Three rounds of a national external quality assessment reveal a link between disharmonic anti-SARS-CoV-2 antibody quantifications and the infection stage.

OBJECTIVES: The WHO's standardized measuring unit, "binding antibody units per milliliter (BAU/mL)," should allow the harmonization of quantitative results by different commercial Anti-SARS-CoV-2 immunoassays. However, multiple studies demonstrate inter-assay discrepancies. The antigenic changes of the Omicron variant affect the performance of Spike-specific immunoassays. This study evaluated the variation of quantitative Anti-SARS-CoV-2-Spike antibody measurements among 46, 50, and 44 laboratories in three rounds of a national external quality assessment (EQA) prior to and after the emergence of the Omicron variant in a diagnostic near-to-real-life setting. METHODS: We analyzed results reported by the EQA participant laboratories from single and sequential samples from SARS-CoV-2 convalescent, acutely infected, and vaccinated individuals, including samples obtained after primary and breakthrough infections with the Omicron variant. RESULTS: The three immunoassays most commonly used by the participants displayed a low intra-assay and inter-laboratory variation with excellent reproducibility using identical samples sent to the participants in duplicates. In contrast, the inter-assay variation was very high with all samples. Notably, the ratios of BAU/mL levels quantified by different immunoassays were not equal among all samples but differed between vaccination, past, and acute infection, including primary infection with the Omicron variant. The antibody kinetics measured in vaccinated individuals strongly depended on the applied immunoassay. CONCLUSIONS: Measured BAU/mL levels are only inter-changeable among different laboratories when the same assay was used for their assessment. Highly variable ratios of BAU/mL quantifications among different immunoassays and infection stages argue against the usage of universal inter-assay conversion factors.

Results of a SARS-CoV-2 virus genome detection external quality assessment round focusing on sensitivity of assays and pooling of samples.

OBJECTIVES: Results of earlier external quality assessment (EQA) rounds suggested remarkable differences in the sensitivity of SARS-CoV PCR assays. Although the test systems are intended to detect SARS-CoV-2 in individual samples, screening is often applied to sample pools to increase efficiency and decrease costs. However, it is unknown to what extent these tests actually meet the manufacturer's specifications for sensitivity and how they perform when testing sample pools. METHODS: The sensitivity of assays in routine use was evaluated with a panel of positive samples in a round of a SARS-CoV-2 virus genome detection EQA scheme. The panel consisted of samples at or near the lower limit of detection ("weakly positive"). Laboratories that routinely test sample pools were asked to also analyze the pooled EQA samples according to their usual pool size and dilution method. RESULTS: All participants could detect a highly positive patient-derived sample (>106 copies/mL). Most (96%) of the test systems could detect at least 1,000 copies/mL, meeting the minimum acceptable benchmark, and many (94%) detected the vRNA in a sample with lower concentration (500 copies/mL). The false negative ratio increased to 16 and 26% for samples with 100 and 50 copies/mL, respectively. CONCLUSIONS: The performance of most assays met or exceeded their specification on sensitivity. If assays are to be used to analyze sample pools, the sensitivity of the assay and the number of pooled samples must be balanced.

Inadequate design of mutation detection panels prevents interpretation of variants of concern: results of an external quality assessment for SARS-CoV-2 variant detection.

OBJECTIVES: Mutation-specific PCR assays have quickly found their way into laboratory diagnostics due to their capacity to be a fast, easy to implement and high-throughput method for the detection of known SARS-CoV-2 variants of concern (VoCs). However, little is known about the performance of such assays in routine laboratory analysis. METHODS: The results reported in a recent round of an external quality assessment (EQA) scheme for SARS-CoV-2 mutation-specific PCR were retrospectively analyzed. For the determination of individual variant-specific sequences as well as for the interpretation results for certain virus variants, correct, incorrect, and unreported results were evaluated, and their possible causes were investigated. RESULTS: A total of 34 laboratories participated in this study. For five samples containing the VoC Alpha + E484K, Beta, Gamma, Delta, or B.1.1.318 (as a variant of interest), 848 results for SARS-2-CoV mutation detection were reported, 824 (97.2%, range per sample 88-100%) of which were correct. Melting curve assays gave 99% correct results, real-time RT-qPCR 94%, microarray-based assays 100%, and MALDI-TOF MS 96%. A total of 122/167 (73%) reported results for SARS-CoV-2 variant determination were correct. Of the 45 inconclusive or incorrect results, 33 (73%) were due to inadequate selection of targets that did not allow identification of contemporary VoC, 11 (24%) were due to incorrect results, and one (3%) was due to correct results of mutation-specific PCR. CONCLUSIONS: Careful and up-to-date selection of the targets used in mutation-specific PCR is essential for successful detection of current SARS-CoV-2 variants.

The versatility of external quality assessment for the surveillance of laboratory and in vitro diagnostic performance: SARS-CoV-2 viral genome detection in Austria.

OBJECTIVES: External quality assessment (EQA) schemes provide information on individual and general analytical performance of participating laboratories and test systems. The aim of this study was to investigate the use and performance of SARS-CoV-2 virus genome detection systems in Austrian laboratories and their preparedness to face challenges associated with the pandemic. METHODS: Seven samples were selected to evaluate performance and estimate variability of reported results. Notably, a dilution series was included in the panel as a measure of reproducibility and sensitivity. Several performance criteria were evaluated for individual participants as well as in the cohort of all participants. RESULTS: A total of 109 laboratories participated and used 134 platforms, including 67 different combinations of extraction and PCR platforms and corresponding reagents. There were no false positives and 10 (1.2%) false negative results, including nine in the weakly positive sample (Ct ∼35.9, ∼640 copies/mL). Twenty (22%) laboratories reported results of mutation detection. Twenty-five (19%) test systems included amplification of human RNA as evidence of proper sampling. The overall linearity of Ct values from individual test systems for the dilution series was good, but inter-assay variability was high. Both operator-related and systematic failures appear to have caused incorrect results. CONCLUSIONS: Beyond providing certification for participating laboratories, EQA provides the opportunity for participants to evaluate their performance against others so that they may improve operating procedures and test systems. Well-selected EQA samples offer additional inferences to be made about assay sensitivity and reproducibility, which have practical applications.

Evaluation of genotoxic potential of tert-butylquinone and its derivatives in prokaryotic and eukaryotic test models.

Tert-butylquinone (TBQ) and its alkylamino and aralkylamino derivatives are of high interest as a potential antitumor agent. Therefore, it was necessary to investigate if the compounds exert undesirable activities such as interaction with DNA molecule which could result in negative side effects in the case of their use in the diseases treatment. The major aim of this study was to investigate genotoxic potential of TBQ and selected derivatives in an acellular model by using plasmid DNA, in the prokaryotic model by the SOS/umuC assay in Salmonella typhimurium TA1535/pSK1002 and in eukaryotic models by using comet assay in human fetal lung cell line (MRC-5) and human liver cancer cell line (HepG2). Results indicated that in the acellular model TBQ and its derivatives do not interact with plasmid pUC19. In the prokaryotic model, only TBQ exerted weak genotoxic potential and only at highly cytotoxic concentrations. In eukaryotic models, genotoxic potential was detected mainly at the highest concentrations of the tested substances but the effect was lower in both cell lines in comparison with benzo[a]pyrene and etoposide which were used as positive controls. Weak genotoxic potential of tested compounds recommends them as good candidates for further testing in development of new antitumor agents.

Converting to an international unit system improves harmonization of results for SARS-CoV-2 quantification: Results from multiple external quality assessments.

BACKGROUND: The detection of SARS-CoV-2 vRNA in clinical samples has relied almost exclusively on RT-qPCR as the gold standard test. Published results from various external quality assessments ("ring trials") worldwide have shown that there is still a large variability in results reported for the same samples. As reference standards of SARS-CoV-2 RNA are available, we tested whether using standard curves to convert Ct values into copies/mL (cp/mL) improved harmonization. METHODS: Nine laboratories using 23 test systems (15 of which were unique) prepared standard dilution curves to convert Ct values of 13 SARS-CoV-2 positive samples to cp/mL (hereafter IU/mL). The samples were provided in three rounds of a virus genome detection external quality assessment (EQA) scheme. We tested the precision and accuracy of results reported in IU/mL, and attempted to identify the sources of variability. RESULTS: Reporting results as IU/mL improved the precision of the estimated concentrations of all samples compared to reporting Ct values, although some inaccuracy remained. Variance analysis showed that nearly all variability in data was explained by individual test systems within individual laboratories. When controlling for this effect, there was no significant difference between all other factors tested (test systems, EQA rounds, sample material). CONCLUSIONS: Converting results to copies/mL improved precision across laboratory test systems. However, it seems the results are still very specific to test systems within laboratories. Further efforts could be made to improve accuracy and achieve full harmonization across diagnostic laboratories.

Associations between the occupational stress index and hypertension, type 2 diabetes mellitus, and lipid disorders in middle-aged men and women.

INTRODUCTION: Retrospective and prospective studies show that stress at work is linked to an increased risk of hypertension, diabetes mellitus, and coronary heart disease. However, the nature of the contributory job stressors and biological mechanisms need further elucidation. OBJECTIVES: The study is aimed to determine the associations between aspects of the occupational stress index (OSI) and arterial hypertension, diabetes mellitus (DM) type 2, and lipid disorders in working middle-aged men and women. METHODS: The cross-sectional study involved 989 middle-aged men and women in different occupations. The OSI was calculated by using standardized questionnaires. The total participation rate was 93%. Occupational stressors were divided into seven groups: High Demands, Strictness, Underload, Extrinsic Time Pressure, Noxious Exposure, Avoidance, and Conflict/Uncertainty. Serum lipid levels, glucoregulation, blood pressure, and cardiovascular risk factors were measured. RESULTS: For both women and men, the total OSI score associated significantly with DM (women: odds ratio [OR] 2.4, 95% confidence intervals [CI] 1.67-3.45; men: 1.21, 1.15-1.45), any type of dyslipidemia (women: 1.54, 1.17-2.03; men: 1.31, 1.24-1.39), and arterial hypertension (women: 1.15, 1.10-1.21; men: 1.58, 1.49-1.68). The group as a whole showed associations between total OSI and low high-density lipoprotein (HDL) cholesterol, high total cholesterol, and high triglyceride levels. Of the OSI aspects, Underload associated significantly in both men and women with arterial hypertension (women: 3.48, 1.91-6.31; men: 2.71, 1.96-3.75) and dyslipidemia (women: 3.26, 2.13-4.99; men: 2.11, 1.76-2.52). Underload was also associated with several lipid abnormalities in the group as a whole. It associated with DM in women only (4.7, 2.84-7.81). All remaining OSI aspects also associated significantly and positively with DM in women only. Conversely, in male workers, but not female workers, High Demand, Conflict/Uncertainty, and Extrinsic Time Pressure associated significantly with arterial hypertension. Strictness and Conflict/Uncertainty associated positively with dyslipidemia in women only. Noxious Exposures associated positively with DM and arterial hypertension in women only. CONCLUSIONS: The study provides evidence for the association of work stress with metabolic disorders and hypertension. Total OSI associated significantly with DM type 2, arterial hypertension, and dyslipidemia in both genders. Different OSI aspects associated with these health issues in gender- and occupational-specific patterns. Underload, which represents lack of social communication, simple task preparation, and underestimation of working results, associated most strongly of all OSI aspects with disease in both the sexes.

Occupational and non-occupational risk factors correlating with the severity of clinical manifestations of carpal tunnel syndrome and related work disability among workers who work with a computer.

The contribution of certain occupational and personal factors to the development of carpal tunnel syndrome (CTS) is still uncertain. We investigated which specific occupational and non-occupational factors correlate with the level of clinical manifestations and work disability related to CTS. The study included 190 workers who work with a computer and have diagnosed CTS (100 men, 90 women, aged 20-65 years). Subjective experience of CTS-related impairments was assessed with the Symptom Severity Scale (SSS) and the Functional Status Scale (FSS) of the Boston Carpal Tunnel Syndrome Questionnaire (BCTQ). The objective, neural impairments were tested with electrodiagnostics (EDX), whereas CTS-related work disability data were collected from medical records. We found a high inter-correlation between BCTQ, EDX, and work disability data. These also showed high correlations with certain occupational factors (duration of computer-working in months and hours spent daily in computer-working, certain ergonomic, microclimatic, and other occupational conditions) and non-occupational factors (demographic and lifestyle factors: nutritional status, diet, smoking, alcohol consumption, and physical activity). Despite its limitations, our study has identified occupational and non-occupational risk factors that can aggravate CTS and work disability, but which can also be improved with workplace and lifestyle preventive and corrective measures. More research is needed, though, to establish the possible causal relationships and the independent influence of each of those risk factors.

Alteration in Redox Status and Lipoprotein Profile in COVID-19 Patients with Mild, Moderate, and Severe Pneumonia.

Background: Metabolic alterations, particularly disorders of lipoprotein metabolism in COVID-19, may affect the course and outcome of the disease. This study aims at evaluating the lipoprotein profile and redox status in SARS-CoV-2 infected patients with different pneumonia severity and their association with lethal outcomes. Methods: The prospective cohort study was performed on 98 COVID-19 patients with mild, moderate, and severe pneumonia. Lipid and inflammatory parameters, lipoprotein subclasses, and redox status biomarkers were determined at the study entry and after one week. Results: Compared to patients with mild and moderate pneumonia, severely ill patients had higher oxidised low-density lipoprotein (oxLDL) and malondialdehyde levels and lower high-density lipoprotein cholesterol (HDL-C) concentrations and paraoxonase 1 activity. Reduction in the proportion of large HDL 2a subclasses with a concomitant increase in the proportion of smallest HDL 3c and small dense LDL (sdLDL) particles was observed in patients with severe disease during the time. However, these changes were reversed in the mild and moderate groups. The results showed a positive association between changes in oxLDL and total antioxidative status. However, prooxidants and antioxidants in plasma were lower in patients with lethal outcomes. Conclusions: Increased levels of oxLDL and sdLDL particles may contribute to the severity of COVID-19. The role of oxidative stress should be clarified in further studies, mainly its association with lethal outcomes.

The relationship between occupational stress, health status, and temporary and permanent work disability among security guards in Serbia.

Purpose. This study aimed to examine the influence of occupational stress on health status and work disability among security guards in Serbia. Methods. Three hundred and ninty nine male security guards (aged 25-65 years) were examined during regular medical preventive check-ups at the Institute of Occupational Health. Data on their health status and permanent and temporary work disability were obtained, and correlations with the levels of occupational stress (measured by occupational stress index [OSI] questionnaire) were analysed. Results. A high prevalence of health impairments, including diabetes (38.8%), dyslipidaemia (82.7%), hypertension (69.9%) and metabolic syndrome (77.7%), was found. Highly significant correlations were shown between reported levels of total stress at work (total OSI score) and measured values of glucose, lipids, blood pressure, heart rate, Framingham cardiovascular risk scale, occurrence of diabetes and impaired fasting glucose, dyslipidaemia, hypertension, metabolic syndrome, coronary heart disease, cerebrovascular insults, degenerative eye-fundus changes, and temporary and permanent work disability. All of these correlations remained significant even after adjustments for age, body mass index and smoking status. Regression analysis confirmed the independent effect of occupational stress on the analysed parameters. Conclusions. There is a significant independent impact of occupational stress on development of health impairments and work disability among security guards.

RT-PCR based SARS-CoV-2 variant screening assays require careful quality control.

BACKGROUND: Distinctive genotypes of SARS-CoV-2 have emerged that are or may be associated with increased transmission, pathogenicity, and/or antibody escape. In many countries, clinical and diagnostic laboratories are under mandate to identify and report these so-called variants of concern (VOC). OBJECTIVES: We used an external quality assessment scheme to determine the scope, accuracy, and reliability of laboratories using various molecular diagnostic assays to identify current VOC (03 March 2021). STUDY DESIGN: Participant laboratories were sent the same five patient-derived samples and were asked to provide their variant detection methods, variant detection results and interpretation of results. RESULTS: Twenty-five laboratories reported a range of RT-qPCR-based assays to identify specific variations in the SARS-CoV-2 spike protein that are characteristic of three VOC lineages. Laboratories that detected VOC-associated nucleotide mutations at four specific sites had the highest ratio of correct classification. Low template copy number and additional variation in target regions resulted in loss of confidence and accuracy in sample classification. CONCLUSIONS: Melting-curve-based assays to identify genomic variants are less time-consuming and require less bioinformatic analysis compared to partial or whole genome sequencing. However, our results suggest that correct classification of a given genotype/lineage (e.g., a VOC) relies on the ability to detect more than one variant site, adequate template in the sample (i.e., relatively high viral load/copy number) and results may be unclear in certain samples with additional genetic variations. These initial results suggest that some diagnostic laboratories may require additional training to interpret and report complex genetic information about a dynamic emerging virus.

Interstitial Cells of Cajal and Neural Structures in the Human Fetal Appendix.

BACKGROUND/AIMS: The interstitial cells of Cajal (ICC) are located within and around the digestive tract's muscle layers. They function as intestinal muscle pacemakers and aid in the modification of enteric neurotransmission. The appendix's unique position requires an appropriate contraction pattern of its muscular wall to adequately evacuate its contents. We investigated the development and distribution of nervous structures and ICC in the human fetal appendix. METHODS: Specimens were exposed to anti-c-kit (CD117) antibodies to investigate ICC differentiation. Enteric plexuses were examined using anti-neuron-specific enolase, and the differentiation of smooth muscle cells was studied with anti-desmin antibodies. RESULTS: During weeks 13-14, numerous myenteric plexus ganglia form an almost uninterrupted sequence throughout the body and apex of the appendix. Fewer ganglia were present at the submucosal border of the circular muscle layer and within this layer. A large number of ganglia appear within the circular and longitudinal muscle layers in a later fetal period. The first ICC subtypes noted were of the myenteric plexus and the submucous plexus. In the later fetal period, the number of intramuscular ICC markedly rises, and this subtype becomes predominant. CONCLUSIONS: The ICC and nervous structure distribution in the human fetal appendix are significantly different from all other parts of the small and large intestine. The organization of ICC and the enteric nervous system provides the basis for the specific contraction pattern of the muscular wall of the appendix.

Frequent aberrant DNA methylation of ABCB1, FOXC1, PPP2R2B and PTEN in ductal carcinoma in situ and early invasive breast cancer.

INTRODUCTION: Ductal carcinoma in situ (DCIS) is a non-invasive lesion of the breast that is frequently detected by mammography and subsequently removed by surgery. However, it is estimated that about half of the detected lesions would never have progressed into invasive cancer. Identifying DCIS and invasive cancer specific epigenetic lesions and understanding how these epigenetic changes are involved in triggering tumour progression is important for a better understanding of which lesions are at risk of becoming invasive. METHODS: Quantitative DNA methylation analysis of ABCB1, CDKN2A/p16INK4a, ESR1, FOXC1, GSTP1, IGF2, MGMT, MLH1, PPP2R2B, PTEN and RASSF1A was performed by pyrosequencing in a series of 27 pure DCIS, 28 small invasive ductal carcinomas (IDCs), 34 IDCs with a DCIS component and 5 normal breast tissue samples. FOXC1, ABCB1, PPP2R2B and PTEN were analyzed in 23 additional normal breast tissue samples. Real-Time PCR expression analysis was performed for FOXC1. RESULTS: Aberrant DNA methylation was observed in all three diagnosis groups for the following genes: ABCB1, FOXC1, GSTP1, MGMT, MLH1, PPP2R2B, PTEN and RASSF1A. For most of these genes, methylation was already present at the DCIS level with the same frequency as within IDCs. For FOXC1 significant differences in methylation levels were observed between normal breast tissue and invasive tumours (P < 0.001). The average DNA methylation levels were significantly higher in the pure IDCs and IDCs with DCIS compared to pure DCIS (P = 0.007 and P = 0.001, respectively). Real-time PCR analysis of FOXC1 expression from 25 DCIS, 23 IDCs and 28 normal tissue samples showed lower gene expression levels of FOXC1 in both methylated and unmethylated tumours compared to normal tissue (P < 0.001). DNA methylation levels of FOXC1, GSTP1, ABCB1 and RASSF1A were higher in oestrogen receptor (ER) positive vs. ER negative tumours; whereas methylation levels of FOXC1, ABCB1, PPP2R2B and PTEN were lower in tumours with a TP53 mutation. CONCLUSIONS: Quantitative methylation analysis identified ABCB1, FOXC1, PPP2R2B and PTEN as novel genes to be methylated in DCIS. In particular, FOXC1 showed a significant increase in the methylation frequency in invasive tumours. Low FOXC1 gene expression in both methylated and unmethylated DCIS and IDCs indicates that the loss of its expression is an early event during breast cancer progression.

Serum lipids and glucose disturbances at professional drivers exposed to occupational stressors.

The aim of this study is to find association between some groups of occupational stressors and serum lipids and glucose concentrations in professional drivers in road traffic. The study included 417 male professional drivers (162 inter city bus drivers, 36 suburban bus drivers, 33 city bus drivers, 81 truck drivers, 71 official car drivers and 34 professional taxi drivers). Occupational stressors were identified and total occupational stress index score was measured by standardized questionnaire authorized by Karen Belkic. Occupational stressors were divided into seven groups (underload, high demand, strictness, extrinsic time pressure, noxious exposures, avoidance and conflict). Serum glucose and lipids concentrations (total cholesterol, LDL cholesterol, HDL cholesterol and triacylglycerols) were measured in study group of drivers. Maximal total OSI values were achieved in group of professional truck drivers. The highest values of serum glucose, total cholesterol, LDL cholesterol and triacylglycerols and the lowest values of serum HDL cholesterol were found at professional truck drivers. With the increase of occupational stress index, there is an increase of the serum glucose, total cholesterol, LDL cholesterol and triacylglycerols concentration in the exposed group of drivers. Specific analytes thresholds' level of occupational stress index exists.

Evaluation of genotoxic potential in the Velika Morava River Basin in vitro and in situ.

The Velika Morava River is the greatest national Serbian river and the significant tributary of the Danube River. The major problems in the Velika Morava River Basin (VMRB) represent untreated industrial and municipal wastewaters. In this study, the level of genotoxic potential at the sites along the VMRB was evaluated by parallel in vitro and in situ approach. Within in vitro testing, genotoxicity of native water samples collected from the sites in VMRB was evaluated by SOS/umuC test on Salmonella typhimurium TA1535/pSK1002 and by the comet assay on HepG2 cells. DNA damage in situ was assessed in bleak (Alburnus alburnus) erythrocytes by the comet (alkaline and Fpg-modified comet) and micronucleus assays. Additionally, the concentration of heavy metals in fish tissue was measured and this data, compiled with the data of the physico-chemical parameters measured in water, was used as a measure of the pollution pressure at the sites. Results showed that applied in vitro tests with native water samples are less sensitive in comparison with in situ tests and should be taken with precaution when making predictions on the status of the ecosystem. Within applied battery of in situ assays differential sensitivity of assays was observed where alkaline comet assay showed the highest potential in differentiation of the sites based on genotoxic potential. Integrated biomarker response showed that usage of the battery of bioassays provides better insight in a genotoxic effects in animals, and consequently, that the holistic approach is more suitable for this type of study.

The impact of occupational stress factors on temporary work disability related to arterial hypertension and its complications.

AIM: To determine which specific groups of occupational stress factors influence the duration of temporary work disability related to arterial hypertension and joint complications/co-morbidities. METHODOLOGY: Workers (n = 1398; 1009 in the exposed group, 389 in the control group) with arterial hypertension who worked at one workplace for a minimum of 10 years were divided into 10 subgroups, depending on the presence of joint complications/co-morbidities. The intensity of seven groups of occupational stress factors, the total score of Occupational Stress Index (OSI) and the average number of lost working days during 1 year were analysed. RESULTS: The number of lost working days due to arterial hypertension and joint complications/co-morbidities was significantly higher in the exposed group. In all subgroups of the exposed group there was a high correlation between the number of lost working days and the total OSI score. Specific occupational stress factors were associated with specific complications: High Demands with chronic myocardial infarction, Strictness with cerebral haemorrhage, Conflict/Uncertainty with cerebral infarction, Extrinsic Time Pressure with acute myocardial infarction, and Avoidance/Symbolic Aversiveness with non-insulin-dependent diabetes. CONCLUSION: There are specific groups of occupational stress factors which can influence the duration of work disability associated with certain complications and co-morbidities of arterial hypertension.

Evaluation of genotoxic potential throughout the upper and middle stretches of Adige river basin.

In this study a comprehensive genotoxicological survey throughout the upper and middle stretches of Adige river basin is presented. The study was carried out at 7 sites located along the Adige main course and one the most significant tributaries, the Noce creek, both presenting different levels of pollution pressure. To give an insight into the nature of the genotoxic activity we employed the battery of prokaryotic and eukaryotic assays. Mutagenicity in water samples was evaluated by SOS/umuC test in Salmonella typhimurium TA1535/pSK1002. The level of DNA damage as a biomarker of exposure (comet assay) and biomarker of effect (micronucleus assay) and the level of oxidative stress as well (Fpg - modified comet assay) were studied in blood cells of Salmo cenerinus Nardo, 1847 and Salmo marmoratus Cuvier, 1829. Within the applied bioassays, comet assay showed the highest potential for discriminating the sampling sites which are under lesser extent of pressure (sampling sites 1-Barnes at Bresimo and 4-Noce downstream S. Giustina) from the sites under high pressure (sampling sites 5-Noce at Mezzolombardo and 6/7-Adige upstream and downstream municipality of Trento). Significant correlation between the standard and Fpg - modified comet assay indicated that oxidative stress could be a major contributor to observed DNA damage in collected specimens.

[Effects of occupational stress on working ability of patients suffering from arterial hypertension].

INTRODUCTION: The aim of this research was to quantify the presence of occupational stressors and to analyze their effects on temporary and permanent working ability of workers with arterial hypertension. MATERIAL AND METHODS: The research included 817 workers. The study group consisted of 504 workers with arterial hypertension without other diseases or disorders, whereas the control group was composed of 313 healthy workers. RESULTS: The study group showed a significantly higher level of total occupational stress index as well as of the stress index related to high job demands, conflicts at work place, underload and time limit (p<0.001) compared to the control group. A positive and statistically significant correlation between total occupational stress index and systolic and diastolic blood pressure was found in the study group. The total level of occupational stress over 40 led to a significant increase of systolic and diastolic blood pressure in persons with arterial hypertension. The analysis of temporary working inability determined a statistically significantly higher level of lost workdays per a worker in the study group compared to the controls (p<0.001). The average number of lost workdays per a worker in a year in the study group increased statistically significantly along with the occupational stress index values at their work place (p<0.001). In the study group the number of workers eligible for disability retirement over a period of one year was significantly higher compared to the controls. The number of workers eligible for disability retirement in the exposed group increased statistically significantly along with occupational stress index values at their work place. CONCLUSION: The results show that occupational stress is a significant factor in the development of arterial hypertension and reduction of work ability of exposed workers.

Work stress related lipid disorders and arterial hypertension in professional drivers - a cross-sectional study.

BACKGROUND/AIM: Occupational stress is a term used to define ongoing stress that is related to the workplace. The study was conducted to determine association of occupational stress index (OSI) and its aspects with arterial hypertension and lipid disorders using data from a cross-sectional survey of male professional drivers. METHODS: The cross-sectional study was performed in 439 professional drivers divided into groups (city- and intercity bus drivers, truck and taxi drivers). The OSI and OSI aspects (high demands, strictness, underload, extrinsic time pressure, noxious exposure, avoidance and conflict) were calculated using the standardized questionnaire. Determination of serum lipids, blood pressure (BP) and cardiovascular risk factors were done. RESULTS: A significant difference in prevalence of diagnosed hypertension and dyslipidemia was found along with a difference in total OSI and OSI aspects among examined subgroups of drivers. A total OSI was highest in city, high in intercity bus drivers, and the lowest one in truck and taxi drivers (82.79 +/- 3.5, 81.28 +/- 3.7, 73.75 +/- 3.5, 71.61 +/- 4.4, respectively; p < 0.01). Similar pattern showed triglycerides (TG), total cholesterol (TC) and LDL cholesterol and BP, while HDL-cholesterol showed reverse order (p < 0.01). Logistic regression analyses with multiple OSI aspects adjusted for age and years of exposure showed associations of total OSI with arterial hypertension [OR 5.5; 95% CI (2.24-7.95)] and dyslipidemia [OR 1.43 95% CI (1.09-2.80)]. Underload was the most important OSI aspect associated with the arterial hypertension [OR 1.18; 95% CI (1.04-2.58)] and elevated LDL cholesterol [1.26; 95 CI (1.19-2.1)]. A total OSI had a significant association with elevated LDL cholesterol [2.64; 95% CI (1.19-7.7)], triglycerides [OR 3.27; 95% CI (1.20-5.1)] and low HDL cholesterol [OR 3.29; 95% CI (1.8-5.8)] (p < 0.01). CONCLUSION: The study provides the evidence for the significant association of total OSI and underload with lipid disorders and elevated blood pressure in professional drivers, which could be a possible link between job stress and coronary heart disease. Regular periodical examinations and workplace interventions aimed to decrease total OSI and underload are important aspects in primary prevention and additional reduction of cardiovascular risk.