Volume 43 (1997) No. 2

Volume 43 (1997) No. 2

Review

Factors Influencing the Preimmune Antibody Repertoire

P. KRAJ.........53-61

Laboratory of Immunobiology, Institute of Immunology and Experimental Therapy, Wroclaw, Poland

Corresponding author: Piotr Kraj, Laboratory of Immunobiology, Institute of Immunology and Experimental Therapy, ul. Czerska 12, 53-114 Wroclaw, Poland

Abstract.

Articles

Production of env Deficient Rous Sarcoma Virus (RSV) Early after Infection

HIROTO HARA, HANKYEL T. PARK, MITSUHIRO FUJIHARA, AKIRA KAJI .........63-70

Department of Microbiology, University of Pennsylvania School of Medicine, Philadelphia, PA, USA.

Corresponding author: Hiroto Hara, Department of Mcrobiology, University of Pennsylvania School of Medicine, Philadelphia, PA, 19104 USA. Tel. (215) 898-6524, Fax (215) 573-2221.

Abstract

Drosophila melanogaster, Vicia faba and Arabidopsis thaliana Short-term Bioassays in Genotoxicity Evaluation of Air and Soil Samples from Localities Surrounding Two Industrial Factories in the Czech Republic

K. CHROUST*, P. KUGLÍK*, J. RELICHOVÁ*, I. HOLOUBEK**, J. ÈÁSLAVSKÝ**, R. VESELSKÁ*, M. RYŠKOVÁ*, J. BENEDÍK*..........71-78

*Department of Genetics and Molecular Biology, and

**Department of Environmental Studies, Faculty of Sciences, Masaryk University, Brno, Czech Republic

Corresponding author: Karel Chroust, Department of Genetics and Molecular Biology, Faculty of Sciences, Masaryk University, Kotláøská 2, CZ-611 37, Brno. Tel. 0042-5-41129546, Fax 0042-5-41211214.

Abstract

The Cell Cycle Positions Influence DNA Migration as Measured with the Alkaline Comet Assay in Stimulated Human Lymphocytes

J. ŠALAGOVIÈ*, A. MAES**, U. VAN GORP**, L. VERSCHAEVE**, I. KALINA*..........79-82

* Institute of Medical Biology, Medical Faculty, Šafárik University, Košice, Slovakia

** Vlaamse Instelling voor Technologisch Onderzoek (V.I.T.O.), Division of Environmental Research, Mol, Belgium

Corresponding author: Ján Šalagoviè, Institute of Medical Biology, Medical Faculty, Šafárik University, Tr. SNP 1, 040 66 Košice. Slovakia.

Abstract

Relationships between the Structure, Cytotoxicity and Hydrophobicity of Quinazoline Derivatives by QSAR S.

JANTOVÁ*, Š. BALÁŽ**, Š. STANKOVSKÝ***, K. ŠPIRKOVÁ***, V. LUKÁÈOVÁ**..........83-89

*Department of Biochemistry and Microbiology,

**Department of Biochemical Technology and

***Department of Organic Chemistry, Faculty of Chemical Technology, Slovak Technical University, Bratislava, Slovakia

Corresponding author: Soòa Jantová, Department of Biochemistry and Microbiology, Faculty of Chemical Technology, Slovak Technical University, Radlinského 9, 812 37 Bratislava, Slovakia.

Abstract

Short Communication

Variability of the Adaptive Response to Low Dose Radiation in Peripheral Lymphocytes of Twins and Unrelated Donors

I. KALINA, G. NÉMETHOVÁ........91-95

Department of Medical Biology, School of Medicine, Šafarik University, Košice, Slovak Republic

Corresponding author: Ivan Kalina, Department of Medical Biology, School of Medicine, Šafarik University, Tr. SNP 1, 040 66 Košice, Slovak Republic.

Abstract

Abstracts.

Factors Influencing the Preimmune Antibody Repertoire

P. KRAJ

Preimmune antibody repertoire is not a statistical representation of all germline VH, D, JH and VL, JL segments encoding heavy and light chains, respectively. The antibody repertoire is biased towards a fraction of VH and VL gene segments in fetal/neonatal as well as adult life. The repertoire bias starts at the surface Ig-negative pre-B cells and persists throughout B-cell ontogeny. Antigen-independent processes like preferential rearrangements of VH, D and JH segments and pairing of the heavy and surrogate light chain operate at the surface Ig-negative pre-B cell stage. Subsequently B cells may be subject to self-antigen selection based on the specificity of their surface receptors.

Back to content.

Production of env Deficient Rous Sarcoma Virus (RSV) Early after Infection

HIROTO HARA, HANKYEL T. PARK, MITSUHIRO FUJIHARA, AKIRA KAJI

Production of defective virus particles during the early stage of Rous sarcoma virus (RSV) infection of chicken embryo fibroblasts (CEF) was examined. RSV harvested 2 days post infection (2pi) had 10 to 30 times lower specific infectivity (focus forming units/unit reverse transcriptase activity) than 5pi harvest. Virus particles produced on day 2 contained less env proteins than particles harvested on day 5. The amount of other viral proteins was equal in particles harvested on day 2 and day 5. Analysis of infected cells revealed that these cells synthesized less env proteins on day 2 than on day 5. RSV RNA in infected cells was spliced normally on day 2. Infection at a low multiplicity of infection (moi) prolonged the production of defective particles. When infection was initiated by a low moi (0.01), particles harvested on day 5 had the same characteristics as 2pi particles after infection with a high moi (1.0). We conclude that the low infectivity of early harvest is due to the reduced amount of env proteins in virus particles, which is a consequence of the reduced env protein synthesis.

Back to content.

K. CHROUST*, P. KUGLÍK*, J. RELICHOVÁ*, I. HOLOUBEK**, J. ÈÁSLAVSKÝ**, R. VESELSKÁ*, M. RYŠKOVÁ*, J. BENEDÍK*

The Somatic Mutation and Recombination Test (SMART) in wing cells of Drosophila melanogaster, the Vicia faba cytogenetic tests -- Sister Chromatid Exchange (SCE) and Micronucleus Test (MN) --, and the Müller's test for gametic mutations in Arabidopsis thaliana were used for genotoxicity testing of environmental samples of pollutants from the surroundings of LACHEMA chemical factory (Brno, Czech Republic) and DEZA factory in Valašské Meziøíèí (Moravia, Czech Republic). Tested soil and air samples were taken from the near vicinity of both factories. The surroundings of both localities are heavy loaded by exhalation of chemicals from the factories. Chemical analyses of the 16 Polycyclic Aromatic Hydrocarbons (PAHs) according to the United States Environmental Protection Agency (US EPA) list of priority pollutants and heavy metals were performed in both soil and air samples. The Drosophila wing spot test was positive in 70.6% of the tested samples, the Vicia sister chromatid exchange test in 62.5%, and the Arabidopsis Müller test in 58.9%. The micronucleus Vicia faba test was quite insensitive in tested environmental samples. The concordance between SMART and SCE was 62.5%, between SMART and Müller test was 76.5%, and between Müller test and SCE was 100%. Total concordance of these three tests was 79.7%. Müller test for gametic mutation in Arabidopsis thaliana and cytogenetic SCE test in Vicia faba seem to be quite sensitive and convenient plant bioassays for assessing the mutagenic potential of environmental agents, when compared to the SMART test in Drosophila melanogaster.

Back to content.

The Cell Cycle Positions Influence DNA Migration as Measured with the Alkaline Comet Assay in Stimulated Human Lymphocytes

J. ŠALAGOVIÈ*, A. MAES**, U. VAN GORP**, L. VERSCHAEVE**, I. KALINA*

Virtually any eukaryotic cell can be processed for analysis of DNA damage using the comet assay. The most commonly examined human cells are lymphocyte populations. However, many parameters can affect the response of lymphocytes to the assay in terms of the ability to detect damage. The response of cultivated lymphocytes in the comet assay indicated cycle dependent differences. The cell cycle position has been shown to affect the results obtained using both the alkaline and neutral assays.This is primarily a reflection of the complications of including S-phase DNA. In the alkaline assay, replicating structures are interpreted as strand breaks when denatured, increasing the level of detectable damage. We performed the alkaline comet assay to detect differences in the extent of DNA in stimulated human lymphocytes collected at different sample times after mitogen stimulation. Our results clearly indicate that proliferating lymphocytes have a greater migration of DNA (measured with the comet assay as DNA damage) than quiescent lymphocytes. The lymphocytes collected at 36, 42, and 48 h after mitogen stimulation showed a significantly increased extent of DNA migration in comparison to the lymphocytes collected at 0 and 24 h after stimulation. It, probably, can be explained by the higher frequency of the S phase cells in lymphocyte populations collected at 36, 42, and 48 h. Sites of active DNA replication during the S phase behave like single-strand breaks when denatured in alkali, and their presence may result in a significant increase of the tail moments in S phase cells.

Back to content.

Relationships between the Structure, Cytotoxicity and Hydrophobicity of Quinazoline Derivatives by QSAR S.

JANTOVÁ*, Š. BALÁŽ**, Š. STANKOVSKÝ***, K. ŠPIRKOVÁ***, V. LUKÁÈOVÁ**

Cytotoxicities of 93 quinazoline derivatives against HeLa cells have been determined as the isoeffective concentrations inhibiting, after a single dose, the protein synthesis to 50% of the control amount after 48 h incubation. The dependence of cytotoxicity on hydrophobicity of the studied derivatives has been described using a previously published model-based approach. The studied derivatives are classified into nine classes each forming a smooth hydrophobicity-cytotoxicity curve. Owing to the acceptable agreement between the model and the data it can be inferred that: (1) the compounds except two derivatives bind to the receptors with approximately the same affinity; (2) the criterion for the classification is the different rate of metabolism. The results represent a basis for a rational development of more potent quinazoline derivatives.

Back to content.

Variability of the Adaptive Response to Low Dose Radiation in Peripheral Lymphocytes of Twins and Unrelated Donors

I. KALINA, G. NÉMETHOVÁ

To assess the genetic control of the induction of the adaptive response after low-dose ionizing radiation, the frequencies of chromosome aberrations were evaluated in four pairs of monozygotic twins, two pairs of dizygotic twins, and in nine unrelated individuals. Stimulated cells were exposed to adaptive dose of 5 cGy gamma rays at 24 h and challenge dose of 150 cGy gamma rays at 42 h. Cells were fixed at 48 h and chromatid and isochromatid breaks were evaluated. The adaptive response was found in two pairs of monozygotic twins, while in the other two pairs was not. Individual differences in adaptive response between members of monozygotic twins were very small. In contrast, the variability in the adaptive response between the members of dizygotic twins was much greater and was similar to that observed in the unrelated donors. The results confirmed that heterogeneity in the adaptive response after exposure to low-dose gamma rays was controlled genetically to a considerable exent.

Back to content.