Publications by authors named "Joshua D Hall"

Outcome data from 6 National Institutes of Health-funded Postbaccalaureate Research Education Programs (PREPs) in the Mid-Atlantic region were combined to give a multi-institutional perspective on their scholars' characteristics and progress through biomedical research training. The institutions hosting these programs were Johns Hopkins University School of Medicine, the Medical University of South Carolina, the University of Maryland School of Medicine, the University of North Carolina at Chapel Hill, Virginia Commonwealth University, and Virginia Polytechnic Institute and State University. The authors summarize the institutional pathways, demographics, undergraduate institutions, and graduate institutions for a total of 384 PREP scholars who completed the programs by June 2021.

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Lymphatic vessel contractions generate net antegrade pulsatile lymph flow. By contrast, impaired lymphatic vessels are often associated with lymphoedema and altered lymph flow. The effect of lymphoedema on the lymph flow field and endothelium is not completely known.

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Objective: Fluid shear stress (FSS) is known to mediate multiple phenotypic changes in the endothelium. Laminar FSS (undisturbed flow) is known to promote endothelial alignment to flow, which is key to stabilizing the endothelium and rendering it resistant to atherosclerosis and thrombosis. The molecular pathways responsible for endothelial responses to FSS are only partially understood.

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PhD-trained scientists are essential contributors to the workforce in diverse employment sectors that include academia, industry, government, and nonprofit organizations. Hence, best practices for training the future biomedical workforce are of national concern. Complementing coursework and laboratory research training, many institutions now offer professional training that enables career exploration and develops a broad set of skills critical to various career paths.

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Given national calls for intentional career development during graduate and post-graduate scientific training, this study assessed career readiness development within the context of academic career courses. The current study evaluated the effects of academic career courses offered at two institutions that were specifically designed to increase career awareness, interest, and career-related confidence among doctoral students and postdoctoral fellows. Participants enrolled in a career course at trainees' respective academic institutions and responded to pre- and post-course surveys (n=32, n=148).

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The lymphatic system plays a pivotal role in the transport of fats, waste, and immune cells, while also serving as a metastatic route for select cancers. Using live imaging and particle tracking, we experimentally characterized the lymph flow field distal from the inguinal lymph node in the vicinity of normal bileaflet and malformed unileaflet intraluminal valves. Particle tracking experiments demonstrated that intraluminal lymphatic valves concentrate higher velocity lymph flow in the center of the vessel, while generating adjacent perivalvular recirculation zones.

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Deep venous thrombosis (DVT) and secondary pulmonary embolism cause approximately 100,000 deaths per year in the United States. Physical immobility is the most significant risk factor for DVT, but a molecular and cellular basis for this link has not been defined. We found that the endothelial cells surrounding the venous valve, where DVTs originate, express high levels of FOXC2 and PROX1, transcription factors known to be activated by oscillatory shear stress.

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Recent studies using in vivo models have characterized lymph flow and demonstrated that lymph flow plays a key role in the later stages of lymphatic vascular development, including vascular remodeling, to create a hierarchical collecting vessel network and lymphatic valves (Sweet et al., J Clin Invest 125, 2995-3007, 2015). However, mechanistic insights into the response of lymphatic endothelial cells to fluid flow are difficult to obtain from in vivo studies because of the small size of lymphatic vessels and the technical challenge of lymphatic endothelial cell isolation.

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PhD recipients acquire discipline-specific knowledge and a range of relevant skills during their training in the life sciences, physical sciences, computational sciences, social sciences, and engineering. Empirically testing the applicability of these skills to various careers held by graduates will help assess the value of current training models. This report details results of an Internet survey of science PhDs (n = 8099) who provided ratings for fifteen transferrable skills.

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Many US biomedical PhD programs receive more applications for admissions than they can accept each year, necessitating a selective admissions process. Typical selection criteria include standardized test scores, undergraduate grade point average, letters of recommendation, a resume and/or personal statement highlighting relevant research or professional experience, and feedback from interviews with training faculty. Admissions decisions are often founded on assumptions that these application components correlate with research success in graduate school, but these assumptions have not been rigorously tested.

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A national sample of PhD-trained scientists completed training, accepted subsequent employment in academic and nonacademic positions, and were queried about their previous graduate training and current employment. Respondents indicated factors contributing to their employment decision (e.g.

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Certain racial and ethnic groups, individuals with disabilities, and those from low socioeconomic backgrounds remain underrepresented (UR) in the biomedical sciences. This underrepresentation becomes more extreme at each higher education stage. To support UR scholars during the critical transition from baccalaureate to PhD, we established an intensive, 1-yr postbaccalaureate training program.

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The highly pathogenic Yersinia enterocolitica strains have a chromosomally encoded type III secretion system (T3SS) that is expressed and functional in vitro only when the bacteria are cultured at 26 °C. Mutations that render this system nonfunctional are slightly attenuated in the mouse model of infection only following an oral inoculation and only at early time points postinfection. The discrepancy between the temperature required for the Ysa gene expression and the physiological temperature required for mammalian model systems has made defining the role of this T3SS challenging.

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Staphylococcus aureus is a dangerous pathogen that can cause necrotizing infections characterized by massive inflammatory responses and tissue destruction. Staphylococcal α-hemolysin is an essential virulence factor in severe S. aureus pneumonia.

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Fat infiltration and inflammation cause liver injury and fibrosis and may progress to nonalcoholic steatohepatitis (NASH) and end-stage liver disease. Currently, there are no effective treatments for NASH. Zeaxanthin is a carotenoid which has been shown to be preferentially accumulated in the adipose tissue and liver.

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Francisella tularensis causes systemic disease in humans and other mammals, with high morbidity and mortality associated with inhalation-acquired infection. F. tularensis is a facultative intracellular pathogen, but the scope and significance of cell types infected during disease is unknown.

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Francisella tularensis is a highly virulent bacterial pathogen that invades and replicates within numerous host cell types, including macrophages and epithelial cells. In an effort to better understand this process, we screened a transposon insertion library of the F. tularensis live vaccine strain (LVS) for mutant strains that invaded but failed to replicate within alveolar epithelial cell lines.

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Adaptation to the acidic microenvironment, and adherence to mucosal epithelium, are essential for persistent colonization of the human stomach by Helicobacter pylori. The expression of SabA, an adhesin implicated in the ability of H. pylori to adhere to the host gastric epithelium, can be modulated by phase variation via slipped-strand mispairing in repetitive nucleotide tracts located in both the promoter region and the coding region.

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Objectives: Lymph nodes normally have prominent centrally located blood vessels, which may become obliterated with tumor infiltration. The presence of intranodal vasculature has been noted to coincide with benign cytology. We sought to determine the test characteristics of the presence of intranodal mediastinal vasculature during endoscopic ultrasound (EUS).

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Francisella tularensis, a gram-negative facultative intracellular bacterial pathogen, causes disseminating infections in humans and other mammalian hosts. Macrophages and other monocytes have long been considered the primary site of F. tularensis replication in infected animals.

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Background: Management of biliary leaks includes ERCP and stent placement. The ability to temporarily place a partially covered self-expandable metallic stent (CSEMS) might offer an advantage in the treatment of biliary leaks.

Objective: We analyzed our 2 years' experience when using this innovative technique.

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Francisella tularensis replicates in macrophages and dendritic cells, but interactions with other cell types have not been well described. F. tularensis LVS invaded and replicated within alveolar epithelial cell lines.

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The diagnosis of bezoar formation may be difficult secondary to the nonspecific clinical presentation. Once a diagnosis is reached, the clinician has many options for management. These management options are largely based on the size and composition of the bezoar along with the experience or preference of the operator.

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Francisella tularensis is a highly virulent zoonotic bacterial pathogen capable of infecting numerous different mammalian species, including humans. Elucidation of the pathogenic mechanisms of F. tularensis has been hampered by a lack of tools to genetically manipulate this organism.

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Objectives: Limited data exist as to the reasons patients have for deciding among potentially curative treatment choices in clinically localized prostate cancer. Therefore, we carried out a descriptive pilot study to determine such motivations, sources of information, and other variables that influence how such patients choose between radical prostatectomy (RP) and brachytherapy (BT).

Methods: Three hundred fifty-one men with clinically localized Stage T1c-T3 adenocarcinoma of the prostate were treated by RP or palladium-103 BT, either alone (BTM) or in combination with external radiotherapy (BTC).

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