1248 results for ""halted+early"+"slower-than-anticipated+enrollment"+hospitalized+oral+adaptive+platform"

in 11.47 milliseconds.

• A spatial human thymus cell atlas mapped to a continuous tissue axis

  T cells develop from circulating precursor cells, which enter the thymus and migrate through specialised sub-compartments that support their maturation and selection. In humans, this process starts in early fetal development and is highly active until thymic involution in adolescence. To map the micro-anatomical underpinnings of this process in pre- and early postnatal stages, we established a novel quantitative morphological framework for the thymus, the Cortico-Medullary Axis, and used it to perform a spatially resolved analysis. By applying this framework to a curated multimodal single-cell atlas, spatial transcriptomics, and high-resolution multiplex imaging data, we demonstrate establishment of the lobular cytokine network, canonical thymocyte trajectories and thymic epithelial cell distributions within the first trimester of fetal development. We pinpoint tissue niches of thymic epithelial cell progenitors and distinct subtypes associated with Hassall’s corpuscles and uncover divergence in the timing of medullary entry between CD4 vs. CD8 T cell lineages. These findings provide a basis for a detailed understanding of T lymphocyte development and are complemented with a holistic toolkit for cross-platform imaging data analysis, annotation, and Organ Axis construction (TissueTag), which can be applied to any tissue.

  Dataset EGAD00001015384

• Idiopathic Pulmonary Fibrosis Network (IPFNet) Sildenafil Trial of Exercise Performance in Idiopathic Pulmonary Fibrosis (IPFNet-STEP-IPF-BioLINCC)

  Data Access NOTE: Please refer to the "Authorized Access" section below for information about how access to the data from this accession differs from many other dbGaP accessions. Objectives: The STEP-IPF study sought to evaluate whether treatment with sildenafil would improve walk distance, dyspnea, and quality of life in participants with advanced idiopathic pulmonary fibrosis (IPF).Background: IPF is a chronic, progressive lung disease of unknown cause that is characterized by the histopathologic pattern of usual interstitial pneumonia. Progression to end-stage respiratory insufficiency and death within 5 years after the onset of symptoms is characteristic. To date, no pharmacologic therapies have definitively been shown to improve survival or quality of life in participants with this disease.Participants with severe IPF have abnormalities of the pulmonary vasculature leading to decreased levels of resting and exercise-induced production of nitric oxide. Since nitric oxide is a potent pulmonary vasodilator, reduced levels are associated with pulmonary vasoconstriction and impaired gas exchange. Sildenafil (Revatio, Pfizer) is a phosphodiesterase-5 inhibitor that stabilizes the second messenger of nitric oxide, cyclic guanosine monophosphate, which leads to pulmonary vasodilatation. Such vasodilatation could improve ventilation–perfusion matching and thus gas exchange in with IPF.Design: STEP-IPF was a double-blind, randomized, placebo-controlled trial of oral sildenafil (20 mg three times daily). Participants meeting eligibility criteria were randomly assigned in a 1:1 ratio to receive sildenafil or matched placebo with the use of a permuted-block design, with stratification according to clinical center. The primary outcome was the presence or absence of an improvement of at least 20% in the 6-minute walk distance at 12 weeks, as compared with baseline. Key secondary outcomes included changes in the 6-minute walk distance, degree of dyspnea, and quality of life.Screening procedures included the taking of a detailed history, a physical examination, spirometry, echocardiography, CT imaging, and measurements of lung volume on plethysmography, carbon monoxide diffusion capacity, and arterial blood gases. Eligible participants returned for an enrollment visit within 6 weeks after screening. All participants received an initial dose of a study drug at this visit and were monitored for 60 minutes for adverse effects. Follow-up visits were scheduled at 1, 6, and 12 weeks. After completion of the 12-week visit, all participants were started on treatment with open-label sildenafil. Visits were scheduled at 13, 18, and 24 weeks; at 28 weeks, serious adverse events and vital status were documented. Testing of the 6-minute walk distance was performed with the use of a standardized protocol at the time of screening and enrollment and at study visits at 6, 12, 18, and 24 weeks. Participants with pulse oxygen saturation below 88% received supplemental oxygen. Conclusions: This study did not show a benefit for sildenafil for the primary outcome. The presence of some positive secondary outcomes creates clinical equipoise for further research. There were small but significant differences in arterial oxygenation, carbon monoxide diffusion capacity, degree of dyspnea, and quality of life favoring the sildenafil group.

  Study phs004085

• Non-Coding Autoimmune Risk Variant Defines Role for ICOS in T Peripheral Helper Cell Development

  Our fine-mapping of 76 non-MHC loci associated with risk for rheumatoid arthritis (RA, 11,475 cases, 15,870 controls) has recently identified rs117701653, a non-coding single nucleotide polymorphism (SNP) in the CTLA4/CD28/ICOS locus, as the variant most likely to modulate RA risk within this region, with the minor allele C showing disease protection compared to the major allele A. We found that this SNP exhibits allele-specific protein binding and transcriptional modulation, further supporting its regulatory nature. Here, we aimed to determine whether the functional non-coding variant rs117701653 modulates the expression of genes within the CD28/CTLA4/ICOS locus. To address this question, we employed low-input RNA sequencing using the Illumina SmartSeq2 platform on resting total CD4+ T cells from the blood of 24 healthy subjects (8 AA, 8 AC, 8 CC) recruited based on genotype from the Mass General Brigham biobank. We performed a targeted cis-eQTL mapping analysis for protein coding genes with transcription start sites (TSS) within a 1MB window of SNP rs117701653. These genes included WDR12, NBEAL1, CYP20A1, ABI2, RAPH1, CD28, CTLA4, ICOS, and PARD3B. Surprisingly, allelic variation at rs117701653 correlated strongly with expression of ICOS. This suggests that individuals carrying the protective allele C at rs117701653 express lower levels of ICOS, implicating ICOS as a plausible target gene influenced by this protective allele. The raw sequence data from the 24 healthy individuals are available through dbGAP. Gene expression matrices have been deposited to GEO accession GSE235868.

  Study phs003448

• Frequent post-treatment monitoring of colorectal cancer using individualized ctDNA validated by multi-regional molecular profiling

  Purpose: Circulating tumor DNA (ctDNA) analysis has been proposed as an approach for prediction of post-treatment patient outcomes. However, whether a single platform will provide optimal information in all patients or alternatively a patient-specific monitoring approach based on assessment of mutations in the primary tumor from that patient remains an urgent question. Experimental Design: We conducted multiregional sequencing of 42 specimens of 14 colorectal tumors (Stage III and more) from 12 patients, including two double cancer cases, to identify the full spectrum of mutational heterogeneity and identify aberrations that could be used to develop personalized ctDNA assays. Results: ?Founder? mutations that occur in all regions of the sample were identified in 12/14 (85.7%) tumors. Subsequent phylogenetic analysis of each tumor showed that 12/14 tumors (85.7%) carried at least one ?truncal? mutation. Most founder and truncal mutations exhibited higher variant allele frequency (VAF) than ?non-founder? and ?branch? mutations. In addition, both founder and truncal mutations were more likely to be detected as ctDNA than non-founder and branch mutations. Synchronized ctDNA dynamics of multiple mutations suggested those mutations from the same clonal origin. For 10/12 patients (83.3%) with nearly 1,000 days of post-operative observation, the validity of frequent personalized ctDNA monitoring was confirmed in terms of early relapse prediction, treatment efficacy, and non-relapse corroboration. Conclusions: Personalized ctDNA monitoring based on aberrations with a high VAF in the primary tumor site should be explored in larger prospective clinical trials to determine the full clinical validity.

  Study JGAS000243

• Single-cell DNA amplicon sequencing reveals clonal heterogeneity and evolution in T-cell acute lymphoblastic leukemia

  T-cell acute lymphoblastic leukemia (T-ALL) is an aggressive leukemia that is most frequent in children and is characterized by the presence of few chromosomal rearrangements and 10 to 20 somatic mutations in protein-coding regions at diagnosis. The majority of T-ALL cases harbor activating mutations in NOTCH1 together with mutations in genes implicated in kinase signaling, transcriptional regulation or protein translation. To obtain more insight in the level of clonal heterogeneity at diagnosis and during treatment, we used single-cell targeted DNA sequencing with the Tapestri platform. We designed a custom ALL panel and obtained accurate single-nucleotide variant and small insertion-deletion mutation calling for 305 amplicons covering 110 genes in about 4400 cells per sample and time point. A total of 108,188 cells were analyzed for 25 samples of 8 T-ALL patients. We typically observed a major clone at diagnosis (>35% of the cells) accompanied by several minor clones of which some were less than 1% of the total number of cells. Four patients had >2 NOTCH1 mutations some of which present in minor clones, indicating a strong pressure to acquire NOTCH1 mutations in developing T-ALL cells. By analyzing longitudinal samples, we detected the presence and clonal nature of residual leukemic cells as well as clones with a minor presence at diagnosis that evolved to clinically relevant major clones at later disease stages. Single-cell DNA amplicon sequencing is a sensitive assay to detect clonal architecture and evolution in T-ALL.

  Study EGAS00001004440

• Capturing disease severity in LIS1-lissencephaly reveals proteostasis dysregulation in patient-derived forebrain organoids

  Lissencephaly is a developmental cortical malformation characterized by reduced to absent gyri and a disorganized cortex, often leading to severe impairments in affected individuals and a reduced life expectancy. Heterozygous mutations in the LIS1 gene, encoding a regulator of the microtubule motor dynein, cause lissencephaly with different clinical severities. While the clinical disease spectrum correlates with the degree of lissencephaly, location and type of mutation may not. We leveraged forebrain-type organoids from LIS1-lissencephaly patients, diagnosed with mild, moderate or severe lissencephaly to investigate, in a cytoarchitecture and multi-omics approach, how the severity degree in patients might relate to specific mutations in the LIS1 gene. We questioned which processes during cortical development might be differentially affected by severity grade, and whether they could be pharmacologically targeted. We found alterations in neurodevelopment often with a severity-dependent gradient. Specifically, we identified alterations of the cytoarchitecture, progenitor cell homeostasis and neurogenesis. Particularly important disease-linked molecular mechanisms were microtubule destabilization, WNT-signaling, and perturbed cadherin- and unfolded protein-binding. Some mechanisms exhibited a severity-dependent gradient, or were specific to a severe grade. We present strategies to reverse phenotypic changes in LIS1-patient organoids, and an in silico approach with therapeutic potential. Thus, we show that different LIS1-severity grades can be recapitulated in vitro, that there is a direct link between the phenotype and genotype, that organoid-based disease modeling can identify molecular underpinnings of malformations of cortical development and that organoids provide a valid platform to develop and test therapeutic strategies.

  Study EGAS00001008227

• The University of Hong Kong Intestinal Metaplasia Organoids Study

  Background: Gastric intestinal metaplasia (IM) is a pre-cancerous stage spanning a morphological spectrum that is poorly represented by human cell line models. Objective: We aim to establish and characterize human IM cell models to better understand IM progression along the cancer spectrum. Design: A large human gastric IM organoid (IMO) cohort (n=28), their clonal derivatives and normal gastric organoids (n=42) for comparison were established. Comprehensive multi-omics profiling and functional characterization were performed. Results: Single-cell transcriptomes revealed IMO cells spanning a spectrum from hybrid gastric/intestinal to advanced intestinal differentiation. Their lineage trajectories connected different cycling and quiescent stem and progenitors, highlighting differences in gastric to IM transition and the potential origin of IM from STMN1 cycling isthmus stem cells. Hybrid IMOs showed impaired differentiation potential, high lineage plasticity beyond gastric or intestinal fates, and reactivation of a fetal gene program. Cell populations in gastric IM and cancer tissues were highly similar to those derived from IMOs and exhibited a fetal signature. Genomically, IMOs showed elevated mutation burden, frequent chromosome 20 gain, and epigenetic de-regulation of many intestinal and gastric genes. Functionally, IMOs were FGF10 independent and showed downregulated FGFR2. Several IMOs exhibited a cell-matrix adhesion independent (CMi) subpopulation that displayed chromosome 20 gain but lacked key cancer driver mutations, potentially representing the earliest neoplastic precursor of IM-induced gastric cancer. Conclusions: Overall, our IM organoid biobank captured the heterogeneous nature of IM, revealing mechanistic insights on IM pathogenesis and progression, offering an ideal platform for studying early gastric neoplastic transformation and chemoprevention.

  Study EGAS00001007899

• Next Generation Sequencing platform for targeted Personalized Therapy of Leukemia - Acute myeloid leukemia

  The advent of high-throughput next generation sequencing (NGS) technologies that are revolutionizing genomics and transcriptomics by providing a single base resolution tool for a unified deep analysis of diseases complexity allows a fast and cost-efficient fine-scale assessment of the genetic variability hidden within cohorts of patients affected by the same leukemia. That being so, by potentially highlighting inter-individual differences that may play a role in the differential success of diverse therapeutic interventions, they promise to be crucial for selecting the most appropriate medical treatments. The project aims at the identification of novel prognostic biomarkers for acute myeloid leukemia (AML) and studied the molecular differences between aneuploid and euploid AML.

  Study EGAS00001005464

• Whole exome sequencing of a representative cohort of AML

  The Genomic DNA Clean & Concentrator kit (ZYMO Research) was used to remove EDTA from the DNA samples. Sample libraries were prepared using 100 ng of input according to the KAPA HyperPlus Kit (Roche) using Unique Dual Index adapters (Integrated DNA Technologies, Inc.). Exomes were captured using the SeqCap EZ MedExome (Roche Nimblegen) according to SeqCap EZ HyperCap Library v1.0 Guide (Roche) with the xGen Universal blockers – TS Mix (Integrated DNA Technologies, Inc.). The amplified captured sample libraries were paired-end sequenced (2x100 bp) on the Novaseq 6000 platform (Illumina) and aligned to the hg19 reference genome using the Burrows-Wheeler Aligner (BWA)3, v0.7.15-r1140.

  Dataset EGAD00001007580

• Targeted de novo phasing and long-range assembly by template mutagenesis

  Long-range sequencing with low error rate has been challenging. Sequence assembly and phasing usually require a high-quality reference genome for mapping, so working on highly-variable genomic regions or regions with no reference genome information would be difficult. In this study, we describe novel bench protocols and algorithms to obtain ultra-low-error-rate haplotype-phased sequence assemblies of regions 10 KB in length using a short-read sequencing platform that simultaneously solves the above two problems. We accomplish this by imprinting each template strand from a target region with a dense and unique mutation pattern. The mutation process randomly and independently converts ~50% of cytosines to uracils. Short-read sequencing libraries are made from both mutated and unmutated templates. A conservative de Bruijn graph approach seeds an assembly of the mutated templates, which we then extend by mapping paired-end reads. We next partition the template assemblies into two or more haplotypes after using the unmutated sequence library to recover almost all of the mutated bases. The final haplotype is assembled and corrected for residual template mutations and PCR errors. We obtain per-base-error rates below 10 9. We apply this method to a human family, correctly assembling and phasing three genomic intervals, including the highly polymorphic HLA-B gene.

  Dataset EGAD00001008444