Altered serological and cellular reactivity to H-2 antigens after target cell infection with vaccinia virus

MICE generate cytotoxic T lymphocytes (CTL) which are able to lyse virus infected target cells in vitro after infection with lymphocytic choriomeningitis virus (LCMV) and pox-viruses1−3. CTL kill syngeneic and semiallogenic infected cells but not allogenic infected targets. Target cell lysis in these systems seems to be restricted by H-2 antigens, especially by the K or D end of the major histocompatibility complex (MHC). In experiments where virus specific sensitised lymphocytes kill virus infected allogenic target cells4 the effector lymphocytes have not been characterised exactly. Recent investigations suggest that the active cell in this assay, at least in the measles infection, is a non-thymus derived cell (H. Kreth, personal communication). An H-2 restriction of cell mediated cytolysis (CMC) to trinitrophenol (TNP)-modified lymphocytes has also been described5. Zinkernagel and Doherty6 postulated that the CTL is directed against syngeneic H-2 antigens and viral antigens and they suggested an alteration of H-2 induced by the LCMV infection. Earlier7 we found a close topological relationship between H-2 antigens and the target antigen(s) responsible for CMC in the vaccinia system. Here we report experiments which were carried out to prove alteration of H-2 after infection of L-929 fibroblasts with vaccinia virus

Compromising the 19S proteasome complex protects cells from reduced flux through the proteasome

Proteasomes are central regulators of protein homeostasis in eukaryotes. Proteasome function is vulnerable to environmental insults, cellular protein imbalance and targeted pharmaceuticals. Yet, mechanisms that cells deploy to counteract inhibition of this central regulator are little understood. To find such mechanisms, we reduced flux through the proteasome to the point of toxicity with specific inhibitors and performed genome-wide screens for mutations that allowed cells to survive. Counter to expectation, reducing expression of individual subunits of the proteasome's 19S regulatory complex increased survival. Strong 19S reduction was cytotoxic but modest reduction protected cells from inhibitors. Protection was accompanied by an increased ratio of 20S to 26S proteasomes, preservation of protein degradation capacity and reduced proteotoxic stress. While compromise of 19S function can have a fitness cost under basal conditions, it provided a powerful survival advantage when proteasome function was impaired. This means of rebalancing proteostasis is conserved from yeast to humans

High sensitivity X-ray phase contrast imaging by laboratory grating-based interferometry at high Talbot order geometry

X-ray phase contrast imaging is a powerful analysis technique for materials science and biomedicine. Here, we report on laboratory grating-based X-ray interferometry employing a microfocus X-ray source and a high Talbot order (35th) asymmetric geometry to achieve high angular sensitivity and high spatial resolution X-ray phase contrast imaging in a compact system (total length <1 m). The detection of very small refractive angles (∼50 nrad) at an interferometer design energy of 19 keV was enabled by combining small period X-ray gratings (1.0, 1.5 and 3.0 µm) and a single-photon counting X-ray detector (75 µm pixel size). The performance of the X-ray interferometer was fully characterized in terms of angular sensitivity and spatial resolution. Finally, the potential of laboratory X-ray phase contrast for biomedical imaging is demonstrated by obtaining high resolution X-ray phase tomographies of a mouse embryo embedded in solid paraffin and a formalin-fixed full-thickness sample of human left ventricle in water with a spatial resolution of 21.5 µm

Multiparametric Assessment of Right Ventricular Dysfunction in Heart Failure: An Analysis From PARAGON-HF.

This study aims to characterize right ventricular dysfunction (RVD) in heart failure (HF) with preserved ejection fraction and understand the cumulative prognostic value of abnormal RV echocardiographic parameters in HF with preserved ejection fraction. Data from 809 patients in the PARAGON-HF (Prospective Comparison of Angiotensin Receptor-Neprilysin Inhibitor With Angiotensin-Receptor Blocker Global Outcomes in HF With Preserved Ejection Fraction) echocardiographic substudy (55% women, mean age 74±8 years) were analyzed. Correlates of RVD (defined as tricuspid annular plane systolic excursion &lt;1.7 cm, fractional area change &lt;35% or absolute RV free wall longitudinal strain &lt;20%) were identified using multivariable logistic regression models. We further assessed the prognostic value of the number of abnormal RV parameters (0, 1, ≥2) on total HF hospitalizations (HFH) and cardiovascular death, total HFH, first HFH or cardiovascular death, all-cause death, and cardiovascular death. RVD was identified in 461 (57%) patients. Correlates of RVD included older age, higher heart rate, atrial fibrillation/flutter, greater left ventricle wall thickness, higher N-terminal pro-B-type natriuretic peptide levels, lower systolic blood pressure, and lower left ventricle absolute global longitudinal strain. These results were consistent across sexes, except atrial fibrillation/flutter and LV wall thickness, which were associated with a higher risk of RVD in men but not in women. Participants with ≥2 abnormal RV parameters had a significantly higher adjusted risk of total HFH and cardiovascular death (rate ratio, 2.13 [95% CI, 1.13-4.01]), first HFH or cardiovascular death, all-cause death, and cardiovascular death. Conversely, an isolated abnormal RV parameter was not associated with a worse outcome. RV measures may underestimate the burden of RVD in HF with preserved ejection fraction when considered in isolation. Clinicians should consider multiple dimensions to comprehensively assess RV function in patients with HF with preserved ejection fraction

Repositioning of the humeral tuberosities can be guided by pectoralis major insertion

In complex proximal humerus fractures, positioning of the tuberosities can be a challenge. This study demonstrates the constant angle between the pectoralis major (PM) and the medial lip of the bicipital groove (BG) on the horizontal axial plane. This angle can be used to determine the rotation, as well as the positioning of the tuberosities, when planning a hemiarthroplasty or a reconstruction. Thirty-one shoulder MRIs were reviewed by three independent observers. The measurements were taken by superposing the axial cut of the proximal humerus, at the level of the distal bicipital groove, and the cut at the top of the PM insertion. By aligning the centers of rotation, we could determine the arcs of rotation between the insertion of the PM and the lips of the medial and lateral bicipital groove (MBG and LBG). Both angles were compared in terms of reliability, reproducibility, and precision. The mean PM–MBG angle was 3.7° [standard deviation (SD) 14.7°] and 27.4° (SD 14.4°) for the PM–LBG angle. We obtained good and very good intra-class correlation coefficient (ICC) results for inter- (0.675) and intra-observer (0.793) reliabilities on the medial angle, plus excellent results for the lateral angle (inter-observers 0.962 and intra-observer 0.895). This study demonstrates that the repositioning of humeral tuberosities can be guided by pectoralis major insertion. This will help achieve proper positioning of the metaphysis in relation to the diaphysis during surgery for complex proximal humerus fractures

Clinical implications of subclinical left ventricular dysfunction in heart failure with preserved ejection fraction:The PARAGON-HF study

Aims: Left ventricular (LV) subclinical impairment has been described in heart failure with preserved ejection fraction (HFpEF). We assessed the relationship between LV myocardial deformation by strain imaging and recurrent hospitalization for heart failure (HF) or cardiovascular death in a large international HFpEF population. Methods and results: We assessed two-dimensional speckle-tracking based global longitudinal strain (GLS) in 790 patients (mean age 74 ± 8 years, 54% female) with adequate image quality enrolled in the PARAGON-HF echocardiography study. We examined the relationship of GLS with total HF hospitalizations and cardiovascular death (the primary composite outcome) after accounting for clinical confounders. Approximately 47% of the population had evidence of LV subclinical dysfunction, defined as absolute GLS &lt;16%. Impaired GLS was significantly associated with higher values of circulating baseline N-terminal pro-B-type-natriuretic peptide. After a median follow-up of 3.0 years, there were 407 total HF hospitalizations and cardiovascular deaths. After multivariable adjustment, worse GLS was associated with a greater risk for the primary composite outcome (adjusted hazard ratio per 1% decrease: 1.06; 95% confidence interval 1.02–1.11; p = 0.008). GLS did not modify the treatment effect of sacubitril/valsartan compared with valsartan for the composite outcome (p for interaction &gt;0.1). Conclusions: In a large HFpEF population, impaired LV function was observed even among patients with preserved ejection fraction, and was associated with an increased risk of total HF hospitalizations or cardiovascular death, accounting for clinical confounders. These findings highlight the key role of subtle LV systolic impairment in the pathophysiology of HFpEF.</p

Interleukin-6 and Cardiovascular Events in Healthy Adults:MESA

Background: Elevated interleukin (IL)-6 levels have been linked to adverse outcomes in patients with and without baseline cardiovascular disease (CVD). Objectives: The purpose of this study was to examine the association between circulating IL-6 levels and CVD events without baseline CVD across racial and ethnic groups. Methods: We conducted an observational analysis utilizing the MESA (Multi-Ethnic Study of Atherosclerosis), a multicenter, prospective community-based study of CVD at baseline from four racial and ethnic groups. IL-6 levels were measured at the time of enrollment (visit 1) and were divided into 3 terciles. Patient baseline characteristics and outcomes, including all-cause mortality, CV mortality, heart failure, and non-CV mortality, were included. Cox proportional hazard regression models were used to assess associations between IL-6 levels and study outcomes with IL-6 tercile 1 as reference. Results: Of 6,622 individuals, over half were women (53%) with a median age of 62 (IQR: 53-70) years. Racial and ethnic composition was non-Hispanic White (39%) followed by African American (27%), Hispanic (22%), and Chinese American (12%). Compared to tercile 1, participants with IL-6 tercile 3 had a higher adjusted risk of and all-cause mortality (HR: 1.98 [95% CI: 1.67-2.36]), CV mortality (HR: 1.55 [95% CI: 1.05-2.30]), non-CV mortality (HR: 2.05 [95% CI: 1.65-2.56]), and heart failure (HR: 1.48 [95% CI: 0.99-2.19]). When tested as a continuous variable, higher levels of IL-6 were associated with an increased risk of all individual outcomes. Compared to non-Hispanic White participants, the unadjusted and adjusted risk of all outcomes across all races and ethnicities was similar across all IL-6 terciles. Conclusions: High levels of circulating IL-6 are associated with worse CV outcomes and increased all-cause mortality consistently across all racial and ethnic groups.</p

Dietary sodium and fluid intake in heart failure. A clinical consensus statement of the Heart Failure Association of the ESC

Sodium and fluid restriction has traditionally been advocated in patients with heart failure (HF) due to their sodium and water avid state. However, most evidence regarding the altered sodium handling, fluid homeostasis and congestion-related signs and symptoms in patients with HF originates from untreated patient cohorts and physiological investigations. Recent data challenge the beneficial role of dietary sodium and fluid restriction in HF. Consequently, the European Society of Cardiology HF guidelines have gradually downgraded these recommendations over time, now advising for the limitation of salt intake to no more than 5 g/day in patients with HF, while contemplating fluid restriction of 1.5–2 L/day only in selected patients. Therefore, the objective of this clinical consensus statement is to provide advice on fluid and sodium intake in patients with acute and chronic HF, based on contemporary evidence and expert opinion.</p

ACE2 is the critical in vivo receptor for SARS-CoV-2 in a novel COVID-19 mouse model with TNF-and IFN?-driven immunopathology

Despite tremendous progress in the understanding of COVID-19, mechanistic insight into immunological, disease-driving factors remains limited. We generated maVie16, a mouse-adapted SARS-CoV-2, by serial passaging of a human isolate. In silico modeling revealed how only three Spike mutations of maVie16 enhanced interaction with murine ACE2. maVie16 induced profound pathology in BALB/c and C57BL/6 mice, and the resulting mouse COVID-19 (mCOVID-19) replicated critical aspects of human disease, including early lymphopenia, pulmonary immune cell infiltration, pneumonia, and specific adaptive immunity. Inhibition of the proinflammatory cyto-kines IFN? and TNF substantially reduced immunopathology. Importantly, genetic ACE2-deficiency completely prevented mCOVID-19 development. Finally, inhalation therapy with recombinant ACE2 fully protected mice from mCOVID-19, revealing a novel and efficient treatment. Thus, we here present maVie16 as a new tool to model COVID-19 for the discovery of new therapies and show that disease severity is determined by cytokine-driven immunopathology and critically dependent on ACE2 in vivo. © Gawish et al

Effects of Sacubitril-Valsartan, versus Valsartan, in Women Compared to Men with Heart Failure and Preserved Ejection Fraction: Insights from PARAGON-HF

Unlike heart failure with reduced ejection fraction, there is no approved treatment for heart failure with preserved ejection fraction (HFpEF), the predominant phenotype in women. Therefore, there is a greater heart failure therapeutic deficit in women, compared with men. In a pre-specified subgroup analysis, we examined outcomes according to sex in the PARAGON-HF trial which compared sacubitril-valsartan and valsartan in patients with HFpEF. The primary outcome was a composite of first and recurrent hospitalizations for heart failure and death from cardiovascular causes. We also report secondary efficacy and safety outcomes. Overall, 2479 women (51.7%) and 2317 men (48.3%) were randomized. Women were older, had more obesity, less coronary disease, and lower estimated glomerular filtration rate and NT-proBNP levels than men. For the primary outcome, the rate ratio for sacubitril-valsartan versus valsartan was 0.73 (95% CI 0.59-0.90) in women and 1.03 (0.84-1.25) in men; P interaction=0.017. The benefit from sacubitril-valsartan was due to reduction in heart failure hospitalization. The improvement in NYHA class and renal function with sacubitril-valsartan was similar in women and men, whereas the improvement in KCCQ-CSS was less in women than in men. The difference in adverse events, between sacubitril-valsartan and valsartan, was similar in women and men. As compared with valsartan, sacubitril-valsartan seemed to reduce the risk of heart failure hospitalization more in women than in men. While the possible sex-related modification of the effect of treatment has several potential explanations, the present study does not provide a definite mechanistic basis for this finding. URL: https://clinicaltrials.gov Unique Identifier: NCT01920711