DNA methylation in ELOVL2 and C1orf132 correctly predicted chronological age of individuals from three disease groups.

Improving accuracy of the available predictive DNA methods is important for their wider use in routine forensic work. Information on age in the process of identification of an unknown individual may provide important hints that can speed up the process of investigation. DNA methylation markers have been demonstrated to provide accurate age estimation in forensics, but there is growing evidence that DNA methylation can be modified by various factors including diseases. We analyzed DNA methylation profile in five markers from five different genes (ELOVL2, C1orf132, KLF14, FHL2, and TRIM59) used for forensic age prediction in three groups of individuals with diagnosed medical conditions. The obtained results showed that the selected age-related CpG sites have unchanged age prediction capacity in the group of late onset Alzheimer's disease patients. Aberrant hypermethylation and decreased prediction accuracy were found for TRIM59 and KLF14 markers in the group of early onset Alzheimer's disease suggesting accelerated aging of patients. In the Graves' disease patients, altered DNA methylation profile and modified age prediction accuracy were noted for TRIM59 and FHL2 with aberrant hypermethylation observed for the former and aberrant hypomethylation for the latter. Our work emphasizes high utility of the ELOVL2 and C1orf132 markers for prediction of chronological age in forensics by showing unchanged prediction accuracy in individuals affected by three diseases. The study also demonstrates that artificial neural networks could be a convenient alternative for the forensic predictive DNA analyses.

Genetic variants associated with physical and mental characteristics of the elite athletes in the Polish population.

The aim of the study was to assess whether selected genetic variants are associated with elite athlete performance in a group of 413 elite athletes and 451 sedentary controls. Polymorphisms in ACE, ACTN3, AGT, NRF-2, PGC1A, PPARG, and TFAM implicated in physical performance traits were analyzed. Additionally, polymorphisms in CHRNB3 and FAAH coding for proteins modulating activity of brain's emotion centers were included. The results of univariate analyses indicated that the elite athletic performance is associated with four polymorphisms: ACE (rs4341, P = 0.0095), NRF-2 (rs12594956, P = 0.011), TFAM (rs2306604, P = 0.049), and FAAH (rs324420, P = 0.0041). The multivariate analysis adjusted for age and gender confirmed this association. The higher number of ACE D alleles (P = 0.0021) and the presence of NRF-2 rs12594956 A allele (P = 0.0067) are positive predictors, whereas TFAM rs2306604 GG genotype (P = 0.031) and FAAH rs324420 AA genotype (P = 0.0084) negatively affect the elite athletic performance. The CHRNB3 variant (rs4950, G allele) is significantly more frequent in the endurance athletes compared with the power ones (P = 0.025). Multivariate analysis demonstrated that the presence of rs4950 G allele contributes to endurance performance (P = 0.0047). Our results suggest that genetic inheritance of psychological traits should be taken into consideration while trying to decipher a genetic profile of top athletic performance.

Prolactin serum levels and breast cancer: relationships with risk factors and tumour characteristics among pre- and postmenopausal women in a population-based case-control study from Poland.

BACKGROUND: Previous prospective studies have found an association between prolactin (PRL) levels and increased risk of breast cancer. Using data from a population-based breast cancer case-control study conducted in two cities in Poland (2000-2003), we examined the association of PRL levels with breast cancer risk factors among controls and with tumour characteristics among the cases. METHODS: We analysed PRL serum levels among 773 controls without breast cancer matched on age and residence to 776 invasive breast cancer cases with available pretreatment serum. Tumours were centrally reviewed and prepared as tissue microarrays for immunohistochemical analysis. Breast cancer risk factors, assessed by interview, were related to serum PRL levels among controls using analysis of variance. Mean serum PRL levels by tumour characteristics are reported. These associations also were evaluated using polytomous logistic regression. RESULTS: Prolactin levels were associated with nulliparity in premenopausal (P=0.05) but not in postmenopausal women. Associations in postmenopausal women included an inverse association with increasing body mass index (P=0.0008) and direct association with use of recent/current hormone therapy (P=0.0006). In case-only analyses, higher PRL levels were more strongly associated with lobular compared with ductal carcinoma among postmenopausal women (P=0.02). Levels were not different by tumour size, grade, node involvement or oestrogen receptor, progesterone receptor, or human epidermal growth factor receptor 2 status. CONCLUSIONS: Our analysis demonstrates that PRL levels are higher among premenopausal nulliparous as compared with parous women. Among postmenopausal women, levels were higher among hormone users and lower among obese women. These results may have value in understanding the mechanisms underlying several breast cancer risk factor associations.

Elaboration of a quantitative job-exposure matrix for historical exposure to airborne exposures in the Polish rubber industry.

BACKGROUND: A job-exposure matrix (JEM) for inhalable aerosols, aromatic amines, and cyclohexane soluble matter (CSM) was elaborated based on measurements collected routinely between 1981 and 1996. METHODS: The data were grouped based on similarities in exposure levels and time trends in different departments, and were analyzed using smoothing splines and mixed effects models. RESULTS: Although higher than in western European countries, inhalable aerosol exposure decreased after changes in production volume and implementation of exposure reduction measures in mid-1980s. Aromatic amines concentrations first increased following the factory's production volume, but subsequently decreased in more recent years. CSM concentrations were uniformly distributed between departments. CONCLUSIONS: This JEM provides an overview of historical exposure levels in a large Polish rubber factory and will enable estimation of lifetime exposure for individual workers in a Polish rubber workers cohort and further investigation of the associations between specific exposures and cancer risk.

Skewed X chromosome inactivation and early-onset breast cancer.

BACKGROUND: Skewed X chromosome inactivation may be more common in women with epithelial ovarian cancer and early-onset breast cancer. We tested this hypothesis in a group of 235 breast cancer patients and 253 controls (mean age 45.8 years) from a larger population based case control study. METHODS: We measured X chromosome inactivation with the AR gene assay in lymphocyte DNA digested with the methylation specific enzyme HpaII. We judged skewness using an adjusted measure (relative to the undigested sample) with a cut point of 75%, and an unadjusted measure where skewed was defined as > 90% of the signal from one allele in the HpaII digested sample. RESULTS: There were no significant differences in any of the skewing measures between cases and controls. Using the adjusted skewing measure among pre-menopausal subjects under the age of 50, 14% of cases versus 11% of controls were skewed, OR = 1.2, 95% CI 0.6 to 2.3; using the unadjusted measure, OR = 0.9, 95% CI 0.4 to 2.0. CONCLUSIONS: While we cannot rule out a subtle difference of approximately twofold or less, we have failed to find a significant difference in the prevalence of skewed X chromosome inactivation in younger women with breast cancer compared to controls.

Hyperhomocysteinemia and methylenetetrahydrofolate reductase polymorphism in patients with Parkinson's disease.

Elevated levels of homocysteine have been observed in Parkinson's disease (PD) patients treated with levodopa. However, it is not studied if duration of PD or PD per se is associated with hyperhomocysteinemia. In the present study, the levels of homocysteine in 99 levodopa-treated PD patients, 15 untreated PD patients and 100 controls were examined. We focused on the influence of levodopa dose, duration of therapy and disease as well as genetic (C677T methylenetetrahydrofolate reductase (MTHFR) polymorphism) and environmental factors. We found that levodopa-treated PD patients had elevated homocysteine plasma levels as compared to controls (p < 0.05), but the levels did not depend on levodopa doses. Another factor influencing homocysteine level was the duration of PD (p < 0.001). The frequency of allele C677T of MTHFR gene did not differ between PD and controls. In conclusion, hyperhomocysteinemia is associated with the duration of PD and levodopa treatment and possibly also with PD per se.

A mortality study of workers with reported chronic occupational carbon disulfide poisoning.

A mortality cohort study was carried out on 2,291 workers, including 169 women, with chronic occupational CS2 poisoning diagnosed during the years 1970-90. Information on vital status was available for 98.2% as of December 31, 1992. Mortality assessment was based on the standardized mortality ratio using the person-years method. The general population of Poland was the reference population. The number of subjects who died during the period of observation accounted for 658 men and 21 women. The analysis of mortality in male subjects showed statistically significant excess of deaths from the circulatory system diseases (SMR = 139), in this from ischaemic heart disease (SMR = 137), cerebrovascular disease (SMR = 188) and colon cancer (SMR = 233). Over a two-fold increased risk of death from diseases of the nervous system and sense organs, although statistically insignificant, was also observed. Among women a statistically significant risk of death from atherosclerosis was noted (SMR = 286). An elevated risk of death from the circulatory system diseases and from ischaemic disease (IHD) agrees with the results of some other cohort studies carried out in the viscose rayon workers. The increased mortality from malignant neoplasms is an unusual finding in cohorts of workers exposed to CS2. Our own data reported here showed a significantly increased mortality from colon cancer (9 cases). All these cases were noted in workers of the two oldest rayon plants and they require a detailed analysis. Further survey is also needed to elucidate the excess of deaths from the nervous system and sense organs diseases.

[Risk of neoplastic disease in workers from petroleum refineries and in persons employed in fuel distribution]. / Ryzyko choroby nowotworowej wsród pracowników rafinerii ropy naftowej oraz wsród osób zatrudnionych przy dystrybucji paliw.

The author reviews in her paper results of 35 epidemiological surveys, including cohort studies, analysis of mortality and case-control studies. All of them focussed on the assessment of risk of neoplastic disease among workers of petroleum refineries and among persons engaged in the fuel distribution. The results yielded by the afore-said surveys, indicate a lower general mortality and mortality from all malignant neoplasms in the populations under study but a higher risk for the occurrence or death from malignant neoplasm of lymphatic and haematopoietic tissue as well as from malignant neoplasm of skin in the refinery workers. Data on risk of death from malignant neoplasm of digestive organs, kidneys, bones, prostate, brain and the central nervous system among the refinery workers and those on risk of death from malignant neoplasm of lymphatic and haematopoietic tissue, kidneys, stomach and lung in persons engaged in the fuel distribution are very often contradictory. It is most probable that confounding factors are responsible for these contradictions.

[Epidemiologic evaluation of health effects of occupational and non-occupational exposure to carbon disulfide]. / Epidemiologiczna ocena skutków zdrowotnych ekspozycji zawodowej i pozazawodowej na dwusiarczek wegla (CS2).

The review of published results of epidemiologic studies indicates that chronic exposure to carbon disulfide may cause functional and organic disorders of the nervous, circulatory, alimentary and endocrine systems as well as disorders of sight and hearing organs. The epidemiologic studies have been mainly carried out in populations occupationally exposed to carbon disulfide. The majority of data apply to pathologies caused by CS2 in concentrations exceeding MAC values. Some of the studies indicate that the frequency of disorders in lipid metabolism, circulatory and nervous systems as well as in the sight organ is significantly higher in workers exposed to lower concentrations of CS2 but for longer period of time. The studies of mortality show that an increased risk of death from ischaemic heart disease is a late effect of the chronic exposure to CS2. The question of teratogenic and carcinogenic effects of CS2 as well as the problem of health effects of exposure to CS2 of populations living in the vicinity of chemical fibre plants which emit CS2 into the atmosphere still remain without any clear answer.

[Occupational risk factors for breast cancer in the epidemiological studies]. / Zawodowe czynniki ryzyka raka piersi w badaniach epidemiologicznych.

The paper reviews data on the occupational risk factors, which role in the etiology of breast cancer in women has been analyzed and estimated in the epidemiological studies. The results of the studies are presented and discussed. An increased incidence or risk of death from breast cancer was observed in some studies among teachers, nurses and physicians, managerial occupations, beauticians and hairdressers, chemists, telephone and telegraph operators, workers of the pharmaceutical and chemical industry. Some epidemiological studies indicate that breast cancer incidence might be related to occupational exposure to electromagnetic fields, ionizing radiation, low physical activity, organic solvents, selected pesticides. However, owing to inconsistency of the study results and methodological weaknesses (imprecise classification of exposure, low response rate, uncontrolled confounding) no definite conclusion can be drawn.

Two polymorphisms of presenilin-2 gene (PSEN2) 5' regulatory region are not associated with Alzheimer's disease (AD) in the Polish population.

Presenilin 2 gene (PSEN2) is one of the causative genes for familial Alzheimer's disease. A delA polymorphism located in PSEN2 promoter was proposed to be a risk factor for early-onset AD. We examined association between AD and PSEN2 polymorphisms located in two 5'UTR regions in group of 217 late-onset AD patients, 109 mild cognitive impairment patients, and 225 non-demented control subjects. No significant differences for genotype and allele distributions of a delA and a novel insAC polymorphisms in the studied groups as compared to controls were observed. Univariate and multivariate risk estimation shows that neither delA, insAC alleles nor the genotypes are risk factors for AD. No significant interaction between the APOE4 and PSEN2 polymorphisms was found. A bioinformatic analysis showed that delA polymorphism influences binding sites of transcription factors involved in the cellular processes related to AD. The rare variants identified in exon 3 of the PSEN2 could have a potential influence on PSEN2 transcript splicing.

Occupational exposure to NDMA and NMor in the European rubber industry.

Many nitrosamines are suspected of being human carcinogens, with the highest concentrations in the environment being measured in the rubber industry. Time trends of personal exposure to N-nitrosodimethylamine (NDMA) and to N-nitrosomorpholine (NMor) during the past two decades in the German rubber industry were analysed and compared with cross-sectional studies in the same period in the Netherlands, Poland, the UK and Sweden. In the majority of the surveyed departments exposures reduced over time, but considerable heterogeneity was present between departments and sectors. Significant reductions were primarily found in curing and post-treating departments and ranged from -3% year(-1) to -19% year(-1). In contrast, NDMA levels increased (+13% year(-1)) in maintenance and engineering in the tyres industry. Average NDMA-levels in general rubber goods (GRG) and NMor-levels in tyre production in Germany did not decrease significantly in the past two decades, whereas NDMA-levels in tyre production (-10% year(-1)) and NMor-levels in GRG (-7% year(-1)) declined significantly after the introduction of an exposure limit for total nitrosamines in Germany in 1988. Confidence intervals of average exposures in other studied countries largely overlap trends observed in Germany. Exposure to N-nitrosamines decreased on average two-to-five fold in the German rubber industry with comparable concentration levels in other European countries. Although average levels are well below the current limits exposure has not been eliminated, and incidental high exposures do still occur.

The rate of conversion of mild cognitive impairment to dementia: predictive role of depression.

BACKGROUND: Mild cognitive impairment (MCI) is a condition referring to the persons with cognitive deficits measurable in some form or another, but not meeting criteria for dementia, and who have an increased risk of becoming demented. OBJECTIVE: To establish the rate of progression to dementia in MCI, to investigate the risk of conversion for amnestic vs multiple-domains subtypes, and to identify the predictors of progression. METHODS: MCI (n = 105) individuals enrolled in a longitudinal study received annual clinical and psychometric examinations for up to a mean of 3 years. The diagnosis of MCI according to Mayo Clinic Petersen's Criteria was conducted by a panel of specialists. RESULTS: After 3 years of follow-up, 23 of 105 subjects with MCI were diagnosed with dementia. 40 showed cognitive decline not dementia, 34 were stable and showed no cognitive decline or improvement, while eight showed cognitive improvement. CONCLUSIONS: We conclude that conversion rate from MCI to DSM-IIIR dementia was 21.9% over a period of 3 years. The occurrence of depressive symptoms may constitute a predictor for those who are more likely to progress to dementia. The risk of conversion to dementia was higher among the subjects with an evidence of impairment extending beyond memory than with those who suffered only from memory deficits, and the subjects who converted to dementia in this subtype had significantly higher baseline plasma total homocysteine levels than non-converters.

Neurocognition of centenarians: neuropsychological study of élite centenarians.

OBJECTIVE: The aim of this study was to evaluate the cognitive state of highly selected Polish centenarians and analyze the mechanisms of their functioning. METHODS: The selected centenarian group (10 persons) and a reference group (20 persons) who started aging (65 years) were examined with a sensitive set of neuropsychological tests and tasks in clinical-experimental assessment. RESULTS: As expected, the centenarians' cognitive functions were different from those of the subjects who started aging, however, not in all aspects. For instance, the former scored significantly lower in the area of linguistic functions but the ability to plan and controlled perform complex visuospatial task with use of simultaneous and sequential strategies was preserved despite unfavorable symptoms of natural aging such as permanence attention as well as prolonged action time. CONCLUSIONS: The results suggest that the studied centenarians show a dominant right-hemispheric pattern functioning not only in relation to perception, but also to planning and executing complex activities. The study and description of preserved neurocognition of centenarians was possible due to introducing a special procedure sensitive to the preserved functions.

Reproductive risk factors for endometrial cancer among Polish women.

We conducted a population-based case-control study of reproductive factors in Warsaw and Lódz, Poland, in 551 incident endometrial cancer cases and 1925 controls. The reproductive variable most strongly related to risk was multiparity, with subjects with three or more births having a 70% lower risk than the nulliparous women. The reduced risk was particularly strong below 55 years of age. Subjects with older ages at a first birth were also at reduced risk even after adjustment for number of births. Ages at last birth or intervals since last birth were not strongly related to risk. Spontaneous abortions were unrelated to risk, but induced abortions were associated with slight risk increases (odds ratios=1.28, 95% confidence intervals 0.8-2.1 for 3+ vs no abortions). The absence of effects on risk of later ages at, or short intervals since, a last birth fails to support the view that endometrial cancer is influenced by mechanical clearance of initiated cells. Alternative explanations for reproductive effects should be sought, including alterations in endogenous hormones.

Genetic variation in five genes important in telomere biology and risk for breast cancer.

Telomeres, consisting of TTAGGG nucleotide repeats and a protein complex at chromosome ends, are critical for maintaining chromosomal stability. Genomic instability, following telomere crisis, may contribute to breast cancer pathogenesis. Many genes critical in telomere biology have limited nucleotide diversity, thus, single nucleotide polymorphisms (SNPs) in this pathway could contribute to breast cancer risk. In a population-based study of 1995 breast cancer cases and 2296 controls from Poland, 24 SNPs representing common variation in POT1, TEP1, TERF1, TERF2 and TERT were genotyped. We did not identify any significant associations between individual SNPs or haplotypes and breast cancer risk; however, data suggested that three correlated SNPs in TERT (-1381C>T, -244C>T, and Ex2-659G>A) may be associated with reduced risk of breast cancer among individuals with a family history of breast cancer (odds ratios 0.73, 0.66, and 0.57, 95% confidence intervals 0.53-1.00, 0.46-0.95 and 0.39-0.84, respectively). In conclusion, our data do not support substantial overall associations between SNPs in telomere pathway genes and breast cancer risk. Intriguing associations with variants in TERT among women with a family history of breast cancer warrant follow-up in independent studies.

Established breast cancer risk factors by clinically important tumour characteristics.

Breast cancer is a morphologically and clinically heterogeneous disease; however, it is less clear how risk factors relate to tumour features. We evaluated risk factors by tumour characteristics (histopathologic type, grade, size, and nodal status) in a population-based case-control of 2386 breast cancers and 2502 controls in Poland. Use of a novel extension of the polytomous logistic regression permitted simultaneous modelling of multiple tumour characteristics. Late age at first full-term birth was associated with increased risk of large (> 2 cm) tumours (odds ratios (95% confidence intervals) 1.19 (1.07-1.33) for a 5-year increase in age), but not smaller tumours (P for heterogeneity adjusting for other tumour features (Phet) = 0.007). On the other hand, multiparity was associated with reduced risk for small tumours (0.76 (0.68-0.86) per additional birth; Phet = 0.004). Consideration of all tumour characteristics simultaneously revealed that current or recent use of combined hormone replacement therapy was associated with risk of small (2.29 (1.66-3.15)) and grade 1 (3.36 (2.22-5.08)) tumours (Phet = 0.05 for size and 0.0008 for grade 1 vs 3), rather than specific histopathologic types (Phet = 0.63 for ductal vs lobular). Finally, elevated body mass index was associated with larger tumour size among both pre- and postmenopausal women (Phet = 0.05 and 0.0001, respectively). None of these relationships were explained by hormone receptor status of the tumours. In conclusion, these data support distinctive risk factor relationships by tumour characteristics of prognostic relevance. These findings might be useful in developing targeted prevention efforts.

Prion protein gene M129 allele is a risk factor for Alzheimer's disease.

Prion protein gene polymorphism M129V represents a known risk factor for Creutzfeldt-Jakob disease. Recently, the meta-analysis revealed that homozygosity at codon 129 is connected with increased risk of Alzheimer's disease (AD). To determine whether M129V polymorphism is a risk factor for AD we analyzed a group of early-onset, and late-onset Polish AD patients. We observed that in LOAD patients there is a statistically significant increase of MM (p=0.0028) and decrease of MV (p=0.0006) genotype frequency, as compared to controls. When both groups were stratified according to APOE4 status, increase of MM and decrease of MV genotype frequency were significant in the LOAD subgroup with no APOE4 (p=0.017, and p=0.018, respectively). In the subgroup with APOE4 allele, only MV genotype frequency was significantly lower, as compared to controls (p=0.035). However, no interaction was found between APOE4 status and M129V polymorphism. We conclude that MM genotype increases LOAD risk in Polish population independently from the APOE4 status.

The -22c/t polymorphism in presenilin 1 gene is not connected with late-onset and early-onset familial Alzheimer's disease in Poland.

The -22c/t polymorphism in the promoter of the presenilin 1 gene is associated with increased risk for Alzheimer's disease (AD) in some populations. It was shown that -22c allele is connected with two-fold decrease in promoter activity. We studied the impact of the polymorphism in groups of Polish late-onset and early-onset AD patients. Our results suggest that -22c/t polymorphism is not connected with AD in Polish population. The -22t allele showed a high degree of linkage disequilibrium with -2797 insertion of 13 bp. An additional -2923g/t polymorphism is also not connected with -22c/t and is not a risk factor for AD.

Association of apolipoprotein E and myeloperoxidase genotypes to clinical course of familial and sporadic multiple sclerosis.

The importance of apolipoprotein E (ApoE) and myeloperoxidase (MPO) genotypes in the clinical characteristics of multiple sclerosis (MS) has been recently emphasized. In a large group of Polish patients we have tested the hypothesis that polymorphism in ApoE and MPO genes may influence the course of the disease. Genotypes were determined in 117 MS patients (74 females and 43 males; 99 sporadic and 18 familial cases) with mean EDSS of 3.6, mean age of 44. 1 years, mean duration of the disease 12.8 years and mean onset of MS at 31.2 years, and in 100 healthy controls. The relationship between ApoE and MPO genes' polymorphism and the MS activity as well as the defect of remyelination (diffuse demyelination) and brain atrophy on MRI were analysed. The ApoE epsilon4 allele was not related to the disease course or the ApoE epsilon2 to the intensity of demyelination on MRI. The genotype MPO G/G was found in all familial MS and in 57% (56/99) of sporadic cases. This genotype was also related to more pronounced brain atrophy on MRI. The MPO G/G subpopulation was characterized by a significantly higher proportion of patients with secondary progressive MS (P < 0.05) and by a higher value of EDSS. According to our results the MPO G allele is frequently found (in 96% of cases) among Polish patients with MS. More severe nervous tissue damage in the MPO G/G form can be explained by the mechanism of accelerated oxidative stress. It seems that MPO G/G genotype may be one of the genetic factors influencing the progression rate of disability in MS patients.