Genotoxicity studies in Ecuador have been carried out during the past two decades. The focuses of the research were mainly the area of environmental issues, where the populations have been accidentally exposed to contaminants and the area of occupational exposure of individuals at the workplace. This paper includes studies carried out in the population of the Amazon region, a zone known for its rich biodiversity as well as for the ecological damage caused by oil spills and chemical sprayings whose consequences continue to be controversial. Additionally, we show the results of studies comprised of individuals occupationally exposed to toxic agents in two very different settings: flower plantation workers exposed to pesticide mixtures and X-ray exposure of hospital workers. The results from these studies confirm that genotoxicity studies can help evaluate current conditions and prevent further damage in the populations exposed to contaminants. As such, they are evidence of the need for biomonitoring employers at risk, stricter law enforcement regarding the use of pesticides, and increasingly conscientious oil extraction activities. Genotoxicity is a collective term that refers to any process that affects the structural integrity of DNA . This muGSTP1 Ile105Val, GPX-1 Pro198Leu, and XRCC1 Arg399Gln) that have been previously associated to the alteration of antioxidant activity, DNA detoxicating processes, and protective functions [GSTP1 gene encodes for glutathione S-transferase pi, an enzyme that is involved in the protection against exogenous and endogenous oxidative damage [GSTP1 Ile105Val polymorphism has been associated to higher levels of DNA damage in pesticide-exposed populations [GSTP1 Val/Val genotype associated with enzyme dysfunction was observed in the exposed individuals. On the other hand, the GPX-1 gene encodes for one of the most important detoxifying enzymes: gluthatione peroxidase. This enzyme protects mammalian cells, especially human erythrocytes, against oxidative damage [GPX-1 Pro198Leu polymorphism has been exhaustively studied in relation to cancer, the study in Ecuador identified the prevalence of the Leu allele of the GPX-1 gene in glyphosate-exposed individuals that suggests a higher risk of DNA damage and increased sensitivity to herbicides. The third gene that was part of the study, XRCC1, is involved in the mechanisms of DNA single-strand breaks (SSBs) and base-excision repair (BER) that could modify the individual susceptibility to the genotoxic effect of xenobiotics [ XRCC1 gene genotypes and an increased risk of DNA damage due to pesticide exposure, similar results were not found for the Ecuadorian population studied [The northeastern Ecuadorian border underwent the aerial spraying of an herbicide mix during the period of 2002–2007 and was supported by the Colombian government . The Rouunctions –33. The e damage . As a mee damage , 36. Speulations . In the e damage . Studiese damage . Althougobiotics , 41. Alt studied . Aside f studied .A previous study took place two years before the aforementioned study at the Ecuadorian border. It involved individuals living within 200 m to 3 Km from the areas under continuous and sporadic spraying , 43. TheDespite the known risks of the use of some pesticides due to their potential health consequences , many ofCYP1A1 gene, a gene that has been extensively studied in relation to occupationally exposure to pesticides [CYP1A1 MspI and Ile/Val gene polymorphisms. Though CA and comet assay showed interesting results, the gene was not linked to pesticide exposure in the studied population, as opposed to other populations [Pesticide genotoxicity was also studied in individuals working as pesticide applicators in the zone of Cayambe, northeast from Quito. The workers were exposed to 46 pesticides of different degrees of toxicity and at different concentrations and mixtures during work at the plantation . The metsticides . Becausesticides –61. In aulations , 63.As an important element of the agricultural production, pesticides have become a necessary tool for crop management in developing countries , 65. NonCYP1A1  and MSH2 (gIVS12-6T>C), both related to the development of cancer [CYP1A1 gene polymorphisms were not related to either group, as it has been reported previously in the Caucasian population [MSH2 gene polymorphism between groups which suggests a higher susceptibility to DNA damage in the exposed group [The Ecuadorian Amazon is one of the ecologically richest regions in the world and it is also sparsely populated. The oil extraction activity in Ecuador began in 1972, it became economically fundamental immediately and continues to be the principal source of national income . Unfortuf cancer , 89, 90.pulation . Howevered group . Taking Environmental mutagens can be broadly classified as radiation and chemicals . IonizinDrosophila over 70 years ago, the established idea has been that the genotoxic effects of ionizing radiation, such as mutations and carcinogenesis, are caused by the direct damage of the cell nucleus [Ever since X-rays were shown to induce mutation in  nucleus , 95. Dia nucleus . Because nucleus .Ionizing radiation is capable of acting on the living cell causing several effects that result from the excitation of atoms and molecules that ultimately cause structural changes. At a molecular level, DNA is possibly affected by water ionization that forms free radicals and promotes the oxidation of several compounds and hydrogen oxide . Even smA second study focused on telomeric associations in individuals exposed both to X-rays and smoke in order to determine the existence of these associations as chromosomal markers of exposure to these carcinogenic agents. The phenomenon of telomeric association is an intermediate step in the progression towards chromosomal instability that also comprises a risk of developing cancer , 109. CyIn another study, the inclusion of gaps as chromosomal aberration was investigated. Gaps are defined as the unstained regions of a chromosome that contain zones of lesser width than that of a chromatid , 116. A Cytogenetic findings are of great importance because they are associated with the mechanisms of carcinogenesis. The interaction with physical agents, such as ionizing radiation, produces a variety of primary lesions  whose pr


NFKB1 encoding NF-κB1 and NFKBIA encoding IκBα with the susceptibility of developing HCC and clinicopathological characteristics of the tumors.Constitutive activation of nuclear factor (NF)-κB is frequently observed in hepatocellular carcinoma (HCC). The current study examined associations of polymorphisms within promoter regions of NFKB1 and NFKBIA were analyzed by a real-time polymerase chain reaction (PCR) in 135 HCC patients and 520 healthy controls. The genotypic frequency of the NFKB1 -94 Ins polymorphism in HCC patients was significantly higher than that of the controls (adjusted odds ratio (AOR) = 2.23; 95% confidence interval (CI) 1.32∼3.77). No statistical significance was observed for the distribution frequency of the NFKBIA −-519 C/T, -826 C/T, or -881 A/G genotype and haplotype polymorphisms between HCC patients and controls. Furthermore, female HCC patients carrying the NFKB1 -94 Ins polymorphism were associated with lower clinical stages and smaller tumor sizes.Genetic polymorphisms of NFKB1 -94 Ins promoter polymorphism increased the risk of HCC, and may be applied as a predictive factor for the clinical stage and tumor size in female HCC patients.Our results indicate that the  Hepatocellular carcinoma (HCC) is the most common primary liver cancer and the second leading cause of cancer-related deaths in Taiwan; thus, HCC is one of the most important cancers worthy of our concern Nuclear factor (NF)-κB is an important transcription factor for maintaining normal immune system function; inadequate NF-κB activation can mediate inflammation and tumorigenesis NFKB1 or its inhibitory protein, IκB, can potentially regulate NF-κB signaling and contribute to the carcinogenesis of HCC. Among the five members of the NF-κB family  in mammalian cells, the major form of NF-κB is a heterodimer of the p50 and p65/Rel A subunits NFKB1 gene located on chromosome 4q23–24, has a common -94 Del/Ins polymorphism in the promoter region. The promoter sequence containing the -94 Ins polymorphism increases NFKB1 messenger (m)RNA expression and is associated with susceptibility to ulcerative colitis NFKBIA gene comprises a relatively large number of polymorphisms. NFKBIA -519 C/T, -826 C/T, and -881 A/G polymorphisms are respectively located at putative binding sites for transcription factors CCAAT/enhancer binding protein, GATA binding protein 2, and retinoic acid-related orphan receptor α, NFKB1 and NFKBIA genes to be associated with cancer risk and severity in sporadic colorectal cancer and oral cancer, NFKB1 and NFKBIA gene promoter polymorphisms to the occurrence of HCC in Taiwanese and evaluated their relevance by correlating them with tumor clinicopathological characteristics.Functional nucleotide polymorphisms in either The present hospital-based case-control study recruited 135 HCC patients in 2007∼2010 at Chung Shan Medical University Hospital, Taichung, Taiwan. A diagnosis of HCC was based on characteristic criteria of national guidelines for HCC, such as liver tumor tissue diagnosed by histology or cytology irrespective of the α-fetoprotein (AFP) titer where imaging data, either computed tomography or magnetic resonance imaging, showed one of following: (1) one or more liver masses of ≥2 cm in diameter; (2) imaging data with early enhancement and a high level of AFP of ≥400 ng/mL; and (3) imaging data with early arterial phase-contrast enhancement plus early venous phase-contrast washout. During the same study period, 520 race- and ethnic group-matched individuals were enrolled as the controls who entered the physical examination at the same hospital. These control groups had neither self reported history of cancer of any sites. Personal information and characteristics collected from the study subjects using interviewer-administered questionnaires contained questions involving demographic characteristics and the status of cigarette smoking and alcohol drinking. Nonsmokers were defined as individuals who had never smoked or had smoked for less than one year, and others were defined as smokers. Non-drinkers were defined as those who had never drank or had drank less than once per week and/or for less than one year, and others were defined as alcohol drinkers.American Joint Committee on Cancer (AJCC) Staging Manual (7th ed.) HCC patients were clinically staged at the time of diagnosis according to the TNM staging system of the Genomic DNA was extracted using QIAamp DNA blood mini kits  following the manufacturer’s instructions. We dissolved DNA in TE buffer (10 mM Tris at pH 7.8 and 1 mM EDTA) and then quantified it by measuring the optical density at 260 nm. The final preparation was stored at −20°C and used to create templates for the polymerase chain reaction (PCR).NFKB1 -94, NFKBIA -519, NFKBIA -826, and NFKBIA -881 gene polymorphisms were assessed with the ABI StepOne™ Real-Time PCR System  and analyzed using SDS v3.0 software (Applied Biosystems), with the TaqMan assay Allelic discrimination of the p values of <0.05. Hardy-Weinberg equilibrium (HWE) was assessed using a goodness-of-fit Χ2-test for biallelic markers. The Mann-Whitney U-test and Fisher’s exact test were used to compare differences in demographic characteristic distributions between the healthy control group and HCC patients. The adjusted odds ratios (AORs) and 95% confidence intervals (CIs) of the association of genotype frequencies with risk and clinicopathological characteristics were estimated using multiple logistic regression models after controlling for other covariates. We analyzed all data with Statistical Analytic System  software  for Windows.Differences between groups were considered significant for In this case-control study, the statistical analysis of demographic characteristics of HCC patients showed significant differences in the distribution of ages and genders compared to the controls, but not in alcohol or tobacco consumption . To reduNFKB1 -94 Del/Ins and NFKBIA -519 C/T, -826 C/T, and -881 A/G between patients and controls are presented in p>0.05). After adjusting for other confounders, a significantly increased risk was found for HCC patients carrying the NFKB1 -94 Ins polymorphism compared to those homozygous for the -94 Del polymorphism. Compared to corresponding wild-type (WT) homozygotes of the control group, the risk for HCC was 1.85-fold (95% CI: 1.04∼3.27) for -94 Del/Ins, 3.52-fold (95% CI: 1.75∼7.10) for -94 Ins/Ins, and 2.23-fold (95% CI: 1.32∼3.77) higher for the combination of -94 Del/Ins and Ins/Ins. However, the -519 C/T, -826 C/T, and -881 A/G gene polymorphisms of the NFKBIA gene showed no significant differences in HCC risk for individuals with NFKBIA -519, -826, or -881 polymorphic genes compared to those with the WT gene. We further explored haplotypes to evaluate the combined effect of the three NFKBIA polymorphisms on HCC susceptibility. Distribution frequencies of NFKBIA -519 C/T, -826 C/T, and -881 A/G haplotypes in our recruited individuals were analyzed. There were three haplotypes with frequencies of >5% among all cases; the most common haplotype in the control was CCA (83.1%), and it was therefore chosen as a reference. After comparison to the reference, haplotypes of -519, -826, and -881 combined did not predict susceptibility to HCC either . In turn, NFKB1 -94 Del/Ins promoter polymorphisms presented significant differences with clinical stage  (p<0.05) and tumor size  (p<0.05) in female HCC patients with at least one NFKB1 -94 Ins polymorphism, while no associations were found in any male HCC patients. A higher proportion of females carrying the NFKB1 -94 Ins polymorphism were in stage I/II than in stage III/IV ; tumor sizes also presented similar results   .NFKB1 and NFKBIA genes did not exhibit significant associations  to study the association with HCC. In the in vitro NFKBIA promoter luciferase assay, constructs with the -826C, -550A, -519T, -826T, -550A, and -519T genotypes were expressed at one-half the activity level of other polymorphic constructs NFKBIA -519T polymorphism was reported to be inversely associated with gastric and liver cancer NFKBIA -519 C/T, -826 C/T, and -881 A/G presented no significant differences in terms of the association with the risk of HCC in Taiwanese patients. It was reported that carrying the NFKBIA -881G and -826T polymorphisms was associated with higher risks of HCC compared to HBV-infected non-HCC subjects, but not in healthy controls The NFKBIA (IκBα) protein is the main regulator of NF-κB activation through conjugation with the NF-κB protein in cytoplasmic sequestration and inhibition of its transcriptional activation NFKB1 promoter has been suggested to enhance the activity and increased the production of transcription factor NF-κB, thus, the hepatocytes may present with higher susceptibility to carcinogenic stimuli and leading to HCC. The main causes of HCC in Taiwan are chronic hepatitis B and C infections, higher than 90% of patients positive for hepatitis B surface antigen (HBsAg) or antibody to hepatitis C virus (anti-HCV) NFKB1 promoter may increase the susceptibility to viral gene products mediated activation and the risk of HCC. This inference was supported by our observations where patients with -94 Ins NFKB1 promoter polymorphism showed a higher incidence of HCC  in HCC cell lines, as well as the underlying mechanisms.In Taiwan, HBsAg was positive in approximately 80% of male patients with HCC in 1981–1983, gradually decreased to 68% in 1996–1998 and to 66% in 1999–2001. It is also of note that HCV has replaced HBV in the viral etiology of HCC gradually, and has become the main etiology of HCC NFKB1 -94 Ins promoter polymorphism appeared to increase the risk of developing HCC. Female HCC patients who carried the -94 Ins polymorphism were associated with a lower clinical stage and a smaller tumor size. The 4-bp promoter polymorphism, -94 Del/Ins, in NFKB1 promoter variants may represent a predisposing factor for HCC susceptibility in the Taiwanese population.In conclusion, we showed that the


Robert Clarke and colleagues conduct a meta-analysis of unpublished datasets to examine the causal relationship between elevation of homocysteine levels in the blood and the risk of coronary heart disease. Their data suggest that an increase in homocysteine levels is not likely to result in an increase in risk of coronary heart disease. MTHFR) appreciably increases homocysteine levels, so “Mendelian randomization” studies using this variant as an instrumental variable could help test causality.Moderately elevated blood levels of homocysteine are weakly correlated with coronary heart disease (CHD) risk, but causality remains uncertain. When folate levels are low, the TT genotype of the common C677T polymorphism (rs1801133) of the methylene tetrahydrofolate reductase gene  and 95% CI comparing TT versus CC homozygotes was 1.02  overall, and 1.01 (0.95–1.07) in unsupplemented low-folate populations. By contrast, in a slightly updated meta-analysis of the 86 published studies , the OR was 1.15 (1.09–1.21), significantly discrepant (p = 0.001) with the OR in the unpublished datasets. Within the meta-analysis of published studies, the OR was 1.12 (1.04–1.21) in the 14 larger studies  and 1.18 (1.09–1.28) in the 72 smaller ones .Nineteen unpublished datasets were obtained  in which multiple genetic variants had been measured, including The CI for the overall result from large unpublished datasets shows lifelong moderate homocysteine elevation has little or no effect on CHD. The discrepant overall result from previously published studies reflects publication bias or methodological problems.Please see later in the article for the Editors' Summary MTHFR gene, uses folate to break down and remove homocysteine so fortification of cereals with folate can reduce population homocysteine blood levels. Pooled results from prospective observational studies that have looked for an association between homocysteine levels and later development of CHD suggest that the reduction in homocysteine levels that can be achieved by folate supplementation is associated with an 11% lower CHD risk.Coronary heart disease (CHD) is the leading cause of death among adults in developed countries. With age, fatty deposits (atherosclerotic plaques) coat the walls of the coronary arteries, the blood vessels that supply the heart with oxygen and nutrients. The resultant restriction of the heart's blood supply causes shortness of breath, angina , and sometimes fatal heart attacks. Many established risk factors for CHD, including smoking, physical inactivity, being overweight, and eating a fat-rich diet, can be modified by lifestyle changes. Another possible modifiable risk factor for CHD is a high blood level of the amino acid homocysteine. Methylene tetrahydofolate reductase, which is encoded by the MTHFR gene—the C677T polymorphism—reduces MTHFR efficiency so TT homozygotes  have 25% higher blood homocysteine levels than CC homozygotes. In meta-analyses  of published Mendelian randomized studies, TT homozygotes have a higher CHD risk than CC homozygotes. Because gene variants are inherited randomly, they are not subject to confounding, so this result suggests that high blood homocysteine causes CHD. But what if only Mendelian randomization studies that found an association have been published? Such publication bias would affect this aggregate result. Here, the researchers investigate the association of the MTHFR C677T polymorphism with CHD in unpublished datasets that have analyzed this polymorphism incidentally during other genetic studies.Prospective observational studies cannot prove that high homocysteine levels cause CHD because of confounding, the potential presence of other unknown shared characteristics that really cause CHD. However, an approach called “Mendelian randomization” can test whether high blood homocysteine causes CHD. A common genetic variant of the MTHFR C677T polymorphism in thousands of people with and without CHD. Meta-analysis of these datasets indicates that the excess CHD risk in TT homozygotes compared to CC homozygotes was 2% , a nonsignificant difference . When the probable folate status of the study populations  was taken into account, there was still no evidence that TT homozygotes had an excess CHD risk. By contrast, in an updated meta-analysis of 86 published studies of the association of the polymorphism with CHD, the excess CHD risk in TT homozygotes compared to CC homozygotes was 15%. Finally, in a meta-analysis of randomized trials on the use of vitamin B supplements for homocysteine reduction, folate supplementation had no significant effect on the 5-year incidence of CHD.The researchers obtained 19 unpublished datasets that contained data on the These analyses of unpublished datasets are consistent with lifelong moderate elevation of homocysteine levels having no significant effect on CHD risk. In other words, these findings indicate that circulating homocysteine levels within the normal range are not causally related to CHD risk. The meta-analysis of the randomized trials of folate supplementation also supports this conclusion. So why is there a discrepancy between these findings and those of meta-analyses of published Mendelian randomization studies? The discrepancy is too large to be dismissed as a chance finding, suggest the researchers, but could be the result of publication bias—some studies might have been prioritized for publication because of the positive nature of their results whereas the unpublished datasets used in this study would not have been affected by any failure to publish null results. Overall, these findings reveal a serious example of publication bias and argue against the use of folate supplements as a means of reducing CHD risk.http://dx.doi.org/10.1371/journal.pmed.1001177.Please access these Web sites via the online version of this summary at American Heart Association provides information about CHD and tips on keeping the heart healthy; it also provides information on homocysteine, folic acid, and CHD, general information on supplements and heart health, and personal stories about CHDThe CHD, including personal stories about CHDThe UK National Health Service Choices website provides information about British Heart Foundation on heart disease and keeping the heart healthyInformation is available from the CHD (in English and Spanish)The US National Heart Lung and Blood Institute also provides information on CHD (in English and Spanish)MedlinePlus provides links to many other sources of information on Mendelian randomization Wikipedia has a page on  In many populations without folic acid fortification, individuals with TT genotype have about 20% higher homocysteine than those with the more common CC genotype MTHFR genotype and, hence, to higher or lower lifelong homocysteine levels The enzyme methylene tetrahydrofolate reductase, encoded by the MTHFR genotype with CHD assess the effects of lifelong homocysteine differences and should not be materially affected by confounding if each study is of a reasonably homogeneous population  MTHFR genotype with CHD risk . CHD was defined as death from CHD, myocardial infarction . We identified a total of 28,617 cases and 41,857 controls in 86 published case-control studies  on this topic seeking data on the MTHFR genotypes and plasma homocysteine levels in disease-free individuals. The search criteria identified 53,595 other disease-free individuals with homocysteine data in 33 other MTHFR publications, yielding a total of 70 published studies of the biochemical effects of MTHFR genotype on homocysteine . None of the unpublished datasets yielded such data, as the investigations were not particularly concerned with homocysteine. Additional eligible studies were identified by searching the electronic literature  using the search terms “cysteine .MTHFR studies. As a surrogate for it, these MTHFR studies were classified by study place and time into five probable folate status categories, on the basis of when national legislation permitting or requiring folic acid fortification came into effect  Mean folate levels and mean log homocysteine by genotype were estimated from individual participant data where available, or from published reports. In calculating these means we sought to give all individuals similar weight, so large studies contribute proportionally more than small ones. . These analyses of within-study percentage differences in homocysteine levels between TT and CC genotypes , and was similar in the datasets with larger and small genotyping panel sizes. Any null bias from nonpublication would have biased the expected log OR in the aggregate of all unpublished studies downwards by only about 0.001  with the results from the unpublished datasets .For the ten large trials of B-vitamins for homocysteine reduction , the probability of a result from a large SNP panel study reaching statistical significance after allowance for multiple testing can be shown to be negligible  may well have appreciably affected the meta-analyses of published studies, nonpublication bias  should have had a negligible effect on the present meta-analyses of unpublished studies. For ORs of the magnitude that may be plausible for The discrepancy between the overall results in the unpublished and the published datasets is too extreme to be plausibly dismissed as a chance finding . Some studies, particularly if small, might have been prioritised for publication by investigators, referees, or editors according to the positivity of their results MTHFR with CHD in published studies, publication bias may also help explain the discrepant findings recently reported for MTHFR and stroke The magnitude of the effect of publication bias is substantial and in addition to distorting the association of MTHFR C677T genotype calls. As these small differences in T-allele frequency correspond to substantial differences in the TT/CC odds Click here for additional data file.Figure S2Screening and selection of population surveys of folate status.(TIF)Click here for additional data file.Figure S3Percent higher homocysteine by MTHFR C677T genotype in 70 biochemical studies of non-CHD populations. Subtotal results are from inverse-variance-weighted averages of within-study differences in log homocysteine, so the 95% CIs for them (solid diamonds) reflect only the within-study variation; other CIs are 99% CIs.(TIF)Click here for additional data file.Figure S4CHD OR  from CC/CT/TT results in 19 unpublished datasets, yielding 24 parts that are classified by probable folate status category: maximum likelihood estimate, assuming that the underlying log OR for CT/CC is 0.25 times that for TT/CC. Black squares indicate OR, and horizontal lines indicate 99% CIs. The subtotals and their 99% CIs are indicated by black diamonds. The overall OR and its 95% CI is indicated by a white diamond. The weight (defined as the inverse of the variance of the maximum likelihood estimate of the log OR) and the product of the weight times OR indicates how much each study has contributed to the subtotals and totals.(TIF)Click here for additional data file.Figure S5CHD OR for MTHFR TT versus CC genotype in 86 published studies, from Table S4, classified by probable folate status category and sorted by effective study size . Weight is the inverse of the variance of the maximum likelihood estimate of the log OR. Additivity of the weights is therefore only approximate. NB, presupplementation Europe subtotal allows for the common control group in Frederiksen-Prospective (P) and Frederiksen-Case-Control (CC). 95% CIs for total; other CIs are 99%.(TIF)Click here for additional data file.Text S1Webmaterial for homocysteine and coronary heart disease: meta-analysis of MTHFR case-control studies, avoiding publication bias.(PDF)Click here for additional data file.


The gene encoding CD14 has been proposed as an IBD-susceptibility gene with its polymorphism C-260T being widely evaluated, yet with conflicting results. The aim of this study was to investigate the association between this polymorphism and IBD by conducting a meta-analysis.Seventeen articles met the inclusion criteria, which included a total of 18 case-control studies, including 1900 ulcerative colitis (UC) cases, 2535 Crohn's disease (CD) cases, and 4004 controls. Data were analyzed using STATA software. Overall, association between C-260T polymorphism and increased UC risk was significant in allelic comparison , homozygote model , as well as dominant model . However, there was negative association between this polymorphism and CD risk across all genetic models. Subgroup analyses by ethnicity suggested the risk-conferring profiles of -260T allele and -260 TT genotype with UC in Asians, but not in Caucasians. There was a low probability of publication bias.CD14 gene C-260T polymorphism might be a promising candidate marker in susceptibility to UC, especially in Asians.Expanding previous results of individual studies, our findings demonstrated that  Crohn's disease (CD) and ulcerative colitis (UC) are the two major subtypes of inflammatory bowel disease (IBD), which is a chronic relapsing and remitting inflammatory condition affecting the gastrointestinal tract. Familial aggregation and twin studies reported that patients with IBD carried strong genetic predisposition CD14 gene is mapped on chromosome 5q31.1, adjacent to a region reportedly in linkage with IBD CD14 gene  results in elevated transcriptional activity and accordingly high serum CD14 levels CD14 for IBD is well-defined and its C-260T polymorphism has been reported to be associated with IBD by some but not all studies Toll-like receptors (TLRs) are a class of proteins that are active in innate and adaptive systems. TLRs are members of a conserved interleukin (IL)-1 superfamily of transmembrane receptors that recognize pathogen-associated molecular patterns (PAMPs) which present on the surface of pathogens. The pathogenesis of IBD, ulcerative colitis and Crohn's disease may be due to increased TLR or decreased TLR signalling respectively CD14 gene C-260T polymorphism with the occurrence of IBD by a meta-analysis, and simultaneously to identify factors attributed to between-study heterogeneity and publication bias.To shed some light on this issue, we sought to examine the association of This meta-analysis is reported in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guideline (please see supplementary PRISMA checklist) We searched the PubMed, EMBASE, ISI Web of Knowledge databases and Wanfang databases before July 20, 2012, by using the key subjects “inflammatory bowel disease”, “IBD”, “Crohn's disease”, “CD”, “Ulcerative colitis”, “UC”, in combination with “Cluster of differentiation 14”, “CD14 ”, “toll like receptor 4”, “TLR4” and “TLR-4”. We read the full text of the retrieved articles to inspect whether data on the topic of interest were included. Reference lists of the retrieved articles and systematic reviews were also checked for citations of articles that were not initially identified. Special meeting issues of journals (Abstract only) were removed from the searching results. Search results were restricted to human populations and articles written in English or Chinese. If more than one geographic or ethnic heterogeneous group was reported in one report, each was extracted separately. If two or more studies shared the whole or part of study populations, the one with larger sample size was extracted.CD14 gene C-260T polymorphism with the risk for IBD (CD and/or UC); (2) case-control or cross-sectional or nested case-control study in design; (3) availability of genotype or allele counts of studied polymorphisms between patients and controls in order to estimate odds ratio (OR) and its corresponding 95% confidence interval (CI).Identified studies satisfied the following criteria: (1) evaluation of The following data were extracted independently and entered into separate databases by two authors (Z. Wang and J. Hu) from each qualified study: first author's last name, publication year, population ethnicity, study design, genotyping methods, baseline characteristics of the study population including age, gender, subtype of the disease, and the genotype or allele distributions in patients and controls. Any encountered discrepancies were adjudicated by a discussion and an 100% consensus was reached.CD14 gene C-260T polymorphism with IBD risk under allelic, homozygous and dominant and recessive models, respectively. Crude OR and 95% CI were calculated to compare contrasts of alleles or genotypes between patients and controls.In this meta-analysis, we assessed the association of 2 test. The random-effects model using DerSimonian & Laird method was employed to bring the individual effect-size estimates together irrespective of between-study heterogeneity I2 statistic, which was documented for the percentage of the observed between-study variability due to heterogeneity rather than chance with its values ranging 0–100% [I2 = 0–25%, no heterogeneity; I2 = 25–50%, moderate heterogeneity; I2 = 50–75%, large heterogeneity; I2 = 75–100%, extreme heterogeneity Deviation from Hardy-Weinberg equilibrium was assessed using Pearson χFinally, evidence for publication bias was assessed using Egger's test and visual funnel plot inspection. The Egger's test detects funnel plot asymmetry by determining whether the intercept deviates significantly from zero in a regression of the standardized effect estimates against their precision.I2 statistic and publication tests, where a significance level of less than 0.1 was chosen. Statistical analyses were performed using STATA version 11.0 for Windows .Probability less than 0.05 was judged significant with the exception of the CD14 gene C-260T polymorphism with IBD The detailed selection process is presented in The baseline characteristics of all qualified studies are presented in CD14 polymorphism and increased UC risk in allelic comparison  with low possibility of publication bias as reflected by the suggestive asymmetry of funnel plot . The magnitude of OR in allele comparison was similar to the homozygote  as well as dominant models , while no significant association was found in recessive model .The pooled OR from all included studies indicated a significant association between nel plot  and the Considering the fact that study design, the ethnicity difference, as well as the method of genotype might attribute to the sources of heterogeneity, we conducted separate analyses according to these factors.CD14 C-260T polymorphism and UC risk was observed across all genetic models, in the hospital-based subgroup , whereas this effect was reversed in Taqman or Probe subgroup studies with no attainable significance .CD14 C-260T polymorphism in allele comparison , homozygote , dominant model  and recessive model , even in Asians or Caucasians stratified by ethnicity. However, subgroup analyses by study design detected significance for allele comparison , homozygote model  with increased CD risk, in hospital-based studies, even for the recessive models . When we conducted an stratified analysis by the genotyping methods, there were obvious differences. For example, a increased risk was observed in allele comparison  and homozygote model  for PCR-based subgroup; whereas no materially change in odds was observed in Taqman or Probe subgroup studies 2/caspase-activation recruitmentdomains (CARD)-15 polymorphisms have been strongly associated with CD in Caucasians CD14 gene C-260T polymorphism exhibited remarkable heterogeneity with UC across ethnic groups, with significance attained in Asians but not in Caucasians, suggesting that CD14 C-260T might exert a pleiotropic impact in the pathogenesis of UC or interact with other genetic or environmental factors. Furthermore, CD14 is a monocytic differentiation antigen that regulates innate immune responses to pathogens. CD14 C-260T polymorphism has been reported to be associated with some immune-related diseases, such as allergic rhinitis It is inevitable to encounter genetic heterogeneity in any disease identification strategy CD14 gene C-260T polymorphism with UC risk was observed across all genetic models in hospital-based studies, we run the risk of overestimating this association in view of the striking weaknesses of this type of design, such as population stratification and admixture. To obtain convincing evidence, well-designed studies with less error-prone methods are encouraged.Besides the disturbing influence of ethnicity in this meta-analysis, it should still be treated with caution that differences in study design constituted another potential source of heterogeneity. Although positive association of CD14 polymorphism in the IBD different subgroups. Given the insufficient study power in each subgroup, much more research within the framework of genetics and biology is warranted.So far, as two major subtypes of IBD, CD and UC are believed to share overlapping but distinct clinical and pathological features, and have great differences in etiology and genetic backgrounds CD14 gene C-260T polymorphism individually make a moderate contribution to risk prediction in UC patients, but whether the polymorphism integrated with other risk factors will enhance the prediction requires additional research. Thus, a more precise analysis should be conducted with individual data, which would allow for the adjustment by other co-varieties such as age, gender, lifestyle and other genetic factors.Despite the clear strengths of our study including relatively large sample sizes and robustness of statistical analyses, interpretation of our current study, however, should be viewed in light of several technical limitations. First, all included studies were cross-sectional in design, which precludes us to make inference on causality. Second, because only published studies were retrieved and articles in languages other than English or Chinese were not included, publication bias might be possible, even though our funnel plots and statistical tests indicated no observable bias. Third, our results were based on unadjusted estimates. It seems likely that the CD14 gene C-260T polymorphism might contribute to the occurrence of UC, especially in Asians. Also our observations leave open the question regarding the heterogeneous effect of -260T allele across different ethnic populations. Nonetheless, for practical reasons, we hope that this study will not remain just another endpoint of research instead of a beginning to establish the background data for further investigation on pathphysiological mechanisms of CD14 gene on IBD.Taken together, we expand previously individual studies on IBD by suggesting that Text S1Checklist of items to include when reporting a systematic review or meta-analysis (diagnostic review consisting of cohort studies).(DOC)Click here for additional data file.


Previous studies have investigated the association between single nucleotide polymorphisms (SNPs) located in microRNAs (miRNAs) and breast cancer susceptibility; however, because of their limited statistical power, many discrepancies are revealed in these studies. The meta-analysis presented here aimed to identify and characterize the roles of miRNA SNPs in breast cancer risk, and evaluate the associations of polymorphisms in miR-146a rs2910164, miR-196a rs11614913 and miR-499 rs3746444 with breast cancer susceptibility, respectively.st December, 2012. The complete data of polymorphisms in miR-146a rs2910164, miR-196a rs11614913 and miR-499 rs3746444 from case-control studies for breast cancer were analyzed by odds ratios (ORs) with 95% confidence intervals (CIs) to reveal the associations of SNPs in miRNAs with breast cancer susceptibility. Totally, six studies for rs2910164 in miR-146a, involving 4225 cases and 4469 controls; eight studies for rs11614913 in miR-196a, involving 4110 cases and 5100 controls; and three studies of rs3746444 in miR-499, involving 2588 cases and 3260 controls, were investigated in the meta-analysis. The rs11614913 (TT+CT) genotype of miR-196a2 was revealed to be associated with a decreased breast cancer susceptibility compared with the CC genotypes ; however, no significant associations were observed between rs2910164 in miR-146a (or rs3746444 in miR-499) and breast cancer susceptibility.The PubMed and Embases databases were searched updated to 31This meta-analysis demonstrates the compelling evidence that the rs11614913 CC genotype in miR-196a2 increases breast cancer risk, which provides useful information for the early diagnosis and prevention of breast cancer. MicroRNAs (miRNAs) are non-coding RNA molecules that can act as tumor suppressor genes or oncogenes et al. reported that the SNPs rs11614913 in miR-196a2, rs3746444 in mir-499 and rs2910164 in miR-146a were not related to breast cancer risk Several miRNA polymorphisms have been reported to affect miRNA processing or miRNA-mRNA interactions Meta-analysis is statistical methods for contrasting and combining results from different studies, in the hope of identifying sources of disagreement among those results st December, 2012, were limited to human species, female sex and cancer subjects of adult patients (19+ years). All the titles and abstracts of searched articles were reviewed to exclude clearly irrelevant studies. The full texts of the remaining articles were read, and a manual search of the references from original studies was performed to identify additional articles of the same topic.PubMed and Embases databases were searched with the following terms: “breast cancer/carcinoma”, “polymorphism/variant”, “miR-146a/rs2910164”, “miR-196a2/rs11614913” or “miR-499/rs3746444”. The searched articles, published in English language updated to 31All the case-control studies were studied according to the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) as a previous report P value for Hardy-Weinberg equilibrium (HWE) of controls. In case of disagreement, another reviewer (Zhong-Hua Jiang) resolved these disagreements according to the original data.Two reviewers (Zong-Hua Gao and Xin-Xin Li) extracted data independently using standardized forms. The following characteristics were collected from each study if available: (1) publication year; (2) first author's name; (3) country origin; (4) ethnicity were categorized as Caucasian, and non-Caucasian; (5) genotyping methods; (6) total numbers of cases and controls; (7) miR-146a, miR-196a and miR-499 polymorphism distribution data, respectively; (8) http://ihg.gsf.de/cgi-bin/hw/hwa1.pl), and P value <0.05 was considered significant. The ORs with their corresponding 95% CIs  were calculated to analyze the associations of polymorphisms  with breast cancer susceptibility. The significance of the pooled ORs was checked by the Z test, and statistical significance was defined as P value <0.05.Deviation in the controls of all studies from HWE tests were carried out online using a web-based program  was chosen. Otherwise, the fixed effects model (Mantel-Haenszel) was appropriately used to calculate the pooled ORs.Cochran P value <0.10 was considered as the representative of statistically significant publication bias Publication bias was evaluated using the Begg-Mazumdar adjusted rank correlation test and the Egger regression asymmetry test, Eligible studies were selected according to the inclusion and exclusion criteria . Thirty-P>0.05) in most of the studies, but some parts of the data in Catucci's P<0.05). Begg-Mazumdar adjusted rank correlation test and the Egger regression asymmetry test were used to assess the publication bias of the currently available literature.Characteristics of the included studies were shown in P = 0.019), we deleted the data to analyze the associations of rs2910164 in miR-146a with breast cancer susceptibility; no significant risk associations were observed between them.The meta-analysis results of the three SNPs in the miRNAs and breast cancer risk were shown in P = 0.008) and the included population was mixed, we found that the heterogeneities of the miR-196a2 SNP data were reduced and the genotypic results were more credible. In the comparision of genotypes (TT+CT) vs CC, obvious heterogeneity  was reduced to little heterogeneity . Then, the fixed effect model was used and a significant difference was observed between the (TT+CT) genotype and breast cancer susceptibility . Because the limit of the published article number, we did not perform the subgroup analysis by publication year.Significant heterogeneities in the data of miR-196a2 rs11614913 SNPs were observed in P>0.05) and Egger's tests (P>0.05).All the results for the three SNPs in the miRNAs obstained from random model or fixed model were similar. No publication bias was found in this meta-analysis using Begg's  and removed this data from our meta-analysis. But, this data was calculated in Europeans in Lian's study Polymorphism rs2910164 in miR-146a is located in the 3p strand and comprises a G to C change, which results in a change from a G∶U pair to a C∶U mismatch in the stem structure of the miR-146a precursor and alters the expression of mature miR-146a to influence cancer risk et al. reported that the expression level of miR-196a was significantly higher in hepatocellular carcinoma patients with the CC genotype (or at least one C genotype) than in patients with the TT genotype Polymorphism rs11614913 in miR-196a2, which is located in the 3′ mature sequence of miR-196a2, may affect pre-miRNA maturation Polymorphism rs3746444 in miR-499 involves an A to G nucleotide substitution, which leads to a change from an A∶U pair to a G∶U mismatch in the stem structure of the miR-499 precursor Sample size is an important parameter for investigating the genetic effect of any SNP. Our meta-analysis provided higher and sufficient numbers of cases and controls than a single study, significantly increasing the statistical power. In addition, we assessed the qualities of the studies in this meta-analysis, which improved the reliability of the results.Although meta-analysis is robust, there are still several limitations in this study. First, our study did not evaluate any potential gene-gene interaction and gene-environment interactions. Second, our analysis was based on English publications, which may have introduced a language bias. Last, a lack of sufficient eligible studies limited further subgroup analyses.In conclusion, this study demonstrates that SNP rs11614913 in miR-196a2 plays a crucial role in the development of breast cancer. We found no significant associations of polymorphisms rs2910164 in miR-146 and rs3746444 in miR499 with breast cancer susceptibility. Well-designed studies with larger sample sizes are needed to confirm the roles of these miRNA polymorphisms in breast cancer risk.Checklist S1PRISMA 2009 Checklist for this Meta-analysis.(DOC)Click here for additional data file.


Introduction: Risk of testicular germ cell tumors (TGCT) is consistently associated with a history of cryptorchidism (CO) in epidemiologic studies. Factors modifying the association may provide insights regarding etiology of TGCT and suggest a basis for individualized care of CO. To identify modifiers of the CO-TGCT association, we conducted a comprehensive, quantitative evaluation of epidemiologic data.Materials and Methods: Human studies cited in PubMed or ISI Web of Science indices through December 2011 and selected unpublished epidemiologic data were reviewed to identify 35 articles and one unpublished dataset with high-quality data on the CO-TGCT association. Association data were extracted as point and 95% confidence interval estimates of odds ratio (OR) or standardized incidence ratio (SIR), or as tabulated data. Values were recorded for each study population, and for subgroups defined by features of study design, CO and TGCT. Extracted data were used to estimate summary risk ratios (sRR) and evaluate heterogeneity of the CO-TGCT association between subgroups.Results: The overall meta-analysis showed that history of CO is associated with four-fold increased TGCT risk [RR = 4.1(95% CI = 3.6–4.7)]. Subgroup analyses identified five determinants of stronger association: bilateral CO, unilateral CO ipsilateral to TGCT, delayed CO treatment, TGCT diagnosed before 1970, and seminoma histology.Conclusions: Modifying factors may provide insight into TGCT etiology and suggest improved approaches to managing CO. Based on available data, CO patients and their parents or caregivers should be made aware of elevated TGCT risk following orchidopexy, regardless of age at repair, unilateral vs. bilateral non-descent, or position of undescended testes. Cryptorchidism (CO), or undescended testis, affects approximately 3% of all male live births, making it one of the most common congenital disorders. Despite a high rate of spontaneous resolution during the first year of life, CO is firmly established as the primary risk factor for subsequent development of testicular germ cell tumors (TCGT)  to 18 (95% CI = 12–26),  Pubmed interface without language restrictions for human studies published through December 2011, using key words “CO,” “undescended testicle,” “undescended testis,” “undescended testes,” “case-control study,” “cohort study” in combination with “testicular cancer,” “testicular carcinoma,” “testicular neoplasia,” “testis cancer,” “testis carcinoma,” “testis neoplasia,” reviewing also reports cited in retrieved articles and review articles, and by citation indices (ISI Web of Science) for these reports. We also sought high-quality unpublished data. The Review Protocol has not been registered.A genetic counselor and a statistician reviewed retrieved articles to determine eligibility for the meta-analysis, resolving conflicts by consensus among themselves and an epidemiologist. Data on study design, overall CO-TGCT associations, and subgroup-specific CO-TGCT associations were extracted systematically by a single reviewer and confirmed by two others. We eliminated redundant data arising from repeated publication, consulting original authors whenever possible.CI, p-value). When only a point estimate was reported, we requested corresponding variance term from original authors. If the OR estimate was not provided, we calculated it from published tabular data.We extracted published information on RRs relating CO to TGCT as follows: when provided, we recorded point estimates of the odds ratio (OR) for case-control studies and standardized incidence ratio (SIR) for cohort studies, with corresponding standard error or information from which it could be calculated , country where study was conducted, race/ethnicity of participants, and source of CO data . For case-control and cohort studies we noted source of reference group . We distinguished published RR estimates extracted from those we calculated from published data; for published estimates, we tabulated covariates and matching variables in original analyses.Table S3, footnotes b–d).When possible we extracted or calculated RR estimates of CO-TGCT association for subgroups defined by each of several features of CO: laterality of undescended testicle relative to TGCT , level of maldescent , whether definition of CO included spontaneous descent, means of resolving CO , and age at resolution. For this variable we used frequently published categories  (United Kingdom Testicular Cancer Study Group (UK), We extracted or calculated RR estimates for subgroups defined by histology , mixed GCT, seminoma). A separate code for mixed GCT was introduced in 1990 (ICD-0-2), and tumors of mixed histology were previously coded as non-seminoma. Therefore, for studies including diagnoses before 1990, if authors did not specify that non-seminoma excluded mixed histology, we coded reported non-seminoma as “non-seminoma/mixed GCT.” As a measure of year of TGCT diagnosis, we determined midpoint of range of years of diagnosis among cases participating in each study.Original population-based case-control data  and cohort  studies, with summary measures subsequently pooled. Resulting sRR estimates  summarize available data on CO-TGCT associations from studies with reference groups judged comparable to cases. Other articles compared CO prevalence of TGCT cases with CO prevalence from external populations, rather than source population of the cases; limited comparability in such studies is now recognized as a potential source of severe bias .Meta-analyses were performed separately for case-control , or were duplicate reports of data included in the analysis . Data from 35 of the remaining 42 reports and raw data from one unpublished case-control study contributed to meta-analyses on which we base our inferences . We requested from authors of three of these reports , case-control data (p = 0.34), or these data types combined (p = 0.40); however, addition of data from the TGCT case series introduced an impression of substantial publication bias (p = 0.01). Visual inspection of Begg's funnel plots showed that while magnitude and standard error of RR estimates from most cohort and case-control studies (34 of 36) are within the 95% confidence limits . Egger's tests revealed no evidence of publication bias among cohort data  in case-control studies (Table S2Ai) and 4.8(95% CI = 3.2–7.2) in cohort studies (Table S2Bi). The sRR estimated by pooling these results was 4.1(95% CI = 3.6–4.7), with 14% of the variance (I2) attributed to between-study heterogeneity . By contrast, sRR estimated from studies that compared CO frequencies between TGCT case series and external populations was 14.8(95% CI = 10.7–20.4), with 86% of variance attributed to between-study heterogeneity .We estimated sRR of developing TGCT following a history of CO to be 4.0(95% CI = 3.5–28.2), in the single study , in the single study . Accordingly, this study was a clear outlier in the funnel plot . Analyses stratified on laterality of undescended testes relative to TGCT revealed an apparent trend: sRR estimates increased steadily in progression from TGCT arising in testes contralateral to unilateral CO [sRR = 1.5(95% CI = 0.9–2.6)], on unspecified side relative to unilateral CO [sRR = 3.5(95% CI = 2.7–4.7)], ipsilateral to unilateral CO [sRR = 5.4(95% CI = 3.7–7.8)], and in either testis following bilateral CO [sRR = 9.8(95% CI = 6.2–15.7)] . Data on anatomic location of undescended testes, provided for no case-control study and only one cohort study . Therefore, the meta-analysis did not confirm the report from a single TGCT case series .Several features of CO appeared to modify the CO-TGCT association ], testes repositioned by surgery or hormone therapy [sRR = 4.7(95% CI = 3.7–6.1)], and testes remaining undescended [sRR = 6.2(95% CI = 3.7–10.4)] . Analyses stratified on both means of resolution and age at resolution suggested greater RR among those with older age at spontaneous descent or therapeutic resolution, although estimates for those who experienced spontaneous descent did not achieve statistical significance .In analyses stratified on means of resolving CO, estimates increased in the progression of testes that descended spontaneously  than for ipsilateral testes [5.4(95% CI = 3.7–7.8)], suggesting a deleterious effect of suprascrotal position. Also consistent with positional effects, sRR among those with bilateral non-descent [9.8(95% CI =6.2–15.7)] was, within statistical precision of the meta-analysis, indistinguishable from twice sRR of those with unilateral non-descent [2×sRRipsilateral = 10.8(7.4–15.6)]. However, published data are insufficient (24 cases in 7 studies) to rule out a small increase in risk to contralateral testes , as would be required to strictly affirm Hussman's first prediction. We note, however, that some true increase in risk to contralateral testes would not necessarily rule out the position hypothesis, because central responses to a single testis in a suprascotal position could, in theory, contribute to malignant potential of the contralateral testis. For example, in rodent models of unilateral CO created surgically, degenerative changes  in s Quinn,  and altes Quinn,  were demUnfortunately, published data could not distinguish between risks experienced by men with histories of abdominal vs. inguinal non-descent. These distinct phenotypes may provide a means of determining relevance to human CO and TGCT of animal models of CO with high , raises the intriguing possibility that increasing occurrence of seminoma may involve increasing exposure to unidentified environmental factors through processes unrelated to CO.Morrison  apparentIn conclusion, this meta-analysis provides a detailed quantitative summary of available high-quality observational data on the association between CO and TGCT, including observations that can no longer be made due to trends toward younger age at CO repair and increasing TGCT incidence. Results of subgroup analyses indicate possible future directions in understanding both stratification of TGCT risk among boys born with undescended testes and TGCT etiology. Meta analyses addressing features of CO suggest that while bilateral CO is associated with nearly twice the TGCT risk as unilateral CO, data are inadequate to assess the role of anatomic position of the undescended testis. Early repair is associated with lower TGCT risk, but published data do not provide a basis for recommending optimal time of repair or to determine whether optimal repair can reduce risk to baseline. Therefore, all CO patients and their families should be counseled to be aware of future risk. Additional data are needed to affirm the possibility that TGCT risk is not elevated among boys whose testes descend spontaneously after birth. Results of subgroup analyses addressing features of TGCT suggest multiple pathways to malignancy and indicate considerable heterogeneity in risk of TGCT following CO. Both possibilities warrant mechanistic examination using contemporary tools of molecular biology.The authors dedicate this report in memory of the life and work of our esteemed colleague, Dr. Brian E. Hardy.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.


Impulsivity is a multidimensional construct which has been associated with dopaminergic neurotransmission. Nonetheless, until this moment, few studies addressed the relationship between different types of impulsivity and the single nucleotide polymorphism caused by a substitution of valine  with methionine (met) in the 158 codon of the Catechol-o-Methyltransferase gene . The present study aimed to investigate the association between val158met COMT polymorphism and impulsive behavior measured by two neuropsychological tests.We administered two neuropsychological tests, a Continuous Performance Task and the Iowa Gambling Task were applied to 195 healthy participants to characterize their levels of motor, attentional and non-planning impulsivity. Then, subjects were grouped by genotype, and their scores on impulsivity measures were compared. There were no significant differences between group scores on attentional and motor impulsivity. Those participants who were homozygous for the met allele performed worse in the Iowa Gambling Task than val/val and val/met subjects.Our results suggest that met allele of val158met COMT polymorphism is associated with poor performance in decision-making/cognitive impulsivity task. The results reinforce the hypothesis that val and met alleles of the val158met polymorphism show functional dissociation and are related to different prefrontal processes. Impulsivity has been considered both a personality trait and a pattern of response with different presentations and outcomes. Moeller and colleagues , for insBechara and Van der Lynden  have proA relationship among dimensions of impulsive behaviour has also been found at the molecular level. Components of the monoaminergic and other neurotransmitter systems seem to play a differential role in impulsivity expression . The doprs4680 , which produces a substitution of the amino acid methionine (met) for valine  at codon 158 in the COMT gene. The met allele enzyme has one-third to one-half of the activity of the val allele variant [A key gene polymorphism that may influence both the dopaminergic system and impulsivity is the catechol-O-methyltransferase enzyme (COMT) . It acco variant . Therefo variant .Several studies aiming to assess functional differences between subjects with different val158met polymorphisms have shown that those homozygous for Met alleles show better performance in cognitive functions related to frontostriatal networks, such as executive function ,17.11. These are more reliable than self-report questionnaires because behavioural tests are independent of recall and interpretation of past behaviour [Concerning impulsivity, Forbes and colleagues  did not ehaviour . In prevehaviour ,20–23.Despite previous evidence that higher COMT metabolism was associated with better performance in CPT , its is The aim of this study was to investigate the hypothesis that the functional differences between the met and val COMT alleles affect impulsive behaviour. In particular, we aimed to assess the hypotheses that homozygosity at the met allele leads to better performance in at least two tasks related to frontostriatal circuits in a healthy subject’s sample.The study was approved by the Universidade Federal de Minas Gerais ethics committee and was conforming to the principles expressed in the Heksinki Declaration. All subjects signed a study informed consent. We assessed 195 healthy adults from the city of Belo Horizonte, Brazil. The participants were invited by local announcements at two Universities and the researcher’s network. The inclusion criteria were age between 18 and 60 years, at least 11 years of formal education, familiarity with the computer/mouse interface, no severe sensory or motor impairments and no history of psychiatric or neurological disorders. To ensure lack of psychiatric conditions, the MINI neuropsychiatric interview  was usedThe neuropsychological assessment has been described elsewhere  appears on the screen. Omission errors occur when the individual does not press the spacebar when a letter (except X) appears on screen, and reflect instances when the participant is not attentive to the target stimuli. A commission error occurs when the subject presses the spacebar when the letter X appears on screen, reflecting a flaw in motor response inhibition. These two measures are similar to attentional and motor impulsiveness, respectively, in Barratt’s model of impulsiveness . Thus, wIn the IGT, subjects have to choose one card at a time from four available decks . The task requires the subjects to make 100 choices , and in each trial, subjects may win or lose a certain amount of money. During the instructions, subjects are told that some decks are more advantageous than others, but they do not know which are the better decks. After each choice, subjects receive feedback on the computer screen telling them how much money they won or lost. Using the feedback, the subject has to avoid decks that yield high immediate gains but lead to large future losses (decks A and B) and choose the decks that lead to small immediate gains but avoid substantial losses throughout the task (decks C and D). One hundred choices are divided into five blocks, with twenty choices each. This type of register is important to verify changes in the pattern of choices during the task, such as the learning curve. A total Netscore (number of cards selected from the advantageous “good” decks minus the disadvantageous “bad” decks) was used. This test is a good model for studying non-planning/cognitive impulsivity .rs4680) were purchased in a made-to-order from Applied Biosystems®. Genotyping was performed using a real-time PCR system in the allelic discrimination mode  using the TaqMan Genotyping Master Mix . PCR parameters included an initial denaturation at 95°C for 10 min, followed by 50 cycles at 95°C for 15 seconds and 60°C for 1 minute. Each reaction contained 3.5 µl of Mix, 0.1 µl of probe, 3.4 µl of deionised water and 1.0 µl of DNA. Researchers involved in genotyping were blind to neuropsychological results, and researchers involved in neuropsychological assessments were blind to the genotyping results. COMT genotype was coded as a categorical variable  for further analysis.The polymorphism was assessed by a standard procedure previously reported . BrieflyThe distribution of impulsivity data, assessed by the Kolmogorov-Smirnov Test, violated the normal distribution for the CPT variables (p<0.05) but not for the IGT net score (p=0.667). Data transformations were performed aiming to normalise CPT scores, but none succeeded, so non-parametric tests were used for the CPT analysis and parametric tests for the IGT analysis. First, the influence of age, education and gender on test performance was assessed by correlation analysis. Variables significantly related to neuropsychological performance were controlled for the following procedure. To assess the influence of COMT genotype on impulsivity, Generalized Linear Models were adopted for the CPT data. The models for ordinal response (logistic) were built independently, with the CPT measures as dependent variables, the COMT polymorphism as a factor and, if necessary, sociodemographic variables as covariates. Main effects and interactions between factors were computed. The procedure for IGT data was similar, but a parametric procedure was performed. Statistical significance was established at 0.05. All statistical procedures were performed using SPSS 19.0 .2=2.49, p=0.114). Participant descriptions and neuropsychological test data stratified by COMT Genotype are shown in The COMT genotype distribution was under Hardy-Weinberg equilibrium . Age influenced the number of Commission Errors  and Reaction Time  but not Omission Errors (p=0.513). Education influenced Commission Errors  and Response Time  but not Omission Errors (p=0.318). Age and Education were used as covariates on the Commission and Response Time Generalized Linear Models. Considering the IGT, no significant correlations were found between the Netscore and sociodemographic variables (p>0.05).2=13.76, df = 4, p=0.008), and age  but not Education  or COMT Genotype  influenced test performance. The same pattern was observed for the CPT Response Time model , with a significant influence of age  but not Education  and COMT Genotype  on motor impulsivity measures. The model of CPT Omission Errors was not significant . The Generalized Linear Model for CPT Commission errors was significant (χ2=0.05). Levene’s test suggests that the error variance was homogeneous across the COMT Genotype groups . Post-hoc analysis was performed using the conservative Sidak’s test, and Cohen’s d was adopted as an estimate of effect size. These results do not show significant differences between met/met and val/met groups , but significant differences were found when met/met and val/val  were compared, as well as for met/val and val/val , indicating that a more impulsive pattern of response was shown by met carriers. Effect sizes between val/val carriers and the other two COMT Genotype groups can be considered moderate. These comparisons are shown in For the IGT Netscore, the General Linear Model containing only the COMT Genotype as a predictor was significant , with a moderate effect size , related to striatal dopaminergic neurotransmission, were associated to impulsivity self-reported measures and striatal reactivity paradigm. In the same study authors did not find any association between COMT val158met polymorphism and impulsivity measures. These data are, in some way, different from those reported in the present study. This difference could be explained by the fact that Iowa Gambling Task seems to be influenced by another executive functions processes more related to cortical dopaminergic activity as, for instance, working memory [vs subcortical dopaminergic neurotransmission and its relationship with different types of impulsive behaviour.In addition, there is evidence that some aspects of impulsive behaviour are more related to striatal dopaminergic activity in comparison to prefrontal dopaminergic neurotransmission. For example, Forbes et al. , found tg memory . Future Concerning our sample two limitations must to be considered. First, the present sample is composed by students and is not a representative sample. Replication of the present study in a more representative sample and specific clinical groups is needed to assess the validity of the results. A second sample limitation is the imbalance of male/female ratio. The differences between impulsivity among males and females are controversial with both positive and negative findings –47. In tIn conclusion, regardless of the limitations already mentioned, we consider that the present study made contributions to our understanding of the relationship between the COMT val158met polymorphism and a specific type of impulsive behaviour. On the other hand, we did not find a relationship between these polymorphisms and motor and attentional impulsivity. These data reinforce the hypothesis that different aspects of impulsivity are independent and stem from a different neurobiological basis. In comparison to previous studies that correlated IGT scores and the val158met polymorphism, we have recruited a larger sample. Future studies including patients affected by psychiatric disorders are required to clarify the relationship between impulsivity and the COMT val158met polymorphism.


Mycobacterium avium subspecies paratuberculosis (MAP) is an infective agent found in ruminants and milk products, which has been suggested to increase the risk of gastrointestinal inflammation in genetically susceptible hosts. It is hypothesized that lactase persistence facilitates exposure to such milk products increasing the likelihood of adverse outcomes. Individuals either homozygous or heterozygous for the T allele of DNA variant, rs4988235, located 14kb upstream from the LCT locus, are associated with having lactase persistence.The aim of this study was to determine whether lactase persistence as evident by the T allele of rs4988235 is associated with Crohn's Disease (CD) in a New Zealand population.Individuals homozygous for the T allele (T/T genotype) showed a significantly increased risk of having CD as compared with those homozygous for the C allele . Additionally, a significant increase in the frequency of the T allele was observed in CD patients , indicating that the T allele encoding lactase persistence was associated with an increased risk of CD.Our findings indicate that lactase persistence as evident by the presence of the T allele of rs4988235 is associated with risk of CD in this New Zealand Caucasian population. Mycobacterium avium subsp. Paratuberculosis (MAP) exposure has resurfaced within the literature as a potential environmental variant that may be implicated in the development of CD [Crohn's Disease (CD) is a form of inflammatory bowel disease of both genetic and environmental aetiology. Somewhat controversially nt of CD . MAP is nt of CD . MAP is nt of CD  and is dnt of CD  due to int of CD ,6.One of the most important factors that may influence the amount of milk consumed, and hence exposure to MAP in humans relates to the presence of Lactase-Phlorizin Hydrolase (lactase) in the small intestinal mucosa. Lactase is the enzyme required to hydrolyse lactose, the sugar found in milk products, into its constituent galactose and glucose . InfantsLCT locus that demonstrated complete agreement with clinically identified lactase non persistence in a Finnish population. LCT is a gene which encodes Lactase Phlorizin Hydrolase (LPH) for the hydrolysis of lactose. Homozygotes for the C allele of rs4988235 were found to be lactase-non persistent, whilst those heterozygous or homozygous for the T allele were determined to be lactase persistent. This finding has been replicated in several other European populations [in vitro [Ennatah et al  identifiulations ,12 and sin vitro . Thus thEvaluating the association of lactase persistence with CD as a key factor influencing exposure to MAP via the consumption of milk products is particularly important in New Zealand, a country with one of the highest incidences of CD in the Western world at 16.5/100,000 per year  coupled The aim of this study was to determine whether lactase persistence as evident by the presence of the T allele of rs4988235 is associated with CD in a New Zealand population.The Auckland CD Project is a population-based study of genetic and environmental determinants of CD aetiology. CD patients were recruited between May 2005 and April 2007 through local doctors and surgeries in Auckland, New Zealand, and also other North Island centres, by media campaigns, e.g. local newspaper and television. Controls were recruited by the same means, and also recruited from non-affected family members and friends of CD patients. Participants consented to collection of peripheral blood for DNA extraction and genotyping.A total of 945 subjects (333 CD patients and 612 controls) consented to take part. The cases in this study are a subset of the Caucasian participants of the Auckland CD Project. Their gastroenterologists were approached, clinical records scrutinised to confirm diagnosis, and CD was defined using standard diagnostic criteria . Cases wThe study was conducted under ethical protocol MEC/04/12/011, authorised through the New Zealand Multi-Region Human Ethics Committee. All study subjects gave informed consent.DNA was extracted from blood samples or buccal swabs using Qiagen's DNA extraction kit  and following the manufacturer's instructions.Genotyping of rs4988235 was performed using the ABI TaqMan MGB diallelic discrimination system with forward and reverse primer sequences 5'-CTG CGC TGG CAA TAC AGA TAA G-3' and 5'AAA TGC AAC CTA AGG AGG AGA GTT C-3' respectively and VIC-- ATA ATG TAG TCC CTG GCC T and FAM--ATA ATG TAG CCC CTG GC probes . The reactions were prepared using 2× TaqMan Universal Master Mix, 40× SNP Genotyping Assay Mix, DNase-free water, and 10 ng genomic DNA in a final volume of 5 ul per reaction. The PCR amplification was performed using the ABI Prism 7900 HT sequence-detector machine under the following conditions: 50°C for 2 minutes, 10 min 95°C enzyme activation followed by 40 cycles at 95°C for 15 sec and 60°C for 1 min .To reduce the possibility of genotyping error, genotyping was repeated utilising different primers (5'-CTC TGC GCT GGC AAT ACA G and 5'-AAA TGC AAC CTA AGG AGG AGA) and probes (VIC-ATA AGA TAA TGT AGC CCC TGG C and FAM- ATA AGA TAA TGT AGT CCC TGG C)  under the following conditions: 60°C for 1 minute, 95°C for 10 minutes, followed by 55 cycles of 92°C for 15 s and 60°C for 1 minute and 60°C for 1 minute.The allelic discrimination results for both sets of genotyping were determined after the amplification by performing an endpoint read.http://www.hapmap.org.Assays were optimized in 24 samples consisting of 20 reference Centre d'Etude du Polymorphisme Humain (CEPH) samples and 4 blanks. All sample plates contained cases, controls, blanks, CEPH and duplicate samples. Quality control measures included independent double genotyping, blind to sample identity and blind to the other caller, and comparison of our CEPH genotypes to those in the HapMap The allelic trend test  was usedGenotypic analysis was carried out and the allelic odds ratio with confidence interval was calculated to test the effect of the T allele on CD risk.SAS  and R  were used for statistical analyses.The genotypes did not meet Hardy-Weinberg equilibrium (HWE) for both the cases and controls. To ensure genotyping errors did not exist in the data, genotyping was repeated using an alternative primer and probe set and the genotypes were confirmed to be correct. Also, the minor allele frequency was 0.273 which is similar to the HapMap CEU population frequency of 0.274. Deviations from HWE may have resulted by chance, as a result of population admixture or perhaps the rs4988235 SNP is associated with a currently unknown factor in controls.For rs4988235, the T/T genotype showed a significantly increased risk of having CD as compared with the C/C genotype  however, no significant difference was found between C/T and C/C. Additionally, a significant increase in the frequency of the T allele was observed in CD patients , indicating that the T allele encoding lactase persistence was associated with risk of CD  had relatives with IBD, 98 (31.6%) had undergone a bowel resection, 44 (14.2%) had extra-intestinal manifestations of CD occurring and 112 (46.9%) smoked at diagnosis ; and a significantly increased risk of developing ileal CD  or CD of an inflammatory nature . In addition, a significantly increased risk of having other relatives with IBD and of undergoing bowel resection was observed in individuals with the T allele of rs4988235 .Results from this study suggest that genetic adult-type lactase persistence as evident by the T allele of rs4988235 may increase the risk of developing CD in this New Zealand population.Our findings are in agreement with Juste et al , who repConversely, Büning et al  failed tThe finding that lactase persistence was associated with an increased risk of having a relative with inflammatory bowel disease may reflect the autosomal dominant nature of lactase persistence, whilst the increased risk of CD diagnosis between 17-40 years of age may correspond with the onset of hypolactasia that typically occurs in adulthood in susceptible individuals. The T allele for rs4988235 was also associated with an increased risk of inflammation, having an ileal CD location and bowel resection amongst CD cases. This was an unexpected finding and warrants further investigation to conclusively determine whether lactase persistence may influence the phenotypic expression of CD.As associations between MAP and inflammatory bowel disease have largely been limited to individuals with CD, this study did not evaluate lactase persistence in the ulcerative colitis context. However, the inclusion of this clinical population in future research may provide further insights into the potential association between lactase persistence and inflammatory bowel disease.Whether lactase persistence is an independent risk factor for CD or merely a marker of the likelihood of exposure to the MAP pathogen, found predominantly in milk products, is beyond the scope of this particular study. However epidemiological evidence is conflicting, indicating an urgent need for further, well controlled dietary and genetic case-control studies to distinguish between these two hypotheses.In Japan, Shoda et al  reportedin vivo is more accurately detected [Recent advances in technology have ensured that the presence of MAP detected . These adetected . This madetected .The Zoonotic potential of MAP was discussed in a review by Grant , who repResults from this exploratory study do not prove that MAP exposure is responsible for the development of CD; or that milk products increase risk of the development of CD. However our findings indicate that there may be a complex interaction between exposure to this infectious agent as a consequence of an evolutionary adaptation to ensure tolerance to the milk products that may serve as the medium for its delivery to humans. As the worldwide incidence of CD is rapidly increasing, -29, therFollowing a case-control evaluation of rs4988235 in a New Zealand CD population, we found that lactase persistence as evident by the presence of a T allele was associated with increased CD risk. This finding may relate to the increased exposure to dairy products in individuals with lactase persistence, a food group that has been implicated in the aetiology of CD due to the presence of MAP species in milk. Further research is required to substantiate our findings and to conclusively determine the nature of the observed association between lactase persistence and CD.The authors declare that they have no competing interests.DJN conceived the study and conducted the genotyping of blood samples with WJL. DJN assisted with data analysis, interpretation of data and drafted the manuscript. DYH performed the statistical analyses and contributed to the manuscript. ARM made suggestions to the study and contributed to the manuscript. AGF provided the clinical data and many of the samples obtained. LRF made suggestions for the study and revised the manuscript. LCT revised the manuscript. All authors read and approved the final draft.


Background: Cataract is characterized by light-scattering protein aggregates. The ubiquitin-proteasome system has been proposed a role in proteolytic removal of these protein aggregates. Ubiquitin carboxyl-terminal esterase L1 (UCHL1) is a de-ubiquitinating enzyme withUCHL1 gene has been shown in Parkinson's disease. The current study aimed to examine possible effects on cataract formation.important functions in recycling of ubiquitin. A protective role of the p.S18Y polymorphism of the Methods: Patients with cataract (n = 493) and controls (n = 142) were analyzed for the UCHL1 p.S18Y polymorphism using dynamic allele-specific hybridization.Results: Significant differences were observed in allele and genotype frequencies of the p.S18Y polymorphism between controls and cataract patients, where a positive UCHL1 allele A carrier status was associated with the cataract diagnosis (adjusted OR 1.7 [95% CI = 1.1-2.6] p = 0.02). No significant differences were seen in genotype distribution when stratifying for type of cataract. Nor did the mean age at cataract surgery differ between genotypes.Conclusion: The current study does not support a protective role for the UCHL1 S18Y polymorphism in cataract development, but may instead suggest a disease-promoting effect. UCHL1 gene gained special interest after it had been linked to a family with an autosomal dominant missense mutation (p.I93M) causing Parkinson's disease (PD).UCHL1 polymorphism has been discovered in the course of a search for p.I93M mutants. The p.S18Y variant  shows diminished dimerization and ligase activity.UCHL1 p.S18Y variant is linked to age at onset.UCHL1 genotypes and AD.UCHL1 p.S18Y polymorphism and cataract.Ubiquitin carboxyl-terminal esterase L1 (UCHL1), also known as ubiquitin carboxy-terminal hydrolase and neuron-specific protein gene product 9.5 (PGP 9.5), is one of the most abundant proteins in the brain and therefore used as a sensitive neural marker.tion p.I9M causingAfter informed consent, patients with senile cataract and control individuals were recruited from two ophthalmic clinics in the town of Tartu and the South-Estonian area. The study was approved by the Ethical Commission at the University of Tartu, Estonia. Prior to surgery, the type of cataract was determined using bio-microscopy and ophthalmoscopy. Secondary cataracts were excluded. The case group included 493 cataract patients . The reported age is close to the time of surgery. For control subjects, only individuals above the age of 60 years were included, yielding 142 individuals with a mean age (±SD) of 68 ±5.3 (range 61 to 90 years). Mean age in the cataract group was 72 ±8.7 years (range 47-93 years).UCHL1  p.S18Y, c.53C>A polymorphism (rs5030732) was analyzed using the Dynamic Allele Specific Amplification (DASH) tehnology as described earlier.UCHL1 alleles the probe 5‘GACAGAAACGCACTTGT-Rox3’  was used. The accuracy of the DASH method was verified by DNA sequencing of 15 individuals representing the different UCHL1 genotypes (five of each genotype).The UCHL-1 allele A-carrier status was performed with a binary logistic regression model with diagnosis (cataract versus control) as dependent variable and allele positivity, age and sex as independent variables. Significance was set at P<0.05. SPSS 17.0  was used as statistic software.Primary analyses compared differences between the cataract patients and control subjects regarding age, sex, genotype and allele frequencies using Student's t-test, Fisher's exact test and Pearson's chi-square test. Secondary analysis of UCHL1 allele A-carrier status in UCHL1 allele A-carrier status was significantly higher among cataract patients as compared to the control group (p = 0.015). This association remained after correcting for age and sex, using a binary logistic model (adjusted OR 1.7 [95% CI = 1.1-2.6] p = 0.02), see UCHL1 allele A as compared to controls. This overrepresentation was statistically significant for posterior subcapsular and mixed cataract only , Huntington's (HD), and Parkinson's (PD) diseases. Accordingly, the UPS has been suggested to play a major role in preventing the formation of pathological protein aggregates in these diseases as well.20UCHL1 p.S18Y polymorphism against sporadic PD in different populations,UCHL1 genotype frequencies and its effect on risk of AD is scarce and conflicting.UCHL1 p.S18Y genotype distribution in cataract patients.A number of reports have demonstrated a protective effect of the UCHL1 p.S18Y genotype, there was no significant difference in mean age, neither indicating a protective nor disease-promoting effect. In contrast, the UCHL1 allele A frequency was significantly higher in the cataract group compared to the control group. After stratifying for clinically different types of cataract, significance was lost for nuclear and cortical cataract. If this is a random effect due to sample size or if this reflects pathophysiological differences between cataract subgroups cannot be safely concluded from our data. Nevertheless, these findings may suggest a possible disease-promoting effect and argue against a protective effect of the UCHL1 p.S18Y polymorphism in cataract. However, the associations found were quite weak and argue against any pivotal role for the UCHL1 p.S18Y polymorphism in cataract disease. In addition, a limitation of the present study is that multiple loci or several diseases were not tested.Cataract is a strongly age-dependent disorder; in the Beaver Dam Eye Study, the 5-year cumulative incidence of nuclear cataract increased from 2.9% in persons aged 43 to 54 years at baseline to 40% in those aged 75 or older.UCHL1 gene appears to confer at least a moderate protection in Parkinson's disease.29Given the complexity of the UPS and its essential functions in all organ systems, it is not surprising that it has been implicated in the pathophysiology of a large number of both congenital and acquired diseases and in the process of ageing itself.UCHL1 polymorphism in cataract. Considering the multiple functions of UCHL1 with regard to the UPS, such as recycling of ubiquitin, the processing of ubiquitin precursors and ubiquitin ligase activity,In this study, the p.S18Y variant was underrepre-sented in the control group, hence excluding a protective role of this