Janka Buchancova

Chromosomal damage among medical staff occupationally exposed to volatile anesthetics, antineoplastic drugs, and formaldehyde.

OBJECTIVES Structural chromosomal aberrations in blood lymphocytes represent a biomarker for cellular damage caused by genotoxic carcinogens and are an indicator of increased cancer risk. We evaluated the association between frequencies of total chromosomal aberrations, chromatid- and chromosome-type aberrations, and occupational exposures to volatile anesthetics, antineoplastic agents, and formaldehyde among 601 medical professionals. METHODS Chromosomal damage among exposed individuals and unexposed controls was determined by conventional cytogenetic analysis. We used binary logistic regression to evaluate the effects of workplace exposures and major confounders on chromosomal damage. RESULTS Significantly higher frequencies of total chromosomal, chromatid-type and chromosome-type aberrations were observed among subjects occupationally exposed to volatile anesthetics, antineoplastic agents, and formaldehyde compared to age- and sex-matched controls (P<0.0001). The risk of an increased frequency of chromosomal aberrations was associated with exposure to anesthetics [odds ratio (OR) 3.9, 95% confidence interval (95% CI) 2.7-5.8], cytostatics (OR 2.7, 95% CI 1.9-3.9), and formaldehyde (OR 1.7, 95% CI 1.1-2.7). No other covariate contributed significantly to the model. Chromatid- and chromosome-type aberrations were associated with exposure to anesthetics and cytostatics without any contribution of other variables. Stratified data analysis showed the risk of increased chromosomal aberrations among non-smoking female nurses and physicians exposed to anesthetics, cytostatics and, partially, formaldehyde. Chromatid and chromosome exchanges were significantly higher in the exposed groups than among controls. CONCLUSION Our findings indicate that the presence of genotoxic compounds in operating rooms, oncological units, and pathological departments results in a significant increase of chromosomal damage (impair of chromosomal integrity) among medical workers employed in these facilities.

Chromosomal aberrations in tire plant workers and interaction with polymorphisms of biotransformation and DNA repair genes

We evaluated chromosomal aberrations in lymphocytes of 177 workers exposed to xenobiotics in a tire plant and in 172 controls, in relation to their genetic background. Nine polymorphisms in genes encoding biotransformation enzymes and nine polymorphisms in genes involved in main DNA repair pathways were investigated for possible modulation of chromosomal damage. Chromosomal aberration frequencies were the highest among exposed smokers and the lowest in non-smoking unexposed individuals (2.5+/-1.8% vs. 1.7+/-1.2%, respectively). The differences between groups (ANOVA) were borderline significant (F=2.6, P=0.055). Chromosomal aberrations were higher in subjects with GSTT1-null (2.4+/-1.7%) than in those with GSTT1-plus genotype (1.8+/-1.4%; F=7.2, P=0.008). Considering individual groups, this association was significant in smoking exposed workers (F=4.4, P=0.040). Individuals with low activity EPHX1 genotype exhibited significantly higher chromosomal aberrations (2.3+/-1.6%) in comparison with those bearing medium (1.7+/-1.2%) and high activity genotype (1.5+/-1.2%; F=4.7, P=0.010). Both chromatid- and chromosome-type aberration frequencies were mainly affected by exposure and smoking status. Binary logistic regression analysis revealed that frequencies of chromatid-type aberrations were modulated by NBS1 Glu185Gln (OR 4.26, 95%CI 1.38-13.14, P=0.012), and to a moderate extent, by XPD Lys751Gln (OR 0.16, 95%CI 0.02-1.25, P=0.081) polymorphisms. Chromosome-type aberrations were lowest in individuals bearing the EPHX1 genotype conferring the high activity (OR 0.38, 95%CI 0.15-0.98, P=0.045). Present results show that exposed individuals in the tire production, who smoke, exhibit higher chromosomal aberrations frequencies, and the extent of chromosomal damage may additionally be modified by relevant polymorphisms.

Metabolic gene variants associated with chromosomal aberrations in healthy humans.

Nonspecific chromosomal aberrations (CAs) are found in about 1% of lymphocytes drawn from healthy individuals. They include chromosome‐type aberrations (CSAs), which are increased in exposure to ionizing radiation, and chromatid‐type aberrations (CTAs) which in experimental systems are formed by DNA binding carcinogens and mutagens. The frequency of CAs is associated with the risk of cancer, but the causes of CAs in general population are unknown. Here, we want to test whether variants in metabolic genes associate with CAs in healthy volunteers. Cases were considered those whose total CA (CAtot) frequency was >2% and for CSA and CTA the limit was >1%. Controls had lower frequencies of CAs. Functional polymorphisms in seven genes were selected for analysis: cytochrome P450 1B1 (CYP1B1), epoxide hydrolase 1 (EPHX1), NAD(P)H:quinone oxidoreductase 1 (NQO1), each coding for phase 1 enzymes, and glutathione S‐transferase P1 (GSTP1), glutathione S‐transferases M1 (GSTM1) and T1 (GSTT1), coding for enzymes which conjugate reactive metabolites, that is, phase 2 enzymes. The number of volunteers genotyped for each gene varied from 550 to 1,500. Only EPHX1 was individually associated with CAtot; high activity genotypes decreased CAtot. A total of six significant (P < 0.01) pair‐wise interactions were observed, most including a GST variant as one of the pair. In all genotype combinations with significant odds ratios for CAs a GST variant was involved. The present data provide evidence that variants in genes coding for metabolic enzymes, which individually have small effects, interact and are associated with CA frequencies in peripheral lymphocytes of healthy volunteers.

Cyclin D1 splice site variant triggers chromosomal aberrations in healthy humans.

Chromosomal aberrations (CAs) were suggested to be the cause of cancer by Boveri already a 100 years ago, but the detection of the Philadelphia chromosome about 50 years later provided the first direct evidence on the relationship (reviewed by Mitelman). CAs include recurrent aberrations, including specific translocations, deletions and amplifications of chromosomal regions or whole chromosomes. The detection of recurrent CAs was greatly facilitated when fluorescence in situ hybridization techniques were developed for interphase chromosomes. Non-specific CAs include missing, fragmented or fused chromosomal segments, divided into chromosome-type aberrations (CSAs) and chromatidtype aberrations (CTAs). These have been conventionally analyzed by microscopic scoring of metaphase nuclei from cultured lymphocytes. Modern sequencing techniques have revealed numerous gene fusions and rearrangements, in the extreme, chromothripsis, a catastrophic parsing of illegitimate chromosomal segments together. Non-specific CAs may arise as a result of direct DNA damage by, for example, ionizing radiation or replication on a damaged DNA template; the former lesions would be detected as CSAs, whereas the latter may be CSAs or CTAs. Non-specific CAs remain in lymphocytes for their lifetime. They have been used in monitoring of radiation exposure and exposure to genotoxic compounds and, together with sister chromatid exchanges and micronuclei, CAs have offered the only available method for human biomonitoring for genotoxic exposures. There are convincing data on the association of CA frequency with subsequent risk of many cancers. Furthermore, patients with many types of cancer show increased frequencies of CAs at diagnosis. CAs were assumed to be somatic events but our recent study on multiple myeloma showed that the recurrent t(11;14) (q13;q32) translocation was strongly associated with the cyclin D1 (CCND1) G870A genotype at a splice site. However, no effect was found for any other translocations or other CAs in myeloma. Here, we wanted to test the possible dependence of non-specific CAs on the CCND1 genotype by assaying for the G870A genotype in a large cohort of persons for whom CAs were measured. This polymorphism has been implicated as a risk factor for a number of cancers. The subjects (N1⁄4 731) were identified from occupational settings, including persons with defined exposures (553), and hospital staff without exposures (178) from Slovakia. Occupational exposures included small organic compounds (330), cytostatics (81), anesthetics (74) and metals (68). The median age was 40 years (range 19 to 71), whereas the mean was 40.6 years (s.d. 10.3); characteristics of the population are shown in Table 1. The sampling of peripheral blood was carried out according to the Helsinki Declaration and the study design was approved by the local Ethical Committee of the Jessenius Medical Faculty. The participants provided an informed consent. Cytogenetic analysis was performed on cultured lymphocytes, as previously described, by microscopically analyzing (two microscopists) in a double-blind fashion coded slides of 100 mitoses per person for the frequency of total CAs, CTAs and CSAs. Inter-arm and intra-arm interchanges of CTAs and CSAs (including dicentrics and centric rings) were also scored. In statistical analysis, non-parametric Mann–Whitney U-test was used for testing of differences between the groups. The CAs were categorized into a high-frequency group (42%) and low-frequency group (p2%); this arbitrary cutoff point was based on our previous experience. For CTA and CSA, the cutoff was 1%. Odds ratios (ORs) from multivariable linear regression analysis were employed to consider simultaneous effects of particular occupational exposures, age, gender and smoking habits on the frequencies of CAs, CTAs and CSAs. Genotyping of G870A (rs603965, also known as rs9344) was carried out by the PCR-restriction-fragment length polymorphism method (primer F 50-GTGAAGTTCATTTCCAATCCGC-30, primer R 50-GGGACATCACCCTCACTTAC-30). The amplified fragment was digested with the MspI restriction endonuclease and the digested PCR products were resolved on 3% agarose gels containing ethidium bromide for visualization under UV light. The quality control was performed by random re-genotyping of about 10% of sample. Occupational exposure information was lacking for six individuals. Genotyping of one idividual was not successful, thus 730 persons were successfully genotyped. The results for total CAs showed significant effects of occupational exposure (OR 1.68) and CCND1 AA genotype (OR 1.85, Table 1). In the separate analysis of CTAs and CSAs, the only significant effect of OR 1.99 (P1⁄4 0.003) was on CSAs (Table 2). Our recent study on multiple myeloma showed that the t(11;14) translocation was associated with the CCND1 GG genotype with an OR 1.95 (P1⁄4 2.07 10 ) (Weinhold et al.). The present results showed that AA genotype was associated with overall lymphocyte CAs and, specifically, CSAs in healthy individuals. The opposite genotype effects are likely to be explained by the cell type in question. In the earlier study, we found no genotype effect in mantle cell lymphoma, for which the t(11;14) translocation is a hallmark, most likely because in mantle cell lymphoma the translocations are formed during VDJ recombination when antigen receptor genes are rearranged, earlier than in multiple myeloma. Myeloma is thought to arise from post-germinal center memory B-cells in which immunoglobulin H (IgH) translocations take place during germinal center maturation when somatic hypermutation and class switch recombination take place. Both VDJ and class switch recombination involve complex doublestranded DNA repair events. VDJ recombination is initiated by recombination-activating genes, whereas the germinal center events are catalyzed by activation-induced cytidine deaminase, followed by classical non-homologous DNA end-joining and alternative end-joining repair activities. It is thus likely that the

Comparison of chromosomal aberrations frequency and polymorphism of GSTs genes in workers occupationally exposed to cytostatics or anaesthetics

Comparison of chromosomal aberrations frequency and polymorphism of GSTs genes in workers occupationally exposed to cytostatics or anaesthetics Authors compared the incidence of chromosomal aberrations (CAs) of workers occupationally exposed to cytostatics (group EXP1) or anaesthetics (group EXP2) in relationship to polymorphism of GSTM1, GSTP1 and GSTT1 genes. The cytogenetic analysis for chromosomal aberrations frequency and for polymorphisms of genes the PCR and PCR-RFLP method were used. Statistically higher frequency of total CAs was detected in both exposed groups: group EXP1 1.90±1.34%; Mann-Whitney U-test, p=0.001; group EXP2 2.53±1.46%, p=0.0008) as compared to control (1.26±0.93%). In group EXP2 was detected statistically higher frequency of aberrations CSA-type as compared to CTA-type. In xenobiotic metabolizing genes for GST higher frequency of total CAs and constituent types chromatid-type aberrations (CTAs) and chromosome-type aberrations (CSAs) of genes GSTM1 and GSTT1 with null genotype was detected. Statistically significant difference was detected only in CSA-type of aberrations in GSTT1 gene. In gene GSTP1 was not detected any difference in frequency of aberrations in presence of the variant allele. Presented results point out importance of individual susceptibility in evaluation of genotoxic agents of anaesthetics or cytostatics.

Genetic variation in the major mitotic checkpoint genes associated with chromosomal aberrations in healthy humans

Non-specific chromosomal aberrations (CAs) are microscopically detected in about 1% of lymphocytes drawn from healthy persons. Causes of CAs in general population are not known but they may be related to risk of cancer. In view of the importance of the mitotic checkpoint machinery on maintaining chromosomal integrity we selected 9 variants in main checkpoint related genes (BUB1B, BUB3, MAD2L1, CENPF, ESPL1/separase, NEK2, PTTG1/securin, ZWILCH and ZWINT) for a genotyping study on samples from healthy individuals (N = 330 to 729) whose lymphocytes had an increased number of CAs compared to persons with a low number of CAs. Genetic variation in individual genes played a minor importance, consistent with the high conservation and selection pressure of the checkpoint system. However, gene pairs were significantly associated with CAs: PTTG1-ZWILCH and PTTG1-ZWINT. MAD2L1 and PTTG1 were the most common partners in any of the two-way interactions. The results suggest that interactions at the level of cohesin (PTTG1) and kinetochore function (ZWINT, ZWILCH and MAD2L1) contribute to the frequency of CAs, suggesting that gene variants at different checkpoint functions appeared to be required for the formation of CAs.

Biomonitoring Study – Toxic Elements in Human Blood

The content of toxic heavy metals (As, Cd, Cr, Hg, and Pb) in blood depends on locality, industry and social status of habitants. We studied this determination in detail in 1994.The blood of the young healthy blood donors without any metal exposure was analyzed by the atomic absorption spectrophotometry. The results were used as the reference values of the average non-exposed population. These results did not differ from those gained in other European countries. There is no regular human biomonitoring in Slovakia but there are monitors practiced in neighbouring countries like Czech Republic or Germany. We could suppose the level of exposure in our region from these results and from literature. After 20 years the industry changed and the new technologies bring better quality of environment. It is not very appropriate to compare the results of samples which were analyzed in this time with old table values. But until this study we did not have newer data. We aimed to prepare the new bio-monitoring procedures containing recent data obtained by an inductively coupled plasma-mass spectrometry as new reference values for measurements evaluation.

Analysis of the Incidence of Tick-Borne Encephalitis as an Occupational Disease and of the Costs of the Diagnosis and Treatment of Acute Tick-Borne Encephalitis in the Slovak Republic from 1989 to 2009

Tick-borne encephalitis is a viral disease of the central nervous system that is caused by flaviviruses. The disease can be mild; however, in 35 to 58% of cases, the course of the disease includes long-lasting neurological problems, and the disease can be lethal in 1 to 5% of cases (WHO, 2011). The first symptoms appear about 7 days (incubation period 2 to 28 days) after an infected tick latches on to its host and may present as a flu-like illness. In some people, the second phase of the disease begins after 2 to 4 weeks and is characterised by violent headache, disorientation and high fever; eventually, the patient may lose consciousness, and in many cases, this stage is followed by a long convalescence. Ixodes ricinus, the three-host tick species is parasitic on various stages of development in different hosts, is a disease vector. The larvae is parasitic on small mammals, lizards and birds searching for food on the ground; the nymph is parasitic on larger mammals (hedgehog, squirrel), birds and occasionally on rodents and the imago is parasitic on large mammals (rabbit, fox, deer, wild boar, goat, sheep, cattle, etc.). Imago’s activity in nature is highest from March to October, usually with two peaks: the first peak occurs in June and July, and the second peak occurs in September and October (Grešíková, 1999). The virus is found in the saliva of the tick in all developmental stages but does not harm its host. Humans are infected when they are bitten by an infected female tick. Humans are also infected in alimentary ways, such as by goat, cow or sheep milk and cheese that are insufficiently thermally modified, but this happens less often (WHO, 2009). During the last decade, a shift of infected ticks to the northern regions of Europe and to higher altitudes has been observed. As a result, an increase in the incidence of tick-borne encephalitis has occurred in new locations in Europe and in the Slovak Republic. In the Slovak Republic, the employer is responsible for the damage that is caused to the professional staff by acute occupational poisoning, acute occupational infectious disease and

Assessment of Development and Role of One Day Surgery in Slovak Healthcare System

Assessment of Development and Role of One Day Surgery in Slovak Healthcare System The aim of this article is to describe the development of one day surgery (ODS) and assess its role within the Slovak healthcare system. ODS is a surgical healthcare system based on single treatment of a patient or single diagnostic procedure when performing this healthcare intervention enables dismission of patient in stabilized state in 24 hours. During 1997-1999 the first healthcare facilities of ODS were established in the Slovak Republic. Since then the number of ODS centers has grown to 54. Currently, some 8% of all operations in Slovakia, mainly surgical and ophtalmological, are done via ODS. The authors suggest that, if possible, ODS is an economic option regardless of medical specialty. They expect an increase of facilities performing ODS within existing health structures, establishment of new facilities for ODS and a overall increase in number of ODS interventions in Slovakia in near future. As a conclusion, the authors highlight a possibility of pregradual experience of medical students with ODS and its benefit in dissemination of understanding and positive attitude towards the ODS methods.