76 research outputs found

    Genetic variants of CYP3A5, CYP2D6, SULT1A1, UGT2B15 and tamoxifen response in postmenopausal patients with breast cancer

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    INTRODUCTION: Tamoxifen therapy reduces the risk of recurrence and prolongs the survival of oestrogen-receptor-positive patients with breast cancer. Even if most patients benefit from tamoxifen, many breast tumours either fail to respond or become resistant. Because tamoxifen is extensively metabolised by polymorphic enzymes, one proposed mechanism underlying the resistance is altered metabolism. In the present study we investigated the prognostic and/or predictive value of functional polymorphisms in cytochrome P450 3A5 CYP3A5 (*3), CYP2D6 (*4), sulphotransferase 1A1 (SULT1A1; *2) and UDP-glucuronosyltransferase 2B15 (UGT2B15; *2) in tamoxifen-treated patients with breast cancer. METHODS: In all, 677 tamoxifen-treated postmenopausal patients with breast cancer, of whom 238 were randomised to either 2 or 5 years of tamoxifen, were genotyped by using PCR with restriction fragment length polymorphism or PCR with denaturing high-performance liquid chromatography. RESULTS: The prognostic evaluation performed in the total population revealed a significantly better disease-free survival in patients homozygous for CYP2D6*4. For CYP3A5, SULT1A1 and UGT2B15 no prognostic significance was observed. In the randomised group we found that for CYP3A5, homozygous carriers of the *3 allele tended to have an increased risk of recurrence when treated for 2 years with tamoxifen, although this was not statistically significant (hazard ratio (HR) = 2.84, 95% confidence interval (CI) = 0.68 to 11.99, P = 0.15). In the group randomised to 5 years' tamoxifen the survival pattern shifted towards a significantly improved recurrence-free survival (RFS) among CYP3A5*3-homozygous patients (HR = 0.20, 95% CI = 0.07 to 0.55, P = 0.002). No reliable differences could be seen between treatment duration and the genotypes of CYP2D6, SULT1A1 or UGT2B15. The significantly improved RFS with prolonged tamoxifen treatment in CYP3A5*3 homozygotes was also seen in a multivariate Cox model (HR = 0.13, CI = 0.02 to 0.86, P = 0.03), whereas no differences could be seen for CYP2D6, SULT1A1 and UGT2B15. CONCLUSION: The metabolism of tamoxifen is complex and the mechanisms responsible for the resistance are unlikely to be explained by a single polymorphism; instead it is a combination of several mechanisms. However, the present data suggest that genetic variation in CYP3A5 may predict response to tamoxifen therapy

    Alteration of the phospho- or neutral lipid content and fatty acid composition in Listeria monocytogenes due to acid adaptation mechanisms for hydrochloric, acetic and lactic acids at pH 5.5 or benzoic acid at neutral pH

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    This study provides a first approach to observe the effects on Listeria monocytogenes of cellular exposure to acid stress at low or neutral pH, notably how phospho- or neutral lipids are involved in this mechanism, besides the fatty acid profile alteration. A thorough investigation of the composition of polar and neutral lipids from L. monocytogenes grown at pH 5.5 in presence of hydrochloric, acetic and lactic acids, or at neutral pH 7.3 in presence of benzoic acid, is described relative to cells grown in acid-free medium. The results showed that only low pH values enhance the antimicrobial activity of an acid. We suggest that, irrespective of pH, the acid adaptation response will lead to a similar alteration in fatty acid composition [decreasing the ratio of branched chain/saturated straight fatty acids of total lipids], mainly originating from the neutral lipid class of adapted cultures. Acid adaptation in L. monocytogenes was correlated with a decrease in total lipid phosphorus and, with the exception of cells adapted to benzoic acid, this change in the amount of phosphorus reflected a higher content of the neutral lipid class. Upon acetic or benzoic acid stress the lipid phosphorus proportion was analysed in the main phospholipids present: cardiolipin, phosphatidylglycerol, phosphoaminolipid and phosphatidylinositol. Interestingly only benzoic acid had a dramatic effect on the relative quantities of these four phospholipids

    No association of alcohol use and the risk of ulcerative colitis or Crohn’s disease: data from a European Prospective cohort study (EPIC)

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    Background The role of long -term alcohol consumption for the risk of developing ulcerative colitis (UC) and Crohn’s disease (CD) is unclear. Aim s For the first time, t o prospectively assess the role of pre -disease alcohol consumption o n the risk of developing UC or CD. Methods Nested within the European Prospective Investigation into Cancer and Nutrition (EPIC - IBD ), incident UC and CD cases and ma tched controls where included. At recruitment, participants completed validated food frequency and lifestyle questionnaires. Alcohol consumption was classified as either: non -use, former, light ( ≤ 0.5 and 1 drink/week), below the recommended limits (BRL) ( ≤ 1 and 2 drinks/day), moderate ( ≤ 2.5 and 5 drinks/day) , or heavy use (>2.5 and >5 drinks/ day) for women and men, respectively ; and was expressed as consumption at enrolment and during lifetime. Conditional logistic regression was applied adjusting for smoking and education , taking light users as the 3 Abstract Background The role of long -term alcohol consumption for the risk of developing ulcerative colitis (UC) and Crohn’s disease (CD) is unclear. Aim s For the first time, t o prospectively assess the role of pre -disease alcohol consumption o n the risk of developing UC or CD. Methods Nested within the European Prospective Investigation into Cancer and Nutrition (EPIC - IBD ), incident UC and CD cases and ma tched controls where included. At recruitment, participants completed validated food frequency and lifestyle questionnaires. Alcohol consumption was classified as either: non -use, former, light ( ≤ 0.5 and 1 drink/week), below the recommended limits (BRL) ( ≤ 1 and 2 drinks/day), moderate ( ≤ 2.5 and 5 drinks/day) , or heavy use (>2.5 and >5 drinks/ day) for women and men, respectively ; and was expressed as consumption at enrolment and during lifetime. Conditional logistic regression was applied adjusting for smoking and education , taking light users as the reference. Results Out of 262,451 participants in 6 countries, 198 UC incident cases/792 controls and 84 CD cases/336 controls were included. At enrolment, 8%/27%/3 2%/2 3%/1 1% UC cases and 7%/2 9%/4 0%/19%/ 5% C D cases were: non -users, light, BRL, moderate and heavy users, respectively. The corresponding figures for lifetime non -use, former, light, BRL, moderate and heavy use were : 3%/5%/2 3%/44%/19%/6% and 5%/2%/25%/44%/23 %/1% for UC and CD cases , respectively. There were no associations between any categories of alcohol consumption and risk of UC or CD in the una djusted and adjusted odds ratios . Conclusion There was no evidence of association s between alcohol use and the odds of developing either UC or CD

    Association between i.v. thrombolysis volume and door-to-needle times in acute ischemic stroke

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    Centralization of intravenous thrombolysis (IVT) for acute ischemic stroke in high-volume centers is believed to improve the door-to-needle times (DNT), but limited data support this assumption. We examined the association between DNT and IVT volume in a large Dutch province. We identified consecutive patients treated with IVT between January 2009 and 2013. Based on annualized IVT volume, hospitals were categorized as low-volume (≤ 24), medium-volume (25-49) or high-volume (≥ 50). In logistic regression analysis, low-volume hospitals were used as reference category. Of 17,332 stroke patients from 11 participating hospitals, 1962 received IVT (11.3 %). We excluded 140 patients because of unknown DNT (n = 86) or in-hospital stroke (n = 54). There were two low-volume (total 101 patients), five medium-volume (747 patients) and four high-volume hospitals (974 patients). Median DNT was shorter in high-volume hospitals (30 min) than in medium-volume (42 min, p < 0.001) and low-volume hospitals (38 min, p < 0.001). Patients admitted to high-volume hospitals had a higher chance of DNT < 30 min (adjusted OR 3.13, 95 % CI 1.70-5.75), lower risk of symptomatic intracerebral hemorrhage (adjusted OR 0.39, 95 % CI 0.16-0.92), and a lower mortality risk (adjusted OR 0.45, 95 % CI 0.21-1.01), compared to low-volume centers. There was no difference in DNT between low- and medium-volume hospitals. Onset-to-needle times (ONT) did not differ between the groups. Hospitals in this Dutch province generally achieved short DNTs. Despite this overall good performance, higher IVT volumes were associated with shorter DNTs and lower complication risks. The ONT was not associated with IVT volum

    An Agent-Based Model of a Hepatic Inflammatory Response to Salmonella: A Computational Study under a Large Set of Experimental Data

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    Citation: Shi, Z. Z., Chapes, S. K., Ben-Arieh, D., & Wu, C. H. (2016). An Agent-Based Model of a Hepatic Inflammatory Response to Salmonella: A Computational Study under a Large Set of Experimental Data. Plos One, 11(8), 39. doi:10.1371/journal.pone.0161131We present an agent-based model (ABM) to simulate a hepatic inflammatory response (HIR) in a mouse infected by Salmonella that sometimes progressed to problematic proportions, known as "sepsis". Based on over 200 published studies, this ABM describes interactions among 21 cells or cytokines and incorporates 226 experimental data sets and/or data estimates from those reports to simulate a mouse HIR in silico. Our simulated results reproduced dynamic patterns of HIR reported in the literature. As shown in vivo, our model also demonstrated that sepsis was highly related to the initial Salmonella dose and the presence of components of the adaptive immune system. We determined that high mobility group box-1, C-reactive protein, and the interleukin-10: tumor necrosis factor-a ratio, and CD4+ T cell: CD8+ T cell ratio, all recognized as biomarkers during HIR, significantly correlated with outcomes of HIR. During therapy-directed silico simulations, our results demonstrated that anti-agent intervention impacted the survival rates of septic individuals in a time-dependent manner. By specifying the infected species, source of infection, and site of infection, this ABM enabled us to reproduce the kinetics of several essential indicators during a HIR, observe distinct dynamic patterns that are manifested during HIR, and allowed us to test proposed therapy-directed treatments. Although limitation still exists, this ABM is a step forward because it links underlying biological processes to computational simulation and was validated through a series of comparisons between the simulated results and experimental studies

    Novel loci for childhood body mass index and shared heritability with adult cardiometabolic traits

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    The genetic background of childhood body mass index (BMI), and the extent to which the well-known associations of childhood BMI with adult diseases are explained by shared genetic factors, are largely unknown. We performed a genome-wide association study meta-analysis of BMI in 61,111 children aged between 2 and 10 years. Twenty-five independent loci reached genome-wide significance in the combined discovery and replication analyses. Two of these, located nearNEDD4LandSLC45A3, have not previously been reported in relation to either childhood or adult BMI. Positive genetic correlations of childhood BMI with birth weight and adult BMI, waist-to-hip ratio, diastolic blood pressure and type 2 diabetes were detected (R(g)ranging from 0.11 to 0.76, P-values <0.002). A negative genetic correlation of childhood BMI with age at menarche was observed. Our results suggest that the biological processes underlying childhood BMI largely, but not completely, overlap with those underlying adult BMI. The well-known observational associations of BMI in childhood with cardio-metabolic diseases in adulthood may reflect partial genetic overlap, but in light of previous evidence, it is also likely that they are explained through phenotypic continuity of BMI from childhood into adulthood.Author summary Although twin studies have shown that body mass index (BMI) is highly heritable, many common genetic variants involved in the development of BMI have not yet been identified, especially in children. We studied associations of more than 40 million genetic variants with childhood BMI in 61,111 children aged between 2 and 10 years. We identified 25 genetic variants that were associated with childhood BMI. Two of these have not been implicated for BMI previously, located close to the genesNEDD4LandSLC45A3. We also show that the genetic background of childhood BMI overlaps with that of birth weight, adult BMI, waist-to-hip-ratio, diastolic blood pressure, type 2 diabetes, and age at menarche. Our results suggest that the biological processes underlying childhood BMI largely overlap with those underlying adult BMI. However, the overlap is not complete. Additionally, the genetic backgrounds of childhood BMI and other cardio-metabolic phenotypes are overlapping. This may mean that the associations of childhood BMI and later cardio-metabolic outcomes are partially explained by shared genetics, but it could also be explained by the strong association of childhood BMI with adult BMI

    The importance of the altricial – precocial spectrum for social complexity in mammals and birds:A review

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    Various types of long-term stable relationships that individuals uphold, including cooperation and competition between group members, define social complexity in vertebrates. Numerous life history, physiological and cognitive traits have been shown to affect, or to be affected by, such social relationships. As such, differences in developmental modes, i.e. the ‘altricial-precocial’ spectrum, may play an important role in understanding the interspecific variation in occurrence of social interactions, but to what extent this is the case is unclear because the role of the developmental mode has not been studied directly in across-species studies of sociality. In other words, although there are studies on the effects of developmental mode on brain size, on the effects of brain size on cognition, and on the effects of cognition on social complexity, there are no studies directly investigating the link between developmental mode and social complexity. This is surprising because developmental differences play a significant role in the evolution of, for example, brain size, which is in turn considered an essential building block with respect to social complexity. Here, we compiled an overview of studies on various aspects of the complexity of social systems in altricial and precocial mammals and birds. Although systematic studies are scarce and do not allow for a quantitative comparison, we show that several forms of social relationships and cognitive abilities occur in species along the entire developmental spectrum. Based on the existing evidence it seems that differences in developmental modes play a minor role in whether or not individuals or species are able to meet the cognitive capabilities and requirements for maintaining complex social relationships. Given the scarcity of comparative studies and potential subtle differences, however, we suggest that future studies should consider developmental differences to determine whether our finding is general or whether some of the vast variation in social complexity across species can be explained by developmental mode. This would allow a more detailed assessment of the relative importance of developmental mode in the evolution of vertebrate social systems
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