229 research outputs found

    Evaluating the softness of animal fibers

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    Softness is an important property of textile fibers, and animal fibers in particular. At present, there is no reliable method for objectively evaluating fiber softness. This paper examines a simple technique of such evaluations by pulling a bundle of parallel fibers through a series of pins. Softer fibers with lower bending rigidities and smoother surfaces should have lower pulling forces. Alpaca and wool fibers are used in this study to validate this technique, and the results suggest that pulling force measurements can reflect differences in fiber softness

    p31 comet acts to ensure timely spindle checkpoint silencing subsequent to kinetochore attachment

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    The spindle assembly checkpoint links the onset of anaphase to completion of chromosome-microtubule attachment and is mediated by the binding of Mad and Bub proteins to kinetochores of unattached or maloriented chromosomes. Mad2 and BubR1 traffic between kinetochores and the cytosol, thereby transmitting a "wait anaphase" signal to the anaphase-promoting complex. It is generally assumed that this signal dissipates automatically upon kinetochore-microtubule binding, but it has been shown that under conditions of nocodazole-induced arrest p31comet, a Mad2-binding protein, is required for mitotic progression. In this article we investigate the localization and function of p31 comet during normal, unperturbed mitosis in human and marsupial cells. We find that, like Mad2, p31 comet traffics on and off kinetochores and is also present in the cytosol. Cells depleted of p31 comet arrest in metaphase with mature bipolar kinetochore-microtubule attachments, a satisfied checkpoint, and high cyclin B levels. Thus p31 comet is required for timely mitotic exit. We propose that p31 comet is an essential component of the machinery that silences the checkpoint during each cell cycle

    An IRAK1-PIN1 signalling axis drives intrinsic tumour resistance to radiation therapy

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    Drug-based strategies to overcome tumour resistance to radiotherapy (R-RT) remain limited by the single-agent toxicity of traditional radiosensitizers (for example, platinums) and a lack of targeted alternatives. In a screen for compounds that restore radiosensitivity in p53 mutant zebrafish while tolerated in non-irradiated wild-type animals, we identified the benzimidazole anthelmintic oxfendazole. Surprisingly, oxfendazole acts via the inhibition of IRAK1, a kinase thus far implicated in interleukin-1 receptor (IL-1R) and Toll-like receptor (TLR) immune responses. IRAK1 drives R-RT in a pathway involving IRAK4 and TRAF6 but not the IL-1R/TLR-IRAK adaptor MyD88. Rather than stimulating nuclear factor-κB, radiation-activated IRAK1 prevented apoptosis mediated by the PIDDosome complex (comprising PIDD, RAIDD and caspase-2). Countering this pathway with IRAK1 inhibitors suppressed R-RT in tumour models derived from cancers in which TP53 mutations predict R-RT. Moreover, IRAK1 inhibitors synergized with inhibitors of PIN1, a prolyl isomerase essential for IRAK1 activation in response to pathogens and, as shown here, in response to ionizing radiation. These data identify an IRAK1 radiation-response pathway as a rational chemoradiation therapy target

    Candidate genes for field resistance to cassava brown streak disease revealed through the analysis of multiple data sources

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    Open Access JournalCassava (Manihot esculenta Crantz) is a food and industrial storage root crop with substantial potential to contribute to managing risk associated with climate change due to its inherent resilience and in providing a biodegradable option in manufacturing. In Africa, cassava production is challenged by two viral diseases, cassava brown streak disease (CBSD) and cassava mosaic disease. Here we detect quantitative trait loci (QTL) associated with CBSD in a biparental mapping population of a Tanzanian landrace, Nachinyaya and AR37-80, phenotyped in two locations over three years. The purpose was to use the information to ultimately facilitate either marker-assisted selection or adjust weightings in genomic selection to increase the efficiency of breeding. Results from this study were considered in relation to those from four other biparental populations, of similar genetic backgrounds, that were phenotyped and genotyped simultaneously. Further, we investigated the co-localization of QTL for CBSD resistance across populations and the genetic relationships of parents based on whole genome sequence information. Two QTL on chromosome 4 for resistance to CBSD foliar symptoms and one on each of chromosomes 11 and 18 for root necrosis were of interest. Of significance within the candidate genes underlying the QTL on chromosome 4 are Phenylalanine ammonia-lyase (PAL) and Cinnamoyl-CoA reductase (CCR) genes and three PEPR1-related kinases associated with the lignin pathway. In addition, a CCR gene was also underlying the root necrosis-resistant QTL on chromosome 11. Upregulation of key genes in the cassava lignification pathway from an earlier transcriptome study, including PAL and CCR, in a CBSD-resistant landrace compared to a susceptible landrace suggests a higher level of basal lignin deposition in the CBSD-resistant landrace. Earlier RNAscope® in situ hybridisation imaging experiments demonstrate that cassava brown streak virus (CBSV) is restricted to phloem vessels in CBSV-resistant varieties, and phloem unloading for replication in mesophyll cells is prevented. The results provide evidence for the involvement of the lignin pathway. In addition, five eukaryotic initiation factor (eIF) genes associated with plant virus resistance were found within the priority QTL regions

    Cardio-Renal-Metabolic Overlap, Outcomes, and Dapagliflozin in Heart Failure With Mildly Reduced or Preserved Ejection Fraction

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    Background: Cardio-renal-metabolic (CRM) conditions are individually common among patients with heart failure (HF), but the prevalence and influence of overlapping CRM conditions in this population have not been well-studied. Objectives: This study aims to evaluate the impact of overlapping CRM conditions on clinical outcomes and treatment effects of dapagliflozin in HF. Methods: In this post hoc analysis of DELIVER (Dapagliflozin Evaluation to Improve the Lives of Patients With Preserved Ejection Fraction Heart Failure), we evaluated the prevalence of comorbid CRM conditions (atherosclerotic cardiovascular disease, chronic kidney disease, and type 2 diabetes), their impact on the primary outcome (cardiovascular death or worsening HF), and treatment effects of dapagliflozin by CRM status. Results: Among 6,263 participants, 1,952 (31%), 2,245 (36%), and 1,236 (20%) had 1, 2, and 3 additional CRM conditions, respectively. HF alone was uncommon (13%). Greater CRM multimorbidity was associated with older age, higher body mass index, longer-duration HF, worse health status, and lower left ventricular ejection fraction. Risk of the primary outcome increased with higher CRM overlap, with 3 CRM conditions independently associated with highest risk of primary events (adjusted HR: 2.16 [95% CI: 1.72-2.72]; P &lt; 0.001) compared with HF alone. Relative benefits of dapagliflozin on the primary outcome were consistent irrespective of the type of CRM overlap (Pinteraction = 0.773) and by the number of CRM conditions (Pinteraction = 0.734), with greatest absolute benefits among those with highest CRM multimorbidity. Estimated 2-year numbers needed to treat with dapagliflozin to prevent 1 primary event were approximately 52, 39, 33, and 24 for participants with 0, 1, 2, and 3 additional CRM conditions at baseline, respectively. Adverse events between treatment arms were similar across the CRM spectrum. Conclusions: CRM multimorbidity was common and associated with adverse outcomes among patients with HF and left ventricular ejection fraction &gt;40% in DELIVER. Dapagliflozin was safe and effective across the CRM spectrum, with greater absolute benefits among those with highest CRM overlap (Dapagliflozin Evaluation to Improve the LIVEs of Patients With Preserved Ejection Fraction Heart Failure [DELIVER]; NCT03619213).</p

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

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    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

    Effects of sacubitril/valsartan on N-terminal pro-B-type natriuretic peptide in heart failure with preserved ejection fraction

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    Objectives: The authors sought to evaluate the prognostic significance of baseline N-terminal pro–B-type natriuretic peptide (NT-proBNP), whether NT-proBNP modified the treatment response to sacubitril/valsartan, and the treatment effect of sacubitril/valsartan on NT-proBNP overall and in key subgroups. Background: Sacubitril/valsartan reduces NT-proBNP in heart failure (HF) with both reduced and preserved ejection fraction (EF), but did not significantly reduce total HF hospitalizations and cardiovascular death compared with valsartan in patients with HF with preserved EF (HFpEF). Methods: In the PARAGON-HF (Efficacy and Safety of LCZ696 Compared to Valsartan, on Morbidity and Mortality in Heart Failure Patients With Preserved Ejection Fraction) trial, 4,796 patients with HFpEF and elevated NT-proBNP were randomized to sacubitril/valsartan or valsartan. NT-proBNP was measured at screening in all patients and at 5 subsequent times in &gt;2,700 patients: before, between, and after sequential valsartan and sacubitril/valsartan run-in periods, and 16 and 48 weeks post-randomization. Results: Median NT-proBNP was 911 pg/ml (interquartile range: 464 to 1,613 pg/ml) at screening. Screening NT-proBNP was strongly associated with the primary endpoint, total HF hospitalizations and cardiovascular death (rate ratio [RR]: 1.68 per log increase in NT-proBNP, 95% confidence interval [CI]: 1.53 to 1.85; p &lt; 0.001). This relationship was stronger in patients with atrial fibrillation (adjusted RR: 2.33 [95% CI: 1.89 to 2.87] vs. 1.58 [95% CI: 1.42 to 1.75] in patients without atrial fibrillation; p interaction &lt;0.001) and weaker in obese patients (adjusted RR: 1.50 [95% CI: 1.31 to 1.71] vs. 1.92 [95% CI: 1.70 to 2.17] in nonobese patients; p interaction &lt;0.001). Screening NT-proBNP did not modify the treatment effect of sacubitril/valsartan compared with valsartan (p interaction = 0.96). Sacubitril/valsartan reduced NT-proBNP by 19% (95% CI: 14% to 23%; p &lt; 0.001) compared with valsartan 16 weeks post-randomization, with similar reductions in men (20%) and women (18%), and in patients with left ventricular EF ≤57% (20%) and &gt;57% (18%). Decreases in NT-proBNP predicted lower subsequent risk of the primary endpoint. Conclusions: Baseline NT-proBNP predicted HF events but did not modify the sacubitril/valsartan treatment effect in patients with HFpEF. Sacubitril/valsartan reduced NT-proBNP consistently in men and women, and in patients with lower or higher EF. (Efficacy and Safety of LCZ696 Compared to Valsartan, on Morbidity and Mortality in Heart Failure Patients With Preserved Ejection Fraction [PARAGON-HF]; NCT01920711

    Heart failure, peripheral artery disease, and dapagliflozin:A patient-level meta-analysis of DAPA-HF and DELIVER

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    Aims: Because an increased risk of amputation with canagliflozin was reported in the CANVAS trials, there has been a concern about the safety of sodium-glucose cotransporter 2 inhibitors in patients with peripheral artery disease (PAD) who are at higher risk of amputation. Methods and results: A patient-level pooled analysis of the DAPA-HF and DELIVER trials, which evaluated the efficacy and safety of dapagliflozin in patients with heart failure (HF) with reduced, mildly reduced/preserved ejection fraction, respectively, was conducted. In both trials, the primary outcome was the composite of worsening HF or cardiovascular death, and amputation was a prespecified safety outcome. Peripheral artery disease history was available for 11 005 of the total 11 007 patients. Peripheral artery disease was reported in 809 of the 11 005 patients (7.4%). Median follow-up was 22 months (interquartile range 17-30). The rate of the primary outcome (per 100 person-years) was higher in PAD patients than that in non-PAD patients: 15.1 [95% confidence interval (CI) 13.1-17.3) vs. 10.6 (10.2-11.1]; adjusted hazard ratio 1.23 (95% CI 1.06-1.43). The benefit of dapagliflozin on the primary outcome was consistent in patients with [hazard ratio 0.71 (95% CI 0.54-0.94)] and without PAD [0.80 (95% CI 0.73-0.88)] (Pinteraction = 0.39). Amputations, while more frequent in PAD patients, were not more common with dapagliflozin, compared with placebo, irrespective of PAD status (PAD, placebo 4.2% vs. dapagliflozin 3.7%; no PAD, placebo 0.4% vs. dapagliflozin 0.4%) (Pinteraction = 1.00). Infection rather than ischaemia was the main trigger for amputation, even in patients with PAD. Conclusion: The risk of worsening HF or cardiovascular death was higher in patients with PAD, as was the risk of amputation. The benefits of dapagliflozin were consistent in patients with and without PAD, and dapagliflozin did not increase the risk of amputation.</p

    Heart Failure, Investigator-Reported Sleep Apnea and Dapagliflozin:A Patient-Level Pooled Meta-Analysis of DAPA-HF and DELIVER

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    Background: Sleep apnea is more common in patients with heart failure (HF) than in the general population, but little is known about its association with clinical outcomes in various HF phenotypes or how it might modify the effect of HF therapy. Objectives: To examine the prevalence of sleep apnea, its association with outcomes and the effects of dapagliflozin in patients with HF with and without sleep apnea in a pooled analysis of 2 trials comparing dapagliflozin to placebo in HFrEF (DAPA-HF trial) and HFmrEF/HFpEF (DELIVER trial). Methods: A history of sleep apnea was investigator-reported. The primary outcome was a composite of worsening HF or cardiovascular death. Results: The prevalence of sleep apnea was 5.7% and 7.8% in patients with HFrEF and HFmrEF/HFpEF, respectively. The primary outcome occurred at a rate of 16.0 in participants with sleep apnea compared to 10.6 per 100 person-years in those without (adjusted HR 1.29 [95%CI, 1.10–1.52]). Compared with placebo, dapagliflozin reduced the risk of the primary endpoint to the same extent in patients with (HR 0.78 [95% CI, 0.59–1.03]) and without sleep apnea (HR 0.79 [0.72–0.87]) [Pinteraction = 0.93]. The beneficial effects of dapagliflozin on other clinical outcomes and symptom burden, physical function, and quality of life were consistent in participants with and without sleep apnea. Conclusions: In DAPA-HF and DELIVER, the true prevalence of sleep apnea was likely underestimated. An investigator-reported history of sleep apnea was associated with higher rates of worsening HF events. The benefits of dapagliflozin on clinical outcomes were consistent in patients with and without sleep apnea. Clinical trial registration: Unique identifiers: NCT01920711 Condensed Abstract: In a pooled analysis of the DAPA-HF and DELIVER trials of more than 11,000 patients with heart failure (HF) across the range of ejection fractions, an investigator-reported history of sleep apnea was associated with higher rates of worsening HF events but not mortality. The beneficial effects of dapagliflozin on clinical outcomes were consistent in patients with and without sleep apnea. These findings provide further evidence for dapagliflozin as a new treatment option for patients with heart failure across the range of ejection fractions.</p

    The effect of sacubitril/valsartan on left ventricular myocardial deformation in heart failure with preserved ejection fraction (PARAMOUNT trial)

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    Background: Global longitudinal strain (GLS) and global circumferential strain (GCS) have been shown to be impaired in heart failure with preserved ejection fraction. We sought to assess whether treating patients with heart failure with preserved ejection fraction with sacubitril/valsartan would significantly improve GLS and GCS compared with valsartan alone. Methods and Results: PARAMOUNT (Prospective Comparison of ARNI With ARB on Management of Heart Failure With Preserved Ejection Fraction Trial) was a phase II, randomized, parallel-group, double-blind multicenter trial in 301 patients with New York Heart Association functional class II–III heart failure, a left ventricular ejection fraction of 45%, and an N-terminal pro-B-type natriuretic peptide of ≥400 pg/mL. Participants were randomly assigned (1:1) to sacubitril/valsartan titrated to 200 mg twice daily or valsartan titrated to 160 mg twice daily for 36 weeks. We assessed changes in the GLS and the GCS from baseline to 36 weeks, adjusting for baseline value, in patients with sufficient imaging quality for 2-dimensitonal speckle tracking analysis at both timepoints (n = 60 sacubitril/valsartan, n = 75 valsartan only). GCS was significantly improved at 36 weeks in the sacubitril/valsartan group when compared with the valsartan group (Δ4.42%, 95% confidence interval [CI] 0.67–8.17, P = .021), with no significant difference observed in GLS (Δ0.25%, 95% CI, –1.19 to 1.70, P = .73). Patients with a history of hospitalization for heart failure had a differentially greater improvement in GCS when treated with sacubitril/valsartan. Conclusions: In patients with heart failure with preserved ejection fraction, sacubitril/valsartan improved GCS but not GLS when compared with valsartan during a 36-week period
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