CLU gene (rs11136000) has been associated with the risk for Alzheimer’s disease (AD). CLU C allele is assumed to confer risk for AD and the allele T may have a protective effect. We investigated the influence of the AD-associated CLU genotype on a common neurophysiological trait of brain activity  in non-demented adults and elucidated whether this influence is modified over the course of aging. We examined quantitative electroencephalography (EEG) in a cohort of non-demented individuals (age range 20–80) divided into young (age range 20–50) and old (age range 51–80) cohorts and stratified by CLU polymorphism. To rule out the effect of the apolipoprotein E (ApoE) genotype on EEG characteristics, only subjects without the ApoE ε4 allele were included in the study. The homozygous presence of the AD risk variant CLU CC in non-demented subjects was associated with an increase of alpha3 absolute power. Moreover, the influence of CLU genotype on alpha3 was found to be higher in the subjects older than 50 years of age. The study also showed age-dependent alterations of alpha topographic distribution that occur independently of the CLU genotype. The increase of upper alpha power has been associated with hippocampal atrophy in patients with mild cognitive impairment (CLU CC-dependent increase in upper alpha rhythm, particularly enhanced in elderly non-demented individuals, may imply that the genotype is related to preclinical dysregulation of hippocampal neurophysiology in aging and that this factor may contribute to the pathogenesis of AD.Polymorphism in the genomic region harboring the pairment . In our  The incidence and prevalence of AD begins to rise as individuals reach the age of 65, so that by the time they are in their 80s and 90s the risk of clinical dementia is nearly 50%.Alzheimer’s disease (AD) is the major cause of dementia in the elderly. It is estimated that 35.6 million people worldwide currently suffer from dementia, with the prevalence projected to increase to 65.7 million by 2030 and 115.4 million by 2050. Two-thirds of these people will likely develop AD (ApoE), located on chromosome 19, has been established as the most common genetic risk factor for AD in Caucasian ethnic groups, including the Russian population (Alzheimer’s disease has a strong genetic basis with heritability estimates of up to 80% . Mutatiopulation .CLU) (chr8) and PICALM (chr11) genes are also associated with AD risk  studies have provided evidence that polymorphisms of the clusterin  chaperones to alter Aβ aggregation and/or clearance  genotype and the gene encoding gamma-aminobutyric acid B (GABAB) receptor both influence alpha voltage  patterns are considered to be valuable as an endophenotype – a more basic biological trait that more directly reflects the influence of the genome . The her voltage .Testing the association of the AD risk alleles with EEG endophenotypes can help understand where in the brain, in which stage, and during what type of information processing the genetic variant has a role.Quantitative EEG (qEEG) has been shown to be a reliable diagnostic tool in dementia research . SlowingAlterations of alpha rhythm in particular were found to be related to AD development. In a resting-state condition, posterior alpha rhythms showed a power decrement in patients with MCI as compared with healthy elderly subjects , 2014. IApoE ε4 and EEG in patients with AD, MCI, and healthy subjects  in the brain regions intrinsic to memory processes, and faster rates of decline in verbal memory performance scores  would show age-dependent alpha-rhythm alterations relative to carriers of the protective T allele (heterozygous CLUCT and homozygous CLUTT genotypes).We tested the hypothesis that healthy adult carriers of the AD risk variant The enrolled cohort included 87 non-demented individuals . All subjects were of Russian origin from Moscow and the Moscow region. Participants underwent a neurological examination and cognitive screening. The recruited subjects were free of dementia and other medical, psychiatric, and neurological conditions. Exclusion criteria included a personal history of mental illness, signs of clinical depression or anxiety, physical brain injury, neurological disorder, or other medical condition , and a personal history of drug or alcohol addiction. The Spielberger state-trait anxiety inventory  and HamiInformed written consent was obtained from all participants. The experimental protocol of this study was approved by the local Ethics Committee.ApoE genotyping was performed on all participants, and to exclude the effect of the ApoE genotype on EEG characteristics, only subjects without the ApoE ε4 allele were included in the study.CLU (CLU CC and CLUCT&TT) polymorphism. The homozygous CLU CC group included subjects with two C alleles of CLU, and the CLU CT&TT group consisted of subjects with heterozygous CLU CT or homozygous CLU TT genotypes. The participants with CLU CC as well as with CLU CT&TT genotypes were also divided into cohorts of those younger and older than 50 years of age.All subjects were divided into subgroups according to All recordings were obtained in the afternoon at 3–4 pm. During the experiments, the subjects sat comfortably in a chair. They were asked to close their eyes and to relax during the recording. The technician watched the subject’s vigilance state continuously by monitoring the EEG and observing the subject.The registration and evaluation of EEG has been carried out in accordance with the International Pharmaco-EEG Society (IPEG) guidelines . EEGs weThirty-six to forty artifact-free 4-s epochs of resting EEG were processed by fast Fourier transform. Absolute power for the frequencies of interest: alpha1 (7.5–8.99), alpha2 (9.00–10.99), alpha3 (11–12.99), and for the regions of interest (ROI): occipital , frontal 1 , frontal 2 , temporal 1 , and temporal 2  were calculated.These alpha band frequencies were chosen by averaging those used in previous relevant EEG studies on aging, genetic influences, and dementia ,b. This Log transformations of the absolute power of the various bandwidths in each derivation were calculated in order to compensate for data skewness, as recommended by Genomic DNA was isolated from peripheral venous blood by the standard phenol–chloroform extraction methodology, or by using a Qiagen kit for DNA isolation. Genotyping was performed by polymerase chain reaction (PCR) and followed by restriction fragment length polymorphism (RFLP) analysis. Amplification was performed according to the manufacturer’s instructions using both the Tercyc DNA amplifier  and the GeneAmp PCR System 9700 Thermal Cycler (Applied Biosystems).APOE gene locus, the following oligonucleotide primers were used: 5′_CGGCTGGGCGCG_GACATGGAGGA and 5′_TCGCGGGCCCCGGC_CTGGTACAC. The PCR protocol was as follows: preliminary denaturation at 95°C for 4 min; 5 cycles: 95°C for 45 s, 54°C for 25 s, and 72°C for 30 s; and 30 cycles: 95°C for 5 s, 58°C for 15 s, and 72°C for 5 s; the last stage was performed at 72°C for 3 min. PCR products were then cleaved by HhaI or BstHHI  and restriction products were analyzed in 7.5% polyacrylamide gel.To genotype the rs11136000 polymorphism in CLU gene was tested with the following oligonucleotide primers: 5′_CTTTGTAATGATGTACCATCTACCC and 5′_AGGCTGCAGACTCCCTGAAT. The PCR protocol was as follows: preliminary denaturation at 95°C for 1 min and 35 cycles: 94°C for 30 s, 57°C for 30 s, and 72°C for 1 min. The last stage was performed at 72°C. The 645 bp PCR products were then cleaved by AcsI restriction endonuclease  and restriction fragments were analyzed in 2% agarose gel.The CLU CC young, CLU CT&TT young, CLU CC old, CLU CT&TT old) were tested using analysis of variance (ANOVA) for continuous variables , and the Mann–Whitney U test for categorical variables (sex).Differences in demographic scores between the groups (CLU CC vs CLU CT&TT) and Age cohort (old vs. young) as between-subjects factors, and ROI: occipital , frontal 1 , frontal 2 , temporal 1 , temporal 2 , and hemisphere  as a within-subject factor. Post hoc comparisons for between-subject effects and within-subject effects were analyzed using the Duncan test, and the level of significance was set to P < 0.05 for post hoc comparisons.Electroencephalography parameters from each group were tested for the normal distribution by the Wilk–Shapiro test, and in no cases were the data skewed. The significance of the differences between the log-transformed EEG parameters was estimated using repeated measures of ANOVA in the general linear model (GLM) separately for alpha1, alpha2, and alpha3 bands, with Genotype (Table 1 shows the demographic information for the participants. There were no differences in age and sex between the CLU CC and CLU CT&TTsubgroups in either the young or the old subgroups and in the whole sample (P > 0.05). There were no significant differences in sex between the young and the old subgroups with the same CLU genotype.F = 111.97, P = 0.0000; for alpha2, F. Post hoc comparisons showed that in the entire sample, which included young and old cohorts, absolute power was higher in occipital than in frontal and temporal regions in the alpha1, alpha2, and alpha3 bands (P < 0.0001). Moreover, the power of all alpha bands was higher in frontal as compared to temporal areas (P < 0.0001).The ANOVA revealed a significant effect of ROI on alpha1, alpha2, and alpha3 absolute power , but such an effect was observed on alpha2 and alpha3 bands . In the old cohort, the differences in alpha2 power between the ROI were reduced. Whereas in the young cohort, alpha2 power was higher in frontal Fp than in temporal posterior Tp areas (post hoc comparisons P = 0.002), in the old cohort the differences in these areas were not significant (P = 0.11). The differences between frontal Fp and temporal posterior Tp areas were significantly smaller in the old than in the young cohort .There was no significant statistical Age × ROI interaction effect on alpha1 power (P = 0.02); in the old cohort these differences were not significant (P = 0.1), and age-related changes of these regional differences were also not significant. Alpha3 power was lower in the occipital ROI in the old cohort as compared to the young .Similarly, in the old cohort, the differences in alpha3 power between ROI were reduced as compared to the young cohort. In the young cohort, alpha3 power was higher in temporal posterior than in temporal areas . In the young subjects, alpha2 power was significantly higher than alpha1 and alpha3 power (P = 0.00001), while in the old subjects the alpha1 power tended to increase and the differences between alpha1 and alpha2 power were not significant .A significant interaction effect between the factors Age and Bands was observed , but not on alpha1  or alpha2  absolute power. Post hoc comparison revealed that in the entire sample, which included old and young cohorts, alpha3 absolute power in the subjects with homozygous CLU CC genotype was significantly higher than in the subjects with heterozygous CLU CT and homozygous CLU TT (CLU CT&TT) genotypes (P = 0.017). Moreover, post hoc comparison showed that, in the old cohorts, alpha3 power was significantly higher in the CLU CC than in the CLU CT&TT carriers (P = 0.016), while in the young cohorts the differences in alpha3 power between the CLU CC and CLU CT&TT carriers did not reach a significant level . There were no significant differences in alpha1 and alpha2 power between the young CLUCC and CLUCT&TT carriers . In the old cohorts, alpha1 power was higher in the CLUCC than in the CLUCT&TT carriers (P = 0.04), while the differences of alpha2 power in the old CLUCC and CLUCT&TT carriers were not significant .The results of ANOVA showed that the main effect of CLU CC and CLU CT&TT carriers were observed in alpha3 power in the old cohorts. In the young cohorts, there were no significant differences in any ROI in alpha1, alpha2, and alpha3 power between CLU CC and CLU CT&TT carriers . In the old cohort the differences between CLU CC and CLU CT&TT carriers were significant for alpha1 power in occipital (P = 0.02) and temporal posterior areas (P = 0.02), for alpha3 power – in frontal (P = 0.04), frontal poles (P = 0.03), and temporal posterior (P = 0.02) areas .Topographic analysis demonstrated that the most pronounced differences between the homozygous CLU × ROI interaction effect on the alpha1 power in the entire sample was observed . In the CLU CC carriers alpha1 power was higher in occipital than in frontal areas (P < 0.0001) and in temporal posterior than in temporal areas (P = 0.001), while in the subjects with CLU CT&TT genotypes the differences in alpha1 power between occipital and frontal areas were smaller (P = 0.01), the differences between the temporal posterior and temporal areas were not significant (P = 0.3). There was a tendency toward higher alpha1 power in all ROI in the subjects with CLU CC genotype as compared to the subjects with CLU CT&TT genotype.A significant CLU genotype exerts a significant effect on alpha absolute power in the resting-state EEG of healthy adults. The homozygous presence of the AD risk variant CLU CC in non-demented subjects was associated with an increase of alpha3 and to a lesser, though significant, extent of alpha1 power in the subjects older than 50 years of age. CLU genotype-related differences were also found in the topographic distribution of alpha1 activity: in the subjects with homozygous CLU CC genotype, alpha1 power was higher in occipital than in frontal regions, while in the subjects with heterozygous CLU CT and homozygous CLU TT (CLU CT&TT) genotypes the differences in alpha1 power between occipital and frontal regions were not significant. The present study also showed age-related alterations of the topographic distribution of alpha2 and alpha3 activities, and an age-related increase in power of alpha1 relative to alpha2, all of which occurred in the subjects with CLU CC as well as with CLU CT&TT genotypes.The main findings of this study show that the Alpha rhythm reflects the activity of dominant oscillatory neural networks in resting adults and represents a basic functional feature of the working brain . Alpha oInhibitory processes underlie alpha synchronization . During According to prior research in this area, alpha rhythm is not a unitary phenomenon. Upper alpha (11–13 Hz) is more involved in cortical processes related to the semantic memory and low alpha (8–11 Hz) is more involved in attentional demands . DiffereRecent study has shown an increase of the upper alpha power in patients with MCI and AD, when compared to normal elderly subjects ,b. The iCLU CC, especially old subjects with this genotype, may have similar, though less pronounced, alterations underlying the increase of upper alpha activity to those found in MCI subjects. These alterations may include the dysregulation of excitatory synaptic inputs, especially cholinergic ones, in hippocampus and frontal intracortical networks. In the old CLU CC carriers we also found an increase in alpha1 power, though less pronounced, than in alpha3 power. These finding suggest that in the old CLU CC carriers the dysregulation may affect other mechanisms, such as corticothalamic, corticostriatal, and corticobasal ones, involved in low alpha generation (Healthy carriers of AD risk variant neration ,b.Even normal aging is accompanied by a gradual loss of cholinergic function caused by dendritic, synaptic, and axonal degeneration as well as a decrease in trophic support. As a consequence, impairments in intracellular signaling and cytoskeletal transport may mediate cholinergic cell atrophy, finally leading to the known age-related functional decline in the brain, including aging-associated cognitive impairments .CLU genotype, aging is accompanied by changes in spectral power and topographic distribution of alpha activity (In line with previous studies, our results also demonstrated that in all individuals, independently of activity . We founactivity . A slowiactivity . The antactivity . It was activity . Chronicactivity . On the activity . The braactivity .CLU genotype on brain function may be observed before the onset of cognitive impairment. The CLU risk variant rs11136000 was found to be associated with reduced integrity of broad white matter regions, as observed with diffusion tensor imaging in young healthy adults (CLU AD risk genotype (The effect of aging on EEG is modulated by genetic factors . Severaly adults . fMRI stgenotype .C-allele of the rs11136000 SNP were revealed (CLU CC genotype may be related to the deposition of beta amyloid, and that affected regions are vulnerable to disruption by deposition of beta amyloid, even in the non-demented elderly.Recently the robust changes in rCBF in cognitively normal old individuals carrying the revealed . These cCLU genotype on resting EEG in healthy subjects was not similar to the effect of ApoE genotype found in prior studies (CLU and ApoE genotype on resting rCBF in normal aging (CLU CC carriers and the decrease in resting rCBF in the frontal, parietal, and temporal cortices and its increases in the insular cortex in the old ApoE ε4 carriers.The effect of  studies . The difal aging . The autCLU genotype-related differences were found in the age-adjusted groups, this possible confounding factor could not affect the results concerning the influence of CLU genotype on alpha power.Alpha rhythm slowing was found to occur in aging, and the alpha1 band of the young group might have some functional differences from the alpha1 band in the old subjects . This isCLUCC, AD risk variant, is associated with increased absolute power of alpha3 activity and changes in topographical distribution of alpha1 activity and that this effect is more pronounced in the subjects older than 50 years of age. The increased synchronization of upper alpha activity may be related to the alterations in cholinergic hippocampal and cortical networks. The effect of CLU genotype on alpha activity can be superimposed to the other EEG alterations that occur across physiological aging.Our results show that the presence of the homozygous The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.


Brain-derived neurotrophic factor (BDNF) plays a role in the maintenance and function of neurons. Although persons with Alzheimer’s disease have lower cortical levels of BDNF, evidence regarding the association between circulating BDNF and cognitive function is conflicting. We sought to determine the correlates of BDNF level and whether BDNF level was prospectively associated with cognitive decline in healthy older adults. We measured serum BDNF near baseline in 912 individuals. Cognitive status was assessed repeatedly with the modified Mini-Mental Status Examination and the Digit Symbol Substitution test over the next 10 years. We evaluated the association between BDNF and cognitive decline with longitudinal models. We also assessed the association between BDNF level and demographics, comorbidities and health behaviors. We found an association between serum BDNF and several characteristics that are also associated with dementia (race and depression), suggesting that future studies should control for these potential confounders. We did not find evidence of a longitudinal association between serum BDNF and subsequent cognitive test trajectories in older adults, although we did identify a potential trend toward a cross-sectional association. Our results suggest that serum BDNF may have limited utility as a biomarker of prospective cognitive decline. Brain-derived neurotrophic factor (BDNF) is one of a family of neurotrophins which play an important role in the development, maintenance and function of neurons The research community hoped that circulating BDNF could provide a less invasive, inexpensive biomarker for dementia; but so far, there is conflicting evidence in the literature regarding the association between BDNF and cognition decline and dementia. Some studies indicate serum BDNF is higher in controls than persons with mild cognitive impairment (MCI), AD or dementia In this analysis, our goal was two-fold. First, we aimed to elucidate correlates of BDNF, as they show some inconsistencies in the literature. Substantial evidence supports an association between depression and lower serum BDNF but evidence regarding correlations between BDNF and basic characteristics like sex, age, and BMI is equivocal. Second, we aimed to evaluate the association between BDNF and cognitive decline, especially after consideration of potential confounders using a large prospective cohort of cognitively healthy older adults with cognitive performance evaluated at multiple time points over a lengthy follow-up. The cohort is biracial (black and white) which allows examination of possible differences in BDNF by race, which other studies have lacked sufficient diversity to address.The Institutional Review Boards at all clinical sites  and the University of California – San Francisco coordinating center approved the study protocol and all participants signed informed consent.Participants were enrolled in the Health, Aging and Body Composition  study, a prospective cohort of 3075 community-dwelling black and white older adults living in Memphis, Tennessee and Pittsburgh, Pennsylvania. Participants were recruited from a random sample of Medicare-eligible adults living within designated zip codes. Participants were eligible if they reported no difficulties performing activities of daily living, walking a quarter mile, climbing 10 steps without resting, were free from life-threatening cancers, and planned to remain in the study area for at least 3 years. All patients signed an informed consent form that was approved by the institutional review boards of each clinical site and the data coordinating center. Serum BDNF levels were measured in a subset of 1000 participants, selected by stratified random sample, excluding those with possible dementia (3MS <80 at baseline). The BDNF measurements for 77 participants were missing for technical reasons, and 11 participants were missing cognitive testing at included time points leaving an analytical sample of 912.Serum BDNF was measured at the first follow-up visit (year 2). Fasting blood samples were obtained by standard venipuncture with serum was stored at −70°C and shipped directly to the analytical laboratory in Minneapolis, MN. Assays were performed by R&D Systems’ Analytical Testing Service, employing an enzyme-linked immunosorbent assay method. The detection limit for this assay is 1250 pg/mL. The mean inter-assay coefficient of variation is 9.2% and the mean coefficient of variation within assay is 6.5%. Covariates examined were assessed at year 2 where available. If unavailable, assessments from an adjacent year were used . Participants were considered depressed if they scored greater or equal to 16 on the Center for Epidemiologic Studies Depression Scale (CES-D) at baseline or reported treatment for depression at baseline (medication verified). Potential covariates included demographic characteristics, cardiovascular comorbidities, Apolipoprotein ε4 carrier status, BDNF Val66Met Met(A) carrier status (SNP rs6265), health behaviors, and platelet count, which was previously found to be an important predictor of BDNF After examining the distribution of the BDNF measurements and finding a limited number of extreme values, we trimmed the data to exclude the top and bottom 1% to reduce the possibility of influential observations outside of the typical range unduly impacting the model results. This excluded ten values at or above 47.3 ng/mL (range: 47.3–63.1) and ten values at or below 5.5 ng/mL (range: 2.3–5.5), resulting in a final data range of 5.6 ng/mL –47.25 ng/mL. The association between BDNF and participant demographic and comorbid characteristics was characterized using BDNF tertiles and tested with Chi-square tests and ANOVA, where appropriate. We constructed a multivariate linear regression model using covariates with p<0.20 to examine the association between predictors and BDNF after simultaneous adjustment.We assessed the relationship between BDNF and cognitive test scores using linear mixed-effects regression models with random slopes and intercepts. BDNF and platelet count were standardized so that coefficients could be interpreted as change in cognition associated with a one standard deviation increase in BDNF or platelet count. We examined the relationship in both unadjusted and adjusted models. The adjusted model contained covariates which differed significantly between BDNF tertiles (p≤0.05), covariates which were significant predictors of BDNF in the adjusted model (p≤0.05), and other covariates known to be important in modeling cognitive scores .BDNF measurements were generally normally distributed with a small number of extreme values in the right tail. As such, the data was trimmed to exclude the top and bottom 1% of BDNF observations. BDNF tertiles were significantly associated with platelet count, sex, race, Met carrier , history of MI, and smoking . FemalesThe median number of 3MS observations per person was 4 (range: 1–5); the median number of DSST observations per person was 3 (range: 1– 4). In both unadjusted and adjusted analyses, we found no significant association between BDNF and performance on either cognitive test, cross-sectionally or longitudinally . There wSerum BDNF showed strong associations with race, platelet count, and depression after adjusting for other factors, and weak associations with a number of other participant characteristics. We found that blacks had higher levels of BDNF than whites, a unique finding which has not been addressed in the literature so far. It is unclear whether the race differential in BDNF is due to unmeasured factors differing between blacks and whites or true biological differences. The strong association between BDNF and platelet count is consistent with theory that BDNF in serum is derived directly from platelets. Age did not differ significantly among serum BDNF tertiles which is in concordance with results from some studies 2 = 0.03, n = 27); however, a study comparing blood and BDNF levels in pigs and rats found significant positive correlation between the two in both pigs and rats  We did not identify any longitudinal associations between BDNF and cognition; this is in agreement with the other longitudinal study of blood based BDNF in cognitively normal older adults Comparison of our raw and adjusted analyses demonstrates that confounders may have a profound effect on the estimate of the relationship between BDNF and cognition, particularly cross-sectionally. Many previous studies chose to use nonparametric group tests due to concerns that the BDNF distribution showed departures from normality. While extreme values and departures from normality are a concern, our results suggest that confounding may be a much greater concern, especially in the presence of an adequate sample size.Strengths of this analysis include the prospective nature of the study, large biracial sample, and ability to control for multiple potential confounders. This analysis was limited by data collection occurring at different time points for some variables, such as platelet count. The negative impact of this is likely minimal as no covariate assessment occurred more than a year from BDNF blood draw and comparisons of platelet counts measured in years 3 and 11 suggest high intra-person correlation of platelet count over time (Spearman correlation coefficient 0.73). It is possible that our relatively healthy sample of older adults without dementia at baseline lacked sufficient variability in BDNF to detect associations reported elsewhere, although the serum BDNF range exhibited in our data is consistent with other similar studies. There is evidence that treatment for depression raises BDNF levels After adjustment for confounding, our analysis provides no evidence that serum BDNF is prospectively associated with decline on DSST or 3MS. We found that serum BDNF was associated with a number of characteristics which also associated with dementia, which suggests that future studies should control for these potential confounders.


Glyoxalase 1 is a scavenging enzyme of potent precursors in reactive oxygen species formation and is involved in the occurrence and progression of human malignancies. Glyoxalase I A111E polymorphism has been suggested to influence its enzymatic activity. The present study was aimed at investigating the association of this polymorphism with oxidative stress and its implications in prostate cancer progression or survival. The polymorphism was genotyped in human differently aggressive and invasive prostate cancer cell lines, in 571 prostate cancer or 588 benign prostatic hyperplasia patients, and 580 healthy subjects by Polymerase Chain Reaction/Restriction Fragment Length Polymorphism. Glyoxalase 1 activity, the pro-oxidant Glyoxalase 1-related Argpyrimidine and oxidative stress biomarkers were evaluated by biochemical analyses. Glyoxalase 1 polymorphism was associated with an increase in Glyoxalase 1-related pro-oxidant Argpyrimidine and oxidative stress levels and cancer progression. The mutant A allele conferred a modest risk of prostate cancer, a marked risk of prostate cancer progression and a lower survival time, compared to the wild C allele. The results of our exploratory study point out a significant role for Glyoxalase 1 in prostate cancer progression, providing an additional candidate for risk assessment in prostate cancer patients and an independent prognostic factor for survival. Finally, we provided evidence of the biological plausibility of Glyoxalase 1 polymorphism, either alone or in combination with other ones, all related to oxidative stress control that represents a key event in PCa development and progression. Glyoxalase 1 (GLO1) is a glutathione-dependent enzyme involved in the scavenging of Methylglyoxal (MG), a potent cytotoxic α-oxoaldehyde, with a strong ability to cross-link with protein amino groups, forming stable products called advanced glycation end products (AGEs) The results of our exploratory study point out a significant role for GLO1 in PCa progression, providing an additional candidate for risk assessment in PCa patients and an independent prognostic factor for survival.2 in RPMI 1640 supplemented with 10% heat inactivated FBS, 1X L-glutamine, 1 mM sodium pyruvate, 1X non-essential amino acids, 100 units/ml of penicillin and 0.1 mg/ml of streptomycin (Invitrogen).Human prostate cancer LNCaP and PC3 cell lines were obtained from American Type Culture Collection (ATCC) and routinely maintained at 37°C in 5% COA total of 1739 Caucasian Italian men were enrolled in this study. Of them, 1423  were enrolled between April 1999 and June 2005 from the Department of Urology , 316  were recruited between July 2005 and June 2013 from the same Department. The case group consisted of 571 patients with previously untreated, histologically verified PCa, diagnosed by transrectal ultrasound-guided biopsies. The indication for prostate biopsy was either a suspicious finding on digital rectal examination or elevated serum levels of Prostate Specific Antigen (PSA), or both. Disease was classified according to the World Health Organization criteria and staged according to the Tumour Node Metastasis (TNM) classification and the Gleason grading system (Gleason score). In particular, we stratified the analysis according to tumour stage  and histological grade , according to the pathologic and/or radiologic reports. Evidence suggests that prostate tumours designated as Gleason score of 7 differ quite distinctly in regard to prognosis with those tumours with a Gleason score of 3+4 = 7 considered less aggressive than tumours with a Gleason score of 4+3 = 7 All subjects gave written informed consent to the study, which was approved by the Committee on Bioethics of the University of Perugia in accordance with the principles established in the Helsinki declaration.DNA from peripheral blood leukocytes was extracted with the NucleoSpin Blood Quick Pure Kit (Macherey-Nagel). GLO1-419C>A SNP detection was based upon Polymerase Chain Reaction-Fragment Length Polymorphism (PCR-RFLP) analysis as previously described Single nucleotide polymorphisms (SNPs) for the oxidative stress control-related genes Glutathione S-transferase 1 , Paraoxonase 1  and cytochrome P450 17 (CYP17A1> A2) were detected as described by Antognelli et al. Collection of urine samples was performed as previously described Serum, plasma and lymphocytes were obtained from blood samples collected prior to rectal palpation, to exclude the possibility of influencing the results due to prostate manipulation. Serum and plasma were obtained according to standard protocols and used for GLO1 or MDA and GSH measurements, respectively. Lymphocytes were isolated in Lymphoprep separation medium  Preparation of extracts from cell lines and GLO1 enzymatic specific activity were according to Antognelli et al. Whole-cell protein extraction and western blot were performed as previously described ROS and GSH were detected according to Szabados et al. 2 test was used to compare genotype/allele frequencies between PCa cases and BPH or healthy subjects controls. Odds ratio (ORs) was calculated to estimate the Relative Risk for PCa by unconditional logistic regression analysis and adjusted for potential modifying factors, including age (continuous) and Prostate-specific antigen . Allele frequencies were calculated by direct gene counting. χ2 test was used for testing of Hardy-Weinberg equilibrium (HWE). GLO1 SNP was tested for possible effects on oxidative stress control-related traits by linear regression analysis under an additive model, incorporating covariates of age and PSA. Survival analysis of selected PCa cases was used to test the possible effect of genotypes on the risk of dying from PCa. For this purpose survival curves were constructed using the Kaplan-Meier method, and the differences between the groups were tested by the log-rank method. The multivariate analysis of the probable prognostic factors for survival was performed using Cox’s proportional hazard regression analysis. The relative hazard ratios (HR) with 95% confidence intervals were assessed adjusting for potential confounding variables, so considered if they changed the HRs of any of the genetic variants by at least 5%. Survival time was calculated from the dates of PCa diagnosis to the date of PCa-specific death, collected from the databases of the Regional Cancer Registry in 2010. Adjustment for multiple testing was performed using permutation-based methods Analysis of data was performed using SPSS 11.0 for Windows. Descriptive analysis included determination of standard deviation (SD) as well as Student’s t-test. GLO1 serum levels were log-transformed as the subgroups  were not showing normal distribution of the data as per 1 sample-KS test. Distribution of metabolites was normal in each of the above mentioned subgroups. The χThe main characteristics of PCa cases and BPH or healthy controls are presented in in vitro results appeared to support the potential association of GLO1 polymorphism with progression, we performed measurements of the same parameters in blood samples and cells from urine sediments of patients with localized and locally advanced or low, intermediate and high grade PCa. GLO1 activity, AP and oxidative stress indices, both in blood or cells from urine sediments, were significantly different among PCa patients stratified by stage and grade, carrying CC, CA and AA genotypes of GLO1 polymorphism   , reflectA study on the association of GLO1 polymorphism and PCa risk was also performed.The genotype and allele frequencies of GLO1 −419C>A polymorphism in PCa cases and BPH or healthy controls are shown in Since a significant percentage of patients with localized 60.6%,  or low gIn addition, the multivariate analysis used to delineate significant prognostic factors for survival, showed in both subgroups that the risk A allele was an independent prognostic factor for survival after adjustment for age and PSA  .In a case/control study whose cohorts has now been included in the present enlarged populations, we previously found that polymorphisms in oxidative-stress control-related GSTP1, PON1-192, PON-1 55 and CYP17 genes were associated with the risk of PCa. In that work, no association of the same gene polymorphisms was found with tumor progression or survival Multiple comparisons were necessary before an overall definitive statement about the significance of our findings could be made. All results, except those on the association of GLO1 polymorphism with PCa risk, withstood correction for multiple testing (p<0.05).In the present study we evaluated, for the first time to our knowledge, the association between GLO1 −419C>A polymorphism and oxidative stress levels in PCa progression.In fact, as previously suggested, the A to E substitution due to GLO1 SNP may determine a conformational modification in the enzyme, leading to an isoenzyme with a lower detoxification capacity As to survival analysis, we found that GLO1 −419 A allele was significantly associated with an unfavourable survival prognosis in patients with localized (T1/T2) or low grade (GS 2–6) PCa. Therefore, if confirmed by additional studies, this polymorphism, preferably in combination with others, might help to differentiate between clinically significant and indolent prostate cancers and to predict the clinical course of early stages PCa. Unfortunately, the additional polymorphisms studied in the present work, either singly or in combination, did not show any significant association with PCa survival or progression. The combination was, however, significant in the association with PCa risk and positively correlated with the oxidative stress status shown by patients belonging to specific risk classes, thus providing biological plausibility. In fact, such genes encode proteins related to the control of oxidative stress, being able to detoxify free radicals (PON 1 and GSTP1) or reduce potential substrates for their production (CYP17). Similarly to GLO1, the polymorphic variants may determine conformational modifications leading to isoenzymes with an altered functional capacity and, consequently, contributing to the onset of a marked oxidative stress condition as, indeed, here, pointed out by the genetic association with blood or urinary levels of oxidative stress indices.p value stayed still significant <0.05 after correction for multiple testing using permutation-based methods) for all the other analyses, indicating the robustness of the results.It is now well accepted that genetic association studies have helped enhance our understanding of the pathogenesis of human cancers, including PCa. However, establishing the clinical utility of these SNPs have proven challenging mainly because of the difficulties encountered in performing SNP analysis  In conclusion, our study pointed out a significant role for GLO1 in PCa progression and that GLO1 −419A risk allele may be an independent prognostic factor for survival. Finally, we provided evidence of the biological plausibility of such polymorphism, either alone or in combination with other ones, all related to oxidative stress control that, as known, represents a key event in PCa development and progression. Since this is the first study examining the association between GLO1 −419C>A polymorphism and PCa, additional research is required.


N = 130 healthy participants an online version of the UG was conducted and polymorphisms of the dopamine D2 receptor gene (DRD2) and the DRD4 exon III VNTR were genotyped. We could confirm the DRD4 exon III effect on the responder behavior and the absence of an effect on the proposer behavior reported before. In line with Zhong et al. (p = 0.023) than subjects with any other genotype. Furthermore, a DRD2-haplotype-block containing the single nucleotide polymorphisms rs1800497 and rs2283265 was significantly associated with the amount player1 offered (p = 0.005) but not with the decision of player 2. Results support the importance of the dopaminergic system for pro-social behavior.One of the most prominent paradigms in neuroeconomics is the ultimatum game (UG) that provides a framework for the study of pro-social behavior in two players interacting anonymously with each other: Player 1 has to split an endowment with player 2. Player 2 can either accept or reject the offer from player 1. If player 2 accepts the offer then the money is split as proposed by player 1. In case of rejection both players get nothing. Until now only one twin study investigated the heritability of the behavior in the UG. Results indicated a strong heritability for the decision behavior of player 2 whereas no genetic influence on player 1 behavior could be detected. Further studies are mandatory to validate these heritability estimates. However, a first candidate polymorphism, the DRD4 exon III, constituting the biological basis of the heritability in the responder behavior has already been identified in a Chinese sample (Zhong et al., g et al.  carriers Game Theory player 2 should accept all offers greater than 0 €  and that his decisions are completely rational  that allow the investigation of human decision making under experimentally controlled conditions [for an overview see Camerer ]. One ofCamerer, . HoweverCamerer, , i.e., p Persky, . Instead Persky,  indicati Persky, . Whether Persky, . Indeed  Persky, . These d Persky, . The DRD Persky, . Three a Persky, . The VNT Persky, .2 receptor density . These data indicate that due to linkage the DRD2/ANKK1-Taq Ia polymorphism is indeed a marker for dopamine receptor density. The DRD/ANKK1-Taq Ia is the most prominent polymorphism with respect to the DRD2 gene. Mostly the minor A1 allele has been related to problematic or non-normative behaviour  replicate the reported association between the DRD4 exon III polymorphism and the responder behavior in the UG reported by Zhong et al. . HoweverN = 130 healthy subjects who are members of the Bonn Gene Brain Behavior Project  participated in the present study. The gender distribution was rather skewed [n = 105 females  and n = 25 males ] which is not surprising because most participants were psychology students at the University of Bonn and most of the psychology students in Germany are female (about 90%). The participants were not familiar with the UG (mainly 1st or 2nd year students participated). Gender groups did not differ with respect to age . The study was approved by the local ethics committee of the University of Bonn. All participants were completely debriefed on the aim of the study and the rules of the UG in advance of participation.The UG was conducted as an online experiment designed in a way that each participant played the game twice, first in the role of the first mover (splitting an amount of 10 € anonymously between himself and another player) and afterwards in the role of player 2 [declaring which minimum amount of money received from player 1 would be accepted by himself ]. The proposal in the role of the first mover and the minimal acceptable offer in the role of the second mover could be chosen in steps of 0.50 € ranging from 0 to 10 €. Each participant was informed about the consequences of each possible choice in either role: In the role of the first mover, he was instructed that if he for example chooses to send 4 € to the second mover the payoff will be 6 € for himself and 4 € for the interaction partner. Participants were informed that after the end of the study a lottery takes place that randomly builds couples of two players out of the total sample and assigns each participant his actual role in the game (first or second mover). The payoffs are than calculated based on the players' role (first or second mover) and the decisions they had taken before. The payoffs are actually given to the participants after the whole study was completed. There was no additional payment for participation. We contacted about 300 of the BGBBP of whom 130 provided data sets. The duration of the experiment was about 10 min.DNA was extracted from buccal cells. Automated purification of genomic DNA was conducted by means of the MagNA Pure® LC system using a commercial extraction kit . Genotyping of the three SNPs  was performed by real time PCR using fluorescence melting curve detection analysis by means of the Light Cycler System 1.5 . The primers and hybridization probes  were as follows:Forward primer: 5′-CGGCTGGCCAAGTTGTCTAA-3′Reverse primer: 5′-AGCACCTTCCTGAGTGTCATCA-3′Anchor hybridization probe: 5′-LCRed640-TGAGGATGGC-TGTGTTGCCCTT-phosphate-3′Sensor hybridization probe: 5′-CTGCCTCGACCAGCACT-fluorescein-3′DRD2/ANKK1 Taq Ia (rs1800497):Forward primer: 5′-GAACTTGTCCGGCTTTACC-3′Reverse primer: 5′-CAATCTTGGGGTGGTCTTT-3′Anchor hybridization probe: 5′-LCRed640-CCCCGCCAAACCAGAGAAGAAT-phosphate-3′Sensor hybridization probe: 5′-TCCACAGCACTCCCGACA-fluorescein-3′DRD2 c957t (rs6277):Forward primer: 5′-TCTTGGGCTAGACGCAT-3′Reverse primer: 5′-GTGGAATCCTCAAGACCACC-3′Anchor hybridization probe: 5′-LCRed640-CCTGTTTCCTCATCTGTTAAATGGGAAT-phosphate-3′Sensor hybridization probe [T]: 5′-TTAGGCAAGTTTCTTACCTTCTATGA-fluorescein-3′DRD2 rs2283265:DRD4 exon III:2, 10% DMSO, 2 U of Diamond Taq polymerase (Eurogentec) and the enzyme supplier's buffer. Amplification products were analyzed by 1.6% agarose gel electrophoresis. The sizes of the common 2-, 4-, and 7-repeats were 379, 475, and 619 bp, respectively. In n = 18 subjects genotyping of DRD4 exon III was not possible due to poor DNA quality. The RT-PCR method used for genotyping of SNPs is more sensitive than conventional PCR used for the VNTR. Therefore, valid data for the DRD4 exon III was only available in n = 112 subjects. In line with the study by Zhong et al. (n = 59) genotype were contrasted with the rest of the sample (n = 53). Therefore, the DRD4 genotype factor was entered into an ANOVA model with DRD4 as independent factor comprising two levels (4/4 vs. rest).The DRD4 exon III VNTR polymorphism was amplified from genomic DNA using polymerase chain reaction (PCR) and the primers 5′-TCCTCCGCTTTGGCGCCTCTTCC′ (forward) and 5′-TGGGGGTTGCAGGGGAGATCCTG-3′ (reverse). In brief, after an initial denaturation for 5 min at 94°C, 38 cycles of denaturing at 94°C for 30 s, annealing at 56°C for 30 s, and extension at 72°C for 1 min were followed by a final extension at 72°C for 4 min. PCR amplification was carried out in a final volume of 20 μl consisting of 50 ng genomic DNA, 0.25 mM of each desoxyribonucleotide, 0.5 μM of sense and antisense primers, 2.5 mM MgClg et al.  subjectshttp://www.broad.mit.edu/mpg/haploview/index.php). Individual haplotypes were calculated with PHASE, version 2.1. PHASE implements a Bayesian statistical method for reconstructing haplotypes from population genotype data. In simulation experiments it turned out that the mean error rate using PHASE was about half that obtained by the EM (expectation–maximization) algorithm  and the minimal acceptable offers (second mover)  were comparable to those reported in numerous other studies  = 0.494, p = 0.483] nor for the second-mover-behavior  and therefore gender was not included in the ensuing ANOVA models. It has to be pointed out that the absence of a gender effect may be caused by the small proportion of male subjects in our sample. Due to the homogenous student sample age was also not significantly correlated with the dependent variables. First and second mover behavior was significantly correlated  as it is the case in all UG studies. This means subjects who make fair offers in the role of the first mover have also higher minimal acceptance thresholds in the role of the second mover. The size of this correlation is invariant across genotype groups.Descriptive analyses of the UG data showed that the average first-mover-proposals ; DRD2 C957T (rs6277): T/T: n = 37, C/T: 61, C/C: n = 32 ; DRD2 rs2283265: G/G: n = 99, G/T: n = 27, T/T: n = 4 . The following genotype frequencies—that are also in HWE —were observed for the DRD4 exon III 48bp VNTR: 2/2: n = 2, 2/4: n = 13, 2/7: n = 3, 4/4: n = 59, 4/7: n = 25, 3/4: n = 6, 5/7: n = 1, 7/7: n = 3.The observed genotype frequencies for the three SNPs under investigation are all in Hardy-Weinberg-Equilibrium (HWE) and are as follows: DRD2 ANKK1/Taq Ia (rs1800497): A1/A1: M = 4.305, SD = 1.831) stated a significant higher minimal acceptable offer  than subjects with any other genotype  nor on the proposer behavior .We could confirm the DRD4 exon III effect on the responder behavior as reported by Zhong et al. . Carriersolid spine of LD method. However, the linkage between DRD2 ANKK1/Taq Ia (rs1800497) and DRD2 C957T was not satisfactory (D' = 0.52). The more conservative four gamete rule resulted in a two SNP haplotype block with the genetic markers DRD2 ANKK1/Taq Ia and rs2283265 spanning a distance of 15 kb  = 2.057, p = 0.090; η2 = 0.062]. An explorative descriptive analysis comparing the mean UG offers dependent on the haplotype genotypes revealed that all participants carrying at least one TT haplotype showed on average lower offers than carriers lacking the TT haplotype completely  = 8.102, p = 0.005; η2 = 0.060; see Figure An overall ANOVA model with the DRD2/ANKK1 haplotype as the independent variable and the first-mover-proposal as the dependent variable yielded a trend for a significant effect .An overall ANOVA model with haplotype as the independent variable and the second-mover-proposal as the dependent variable yielded no significant effect  on the first-mover-behavior was stronger than that of rs1800497 (DRD2 Taq Ia)  indicating that the association between rs1800497 is probably attributable to a strong linkage with the putative causal effect of rs2283265.The strategy to investigate several SNPs on the ANKK1/DRD2 gene simultaneously by means of a haplotype analysis is an elegant method to increase the amount of explained phenotypic variance. Ensuing univariate analyses help to identify the gene variant that drives the genetic effect. In the present study the effect of rs2283265 .The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.


It has been suggested that a common LRRK2 polymorphic variant (A419V (rs34594498 C >T)) may be a risk factor among Asians . In this study, we examined this variant in a larger and independent Taiwan cohort. We found the frequency of the variant (A419V) to be very rare in our Taiwan PD and controls (?0.6%). Further studies were conducted in two other Chinese populations (Singapore and China), comprising of a total of 3004 subjects including 1517 PD patients and 1487 control subjects. However, our multi-center Chinese study revealed that the frequency of the variant was rare (?0.4%) and was not associated with risk of PD, suggesting that the variant is not a major risk factor for PD among Chinese, at least in our study population. LRRK2/PARK8) were reported as a cause of PD in families with an autosomal dominant pattern of inheritance by two groups in 2004 LRRK2, probably due to the discovery of a common mutation (G2019S) Several pathogenic genes and susceptibility loci of Parkinson’s disease (PD) have been identified in both familial and sporadic cases in the last decade LRRK2 variants in three ethnic series , and identified a common polymorphic risk variant (A419V (rs34594498 C >T)) in 3 Asian cohorts (1376 Asian patients and 962 controls) Recently, investigators in a multi-center study genotyped 121 exonic The mean age at onset of PD in the three groups  was 63.0±11.2, 64±10, 60.1±11.0 years, and the mean age of control subjects at recruitment was 60.1±11.2, 59.9±9.8 and 60.2±13.2 years. The gender of the patient and control groups was matched in each cohort. All three cohorts showed similar minor allele frequency (MAF) of the SNP in the normal population (the frequency of 200 cases in Singapore was previously reported to be 0.4%) Our multi-center Chinese study, with a much larger sample size (>3000) than the previously reported Taiwan Chinese cohort (about 700) or combined mixed Asian cohort (>2300), showed the frequency of the variant was rare (?0.4%) and was not associated with risk of PD, suggesting that the variant is not a major risk factor for PD among Chinese, at least in our study population.LRRK2 protein and maybe functionally relevant to disease development, or it is in linkage disequilibrium with a non coding variant or the actual causative variant. As new loci susceptible to different complex diseases are continuously being discovered in genome-wide association and whole-genome sequencing studies, the results of our study demonstrate the importance of revisiting loci at which common or rare variants have been identified. It is possible that the A419V variant is a risk factor in only selected Asian populations or even subset of Chinese, unlike G2385R which has been consistently seen across all Chinese populations It’s intriguing why the results of ours and the other Taiwanese group in the multi-center study were markedly different All subjects gave written informed consent for this study under a protocol approved by local hospital internal ethics and scientific boards. .The diagnosis of PD was based on the UK PD Society Brain Bank clinical diagnostic criteria (more than one affected relative was excluded). Unrelated healthy adult volunteers matched for age, gender, ethnic origin, and area of residences were recruited as controls. We first recruited 485 PD patients and 494 control subjects in the Taiwanese Cohort and we found the frequency of the variant (A419V) to be very rare (∼0.6%). The subjects examined here did not overlap with the Taiwanese population included in the study performed by Ross et al R and sequence analysis from Singapore, and direct sequence analysis in the China cohort.TaqMan® Assays were used for SNP genotyping analysis in the Taiwanese cohort. Genotyping was carried out with mass spectrometric analysis using the SequanomChi square test was used to compare the frequency of the allele in both cases and controls. The genotypes of the case and controls followed the Hardy Weinberg equilibrium. Odds ratios and 95% confidence intervals were estimated. A free and open source software (OpenEpi) was used for the statistical analysis


Genome-wide studies have shown that polymorphisms on chromosome 4q25, 16q22 and 1q21 correlate with atrial fibrillation (AF). However, the distribution of these polymorphisms differs significantly among populations.To test the polymorphisms on chromosome 4q25, 16q22 and 1q21 in a group of patients (pts) that underwent catheter ablation of AF.Four hundred and ten patients with AF that underwent pulmonary vein isolation were included in the study. Control group (n = 550) was taken from healthy population, matched for age, sex and presence of hypertension. All participants were genotyped for the presence of the rs2200733, rs10033464, rs17570669, rs3853445, rs6838973 (4q25), rs7193343 (16q22) and rs13376333 (1q21) polymorphisms.All the polymorphisms tested (except rs17570669) correlated significantly with AF in univariate analysis , with the odds ratio (OR) 0.572 and 0.617 for rs3853445 and rs6838973, respectively (protective role) and OR 1.268 to 3.52 for the other polymorphisms. All 4q25 SNPs tested but rs3853445 were independently linked with AF in multivariate logistic regression analysis. In haplotype analysis six out of nine 4q25 haplotypes were significantly linked with AF. The T allele of rs2200733 favoured increased number of episodes of AF per month (p = 0.045) and larger pulmonary vein diameter .Patients qualified for catheter ablation of AF have a significantly higher frequency of 4q25, 16q22 and 1q21 variants than the control group. The T allele of rs2200733 favours larger pulmonary veins and increased number of episodes of AF. From the epidemiological perspective atrial fibrillation (AF) represents the most serious problem of all cardiac arrhythmias due to its high prevalence and association with increased risk of stroke, heart failure, and death Several genetic loci responsible for familial AF have been identified, such as potassium- and sodium-channel genes PITX2 encoding a transcription factor that influences heart development, especially the pulmonary veins Since the 4q25 haplotype block is located about 100–200 thousand base pairs away from known genes, its functional significance is not known. The closest gene is The aim of our study was (a) to determine the association between variants on chromosome 4q25, 16q22 and 1q21 and AF in a highly selected group of Polish patients that underwent pulmonary vein isolation, and (b) to explore the putative influence of those variants on left atrium diameter (antero-posterior), pulmonary vein diameter and presence of patent foramen ovale (PFO), as well as several clinical parameters such as paroxysmal-persistent AF, coexistence of atrial flutter (AFL), AF burden (number of episodes of AF), age of onset of AF, and frequency of lone AF.We performed a case-control study.The study comprised 410 consecutive patients with AF  that underwent pulmonary vein isolation in the years 2006–2009. Inclusion criteria: symptomatic AF without reversible cause, unsuccessful treatment with at least one antiarrhythmic drug (group Ic or III), age below 70 years. Exclusion criteria: hyperthyroidism, significant mitral stenosis/insufficiency, left atrial dimension over 5.5 cm, severe disease with life expectancy below 1 year. Before each procedure patients underwent either transesophageal echocardiography or computer tomography of the left atrium.The study was approved by the Bioethics Committee of the Medical University of Warsaw and all patients gave written informed consent.The following clinical parameters were recorded: presence of hypertension, coronary disease, heart failure, diabetes, history of hyperthyroidism. Patients were also asked about the year of the onset of AF and mean number of episodes of AF per month (within the last 6 months). Presence of concomitant atrial flutter (AFL) was defined as at least one episode of AFL with a typical ECG pattern. Definitions of paroxysmal, persistent and lone AF were according to the European guidelines DNA samples from controls were obtained from a bank of samples collected during a recent Polish population-wide health survey WOBASZ  . Assays were performed according to the manufacturer's instructions using a 7500 Real-Time PCR System (Applied Biosystems).Continuous variables are presented as mean ±SD (standard deviation) or median (1–3 quartile), depending on variable distribution. Categorical variables are presented as frequencies. The Chi2 or Fisher exact tests were used to test deviations of the genotype distribution from Hardy–Weinberg equilibrium and to compare allele and genotype frequencies between groups. Effects of genotypes on continuous parameters were analyzed by one-way ANOVA or relevant non-parametric tests . Comparison of diameters of pulmonary veins in the recessive model, due to significant deviations from normal distribution, was performed with Mann-Whitney U test. Multivariate logistic regression was performed to assess independent significance of all 4q25 polymorphisms. Haplotype analysis was performed with PLINK software Sample size calculation (post-hoc) was performed using top 4q25 polymorphisms (rs2200733 and rs10033464). Based on previous results we assumed polymorphic allele frequency of rs10033464 equal to 0.08 for controls and 0.12 for cases, and for rs2200733 0.11 and 0.17, respectively The characteristics of the patients and controls is shown in 2< = 0.1) except for rs3853445–rs6838973 . The strongest effect was conferred by the TGAC haplotype which had a frequency of 0.257 among cases vs. 0.074 among controls, conferred a relatively high risk for AF (OR = 4.33) and was highly significantly associated with the disease . The mean number of AF episodes (95% CI) was 7.3 (5.4–9.1), 8.8 (6.8–10.8) and 12.9 (8.8–16.3) for patients with the CC, CT and TT genotypes, respectively. The haplotype with the strongest link with AF . Age or sex did not affect significantly the pulmonary vein diameter. The correlation was significant for the left inferior pulmonary vein whereas there was a trend for the left and right superior and no effect for the right inferior pulmonary vein . None ofWe did not see any correlation of the polymorphsims tested with concomitant diseases  or with the frequency of lone AF, persistent AF, AFL coexistence, age of diagnosis of AF, or left atrial diameter (data not shown).−27) exceeded the threshold used for genome-wide studies. We also provide the first confirmation of the results recently reported by Lubitz et al. Our results provide a strong confirmation of the association between AF and 4q25, 16q22 and 1q21 variants, in particular rs2200733 for which the statistical significance of the observed association . Although only about 30% of our group had lone AF, the frequency of rs13376333 was comparable to that in a population with lone AF We observed that patients with the T allele of rs2200733 had a larger diameter of pulmonary veins, in particular when the genetic effect was modeled as recessive. That could be related to the earlier observation that patients with the T allele have more recurrences after catheter ablation The mechanisms of the effect of the 4q25 genetic variants on AF is not clear. The nearest gene is PITX2 (Paired-like homeodomain transcription factor 2), important for determining the left–right asymmetry and for the differentiation of the left atrium The main limitation of the study is connected with the high number of hypotheses tested in the exploration of novel genotype –phenotype correlations. Therefore all the observations regarding new associations/correlations should be verified in adequately powered dedicated studies.Polish patients qualified for catheter ablation due to AF have a significantly higher frequency of 4q25 , 16q22 and 1q21 variants than the control group. The T allele of rs2200733 seems to favour larger pulmonary veins and a higher number of episodes of AF but it should be verified in future studies.


Overexpression of phosphatase of regenerating liver 3 (PRL-3) has been implicated in gastric cancer (GC) metastasis. Epidemiological studies have evaluated the relationship between PRL-3 expression and prognosis in GC. However, results still remains controversial. In this study, a meta-analysis was performed to evaluate the association of PRL-3 expression with overall survival (OS) and clinicopathological characteristics.Literature databases were searched to identify eligible studies dated until April 2013. Summary hazard ratios (HRs) or odds ratios (ORs) with 95% confidence interval (95% CI) were calculated to estimate the association.P<0.001). Results showed that PRL-3 overexpression was significantly associated with OS, indicating that it may be a biomarker for poor prognosis of GC. Both subgroup and sensitivity analyses further identified the prognostic role of PRL-3 expression in GC patients. Moreover, PRL-3 overexpression was significantly associated with tumor stage , depth of invasion , vascular invasion , lymphatic invasion , and lymph node metastasis . However, when age, sex, tumor size, and tumor differentiation were considered, no obvious association was observed.A total of 1380 GC patients from six studies were included in the meta-analysis. Overall, the combined HR estimate for OS in a random-effect model was 1.89 (95% CI = 1.38–2.60; This meta-analysis reveals significant association of PRL-3 overexpression with OS and some clinicopathological features in GC. PRL-3 may be a predicative factor of poor prognosis and aggressive tumor behavior in GC patients. The incidence and mortality of gastric cancer (GC) have dramatically decreased over the past few decades in many regions. However, this disease remains the second most common malignancy worldwide, with an estimated 989 600 new cases in 2008 Considerable effort has been exerted to identify prognostic biomarkers in GC patients. Although some genes  have been investigated in recent studies Protein tyrosine phosphatases (PTPs) are key regulatory enzymes in signal transduction pathways that are implicated in the tumorigenesis and metastasis of human cancers Several studies have attempted to determine whether PRL-3 expression may be a prognostic factor for survival in GC patients. However, the results of these studies are controversial or inconclusive because of their limited sample size or genuine heterogeneity. Accordingly, this study aimed to review all available studies that investigated the relationship between PRL-3 overexpression and its clinical outcome in GC patients. A meta-analysis was conducted to more precisely estimate the prognostic significance of PRL-3 expression.The PubMed, ISI Web of Science, and Embase databases were searched to identify studies that assessed PRL-3 as a prognostic factor for survival in GC patients. The search ended in April 21, 2013, and no lower date limit was used. The search terms were “PRL-3,” “PRL3,” “PTP4A3,” “phosphatase of regenerating liver 3”; or “protein tyrosine phosphatase type IVA member 3” and “gastric tumors,” “gastric cancer,” “gastric carcinoma,” “gastric neoplasms,” “stomach cancer,” “stomachic cancer,” “stomachal cancer”; or “GC” and “survival,” “prognostic”; or “prognosis.” No language restriction was imposed. All references cited in the included studies were also reviewed to identify additional published articles not indexed in the common database.The studies included in this meta-analysis are either retrospective or prospective cohort studies that evaluated the association between PRL-3 expression and overall survival . Studies considered ineligible for the meta-analysis were as follows: reviews, conference abstracts, editorials, or letters; and articles with insufficient published data in a full-text paper for determining an estimate of hazard ratio (HR) and 95% confidence interval (CI). In case of multiple publications from the same institution with identical or overlapping patient cohorts, only the largest study was included to avoid duplication of information.P-value of the log-rank statistic were retrieved to permit an approximate calculation of the HR estimate and its variance. If the study did not provide a HR but reported the data in the form of the survival curve, survival rates at certain specified times were extracted from them for the reconstruction of the HR estimate and its variance, with the assumption that the rate of patients censored was constant during the follow-up.Two authors (Hu L.R. and Luo H.Q.) independently extracted data from eligible studies, and disagreements were resolved through consensus to all items. Standardized abstraction sheets were used to record data from individual studies. Data retrieved from the articles included the following: first author, year of publication, country of origin, ethnicity, number of patients analyzed, follow-up months, analysis method, blinding of PRL-3 measurements, cut-off value, number of high/low PRL-3 expression, HR estimation, and quality scores. For each study, HR was estimated using an approach reported by Parmar et al Quality assessment for the studies in this meta-analysis was performed using the Newcastle Ottawa scale (NOS) recommended by the Cochrane Non-Randomized Studies Methods Working Group STATA version 11.0  was used for all statistical analyses. For the pooled analysis of the correlation between PRL-3 overexpression and clinicopathological features , odds ratios (ORs) with their corresponding 95% CI were combined to estimate the effect. The combined HR with 95% CI was used to calculate and assess the strength of the association of PRL-3 expression. An observed HR>1 indicated a poor prognosis for the group with PRL-3 overexpression and would be considered to be statistically significant if the 95% CI did not overlap 1.Q statistic P<0.10. Heterogeneity was quantified by the I2 metric, which is independent of the number of studies used in the meta-analysis . The pooled HR estimation of each study was calculated using a random-effects model (DerSimonian and Laird method) when P<0.10; otherwise, a fixed-effect model was used (Mantel–Haenszel method) Heterogeneity assumption was examined by the chi-squared test based on the P<0.10.To validate the credibility of outcomes in this meta-analysis, sensitivity analysis was performed by sequential omission of each individual study using the “metaninf” STATA command. Potential publication bias was evaluated through Begg’s and Egger’s Asymmetry tests P<0.001, fixed effect), depth of invasion , vascular invasion , lymphatic invasion , and lymph node metastasis . These findings suggested that PRL-3 overexpression was obviously associated with tumor stage, extent of invasion, and lymph node metastasis. However, no association existed between PRL-3 and other clinicopathological parameters such as age , sex , tumor size , and tumor differentiation .The associations of PRL-3 with clinicopathological characteristics were illustrated in Z = 3.95; P<0.001, random effect), although a significant degree of heterogeneity  was present. Further analysis was performed on data stratified by variance analysis to determine possible factors that may have influenced the results. Results showed that poor prognosis was found in GC patients with PRL-3 overexpression under multivariate analyses  and univariate analyses . When subgrouped by ethnicity, unfavorable survival results were observed in patients from Asian populations  and Caucasian populations . After exclusion of the study without blinded evaluation Z = 3.54; P<0.001, random effect); after omission of the study Z = 3.57; P<0.001, random effect). Furthermore, a prognostic effect on survival was also observed in the three largest studies We also carried out a meta-analysis on the association of PRL-3 overexpression in GC patients with OS. The pooled HRs along with their 95% CI were presented in detail in In the sensitivity analysis, the influence of each study on the pooled HR was examined by repeating the meta-analysis while omitting each study one at a time. Z = 0.00; P = 1.000) or the Egger’s tests . The shapes of the funnel plots also showed that the included studies did not have apparent asymmetry, thereby indicating that our results were statistically robust.Publication bias was analyzed in the included literature involving the overall HR estimation of OS. No obvious publication bias was detected in either Begg’s test . Thus, the results are encouraging and may provide further basis for the development of new markers for GC prognosis and of PRL-3 inhibitors for individualized therapy.However, the results should be interpreted very cautiously. In this review, the test for heterogeneity of the included studies was significant. Although we used subgroup analyses by variance analysis, ethnicity, PRL-3 measurements, blinded evaluation, and the number of patients during pooling data, all stratified analyses did not identify the source of heterogeneity. Moreover, sensitivity analysis did not help clarify the source of heterogeneity in this study. Therefore, multidimensional network meta-analysis models for published survival curves can be established to explain systematic heterogeneity across studies and to reduce inconsistencies Although the present meta-analysis had some advantages over other individual studies, a few limitations were also inherent. First was our inability to explore the potential effect of confounding factors, such as tumor location and different treatment regimens, because of insufficient information in the included studies. Second, the studies included in the meta-analysis were from different sources of PRL-3 antibody and dilutions of the antibodies, indicating a possibility that antibody factors can confound the results. Third, differences in the cutoff definition of PRL-3 overexpression and the experimental processes may partly influence the significance of the clinicopathological outcome in survival analyses and partially account for the inter-study heterogeneity. The fourth and last limitation is related to the approach of the HRs and 95% CI estimations. In the meta-analysis, HRs and 95% CI were directly extracted from original data in three included studies. For all other studies, HR had to be extrapolated from the survival curve. Thus, the estimated HR may be less reliable than when directly obtained from published statistics We hereby make the following recommendations to future studies: 1) a large series of consecutive patients from a single cohort, 2) sufficient long-term follow-up, 3) usage of monoclonal instead of polyclonal antibody directed against PRL-3 for immunostaining, 4) uniform standard for assessment overexpression, 5) complete description of the clinical characteristics of a study population, 6) presentation of results as survival curves and as a multivariate Cox proportional hazard model, and 7) complete description of survival events to time. Moreover, further studies should include more homogeneous populations and be prospective.In summary, this meta-analysis revealed that PRL-3 overexpression was significantly associated with poor OS and clinicopathological features in GC. PRL-3 expression may be a predicative factor of poor prognosis and aggressive tumor behavior in GC patients.Figure S1The forest plot for the overall association between PRL-3 overexpression and age in GC patients. The contribution of each study to the meta-analysis (its weight) is represented by the area of a box, the center of which represents the size of the OR estimated from that study. The 95% CI for the OR (extending lines) from each study is also shown. The pooled OR is shown in the middle of a diamond, the left and right extremes of which represent the corresponding CI.(TIF)Click here for additional data file.Figure S2The forest plot for the overall association between PRL-3 overexpression and sex of GC patients. The contribution of each study to the meta-analysis (its weight) is represented by the area of a box, the center of which represents the size of the OR estimated from that study. The 95% CI for the OR (extending lines) from each study is also shown. The pooled OR is shown in the middle of a diamond, the left and right extremes of which represent the corresponding CI.(TIF)Click here for additional data file.Figure S3The forest plot for the overall association between PRL-3 overexpression and tumor size of GC patients. The contribution of each study to the meta-analysis (its weight) is represented by the area of a box, the center of which represents the size of the OR estimated from that study. The 95% CI for the OR (extending lines) from each study is also shown. The pooled OR is shown in the middle of a diamond, the left and right extremes of which represent the corresponding CI.(TIF)Click here for additional data file.Figure S4The forest plot for the overall association between PRL-3 overexpression and tumor differentiation of GC patients. The contribution of each study to the meta-analysis (its weight) is represented by the area of a box, the center of which represents the size of the OR estimated from that study. The 95% CI for the OR (extending lines) from each study is also shown. The pooled OR is shown in the middle of a diamond, the left and right extremes of which represent the corresponding CI.(TIF)Click here for additional data file.Figure S5The forest plot for the overall association between PRL-3 overexpression and tumor stage of GC patients. The contribution of each study to the meta-analysis (its weight) is represented by the area of a box, the center of which represents the size of the OR estimated from that study. The 95% CI for the OR (extending lines) from each study is also shown. The pooled OR is shown in the middle of a diamond, the left and right extremes of which represent the corresponding CI.(TIF)Click here for additional data file.Figure S6The forest plot for the overall association between PRL-3 overexpression and depth of invasion of GC patients. The contribution of each study to the meta-analysis (its weight) is represented by the area of a box, the center of which represents the size of the OR estimated from that study. The 95% CI for the OR (extending lines) from each study is also shown. The pooled OR is shown in the middle of a diamond, the left and right extremes of which represent the corresponding CI.(TIF)Click here for additional data file.Figure S7The forest plot for the overall association between PRL-3 overexpression and vascular invasion of GC patients. The contribution of each study to the meta-analysis (its weight) is represented by the area of a box, the center of which represents the size of the OR estimated from that study. The 95% CI for the OR (extending lines) from each study is also shown. The pooled OR is shown in the middle of a diamond, the left and right extremes of which represent the corresponding CI.(TIF)Click here for additional data file.Figure S8The forest plot for the overall association between PRL-3 overexpression and lymphatic invasion of GC patients. The contribution of each study to the meta-analysis (its weight) is represented by the area of a box, the center of which represents the size of the OR estimated from that study. The 95% CI for the OR (extending lines) from each study is also shown. The pooled OR is shown in the middle of a diamond, the left and right extremes of which represent the corresponding CI.(TIF)Click here for additional data file.Figure S9The forest plot for the overall association between PRL-3 overexpression and lymph node metastasis of GC patients. The contribution of each study to the meta-analysis (its weight) is represented by the area of a box, the center of which represents the size of the OR estimated from that study. The 95% CI for the OR (extending lines) from each study is also shown. The pooled OR is shown in the middle of a diamond, the left and right extremes of which represent the corresponding CI.(TIF)Click here for additional data file.Checklist S1Prisma checklist.(DOC)Click here for additional data file.


To explore whether risk factors for neurophysiologically confirmed carpal tunnel syndrome (CTS) differ from those for sensory symptoms with normal median nerve conduction, and to test the validity and practical utility of a proposed definition for impaired median nerve conduction, we carried out a case–control study of patients referred for investigation of suspected CTS.We compared 475 patients with neurophysiological abnormality (NP+ve) according to the definition, 409 patients investigated for CTS but classed as negative on neurophysiological testing (NP-ve), and 799 controls. Exposures to risk factors were ascertained by self-administered questionnaire. Odds ratios (ORs) and 95% confidence intervals (95% CIs) were estimated by logistic regression.NP+ve disease was associated with obesity, use of vibratory tools, repetitive movement of the wrist or fingers, poor mental health and workplace psychosocial stressors. NP-ve illness was also related to poor mental health and occupational psychosocial stressors, but differed from NP+ve disease in showing associations also with prolonged use of computer keyboards and tendency to somatise, and no relation to obesity. In direct comparison of NP+ve and NP-ve patients (the latter being taken as the reference category), the most notable differences were for obesity , somatising tendency , diabetes  and work with vibratory tools .When viewed in the context of earlier research, our findings suggest that obesity, diabetes, use of hand-held vibratory tools, and repeated forceful movements of the wrist and hand are causes of impaired median nerve function. In addition, sensory symptoms in the hand, whether from identifiable pathology or non-specific in origin, may be rendered more prominent and distressing by hand activity, low mood, tendency to somatise, and psychosocial stressors at work. These differences in associations with risk factors support the validity of our definition of impaired median nerve conduction. In western countries, upper limb disorders are a common cause of morbidity and disability among people of working age-3. In soPrevention of upper limb disorders requires the identification of modifiable causes, and to this end, diagnostic classifications have been developed with the aim of distinguishing categories of complaint which might differ importantly in their aetiology-6. In a To explore whether this applies in relation to carpal tunnel syndrome (CTS), we carried out a prospective case–control study of patients referred for neurophysiological investigation because of suspected CTS, in which we distinguished case groups with and without abnormal sensory nerve conduction in the median nerve. We compared associations with various known and suspected risk factors for CTS and/or distal arm symptoms, our hypothesis being that physical risk factors would be particularly important in the development of nerve compression, whereas psychosocial risk factors would have greater impact on non-specific symptoms. We defined abnormal sensory nerve conduction according to criteria that had been developed in an earlier analysis of the inter-relation of symptoms, signs and nerve conduction velocities. Our anaThe study population comprised adults aged 20–64 years who were resident in the catchment area served by both the neurophysiology and accident and emergency services at Southampton General Hospital. Ethical approval for the study was provided by the Southampton and South West Hampshire NHS Research Ethics Committee.All members of the study population who attended the neurophysiology service between January 2007 and September 2009 for investigation of suspected CTS were sent a letter inviting them to answer a self-administered questionnaire and then bring it with them when they visited the hospital. In a few cases where patients failed to complete part or all of the questionnaire before coming to hospital, they were asked to do so in the clinic or to return the questionnaire later by post. The service was the only provider of nerve conduction studies for almost all of a local population of some 440,000 people, referrals coming mainly from general practitioners and orthopaedic surgeons.Nerve conduction studies were carried out according to the normal practice of the service, by a physician or clinical physiologist trained in neurophysiology, using a Nicolet machine. Among other things, measurements were made of orthodromic sensory nerve conduction (SNC) from the index, middle and little fingers to the wrist, surface recordings being made over the median and ulnar nerves proximal to the distal wrist crease. With the patient’s permission, the findings were subsequently abstracted from the clinical record.NP+ve cases were defined as those with at least one hand in which there had been numbness, tingling or pain in the past four weeks, and in which SNC in the median nerve was abnormal. SNC in the median nerve was considered abnormal if no signal was detectable from the index finger or if the difference in SNC velocity between the little and index fingers was > 8 m/s. This cut-point was based on an earlier comparison of the distribution of nerve conduction measurements between hands with symptoms and signs most suggestive of CTS and those with no symptoms or signs[Controls were selected according to a standardised algorithm from members of the study population who attended the Accident and Emergency Department at Southampton General Hospital during the same study period, and underwent radiological examination as part of their management. They were group matched to the cases by sex and age. Controls were sent the same questionnaire as the cases, and asked to return it to the study team by post.Our original aim was to recruit a total of at least 1000 cases and 1000 controls, which was calculated to give more than 80% power to detect a relative risk of 1.8 in a direct comparison between NP+ve and NP-ve cases for a risk factor with 10% prevalence in the latter group.Among other things, the questionnaire asked about demographic variables; history of symptoms in the hand and arm and associated disability for everyday tasks; height and weight; ethnic origin; smoking habits; previous diagnosis of diabetes, rheumatoid arthritis or other arthritis; mental health; somatising tendency; and current or most recent occupation.2. Mental health was evaluated through the relevant domain from the Short Form-36 (SF-36) questionnaire[The information on height and weight was used to derive body mass index (BMI) in kg/mionnaire, and scoionnaire, and wasStatistical analysis was carried out with Stata version 11.1 software. We first excluded: subjects who fell outside the specified age range ; cases who reported previous carpal tunnel surgery, who had not experienced any sensory symptoms in the hand during the past month or who had no satisfactory nerve conduction measurements in either hand; and controls with a previous diagnosis of CTS.We then sub-divided the remaining cases according to whether or not they were neurophysiologically confirmed (NP+ve or NP-ve), and derived simple descriptive statistics for the controls and the two case groups.Finally, we used logistic regression to explore risk factors for the two categories of case. All associations were adjusted for the group matching variables (sex and age) and for ethnic origin, and were summarised by odds ratios (ORs) and associated 95% confidence intervals (95% CIs). We first explored associations for each risk factor individually, and then used forward stepwise regression to construct a model giving mutually adjusted risk estimates for the most important risk factors. The criterion for adding a variable to the model was a p-value of < 0.2 for the reduction in deviance. Finally, we carried out similar stepwise regression to compare NP+ve cases directly with NP-ve cases, the latter being taken as the reference group.Over the course of the study, we approached 1248 potentially eligible cases, among whom 911 (73%) completed questionnaires  completed questionnaires, but 100 were excluded because they were outside the required age range (4), had a previous diagnosis of CTS  or missing information on history of CTS (1). Among the remaining 799 controls who were analysed, there was a broad mix of diagnoses, the most frequent categories of radiological investigation being ankle/foot (27%), wrist/hand (26%), chest (16%), other lower limb (13%) and other upper limb (12%).Table Table Table Table Table Direct comparison of the two case groups  was short of ideal, although not atypical of what can be achieved nowadays using postal questionnaires in the UK. It is possible that the much lower prevalence of non-white patients among the controls as compared with the two case groups was an artefact of the method by which controls were selected, people from some ethnic groups being under-represented among patients attending Accident and Emergency. For this reason, all risk estimates were adjusted for ethnicity. Beyond this, however, we have no reason to suspect that our control group was importantly unrepresentative of the study population in relation to the exposures under study. Furthermore, the low response rate in the control group would not impact on the direct comparisons that were made between the two case groups. The response rate among potentially eligible cases was higher (73%), and as cases were not aware of their neurophysiological findings at the time when they agreed to take part in the study, it is unlikely that the incomplete response from cases would have caused important bias.Although patients with a previous medical diagnosis of CTS were excluded from the control group, it is likely that the controls included some patients with sensory symptoms in the hand which had never led to medical consultation, or if they had, had not been diagnosed as CTS. To the extent that this occurred, it may have diminished differences between cases and controls, but it should not have spuriously inflated associations. Moreover, it would not have affected the direct comparisons between NP+v and NP-ve cases.Information about exposure to risk factors was ascertained by questionnaire, and participants’ recall may not always have been accurate. If errors were non-differential (i.e. similar in cases and controls), the effect will have been to obscure associations with illness. However, it is possible that for some exposures, recall differed systematically between cases and controls. For example, the presence of hand symptoms might make people more aware of occupational activities involving use of the hands, and therefore more likely to report such activities. Again, however, such bias could not account for the differences that were observed between the two case groups.A further limitation of the study method was the ascertainment of exposures at the time when patients presented for neurophysiological investigation, and not when their symptoms first began, which in some cases was months earlier. It is possible, for example, that some cases had changed their occupation in the interval since their illness first developed. However, when the analyses in Table Despite the potential for errors in the ascertainment of exposures, we found clear positive associations of neurophysiologically confirmed CTS with higher BMI, occupational use of vibratory tools and repetitive work with the wrist or fingers. These findings accord with the balance of evidence in the published literature-22, whicMore controversial is the relation of CTS to smoking. In our study, risk of neurophysiologically confirmed CTS was lower in current smokers . One earlier case–control study also found a significant inverse association with smoking, but in Previous research on the relation of CTS to mental health and psychosocial aspects of work has also been conflicting. A positive association with psychological distress was reported in a longitudinal study at a French footwear factory; with haMost notable among our findings were the differential associations with obesity (significantly more common in NP+ve cases) and somatising tendency (significantly more frequent in NP-ve cases). In addition, diabetes and work with vibratory tools both tended to be more prevalent in the NP+ve cases . There have been few attempts previously to compare risk factors in patients with suspected CTS according to neurophysiological findings, although in one large case series, BMI was a significant predictor of definite neurophysiological abnormality in patients under the age of 63 years. In addiThe pattern of associations that we observed gives some support to our prior hypothesis that NP+ve illness would be more strongly associated with physical risk factors, and NP-ve illness with psychological risk factors. However, the difference was not completely clear-cut, and based on our findings, the hypothesis can be refined.We propose that the physiological abnormalities associated with obesity and diabetes, and the physical stresses to tissues from use of hand-held vibratory tools and repeated forceful movements of the wrist and hand, all cause impaired function of the median nerve, which in turn can give rise to sensory symptoms in the hand. At the same time, physical activity of the hand and arm, even if insufficient to injure tissues, may aggravate sensory symptoms and/or make them more noticeable, whatever their pathogenesis. Similarly, low mood, tendency to somatise, and psychosocial stressors at work may all cause sensory symptoms, of whatever origin, to be more distressing, thereby increasing the likelihood of medical consultation and that the symptoms will be reported when those affected are questioned. However, these psychological risk factors may be relatively less important where there is a clear pathological origin of symptoms.Further research is needed to test this theory, which could have important implications for preventive strategies. For example, if occupational activities such as prolonged use of computer keyboards act only to focus attention on symptoms, and do not injure tissues, it may be counter-productive to portray them as important health hazards requiring careful risk assessment and control, as is currently implied by legislation in the European Union. Doing sOur findings are also an encouragement to refinement of case definitions for other upper limb disorders where this can be done using criteria that are independent of symptoms and subjectively influenced physical signs such as tenderness and limitation of active movement. Moreover, they support the validity and utility of our proposed definition for abnormal median nerve conduction.The authors declare that they have no competing interests.DC and KTP conceived the study and oversaw its conduct. RVdS and CC contributed to the study design. CL and ECH carried out the data collection and helped prepare the data for analysis. GN carried out the statistical analysis. DC wrote the first draft of the manuscript. All of the authors contributed to revision and finalisation of the manuscript. All authors read and approved the final manuscript.The pre-publication history for this paper can be accessed here:http://www.biomedcentral.com/1471-2474/14/240/prepub