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163
result(s) for
"Santiago, Rebecca A."
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Scalable whole-exome sequencing of cell-free DNA reveals high concordance with metastatic tumors
by
Freeman, Samuel S.
,
Lin, Nancy U.
,
Rosenberg, Mara
in
631/67/69
,
692/4028/67
,
Antigens, Neoplasm - genetics
2017
Whole-exome sequencing of cell-free DNA (cfDNA) could enable comprehensive profiling of tumors from blood but the genome-wide concordance between cfDNA and tumor biopsies is uncertain. Here we report ichorCNA, software that quantifies tumor content in cfDNA from 0.1× coverage whole-genome sequencing data without prior knowledge of tumor mutations. We apply ichorCNA to 1439 blood samples from 520 patients with metastatic prostate or breast cancers. In the earliest tested sample for each patient, 34% of patients have ≥10% tumor-derived cfDNA, sufficient for standard coverage whole-exome sequencing. Using whole-exome sequencing, we validate the concordance of clonal somatic mutations (88%), copy number alterations (80%), mutational signatures, and neoantigens between cfDNA and matched tumor biopsies from 41 patients with ≥10% cfDNA tumor content. In summary, we provide methods to identify patients eligible for comprehensive cfDNA profiling, revealing its applicability to many patients, and demonstrate high concordance of cfDNA and metastatic tumor whole-exome sequencing.
Identifying the mutational landscape of tumours from cell-free DNA in the blood could help diagnostics in cancer. Here, the authors present ichorCNA, software that quantifies tumour content in cell free DNA, and they demonstrate that cell-free DNA whole-exome sequencing is concordant with metastatic tumour whole-exome sequencing.
Journal Article
Learning representations for image-based profiling of perturbations
by
Senft, Rebecca A.
,
Smith, Matthew
,
McQuin, Claire
in
631/114/1305
,
631/114/1564
,
631/154/1435/2417
2024
Measuring the phenotypic effect of treatments on cells through imaging assays is an efficient and powerful way of studying cell biology, and requires computational methods for transforming images into quantitative data. Here, we present an improved strategy for learning representations of treatment effects from high-throughput imaging, following a causal interpretation. We use weakly supervised learning for modeling associations between images and treatments, and show that it encodes both confounding factors and phenotypic features in the learned representation. To facilitate their separation, we constructed a large training dataset with images from five different studies to maximize experimental diversity, following insights from our causal analysis. Training a model with this dataset successfully improves downstream performance, and produces a reusable convolutional network for image-based profiling, which we call Cell Painting CNN. We evaluated our strategy on three publicly available Cell Painting datasets, and observed that the Cell Painting CNN improves performance in downstream analysis up to 30% with respect to classical features, while also being more computationally efficient.
Assessing cell phenotypes in image-based assays requires solid computational methods for transforming images into quantitative data. Here, the authors present a strategy for learning representations of treatment effects from high-throughput imaging, following a causal interpretation.
Journal Article
Improving measurement of functional status among older adults in primary care: A pilot study
by
Nicosia, Francesca M.
,
Santiago, Lea
,
Spar, Malena J.
in
Acceptability
,
Activities of Daily Living
,
Adults
2024
Despite its importance for clinical care and outcomes among older adults, functional status–the ability to perform basic activities of daily living (ADLs) and instrumental ADLs (IADLs)–is seldom routinely measured in primary care settings. The objective of this study was to pilot test a person-centered, interprofessional intervention to improve identification and management of functional impairment among older adults in Veterans Affairs (VA) primary care practices. The four-component intervention included (1) an interprofessional educational session; (2) routine, standardized functional status measurement among patients aged ≥75; (3) annual screening by nurses using a standardized instrument and follow-up assessment by primary care providers; and (4) electronic tools and templates to facilitate increased identification and improved management of functional impairment. Surveys, semi-structured interviews, and electronic health record data were used to measure implementation outcomes (appropriateness, acceptability and satisfaction, feasibility, fidelity, adoption/reach, sustainability). We analyzed qualitative interviews using rapid qualitative analysis. During the study period, all 959 eligible patients were screened (100% reach), of whom 7.3% (n = 58) reported difficulty or needing help with ≥1 ADL and 11.8% (n = 113) reported difficulty or needing help with ≥1 IADL. In a chart review among a subset of 50 patients with functional impairment, 78% percent of clinician notes for the visit when screening was completed had content related to function, and 48% of patients had referrals ordered to address impairments (e.g., physical therapy) within 1 week. Clinicians highly rated the quality of the educational session and reported increased ability to measure and communicate about function. Clinicians and patients reported that the intervention was appropriate, acceptable, and feasible to complete, even during the COVID pandemic. These findings suggest that this intervention is a promising approach to improve identification and management of functional impairment for older patients in primary care. Broader implementation and evaluation of this intervention is currently underway.
Journal Article
Tumor-infiltrating mast cells are associated with resistance to anti-PD-1 therapy
2021
Anti-PD-1 therapy is used as a front-line treatment for many cancers, but mechanistic insight into this therapy resistance is still lacking. Here we generate a humanized (Hu)-mouse melanoma model by injecting fetal liver-derived CD34
+
cells and implanting autologous thymus in immune-deficient NOD-
scid
IL2Rγ
null
(NSG) mice. Reconstituted Hu-mice are challenged with HLA-matched melanomas and treated with anti-PD-1, which results in restricted tumor growth but not complete regression. Tumor RNA-seq, multiplexed imaging and immunohistology staining show high expression of chemokines, as well as recruitment of FOXP3
+
Treg and mast cells, in selective tumor regions. Reduced HLA-class I expression and CD8
+
/Granz B
+
T cells homeostasis are observed in tumor regions where FOXP3
+
Treg and mast cells co-localize, with such features associated with resistance to anti-PD-1 treatment. Combining anti-PD-1 with sunitinib or imatinib results in the depletion of mast cells and complete regression of tumors. Our results thus implicate mast cell depletion for improving the efficacy of anti-PD-1 therapy.
Immune checkpoint therapies (ICT) are promising for treating various cancers, but response rates vary. Here the authors show, in mouse models, that tumor-infiltrating mast cells colocalize with regulatory T cells, coincide with local reduction of MHC-I and CD8 T cells, and is associated with resistance to ICT, which can be reversed by c-kit inhibitor treatment.
Journal Article
Performance of the Trioplex real-time RT-PCR assay for detection of Zika, dengue, and chikungunya viruses
2018
The emergence and spread of Zika virus (ZIKV) presented a challenge to the diagnosis of ZIKV infections in areas with transmission of dengue (DENV) and chikungunya (CHIKV) viruses. To facilitate detection of ZIKV infections, and differentiate these infections from DENV and CHIKV, we developed the Trioplex real-time RT-PCR assay (Trioplex assay). Here, we describe the optimization of multiplex and singleplex formats of the assay for a variety of chemistries and instruments to facilitate global standardization and implementation. We evaluated the analytical performance of all Trioplex modalities for detection of these three pathogens in serum and whole blood, and for ZIKV in urine. The limit of detection for the three viruses and in different RNA-extraction modalities is near 10
3
genome copy equivalents per milliliter (GCE/mL). Simultaneous testing of more than one specimen type from each patient provides a 6.4% additional diagnostic sensitivity. Overall, the high sensitivity of the Trioplex assay demonstrates the utility of this assay ascertaining Zika cases.
The Trioplex real-time RT-PCR assay was developed for detection of Zika virus infections in areas with dengue and chikungunya transmission. Here, Santiago et al. describe the optimization and clinical performance of the assay, showing high sensitivity for detection and differentiation of the three viruses.
Journal Article
Structural and functional analysis of the role of the chaperonin CCT in mTOR complex assembly
2019
The mechanistic target of rapamycin (mTOR) kinase forms two multi-protein signaling complexes, mTORC1 and mTORC2, which are master regulators of cell growth, metabolism, survival and autophagy. Two of the subunits of these complexes are mLST8 and Raptor, β-propeller proteins that stabilize the mTOR kinase and recruit substrates, respectively. Here we report that the eukaryotic chaperonin CCT plays a key role in mTORC assembly and signaling by folding both mLST8 and Raptor. A high resolution (4.0 Å) cryo-EM structure of the human mLST8-CCT intermediate isolated directly from cells shows mLST8 in a near-native state bound to CCT deep within the folding chamber between the two CCT rings, and interacting mainly with the disordered N- and C-termini of specific CCT subunits of both rings. These findings describe a unique function of CCT in mTORC assembly and a distinct binding site in CCT for mLST8, far from those found for similar β-propeller proteins.
β-propeller domains are an important class of folding substrates for the eukaryotic cytosolic chaperonin CTT. Here the authors find that CTT contributes to the folding and assembly of two β-propeller proteins from mTOR complexes, mLST8 and Raptor, and determine the 4.0 Å cryoEM structure of a human mLST8-CCT intermediate that shows mLST8 in a near-native state.
Journal Article
Introduction and Spread of Dengue Virus 3, Florida, USA, May 2022–April 2023
by
Grubaugh, Nathan D.
,
Stanek, Danielle R.
,
Breban, Mallery I.
in
Analysis
,
Base Sequence
,
Dengue - epidemiology
2024
During May 2022-April 2023, dengue virus serotype 3 was identified among 601 travel-associated and 61 locally acquired dengue cases in Florida, USA. All 203 sequenced genomes belonged to the same genotype III lineage and revealed potential transmission chains in which most locally acquired cases occurred shortly after introduction, with little sustained transmission.
Journal Article
Update on lymphoproliferative disorders of the gastrointestinal tract: disease spectrum from indolent lymphoproliferations to aggressive lymphomas
by
Goodlad, John R
,
Traverse-Glehen Alexandra
,
Oschlies Ilske
in
Axl protein
,
B-cell lymphoma
,
Diagnostic systems
2020
This paper summarizes two sessions of the workshop during the XIX meeting of the European Association for Haematopathology (EAHP) held in Edinburgh in September 2018 dedicated to lymphomas of the gastrointestinal tract. The first session focused on the clinical and pathological features of primary gastrointestinal T cell and NK-cell lymphoproliferative disorders. The distinction between precursor lesions (RCD type 2) and enteropathy-associated T cell lymphoma were stressed, including the discussion of new diagnostic markers for the identification of aberrant phenotypes. Indolent T cell lymphoproliferative disorders of the gastrointestinal tract cases showed phenotypic heterogeneity with novel molecular alterations in few cases, such as STAT3-JAK2 fusion. In addition, novel clonal markers of disease, such as AXL and JAK3 somatic variants support the neoplastic nature of NK-cell enteropathy. The session on gastrointestinal tract B cell lymphoproliferations was dedicated to B cell lymphoproliferative disorders that arise primarily in the gastrointestinal tract (i.e., duodenal-type follicular lymphoma) or preferentially involve the digestive tract, such as large B cell lymphoma with IRF4 translocation and mantle cell lymphoma (MCL), including diverse molecular subtypes (i.e., CCND3-positive MCL mimicking MALT lymphoma). Challenging cases of high-grade B cell lymphomas with complex genetic profiles demonstrated the usefulness of novel molecular diagnostic methods such as targeted NGS to identify high-risk genetic features with potential clinical impact.
Journal Article
Transcatheter Valve Replacement in Severe Tricuspid Regurgitation
2025
Severe tricuspid regurgitation is associated with disabling symptoms and an increased risk of death. Data regarding outcomes after percutaneous transcatheter tricuspid-valve replacement are needed.
In this international, multicenter trial, we randomly assigned 400 patients with severe symptomatic tricuspid regurgitation in a 2:1 ratio to undergo either transcatheter tricuspid-valve replacement and medical therapy (valve-replacement group) or medical therapy alone (control group). The hierarchical composite primary outcome was death from any cause, implantation of a right ventricular assist device or heart transplantation, postindex tricuspid-valve intervention, hospitalization for heart failure, an improvement of at least 10 points in the score on the Kansas City Cardiomyopathy Questionnaire overall summary (KCCQ-OS), an improvement of at least one New York Heart Association (NYHA) functional class, and an improvement of at least 30 m on the 6-minute walk distance. A win ratio was calculated for the primary outcome by comparing all possible patient pairs, starting with the first event in the hierarchy.
A total of 267 patients were assigned to the valve-replacement group and 133 to the control group. At 1 year, the win ratio favoring valve replacement was 2.02 (95% confidence interval [CI], 1.56 to 2.62; P<0.001). In comparisons of patient pairs, those in the valve-replacement group had more wins than the control group with respect to death from any cause (14.8% vs. 12.5%), postindex tricuspid-valve intervention (3.2% vs. 0.6%), and improvement in the KCCQ-OS score (23.1% vs. 6.0%), NYHA class (10.2% vs. 0.8%), and 6-minute walk distance (1.1% vs. 0.9%). The valve-replacement group had fewer wins than the control group with respect to the annualized rate of hospitalization for heart failure (9.7% vs. 10.0%). Severe bleeding occurred in 15.4% of the valve-replacement group and in 5.3% of the control group (P = 0.003); new permanent pacemakers were implanted in 17.4% and 2.3%, respectively (P<0.001).
For patients with severe tricuspid regurgitation, transcatheter tricuspid-valve replacement was superior to medical therapy alone for the primary composite outcome, driven primarily by improvements in symptoms and quality of life. (Funded by Edwards Lifesciences; TRISCEND II ClinicalTrials.gov number, NCT04482062.).
Journal Article
Resistance to autosomal dominant Alzheimer’s disease in an APOE3 Christchurch homozygote: a case report
by
Su, Yi
,
Pardilla-Delgado, Enmanuelle
,
Rios-Romenets, Silvia
in
Alzheimer's disease
,
Apolipoprotein E
,
Brain research
2019
We identified a PSEN1 (presenilin 1) mutation carrier from the world’s largest autosomal dominant Alzheimer’s disease kindred, who did not develop mild cognitive impairment until her seventies, three decades after the expected age of clinical onset. The individual had two copies of the APOE3 Christchurch (R136S) mutation, unusually high brain amyloid levels and limited tau and neurodegenerative measurements. Our findings have implications for the role of APOE in the pathogenesis, treatment and prevention of Alzheimer’s disease.
Journal Article