89 research outputs found

    Relief of branch pulmonary artery stenosis reduces pulmonary valve insufficiency in a swine model

    Get PDF
    ObjectiveWe sought to determine the impact of relieving branch pulmonary artery stenosis on pulmonary valve insufficiency and right ventricular function. Long-standing pulmonary insufficiency causes progressive right ventricular dilatation, leading to decreased right ventricular function. Adults with pulmonary insufficiency are at risk of decreased exercise tolerance, arrhythmias, and sudden cardiac death. Branch pulmonary artery stenosis frequently occurs in these patients, and the presence of branch stenosis may exacerbate valve insufficiency.MethodsNeonatal piglets (n = 7) underwent surgery to create pulmonary insufficiency and left pulmonary artery stenosis. At 3 months of age, the animals underwent baseline cardiac magnetic resonance imaging followed by stenting of the left pulmonary artery. A repeat magnetic resonance imaging scan was performed 1 week after intervention. Magnetic resonance imaging evaluation included (1) velocity mapping to assess the forward and reverse flow at the main, left and right pulmonary arteries, and aorta; and (2) volumetric assessment of the right ventricle.ResultsLeft pulmonary artery flow increased from 14.5% to 36.3% of total net flow after stenting (P < .01). Pulmonary regurgitation decreased from 38.7% to 27.4% (P < .02). Right ventricular ejection fraction improved from a median of 53.5% to 58.2% after stenting (P < .01). Cardiac index improved from a median of 2.7 to 3.5 L/min/m2 (P = .01).ConclusionRelief of branch pulmonary artery stenosis reduces insufficiency and improves right ventricular systolic function in this animal model. This supports the practice of aggressive intervention in patients with branch pulmonary artery stenosis and pulmonary insufficiency

    Percutaneous Transvenous Melody Valve-in-Ring Procedure for Mitral Valve Replacement

    Get PDF
    ObjectivesThe purpose of this study was to demonstrate the feasibility of percutaneous transvenous mitral valve-in-ring (VIR) implantation using the Melody valve in an ovine model.BackgroundThe recurrence of mitral regurgitation following surgical mitral valve (MV) repair in both adult and pediatric patients remains a significant clinical problem. Mitral annuloplasty rings are commonly used in MV repair procedures and may serve as secure landing zones for percutaneous valves.MethodsFive sheep underwent surgical MV annuloplasty (24 mm, n = 2; 26 mm, n = 2; 28 mm, n = 1). Animals underwent cardiac catheterization with VIR implantation via a transfemoral venous, transatrial septal approach 1 week following surgery. Hemodynamic, angiographic, and echocardiographic data were recorded before and after VIR.ResultsVIR was technically successful and required <1 h of procedure time in all animals. Fluoroscopy demonstrated securely positioned Melody valves within the annuloplasty ring in all animals. Angiography revealed no significant MV regurgitation in 4 and moderate central MV regurgitation in the animal with the 28-mm annuloplasty. All animals demonstrated vigorous left ventricular function, no outflow tract obstruction, and no aortic valve insufficiency.ConclusionsThis study demonstrated the feasibility of a purely percutaneous approach to MV replacement in patients with preexisting annuloplasty rings. This novel approach may be of particular benefit to patients with failed repair of ischemic mitral regurgitation and in pediatric patients with complex structural heart disease

    Quantum Cognitive Modeling: New Applications and Systems Research Directions

    Full text link
    Expanding the benefits of quantum computing to new domains remains a challenging task. Quantum applications are concentrated in only a few domains, and driven by these few, the quantum stack is limited in supporting the development or execution demands of new applications. In this work, we address this problem by identifying both a new application domain, and new directions to shape the quantum stack. We introduce computational cognitive models as a new class of quantum applications. Such models have been crucial in understanding and replicating human intelligence, and our work connects them with quantum computing for the first time. Next, we analyze these applications to make the case for redesigning the quantum stack for programmability and better performance. Among the research opportunities we uncover, we study two simple ideas of quantum cloud scheduling using data from gate-based and annealing-based quantum computers. On the respective systems, these ideas can enable parallel execution, and improve throughput. Our work is a contribution towards realizing versatile quantum systems that can broaden the impact of quantum computing on science and society

    Clinical audit of foot problems in patients with rheumatoid arthritis treated at Counties Manukau District Health Board, Auckland, New Zealand

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>At diagnosis, 16% of rheumatoid arthritis (RA) patients may have foot joint involvement, increasing to 90% as disease duration increases. This can lead to joint instability, difficulties in walking and limitation in functional ability that restricts activities of daily living. The podiatrist plays an important role in the multidisciplinary team approach to the management of foot problems. The aim of this study was to undertake a clinical audit of foot problems in patients with RA treated at Counties Manukau District Health Board.</p> <p>Methods</p> <p>Patients with RA were identified through rheumatological clinics run within CMDHB. 100 patients were eligible for inclusion. Specific foot outcome tools were used to evaluate pain, disability and function. Observation on foot lesions were noted and previous history of foot assessment, footwear/insoles and foot surgery were evaluated.</p> <p>Results</p> <p>The median age of the cohort was 60 (IQR: 51–64) years old with median disease duration of 15 (IQR: 7.3–25) years. Over 85% presented with foot lesions that included corns and callus over the forefoot region and lesser toe deformities. Moderate to high disability was noted. High levels of forefoot structural damage were observed. 76% had not seen a podiatrist and 77% reported no previous formal foot assessment. 40% had been seen at the orthotic centre for specialised footwear and insoles. 27% of RA patients reported previous foot surgery. A large proportion of patients wore inappropriate footwear.</p> <p>Conclusion</p> <p>This clinical audit suggests that the majority of RA patients suffer from foot problems. Future recommendations include the provision of a podiatrist within the current CMDHB multidisciplinary rheumatology team to ensure better services for RA patients with foot problems.</p

    Identification of Novel Proteins in Neospora caninum Using an Organelle Purification and Monoclonal Antibody Approach

    Get PDF
    Neospora caninum is an important veterinary pathogen that causes abortion in cattle and neuromuscular disease in dogs. Neospora has also generated substantial interest because it is an extremely close relative of the human pathogen Toxoplasma gondii, yet does not appear to infect humans. While for Toxoplasma there are a wide array of molecular tools and reagents available for experimental investigation, relatively few reagents exist for Neospora. To investigate the unique biological features of this parasite and exploit the recent sequencing of its genome, we have used an organelle isolation and monoclonal antibody approach to identify novel organellar proteins and develop a wide array of probes for subcellular localization. We raised a panel of forty-six monoclonal antibodies that detect proteins from the rhoptries, micronemes, dense granules, inner membrane complex, apicoplast, mitochondrion and parasite surface. A subset of the proteins was identified by immunoprecipitation and mass spectrometry and reveal that we have identified and localized many of the key proteins involved in invasion and host interaction in Neospora. In addition, we identified novel secretory proteins not previously studied in any apicomplexan parasite. Thus, this organellar monoclonal antibody approach not only greatly enhances the tools available for Neospora cell biology, but also identifies novel components of the unique biological characteristics of this important veterinary pathogen

    Copy Number Variants Are Ovarian Cancer Risk Alleles at Known and Novel Risk Loci

    Get PDF

    Mortality and pulmonary complications in patients undergoing surgery with perioperative SARS-CoV-2 infection: an international cohort study

    Get PDF
    Background: The impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on postoperative recovery needs to be understood to inform clinical decision making during and after the COVID-19 pandemic. This study reports 30-day mortality and pulmonary complication rates in patients with perioperative SARS-CoV-2 infection. Methods: This international, multicentre, cohort study at 235 hospitals in 24 countries included all patients undergoing surgery who had SARS-CoV-2 infection confirmed within 7 days before or 30 days after surgery. The primary outcome measure was 30-day postoperative mortality and was assessed in all enrolled patients. The main secondary outcome measure was pulmonary complications, defined as pneumonia, acute respiratory distress syndrome, or unexpected postoperative ventilation. Findings: This analysis includes 1128 patients who had surgery between Jan 1 and March 31, 2020, of whom 835 (74·0%) had emergency surgery and 280 (24·8%) had elective surgery. SARS-CoV-2 infection was confirmed preoperatively in 294 (26·1%) patients. 30-day mortality was 23·8% (268 of 1128). Pulmonary complications occurred in 577 (51·2%) of 1128 patients; 30-day mortality in these patients was 38·0% (219 of 577), accounting for 81·7% (219 of 268) of all deaths. In adjusted analyses, 30-day mortality was associated with male sex (odds ratio 1·75 [95% CI 1·28–2·40], p\textless0·0001), age 70 years or older versus younger than 70 years (2·30 [1·65–3·22], p\textless0·0001), American Society of Anesthesiologists grades 3–5 versus grades 1–2 (2·35 [1·57–3·53], p\textless0·0001), malignant versus benign or obstetric diagnosis (1·55 [1·01–2·39], p=0·046), emergency versus elective surgery (1·67 [1·06–2·63], p=0·026), and major versus minor surgery (1·52 [1·01–2·31], p=0·047). Interpretation: Postoperative pulmonary complications occur in half of patients with perioperative SARS-CoV-2 infection and are associated with high mortality. Thresholds for surgery during the COVID-19 pandemic should be higher than during normal practice, particularly in men aged 70 years and older. Consideration should be given for postponing non-urgent procedures and promoting non-operative treatment to delay or avoid the need for surgery. Funding: National Institute for Health Research (NIHR), Association of Coloproctology of Great Britain and Ireland, Bowel and Cancer Research, Bowel Disease Research Foundation, Association of Upper Gastrointestinal Surgeons, British Association of Surgical Oncology, British Gynaecological Cancer Society, European Society of Coloproctology, NIHR Academy, Sarcoma UK, Vascular Society for Great Britain and Ireland, and Yorkshire Cancer Research
    corecore