Volume 47 (2001) No. 1
Translation Termination in Eukaryotes: from Simplicity to Complexity
L. L. KISSELEV............................................1
Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, Russia
Corresponding author: Lev L. Kisselev, Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, ul. Vavilova 32, Moscow, 117984, Russia. Tel.: (095) 1356009; Fax: (095) 135--1405; e-mail: kissel@imb.ac.ru.
Abstract.
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Articles
Effects of Tamoxifen and Melatonin on Mammary Gland Cancer Induced by N-methyl-N-nitrosourea and by 7,12-dimethylbenz(a)anthracene, Respectively, in Female Sprague-Dawley Rats
P. KUBATKA, B. BOJKOVÁ, K. MÔCIKOVÁ-KALICKÁ, M. MNÍCHOVÁ-CHAMILOVÁ, E. ADAMEKOVÁ, I. AHLERS, E. AHLERSOVÁ, M. ČERMÁKOVÁ................................5
Institute of Animal Physiology, Faculty of Science, P. J. Šafárik University, Košice, Slovakia
Corresponding author: Ivan Ahlers, Institute of Animal Physiology, Faculty of Science, P. J. Šafárik University, Moyzesova 11, 041 67 Košice, Slovakia. Tel.: +421 (95) 6224552; Fax: +421 (95) 6222124; e-mail: iahlers@kosice.upjs.sk.
Abstract.
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Cytotoxic Effects of Colicins E1 and E3 on v-myb-Transformed Chicken Monoblasts
J. ŠMARDA1, M. FIALOVÁ2, J. ŠMARDA, Jr.2.................................11
1Faculty of Medicine, and 2Faculty of Science, Masaryk University, Brno, Czech Republic
Corresponding author: Jan Šmarda, Department of Biology, Faculty of Medicine, Masaryk University, Joštova 10, 662 43 Brno, Czech Republic. Tel: +42 (05) 42126259; Fax: +42 (05) 42126200; e-mail: jsmarda@med.muni.cz.
Abstract.
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A Short Note on Micronucleoli in the Course of Terminal Maturation of Human Erythroblasts
K. SMETANA1, I. JIRÁSKOVÁ1, K. SMETANA, Jr.2, J. ČERMÁK1.........................14
1Clinical Department, Institute of Hematology and Blood Transfusion, Prague, Czech Republic
2Department of Anatomy, First Medical Faculty, Charles University, Prague, Czech Republic
Corresponding author: Karel Smetana, Institute of Hematology and Blood Transfusion, U nemocnice 1,
128 20 Prague 2, Czech Republic, Fax: 420 2 299821; e-mail: karel.smetana@uhkt.cz.
Abstract.
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Changes in Immunocytochemical Localization of Cytoskeletal Proteins in Boar Spermatozoa after
Acrosome Reaction Induced by Specific Cytoskeletal Inhibitors
K. DVOŘÁKOVÁ1, J. PALEČEK1, J. PĚKNICOVÁ2...................................18
1Department of Developmental Biology, Faculty of Science, Charles University, Prague, Czech Republic
2Laboratory of Biology and Biochemistry of Fertilization, Institute of Molecular Genetics, Academy of Sciences of the Czech Republic, Prague, Czech Republic
Corresponding author: Jana Pěknicová, Dept. of Biology and Biochemistry of Fertilization, Institute of Molecular Genetics, Academy of Sciences, Vídeňská 1083, 142 20 Prague 4, Czech Republic; e-mail: jpeknic@biomed.cas.cz.
Abstract.
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Short Communication
Analysis of Sister-Chromatid Exchanges and Micronuclei in Cultured Human Lymphocytes Treated with Insulin
N. DJELIC.....................................28
Department of Biology, Faculty of Veterinary Medicine, University of Belgrade, Belgrade,
Serbia, Yugoslavia
Corresponding author: Ninoslav J. Djelic, Department of Biology, Faculty of Veterinary Medicine, University of Belgrade, Bul. JNA 18, 11000 Belgrade, Serbia, Yugoslavia. Fax; Tel: + 381 11 685 936; e-mail:ndjelic vet.bg.ac.yu.
Abstract.
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Transforming Growth Factor-beta1 Induces junB mRNA Accumulation, G1-Phase Arrest, and pRb Dephosphorylation in Human Leukemia HL-60 Cells
J. PACHERNÍK1,2, K. SOUČEK2, A. HAMPL1,3, J. HOFMANOVÁ2,
A. KOZUBÍK2...............................................32
1Laboratory of Molecular Embryology, Mendel University Brno, Brno, Czech Republic
2Institute of Biophysics, Academy of Science of the Czech Republic, Brno, Czech Republic
3Developmental Biology Unit, Institute of Animal Physiology and Genetics, Academy of Sciences
of the Czech Republic, Brno, Czech Republic
Corresponding author: Alois Kozubík, Institute of Biophysics, Academy of Science of the Czech Republic, Královopolská 135, 612 65 Brno, Czech Republic. Tel.: + 420 (5) 41517182; fax: + 420 (5) 41211293; e-mail: kozubik@ibp.cz.
Abstract.
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Analysis of Paternal Alleles in Nucleated Red Blood Cells Enriched from Maternal Blood
I. HROMADNÍKOVÁ1, N. BENDUKIDZE2, M. MRŠTINOVÁ3, E. IVAŠKOVÁ2 .........36
12nd Clinic of Paediatrics and 3Department of Obstetrics and Gynaecology, University Hospital Motol, Prague, Czech Republic
2Department of Immunogenetics, Institute for Clinical and Experimental Medicine, Prague, Czech Republic
Corresponding author: Ilona Hromadníková, 2nd Clinic of Paediatrics, University Hospital Motol, V Úvalu 84, 150 06 Praha 5, Czech Republic. Tel.: +420 (2) 24432258; Fax: +420 (2) 24432220; e-mail: ilona.hromadnikova@lfmotol.cuni.cz.
Abstract.
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Translation Termination in Eukaryotes: from Simplicity to Complexity
L. L. KISSELEV
The last forty years of molecular biology and biochemistry were enormously rich in discoveries, which were not foreseen even by the most eminent scientists of that time. The findings of 1993--2000 profoundly enlarged our views on translation termination, clearly showing that our previous understanding was enormously oversimplified. Now the structural basis is created for much better insight into functions of termination factors. The story of translation termination in eukaryotes could be taken as an illustration of a general trend of molecular biology: 'From simplicity to complexity'. However, genuine knowledge requires that after this stage the third phase has to be reached, that is 'From complexity to clarity'. This is not yet achieved in translation termination and therefore makes this topic quite attractive for researchers.
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Effects of Tamoxifen and Melatonin on Mammary Gland Cancer Induced by N-methyl-N-nitrosourea and by 7,12-dimethylbenz(a)anthracene, Respectively, in Female Sprague-Dawley Rats
P. KUBATKA, B. BOJKOVÁ, K. MÔCIKOVÁ-KALICKÁ, M. MNÍCHOVÁ-CHAMILOVÁ, E. ADAMEKOVÁ, I. AHLERS, E. AHLERSOVÁ, M. ČERMÁKOVÁ
Chemopreventive effects of antioestrogen TAM and of MEL on NMU- or DMBA-induced mammary gland cancer, respectively, in female Sprague-Dawley rats were analysed. NMU was administered intraperitoneally in two doses each of 50 mg/kg b.w. between 46th-57th postnatal days. DMBA was given by gavage in one dose (20 mg per animal) between 50th-54th postnatal days. The treatment with MEL began 12 days and the treatment with TAM 10 days before carcinogen administration; both chemopreventive substances were administered until the end of the experiment (24 weeks after carcinogen application). TAM was administered subcutaneously twice a week in a dose 2.5 mg/kg b.w. MEL was given in ta DMBA-induced mammary carcinogenesis it significantly lowered the tumour volume (2.70 + 0.81 cm3 vs. 0.90 + 0.33 cm3) and lengthened (non-significantly) the latency period (by 12 days). The weight gain of animals in both NMU and DMBA models and relative uterus weight in the NMU model were lower in the groups treated with TAM and TAM+MEL as compared to the control group and the group treated with MEL. Evaluation of the combined effect of TAM+MEL was not possible due to total suppression of carcinogenesis by TAM.
TAM and TAM+MEL are highly effective agents in rat mammary carcinogenesis prevention, but the side effects of TAM in humans limits its use in clinical oncology.
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Cytotoxic Effects of Colicins E1 and E3 on v-myb-Transformed Chicken Monoblasts
J. ŠMARDA, M. FIALOVÁ, J. ŠMARDA, Jr.
Colicins show a considerable cytostatic activity that is much less known and understood than their killing activity targeting bacteria of the Enterobacteriaceae family. In this communication, the cytotoxic effects of colicins E1 and E3 on v-myb-transformed chicken monoblasts BM2 are presented. We detected clear reduction of viable cell number induced by colicins E1 and E3, occurring without apparent changes in cell cycle profiles. The level of inhibition was proportional to the colicin concentration within the limits of 0.5-1.25 mikrog/ml. This result documents that colicins produced by Enterobacteriaceae exert their cytotoxic effects on leukemic cells.
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K. SMETANA1, I. JIRÁSKOVÁ1, K. SMETANA, Jr.2, J. ČERMÁK
The incidence of micronucleoli in the course of terminal differentiation of human erythroblasts were
studied by the cytochemical procedures for demonstration of RNA and characteristic proteins of interphase AgNORs. The last dividing stages of the erythroid lineage - polychromatophylic erythroblasts - characterized by the presence of micronucleoli exhibit significantly larger values of the nucleolar coefficient in specimens stained for AgNOR proteins than in those stained for RNA. In addition, both these and terminal non-dividing nucleated stages of the erythroid lineage - orthochromatic erythroblasts - possessed micronucleoli after staining for RNA in a much smaller percentage of cells than after staining for AgNOR proteins. Thus, both these observations indicate that micronucleoli in the course of terminal maturation of erythroblasts apparently lose the nucleolar RNA detectable by the light microscopic cytochemistry. In addition, the silver-stained micronucleoli - nucleolar remnants - were also noted in erythroblasts expelling the nucleus.
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Acrosome Reaction Induced by Specific Cytoskeletal Inhibitors
K. DVOŘÁKOVÁ, J. PALEČEK, J. PĚKNICOVÁ
results of confocal and electron microscopy also demonstrate visible changes of actin-, tubulin-
and spectrin-containing structures after the AR. Our data indicate that specific cytoskeletal inhibitors influence the AR and they prove the role of cytoskeletal proteins in this process.
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Analysis of Sister-Chromatid Exchanges and Micronuclei in Cultured Human Lymphocytes Treated with Insulin
N. DJELIC
Insulin is an anabolic hormone that may facilitate development of malignant diseases in various susceptible tissues due to stimulation of mitotic divisions. In this work, an evaluation of mitogenic and genotoxic effects
of human recombinant insulin has been performed in cultures of human peripheral blood lymphocytes. Genotoxic effects were studied by the following test systems: (1) in vitro SCE test, and (2) cytokinesis-blocked micronucleus assay. The obtained results indicate that insulin stimulates mitotic division at an optimal concentration of 10-8 M. On the other hand, insulin has not exhibited genotoxic properties under experimental conditions in this investigation.
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J. PACHERNÍK, K. SOUČEK, A. HAMPL, J. HOFMANOVÁ,
A. KOZUBÍK
for the development of myeloid lineage is still questionable. In this study three components of early response to TGF-beta1 treatment were investigated in human promyelocytic leukemia HL-60 cells. Changes in junB mRNA accumulation and pRb dephosphorylation were accompained by accumulation of cells in G1 phase
of the cell cycle. Time dependence of these changes may implicate mutual cooperation of the pRb and JunB in the cell cycle control. It can be concluded that, although myeloid HL-60 cells are known to require rather complex cytokine stimulation to fully differentiate, they clearly possess the ability to respond to TGF-beta1.
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I. HROMADNÍKOVÁ, N. BENDUKIDZE, M. MRŠTINOVÁ, E. IVAŠKOVÁ
The purpose of our study was to identify paternal alleles in NRBC enriched from maternal peripheral blood for detection of the presence of foetal cells in the maternal circulation and to establish a reliable non-invasive method which should allow following genetic testing. For enrichment of foetal cells from peripheral maternal blood we combined Ficoll-Paque density gradient centrifugation and MACS. Maternal leukocytes were firstly depleted using anti-CD14 and anti-CD45 microbeads. NRBC were sorted from the CD14-/CD45- fraction by positive selection using CD71 microbeads. Paternal alleles in the CD14-/CD45-/CD71+ fraction were indicated by the PCR method using HLA (DRB1, DQB1,DQA1) and Polymarker System (LDLR, GYPA, HBGG, D7S8, GC) as genetic markers. Different paternal alleles of studied 8 loci were detected in 13 out of 19 samples of cells enriched from maternal peripheral blood between the 13th and 36th week of gestation. Our results demonstrate that foetal cells enriched from maternal peripheral blood may be used as a source of foetal DNA for prenatal diagnosis, paternity testing and other application.
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