12373 results for ""statistically+reactive"+taxa+in+microbial+community"

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• Viral Respiratory Pathogens Genetics

  The overall purpose of this study is to investigate the host genetic factors in response to influenza virus infection, with the focus on influenza vaccination in the first substudy "Adult Influenza Vaccine Genetics" and with the focus on influenza natural infection and other acute respiratory infections (ARIs) in the second substudy "Acute Viral Respiratory Infection Genetics". In the first substudy, healthy adults were enrolled in 2008 (male cohort) and 2010 (female cohort) and immunized with seasonal influenza vaccine. In the second substudy, healthy adults were invited to enroll to be followed for acute respiratory illness through two consecutive influenza seasons 2009-2010 and 2010-2011. Peripheral blood genomic DNA samples were collected from all the subjects, and time-series RNA and serum samples were obtained pre- and post- immunization/infection. Genotyping was carried out on peripheral blood genomic DNA samples using Illumina HumanOmniExpress-12 v1 arrays. Peripheral blood RNA samples obtained at each visit were analyzed using Illumina Human HT-12 (for all the samples) and HiSeq 2000 (for 130 samples in the "Acute Viral Respiratory Infection Genetics" study). Serum specimens were tested using hemagglutination-inhibition (HAI) antibody assay for Influenza H1N1, H3N2, and Influenza B strains. A detailed description of each substudy is provided under their own pages below and via the grouping tool in the right-hand box: phs000635 Adult Influenza Vaccine Genetics phs001031 Acute Viral Respiratory Infection Genetics

  Study phs001030

• Genetic Epidemiology of Refractive Error in the KORA (Kooperative Gesundheitsforschung in der Region Augsburg) Study

  KORA ("Kooperative Gesundheitsforschung in der Region Augsburg" which translates as "Cooperative Health Research in the Region of Augsburg") is a population based study of adults randomly selected from 430,000 inhabitants living in Augsburg and 16 surrounding counties in Germany. The collection was done in 4 separate groups from 1984-2001 (S1-S4). One of the KORA groups, S3/F3, will be utilized for our GWAS because it is the only group with refractive error (RE) measurements. Consequent to informed consent, each of the surveys sampled subjects from ten strata according to age (range 25-74 years) and sex (equal ratio) with a minimum stratum size of > 400 subjects. In the KORA S3 study 4,856 subjects were studied between 1994 and 1995, and 3,006 individuals from S3 returned for follow up between 2003 and 2005 (S3/F3). For this refractive error study, we are including 1,981 subjects from S3/F3 (mean age 55.7, range 35-84). For each subject, eyeglass prescriptions were measured in addition to an evaluation by the Nikon Retinomax. Subjects with predisposing medical conditions, i.e., connective tissue disorders, and ocular conditions i.e., cataract and corneal opacities, that might predispose them to refractive error will not be included for genotyping. Whole genome association genotyping will be performed to determine common alleles that contribute to the variation of the quantitative trait of refractive error.

  Study phs000303

• OncoArray: Follow-up of Ovarian Cancer Genetic Association and Interaction Studies (FOCI)

  The Follow-up of Ovarian Cancer Genetic Association and Interaction Studies (FOCI) was one of five projects funded in 2010 as part of the NCI's Genetic Associations and Mechanisms in Oncology (GAME-ON) initiative (http://epi.grants.cancer.gov/gameon/). FOCI represents a collective effort that builds upon the strengths and history of collaboration inherent in the Ovarian Cancer Association Consortium (OCAC), a multidisciplinary group comprised of epidemiologists, genetic epidemiologists, statistical geneticists, molecular and cell biologists and clinicians that was formed in 2005. The other four funded GAME-ON projects were: the ColoRectal TransdisciplinaryStudy (CORECT), Elucidating Loci Involved in Prostate Cancer Susceptibility (ELLIPSE), Discovery, Biology, and Risk of Inherited Variants in Breast Cancer (DRIVE), and Transdisciplinary Research in Cancer of the Lung (TRICL). As part of our aim to discover, expand, and replicate ovarian cancer susceptibility loci, the GAME-ON projects and other consortia formed the OncoArray network (http://epi.grants.cancer.gov/oncoarray/) to develop and genotype a new custom genotyping array in large numbers of cancer cases and controls (over 400,000 samples) across multiple cancer types. The FOCI data includes over 50,000 ovarian cancer cases and controls genotyped with the Oncoarray at the Center for Inherited Disease Research (CIDR). Genotype calling and quality control procedures were performed under a standardized protocol across the Oncoarray consortium, and over 490,000 SNPs passed QC and are included under this dbGaP submission.

  Study phs001882

• The Bangladesh Environmental Enteric Dysfunction (BEED) Study

  Environmental enteric dysfunction (EED), a sub-acute inflammatory condition of the small intestinal mucosa of unclear etiology, has been associated with a variety of environmental exposures and host factors and is implicated in growth faltering. Linear growth faltering usually occurs within the first two years of life and in most of the cases is irreversible demanding early diagnosis for treatment to be successful. The objectives of 'The Bangladesh Environmental Enteric Dysfunction Study (BEED)' are to investigate role of EED in malnutrition, examine the biology of EED to identify common biological pathways for potential interventions, to validate a system for histological scoring for EED and test the effectiveness of nutritional interventions in improving the growth parameters in children with stunting and or EED. In Bangladesh, participants are recruited from two age groups; a child cohort and a malnourished an adult cohort. In addition, two control groups are recruited for comparison consisting of a) children that are undergoing endoscopy as a part of their clinical care at the University of Virginia Health system (UVAHS) and b) an adult well-nourished control group recruited from the Gastroenterology Outpatient Department of Dhaka Medical College and Hospital in Bangladesh. The description of the study design and procedures of the study can be obtained from Mahfuz M, Das S, Mazumder RN, et al., 2017, PMID: 28801442.

  Study phs001891

• In vitro reconstitution of epigenetic reprogramming in the human germ line

  Epigenetic reprogramming resets parental epigenetic memories and differentiates primordial germ cells (PGCs) into mitotic pro-spermatogonia or oogonia, ensuring sexually dimorphic germ-cell development for totipotency. In vitro reconstitution of epigenetic reprogramming in humans remains a fundamental challenge. Here, we establish a robust strategy for inducing epigenetic reprogramming and differentiation of pluripotent stem cell (PSC)-derived human PGC-like cells (hPGCLCs) into mitotic pro-spermatogonia or oogonia, coupled with their extensive amplification (~>1010-fold). Strikingly, bone morphogenetic protein (BMP) signalling is a key driver of these processes: BMP-driven hPGCLC differentiation involves an attenuation of the mitogen-activated protein kinase/extracellular-regulated kinase (MAPK/ERK) pathway and both de novo and maintenance DNA methyltransferase (DNMT) activities, likely promoting replication-coupled, passive DNA demethylation. On the other hand, hPGCLCs deficient in tens-eleven translocation (TET) 1, an active DNA demethylase abundant in human germ cells, differentiate into extraembryonic cells, including amnion, with de-repression of key genes bearing bivalent promoters; these cells fail to fully activate genes vital for spermatogenesis and oogenesis, with their promoters remaining methylated. Our study elucidates the framework of epigenetic reprogramming in humans, making a fundamental advance in human biology, and through the generation of abundant mitotic pro-spermatogonia and oogonia-like cells, represents a milestone for human in vitro gametogenesis (IVG) research and its potential translation into reproductive medicine.

  Study JGAS000690

• Evolution of DNA repair defects during malignant progression of low-grade gliomas after temozolomide treatment.

  Temozolomide (TMZ) increases the overall survival of patients with glioblastoma (GBM), but its role in the clinical management of diffuse low-grade gliomas (LGG) is still being defined. DNA hypermethylation of the O 6 -methylguanine-DNA methyltransferase (MGMT) promoter is associated with an improved response to TMZ treatment, while inactivation of the DNA mismatch repair (MMR) pathway is associated with therapeutic resistance and TMZ-induced mutagenesis. We previously demonstrated that TMZ treatment of LGG induces driver mutations in the RB and AKT-mTOR pathways, which may drive malignant progression to secondary GBM. To better understand the mechanisms underlying TMZ-induced mutagenesis and malignant progression, we explored the evolution of MGMT methylation and genetic alterations affecting MMR genes in a cohort of 34 treatment-naïve LGGs and their recurrences. Recurrences with TMZ-associated hypermutation had increased MGMT methylation compared to their untreated initial tumors and higher overall MGMT methylation compared to TMZ-treated non-hypermutated recurrences. A TMZ-associated mutation in one or more MMR genes was observed in five out of six TMZ-treated hypermutated recurrences. In two cases, pre-existing heterozygous deletions encompassing MGMT, or an MMR gene, were followed by TMZ-associated mutations in one of the genes of interest. These results suggest that tumor cells with methylated MGMT may undergo positive selection during TMZ treatment in the context of MMR deficiency.

  Study EGAS00001001179

• Mutational Landscape of Grey Zone Lymphoma

  The mutational landscape of grey zone lymphoma (GZL) has not yet been established and differences to related entities are mostly unknown. Here, we studied coding sequence mutations of 50 EBV-negative GZL and 20 polymorphic EBV-positive DLBCL NOS (poly-EBV-L) in comparison to classical Hodgkin lymphoma (cHL), primary mediastinal B cell lymphoma (PMBCL), and diffuse large B cell lymphoma (DLBCL). Paired exomes of 21 GZL and 7 poly-EBV-L cases were analyzed as a discovery cohort followed by targeted sequencing of 217 genes in an extension cohort of 29 GZL and 13 poly-EBV-L cases. GZL cases with thymic niche involvement displayed a mutation profile closely resembling cHL and PMBCL, with SOCS1 (45%), B2M (45%), TNFAIP3 (35%), GNA13 (35%) and NFKBIA (29%) being the most recurrently mutated genes. In contrast, GZL cases without thymic niche involvement (N=18) had a significantly distinct pattern, enriched in mutations related to apoptosis defects (TP53 (39%), BCL2 (28%), BIRC6 (22%)) and depleted in GNA13, XPO1 or NFKB signaling pathway mutations (TNFAIP3, NFKBIE, IKBKB, NFKBIA). Poly-EBV-L cases presented a distinct mutational profile including STAT3, PRKDC mutations and a significantly lower coding-mutation load in comparison to EBV-negative GZL. Our study highlights characteristic mutational patterns in GZL associated with presentation in the thymic niche suggesting a common cell of origin and disease evolution with related anterior mediastinal lymphomas.

  Study EGAS00001004482

• 5- FU treated organoids

  5-Fluorouracil (5-FU) is a chemotherapeutic drug component that is commonly used for the treatment of solid cancers. The anticancer properties of 5-FU have been attributed to interference with nucleotide synthesis and through direct incorporation into the DNA as being a pyrimidine analog. As both mechanisms of action may have a mutational impact on surviving tumor cells, we performed three independent analyses to characterize the genomic consequences of 5-FU treatment: i) in vitro treatment of intestinal organoids with 5-FU followed by whole genome sequencing, ii) genome-wide mutation analyses in tumor samples from 5-FU treated patients with breast or colorectal cancer, and iii) analysis of paired biopsies from patients treated with 5-FU between biopsies. Our results demonstrate that both in vitro and in vivo 5-FU causes a mutational pattern that is dominated by T>G substitutions in a CTT context and with strong resemblance to COSMIC signature 17. Interestingly, this signature is also found in non 5-FU treated patients, most prominently in esophageal tumors, indicating that distinct endogenous and exogenous triggers can converge into highly similar mutational signatures. Furthermore, our results suggest that 5-FU may have adverse mutagenic effects on healthy cells and contributes to genetic variability in surviving cancer cells thereby contributing to tumor evolution.

  Study EGAS00001003592

• Loss of LGR4/GPR48 causes severe neonatal salt-wasting due to disrupted WNT signaling altering adrenal zonation

  Disorders of isolated mineralocorticoid deficiency causing potentially life-threatening salt-wasting crisis early in life have been associated with gene variants of aldosterone biosynthesis or resistance, but in some patients no such variants are found. WNT/β-catenin signaling is crucial for differentiation and maintenance of the aldosterone producing adrenal zona glomerulosa (zG). We describe a highly consanguineous family with multiple perinatal deaths or infants presenting at birth with failure to thrive, severe salt-wasting crises associated with isolated hypoaldosteronism, nail anomalies, short stature, and deafness. Whole exome sequencing revealed a homozygous splice variant in the R-SPONDIN receptor LGR4 gene (c.618-1G>C) regulating WNT signaling. The resulting transcripts affected protein function and stability, and resulted in loss of Wnt/β-catenin signaling in vitro. The impact of LGR4 inactivation was analyzed by adrenal cortex specific ablation of Lgr4, using Lgr4Flox/Flox mated with Sf1:Cre mice. Inactivation of Lgr4 within the adrenal cortex in the mouse model caused decreased WNT signaling, aberrant zonation with deficient zG and reduced aldosterone production. Thus, human LGR4 mutations establish a direct link between LGR4 inactivation and decreased canonical WNT signaling with abnormal zG differentiation and endocrine function. Therefore, variants in WNT signaling and its regulators should systematically be considered in familial hyperreninemic hypoaldosteronism.

  Study EGAS00001006808

• cfDNA dataset from extracelular vesicles and paired non-fractionated samples

  Liquid biopsies contain multiple analytes that can be mined to improve the detection and management of cancer. Beyond cell-free DNA (cfDNA), mutations have been detected in DNA associated with extracellular vesicles (EV-DNA). The genome-wide composition and structure of EV-DNA remains poorly characterized, and whether circulating EVs are enriched in tumor signal compared to unfractionated cfDNA is still unclear. Here, using whole genome sequencing from selected lung cancer patients with a relatively high cfDNA tumor content >5%, we determined that the tumor fraction and heterogeneity are comparable between DNA associated with small (<200 nm) EVs and matched plasma cfDNA. DNA in EV fractions, obtained with standardized size-exclusion chromatography, are comprised of short ~150-180 bp fragments and long >1000 bp fragments that are poor in tumor signal. Other fractions only exhibit short fragments with similar tumor DNA content. The composition in bases at the end of EV-DNA fragments, as well as their fragmentation patterns are similar to total plasma cfDNA. Mitochondrial DNA however is relatively enriched in EV fractions. Our results suggests that cfDNA in plasma may be of dual nature, either bound to proteins (including the nucleosome) but also associated to EVs. cfDNA associated to small EV (including exosomes) is however not preferentially enriched in tumor signal.

  Study EGAS00001006848