Publications by authors named "Dawn Parsell"

Significance Statement: Metabolic acidosis is a common complication of CKD and is associated with more rapid decline of kidney function, but well-powered controlled randomized trials testing the effect of treating metabolic acidosis on slowing CKD progression have not been conducted. The VALOR-CKD study randomized 1480 individuals with CKD and metabolic acidosis, across 320 sites to placebo or veverimer (a novel hydrochloric acid binder). The findings did not demonstrate the efficacy of veverimer in slowing CKD progression, but the difference in serum bicarbonate between placebo and drug arms was only approximately 1 mEq/L.

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Introduction: Expression of human complement pathway regulatory proteins (hCPRP's) such as CD46 or CD55 has been associated with improved survival of pig organ xenografts in multiple different models. Here we evaluate the hypothesis that an increased human CD46 gene dose, through homozygosity or additional expression of a second hCPRP, is associated with increased protein expression and with improved protection from injury when GTKO lung xenografts are perfused with human blood.

Methods: Twenty three GTKO lungs heterozygous for human CD46 (GTKO.

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Background: Although there have been many studies on antibody responses to SARS-CoV-2 in breast milk, very few have looked at the fate of these in the infant, and whether they are delivered to immunologically relevant sites in infants.

Methods: Mother/infant pairs (mothers who breast milk fed and who were SARS-CoV-2 vaccinated before or after delivery) were recruited for this cross-sectional study. Mother blood, mother breast milk, infant blood, infant nasal specimen, and infant stool was tested for IgA and IgG antibodies against SARS-CoV-2 spike trimer.

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Background: Whether treating metabolic acidosis slows progression of chronic kidney disease (CKD) has not been established. Veverimer is a novel hydrochloric acid binder that removes acid from the gastrointestinal tract leading to an increase in serum bicarbonate; it is being developed to treat metabolic acidosis with the goal of slowing progression of CKD.

Methods: The VALOR-CKD trial is an international, randomized, multicenter, double-blind, placebo-controlled study designed to evaluate the effect of once-daily veverimer on kidney disease progression in patients with metabolic acidosis and CKD.

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Article Synopsis
  • The study investigates additional genetic modifications in pigs to improve liver xenotransplant models by reducing anti-pig antibodies and managing coagulation issues.
  • Results show that liver perfusion time significantly increased in genetically modified pigs, and the need for heparin was notably reduced, indicating improved function with these modifications.
  • The combination of genetic changes alongside pharmacologic treatments led to a decrease in platelet activation and coagulation activity, suggesting better outcomes for xenotransplants.
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Galactosyl transferase knock-out pig lungs fail rapidly in baboons. Based on previously identified lung xenograft injury mechanisms, additional expression of human complement and coagulation pathway regulatory proteins, anti-inflammatory enzymes and self-recognition receptors, and knock-down of the β4Gal xenoantigen were tested in various combinations. Transient life-supporting GalTKO.

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Veverimer is a polymer being developed as a potential treatment of metabolic acidosis in patients with chronic kidney disease. Veverimer selectively binds and removes hydrochloric acid from the gastrointestinal tract, resulting in an increase in serum bicarbonate. Veverimer is not systemically absorbed, so potential drug-drug interactions (DDIs) are limited to effects on the absorption of other oral drugs through binding to veverimer in the gastrointestinal tract or increases in gastric pH caused by veverimer binding to hydrochloric acid.

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Objectives: Cardiosphere-derived cell (CDC) transplantation has been shown to attenuate right ventricular (RV) dysfunction in patients with hypoplastic left heart syndrome. However, live cell transplantation requires complex handling protocols that may limit its use. Exosomes are protein and nucleic acid-containing nanovesicles secreted by many cell types, including stem cells, which have been shown to exert a cardioprotective effect comparable with whole cells following myocardial injury.

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Background: Metabolic acidosis, a complication of chronic kidney disease, causes protein catabolism and bone demineralisation and is associated with adverse kidney outcomes and mortality. Veverimer, a non-absorbed, counterion-free, polymeric drug candidate selectively binds and removes hydrochloric acid from the gastrointestinal lumen.

Methods: We did a multicentre, randomised, blinded, placebo-controlled, 40-week extension of a 12-week parent study at 29 sites (hospitals and specialty clinics) in seven countries (Bulgaria, Georgia, Hungary, Serbia, Slovenia, Ukraine, and the USA).

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Background: Patients with advanced chronic kidney disease lose the capacity to fully excrete endogenous acid, resulting in chronic metabolic acidosis that increases the risk of disease progression and causes muscle catabolism and bone resorption. Veverimer, a non-absorbed, counterion-free, polymeric drug, selectively binds and removes hydrochloric acid from the gastrointestinal lumen, unlike current oral sodium bicarbonate therapy for metabolic acidosis that only neutralises accumulated acid. We assessed the efficacy and safety of veverimer as a treatment for metabolic acidosis in patients with chronic kidney disease.

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Background: Elevated pulmonary vascular resistance (PVR), platelet adhesion, coagulation activation, and inflammation are prominent features of xenolung rejection. Here, we evaluate the role of thromboxane and histamine on PVR, and their contribution to other lung xenograft injury mechanisms.

Methods: GalTKO.

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Background: There are numerous studies in the cardiovascular literature that have employed transesophageal echocardiography (TEE) in swine models, but data regarding the use of basic TEE in swine models is limited. The primary aim of this study is to describe an echocardiographic method that can be used with relative ease to qualitatively assess cardiovascular function in a porcine hemorrhagic shock model using resuscitative endovascular balloon occlusion of the aorta (REBOA).

Methods: Multiplane basic TEE exams were performed in 15 during an experimental hemorrhage model using REBOA.

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Background: Vascularized composite allotransplantation is constrained by complications associated with standard immunosuppressive strategies. Vascularized thymus and bone marrow have been shown to promote prolonged graft survival in composite organ and soft-tissue vascularized composite allotransplantation models. We report development of a nonhuman primate vascularized thymosternal composite tissue transplant model as a platform to address donor-specific immune tolerance induction strategies.

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Article Synopsis
  • - The need for better immunosuppression and the shortage of human organs are significant challenges in organ transplantation, prompting research into xenotransplantation using pig organs, which currently face issues like rapid inflammation and organ failure when perfused with human blood.
  • - A study used microfluidic channels to assess how human leukocytes interact with porcine endothelial cells, testing two compounds (GMI-1271 and rPSGL1.Fc) that block selectins to reduce the adhesion of human neutrophils.
  • - Results showed that blocking E- and P-selectins dramatically decreased neutrophil rolling and adhesion in a dose-dependent manner, indicating that selectin blockade could help prevent endothelial injury in xenotransplants and improve organ
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Background And Objectives: Metabolic acidosis is common in patients with CKD and has significant adverse effects on kidney, muscle, and bone. We tested the efficacy and safety of TRC101, a novel, sodium-free, nonabsorbed hydrochloric acid binder, to increase serum bicarbonate in patients with CKD and metabolic acidosis.

Design, Setting, Participants, & Measurements: One hundred thirty-five patients were enrolled in this randomized, double-blind, placebo-controlled, multicenter, in-unit study (designated the TRCA-101 Study).

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Organ scaffold bioengineering is currently limited by the inability to effectively repopulate the scaffold with appropriately distributed functional cells. We examined the feasibility of a decellularized liver scaffold to support the growth and function of multilineage allogenic cells derived from either adult or neonatal liver cells. Cell slurries from neonatal and adult rat livers containing hepatocytes, cholangiocytes, and endothelial cells were introduced into decellularized adult rat liver scaffolds via the bile duct.

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Background: Wild-type pigs express several carbohydrate moieties on their cell surfaces that differ from those expressed by humans. This difference in profile leads to pig tissue cell recognition of human blood cells causing sequestration, in addition to antibody-mediated xenograft injury. One such carbohydrate is N-glycolylneuraminic acid (Neu5Gc), a sialic acid molecule synthesized in pigs but not in humans.

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Background: Lung xenografts remain susceptible to loss of vascular barrier function within hours in spite of significant incremental advances based on genetic engineering to remove the Gal 1,3-αGal antigen (GalTKO) and express human membrane cofactor protein (hCD46). Natural killer cells rapidly disappear from the blood during perfusion of GalTKO.hCD46 porcine lungs with human blood and presumably are sequestered within the lung vasculature.

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Recent years have seen a proliferation of methods leading to successful organ decellularization. In this experiment we examine the feasibility of a decellularized liver construct to support growth of functional multilineage cells. Bio-chamber systems were used to perfuse adult rat livers with 0.

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Mice expressing the human Cu(2+)/Zn(2+) superoxide dismutase 1 (hSOD1) gene mutation (hSOD1(G93A); G93A) were exposed to methylmercury (MeHg) at concentrations that did not cause overt motor dysfunction. We hypothesized that low concentrations of MeHg could hasten development of the amyotrophic lateral sclerosis (ALS)-like phenotype in G93A mice. MeHg (1 or 3 ppm/day in drinking water) concentration-dependently accelerated the onset of rotarod failure in G93A, but not wild-type, mice.

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