UMB Digital Archive

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.

 

  • Defining Longer-Term Outcomes in an Ovine Model of Moderate Perinatal Hypoxia-Ischemia

    Mike, Jana Krystofova; Wu, Katherine Y.; White, Yasmine; Pathipati, Praneeti; Ndjamen, Blaise; Hutchings, Rachel S.; Losser, Courtney; Vento, Christian; Arellano, Kimberly; Vanhatalo, Oona; et al. (2022-01-01)
    Hypoxic-ischemic encephalopathy (HIE) is the leading cause of neonatal morbidity and mortality worldwide. Approximately 1 million infants born with HIE each year survive with cerebral palsy and/or serious cognitive disabilities. While infants born with mild and severe HIE frequently result in predictable outcomes, infants born with moderate HIE exhibit variable outcomes that are highly unpredictable. Here, we describe an umbilical cord occlusion (UCO) model of moderate HIE with a 6-day follow-up. Near-term lambs (n = 27) were resuscitated after the induction of 5 min of asystole. Following recovery, lambs were assessed to define neurodevelopmental outcomes. At the end of this period, lambs were euthanized, and brains were harvested for histological analysis. Compared with prior models that typically follow lambs for 3 days, the observation of neurobehavioral outcomes for 6 days enabled identification of animals that recover significant neurological function. Approximately 35% of lambs exhibited severe motor deficits throughout the entirety of the 6-day course and, in the most severely affected lambs, developed spastic diparesis similar to that observed in infants who survive severe neonatal HIE (severe, UCOs). Importantly, and similar to outcomes in human neonates, while initially developing significant acidosis and encephalopathy, the remainder of the lambs in this model recovered normal motor activity and exhibited normal neurodevelopmental outcomes by 6 days of life (improved, UCOi). The UCOs group exhibited gliosis and inflammation in both white and gray matters, oligodendrocyte loss, neuronal loss, and cellular death in the hippocampus and cingulate cortex. While the UCOi group exhibited more cellular death and gliosis in the parasagittal cortex, they demonstrated more preserved white matter markers, along with reduced markers of inflammation and lower cellular death and neuronal loss in Ca3 of the hippocampus compared with UCOs lambs. Our large animal model of moderate HIE with prolonged follow-up will help further define pathophysiologic drivers of brain injury while enabling identification of predictive biomarkers that correlate with disease outcomes and ultimately help support development of therapeutic approaches to this challenging clinical scenario.
  • Pre-operative Machine Learning for Heart Transplant Patients Bridged with Temporary Mechanical Circulatory Support †

    Shou, Benjamin L.; Chatterjee, Devina; Russel, Joseph W.; Zhou, Alice L.; Florissi, Isabella S.; Lewis, Tabatha; Verma, Arjun; Benharash, Peyman; Choi, Chun Woo (2022-09-01)
    Background: Existing prediction models for post-transplant mortality in patients bridged to heart transplantation with temporary mechanical circulatory support (tMCS) perform poorly. A more reliable model would allow clinicians to provide better pre-operative risk assessment and develop more targeted therapies for high-risk patients. Methods: We identified adult patients in the United Network for Organ Sharing database undergoing isolated heart transplantation between 01/2009 and 12/2017 who were supported with tMCS at the time of transplant. We constructed a machine learning model using extreme gradient boosting (XGBoost) with a 70:30 train:test split to predict 1-year post-operative mortality. All pre-transplant variables available in the UNOS database were included to train the model. Shapley Additive Explanations was used to identify and interpret the most important features for XGBoost predictions. Results: A total of 1584 patients were included, with a median age of 56 (interquartile range: 46–62) and 74% male. Actual 1-year mortality was 12.1%. Out of 498 available variables, 43 were selected for the final model. The area under the receiver operator characteristics curve (AUC) for the XGBoost model was 0.71 (95% CI: 0.62–0.78). The most important variables predictive of 1-year mortality included recipient functional status, age, pulmonary capillary wedge pressure (PCWP), cardiac output, ECMO usage, and serum creatinine. Conclusions: An interpretable machine learning model trained on a large clinical database demonstrated good performance in predicting 1-year mortality for patients bridged to heart transplantation with tMCS. Machine learning may be used to enhance clinician judgement in the care of markedly high-risk transplant recipients.
  • Enhanced neoepitope-specific immunity following neoadjuvant PD-L1 and TGF-β blockade in HPV-unrelated head and neck cancer

    Redman, Jason M.; Friedman, Jay; Robbins, Yvette; Sievers, Cem; Yang, Xinping; Lassoued, Wiem; Sinkoe, Andrew; Papanicolau-Sengos, Antonios; Lee, Chyi Chia; Marte, Jennifer L.; et al. (2022-09-15)
    Background. Head and neck squamous cell carcinoma not associated with HPV (HPV-unrelated HNSCC) is associated with a high rate of recurrence and poor survival. Methods. We conducted a clinical trial in 14 patients with newly diagnosed HPV-unrelated HNSCC to evaluate the safety and efficacy of neoadjuvant bintrafusp alfa, a bifunctional fusion protein that blocks programmed death ligand 1 (PD-L1) and neutralizes TGF-β. Results. Bintrafusp alfa was well tolerated, and no treatment-associated surgical delays or complications occurred. Objective pathologic responses (PRs) were observed, and 12 of the 14 (86%) patients were alive and disease free at 1 year. Alterations in Treg infiltration and spatial distribution relative to proliferating CD8+ T cells indicated a reversal of Treg immunosuppression in the primary tumor. Detection of neoepitope-specific tumor T cell responses, but not virus-specific responses, correlated with the development of a PR. Detection of neoepitope-specific responses and PRs in tumors was not correlated with genomic features or tumor antigenicity but was associated with reduced pretreatment myeloid cell tumor infiltration. These results indicate that dual PD-L1 and TGF-β blockade can safely enhance tumor antigen-specific immunity and highlight the feasibility of multimechanism neoadjuvant immunotherapy for patients with HPV-unrelated HNSCC. Conclusion. Our studies provide insight into the ability of neoadjuvant immunotherapy to induce polyclonal neoadjuvant- specific T cell responses in tumors and suggest that features of the tumor microenvironment, such as myeloid cell infiltration, may be a major determinant of enhanced antitumor immunity following such treatment.
  • Use of Transcarotid Artery Revascularization, Transfemoral Carotid Artery Stenting, and Carotid Endarterectomy in the US from 2015 to 2019

    Stonko, David P.; Goldsborough, Earl; Kibrik, Pavel; Zhang, George; Holscher, Courtenay M.; Hicks, Caitlin W. (2022-09-16)
    Importance: A transcarotid artery revascularization (TCAR) device was approved by the US Food and Drug Administration in 2015 for carotid revascularization in patients at high risk for stroke, cranial nerve injury, or major cardiac event. It is unclear how the introduction of TCAR has changed the use of carotid endarterectomy (CEA) and transfemoral carotid artery stenting (TFCAS). Objective: To quantify the temporal changes in the operative approach to carotid revascularization (CEA vs TFCAS vs TCAR), and to identify patient and disease characteristics commonly associated with each approach. Design, Setting, and Participants: This retrospective cohort study obtained data from the Vascular Quality Initiative database from January 1, 2015, to December 31, 2019. Patients with carotid artery stenosis who underwent CEA, TFCAS, or TCAR were included. Data were analyzed from January to April 2022. Exposures: Month and year of surgery as well as patient risk status. Main Outcomes and Measures: Number and proportion of carotid revascularization procedures by operative approach. Results: A total of 108676 patients (mean [SD] age 56.6 [12.5] years; 66 684 men [61.4%]) were included in the analysis. The most common operative approach overall was CEA (n = 81508 [75.0%]), followed by TFCAS (n = 15578 [14.3%]) and TCAR (n = 11590 [10.7%]). The number of procedures increased over the study period (16754 in 2015 vs 27269 in 2019; P <.001). In 2015, CEA was used in 84.9% of all cases, followed by TFCAS (14.4%) and TCAR (0.8%). In 2019, CEA was used in 64.8% of cases, followed by TCAR (21.9%) and TFCAS (13.3%). The proportional use of CEA decreased by 5.0% (95% CI, -7.4% to -2.6%) per year, and TCAR use increased by 5.3% (95% CI, 2.3%-8.3%) per year. Among patients at high risk, the change was greater: CEA use decreased by 7.8% (95% CI, -11.9% to -3.8%) per year, TFCAS decreased by 4.8% (95% CI, -9.5% to -0.14%) per year, and TCAR increased by 12.6% (95% CI, 7.1%-18.1%) per year. Multinomial logistic regression showed that patient risk status was the most important characteristic associated with TCAR compared with CEA (relative risk ratio, 36.10; 95% CI, 29.24-44.66; P <.001) and TFCAS (relative risk ratio, 14.10; 95% CI, 11.86-16.66; P <.001). Linear regression revealed no association between year of surgery and in-hospital myocardial infarction, stroke, or mortality. Conclusions and Relevance: Results of this study indicate that TCAR has become the dominant carotid revascularization approach, surpassing TFCAS and CEA in patients at high risk for stroke, cranial nerve injury, or cardiovascular events. Patient high-risk status was the main characteristic associated with a stenting approach, highlighting the perceived importance of carotid stenting therapies in this patient population.
  • Reframing the Conversation: Embracing Workplace Conflict Through a DEIB Lens

    Fosten-English, Mary; McNutt, Bryan R. (EAPA, 2022-10)
    While the experience of interpersonal conflict at work is not new, managers and EA professionals face increasingly complex and dynamic situations that influence how workplace conflict emerges, how conflict is interpreted, and how conflict is managed. Navigating workplace conflicts is often a part of the job that managers and employee assistance professionals report as a standard yet considerably challenging phenomenon in the workplace. In addition, organizational leaders are confronted with the dif- ficult task of guiding their teams through rapidly changing macro-sociocultural factors that can play out as unavoidable dynamics within the workplace, such as critical matters of diversity, equity, inclusion, and belonging (DEIB). This article discusses the intersectionality between workplace culture and conflict while also introducing the benefits of using a DEIB lens in navigating workplace conflict through the application of the EMBRACE© model of mediation.

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