Browsing by Author "Davis, Michael D."
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Item 2020 Year in Review: Pharmacologic Treatments for COVID-19(2021-04) Saunders, Jessica L.; Davis, Michael D.; Pediatrics, School of MedicineCOVID-19, caused by SARS-CoV-2 infection, has led to a pandemic of acute respiratory illness. Pharmacologic treatments for COVID-19 have included treatments targeting infection prevention, prevention of viral replication, reducing inflammation and managing symptoms of respiratory failure caused by the disease. This is a review of key pharmacologic treatments for COVID-19 based on peer-reviewed articles from 2020.Item Antigen stasis and airway nitrosative stress in human primary ciliary dyskinesia(American Physiological Society, 2024) Gaston, Benjamin; Smith, Laura A.; Davis, Michael D.; Saunders, Jessica; Daniels, Ivana; Horani, Amjad; Brody, Steven L.; Giddings, Olivia; Zhao, Yi; Marozkina, Nadzeya; Pediatrics, School of MedicineNasal nitric oxide (nNO) is low in most patients with primary ciliary dyskinesia (PCD). Decreased ciliary motion could lead to antigen stasis, increasing oxidant production and NO oxidation in the airways. This could both decrease gas phase NO and increase nitrosative stress. We studied primary airway epithelial cells from healthy controls (HCs) and patients with PCD with several different genotypes. We measured antigen clearance in fenestrated membranes exposed apically to the fluorescently labeled antigen Dermatophagoides pteronyssinus (Derp1-f). We immunoblotted for 3-nitrotyrosine (3-NT) and for oxidative response enzymes. We measured headspace NO above primary airway cells without and with a PCD-causing genotype. We measured nNO and exhaled breath condensate (EBC) H2O2 in vivo. Apical Derp1-f was cleared from HC better than from PCD cells. DUOX1 expression was lower in HC than in PCD cells at baseline and after 24-h Derp1-f exposure. HC cells had less 3-NT and NO3- than PCD cells. However, NO consumption by HC cells was less than that by PCD cells; NO loss was prevented by superoxide dismutase (SOD) and by apocynin. nNO was higher in HCs than in patients with PCD. EBC H2O2 was lower in HC than in patients with PCD. The PCD airway epithelium does not optimally clear antigens and is subject to oxidative and nitrosative stress. Oxidation associated with antigen stasis could represent a therapeutic target in PCD, one with convenient monitoring biomarkers. NEW & NOTEWORTHY: The PCD airway epithelium does not optimally clear antigens, and antigen exposure can lead to NO oxidation and nitrosative stress. Oxidation caused by antigen stasis could represent a therapeutic target in PCD, and there are convenient monitoring biomarkers.Item Benefits of Airway Androgen Receptor Expression in Human Asthma(American Thoracic Society, 2021) Zein, Joe G.; McManus, Jeffrey M.; Sharifi, Nima; Erzurum, Serpil C.; Marozkina, Nadzeya; Lahm, Timothy; Giddings, Olivia; Davis, Michael D.; DeBoer, Mark D.; Comhair, Suzy A.; Bazeley, Peter; Kim, Hyun Jo; Busse, William; Calhoun, William; Castro, Mario; Chung, Kian Fan; Fahy, John V.; Israel, Elliot; Jarjour, Nizar N.; Levy, Bruce D.; Mauger, David T.; Moore, Wendy C.; Ortega, Victor E.; Peters, Michael; Bleecker, Eugene R.; Meyers, Deborah A.; Zhao, Yi; Wenzel, Sally E.; Gaston, Benjamin; Biostatistics, School of Public HealthRationale: Androgens are potentially beneficial in asthma, but AR (androgen receptor) has not been studied in human airways. Objectives: To measure whether AR and its ligands are associated with human asthma outcomes. Methods: We compared the effects of AR expression on lung function, symptom scores, and fractional exhaled nitric oxide (FeNO) in adults enrolled in SARP (Severe Asthma Research Program). The impact of sex and of androgens on asthma outcomes was also evaluated in the SARP with validation studies in the Cleveland Clinic Health System and the NHANES (U.S. National Health and Nutrition Examination Survey).Measurements and Main Results: In SARP (n = 128), AR gene expression from bronchoscopic epithelial brushings was positively associated with both FEV1/FVC ratio (R2 = 0.135, P = 0.0002) and the total Asthma Quality of Life Questionnaire score (R2 = 0.056, P = 0.016) and was negatively associated with FeNO (R2 = 0.178, P = 9.8 × 10-6) and NOS2 (nitric oxide synthase gene) expression (R2 = 0.281, P = 1.2 × 10-10). In SARP (n = 1,659), the Cleveland Clinic Health System (n = 32,527), and the NHANES (n = 2,629), women had more asthma exacerbations and emergency department visits than men. The levels of the AR ligand precursor dehydroepiandrosterone sulfate correlated positively with the FEV1 in both women and men. Conclusions: Higher bronchial AR expression and higher androgen levels are associated with better lung function, fewer symptoms, and a lower FeNO in human asthma. The role of androgens should be considered in asthma management.Item Blood Biomarkers for Detection of Brain Injury in COVID-19 Patients(Mary Ann Liebert, 2021) DeKosky, Steven T.; Kochanek, Patrick M.; Valadka, Alex B.; Clark, Robert S. B.; Chou, Sherry H. Y.; Au, Alicia K.; Horvat, Christopher; Jha, Ruchira M.; Mannix, Rebekah; Wisniewski, Stephen R.; Wintermark, Max; Rowell, Susan E.; Welch, Robert D.; Lewis, Lawrence; House, Stacey; Tanzi, Rudolph E.; Smith, Darci R.; Vittor, Amy Y.; Denslow, Nancy D.; Davis, Michael D.; Glushakova, Olena Y.; Hayes, Ronald L.; Pediatrics, School of MedicineThe severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus attacks multiple organs of coronavirus disease 2019 (COVID-19) patients, including the brain. There are worldwide descriptions of neurological deficits in COVID-19 patients. Central nervous system (CNS) symptoms can be present early in the course of the disease. As many as 55% of hospitalized COVID-19 patients have been reported to have neurological disturbances three months after infection by SARS-CoV-2. The mutability of the SARS-COV-2 virus and its potential to directly affect the CNS highlight the urgency of developing technology to diagnose, manage, and treat brain injury in COVID-19 patients. The pathobiology of CNS infection by SARS-CoV-2 and the associated neurological sequelae of this infection remain poorly understood. In this review, we outline the rationale for the use of blood biomarkers (BBs) for diagnosis of brain injury in COVID-19 patients, the research needed to incorporate their use into clinical practice, and the improvements in patient management and outcomes that can result. BBs of brain injury could potentially provide tools for detection of brain injury in COVID-19 patients. Elevations of BBs have been reported in cerebrospinal fluid (CSF) and blood of COVID-19 patients. BB proteins have been analyzed in CSF to detect CNS involvement in patients with infectious diseases, including human immunodeficiency virus and tuberculous meningitis. BBs are approved by the U.S. Food and Drug Administration for diagnosis of mild versus moderate traumatic brain injury and have identified brain injury after stroke, cardiac arrest, hypoxia, and epilepsy. BBs, integrated with other diagnostic tools, could enhance understanding of viral mechanisms of brain injury, predict severity of neurological deficits, guide triage of patients and assignment to appropriate medical pathways, and assess efficacy of therapeutic interventions in COVID-19 patients.Item Effectiveness of a short-term oxygen therapy training program in Liberia during and after COVID-19(Frontiers Media, 2025-02-12) Luke, Mark B.; Ziah, Moses, II; Lu, Lily Zhi Ning; Davis, Michael D.; Arzoaquoi, Samson; Drucker, Eva; Kanneh, Foday; Logan, Gorbee G.; Massaquoi, Moses; Pediatrics, School of MedicineBackground: Access to high-quality medical oxygen has been a long-standing challenge in Liberia due to barriers that span across the health system, which were amplified during the COVID-19 pandemic. The surge in cases requiring oxygen therapy necessitated rapid capacity-building for healthcare workers. In response, an emergency oxygen training package was adapted and implemented by the Liberia Ministry of Health and the National Incidence Management System. This manuscript evaluates the implementation of a short-term respiratory care training package to rapidly build healthcare worker capacity during the COVID-19 response and its adaptation for routine in-service training post-response. Methods: The emergency training used the "hot and cold" simulation approach from the 2014 Ebola response, consisting of a cold phase (3-days) with didactic lectures and practical sessions, and mock COVID treatment unit simulations (2-days); and a hot phase within an active CTU. Participants were doctors, physician assistants, nurses, or midwives, deployed to COVID treatment units at major health centers and hospitals across all counties in Liberia. Training assessments consisted of a paper-based knowledge test pre- and post-training, and Objective Structured Clinical Examinations post-training. Results: The emergency training as part of COVID response included 123 health care workers from 43 health facilities and saw a significant increase in knowledge (median score of 46% pre-training vs. 84% post-training, p < 0.001). Adaptation and piloting of the package for routine in-service training was also effective at increasing knowledge amongst 81 health care workers (median score of 41% pre-training vs. 78% post-training, p < 0.001). High post-training Objective Structured Clinical Examination scores demonstrated clinical competency achievement in both cohorts. For emergency training, median scores were 92% (pulse oximetry), 81% (oxygen cylinders), and 83% (oxygen concentrators). For routine in-service training, scores were 88, 82, and 84%, respectively. Conclusion: We demonstrate that the implementation of a healthcare worker training package in oxygen therapy during the COVID response in Liberia and its eventual integration into a routine in-service training program was able to achieve significant improvements in health care worker knowledge and skills. This highlights the feasibility of using rapid and short-term training to enhance clinical capacity within both emergency and post-response settings in a resource-limited country.Item Effects of pH alteration on respiratory syncytial virus in human airway epithelial cells(European Respiratory Society, 2023-07-03) Saunders, Jessica L.; Daniels, Ivana A.; Edwards, Taiya L.; Relich, Ryan F.; Zhao, Yi; Smith, Laura A.; Gaston, Benjamin M.; Davis, Michael D.; Pediatrics, School of MedicineBackground: Respiratory syncytial virus (RSV) is a leading cause of respiratory distress and hospitalisation in the paediatric population. Low airway surface pH impairs antimicrobial host defence and worsens airway inflammation. Inhaled Optate safely raises airway surface pH in humans and raises intracellular pH in primary human airway epithelial cells (HAECs) in vitro. We aimed to determine whether raising intracellular pH with Optate would decrease infection and replication of RSV in primary HAECs. Methods: We cultured HAECs from healthy subjects in both air-liquid interface and submerged conditions. We infected HAECs with green fluorescent protein-labelled RSV (GFP-RSV; multiplicity of infection=1) and treated them with Optate or PBS control. We collected supernatant after a 4-h incubation and then every 24 h. We used fluorescence intensity, fluorescent particle counts, plaque assays, Western blots and ELISA to quantitate infection. Results: In submerged culture, fluorescence intensity decreased in Optate-treated cells (48 h p=0.0174, 72 h p≤0.001). Similarly, Optate treatment resulted in decreased fluorescent particle count (48 h p=0.0178, 72 h p=0.0019) and plaque-forming units (48 h p=0.0011, 72 h p=0.0148) from cell culture supernatant. In differentiated HAECs cultured at ALI, Optate treatment decreased fluorescence intensity (p≤0.01), GFP via Western blot and ELISA (p<0.0001), and RSV-fusion protein via ELISA (p=0.001). Additionally, RSV infection decreased as Optate concentration increased in a dose-dependent manner (p<0.001). Conclusions: Optate inhibits RSV infection in primary HAECs in a dose-dependent manner. These findings suggest that Optate may have potential as an inhaled therapeutic for patients with RSV.Item Exhaled breath condensate biomarkers in critically ill, mechanically ventilated patients(IOP, 2020-11-12) Davis, Michael D.; Winters, Brett R.; Madden, Michael C.; Pleil, Joachim D.; Sessler, Curtis N.; Wallace, M. Ariel Geer; Ward-Caviness, Cavin K.; Montpetit, Alison J.; Pediatrics, School of MedicinePneumonia is a significant risk for critically ill, mechanically ventilated (CIMV) patients. Diagnosis of pneumonia generally requires a combination of clinician-guided diagnoses and clinical scoring systems. Exhaled breath condensate (EBC) can be safely collected non-invasively from CIMV patients. Hundreds of biomarkers in EBC are associated with acute disease states, including pneumonia. We evaluated cytokines in EBC from CIMV patients and hypothesized that these biomarkers would correlate with disease severity in pneumonia, sepsis, and death. EBC IL-2 levels were associated with chest radiograph severity scores (odds ratio = 1.68; 95% confidence interval = 1.09-2.60; P = 0.02). EBC TNF-α levels were also associated with pneumonia (odds ratio = 3.20; 95% confidence interval = 1.19-8.65; P = 0.02). The techniques and results from this study may be useful for all mechanically ventilated patients.Item In vitro-in vivo correlation of aerosol deposition before and after metered-dose inhaler coaching in healthy children(IOP, 2023) Davis, Michael D.; Saunders, Jessica L.; Ringer, Coral; Engberg, Rebecca; Zhao, Yi; DiBlasi, Rob; Rubin, Bruce K.; Pediatrics, School of MedicineAlthough pressurized metered dose inhaler (pMDI) education is a routine part of childhood asthma management and encouraging 'optimal breathing patterns' (i.e. slowly, deeply, completely, and with a mouth seal on the mouthpiece) is an integral part of recommended pMDI education, there is currently no quantifiable way to determine if a child is inhaling their medication correctly or optimally through a valved holding chamber (VHC). The TipsHaler™ (tVHC) is a prototype VHC device that measures inspiratory time, flow, and volume without changing the properties of the medication aerosol. The measurements in vivo recorded by the tVHC can be downloaded and transferred to a spontaneous breathing lung model to simulate the inhalational patterns in vitro and also determine the deposition of inhaled aerosol mass with each pattern. We hypothesized that pediatric patients' inhalational patterns when using a pMDI would improve after active coaching via tVHC. This would increase the pulmonary deposition of inhaled aerosols in an in vitro model. To test this hypothesis, we conducted a single-site, prospective, pilot, pre-and-post intervention study paired with a bedside-to-bench experiment. Healthy, inhaler-naïve subjects used a placebo inhaler in conjunction with the tVHC before and after coaching and recorded inspiratory parameters. These recordings were then implemented into a spontaneous breathing lung model during albuterol MDI delivery, and pulmonary deposition of albuterol was quantified. In this pilot study, active coaching resulted in a statistically significant increase in inspiratory time (n = 8, p= 0.0344, 95%CI: 0.082 to ∞). tVHC recorded inspiratory parameters obtained from patients were successfully implemented in the in vitro model, which demonstrated that both inspiratory time (n = 8, r = 0.78, p < 0.001, 95%CI: 0.47–0.92) and volume (n = 8, r = 0.58, p = 0.0186, 95%CI: 0.15–0.85) strongly correlate with pulmonary deposition of inhaled drugs.Item Local Effects of Two Intravenous Formulations of Pulmonary Vasodilators on Airway Epithelium(AARC, 2020-10) Kuch, Bradley A.; Linssen, Rosalie; Yoshikawa, Hiroki; Smallwood, Craig D.; Davis, Michael D.; Pediatrics, School of MedicineBACKGROUND: Intravenous formulations of epoprostenol are frequently delivered via nebulizer to treat pulmonary hypertension in acutely ill patients. Although their efficacy as pulmonary vasodilators has been shown to be comparable to inhaled nitric oxide, the local effects of these formulations within the airways have not been determined. We hypothesized that the alkaline diluents of these compounds would lead to increased airway epithelial cell death and ciliary cessation. METHODS: Human bronchial epithelial cells were exposed to epoprostenol in glycine and arginine diluents or control fluid. Ciliary beat frequency, lactate dehydrogenase, and total RNA levels were measured before and after exposure. Results were compared between exposure and control groups. RESULTS: Ciliary beat frequency ceased immediately after exposure to epoprostenol with both diluents. Lactate dehydrogenase levels increased by 200% after exposure to epoprostenol and glycine diluent (P = .002). Total RNA levels were undetectable after exposure to epoprostenol and arginine, indicating complete cell death and lysis (P = .015). Ciliary beat frequency ceased after 30 s of exposure to epoprostenol and glycine (P = .008). There was no difference between cells exposed to epoprostenol and those exposed only to diluent. CONCLUSIONS: Exposure to intravenous formulations of epoprostenol in glycine and arginine caused increased cell death and ciliary cessation in bronchial epithelial cells. These findings suggest that undesired local effects may occur when these compounds are delivered as inhaled aerosols to patients.Item Methods to Detect Volatile Organic Compounds for Breath Biopsy Using Solid-Phase Microextraction and Gas Chromatography–Mass Spectrometry(MDPI, 2023-06-03) Schulz, Eray; Woollam, Mark; Grocki, Paul; Davis, Michael D.; Agarwal, Mangilal; Chemistry and Chemical Biology, School of ScienceVolatile organic compounds (VOCs) are byproducts from metabolic pathways that can be detected in exhaled breath and have been reported as biomarkers for different diseases. The gold standard for analysis is gas chromatography–mass spectrometry (GC–MS), which can be coupled with various sampling methods. The current study aims to develop and compare different methods for sampling and preconcentrating VOCs using solid-phase microextraction (SPME). An in-house sampling method, direct-breath SPME (DB–SPME), was developed to directly extract VOCs from breath using a SPME fiber. The method was optimized by exploring different SPME types, the overall exhalation volume, and breath fractionation. DB–SPME was quantitatively compared to two alternative methods involving the collection of breath in a Tedlar bag. In one method, VOCs were directly extracted from the Tedlar bag (Tedlar–SPME) and in the other, the VOCs were cryothermally transferred from the Tedlar bag to a headspace vial (cryotransfer). The methods were verified and quantitatively compared using breath samples (n = 15 for each method respectively) analyzed by GC–MS quadrupole time-of-flight (QTOF) for compounds including but not limited to acetone, isoprene, toluene, limonene, and pinene. The cryotransfer method was the most sensitive, demonstrating the strongest signal for the majority of the VOCs detected in the exhaled breath samples. However, VOCs with low molecular weights, including acetone and isoprene, were detected with the highest sensitivity using the Tedlar–SPME. On the other hand, the DB–SPME was less sensitive, although it was rapid and had the lowest background GC–MS signal. Overall, the three breath-sampling methods can detect a wide variety of VOCs in breath. The cryotransfer method may be optimal when collecting a large number of samples using Tedlar bags, as it allows the long-term storage of VOCs at low temperatures (−80 °C), while Tedlar–SPME may be more effective when targeting relatively small VOCs. The DB-SPME method may be the most efficient when more immediate analyses and results are required.