Publications by authors named "Robert A Campbell"

Platelet shape and volume changes are early mechanical events contributing to platelet activation and thrombosis. Here, we identify single-nucleotide polymorphisms in Leucine-Rich Repeat Containing 8 (LRRC8) protein subunits that form the Volume-Regulated Anion Channel (VRAC) which are independently associated with altered mean platelet volume. LRRC8A is required for functional VRAC in megakaryocytes (MKs) and regulates platelet volume, adhesion, and agonist-stimulated activation, aggregation, ATP secretion and calcium mobilization.

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Background: Polyphenols have been shown to decrease oxidative stress and modulate glycemic response. Nevertheless, their effect on platelet bioenergetics and clot structure in diabetes and hyperglycemia is unknown.

Objectives: To investigate the effect of polyphenols on human platelet bioenergetics and its subsequent effect on clot structure in normoglycemia vs acute hyperglycemia .

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Genome-wide platelet transcriptomics is increasingly used to uncover new aspects of platelet biology and as a diagnostic and prognostic tool. Nevertheless, platelet isolation methods for transcriptomic studies are not standardized, introducing challenges for cross-study comparisons, data integration, and replication. In this prospective multicenter study, called "Standardizing Platelet Transcriptomics for Discovery, Diagnostics, and Therapeutics in the Thrombosis and Hemostasis Community (STRIDE)" by the International Society on Thrombosis and Haemostasis Scientific and Standardization Committees, we assessed how 3 of the most commonly used platelet isolation protocols influence metrics from next-generation bulk RNA sequencing and functional assays.

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Background: Aging is an independent risk factor for the development of cardiovascular, thrombotic, and other chronic diseases. However, mechanisms of platelet hyperactivation in aging remain poorly understood.

Objectives: Here, we examine whether and how aging alters intracellular signaling in platelets to support platelet hyperactivity and thrombosis.

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We created the c.1286C>G stop-gain mutation found in a family with primary ovarian insufficiency (POI) at age 30 years. The C57/Bl6 transgenic mouse model contained a floxed exon 10-19 cassette with a conditional knock-in cassette containing the c.

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Objectives: Racial and ethnic differences in drug testing have been described among adults and newborns. Less is known regarding testing patterns among children and adolescents. We sought to describe the association between race and ethnicity and drug testing at US children's hospitals.

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A State of the Art lecture titled "Immunothrombosis in Neurovascular Diseases" was presented at the International Society on Thrombosis and Haemostasis Congress in 2023. Despite significant clinical advancements in stroke therapy, stroke remains a prominent contributor to both mortality and disability worldwide. Brain injury resulting from an ischemic stroke is a dynamic process that unfolds over time.

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Background: Single-nucleotide polymorphisms linked with the rs1474868 T allele ( [mitofusin-2] T/T) in the human mitochondrial fusion protein gene are associated with reduced platelet RNA expression and platelet counts. This study investigates the impact of MFN2 on megakaryocyte and platelet biology.

Methods: Mice with megakaryocyte/platelet deletion of ( [ conditional knockout]) were generated using Pf4-Cre crossed with floxed mice.

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Transglutaminase factor XIII (FXIII) is essential for hemostasis, wound healing, and pregnancy maintenance. Plasma FXIII is composed of A and B subunit dimers synthesized in cells of hematopoietic origin and hepatocytes, respectively. The subunits associate tightly in circulation as FXIII-A2B2.

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Through the ACE2, a main enzyme of the renin-angiotensin system (RAS), SARS-CoV-2 gains access into the cell, resulting in different complications which may extend beyond the RAS and impact the Arachidonic Acid (ArA) pathway. The contribution of the RAS through ArA pathways metabolites in the pathogenesis of COVID-19 is unknown. We investigated whether RAS components and ArA metabolites can be considered biomarkers of COVID-19.

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Protease-activated receptor 4 (PAR4) (gene F2RL3) harbors a functional dimorphism, rs773902 A/G (encoding Thr120/Ala120, respectively) and is associated with greater platelet aggregation. The A allele frequency is more common in Black individuals, and Black individuals have a higher incidence of ischemic stroke than White individuals. However, it is not known whether the A allele is responsible for worse stroke outcomes.

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Purpose Of Review: Platelet mitochondrial dysfunction is both caused by, as well as a source of oxidative stress. Oxidative stress is a key hallmark of metabolic disorders such as dyslipidemia and diabetes, which are known to have higher risks for thrombotic complications.

Recent Findings: Increasing evidence supports a critical role for platelet mitochondria beyond energy production and apoptosis.

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Background: Medicine procedure services (MPS) increasingly perform bedside procedures, including lumbar punctures (LPs). Success rates and factors associated with LP success performed by MPS have not been well described.

Objective: We identified patients undergoing LP by an MPS September 2015 to December 2020.

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Background: Circulating procoagulant extracellular vesicles (EVs) are increased in diseases, such as cancer, sepsis, and COVID-19. EV tissue factor (TF) activity is associated with disseminated intravascular coagulation in sepsis and venous thrombosis in patients with pancreatic cancer and COVID-19. EVs are commonly isolated by centrifugation at ∼20,000 g.

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Introduction: Neutrophil extracellular traps (NETs) clear pathogens but may contribute Q8 pathogenically to host inflammatory tissue damage during sepsis. Innovative therapeutic agents targeting NET formation and their potentially harmful collateral effects remain understudied.

Methods: We investigated a novel therapeutic agent, neonatal NET-Inhibitory Factor (nNIF), in a mouse model of experimental sepsis - cecal ligation and puncture (CLP).

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Non-acute subdural hematomas (NASHs) are a cause of significant morbidity and mortality, particularly with recurrences. Although recurrence is believed to involve a disordered neuroinflammatory cascade involving vascular endothelial growth factor (VEGF), this pathway has yet to be completely elucidated. Neutrophil extracellular traps (NETs) are key factors that promote inflammation/apoptosis and can be induced by VEGF.

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Platelets and megakaryocytes are critical players in immune responses. Recent reports suggest infection and inflammation alter the megakaryocyte and platelet transcriptome to induce altered platelet reactivity. We determined whether nonviral sepsis induces differential platelet gene expression and reactivity.

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Platelets play a key role in maintaining hemostasis. However, dysregulated platelet activation can lead to pathological thrombosis or bleeding. Once a platelet gets activated, it will either become an aggregatory platelet or eventually a procoagulant platelet with both types playing distinct roles in thrombosis and hemostasis.

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