Hemostatic complications associated with ventricular assist devices.

Hemostatic complications are common in patients with ventricular assist devices. The pathophysiologic mechanisms that lead to dysregulated hemostasis involve complex interactions between device surface, sheer stress, and blood flow. These factors lead to various manifestations that require a thorough understanding of the interplay among platelets, coagulation factors, and red cells. In this article, we review the pathophysiology of hematologic complications (bleeding, acquired von Willebrand disease, heparin-induced thrombocytopenia, hemolysis, stroke and pump thrombosis), the clinical manifestations, and the management of each. We summarize the evidence available for management of these entities and provide a pragmatic clinical review

Heart Failure Symptom Biology in Response to Ventricular Assist Device Implantation.

BACKGROUND: We have a limited understanding of the biological underpinnings of symptoms in heart failure (HF), particularly in response to left ventricular assist device (LVAD) implantation. OBJECTIVE: The aim of this study was to quantify the degree to which symptoms and biomarkers change in parallel from before implantation through the first 6 months after LVAD implantation in advanced HF. METHODS: This was a prospective cohort study of 101 patients receiving an LVAD for the management of advanced HF. Data on symptoms (dyspnea, early and subtle symptoms [HF Somatic Perception Scale], pain severity [Brief Pain Inventory], wake disturbance [Epworth Sleepiness Scale], depression [Patient Health Questionnaire], and anxiety [Brief Symptom Inventory]) and peripheral biomarkers of myocardial stretch, systemic inflammation, and hypervolumetric mechanical stress were measured before implantation with a commercially available LVAD and again at 30, 90, and 180 days after LVAD implantation. Latent growth curve and parallel process modeling were used to describe changes in symptoms and biomarkers and the degree to which they change in parallel in response to LVAD implantation. RESULTS: In response to LVAD implantation, changes in myocardial stretch were closely associated with changes in early and subtle physical symptoms as well as depression, and changes in hypervolumetric stress were closely associated with changes in pain severity and wake disturbances. Changes in systemic inflammation were not closely associated with changes in physical or affective symptoms in response to LVAD implantation. CONCLUSIONS: These findings provide new insights into the many ways in which symptoms and biomarkers provide concordant or discordant information about LVAD response

Environmental and societal factors affect food choice and physical activity: Rationale, influences, and leverage points

Dietary and physical activity behaviors that affect health are influenced by a wide variety of forces; changes in these behaviors require interventions and commitment to action at multiple levels.l.2 Education-based obesity-prevention strategies (e.g., mass-media promotion of healthy foods and promotion of healthy physical activity habits through schools) are viewed as the most useful and the most feasible to im~lementIm.~p licit in these strategies is the focus on the individual? Education-based strategies have met with limited long-term success in changing behavior: however, perhaps owing to a general lack of supporting environmental modifications. There is increasing recognition of the importance of the environment in shaping behavior, yet strategies that focus on changing environmental factors are much less familiar, and may therefore require partnerships with relevant sectors outside traditional health domains. As described in greater detail by Economos et al.: partnerships among researchers, educators, government, and industry have demonstrated success in smoking reduction at the population level. Interventions such as taxation and advertisement regulations have been instrumental in promoting smoking cessation in the United States and are used by agriculture and agribusiness interests to promote specific food consumption patterns. Similar models of collaborations or interventions may be successful in changing food intake and physical activity, and may potentially result in such desirable outcomes as prevention and reduction of obesity.6 It is important to appreciate the interaction among multiple environmental factors and that complex behavior changes are dependent on different influences at different levels. In Working Group 11, we took on the task of identifying broader contextual, environmental, societal, and policy variables that may improve our understanding of people's eating and physical activity behaviors and may lead to new directions for influencing shifts in behavior. Ecologic models of behavior, and most health promotion models, specify that health behaviors be influenced by biologic, demographic, psychological, sociaYcultura1, environmental, and policy variables. However, the research base that identifies specific important environmental and policy variables is very limited.'.""' Nevertheless, there are several reasons that support the need to identify environmental and policy influences on physical activity and eating behaviors

Heteroepitaxial growth of ferromagnetic MnSb(0001) films on Ge/Si(111) virtual substrates

Molecular beam epitaxial growth of ferromagnetic MnSb(0001) has been achieved on high quality, fully relaxed Ge(111)/Si(111) virtual substrates grown by reduced pressure chemical vapor deposition. The epilayers were characterized using reflection high energy electron diffraction, synchrotron hard X-ray diffraction, X-ray photoemission spectroscopy, and magnetometry. The surface reconstructions, magnetic properties, crystalline quality, and strain relaxation behavior of the MnSb films are similar to those of MnSb grown on GaAs(111). In contrast to GaAs substrates, segregation of substrate atoms through the MnSb film does not occur, and alternative polymorphs of MnSb are absent

SARS-CoV-2 booster vaccination rescues attenuated IgG1 memory B cell response in primary antibody deficiency patients

BACKGROUND: Although SARS-CoV-2 vaccines have proven effective in eliciting a protective immune response in healthy individuals, their ability to induce a durable immune response in immunocompromised individuals remains poorly understood. Primary antibody deficiency (PAD) syndromes are among the most common primary immunodeficiency disorders in adults and are characterized by hypogammaglobulinemia and impaired ability to mount robust antibody responses following infection or vaccination. METHODS: Here, we present an analysis of both the B and T cell response in a prospective cohort of 30 individuals with PAD up to 150 days following initial COVID-19 vaccination and 150 days post mRNA booster vaccination. RESULTS: After the primary vaccination series, many of the individuals with PAD syndromes mounted SARS-CoV-2 specific memory B and CD4 CONCLUSION: Together, these data indicate that SARS-CoV-2 vaccines elicit memory B and T cells in most PAD patients and highlights the importance of booster vaccination in immunodeficient individuals

Measurement of the production of a W boson in association with a charm quark in pp collisions at √s = 7 TeV with the ATLAS detector

The production of a W boson in association with a single charm quark is studied using 4.6 fb−1 of pp collision data at s√ = 7 TeV collected with the ATLAS detector at the Large Hadron Collider. In events in which a W boson decays to an electron or muon, the charm quark is tagged either by its semileptonic decay to a muon or by the presence of a charmed meson. The integrated and differential cross sections as a function of the pseudorapidity of the lepton from the W-boson decay are measured. Results are compared to the predictions of next-to-leading-order QCD calculations obtained from various parton distribution function parameterisations. The ratio of the strange-to-down sea-quark distributions is determined to be 0.96+0.26−0.30 at Q 2 = 1.9 GeV2, which supports the hypothesis of an SU(3)-symmetric composition of the light-quark sea. Additionally, the cross-section ratio σ(W + +c¯¯)/σ(W − + c) is compared to the predictions obtained using parton distribution function parameterisations with different assumptions about the s−s¯¯¯ quark asymmetry

S-adenosylhomocysteine hydrolase deficiency in a human: A genetic disorder of methionine metabolism

We report studies of a Croatian boy, a proven case of human S-adenosylhomocysteine (AdoHcy) hydrolase deficiency. Psychomotor development was slow until his fifth month; thereafter, virtually absent until treatment was started. He had marked hypotonia with elevated serum creatine kinase and transaminases, prolonged prothrombin time and low albumin. Electron microscopy of muscle showed numerous abnormal myelin figures; liver biopsy showed mild hepatitis with sparse rough endoplasmic reticulum. Brain MRI at 12.7 months revealed white matter atrophy and abnormally slow myelination. Hypermethioninemia was present in the initial metabolic study at age 8 months, and persisted (up to 784 μM) without tyrosine elevation. Plasma total homocysteine was very slightly elevated for an infant to 14.5–15.9 μM. In plasma, S-adenosylmethionine was 30-fold and AdoHcy 150-fold elevated. Activity of AdoHcy hydrolase was ≈3% of control in liver and was 5–10% of the control values in red blood cells and cultured fibroblasts. We found no evidence of a soluble inhibitor of the enzyme in extracts of the patient's cultured fibroblasts. Additional pretreatment abnormalities in plasma included low concentrations of phosphatidylcholine and choline, with elevations of guanidinoacetate, betaine, dimethylglycine, and cystathionine. Leukocyte DNA was hypermethylated. Gene analysis revealed two mutations in exon 4: a maternally derived stop codon, and a paternally derived missense mutation. We discuss reasons for biochemical abnormalities and pathophysiological aspects of AdoHcy hydrolase deficiency

Dark Energy Survey Year 1 results: cosmological constraints from galaxy clustering and weak lensing

We present cosmological results from a combined analysis of galaxy clustering and weak gravitational lensing, using 1321 deg 2 of griz imaging data from the first year of the Dark Energy Survey (DES Y1). We combine three two-point functions: (i) the cosmic shear correlation function of 26 million source galaxies in four redshift bins, (ii) the galaxy angular autocorrelation function of 650,000 luminous red galaxies in five redshift bins, and (iii) the galaxy-shear cross-correlation of luminous red galaxy positions and source galaxy shears. To demonstrate the robustness of these results, we use independent pairs of galaxy shape, photometric redshift estimation and validation, and likelihood analysis pipelines. To prevent confirmation bias, the bulk of the analysis was carried out while blind to the true results; we describe an extensive suite of systematics checks performed and passed during this blinded phase. The data are modeled in flat Λ CDM and w CDM cosmologies, marginalizing over 20 nuisance parameters, varying 6 (for Λ CDM) or 7 (for w CDM) cosmological parameters including the neutrino mass density and including the 457 × 457 element analytic covariance matrix. We find consistent cosmological results from these three two-point functions, and from their combination obtain S 8 ≡σ 8 (Ω m /0.3) 0.5 =0.783 +0.021 −0.025 and Ω m =0.264 +0.032 −0.019 for Λ CDM for w CDM, we find S 8 =0.794 +0.029 −0.027, Ω m =0.279 +0.043 −0.022, and w=−0.80 +0.20 −0.22 at 68% CL. The precision of these DES Y1 results rivals that from the Planck cosmic microwave background measurements, allowing a comparison of structure in the very early and late Universe on equal terms. Although the DES Y1 best-fit values for S 8 and Ω m are lower than the central values from Planck