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3.
J Magn Reson Imaging ; 59(3): 1070-1073, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-37246446

RESUMEN

BACKGROUND: Nonalcoholic fatty liver disease (NAFLD) is a leading cause of end-stage liver disease. NAFLD diagnosis and follow-up relies on a combination of clinical data, liver imaging, and/or liver biopsy. However, intersite imaging differences impede diagnostic consistency and reduce the repeatability of the multisite clinical trials necessary to develop effective treatments. PURPOSE/HYPOTHESIS: The goal of this pilot study was to harmonize commercially available 3 T magnetic resonance imaging (MRI) measurements of liver fat and stiffness in human participants across academic sites and MRI vendors. STUDY TYPE: Cohort. SUBJECTS: Four community-dwelling adults with obesity. FIELD STRENGTH/SEQUENCE: 1.5 and 3 T, multiecho 3D imaging, PRESS, and GRE. ASSESSMENT: Harmonized proton density fat fraction (PDFF) and magnetic resonance spectroscopy (MRS) protocols were used to quantify the FF of synthetic phantoms and human participants with obesity using standard acquisition parameters at four sites that had four different 3 T MRI instruments. In addition, a harmonized magnetic resonance elastography (MRE) protocol was used to quantify liver stiffness among participants at two different sites at 1.5 and 3 T field strengths. Data were sent to a single data coordinating site for postprocessing. STATISTICAL TESTS: Linear regression in MATLAB, ICC analyses using SAS 9.4, one-sided 95% confidence intervals for the ICC. RESULTS: PDFF and MRS FF measurements were highly repeatable among sites in both humans and phantoms. MRE measurements of liver stiffness in three individuals at two sites using one 1.5 T and one 3 T instrument showed repeatability that was high although lower than that of MRS and PDFF. CONCLUSIONS: We demonstrated harmonization of PDFF, MRS, and MRE-based quantification of liver fat and stiffness through synthetic phantoms, traveling participants, and standardization of postprocessing analysis. Multisite MRI harmonization could contribute to multisite clinical trials assessing the efficacy of interventions and therapy for NAFLD. LEVEL OF EVIDENCE: 2 TECHNICAL EFFICACY STAGE: 2.


Asunto(s)
Enfermedad del Hígado Graso no Alcohólico , Adulto , Humanos , Enfermedad del Hígado Graso no Alcohólico/patología , Proyectos Piloto , Reproducibilidad de los Resultados , Hígado/patología , Imagen por Resonancia Magnética/métodos , Obesidad/patología
4.
JAMA Netw Open ; 6(10): e2336470, 2023 10 02.
Artículo en Inglés | MEDLINE | ID: mdl-37796498

RESUMEN

Importance: Multicenter clinical trials play a critical role in the translational processes that enable new treatments to reach all people and improve public health. However, conducting multicenter randomized clinical trials (mRCT) presents challenges. The Trial Innovation Network (TIN), established in 2016 to partner with the Clinical and Translational Science Award (CTSA) Consortium of academic medical institutions in the implementation of mRCTs, consists of 3 Trial Innovation Centers (TICs) and 1 Recruitment Innovation Center (RIC). This unique partnership has aimed to address critical roadblocks that impede the design and conduct of mRCTs, in expectation of accelerating the translation of novel interventions to clinical practice. The TIN's challenges and achievements are described in this article, along with examples of innovative resources and processes that may serve as useful models for other clinical trial networks providing operational and recruitment support. Observations: The TIN has successfully integrated more than 60 CTSA institution program hubs into a functional network for mRCT implementation and optimization. A unique support system for investigators has been created that includes the development and deployment of novel tools, operational and recruitment services, consultation models, and rapid communication pathways designed to reduce delays in trial start-up, enhance recruitment, improve engagement of diverse research participants and communities, and streamline processes that improve the quality, efficiency, and conduct of mRCTs. These resources and processes span the clinical trial spectrum and enable the TICs and RIC to serve as coordinating centers, data centers, and recruitment specialists to assist trials across the National Institutes of Health and other agencies. The TIN's impact has been demonstrated through its response to both historical operational challenges and emerging public health emergencies, including the national opioid public health crisis and the COVID-19 pandemic. Conclusions and Relevance: The TIN has worked to reduce barriers to implementing mRCTs and to improve mRCT processes and operations by providing needed clinical trial infrastructure and resources to CTSA investigators. These resources have been instrumental in more quickly and efficiently translating research discoveries into beneficial patient treatments.


Asunto(s)
Distinciones y Premios , COVID-19 , Estados Unidos , Humanos , Pandemias , Ciencia Traslacional Biomédica , Comunicación
5.
medRxiv ; 2023 Oct 21.
Artículo en Inglés | MEDLINE | ID: mdl-37904956

RESUMEN

Due to a combination of asymptomatic or undiagnosed infections, the proportion of the United States population infected with SARS-CoV-2 was unclear from the beginning of the pandemic. We previously established a platform to screen for SARS-CoV-2 positivity across a representative proportion of the US population, from which we reported that almost 17 million Americans were estimated to have had undocumented infections in the Spring of 2020. Since then, vaccine rollout and prevalence of different SARS-CoV-2 variants have further altered seropositivity trends within the United States population. To explore the longitudinal impacts of the pandemic and vaccine responses on seropositivity, we re-enrolled participants from our baseline study in a 6- and 12- month follow-up study to develop a longitudinal antibody profile capable of representing seropositivity within the United States during a critical period just prior to and during the initiation of vaccine rollout. Initial measurements showed that, since July 2020, seropositivity elevated within this population from 4.8% at baseline to 36.2% and 89.3% at 6 and 12 months, respectively. We also evaluated nucleocapsid seropositivity and compared to spike seropositivity to identify trends in infection versus vaccination relative to baseline. These data serve as a window into a critical timeframe within the COVID-19 pandemic response and serve as a resource that could be used in subsequent respiratory illness outbreaks.

6.
Med Educ Online ; 28(1): 2182188, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-36861296

RESUMEN

The University of Alabama at Birmingham Heersink School of Medicine established the Pittman Scholars Program in 2015 to elevate scientific impact and to support the recruitment and retention of highly competitive junior faculty. The authors examined the impact of this program on research productivity and on faculty retention. The authors evaluated publications and extramural grant awards and available demographic data for the Pittman Scholars compared to all junior faculty in the Heersink School of Medicine. From 2015 to 2021, the program awarded a diverse group of 41 junior faculty members across the institution. For this cohort, ninety-four new extramural grants were awarded and 146 grant applications were submitted since the inception of the scholar award. Pittman Scholars published a total of 411 papers during the term of the award. The faculty retention rate of the scholars was 95%, comparable to that of all Heersink junior faculty, with 2 recipients being recruited to other institutions. The implementation of the Pittman Scholars Program has been an effective strategy to celebrate scientific impact and acknowledge junior faculty members as outstanding scientists at our institution. The Pittman Scholars award allows junior faculty to use funds for their research program, publications, collaborations, and career advancement. The Pittman Scholars are recognized at local, regional, and national levels for the work they are contributing to academic medicine. The program has served as an important pipeline faculty development program and an avenue for individual recognition for research-intensive faculty.


Asunto(s)
Docentes , Medicina , Médicos , Humanos , Universidades
7.
J Clin Transl Sci ; 7(1): e13, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36755544

RESUMEN

As the COVID-19 pandemic took hold in the USA in early 2020, it became clear that knowledge of the prevalence of antibodies to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) among asymptomatic individuals could inform public health policy decisions and provide insight into the impact of the infection on vulnerable populations. Two Clinical and Translational Science Award (CTSA) Hubs and the National Institutes of Health (NIH) set forth to conduct a national seroprevalence survey to assess the infection's rate of spread. This partnership was able to quickly design and launch the project by leveraging established research capacities, prior experiences in large-scale, multisite studies and a highly skilled workforce of CTSA hubs and unique experimental capabilities at the NIH to conduct a diverse prospective, longitudinal observational cohort of 11,382 participants who provided biospecimens and participant-reported health and behavior data. The study was completed in 16 months and benefitted from transdisciplinary teamwork, information technology innovations, multimodal communication strategies, and scientific partnership for rigor in design and analytic methods. The lessons learned by the rapid implementation and dissemination of this national study is valuable in guiding future multisite projects as well as preparation for other public health emergencies and pandemics.

8.
Am J Health Promot ; 37(5): 720-721, 2023 06.
Artículo en Inglés | MEDLINE | ID: mdl-36630288

RESUMEN

The purpose of this submission to respond to a Letter to the Editor recently submitted regarding our manuscript, "Exploring COVID-19 Vaccine Hesitancy among Stakeholders in African American and Latinx Communities in the Deep South through the Lens of the Health Belief Model" published in the American Journal of Health Promotion in February, 2022. The manuscript reported on a study that had as its purpose to qualitatively explore perceptions related to COVID-19 vaccination intention among African American and Latinx participants and suggest potential intervention strategies.


Asunto(s)
Vacunas contra la COVID-19 , COVID-19 , Humanos , Negro o Afroamericano , COVID-19/prevención & control , Modelo de Creencias sobre la Salud , Vacunación , Hispánicos o Latinos
10.
Am J Health Promot ; 36(2): 288-295, 2022 02.
Artículo en Inglés | MEDLINE | ID: mdl-34719985

RESUMEN

PURPOSE: The purpose of this study was to qualitatively explore perceptions related to COVID-19 vaccination intention among African American and Latinx participants and suggest intervention strategies. APPROACH: Ninety minute virtual focus groups (N = 8), segmented by county, race and ethnicity were conducted with stakeholders from 3 vulnerable Alabama counties. PARTICIPANTS: Participants (N = 67) were primarily African American and Latinx, at least 19 years, and residents or stakeholders in Jefferson, Mobile, and Dallas counties. SETTING: Focus groups took place virtually over Zoom. METHODS: The semi-structured guide explored perceptions of COVID-19, with an emphasis on barriers and facilitators to vaccine uptake. Focus groups lasted approximately 90 minutes and were audio recorded, transcribed, and analyzed by a team of 3 investigators, according to the guidelines of Thematic Analysis using NVivo 12. To provide guidance in the development of interventions to decrease vaccine hesitancy, we examined how themes fit with the constructs of the Health Belief Model. RESULTS: We found that primary themes driving COVID-19 vaccine hesitancy, ordered from most to least discussed, are mistrust, fear, and lack of information. Additionally, interventions to decrease vaccine hesitancy should be multi-modal, community engaged, and provide consistent, comprehensive messages delivered by trusted sources.


Asunto(s)
Vacunas contra la COVID-19 , COVID-19 , Negro o Afroamericano , Humanos , SARS-CoV-2 , Vacilación a la Vacunación
11.
Nat Genet ; 53(7): 962-971, 2021 07.
Artículo en Inglés | MEDLINE | ID: mdl-34127860

RESUMEN

We report the largest and most diverse genetic study of type 1 diabetes (T1D) to date (61,427 participants), yielding 78 genome-wide-significant (P < 5 × 10-8) regions, including 36 that are new. We define credible sets of T1D-associated variants and show that they are enriched in immune-cell accessible chromatin, particularly CD4+ effector T cells. Using chromatin-accessibility profiling of CD4+ T cells from 115 individuals, we map chromatin-accessibility quantitative trait loci and identify five regions where T1D risk variants co-localize with chromatin-accessibility quantitative trait loci. We highlight rs72928038 in BACH2 as a candidate causal T1D variant leading to decreased enhancer accessibility and BACH2 expression in T cells. Finally, we prioritize potential drug targets by integrating genetic evidence, functional genomic maps and immune protein-protein interactions, identifying 12 genes implicated in T1D that have been targeted in clinical trials for autoimmune diseases. These findings provide an expanded genomic landscape for T1D.


Asunto(s)
Alelos , Mapeo Cromosómico , Diabetes Mellitus Tipo 1/genética , Predisposición Genética a la Enfermedad , Variación Genética , Genómica , Autoinmunidad/genética , Linfocitos T CD4-Positivos/inmunología , Linfocitos T CD4-Positivos/metabolismo , Diabetes Mellitus Tipo 1/tratamiento farmacológico , Diabetes Mellitus Tipo 1/metabolismo , Descubrimiento de Drogas , Expresión Génica , Genómica/métodos , Humanos , Terapia Molecular Dirigida , Mapeo de Interacción de Proteínas
12.
Sci Transl Med ; 13(601)2021 07 07.
Artículo en Inglés | MEDLINE | ID: mdl-34158410

RESUMEN

Asymptomatic SARS-CoV-2 infection and delayed implementation of diagnostics have led to poorly defined viral prevalence rates in the United States and elsewhere. To address this, we analyzed seropositivity in 9089 adults in the United States who had not been diagnosed previously with COVID-19. Individuals with characteristics that reflected the U.S. population (n = 27,716) were selected by quota sampling from 462,949 volunteers. Enrolled participants (n = 11,382) provided medical, geographic, demographic, and socioeconomic information and dried blood samples. Survey questions coincident with the Behavioral Risk Factor Surveillance System survey, a large probability-based national survey, were used to adjust for selection bias. Most blood samples (88.7%) were collected between 10 May and 31 July 2020 and were processed using ELISA to measure seropositivity (IgG and IgM antibodies against SARS-CoV-2 spike protein and the spike protein receptor binding domain). The overall weighted undiagnosed seropositivity estimate was 4.6% (95% CI, 2.6 to 6.5%), with race, age, sex, ethnicity, and urban/rural subgroup estimates ranging from 1.1% to 14.2%. The highest seropositivity estimates were in African American participants; younger, female, and Hispanic participants; and residents of urban centers. These data indicate that there were 4.8 undiagnosed SARS-CoV-2 infections for every diagnosed case of COVID-19, and an estimated 16.8 million infections were undiagnosed by mid-July 2020 in the United States.


Asunto(s)
COVID-19 , Pandemias , Adulto , Anticuerpos Antivirales , Femenino , Humanos , SARS-CoV-2 , Glicoproteína de la Espiga del Coronavirus , Estados Unidos/epidemiología
13.
J Clin Transl Sci ; 5(1): e92, 2021 Feb 05.
Artículo en Inglés | MEDLINE | ID: mdl-34192049

RESUMEN

Biospecimen repositories play a vital role in enabling investigation of biologic mechanisms, identification of disease-related biomarkers, advances in diagnostic assays, recognition of microbial evolution, and characterization of new therapeutic targets for intervention. They rely on the complex integration of scientific need, regulatory oversight, quality control in collection, processing and tracking, and linkage to robust phenotype information. The COVID-19 pandemic amplified many of these considerations and illuminated new challenges, all while academic health centers were trying to adapt to unprecedented clinical demands and heightened research constraints not witnessed in over 100 years. The outbreak demanded rapid understanding of SARS-CoV-2 to develop diagnostics and therapeutics, prompting the immediate need for access to high quality, well-characterized COVID-19-associated biospecimens. We surveyed 60 Clinical and Translational Science Award (CTSA) hubs to better understand the strategies and barriers encountered in biobanking before and in response to the COVID-19 pandemic. Feedback revealed a major shift in biorepository model, specimen-acquisition and consent process from a combination of investigator-initiated and institutional protocols to an enterprise-serving strategy. CTSA hubs were well equipped to leverage established capacities and expertise to quickly respond to the scientific needs of this crisis through support of institutional approaches in biorepository management.

14.
J Clin Transl Sci ; 5(1): e96, 2021 Feb 18.
Artículo en Inglés | MEDLINE | ID: mdl-34192053

RESUMEN

The 2020 COVID-19 pandemic has had a profound impact on the clinical research enterprises at the 60 Clinical and Translational Science Award (CTSA) Hubs throughout the nation. There was simultaneously a need to expand research to obtain crucial data about disease prognosis and therapy and enormous limitations on conducting research as localities and institutions limited travel and person-to-person contact. These imperatives resulted in major changes in the way research was conducted, including expediting Institutional Review Board review, shifting to remote interactions with participants, centralizing decision-making in prioritizing research protocols, establishing biobanks, adopting novel informatics platforms, and distributing study drugs in unconventional ways. National CTSA Steering Committee meetings provided an opportunity to share best practices and develop the idea of capturing the CTSA program experiences in a series of papers. Here we bring together the recommendations from those papers in a list of specific actions that research sites can take to strengthen operations and prepare for similar future public health emergencies. Most importantly, creative innovations developed in response to the COVID-19 pandemic deserve serious consideration for adoption as new standards, thus converting the painful trauma of the pandemic into "post-traumatic growth" that makes the clinical research enterprise stronger, more resilient, and more effective.

15.
Acad Med ; 96(10): 1401-1407, 2021 10 01.
Artículo en Inglés | MEDLINE | ID: mdl-33830950

RESUMEN

The University of Alabama at Birmingham academic medical center (UAB AMC) had achieved great success and growth during the 50 years since its founding. However, the challenging and more competitive environment of the 2000s left the UAB AMC on a downward trajectory. The UAB AMC had to overcome difficult internal cultural and structural barriers that stood in the way of the transformational change needed to remain competitive. Competition rather than collaborative and strategic financial investment were the primary cultural barriers for the UAB AMC, while people were the primary structural barrier. Leadership identified 5 steps that were critical for the transformation that occurred between 2013 and 2018: alignment of leadership; creating a compelling and credible shared vision; identifying cultural and structural barriers; creating a thoughtful, data-driven intervention; and improved communication and accountability. Following these steps enabled the UAB AMC to transform its institutional structure and culture. As a result, the UAB AMC thrived, returning to substantial growth in research and clinical care. UAB AMC School of Medicine grew by $100 million in National Institutes of Health funding and moved up 10 spots in ranking. In 2018, UAB Hospital had 10 specialties ranked by U.S. News & World Report, 7 more than in 2013. This article outlines the approach taken and provides a conceptual framework for other AMCs eager to transform their structure and culture and position themselves for growth.


Asunto(s)
Centros Médicos Académicos/organización & administración , Gestión del Cambio , Centros Médicos Académicos/economía , Alabama , Financiación Gubernamental , Humanos , Liderazgo , Cultura Organizacional , Objetivos Organizacionales , Apoyo a la Investigación como Asunto , Comunicación Académica , Responsabilidad Social
16.
medRxiv ; 2021 Jan 31.
Artículo en Inglés | MEDLINE | ID: mdl-33532807

RESUMEN

Asymptomatic SARS-CoV-2 infection and delayed implementation of diagnostics have led to poorly defined viral prevalence rates. To address this, we analyzed seropositivity in US adults who have not previously been diagnosed with COVID-19. Individuals with characteristics that reflect the US population (n = 11,382) and who had not previously been diagnosed with COVID-19 were selected by quota sampling from 241,424 volunteers (ClinicalTrials.gov NCT04334954). Enrolled participants provided medical, geographic, demographic, and socioeconomic information and 9,028 blood samples. The majority (88.7%) of samples were collected between May 10th and July 31st, 2020. Samples were analyzed via ELISA for anti-Spike and anti-RBD antibodies. Estimation of seroprevalence was performed by using a weighted analysis to reflect the US population. We detected an undiagnosed seropositivity rate of 4.6% (95% CI: 2.6 - 6.5%). There was distinct regional variability, with heightened seropositivity in locations of early outbreaks. Subgroup analysis demonstrated that the highest estimated undiagnosed seropositivity within groups was detected in younger participants (ages 18-45, 5.9%), females (5.5%), Black/African American (14.2%), Hispanic (6.1%), and Urban residents (5.3%), and lower undiagnosed seropositivity in those with chronic diseases. During the first wave of infection over the spring/summer of 2020 an estimate of 4.6% of adults had a prior undiagnosed SARS-CoV-2 infection. These data indicate that there were 4.8 (95% CI: 2.8-6.8) undiagnosed cases for every diagnosed case of COVID-19 during this same time period in the United States, and an estimated 16.8 million undiagnosed cases by mid-July 2020.

17.
Hum Mol Genet ; 29(15): 2523-2534, 2020 08 29.
Artículo en Inglés | MEDLINE | ID: mdl-32628254

RESUMEN

A common feature of autoimmune diseases, including systemic lupus erythematosus (SLE), is an increased prevalence in women. However, the molecular basis for sex disparity in SLE remains poorly understood. To examine the role of X-linked transcription in SLE adaptive immune cells, we performed RNA-seq in T cell and B cell subsets from either healthy donors or patients with SLE. Analyses of allelic expression (AE) profiles identified a pattern of increased allelic imbalance across the entire X chromosome in SLE lymphocytes. X-linked genes exhibiting AE in SLE had an extensive overlap with genes known to escape X chromosome inactivation (XCI). XIST RNA was overexpressed in SLE patients. Differential XIST expression correlated with AE profiles more positively at X-linked genes than the genome-wide background. Analysis of three independent RNA-seq data verified the XIST-associated skewed AE on X chromosome in SLE. Integrative analyses of DNA methylation profiles showed an increased variability of DNA methylation levels at these AE-related X-linked genes. In cultured lymphoblastic cells, knockdown of XIST specifically altered allelic imbalance patterns between X chromosomes. Our study provides genetic evidence that upregulation of XIST accompanied with more skewed allelic expression on X chromosome is associated with the pathogenesis of SLE and may provide mechanistic insights into the increased incidence of SLE in females.


Asunto(s)
Metilación de ADN/genética , Lupus Eritematoso Sistémico/genética , ARN Largo no Codificante/genética , Linfocitos T/metabolismo , Inactivación del Cromosoma X/genética , Adulto , Alelos , Línea Celular , Cromosomas Humanos X/genética , Femenino , Regulación de la Expresión Génica/genética , Genes Ligados a X/genética , Humanos , Lupus Eritematoso Sistémico/patología , Linfocitos/patología , RNA-Seq , Linfocitos T/patología
18.
Nature ; 582(7813): 577-581, 2020 06.
Artículo en Inglés | MEDLINE | ID: mdl-32499649

RESUMEN

Many common illnesses, for reasons that have not been identified, differentially affect men and women. For instance, the autoimmune diseases systemic lupus erythematosus (SLE) and Sjögren's syndrome affect nine times more women than men1, whereas schizophrenia affects men with greater frequency and severity relative to women2. All three illnesses have their strongest common genetic associations in the major histocompatibility complex (MHC) locus, an association that in SLE and Sjögren's syndrome has long been thought to arise from alleles of the human leukocyte antigen (HLA) genes at that locus3-6. Here we show that variation of the complement component 4 (C4) genes C4A and C4B, which are also at the MHC locus and have been linked to increased risk for schizophrenia7, generates 7-fold variation in risk for SLE and 16-fold variation in risk for Sjögren's syndrome among individuals with common C4 genotypes, with C4A protecting more strongly than C4B in both illnesses. The same alleles that increase risk for schizophrenia greatly reduce risk for SLE and Sjögren's syndrome. In all three illnesses, C4 alleles act more strongly in men than in women: common combinations of C4A and C4B generated 14-fold variation in risk for SLE, 31-fold variation in risk for Sjögren's syndrome, and 1.7-fold variation in schizophrenia risk among men (versus 6-fold, 15-fold and 1.26-fold variation in risk among women, respectively). At a protein level, both C4 and its effector C3 were present at higher levels in cerebrospinal fluid and plasma8,9 in men than in women among adults aged between 20 and 50 years, corresponding to the ages of differential disease vulnerability. Sex differences in complement protein levels may help to explain the more potent effects of C4 alleles in men, women's greater risk of SLE and Sjögren's syndrome and men's greater vulnerability to schizophrenia. These results implicate the complement system as a source of sexual dimorphism in vulnerability to diverse illnesses.


Asunto(s)
Complemento C3/genética , Complemento C4/genética , Lupus Eritematoso Sistémico/genética , Caracteres Sexuales , Síndrome de Sjögren/genética , Adulto , Alelos , Complemento C3/análisis , Complemento C3/líquido cefalorraquídeo , Complemento C4/análisis , Complemento C4/líquido cefalorraquídeo , Femenino , Predisposición Genética a la Enfermedad , Antígenos HLA/genética , Haplotipos , Humanos , Lupus Eritematoso Sistémico/sangre , Lupus Eritematoso Sistémico/líquido cefalorraquídeo , Complejo Mayor de Histocompatibilidad/genética , Masculino , Persona de Mediana Edad , Síndrome de Sjögren/sangre , Síndrome de Sjögren/líquido cefalorraquídeo , Adulto Joven
19.
Bioinformatics ; 36(1): 10-16, 2020 01 01.
Artículo en Inglés | MEDLINE | ID: mdl-31214684

RESUMEN

MOTIVATION: Meiotic recombination facilitates the transmission of exchanged genetic material between homologous chromosomes and plays a crucial role in increasing the genetic variations in eukaryotic organisms. In humans, thousands of crossover events have been identified by genotyping related family members. However, most of these crossover regions span tens to hundreds of kb, which is not sufficient resolution to accurately identify the crossover breakpoints in a typical trio family. RESULTS: We have developed MRLR, a software using 10X linked reads to identify crossover events at a high resolution. By reconstructing the gamete genome, MRLR only requires a trio family dataset and can efficiently discover the crossover events. Using MRLR, we revealed a fine-scale pattern of crossover regions in six human families. From the two closest heterozygous alleles around the crossovers, we determined that MRLR achieved a median resolution 4.5 kb. This method can delineate a genome-wide landscape of crossover events at a precise scale, which is important for both functional and genomic features analysis of meiotic recombination. AVAILABILITY AND IMPLEMENTATION: MRLR is freely available at https://github.com/ChongLab/MRLR, implemented in Perl. SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.


Asunto(s)
Intercambio Genético , Genómica , Meiosis , Programas Informáticos , Intercambio Genético/genética , Genómica/métodos , Recombinación Homóloga/genética , Humanos , Meiosis/genética , Programas Informáticos/normas
20.
Arthritis Rheumatol ; 72(2): 282-291, 2020 02.
Artículo en Inglés | MEDLINE | ID: mdl-31430064

RESUMEN

OBJECTIVE: To determine the stage of B cell development at which a systemic lupus erythematosus (SLE)-associated DNA methylation signature originates in African American (AA) and European American (EA) subjects, and to assess whether epigenetic defects in B cell development patterns could be predictive of SLE status in individual and mixed immune cell populations. METHODS: B cells from AA patients (n = 31) and EA patients (n = 49) with or without SLE were sorted using fluorescence-activated cell sorting into 5 B cell subsets. DNA methylation, measured at ~460,000 CpG sites, was interrogated in each subset. Enrichment analysis of transcription factor interaction at SLE-associated methylation sites was performed. A random forests algorithm was used to identify an epigenetic signature of SLE in the B cell subsets, which was then validated in an independent cohort of AA and EA patients and healthy controls. RESULTS: Regression analysis across all B cell stages resulted in identification of 60 CpGs that reached genome-wide significance for SLE-associated methylation differences (P ≤ 1.07 × 10-7 ). Interrogation of ethnicity-specific CpGs associated with SLE revealed a hypomethylated pattern that was enriched for interferon (IFN)-regulated genes and binding of EBF1 in AA patients (each P < 0.001). AA patients with SLE could be distinguished from healthy controls when the predictive model developed with the transitional B cell subset was applied to other B cell subsets (mean receiver operating characteristic [ROC] area under the curve [AUC] 0.98), and when applied to CD19+ pan-B cells (mean ROC AUC 0.95) and CD4+ pan-T cells (mean ROC AUC 0.97) from the independent validation cohort. CONCLUSION: These results indicate that SLE-specific methylation patterns are ethnicity dependent. A pattern of epigenetic changes near IFN-regulated genes early in B cell development is a hallmark of SLE in AA female subjects. EBF1 binding sites are highly enriched for significant methylation changes, implying that this may be a potential regulator of SLE-associated epigenetic changes.


Asunto(s)
Subgrupos de Linfocitos B , Epigénesis Genética , Lupus Eritematoso Sistémico/genética , Lupus Eritematoso Sistémico/inmunología , Negro o Afroamericano , Linaje de la Célula , Metilación de ADN , Femenino , Humanos , Masculino , Población Blanca
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