Scholarship & History

The UMB Digital Archive is a service of the Health Sciences and Human Services Library (HS/HSL) that collects, preserves, and distributes the academic works of the University of Maryland, Baltimore. It is a place that digitally captures the historical record of the campus.

 

  • Repeated sampling facilitates within- and between-subject modeling of the human sperm transcriptome to identify dynamic and stress-responsive sncRNAs

    Morgan, Christopher P; Shetty, Amol C; Chan, Jennifer C; Berger, Dara S; Ament, Seth A; Epperson, C Neill; Bale, Tracy L (Springer Nature, 2020-10-15)
    Epidemiological studies from the last century have drawn strong associations between paternal life experiences and offspring health and disease outcomes. Recent studies have demonstrated sperm small non-coding RNA (sncRNA) populations vary in response to diverse paternal insults. However, for studies in retrospective or prospective human cohorts to identify changes in paternal germ cell epigenetics in association with offspring disease risk, a framework must first be built with insight into the expected biological variation inherent in human populations. In other words, how will we know what to look for if we don’t first know what is stable and what is dynamic, and what is consistent within and between men over time? From sperm samples from a ‘normative’ cohort of healthy human subjects collected repeatedly from each subject over 6 months, 17 healthy male participants met inclusion criteria and completed donations and psychological evaluations of perceived stress monthly. sncRNAs (including miRNA, piRNA, and tRNA) isolated from mature sperm from these samples were subjected to Illumina small RNA sequencing, aligned to subtype-specific reference transcriptomes, and quantified. The repeated measures design allowed us to define both within- and between-subject variation in the expression of 254 miRNA, 194 tRNA, and 937 piRNA in sperm over time. We developed screening criteria to identify a subset of potential environmentally responsive ‘dynamic’ sperm sncRNA. Implementing complex modeling of the relationships between individual dynamic sncRNA and perceived stress states in these data, we identified 5 miRNA (including let-7f-5p and miR-181a-5p) and 4 tRNA that are responsive to the dynamics of prior stress experience and fit our established mouse model. In the current study, we aligned repeated sampling of human sperm sncRNA expression data with concurrent measures of perceived stress as a novel framework that can now be applied across a range of studies focused on diverse environmental factors able to influence germ cell programming and potentially impact offspring development. © 2020, The Author(s).
  • Endovascular model of ischemic stroke in swine guided by real-time MRI

    Golubczyk, D; Kalkowski, L; Kwiatkowska, J; Zawadzki, M; Holak, P; Glodek, J; Milewska, K; Pomianowski, A; Janowski, M; Adamiak, Z; et al. (Springer Nature, 2020-10-14)
    Modeling stroke in animals is essential for testing efficacy of new treatments; however, previous neuroprotective therapies, based on systemic delivery in rodents failed, exposing the need for model with improved clinical relevance. The purpose of this study was to develop endovascular approach for inducing ischemia in swine. To achieve that goal, we used intra-arterial administration of thrombin mixed with gadolinium and visualized the occlusion with real-time MRI. Placement of the microcatheter proximally to rete allowed trans-catheter perfusion of the ipsilateral hemisphere as visualized by contrast-enhanced perfusion MR scans. Dynamic T2*w MRI facilitated visualization of thrombin + Gd solution transiting through cerebral vasculature and persistent hyperintensities indicated occlusion. Area of trans-catheter perfusion dynamically quantified on representative slice before and after thrombin administration (22.20 ± 6.31 cm2 vs. 13.28 ± 4.71 cm2 respectively) indicated significantly reduced perfusion. ADC mapping showed evidence of ischemia as early as 27 min and follow-up T2w scans confirmed ischemic lesion (3.14 ± 1.41 cm2). Animals developed contralateral neurological deficits but were ambulatory. Our study has overcome long lasting challenge of inducing endovascular stroke model in pig. We were able to induce stroke using minimally invasive endovascular approach and observe in real-time formation of the thrombus, blockage of cerebral perfusion and eventually stroke lesion.
  • Improving Access and Quality of Health Care in the United States: Shared Goals Among Patient Advocates

    Oehrlein, Elisabeth M; Harris, Jason; Balch, Alan; Furlong, Pat; Hargis, Eric; Woolley, Mary; Perfetto, Eleanor (Adis, 2020-10-21)
  • Novel dose–response analyses of treprostinil in pulmonary arterial hypertension and its effects on six-minute walk distance and hospitalizations

    Ramani, Gautam; Cassady, Steven; Shen, Eric; Broderick, Meredith; Wasik, Allie; Sui, Qun; Nelsen, Andrew (SAGE Publications Inc., 2020-01-01)
    Treprostinil is a prostacyclin analogue approved for the treatment of pulmonary arterial hypertension. Apart from the inhaled formulation, there is neither a target dose nor a ceiling dose to guide clinicians using treprostinil; doses are individualized for each patient based upon tolerability and clinical improvement. Using combined data from the pivotal subcutaneous and oral treprostinil studies, we evaluated the effect of treprostinil dose on hospitalization and exercise capacity to better define the treprostinil dose–response relationship. Data from the pivotal subcutaneous and oral treprostinil studies were combined by converting oral doses to weight-based continuous doses (ng/kg/min) accounting for patient weight and bioavailability. Patients were divided into dose tertiles (lowest, middle, highest 33%) and retrospectively analyzed. Analysis 1 assessed the effect of dose on pulmonary arterial hypertension-related and all-cause hospitalizations. Analysis 2 evaluated the effects of dose on six-minute walk distance, Borg dyspnea score, and World Health Organization functional class. Results showed that, in Analysis 1, higher doses of treprostinil were associated with significantly longer times to first pulmonary arterial hypertension-related and all-cause hospitalization. In Analysis 2, there was a trend toward improvements in six-minute walk distance with higher doses. In patients with pulmonary arterial hypertension on systemic treprostinil therapy, higher doses were associated with significantly longer time to first pulmonary arterial hypertension-related and all-cause hospitalization. There was a trend toward improvements in six-minute walk distance. Collectively, these results underscore the importance of managing prostacyclin adverse events in order to achieve appropriate dose titration. Further studies are required to confirm these findings and to better characterize the dose–response relationship of treprostinil. © The Author(s) 2020.
  • Advances in hepatitis B therapeutics

    Soriano, Vicente; Barreiro, Pablo; Cachay, Edward; Kottilil, Shyamasundaran; Fernandez-Montero, José V.; de Mendoza, Carmen (SAGE Publications Inc., 2020-01-01)
    Despite the availability of both effective preventive vaccines and oral antivirals, over 250 million people are chronically infected with the hepatitis B virus (HBV). Globally, chronic hepatitis B is the leading cause of hepatocellular carcinoma, which represents the third cause of cancer mortality, accounting for nearly 1 million annual deaths. Current oral nucleos(t)ide therapy with tenofovir or entecavir suppresses serum HBV-DNA in most treated patients, but rarely is accompanied by HBsAg loss. Thus, treatment has to be given lifelong to prevent viral rebound. A broad spectrum of antivirals that block the HBV life cycle at different steps are in clinical development, including entry inhibitors, cccDNA disrupters/silencers, translation inhibitors, capsid assembly modulators, polymerase inhibitors and secretion inhibitors. Some of them exhibit higher potency than current oral nucleos(t)ides. Drugs in more advanced stages of clinical development are bulevirtide, JNJ-6379, ABI-H0731, ARO-HBV and REP-2139. To date, only treatment with ARO-HBV and with REP-2139 have resulted in HBsAg loss in a significant proportion of patients. Combination therapies using distinct antivirals and/or immune modulators are expected to maximize treatment benefits. The current goal is to achieve a ‘functional cure’, with sustained serum HBsAg after drug discontinuation. Ultimately, the goal of HBV therapy will be virus eradication, an achievement that would require the elimination of the cccDNA reservoir within infected hepatocytes. © The Author(s), 2020.

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