40 research outputs found

    A kinetic study of the formation of smectic phases in novel liquid crystal ionogens

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    [EN] A multi-rate non-isothermal kinetic analysis of the isotropic-melt to liquid crystalline phase transition of novel liquid crystalline ionogenic copolymers, LCIs, the 10-(4-methoxyazobenzene-4'-oxy)decyl methacrylate]-co-2-(acrylamido-2-methyl-1-propanesulfonic acid)s, 10-MeOAzB/AMPS, copolymers, has been performed by means of calorimetric experiments. An analytical methodology which includes the study of the phase transition rate parameter, the determination of the activation energies by using Kissinger and Flynn-Wall-Ozawa models, and the study of the phase transition kinetics by the use of the Avrami theory, has been applied. The formation of the mesophases from the isotropic state occurred close to thermodynamic equilibrium. The results evidence the presence of several individual processes in the formation of liquid crystalline phases from the melt and a strong dependence of phase transition rates and activation energies with acid contents. A decrease in the phase transition rate, related to a decrease in the overall change of the transition entropy, has been observed. The final inhibition of the liquid crystal (LC) behaviour is ascribed to an exponential increase in the activation energy of the phase transition, promoted by strong acid aggregation. An optimum composition of the 10-MeOAzB/AMPS copolymers to achieve the dual characteristics of LCIs (ionogenic and liquid crystalline behaviour) requires acid concentrations capable of promoting structure-forming effects on the LC phases and the evolution of phase separated morphologies.The authors would like to acknowledge the Spanish Ministry of Science and Innovation, through the Research Projects ENE2007-67584-C03, UPOVCE-3E-013, ENE2011-28735-C02-01, IT-2009-0074 and three FPI and FPU predoctoral grants, and the financial support of the Generalitat Valenciana, through the Grisolia and Forteza programs and the ACOMP/2011/189 program. The Vice-rectorate for Research of UPV is also thanked for additional support through the PAID 05-09-4331, PAID-05-11/2806, and PAID 06-11-2037 projects.Martinez-Felipe, A.; Badia, J.; Santonja Blasco, L.; Imrie, C.; Ribes Greus, MD. (2013). A kinetic study of the formation of smectic phases in novel liquid crystal ionogens. European Polymer Journal. 49(6):1553-1563. https://doi.org/10.116/j.eurpolymj.2013.01.021S1553156349

    Antiinflammatory activity of Cayaponia podantha crude extract and fractions

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    The effects of the crude extract and fractions of Cayaponia podantha (Cp) on experimental inflammation models were investigated. Paw edema induced by carrageenan (Cg) and peritonitis induced by Cg, LPS, and LTB4 were evaluated in rats treated orally with different doses of extract. Croton oil (CO) induced ear edema and the determination of MPO activity were evaluated in mice. Crude Cp extract and hexane (HF), ethyl-acetate (AF) and hidromethanol (MF) fractions were topically applied immediately after the application of the CO. Four hours after Cg injection, animals treated with crude extract (250 and 500 mg/kg) displayed significantly decreased paw edema. The Cp extract (250, 500, and 750 mg/kg) decreased vascular permeability and leukocyte migration in the peritonitis model in the 3rd h after induction of the inflammatory reaction. Furthermore, the 500 mg/kg dose of Cp extract also reduced LPS- and LTB4-induced migration. Crude extract and hexane and ethyl-acetate fractions (5.0 mg) significantly inhibited ear edema and MPO activity. Our results showed that Cp crude extract and fractions exhibited anti-inflammatory effects when they are administered orally or topically in animals.Colegio de Farmacéuticos de la Provincia de Buenos Aire

    A combined linkage, microarray and exome analysis suggests MAP3K11 as a candidate gene for left ventricular hypertrophy

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    Background: Electrocardiographic measures of left ventricular hypertrophy (LVH) are used as predictors of cardiovascular risk. We combined linkage and association analyses to discover novel rare genetic variants involved in three such measures and two principal components derived from them. Methods: The study was conducted among participants from the Erasmus Rucphen Family Study (ERF), a Dutch family-based sample from the southwestern Netherlands. Variance components linkage analyses were performed using Merlin. Regions of interest (LOD > 1.9) were fine-mapped using microarray and exome sequence data. Results: We observed one significant LOD score for the second principal component on chromosome 15 (LOD score = 3.01) and 12 suggestive LOD scores. Several loci contained variants identified in GWAS for these traits; however, these did not explain the linkage peaks, nor did other common variants. Exome sequence data identified two associated variants after multiple testing corrections were applied. Conclusions: We did not find common SNPs explaining these linkage signals. Exome sequencing uncovered a relatively rare variant in MAPK3K11 on chromosome 11 (MAF = 0.01) that helped account for the suggestive linkage peak observed for the first principal component. Conditional analysis revealed a drop in LOD from 2.01 to 0.88 for MAP3K11, suggesting that this variant may partially explain the linkage signal at this chromosomal location. MAP3K11 is related to the JNK pathway and is a pro-apoptotic kinase that plays an important role in the induction of cardiomyocyte apoptosis in various pathologies, including LVH

    Distribution patterns of tau pathology in progressive supranuclear palsy

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    Progressive supranuclear palsy (PSP) is a 4R-tauopathy predominated by subcortical pathology in neurons, astrocytes, and oligodendroglia associated with various clinical phenotypes. In the present international study, we addressed the question of whether or not sequential distribution patterns can be recognized for PSP pathology. We evaluated heat maps and distribution patterns of neuronal, astroglial, and oligodendroglial tau pathologies and their combinations in different clinical subtypes of PSP in postmortem brains. W

    Associations between infant fungal and bacterial dysbiosis and childhood atopic wheeze in a nonindustrialized setting.

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    BACKGROUND: Asthma is the most prevalent chronic disease of childhood. Recently, we identified a critical window early in the life of both mice and Canadian infants during which gut microbial changes (dysbiosis) affect asthma development. Given geographic differences in human gut microbiota worldwide, we studied the effects of gut microbial dysbiosis on atopic wheeze in a population living in a distinct developing world environment. OBJECTIVE: We sought to determine whether microbial alterations in early infancy are associated with the development of atopic wheeze in a nonindustrialized setting. METHODS: We conducted a case-control study nested within a birth cohort from rural Ecuador in which we identified 27 children with atopic wheeze and 70 healthy control subjects at 5 years of age. We analyzed bacterial and eukaryotic gut microbiota in stool samples collected at 3 months of age using 16S and 18S sequencing. Bacterial metagenomes were predicted from 16S rRNA data by using Phylogenetic Investigation of Communities by Reconstruction of Unobserved States and categorized by function with Kyoto Encyclopedia of Genes and Genomes ontology. Concentrations of fecal short-chain fatty acids were determined by using gas chromatography. RESULTS: As previously observed in Canadian infants, microbial dysbiosis at 3 months of age was associated with later development of atopic wheeze. However, the dysbiosis in Ecuadorian babies involved different bacterial taxa, was more pronounced, and also involved several fungal taxa. Predicted metagenomic analysis emphasized significant dysbiosis-associated differences in genes involved in carbohydrate and taurine metabolism. Levels of the fecal short-chain fatty acids acetate and caproate were reduced and increased, respectively, in the 3-month stool samples of children who went on to have atopic wheeze. CONCLUSIONS: Our findings support the importance of fungal and bacterial microbiota during the first 100 days of life on the development of atopic wheeze and provide additional support for considering modulation of the gut microbiome as a primary asthma prevention strategy

    Global trends of hand and wrist trauma: A systematic analysis of fracture and digit amputation using the Global Burden of Disease 2017 Study

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    Background: As global rates of mortality decrease, rates of non-fatal injury have increased, particularly in low Socio-demographic Index (SDI) nations. We hypothesised this global pattern of non-fatal injury would be demonstrated in regard to bony hand and wrist trauma over the 27-year study period. Methods: The Global Burden of Diseases, Injuries, and Risk Factors Study 2017 was used to estimate prevalence, age-standardised incidence and years lived with disability for hand trauma in 195 countries from 1990 to 2017. Individual injuries included hand and wrist fractures, thumb amputations and non-thumb digit amputations. Results: The global incidence of hand trauma has only modestly decreased since 1990. In 2017, t

    Common Genetic Variation And Age at Onset Of Anorexia Nervosa

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    Background Genetics and biology may influence the age at onset of anorexia nervosa (AN). The aims of this study were to determine whether common genetic variation contributes to AN age at onset and to investigate the genetic associations between age at onset of AN and age at menarche. Methods A secondary analysis of the Psychiatric Genomics Consortium genome-wide association study (GWAS) of AN was performed which included 9,335 cases and 31,981 screened controls, all from European ancestries. We conducted GWASs of age at onset, early-onset AN (< 13 years), and typical-onset AN, and genetic correlation, genetic risk score, and Mendelian randomization analyses. Results Two loci were genome-wide significant in the typical-onset AN GWAS. Heritability estimates (SNP-h2) were 0.01-0.04 for age at onset, 0.16-0.25 for early-onset AN, and 0.17-0.25 for typical-onset AN. Early- and typical-onset AN showed distinct genetic correlation patterns with putative risk factors for AN. Specifically, early-onset AN was significantly genetically correlated with younger age at menarche, and typical-onset AN was significantly negatively genetically correlated with anthropometric traits. Genetic risk scores for age at onset and early-onset AN estimated from independent GWASs significantly predicted age at onset. Mendelian randomization analysis suggested a causal link between younger age at menarche and early-onset AN. Conclusions Our results provide evidence consistent with a common variant genetic basis for age at onset and implicate biological pathways regulating menarche and reproduction.Peer reviewe

    Shared genetic risk between eating disorder- and substance-use-related phenotypes:Evidence from genome-wide association studies

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    First published: 16 February 202

    Assessing associations between the AURKAHMMR-TPX2-TUBG1 functional module and breast cancer risk in BRCA1/2 mutation carriers

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    While interplay between BRCA1 and AURKA-RHAMM-TPX2-TUBG1 regulates mammary epithelial polarization, common genetic variation in HMMR (gene product RHAMM) may be associated with risk of breast cancer in BRCA1 mutation carriers. Following on these observations, we further assessed the link between the AURKA-HMMR-TPX2-TUBG1 functional module and risk of breast cancer in BRCA1 or BRCA2 mutation carriers. Forty-one single nucleotide polymorphisms (SNPs) were genotyped in 15,252 BRCA1 and 8,211 BRCA2 mutation carriers and subsequently analyzed using a retrospective likelihood appr

    New insights into the genetic etiology of Alzheimer's disease and related dementias

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    Characterization of the genetic landscape of Alzheimer's disease (AD) and related dementias (ADD) provides a unique opportunity for a better understanding of the associated pathophysiological processes. We performed a two-stage genome-wide association study totaling 111,326 clinically diagnosed/'proxy' AD cases and 677,663 controls. We found 75 risk loci, of which 42 were new at the time of analysis. Pathway enrichment analyses confirmed the involvement of amyloid/tau pathways and highlighted microglia implication. Gene prioritization in the new loci identified 31 genes that were suggestive of new genetically associated processes, including the tumor necrosis factor alpha pathway through the linear ubiquitin chain assembly complex. We also built a new genetic risk score associated with the risk of future AD/dementia or progression from mild cognitive impairment to AD/dementia. The improvement in prediction led to a 1.6- to 1.9-fold increase in AD risk from the lowest to the highest decile, in addition to effects of age and the APOE ε4 allele
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