Now showing items 21-40 of 3848

    • Cellular heterogeneity and gene regulatory network coordination during thymic epithelial cell development

      Magaletta, Margaret (2022-08-23)
      Thymic epithelial cells, derived from the pharyngeal endoderm, perform essential functions for establishing a self-tolerant immune system. Unsurprisingly, dysfunction of thymic epithelial cells resulting from maldevelopment of the pharyngeal endoderm causes immunodeficiency or autoimmunity syndromes, some of which cannot be fully explained according to known genetic errors. Despite the functional significance and disease-relevance of pharyngeal endoderm with respect to thymic epithelial cells, we lack a comprehensive understanding of the gene regulatory networks driving pharyngeal endoderm differentiation. To close this gap, we applied transcriptome and chromatin accessibility single cell profiling to generate a multi-omic developmental resource covering pharyngeal differentiation toward organ-specific epithelia in the mouse embryo. We identified cell-type specific gene regulation of developing organ domains and characterized the role of an immunodeficiency-associated forkhead box transcription factor, Foxn1, during early thymus development. Furthermore, analyses of the pharyngeal endoderm multi-omics atlas led us to discover a novel gene associated with thymus development, namely Grainyhead-like3 (Grhl3). We assessed the expression pattern and the functional importance of Grhl3 in the prenatal and postnatal thymus, uncovering a putative role in a specialized medullary thymic subtype. In conclusion, this dissertation provides insight on the molecular basis of pharyngeal endoderm differentiation and subsequent development of the thymus.
    • Regulated Gene Therapy Towards Glycosphingolipid Biosynthesis Deficiencies

      Yang, Huiya (2022-08-22)
      Glycosphingolipids (GSLs) are a group of amphipathic glycolipids essential for maintaining the normal ultrastructure and function of neural and oligodendrocyte cell membranes throughout the mammalian central nervous system (CNS). De novo GSL biosynthesis defects cause severe neurological diseases such as GM3 synthase deficiency (GM3SD) and hereditary sensory and autonomic neuropathy type 1A (HSAN1A), each lacking effective treatment. Here, we developed two distinct potential therapeutic approaches for these neurological diseases. For GM3SD that is caused by loss-of-function mutations in ST3GAL5, we employed a recombinant adeno-associated virus (rAAV)-mediated human ST3GAL5 gene replacement therapy. First, using ST3GAL5 mutant patient iPSC-derived neurons and St3gal5 knock-out mouse models, we have achieved ST3GAL5 gene normalization and restoration of the functional products, cerebral gangliosides. Importantly, we revealed the hepatic toxicity caused by ubiquitous expression of ST3GAL5 and optimized a CNS-restricted rAAV gene replacement therapy for the safe and efficacious rescue of the severe neurodevelopmental phenotypes and early lethality in disease mouse models, given by both intracerebroventricular and intravenous routes of administration. These results support for further clinical development of ST3GAL5 gene therapy. On the other hand, to target gain-of-function SPTLC1 mutation caused HSAN1A, we screened antisense oligonucleotides (ASOs) and achieved efficient reduction of mutant SPTLC1 transcripts and its toxic products in patient-fibroblasts. In summary, this thesis describes the potential of novel rAAV-mediated gene replacement therapy in GM3SD and allele-specific ASO silencing in HSAN1A, highlighting the significance of personalized gene therapy for monogenic neurological disorders.
    • Cancer; Pathophysiology and Stress Modulation (Cancer, Therapeutic Interventions)

      Scarpetti, Lauren; Guarino, Matthew; Baima, Jennifer (2022-08-19)
      Objective: The purpose of this review is to describe the myriad complications of cancer and its therapies to emphasize the pathophysiological need for prehabilitation. Data sources: The information presented in this review is from applicable, peer-reviewed scientific articles. Conclusion: Cancer itself renders negative effects on the body, most notably unintentional weight loss and fatigue. Cancer treatments, especially surgical interventions, can cause detrimental short- and long-term impacts on patients, which translate to suboptimal treatment outcomes. Prehabilitation can be used to improve patient health prior to anticancer therapies to improve treatment tolerance and efficacy. Implications for nursing practice: Nurses play an important role in the treatment of patients with cancer throughout the cancer care continuum. Many nurses are already aiding their patients in cancer prehabilitation through education. By describing common impairments amenable to multimodal prehabilitation, nurses may better advocate for their patients and can become even more involved in this aspect of care.
    • Video and In-Person Palliative Care Delivery Challenges before and during the COVID-19 Pandemic

      Chua, Isaac S; Olmsted, Molly; Plotke, Rachel; Turk, Yael; Trotter, Chardria; Rinaldi, Simone; Kamdar, Mihir; Jackson, Vicki A; Gallagher-Medeiros, Emily R; El-Jawahri, Areej; et al. (2022-08-17)
      Context: Palliative care (PC) clinicians faced many challenges delivering outpatient care during the coronavirus-19 (COVID-19) pandemic. Objectives: We described trends for in-person and video visit PC delivery challenges before and during the COVID-19 pandemic in the U.S. Methods: We performed a secondary data analysis of patient characteristics and PC clinician surveys from a multisite randomized controlled trial at 20 academic cancer centers. Patients newly diagnosed with advanced lung cancer (N = 653) were randomly assigned to receive either early in-person or telehealth PC and had at least monthly PC clinician visits. PC clinicians completed surveys documenting PC delivery challenges after each encounter. We categorized patients into 3 subgroups according to their PC visit dates relative to the onset of the COVID-19 pandemic in the U.S.-pre-COVID-19 (all visits before March 1, 2020), pre/post-COVID-19 (≥1 visit before and after March 1, 2020), and post-COVID-19 (all visits after March 1, 2020). We performed Pearson's chi-squared, Fisher's exact, and Kruskal-Wallis tests to examine associations. Results: We analyzed 2329 surveys for video visits and 2176 surveys for in-person visits. For video visits, the pre-COVID-19 subgroup (25.8% [46/178]) had the most technical difficulties followed by the pre/post-COVID-19 subgroup (17.2% [307/1784]) and then the post-COVID-19 subgroup (11.4% [42/367]) (P = 0.0001). For in-person visits, challenges related to absent patients' family members occurred most often in the post-COVID-19 subgroup (6.2% [16/259]) followed by the pre/post-COVID-19 subgroup (3.6% [50/1374]) and then the pre-COVID-19 subgroup (2.2% [12/543]) (P = 0.02). Conclusion: Technical difficulties related to PC video visits improved, whereas in-person visit challenges related to absent patients' family members worsened during the pandemic.
    • Investigating Proteolytic Processing of Ataxin 2, a Neurodegenerative Disease Associated Protein

      Chitre, Monika (2022-08-08)
      Ataxin 2 (ATXN2) is a ubiquitously expressed mRNA binding protein involved in the development and progression of spinocerebellar ataxia 2 (SCA2) and amyotrophic lateral sclerosis (ALS). In the context of both neurodegenerative diseases, its N-terminal polyglutamine (polyQ) domain is mutated and expanded in length. Several other polyQ proteins, such as huntingtin (Htt), ataxin 3 (ATXN3), and ataxin 7 (ATXN7), undergo proteolytic processing that produces toxic fragments containing their polyQ domains. Investigating how ATXN2 is regulated by proteolysis is hindered by the lack of available molecular biological tools such as N-terminal ATXN2 antibodies to target and analyze the endogenous N-terminus of ATXN2. To circumvent this challenge, I developed a transient overexpression model of N-terminally tagged ATXN2 in HEK293E cells. Here, I demonstrate that both wild-type and mutant ATXN2 are targets of N-terminal proteolysis. I confirmed that ATXN2 produces an independent polyQ cleavage fragment like other polyQ proteins through basic molecular biology approaches such as Western blotting and immunoprecipitation. Additionally, I identified the specific region that is both necessary and sufficient for cleavage to occur via deletion mapping with multiple truncated ATXN2 mutants and reporter constructs. Further definition of ATXN2 as a target of proteolytic cleavage aligns it with other neurodegenerative polyQ proteins, and proteolysis is currently a less explored avenue of research for ATXN2-related disease development, progression, and therapeutic modalities. This work reveals a novel site that directs cleavage of ATXN2 and provides a potential avenue of investigation for how ATXN2 posttranslational modifications contribute to the progression of SCA2 and ALS.
    • Performance of Screening for SARS-CoV-2 using Rapid Antigen Tests to Detect Incidence of Symptomatic and Asymptomatic SARS-CoV-2 Infection: findings from the Test Us at Home prospective cohort study [preprint]

      Soni, Apurv; Herbert, Carly; Lin, Honghuang; Pretz, Caitlin; Stamegna, Pamela; Orwig, Taylor; Wright, Colton; Tarrant, Seanan; Behar, Stephanie; Suvarna, Thejas; et al. (2022-08-06)
      Background: Performance of Rapid Antigen Tests for SARS-CoV-2 (Ag-RDT) varies over the course of an infection, and their performance is not well established among asymptomatic individuals. Objective: Evaluate performance of Ag-RDT for detection of SARS-CoV-2 in relation to onset of infection for symptomatic and asymptomatic participants. Design setting and participants: Prospective cohort study conducted from October 2021 to February 2022 among participants > 2 years-old from across the US who enrolled using a smartphone app. During each testing encounter, participants self-collected one nasal swab and performed Ag-RDT at home; at-least fifteen minutes later, a second nasal swab was self-collected and shipped for SARS-CoV-2 RT-PCR at a central lab. Both nasal swabs were collected 7 times at 48-hour intervals (over approximately 14 days) followed by an extra nasal swab collection with home Ag-RDT test 48-hours after their last PCR sample. Each participant was assigned to one of the three emergency use authorized (EUA) Ag-RDT tests used in this study. This analysis was limited to participants who were asymptomatic and tested negative by antigen and molecular test on their first day of study participation. Exposure: SARS-CoV-2 positivity was determined by testing a single home-collected anterior nasal sample with three FDA EUA molecular tests, where 2 out 3 positive test results were needed to determine a SARS-CoV-2 positive result. Onset of infection was defined as day on which the molecular PCR comparator result was positive for the first time. Main outcomes and measures: Sensitivity of Ag-RDT was measured based on testing once (same-day), twice (at 48-hours) and thrice (at 96 hours). Analysis was repeated for different Days Post Index PCR Positivity (DPIPP) and stratified based on symptom-status on a given DPIPP. Results: A total of 7,361 participants enrolled in the study and 5,609 were eligible for this analysis. Among 154 eligible participants who tested positive for SARS-CoV-2 infection based on RT-PCR, 97 were asymptomatic and 57 had symptoms at onset of infection (DPIPP 0). Serial testing with Ag-RDT twice over 48-hours resulted in an aggregated sensitivity of 93.4% (95% CI: 89.1-96.1%) among symptomatic participants on DPIPP 0-6. Among the 97 people who were asymptomatic at the onset of infection, 19 were singleton RT-PCR positive, i.e., their positive test was preceded and followed by a negative RT-PCR test within 48-hours. Excluding these singleton positives, aggregated sensitivity on DPIPP 0-6 for two-time serial-testing among asymptomatic participants was lower 62.7% (54.7-70.0%) but improved to 79.0% (71.0-85.3%) with serial testing three times at 48-hour interval. Discussion: Performance of Ag-RDT within first week of infection was optimized when asymptomatic participants tested three-times at 48-hour intervals and when symptomatic participants tested two-times separated by 48-hours.
    • Finding a Needle in the Haystack: Design and Implementation of a Digital Site-less Clinical Study of Serial Rapid Antigen Testing to Identify Asymptomatic SARS-CoV-2 Infection [preprint]

      Soni, Apurv; Herbert, Carly; Pretz, Caitlin; Stamegna, Pamela; Filippaios, Andreas; Shi, Qiming; Suvarna, Thejas; Harman, Emma; Schrader, Summer; Nowak, Chris; et al. (2022-08-05)
      Background: Over-the-counter rapid antigen tests for SARS-CoV-2 with an Emergency Use Authorization (EUA) in the United States generally include a condition of authorization to evaluate the test's performance in asymptomatic individuals when used serially. A goal of this study was to investigate the performance of SARS-CoV-2 antigen serial testing and generate data to support regulatory decisions. Objective: To describe a novel study design to evaluate serial use of rapid antigen tests in detecting SARS-CoV-2 virus among asymptomatic individuals. Design: Prospective cohort study using a decentralized approach. Eligible participants from across the U.S. could enroll and complete this study from their home environment through a study app. Participant enrollment was prioritized based on regional 7-day case rates, participants' vaccination status, and sociodemographic characteristics prior to enrollment.Prioritization criteria were adjusted on a daily or weekly basis. Enrolled participants were mailed rapid antigen tests and molecular comparator collection kits and asked to test every 48 hours for 15 days. Three companies' rapid antigen tests were used in the study; assignment of participant to a test was criteria-based and non-random, precluding head-to-head comparison between the tests. Participants: Mainland United States residents over 2 years old with no reported COVID-19 symptoms in the 14 days prior to study enrollment. Main measures: Participant demographics, COVID-19 vaccination status, and geographic distribution were used to understand the impact of the site-less recruitment and enrollment strategy. Key results: A total of 7,361 participants enrolled in the study between October 18, 2021 and February 15, 2022. Throughout the study, 369 participants tested positive for SARS-CoV-2, including 167 who were asymptomatic and tested negative on SARS-CoV-2 molecular assays to start the study. This exceeded the initial enrollment goals of 60 positive participants. We enrolled participants from 44 of the 48 mainland U.S. states, and geographic distribution of participants shifted in accordance with the changing COVID-19 prevalence nationwide. Conclusions: The novel, digital site-less approach employed in the 'Test Us At Home' study enabled rapid, efficient, and rigorous evaluation of rapid diagnostics for COVID-19, and can be adapted across research disciplines to optimize study enrollment and accessibility.
    • Use of a Digital Assistant to Report COVID-19 Rapid Antigen Self-test Results to Health Departments in 6 US Communities

      Herbert, Carly; Shi, Qiming; Kheterpal, Vik; Nowak, Chris; Suvarna, Thejas; Durnan, Basyl; Schrader, Summer; Behar, Stephanie; Naeem, Syed; Tarrant, Seanan; et al. (2022-08-01)
      Importance: Widespread distribution of rapid antigen tests is integral to the US strategy to address COVID-19; however, it is estimated that few rapid antigen test results are reported to local departments of health. Objective: To characterize how often individuals in 6 communities throughout the United States used a digital assistant to log rapid antigen test results and report them to their local departments of health. Design, setting, and participants: This prospective cohort study is based on anonymously collected data from the beneficiaries of the Say Yes! Covid Test program, which distributed more than 3 000 000 rapid antigen tests at no cost to residents of 6 communities (Louisville, Kentucky; Indianapolis, Indiana; Fulton County, Georgia; O'ahu, Hawaii; Ann Arbor and Ypsilanti, Michigan; and Chattanooga, Tennessee) between April and October 2021. A descriptive evaluation of beneficiary use of a digital assistant for logging and reporting their rapid antigen test results was performed. Interventions: Widespread community distribution of rapid antigen tests. Main outcomes and measures: Number and proportion of tests logged and reported to the local department of health through the digital assistant. Results: A total of 313 000 test kits were distributed, including 178 785 test kits that were ordered using the digital assistant. Among all distributed kits, 14 398 households (4.6%) used the digital assistant, but beneficiaries reported three-quarters of their rapid antigen test results to their state public health departments (30 965 tests reported of 41 465 total test results [75.0%]). The reporting behavior varied by community and was significantly higher among communities that were incentivized for reporting test results vs those that were not incentivized or partially incentivized (90.5% [95% CI, 89.9%-91.2%] vs 70.5%; [95% CI, 70.0%-71.0%]). In all communities, positive tests were less frequently reported than negative tests (60.4% [95% CI, 58.1%-62.8%] vs 75.5% [95% CI, 75.1%-76.0%]). Conclusions and relevance: These results suggest that application-based reporting with incentives may be associated with increased reporting of rapid tests for COVID-19. However, increasing the adoption of the digital assistant may be a critical first step.
    • Validation of DREADD agonists and administration route in a murine model of sleep enhancement

      Ferrari, Loris L; Ogbeide-Latario, Oghomwen E; Gompf, Heinrich S; Anaclet, Christelle (2022-07-30)
      Chemogenetics is a powerful tool to study the role of specific neuronal populations in physiology and diseases. Of particular interest, in mice, acute and specific activation of parafacial zone (PZ) GABAergic neurons expressing the Designer Receptors Activated by Designer Drugs (DREADD) hM3Dq (PZGABA-hM3Dq) enhances slow-wave-sleep (SWS), and this effect lasts for up to 6 h, allowing prolonged and detailed study of SWS. However, the most widely used DREADDs ligand, clozapine N-oxide (CNO), is metabolized into clozapine which has the potential of inducing non-specific effects. In addition, CNO is usually injected intraperitoneally (IP) in mice, limiting the number and frequency of repeated administration.
    • High bacillary burden and the ESX-1 type VII secretion system promote MHC class I presentation to CD8 T-cells during Mycobacterium tuberculosis infection

      Mott, Daniel (2022-07-26)
      T-cell mediated immunity is required for optimal protection against Mycobacterium tuberculosis (Mtb) infection, but often fails to completely clear the pathogen. Mtb has evolved strategies to subvert host immunity so it can persist in host cells despite pressure from innate and adaptive immunity. While cytotoxic CD8 T-cells should recognize and clear infected host cells, eliminating Mtb’s intracellular niche, previous findings have demonstrated otherwise [1]. In fact, we have shown that CD8 T-cells specific to the immunodominant antigen TB10.4 poorly recognize Mtb infected macrophages in vitro. Here we extend our initial findings to show that class I MHC-restricted epitopes other than TB10.44-11 are inefficiently presented by Mtb-infected macrophages to CD8 T cells. The only exception we find is for heavily infected macrophages. During high burden infections, macrophages cross-present TB10.4 antigen to CD8 T-cells. These high burden infections result in considerable cell death, and we find that uninfected macrophages effectively scavenge dead cellular debris and cross-present this antigen to CD8 T cells. Furthermore, we find that cross-presentation by heavily infected cells is dependent on the ESX-1 type VII secretion system, suggesting that phagosomal membrane damage and host cell death are crucial for effective class I MHC cross-presentation during Mtb infection.
    • Healthcare use in commercially insured youth with mental health disorders

      Hugunin, Julie; Davis, Maryann; Larkin, Celine; Baek, Jonggyu; Skehan, Brian; Lapane, Kate L (2022-07-26)
      Background: The objective of this study is to describe age-related patterns of outpatient healthcare utilization in youth and young adults with mental health disorders. Method: We used the IBM® MarketScan® Commercial Database to identify 359,413 youth and young adults (12-27 years) with a mental health disorder continuously enrolled in private health insurance in 2018. Exploratory analysis was used to describe patterns of outpatient healthcare use (e.g., primary, reproductive, mental health care) and therapeutic management (e.g., medication prescriptions, psychotherapy) by age. Period prevalence and median number of visits are reported. Additional analysis explored utilization patterns by mental health disorder. Results: The prevalence of outpatient mental health care and primary care decreased with age, with a larger drop in primary care utilization. While 74.0-78.4% of those aged 12-17 years used both outpatient mental health care and primary care, 53.1-59.7% of those aged 18-27 years did. Most 18-19-year-olds had a visit with an internal medicine or family medicine specialist, a minority had a pediatrician visit. The prevalence of medication management increased with age, while the prevalence of psychotherapy decreased. Conclusions: Taken together, this descriptive study illustrates age-related differences in outpatient healthcare utilization among those with mental health disorders. Additionally, those with the most severe mental health disorders seem to be least connected to outpatient care. This knowledge can inform efforts to improve utilization of healthcare across the transition to adulthood.
    • Prevalence of Bipolar Disorder in Perinatal Women: A Systematic Review and Meta-Analysis

      Masters, Grace A; Hugunin, Julie; Xu, Lulu; Ulbricht, Christine M; Moore Simas, Tiffany A; Ko, Jean Y; Byatt, Nancy (2022-07-13)
      Objective: To estimate overall prevalence of bipolar disorder (BD) and the prevalence and timing of bipolar-spectrum mood episodes in perinatal women. Data Sources: Databases (PubMed, Scopus, PsycINFO, CINAHL, Cochrane, were searched from inception to March 2020. Study Selection: Included studies were original research in English that had (1) populations of perinatal participants (pregnant or within 12 months postpartum), aged ≥ 18 years, and (2) a screening/diagnostic tool for BD. Search terms described the population (eg, perinatal), illness (eg, bipolar disorder), and detection (eg, screen, identify). Data Extraction: Study design data, rates, and timing of positive screens/diagnoses and mood episodes were extracted by 3 independent reviewers. Pooled prevalences were estimated using random-effects meta-analyses. Results: Twenty-two articles were included in qualitative review and 12 in the meta-analysis. In women with no known psychiatric illness preceding the perinatal period, pooled prevalence of BD was 2.6% (95% CI, 1.2%-4.5%) and prevalence of bipolar-spectrum mood episodes (including depressed, hypomanic/manic, mixed) during pregnancy and the postpartum period was 20.1% (95% CI, 16.0%-24.5%). In women with a prior BD diagnosis, 54.9% (95% CI, 39.2%-70.2%) were found to have at least one bipolar-spectrum mood episode occurrence in the perinatal period. Conclusions: Our review suggests that the perinatal period is associated with high rates of bipolar-spectrum mood episodes and that pregnant and postpartum women represent a special risk population. This review may help to inform clinical care recommendations, thus helping to identify those who may have.
    • The Role of Age-Associated B Cells (ABC) in Combating Influenza Infection

      Kugler-Umana, Olivia (2022-07-12)
      With age, follicular helper T cell (TFH) dependent B cell responses erode, reducing B cell memory and long-term antibody responses. However, aged mice and humans develop an alternative B cell population, termed age-associated B cells (ABC), that may produce TFH independent antibodies. ABC lack CD21 and CD23 expression, and some express transcription factors and adhesion molecules indicative of antigen exposure. Some of these have been implicated in autoimmunity. We found a unique population of responding B cells following influenza A virus (IAV) infection, which was Fashi/GL7neg. We postulated that the CD21-CD23-ABC might be progenitors of these non-follicular B cells, that we called induced ABC (iABC). Using T-deficient RAG KO and TFH deficient SAP KO hosts, we found that the CD21-CD23-ABC can become iABC (FasHiGL7-) upon IAV infection. These iABC share the same phenotype of iABC found in infected aged mice and can become Ab-producing cells without T cell help. We showed that CD21-CD23-ABC can be separated into IgD+ (putative naïve B cells) vs. IgD- (memory-like B cells). We followed their ability to become iABC in SAP KO hosts. The IgD+ABC were most efficient at giving rise to iABC. Further transfer studies revealed that iABC generation from donor IgD+ABC requires extrinsic TLR signaling, and IgD+ABC can provide Ab-medicated protection. We concluded that upon T-independent stimulation, IgD+ABC (CD21-CD23-) become iABC (Fashi/GL7neg), some of which can secrete IAV-specific Ab and may provide protection against IAV.
    • Development and test-retest reliability of a screening tool for axial spondyloarthritis

      Shridharmurthy, Divya; Lapane, Kate L.; Khan, Sara; Yi, Esther; Baek, Jonggyu; Kay, Jonathan; Liu, Shao-Hsien (2022-07-08)
      Background: People with axial Spondyloarthritis (axSpA) suffer from lengthy diagnostic delays of ~7 years. The usage of screening tools to identify axSpA patients in primary care can reduce diagnostic delays by facilitating early referral to rheumatologic care. The purpose of this study was to examine the psychometric properties of a potential screening tool for patients with axSpA. Method: Content validity was evaluated by soliciting feedback from 7 rheumatologists regarding the relevance and content representativeness of the proposed screening questions. For the test-retest study, participants ≥18 years of age with chronic back pain (≥3 months) without a diagnosis of mechanical or inflammatory back pain (n = 91) were e-recruited through ResearchMatch. Participation included completing identical baseline and follow-up questionnaires ~14 days apart. Weighted quadratic kappa was used to measure test-retest reliability between the two ratings of the ordinal scales. Construct validity was examined using exploratory factor analysis (EFA) and items with factor loadings ≥0.6 were extracted. Scale dimensionality and simplified factorial solutions were measured using Kaiser's criteria (Eigenvalue >1). Cronbach's alpha was used to measure internal consistency. Results: Most participants were women, non-Hispanic white, and had at least some college education, with a mean age of 45 years. On average, the age at onset of back pain was 31 years. Eleven questions yielded test-retest reliabilities ranging from 0.6 to 0.76. Results from EFA extracted two factors relating to: 1) how pain affects daily life functioning and 2) whether pain improves with movement. Internal consistency was high for questions evaluating how pain affects life, with a Cronbach's alpha of 0.81. Following assessment for validity and reliability, the questionnaire was revised to create the 6-item screening tool. Conclusions: The 6-item SpA-SED screening tool designed to identify potential cases of axSpA was found to have good test-retest reliability and high internal consistency.
    • Novel Genetic Pathways in Functional Regulation of Hematopoietic Stem Cells

      Desouza, Ngoc (2022-07-08)
      Hematopoietic stem cells (HSCs) are a rare population of bone marrow cells that have self-renewal and differentiating capabilities enabling them to produce all blood lineages during normal hematopoiesis. Many molecular pathways are involved in the regulation of HSCs, and the survival, maintenance and proliferation of these cells must be tightly controlled to avoid aberrant activities that can cause blood diseases, such as hematopoietic malignancies. Therefore, additional factors involved in the functional regulation of HSCs must be discovered to provide new therapeutic treatments for hematopoietic diseases. In chapter I, I briefly introduce the hematopoietic system and hierarchy through which HSCs can produce all mature blood cells in the lifespan. I also describe various methods to identify different hematopoietic cells, with a focus on using cell surface antigen markers. I additionally discuss an important method to study HSCs in mice by using bone marrow transplantation in which the donor cells are manipulated to examine the role of a gene of interest. I also briefly describe several signaling pathways important in HSCs, such as the Bmp, Wnt, Hedgehog and Notch signaling pathways. I provide known relevant information to my thesis work on c-Kit and Sca-1 receptors, as well as on LSK and LSK- cells. In chapter II, I describe my findings regarding a novel mechanism in which Ikzf3 plays a suppressive role in regulating HSC survival and maintenance. Ikzf3 suppresses the population of LSK (lineage-Sca-1+c-Kit+) cells that contains HSCs, and increases the LSK- (lineage-Sca-1+c-Kit-) population, which is highly apoptotic and derived from the LSK population. The DNA binding domain of Ikzf3 is required for its inhibition of HSCs, and Ikzf3 downregulates the expression of Bcl-2, Bcl-xL and c-Myc. Ikzf3 expression in HSCs is maintained at low levels by the c-Kit pathway. In chapter III, on the basis of data from microarray analysis previously performed to compare gene expression profiles between Hif1a knockout HSCs and wild type HSCs, the effects of both Hif1a and Notch1 deletion on HSC regulation are examined. Loss of both Hif1a and Notch1 induces the development of myelodysplastic/myeloproliferative diseases, which are clonal hematopoietic stem cell neoplasms characterized by abnormal regulation of the myeloid pathways for cellular proliferation, maturation and survival. Loss of both Hif1a and Notch1 also leads to a loss of HSC function. These findings indicate a mechanism through which the hypoxia pathway acts in coordination with the Notch pathway in HSCs. In chapter IV, I summarize the findings from chapter II and III and discuss the importance of these results in the field. I also provide the future directions that can answer more questions to expand our knowledge on these pathways. Together, the findings reveal two novel pathways involved in functional regulation of HSCs: (i) the Ikzf3 pathway, which involves c-Kit, Icsbp, Bcl-2, Bcl-xL and c-Myc, and suppresses normal HSCs to maintain homeostasis and (ii) the synergy of Hif1a and Notch1 in regulating HSCs. The loss of both genes can cause myelodysplastic/myeloproliferative-like diseases.
    • COVID-19: a gray swan's impact on the adoption of novel medical technologies

      Dunlap, Denise; Santos, Roberto S.; Lilly, Craig M.; Teebagy, Sean; Hafer, Nathaniel S.; Buchholz, Bryan O.; McManus, David D. (2022-07-08)
      The COVID-19 pandemic offers a unique context and opportunity to investigate changes in healthcare professional perceptions towards the adoption of novel medical technologies, such as point-of-care technologies (POCTs). POCTs are a nascent technology that has experienced rapid growth as a result of COVID-19 due to their ability to increase healthcare accessibility via near-patient delivery, including at-home. We surveyed healthcare professionals before and during COVID-19 to explore whether the pandemic altered their perceptions about the usefulness of POCTs. Our network analysis method provided a structure for understanding this changing phenomenon. We uncovered that POCTs are not only useful for diagnosing COVID-19, but healthcare professionals also perceive them as increasingly important for diagnosing other diseases, such as cardiovascular, endocrine, respiratory, and metabolic diseases. Healthcare professionals also viewed POCTs as facilitating the humanization of epidemiology by improving disease management/monitoring and strengthening the clinician-patient relationship. As the accuracy and integration of these technologies into mainstream healthcare delivery improves, hurdles to their adoption dissipate, thereby encouraging healthcare professionals to rely upon them more frequently to diagnose, manage, and monitor diseases. The technological advances made in POCTs during COVID-19, combined with shifting positive perceptions of their utility by healthcare professionals, may better prepare us for the next pandemic.
    • Elevated TNF-α Leads to Neural Circuit Instability in the Absence of Interferon Regulatory Factor 8

      Feinberg, Philip A; Becker, Shannon C; Chung, Leeyup; Ferrari, Loris; Stellwagen, David; Anaclet, Christelle; Durán-Laforet, Violeta; Faust, Travis E; Sumbria, Rachita K; Schafer, Dorothy P. (2022-07-05)
      Interferon regulatory factor 8 (IRF8) is a transcription factor necessary for the maturation of microglia, as well as other peripheral immune cells. It also regulates the transition of microglia and other immune cells to a pro-inflammatory phenotype. Irf8 is also a known risk gene for multiple sclerosis and lupus, and it has recently been shown to be downregulated in schizophrenia. While most studies have focused on IRF8-dependent regulation of immune cell function, little is known about how it impacts neural circuits. Here, we show by RNAseq from Irf8 -/- male and female mouse brains that several genes involved in regulation of neural activity are dysregulated. We then show that these molecular changes are reflected in heightened neural excitability and a profound increase in susceptibility to lethal seizures in male and female Irf8 -/- mice. Finally, we identify that TNF-α is elevated specifically in microglia in the CNS, and genetic or acute pharmacological blockade of TNF-α in the Irf8 -/- CNS rescued the seizure phenotype. These results provide important insights into the consequences of IRF8 signaling and TNF-α on neural circuits. Our data further suggest that neuronal function is impacted by loss of IRF8, a factor involved in neuropsychiatric and neurodegenerative diseases.SIGNIFICANCE STATEMENT Here, we identify a previously unknown and key role for interferon regulator factor 8 (IRF8) in regulating neural excitability and seizures. We further determine that these effects on neural circuits are through elevated TNF-α in the CNS. As IRF8 has most widely been studied in the context of regulating the development and inflammatory signaling in microglia and other immune cells, we have uncovered a novel function. Further, IRF8 is a risk gene for multiple sclerosis and lupus, IRF8 is dysregulated in schizophrenia, and elevated TNF-α has been identified in a multitude of neurologic conditions. Thus, elucidating these IRF8 and TNF-α-dependent effects on brain circuit function has profound implications for understanding underlying, therapeutically relevant mechanisms of disease.
    • Cancer Prehabilitation in Practice: the Current Evidence

      Coderre, Danielle; Brahmbhatt, Priya; Hunter, Tracey Louise; Baima, Jennifer (2022-07-05)
      Purpose of Review This article serves to describe recent controversies in cancer prehabilitation including efficacy, dose, cost effectiveness, stakeholder input, and international implementation. Recent Findings Appropriate frequency, type, and timing have yet to be determined, but high intensity exercise is recommended. Costs are favorable when modeled and information on costs of real-world application are forthcoming. Patients are interested in and willing to attend cancer prehabilitation. Cancer prehabilitation research is spreading throughout the world. Summary Cancer prehabilitation includes assessment of a newly diagnosed cancer patient’s baseline fitness and targeted interventions to improve their health before surgery, chemotherapy, or radiation. Cancer prehabilitation improves fitness as measured preoperatively and improves outcomes postoperatively.
    • Social Connectedness among Long-Stay Nursing Home Residents with Alzheimer's and Dementia: Exploring Individual and Facility-Level Variation

      Lapane, Kate L; Dubé, Catherine E; Jesdale, Bill M; Bova, Carol (2022-07-04)
      Introduction: This study sought to explore individual and facility-level variation in social connectedness among long-stay nursing home residents with Alzheimer's or other dementias (ADRD). Methods: We identified 721,074 long-stay residents with ADRD using 2016 Minimum Data Set 3.0 data. Social connectedness was defined using the social connectedness index (SCI) (high: SCI = 5, lower: 0 < SCI ≤ 4). Adjusted odds ratios (aOR) provided estimates of the associations between resident-level and facility-level characteristics, and high SCI was derived from logistic models. Results: The SCI Cronbach's alpha was 0.69; 78.6% had high SCI scores. Men were less likely than women to have higher SCI scores (aOR = 0.97; 95% CI: 0.97-0.98). Increasing age was associated with higher SCI scores (e.g., aOR [85-94 vs. 40-64 years]: 1.07; 95% CI: 1.06-1.07). Those with moderate cognitive impairment (aOR: 0.87) and severe cognitive impairment (aOR: 0.85) had reduced odds of SCI = 5 relative to those with mild/intact cognitive function. Residents living in homes with special care dementia units and with higher percentage of residents with dementia had decreased odds of high social connectedness. Discussion/conclusion: Understanding resident- and nursing home-level variation in social connectedness may be important for targeting interventions that reduce isolation among residents with ADRD.
    • Gliotransmission Orchestrates Neuronal Type-specific Axon Regeneration

      Wang, Fei (2022-06-30)
      Why closely related neuronal types differ in their axon regenerative abilities remains elusive. Here, I demonstrate gliotransmission determines such a difference in Drosophila larval sensory neurons. Axotomy activates ensheathing glia, which signal to regenerative neurons through the gliotransmitter adenosine, to mount regenerative programs including neuronal activity and Ras. Surprisingly, ensheathing glia do not signal to non-regenerative neurons. Such neuronal type-specific responses to gliotransmission result from specific expression of adenosine receptors in regenerative neurons. Disrupting gliotransmission impedes regeneration of regenerative neurons. Strikingly, reconstitution of gliotransmission in non-regenerative neurons enables them to regenerate. Furthermore, activation of an adenosine receptor in adult mice promotes both regeneration and survival of retinal ganglion cells, uncovering a conserved pro-regenerative role of adenosine receptors. My studies demonstrate gliotransmission as a novel mechanism by which glia instruct axon regeneration, with neuronal type-specificity, and suggest targeting purinergic signaling as a new strategy for mammalian central nervous system repair.