosomes 9 an 22. It is as yet unknown whether this is the only and sufficient cause of the disease, or whether other supporting and co-active abnormalities exist. It is also not yet clear whether an increase of proliferating activity or reduced programmed cell death plays the dominant role. The aim of this study was to make further steps in resolving the question as to which of these hypotheses fits better. METHODS AND RESULTS: Membrane macroarrays (Clontech 7742-1: Human Cancer cDNA Expression Array with 588 gene probes) were used throughout the study, on which cDNA reverse-transcribed from total RNA in turn isolated from peripheral white blood cells and labelled with 32P was hybridized. Cells obtained from 5 patients with confirmed diagnoses by cytogenetic and molecular (bcr/abl) analyses, but who had not yet been treated by chemotherapy, were the source of the material. In some cases mononuclears and granulocytes were also isolated by Ficoll-Paque centrifugation. Radioactivity was detected by autoradiography or by a Phosphorimager (Fujifilm FLA-2000). Comparison with normal gene expression (healthy donor) was made by subtraction using Clontech AtlaImage 1.5 software. Although changes of expression of identical genes were not observed in all of patients examined, the majority of them were concordant. Values at least double those of the controls applied to the activity of c-jun N-terminal kinase, MMP-8, MMP-9, integrin alpha E, integrin beta and PDGF, whereas the expression of ZAP-70, IRF1, MCL-1, STAT 5B, RARA, CDC25B, RPSA, TNFR decreased. Increases of PCNA, MMP-17, CD59, rho G, CRAF1 and PIG7 or decreases of notch, caspase 8, caspase 4, interleukin 6 receptor, rho B and TIMP1 were observed only in some cell samples. CONCLUSIONS: It seems that some maturation processes and transmembrane signalling are blocked, as well as the effectors of apoptosis. On the other hand, the reduced activity of ZAP-70, IRF1 and MCL-1 also indicated that proliferation breaks were weakened. The involvement of both processes-released replication and ineffective apoptosis--was evident; the problem of bcr/abl gene fusion being the necessary first and sufficient step on the way towards developing chronic myeloid leukemia, however, remained unresolved.

Fusion Proteins, bcr-abl↗
PubMed2000

[The human genome--chromosome 22].

Once dare, today casual, the project of the human genome basic structure analysis celebrated its first major accomplishment when the almost complete sequence of the twenty-second chromosome was published. Though the chromosome represents only hardly more than 1.5% of the total genomic DNA, it is comparatively rich from the point of gene content (545 hitherto identified gene sequences) and it is important from the medicinal point of view. Among pathologic states resulting from its impaired function inborn heart and major vessel defects, mental disorders, and malignities are rated.

Chromosome Mapping↗
PubMed2000

Prediction and reversion of post-transplant relapse in patients with chronic myeloid leukemia using mixed chimerism and residual disease detection and adoptive immunotherapy.

In the prospective study, we examined hematopoietic mixed chimerism (using polymerase chain reaction (PCR) of variable number of tandem repeat-VNTR sequences) and minimal residual disease (MRD) status (using qualitative and in the case of positivity quantitative reverse transcriptase polymerase chain reaction (RT-PCR) for the BCR/ABL fusion mRNA) in serial peripheral blood samples taken from 25 patients after bone marrow transplantation (BMT) for chronic myeloid leukemia (CML). Increasing mixed chimerism in correlation with increasing signal of MRD was detected in 10 patients. In two patients mixed chimera status and BCR/ABL rearrangement led to hematologic relapse, in five patients molecular relapse was followed by reappearance of Ph chromosome and three patients developed molecular relapse only. Adoptive immunotherapy-donor lymphocyte infusion (DLI), interferon (INF) and discontinuation of post-transplant immunosupression-separately or in different combinations was used in nine patients with molecular, cytogenetic or hematologic relapse of CML. The results demonstrate that significant response at the molecular level can be achieved for a majority of CML patients and that using of all forms of adoptive immunotherapy controlled by MC and MRD is more efficient in patients treated in early molecular relapse-with minimal disease burdens.

Adolescent↗
PubMed2000

Detailed monitoring of hematopoietic chimerism in a child treated by adoptive immunotherapy for high risk of relapse after BMT for acute myeloid leukemia.

We report a case of a 13-year-old boy who was transplanted for relapse of acute myeloid leukemia (AML). A detailed study of hematopoietic chimerism was performed using polymerase chain reaction (PCR) of variable number of tandem repeats (VNTR) at very short time intervals. We used discontinuation of post-transplant immunosuppression and donor lymphocyte infusions (DLI) in order to prevent leukemia relapse that was indicated by a progressive increase in autologous hematopoiesis. Despite the fact that the boy relapsed 10 months after BMT, we could see a significant influence of adoptive immunotherapy on the mixed chimerism status during the post-transplant period.

Acute Disease↗
PubMed2000

Patterns of male-specific inter-population divergence in Europe, West Asia and North Africa.

We typed 1801 males from 55 locations for the Y-specific binary markers YAP, DYZ3, SRY10831 and the (CA)n microsatellites YCAII and DYS413. Phylogenetic relationships of chromosomes with the same binary haplotype were condensed in seven large one-step networks, which accounted for 95% of all chromosomes. Their coalescence ages were estimated based on microsatellite diversity. The three largest and oldest networks undergo sharp frequency changes in three areas. The more recent network 3.1A clearly discriminates between Western and Eastern European populations. Pairwise Fst showed an overall increment with increasing geographic distance but with a slope greatly reduced when compared to previous reports. By sectioning the entire data set according to geographic and linguistic criteria, we found higher Fst-on-distance slopes within Europe than in West Asia or across the two continents.

Africa, Northern↗
PubMed2000

Genes involved in the destruction of leukaemic cells by induced photosensitivity.

Gene expression changes were observed in the HEL and HL-60 cell lines after the stimulation of protoporphyrin IX synthesis by ALA administration and photodynamic process induction. Isolated ribonucleic acids were radiolabelled by reverse transcription, and the cDNA obtained was hybridized to membrane macroarrays (Clontech 7742-1) containing 588 gene probes. Besides changes in the activity of genes supposed to be involved in the programmed cell death and DNA reparation processes, increased or diminished transcription activity was also observed in several other genes; the reason for this phenomenon was not clear. The activation of programmed-cell-death genes appeared after the ALA load application, indicating the toxic effect of ALA. The gene expression changes observed in the two cell lines differed substantially, only a few of them were common for both cell lines.

Aminolevulinic Acid↗
PubMed1999

Frequencies of HLA-DRB1, -DQB1 and -DPB1 alleles in Czech population.

The frequencies of phenotypes, alleles and allelic subtypes of DRB1 and DQB1 HLA loci in 420 unrelated individuals from the Czech population were determined. The frequencies of DPB1 alleles of the HLA locus were determined in 92 individuals. The assays were performed using the polymerase chain reaction (PCR) method or the restriction fragment length polymorphism (RFLP) analysis. The most frequent DRB1 allele was *07, the most frequent DQB1 allele was *03 and the most frequent DPB1 allele detected was *04. These assays define the extent of polymorphism of the HLA system and are useful for determining the selection strategy of HLA-identical donor-recipient pair suitable for bone marrow transplantation.

Alleles↗
PubMed1998

[Bird's eye view of laboratories--report on symposia].

"Biochips" technology starts entering DNA laboratories and not only as prototypes, that show fascinating increase in effectivity which can change our nearest future. Practically all processes used in DNA laboratories are to be involved. Hybridization reaction is the most often used principle in microchips, but already polymerase chain reaction (PCR) has been miniaturized to the microchip level and also separation of blood cells. Function of these newly developed microdevices in being verified by solving practical problems in diagnostics.

Bioreactors↗
PubMed1998

[Human cloning. (Do we have too much courage or not enough?) New perspectives in medicine].

Cloning mammals including man has become a real possibility of these years. The result obtained in sheep and cattle demonstrated that technical problems have been solved and now other disciplines--philosophy, ethics, law etc are confronted with this challenge. On one side we have to look for all risks and adopt adequate responsibility, on the other side to consider medical benefits by solving problems with reproduction, organ transplantation and inherited diseases. As the last but not least we have to establish formal rules and to introduce the conception into all disciplines involved, in the first place into genetics. Trying to contribute to the adaptation of formal genetics to the new situation we propose to link the donor and the recipient of the nucleus with a triple line in pedigree schemes.

Animals↗
PubMed1998

[DNA polymorphism, allogenic bone marrow transplantation and peripheral cell chimerism].

BACKGROUND: Bone marrow transplantation or transplantation of peripheral stem cells is an effective treatment of a number of diseases. Its increasing success and expanding use in associated with the development of molecular diagnostic methods which enable to follow up the graft from its engraftment in a recipient and then during the whole posttransplantation period at the level extremely small numbers of cells. METHODS AND RESULTS: In peripheral blood of patients, genotypes of the following loci were examined by polymerase chain reaction (PCR): APOB, COL2A1, D17S20, D1S80, HVR/1G, SRY and AMXY. Technique of restriction analysis was used for loci DXYS20 and DXYS75. 1. The first signs of donor bone marrow activity were observed in 50% of patients already at the beginning of the second week after transplantation, while in the second half of patients increasing number of donor cells in peripheral blood was noticed in the second and third week. 2. Engraftment with full and permanent substitution of own bone marrow without presence of recipients cells in peripheral blood--complete chimerism--was achieved only in a part of patients (cca 50%). 3. Peripheral blood of other patients did not contain only donor cells but also recipients cells--mixed chimerism. With regard to its onset, the authors have divided mixed chimerism into early and late, taking into account that some patients can develop both types. In patients under study, early chimerism was found more frequently, which apparently resulted from a shorter period of observation of lately transplanted patients. 4. In cases of oncohaematologic patients, which allowed to study specifically the presence of a pathologic clone, the follow-up of chimerism enabled to distinguish between relapse of the original disease and "biologic" recovery--resurrection of original disease-free haematopoiesis. 5. Regression of mixed chimerism was supposed to be the result of treatment focused at the original disease (CML), in some patients, however, it was a spontaneous process. CONCLUSIONS: Follow-up of cellular chimerism in transplanted patients by means of molecular genetic methods provides substantial information about patient's shape which can be utilized it is necessary to decide on treatment procedures. For this reason it is desirable that examination of chimerism by molecular methods should form integral part of care of these patients.

Adolescent↗
PubMed1998

Network analyses of Y-chromosomal types in Europe, northern Africa, and western Asia reveal specific patterns of geographic distribution.

In a study of 908 males from Europe, northern Africa, and western Asia, the variation of four Y-linked dinucleotide microsatellites was analyzed within three "frames" that are defined by mutations that are nonrecurrent, or nearly so. The rapid generation and extinction of new dinucleotide length variants causes the haplotypes within each lineage to diverge from one another. We constructed networks of "adjacent" haplotypes within each frame, by assuming changes of a single dinucleotide unit. Two small and six large networks were obtained, the latter including 94.9% of the sampled Y chromosomes. We show that the phenetic relationships among haplotypes, represented as a network, result largely from common descent and subsequent molecular radiation. The grouping of haplotypes of the same network thus fits an evolutionarily relevant criterion. Notably, this method allows the total diversity within a sample to be partitioned. Networks can be considered optimal markers for population studies, because reliable frequency estimates can be obtained in small samples. We present synthetic maps describing the incidence of different Y-chromosomal lineages in the extant human populations of the surveyed areas. Dinucleotide diversity also was used to infer time intervals for the coalescence of each network.

Africa, Northern↗
PubMed1996

[Determination of biological paternity yesterday and today].

The paper deals with methodical development of expertise in cases of disputed paternity. Presently used approaches to paternity testing were introduced following deeper understanding of heredity of human features as well as development of new methods of their studying. While the genetic characterization of individuals tested was till recent time limited to the level of gene products, in the present also direct molecular genetic analysis of their genome is possible. The most frequently used molecular genetic technique is Polymerase Chain Reaction (PCR) which leads to multiplication of chosen hypervariable regions of DNA followed with direct with following direct detection of polymorphic alleles. Examination of several DNA polymorphisms provides an exclusion of all falsely accused men and in opposite cases a practical proof of parenthood. That is the reason why the world-wide trends of forensic medicine tend to consecutive replacement of all procedures use until now with methods of molecular genetics.

DNA Fingerprinting↗
PubMed1996

HLA class II gene frequency in a Czech Population.

In a sample of 212 healthy, unrelated individuals of a Czech (Central Bohemian) population, the phenotype and allele frequencies of HLA-DRB1 and -DQB1 loci were determined. DNA typing technique used was the restriction fragment length polymorphism (RFLP) analysis. The restriction enzymes were TaqI and HindIII and specific DRB1 and DQB1 probes were applied. The most frequent DRB1 and DQB1 alleles found were DRB1*11 and DQB1*06, their respective frequencies being 0.1698 and 0.2594.

Alleles↗
PubMed1995

[The human genome--chromosome Y].

The Y chromosome, the only chromosome present only in the male karyotype, is one of the smallest human chromosomes. Its content of protein-forming genes is, as compared with other chromosomes, greatly reduced and if we omit the part homologous with the X chromosome it is really minimal. For normal development the area occupied by locus TDF or SRY can be considered essential. The antigenic locus HY is also associated with male sex. Well known are also the amelogenin locus which is in the pseudoautosomal area, the locus conditioning Kallmann's syndrome and locus ASMTY for hydroxyindole-O-methyltransferase--the last enzyme of the metabolic route to the pineal hormone melatonin. With regard to the presence of many highly polymorphous areas the Y chromosome is predestined for population studies where it supplements aptly investigations of the mitochondrial genome, and for investigations of cellular chimerism after allogeneic transplantations.

Chromosome Mapping↗
PubMed1995

[The human genome--chromosome 22].

The 22nd chromosome is known mainly due to chromosome (Philadelphia) which is its derivative-a typical cytogenetic sign of chronic myeloid leukaemia (CML). The molecular genetic finding in these patients is the fused gene which developed by combination of the 3' part of the oncogene ABL from chromosome 9 and 5' part of the gene which developed by combination of the 3' part of the oncogene ABL from chromosome 9 and 5' part of the BCR "gene". The product of the gene retains the original kinase activity (ABL) which is even higher. Detection of BCR/ABL is an important diagnostic aid whic makes it possible to investigate residual diseases in patients after intensive treatment and transplantation of bone marrow and early detection of possible relapses. Among locuses of the 22nd chromosome the author mentions also the locus of the second one of the light immunoglobulin chains-lambda, incl. some of its "related" genes, the group of crystalline locuses (CRYB), the locus of the beta-chain of the GM-CSF receptor, the myoglobin locus (MB) and finally locus NF2 of central neurofibromatosis-bilateral neurinoma of the acoustic nerve.

Chromosome Mapping↗