Importance: Despite guideline recommendations to use low-molecular-weight heparins (LMWHs) or direct oral anticoagulants in the treatment of most patients with acute pulmonary embolism (PE), US-based studies have found increasing use of unfractionated heparin (UFH) in hospitalized patients.
Objective: To identify barriers and facilitators of guideline-concordant anticoagulation in patients hospitalized with acute PE.
Design, Setting, And Participants: This qualitative study conducted semistructured interviews from February 1 to June 3, 2024, that were recorded, transcribed, and analyzed in an iterative process using reflexive thematic analysis.
Background: High-sensitivity troponin T (HS-TnT) may improve risk-stratification in hemodynamically stable acute pulmonary embolism (PE), but an optimal strategy for combining this biomarker with clinical risk-stratification tools has not been determined.
Study Hypothesis: We hypothesized that different HS-TnT cutoff values may be optimal for identifying (1) low-risk patients who may be eligible for outpatient management and (2) patients at increased risk of clinical deterioration who might benefit from advanced PE therapies.
Methods: Retrospective analysis of hemodynamically stable patients in the University of Michigan acute ED-PE registry with available HS-TnT values.
Currently available biotherapeutics for the treatment of osteoporosis lack explicit mechanisms for bone localization, potentially limiting efficacy and inducing off-target toxicities. While various strategies have been explored for targeting the bone surface, critical aspects remain poorly understood, including the optimal affinity ligand, the role of binding avidity and circulation time, and, most importantly, whether or not this strategy can enhance the functional activity of clinically relevant protein therapeutics. To investigate, we generated fluorescent proteins (eg, mCherry) with site-specifically attached small molecule (bisphosphonate) or peptide (deca-aspartate, D10) affinity ligands.
View Article and Find Full Text PDFThe inability of antibodies to penetrate the blood-brain barrier (BBB) is a key limitation to their use in diverse applications. One promising strategy is to deliver IgGs using a bispecific BBB shuttle, which involves fusing an IgG to a second affinity ligand that engages a cerebrovascular endothelial target and facilitates transport across the BBB. Nearly all prior efforts have focused on shuttles that target transferrin receptor (TfR-1) despite inherent delivery and safety challenges.
View Article and Find Full Text PDFAim: To evaluate coagulofibrinolytic abnormalities and the effects of ART-123 (recombinant human thrombomodulin alpha) in a porcine model of cardiac arrest and prolonged cardiopulmonary resuscitation (CA/CPR).
Methods: Fifteen pigs ( = 5 per group) underwent 8 minutes of no-flow CA followed by 50 minutes of mechanical CPR, while 2 pigs underwent sham arrest. CA/CPR animals were randomized to receive saline or 1 mg/kg ART-123 pre-arrest (5 minutes prior to ventricular fibrillation) or post-arrest (2 minutes after initiation of CPR).
-loaded white blood cells (WBC) can transfer cargo to pathological foci in the central nervous system (CNS). Here we tested affinity ligand driven loading of WBC in order to bypass the need for WBC manipulation. We used a mouse model of acute brain inflammation caused by local injection of tumor necrosis factor alpha (TNF-α).
View Article and Find Full Text PDFAcute pulmonary embolism (PE) is a frequently diagnosed condition. Prediction of in-hospital deterioration is challenging with current risk models. The Calgary Acute Pulmonary Embolism (CAPE) score was recently derived to predict in-hospital adverse PE outcomes but has not yet been externally validated.
View Article and Find Full Text PDFImportance: Most patients presenting to US emergency departments (EDs) with acute pulmonary embolism (PE) are hospitalized, despite evidence from multiple society-based guidelines recommending consideration of outpatient treatment for those with low risk stratification scores. One barrier to outpatient treatment may be clinician concern regarding findings on PE-protocol computed tomography (CTPE), which are perceived as high risk but not incorporated into commonly used risk stratification tools.
Objective: To evaluate the association of concerning CTPE findings with outcomes and treatment of patients in the ED with acute, low-risk PE.
The inability of antibodies and other biologics to penetrate the blood-brain barrier (BBB) is a key limitation to their use in diagnostic, imaging, and therapeutic applications. One promising strategy is to deliver IgGs using a bispecific BBB shuttle, which involves fusing an IgG with a second affinity ligand that engages a cerebrovascular endothelial target and facilitates transport across the BBB. Nearly all prior efforts have focused on the transferrin receptor (TfR-1) as the prototypical endothelial target despite inherent delivery and safety challenges.
View Article and Find Full Text PDFBackground: Pulmonary Embolism Response Teams (PERT) were employed at multiple institutions to bridge the gap between varied treatment options for acute PE and unclear evidence for optimal management. There is limited data regarding the impact of PERT on the use of advanced therapies and clinical outcomes.
Methods: We performed a retrospective single-center cohort study comparing patients that presented to the ED with an acute PE before and after the creation of PERT in June 2017 at our institution.
Background and objective Although hospitalization is required for only a minority of those infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the high rates of morbidity and mortality among these patients have led researchers to focus on the predictors of admission and adverse outcomes in the inpatient population. However, there is scarce data on the clinical trajectory of individuals symptomatic enough to present for emergency care, but not sick enough to be admitted. In light of this, we aimed to examine the symptomatology, emergency department (ED) revisits, and hospitalization of coronavirus disease 2019 (COVID-19) outpatients after discharge from the ED.
View Article and Find Full Text PDFAcidic pH is critical to the function of the gastrointestinal system, bone-resorbing osteoclasts, and the endolysosomal compartment of nearly every cell in the body. Non-invasive, real-time fluorescence imaging of acidic microenvironments represents a powerful tool for understanding normal cellular biology, defining mechanisms of disease, and monitoring for therapeutic response. While commercially available pH-sensitive fluorescent probes exist, several limitations hinder their widespread use and potential for biologic application.
View Article and Find Full Text PDFImmune thrombocytopenia (ITP) is an acquired bleeding disorder characterized by immunoglobulin G (IgG)-mediated platelet destruction. Current therapies primarily focus on reducing antiplatelet antibodies using immunosuppression or increasing platelet production with thrombopoietin mimetics. However, there are no universally safe and effective treatments for patients presenting with severe life-threatening bleeding.
View Article and Find Full Text PDFEngineering drug delivery systems for prolonged pharmacokinetics (PK) has been an ongoing pursuit for nearly 50 years. The gold standard for PK enhancement is the coating of nanoparticles with polymers, namely polyethylene glycol (PEGylation), which has been applied in several clinically used products. In the present work, we utilize the longest circulating and most abundant component of blood─the erythrocyte─to improve the PK behavior of liposomes.
View Article and Find Full Text PDFFront Bioeng Biotechnol
March 2022
The bone is a mechanosensitive organ that is also a common metastatic site for prostate cancer. However, the mechanism by which the tumor interacts with the bone microenvironment to further promote disease progression remains to be fully understood. This is largely due to a lack of physiological yet user-friendly models that limit our ability to perform in-depth mechanistic studies.
View Article and Find Full Text PDFThis study shows that the supramolecular arrangement of proteins in nanoparticle structures predicts nanoparticle accumulation in neutrophils in acute lung inflammation (ALI). We observed homing to inflamed lungs for a variety of nanoparticles with agglutinated protein (NAPs), defined by arrangement of protein in or on the nanoparticles via hydrophobic interactions, crosslinking and electrostatic interactions. Nanoparticles with symmetric protein arrangement (for example, viral capsids) had no selectivity for inflamed lungs.
View Article and Find Full Text PDFThe identification of antibody variable regions in the heavy (VH) and light (VL) chains from hybridomas is necessary for the production of recombinant, sequence-defined monoclonal antibodies (mAbs) and antibody derivatives. This process has received renewed attention in light of recent reports of hybridomas having unintended specificities due to the production of non-antigen specific heavy and/or light chains for the intended antigen. Here we report a surprising finding and potential pitfall in variable domain sequencing of an anti-human CD63 hybridoma.
View Article and Find Full Text PDFBackground: Early administration of convalescent plasma obtained from blood donors who have recovered from coronavirus disease 2019 (Covid-19) may prevent disease progression in acutely ill, high-risk patients with Covid-19.
Methods: In this randomized, multicenter, single-blind trial, we assigned patients who were being treated in an emergency department for Covid-19 symptoms to receive either one unit of convalescent plasma with a high titer of antibodies against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) or placebo. All the patients were either 50 years of age or older or had one or more risk factors for disease progression.
Single-chain protein affinity ligands are recombinant polypeptides that recreate the antigen-binding site of parental, monoclonal antibodies (mAbs) or present unique binding surfaces derived from display technologies, computational design, or other approaches. These diverse ligands have several advantages over full-length mAbs as agents for delivery of small molecule, protein, and nanoparticle cargoes to desired sites in the body. However, they present unique challenges for modification and bioconjugation.
View Article and Find Full Text PDFTargeted drug delivery to the endothelium has the potential to generate localized therapeutic effects at the blood-tissue interface. For some therapeutic cargoes, it is essential to maintain contact with the bloodstream to exert protective effects. The pharmacokinetics (PK) of endothelial surface-targeted affinity ligands and biotherapeutic cargo remain a largely unexplored area, despite obvious translational implications for this strategy.
View Article and Find Full Text PDFThe use of single-domain antibody fragments, or nanobodies, has gained popularity in recent years as an alternative to traditional monoclonal antibody-based approaches. Relatively little is known, however, about the utility of nanobodies as targeting agents for delivery of therapeutic cargoes, particularly to vascular epitopes or in the setting of acute inflammatory conditions. We used a nanobody (VCAMelid) directed against mouse vascular cell adhesion molecule 1 (VCAM-1) and techniques for site-specific radiolabeling and bioconjugation to measure targeting to sites of constitutive and inducible antigen expression and investigate the impact of various characteristics (affinity, valence, circulation time) on nanobody biodistribution and pharmacokinetics.
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