The Dose- and Time-Dependent Cytotoxic Effect of Graphene Nanoplatelets: In Vitro and In Vivo Study.

Graphene-based nanomaterials received attention from scientists due to their unique properties: they are highly conductive, mechanically resistant and elastic. These materials can be used in different sectors of society from electronic energy storage in industry to biomedical applications. This study evaluates the influence of graphene nanoplatelets in vitro and in vivo.

Chromosomal aberrations in environmentally exposed population in relation to metabolic and DNA repair genes polymorphisms.

The capital city of Prague is one of the most polluted localities of the Czech Republic. Therefore, the effect of exposure to carcinogenic polycyclic aromatic hydrocarbons (c-PAHs) adsorbed onto respirable air particles (<2.5mum) on chromosomal aberrations was studied in a group of policemen (males, aged 22-50 years) working in the downtown area of Prague and spending daily >8h outdoors (N=53).

Human biomonitoring system in the Czech Republic.

The human biomonitoring (HBM) is an integral part of Environmental Health Monitoring System in the Czech Republic since 1994. Selected biomarkers of the internal dose (heavy metals, PCBs) and cytogenetic analysis of peripheral lymphocytes as a biomarker of the exposure/effect to/of environmental genotoxic factors are systematically followed up in the blood and urine of adults (blood donors), in children aged 8 to 10 years, and in the breast milk of nursing mothers. Selected outputs documented the declining trend of blood lead levels, with the recent reference value of 80 mg/l for men, and the rising trend of blood selenium levels in adults, but not in children.

Chromosomal aberration frequencies determined by conventional methods: Parallel increases over time in the region of a petrochemical industry and throughout the Czech Republic.

The rationale for cytogenetic monitoring to determine if safe maximum allowable concentrations (MAC) of genotoxic chemicals are being maintained in a workplace is that exposure levels that do not increase chromosomal aberration frequencies are without harmful effects. Such monitoring, widely used in occupational health programs in the Czech Republic (CR), includes workers exposed to 1,3-butadiene (BD) or other chemicals. Studies of BD exposed workers in the years 1992, 1993, 1994, 1998, and 2004 compared mean frequencies of cells carrying chromosomal aberrations (frequency of aberrant cells=%AB.

Possible genetic damage in the Czech nuclear power plant workers.

The aim of our study was to identify occupational risk of irradiation exposure in the Czech nuclear power plant workers. We analyzed levels of chromosomal aberrations, a well-known biomarker of early biological effects and a predictor of cancer risk. We applied the conventional method of cytogenetic analysis and fluorescence in situ hybridization (FISH, whole chromosome painting for chromosomes 1 and 4, combined with a pancentromeric probe) to three groups: 123 subjects in the Temelin nuclear power plant (2 years in use), 114 subjects in the Dukovany nuclear power plant (20 years in use), and 53 matched controls from Ceske Budejovice.

Chromosomal aberrations in peripheral lymphocytes of children as biomarkers of environmental exposure and life style.

The original purpose of our study was to determine if the detection of chromosomal aberrations in peripheral lymphocytes of children might be used as a biomarker of environmental pollution and life style. We compared the results of cytogenetic analyses performed in children and adolescents in the periods 1984-1993 and 1994-1999, in a total of 3402 subjects. The frequency of aberrant cells (AB.

Spontaneous level of chromosomal aberrations in peripheral blood lymphocytes of control individuals of the Czech Republic population.

In order to assess the potential of cytogenetic determinations on peripheral blood lymphocytes as a mean of monitoring human population subjects to occupational and environmental exposures to genotoxins, accurate baseline data are required. During the past 20 years many results of the cytogenetic studies on peripheral blood lymphocytes from monitored occupationally exposed and non-exposed groups were obtained. At the time of blood drawing a questionnaire was administered.

Population-based biomonitoring in the Czech Republic--the system and selected results.

In the framework of the system of monitoring the environmental impact on population health, the concentration of lead, cadmium and selenium in blood and cadmium in urine was measured in adults (n = 670), children (n = 599) and umbilical blood (n = 549) using atomic absorption spectrophotometry. Furthermore, cytogenetic analysis of peripheral lymphocytes in all population groups under study was investigated. The median blood Pb level for the overall group of adults (47.

Genotoxicity of industrial effluents, river waters, and their fractions using the Ames test and in vitro cytogenetic assay.

Total and fractionated organic extracts from industrial effluents and Labe river water were tested for mutagenicity using the Ames test with TA98 strain and its YG derivatives (YG1021, YG1024 and YG1041) and cytogenetic analysis with human peripheral lymphocytes in vitro. The bacterial mutagenicity results showed a dose-dependent increase in numbers of TA98 revertants (10(5)) with effluent extracts and lower, but still significant, increase (10(3)) with river water extracts 6 km downstream. The further increase of YG revertants indicates the possible presence of nitroarenes and aromatic amines in the tested samples.

Monitoring of human exposure to occupational genotoxicants.

The human exposure to genotoxic agents can be detected by using genetic monitoring procedures which is mainly concerned with markers of exposure and effect. Cytogenetic analysis of human peripheral lymphocytes and urine mutagenicity are routinely used in Hygiene Service of the Czech Republic. The review demonstrated the activity of National Reference laboratory and other laboratories in Hygiene Service of the Czech Republic in the problem dealing with monitoring of population exposure to genotoxic substances.

Monitoring genotoxic exposure in uranium miners.

Recent data from deep uranium mines in Czechoslovakia indicated that in addition to radon daughter products, miners are also exposed to chemical mutagens. Mycotoxins were identified as a possible source of mutagenicity present in the mines. Various methods of biomonitoring were used to examine three groups of miners from different uranium mines.

Mutagenic activity of paracetamol. A study conducted on volunteers.

The mutagenic activity of paracetamol (PC) was studied on a group of healthy persons (3 men, 8 women) after the simultaneous administration of 3 X 1000 mg of PC and an identical dose of PC + 1000 mg of ascorbic acid within a period of 8 hours. Blood sample tests were made at intervals of 0, 24, 72 and 168 hours. A cytogenetic analysis showed that in 24 hours PC had increased the aberrant cell frequency to 2.

[Mutagenic activity of paracetamol. A study in volunteers].

Mutagenic activity of paracetamol (PC) was studied in a group of healthy persons (3 men, 8 women) after a simultaneous administration of 3 x 1000 mg of PC and of identical dose of PC + 1000 mg of ascorbic acid within an 8 hr. period. Blood sample tests were made at intervals 0, 24, 72 and 168 hrs.

Mutagenicity studies on paracetamol in human volunteers. I. Cytogenetic analysis of peripheral lymphocytes and lipid peroxidation in plasma.

The clastogenic activity of paracetamol (PC) was assayed on a group of 11 healthy volunteers. PC was administered in the form of tablets 3 x 1000 mg in the course of 8 h. Blood samples were taken 0, 24, 72 and 168 h after the first application of the drug.

HLA antigens in three Siberian populations.

The distribution of HLA phenotypes, gene and haplotype frequencies was studied in three Mongoloid populations in Central Asia (Tofs, Tuvinians and Buryats). In comparison with Caucasian populations increased frequency of HLA-A9, BW40 and BW15 and haplotype A9, BW15 as well as low frequency of HLA-A1, B8 and B12 are characteristic of all three populations. Buryats seem to have the relatively highest admixture of Caucasoid genes.