Publications by authors named "Richard J Massey"

Background: Obstructive sleep apnoea (OSA) can cause left atrial (LA) and left ventricular (LV) remodelling, which is linked to atrial fibrillation (AF). Whether continuous positive airway pressure (CPAP) can reverse LA and LV remodelling in patients with OSA and paroxysmal AF (PAF) has yet to be studied. We assessed the impact of CPAP treatment on LA and LV size and function in patients with OSA and PAF before and after catheter ablation.

View Article and Find Full Text PDF

Aims: The non-invasive myocardial work index (MWI) has been validated in patients without aortic stenosis (AS). A thorough assessment of methodological limitations is warranted before this index can be applied to patients with AS.

Methods And Results: We simultaneously measured left ventricular pressure (LVP) by using a micromanometer-tipped catheter and obtained echocardiograms in 20 patients with severe AS.

View Article and Find Full Text PDF

Purpose: Exercise intolerance is a common complication in survivors of allogeneic hematopoietic stem-cell transplantation (allo-HSCT). The aim of this study was to determine if cardiac function measured with echocardiography is associated with exercise capacity measured with cardio-pulmonary exercise tests in long-term survivors treated in their youth with allo-HSCT.

Methods: The study included 96 patients, of which 54.

View Article and Find Full Text PDF

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is an established treatment predominantly for malignancies. Chronic graft-versus-host disease (cGVHD) is the leading long-term complication after allo-HSCT, but knowledge on cGVHD and health-related quality of life (HRQOL) in long-term survivors of allo-HSCT performed in childhood, adolescence, and young adulthood (CAYA) is scarce. Therefore, we aimed to (1) assess prevalence and risk factors of active cGVHD using the 2014 National Institutes of Health-Consensus criteria, (2) investigate associations between cGVHD severity, patient-reported symptom burden, and HRQOL, and (3) compare HRQOL of survivors to population norms.

View Article and Find Full Text PDF

Objective: Dysregulation of the complement system has been described in patients with heart failure (HF). However, data on the alternative pathway are scarce and it is unknown if levels of factor B (FB) and the C3 convertase C3bBbP are elevated in these patients. We hypothesized that plasma levels of FB and C3bBbP would be associated with disease severity and survival in patients with HF.

View Article and Find Full Text PDF

Aims: Survivors of allogeneic haematopoietic stem-cell transplantation (allo-HSCT) are at higher risk of cardiovascular disease. We aimed to describe right ventricular (RV) systolic function and risk factors for RV dysfunction in long-term survivors of allo-HSCT performed in their youth.

Methods And Results: This cohort included 103 survivors (53% female), aged (mean±SD) 17.

View Article and Find Full Text PDF

Background: Allogeneic hematopoietic stem cell transplantation (allo-HSCT), a potentially curative therapy for malignant and nonmalignant diseases, is being increasingly used in younger patients. Although allo-HSCT survivors have an established increased risk of cardiovascular disease, there is limited knowledge of the long-term effects on cardiac function in survivors.

Objectives: The purpose of this study was to describe left ventricular (LV) systolic function in long-term allo-HSCT survivors treated in childhood, adolescence, or early adulthood.

View Article and Find Full Text PDF

Sleep apnea (SA) is highly prevalent in patients with atrial fibrillation (AF), and both conditions are associated with adverse cardiovascular outcomes. To determine the effect of continuous positive airway pressure (CPAP) on AF burden. This open-label, parallel-group, randomized controlled trial included patients with paroxysmal AF and moderate to severe SA (apnea-hypopnea index ⩾15).

View Article and Find Full Text PDF

Purpose: Survivors of allogeneic hematopoietic stem cell transplantation (allo-HSCT) are at risk for cardiopulmonary adverse events. Data on long-term effects on cardiorespiratory fitness are limited. To address the gap in knowledge, we aimed to determine peak oxygen uptake (V̇Opeak) and identify associations between cardiorespiratory fitness and clinical characteristics, self-reported physical activity, cardiac, and pulmonary function.

View Article and Find Full Text PDF

At a fraction of the total cost of an equivalent orbital mission, scientific balloon-borne platforms, operating above 99.7% of the Earth's atmosphere, offer attractive, competitive, and effective observational capabilities-namely, space-like seeing, transmission, and backgrounds-which are well suited for modern astronomy and cosmology. The Super-pressure Balloon-borne Imaging Telescope (SUPERBIT) is a diffraction-limited, wide-field, 0.

View Article and Find Full Text PDF

Quantum mechanics-based design of useful catalytic antibodies (catabodies) failed because of the uncertain structure of the dynamic catalyst-substrate complex. The Catabody Platform emerged from discovery of beneficial germline gene catabodies that hydrolyzed self-proteins by transient covalent pairing of the strong catabody nucleophile with a weak target protein electrophile. Catabodies have evolved by Darwinian natural selection for protection against misfolded self-proteins that threatened survival by causing amyloid disease.

View Article and Find Full Text PDF

With the advancement of three-dimensional (3-D) real-time echocardiography in recent years, automatic creation of patient specific geometric models is becoming feasible and important in clinical decision making. However, the vast majority of echocardiographic segmentation methods presented in the literature focus on the left ventricle (LV) endocardial border, leaving segmentation of the right ventricle (RV) a largely unexplored problem, despite the increasing recognition of the RV's role in cardiovascular disease. We present a method for coupled segmentation of the endo- and epicardial borders of both the LV and RV in 3-D ultrasound images.

View Article and Find Full Text PDF

Background: In recipients with type 1 diabetes, we aimed to determine whether long-term normoglycemia achieved by successful simultaneous pancreas and kidney (SPK) transplantation could beneficially affect progression of coronary artery disease (CAD) when compared with transplantation of a kidney-alone from a living donor (LDK).

Methods: In 42 kidney transplant recipients with functioning grafts who had received either SPK (n = 25) or LDK (n = 17), we studied angiographic progression of CAD between baseline (pretransplant) and follow-up at 7 years or older. In addition, computed tomography scans for measures of coronary artery calcification and echocardiographic assessment of left ventricular systolic function were addressed at follow-up.

View Article and Find Full Text PDF

As the right ventricle's (RV) role in cardiovascular diseases is being more widely recognized, interest in RV imaging, function and quantification is growing. However, there are currently few RV quantification methods for 3D echocardiography presented in the literature or commercially available. In this paper we propose an automated RV segmentation method for 3D echocardiographic images.

View Article and Find Full Text PDF

Classical immunization methods do not generate catalytic antibodies (catabodies), but recent findings suggest that the innate antibody repertoire is a rich catabody source. We describe the specificity and amyloid β (Aβ)-clearing effect of a catabody construct engineered from innate immunity principles. The catabody recognized the Aβ C terminus noncovalently and hydrolyzed Aβ rapidly, with no reactivity to the Aβ precursor protein, transthyretin amyloid aggregates, or irrelevant proteins containing the catabody-sensitive Aβ dipeptide unit.

View Article and Find Full Text PDF

Objective: HIV is vulnerable to antibodies that recognize a linear CD4 binding site epitope of gp120 (C), but inducing C-directed antibody synthesis by traditional vaccine principles is difficult. We wished to understand the basis for deficient C-directed antibody synthesis and validate correction of the deficiency by an electrophilic gp120 analog (E-gp120) immunogen that binds B-cell receptors covalently.

Methods: Serum antibody responses to a C peptide and full-length gp120 epitopes induced by HIV infection in humans and immunization of mice with gp120 or E-gp120 were monitored.

View Article and Find Full Text PDF

Peptide bond-hydrolyzing catalytic antibodies (catabodies) could degrade toxic proteins, but acquired immunity principles have not provided evidence for beneficial catabodies. Transthyretin (TTR) forms misfolded β-sheet aggregates responsible for age-associated amyloidosis. We describe nucleophilic catabodies from healthy humans without amyloidosis that degraded misfolded TTR (misTTR) without reactivity to the physiological tetrameric TTR (phyTTR).

View Article and Find Full Text PDF

The immunodominant epitopes expressed by the HIV-1 envelope protein gp120 are hypermutable, defeating attempts to develop an effective HIV vaccine. Targeting the structurally conserved gp120 determinant that binds host CD4 receptors (CD4BD) and initiates infection is a more promising route to vaccination, but this has proved difficult because of the conformational flexibility of gp120 and immune evasion mechanisms used by the virus. Mimicking the outer CD4BD conformational epitopes is difficult because of their discontinuous nature.

View Article and Find Full Text PDF

Failure to induce synthesis of neutralizing Abs to the CD4 binding determinant (CD4BD) of gp120, a central objective in HIV vaccine research, has been alternately ascribed to insufficient immunogen binding to Abs in their germline V region configuration expressed as BCRs, insufficient adaptive mutations in Ab V regions, and conformational instability of gp120. We employed peptide analogs of gp120 residues 421-433 within the CD4BD (CD4BD(core)) to identify Abs produced without prior exposure to HIV (constitutive Abs). The CD4BD(core) peptide was recognized by single-chain Fv fragments from noninfected humans with lupus that neutralized genetically diverse strains belonging to various HIV subtypes.

View Article and Find Full Text PDF

Immunoglobulins (antibodies) frequently express constitutive functions. Two such functions are nucleophilic catalysis and the reversible binding to B-cell superantigens. Constitutive or "naturally-occurring" antibodies are produced spontaneously from germline genetic information.

View Article and Find Full Text PDF