750 research outputs found

    Localized amyloidosis presenting with a penile mass: a case report

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    Amyloidosis is a disease characterized by the deposition of altered proteins in tissues. Amyloid deposition always occurs in the extracellular matrix and presents a fibrillary conformation. Local deposition of amyloid may occur in individual organs, without systemic involvement. We report here a rare case of localized penile shaft amyloidosis--an unusual location for amyloid deposition--presenting as a penile mass that resulted in a urethral stricture in 37-year old male patient. We have also comprehensively reviewed the literature regarding localized amyloidosis

    Left atrial structure and function in cardiac amyloidosis

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    Aims: Although cardiac amyloidosis (CA) is characterized by significant left atrial (LA) dilatation, the characteristics of LA function remain to be fully investigated. // Methods and results: We assessed LA function by speckle-tracking echocardiography in 124 patients with CA and sinus rhythm: 68 with light chain (AL), 29 with mutant (ATTRm), 27 with wild-type (ATTRwt) transthyretin amyloidosis. Conventional and strain-derived parameters, including LA peak longitudinal strain (LS) and strain rate (peak LSR: reservoir function; early LSR: conduit function; late LSR: active function), were assessed compared between CA patients and 20 healthy controls of similar age and gender. All LA function phases, including LA longitudinal strain, peak LSR, early and late LSR were significantly impaired in CA compared to healthy controls after adjusting for LA size, LV ejection fraction and LV filling pressures (E/E’) (all P < 0.05). Peak LA LS was moderately correlated with LV global LS (R = −0.60, P < 0.001); late LSR was correlated with A wave at the level of LV inflow (R = −0.69, P < 0.001). Among the different CA subtypes, peak LS and LA active emptying fraction were worse in ATTRwt than AL and ATTRm [P < 0.05 after adjustment for age, sex, body mass index, systolic blood pressure, heart rate, LA volume index, severity of mitral regurgitation, left ejection fraction, and left ventricular end-diastolic pressure (E/E’)]. // Conclusion: In CA, LA function was severely impaired and highly correlated with LV deformation. Differences in LA function between amyloid subtypes suggest that amyloid aetiology plays a role in the pathophysiology of cardiac dysfunction in CA

    Left atrial structure and function in cardiac amyloidosis

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    Aims: Although cardiac amyloidosis (CA) is characterized by significant left atrial (LA) dilatation, the characteristics of LA function remain to be fully investigated. // Methods and results: We assessed LA function by speckle-tracking echocardiography in 124 patients with CA and sinus rhythm: 68 with light chain (AL), 29 with mutant (ATTRm), 27 with wild-type (ATTRwt) transthyretin amyloidosis. Conventional and strain-derived parameters, including LA peak longitudinal strain (LS) and strain rate (peak LSR: reservoir function; early LSR: conduit function; late LSR: active function), were assessed compared between CA patients and 20 healthy controls of similar age and gender. All LA function phases, including LA longitudinal strain, peak LSR, early and late LSR were significantly impaired in CA compared to healthy controls after adjusting for LA size, LV ejection fraction and LV filling pressures (E/E’) (all P < 0.05). Peak LA LS was moderately correlated with LV global LS (R = −0.60, P < 0.001); late LSR was correlated with A wave at the level of LV inflow (R = −0.69, P < 0.001). Among the different CA subtypes, peak LS and LA active emptying fraction were worse in ATTRwt than AL and ATTRm [P < 0.05 after adjustment for age, sex, body mass index, systolic blood pressure, heart rate, LA volume index, severity of mitral regurgitation, left ejection fraction, and left ventricular end-diastolic pressure (E/E’)]. // Conclusion: In CA, LA function was severely impaired and highly correlated with LV deformation. Differences in LA function between amyloid subtypes suggest that amyloid aetiology plays a role in the pathophysiology of cardiac dysfunction in CA

    Phase 3 Multicenter Study of Revusiran in Patients with Hereditary Transthyretin-Mediated (hATTR) Amyloidosis with Cardiomyopathy (ENDEAVOUR)

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    PURPOSE: The Phase 3 ENDEAVOUR study evaluated revusiran, an investigational RNA interference therapeutic targeting hepatic transthyretin (TTR) production, for treating cardiomyopathy caused by hereditary transthyretin-mediated (hATTR) amyloidosis. / METHODS: Patients with hATTR amyloidosis with cardiomyopathy were randomized 2:1 to receive subcutaneous daily revusiran 500 mg (n = 140) or placebo (n = 66) for 5 days over a week followed by weekly doses. Co-primary endpoints were 6-min walk test distance and serum TTR reduction. / RESULTS: Revusiran treatment was stopped after a median of 6.71 months; the study Sponsor prematurely discontinued dosing due to an observed mortality imbalance between treatment arms. Eighteen (12.9%) patients on revusiran and 2 (3.0%) on placebo died during the on-treatment period. Most deaths in both treatment arms were adjudicated as cardiovascular due to heart failure (HF), consistent with the natural history of the disease. A post hoc safety investigation of patients treated with revusiran found that, at baseline, a greater proportion of those who died were ≥ 75 years and showed clinical evidence of more advanced HF compared with those who were alive throughout treatment. Revusiran pharmacokinetic exposures and TTR lowering did not show meaningful differences between patients who died and who were alive. Revusiran did not deleteriously affect echocardiographic parameters, cardiac biomarkers, or frequency of cardiovascular and HF hospitalization events. / CONCLUSIONS: Causes for the observed mortality imbalance associated with revusiran were thoroughly investigated and no clear causative mechanism could be identified. Although the results suggest similar progression of cardiac parameters in both treatment arms, a role for revusiran cannot be excluded. / CLINICAL TRIAL REGISTRATION: NCT02319005

    Subcomplex Iλ Specifically Controls Integrated Mitochondrial Functions in Caenorhabditis elegans

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    Complex I dysfunction is a common, heterogeneous cause of human mitochondrial disease having poorly understood pathogenesis. The extensive conservation of complex I composition between humans and Caenorhabditis elegans permits analysis of individual subunit contribution to mitochondrial functions at both the whole animal and mitochondrial levels. We provide the first experimentally-verified compilation of complex I composition in C. elegans, demonstrating 84% conservation with human complex I. Individual subunit contribution to mitochondrial respiratory capacity, holocomplex I assembly, and animal anesthetic behavior was studied in C. elegans by RNA interference-generated knockdown of nuclear genes encoding 28 complex I structural subunits and 2 assembly factors. Not all complex I subunits directly impact respiratory capacity. Subcomplex Iλ subunits along the electron transfer pathway specifically control whole animal anesthetic sensitivity and complex II upregulation, proportionate to their relative impairment of complex I-dependent oxidative capacity. Translational analysis of complex I dysfunction facilitates mechanistic understanding of individual gene contribution to mitochondrial disease. We demonstrate that functional consequences of complex I deficiency vary with the particular subunit that is defective

    Field-study science classrooms as positive and enjoyable learning environments

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    We investigated differences between field-study classrooms and traditional science classrooms in terms of the learning environment and students’ attitudes to science, as well as the differential effectiveness of field-study classrooms for students differing in sex and English proficiency. A modified version of selected scales from the What Is Happening In this Class? questionnaire was used to assess the learning environment, whereas students’ attitudes were assessed with a shortened version of a scale from the Test of Science Related Attitudes. A sample of 765 grade 5 students from 17 schools responded to the learning environment and attitude scales in terms of both their traditional science classrooms and classrooms at a field-study centre in Florida. Large effect sizes supported the effectiveness of the field-studies classroom in terms of both the learning environment and student attitudes. Relative to the home school science class, the field-study class was considerably more effective for students with limited English proficiency than for native English speakers

    The Amyloidogenic V122I Transthyretin Variant in Elderly Black Americans

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    BACKGROUND: Approximately 4% of black Americans carry a valine-to-isoleucine substitution (V122I) in the transthyretin protein, which has been associated with late-onset restrictive amyloid cardiomyopathy and increased risks of death and heart failure. METHODS: We determined genotype status for the transthyretin gene (TTR) in 3856 black participants in the Atherosclerosis Risk in Communities study and assessed clinical profiles, mortality, and the risk of incident heart failure in V122I TTR variant carriers (124 participants [3%]) versus noncarriers (3732 participants). Cardiac structure and function and features suggestive of cardiac amyloidosis were assessed in participants who underwent echocardiography during visit 5 (2011 to 2013), when they were older than 65 years of age. RESULTS: After 21.5 years of follow-up, we did not detect a significant difference in mortality between carriers (41 deaths, 33%) and noncarriers (1382 deaths, 37%; age- and sex-stratified hazard ratio among carriers, 0.99; 95% confidence interval [CI], 0.73 to 1.36; P=0.97). The TTR variant was associated with an increased risk of incident heart failure (age- and sex-stratified hazard ratio, 1.47; 95% CI, 1.03 to 2.10; P=0.04). On echocardiography at visit 5, carriers (46 participants) had worse systolic and diastolic function, as well as a higher level of N-terminal pro–brain natriuretic peptide, than noncarriers (1194 participants), although carriers had a low prevalence (7%) of overt manifestations of amyloid cardiomyopathy. CONCLUSIONS: We did not detect a significant difference in mortality between V122I TTR allele carriers and noncarriers, a finding that contrasts with prior observations; however, the risk of heart failure was increased among carriers. The prevalence of overt cardiac abnormalities among V122I TTR carriers was low. (Funded by the National Heart, Lung, and Blood Institute and others.

    What happens if you single out? An experiment

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    We present an experiment investigating the effects of singling out an individual on trust and trustworthiness. We find that (a) trustworthiness falls if there is a singled out subject; (b) non-singled out subjects discriminate against the singled out subject when they are not responsible of the distinct status of this person; (c) under a negative frame, the singled out subject returns significantly less; (d) under a positive frame, the singled out subject behaves bimodally, either selecting very low or very high return rates. Overall, singling out induces a negligible effect on trust but is potentially disruptive for trustworthiness
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