467 research outputs found
Time dependence of starch levels in the sapwood of Eucalyptus diversicolor (Karri) as: standing trees, stored saw-Logs, ringbarked trees and trees felled without lopping
The spread of Lyctus brunneus (powder post borer) throughout South Western Australia has lead to a need for Information on Starch levels in the sapwood of Eucalyptus diversicolor (Karri). Karri is one of the most commonly used structural timbers in Western Australia. Rates of starch depletion in stored Karri logs were determined, those in dry stored logs were found to be greater than those stored under an intermittent water spray regime. Starch levels in living, Standing Kam were measured and found to be strongly influenced by rainfall. Starch levels in ringbarked (girdled) trees declined more rapidly than those felled and left with an intact crown. A standard colorimetric technique for starch analysis was used. While high relative precision is possible, assumptions in this and similar methods make them unsuitable for absolute estimations of the two components of starch, amylose and amylopectin. Possible alternative methods are discussed
The influence of hypoxia and energy depletion on the response of endothelial cells to the vascular disrupting agent combretastatin A-4-phosphate
Combretastatin A-4 phosphate (CA4P) is a microtubule-disrupting tumour-selective vascular disrupting agent (VDA). CA4P activates the actin-regulating RhoA-GTPase/ ROCK pathway, which is required for full vascular disruption. While hypoxia renders tumours resistant to many conventional therapies, little is known about its influence on VDA activity. Here, we found that active RhoA and ROCK effector phospho-myosin light chain (pMLC) were downregulated in endothelial cells by severe hypoxia. CA4P failed to activate RhoA/ROCK/pMLC but its activity was restored upon reoxygenation. Hypoxia also inhibited CA4P-mediated actinomyosin contractility, VE-cadherin junction disruption and permeability rise. Glucose withdrawal downregulated pMLC, and coupled with hypoxia, reduced pMLC faster and more profoundly than hypoxia alone. Concurrent inhibition of glycolysis (2-deoxy-D-glucose, 2DG) and mitochondrial respiration (rotenone) caused profound actin filament loss, blocked RhoA/ROCK signalling and rendered microtubules CA4P-resistant. Withdrawal of the metabolism inhibitors restored the cytoskeleton and CA4P activity. The AMP-activated kinase AMPK was investigated as a potential mediator of pMLC downregulation. Pharmacological AMPK activators that generate AMP, unlike allosteric activators, downregulated pMLC but only when combined with 2DG and/or rotenone. Altogether, our results suggest that Rho/ROCK and actinomyosin contractility are regulated by AMP/ATP levels independently of AMPK, and point to hypoxia/energy depletion as potential modifiers of CA4P response
A computational analysis of lower bounds for big bucket production planning problems
In this paper, we analyze a variety of approaches to obtain lower bounds for multi-level production planning problems with big bucket capacities, i.e., problems in which multiple items compete for the same resources. We give an extensive survey of both known and new methods, and also establish relationships between some of these methods that, to our knowledge, have not been presented before. As will be highlighted, understanding the substructures of difficult problems provide crucial insights on why these problems are hard to solve, and this is addressed by a thorough analysis in the paper. We conclude with computational results on a variety of widely used test sets, and a discussion of future research
Infections in Dupilumab Clinical Trials in Atopic Dermatitis : A Comprehensive Pooled Analysis
Background: Patients with moderate-to-severe atopic dermatitis (AD) have increased infection risk, including skin infections and systemic infections. Immunomodulators (e.g., anti-tumor necrosis factors, anti-interleukin [anti-IL]-23, anti-IL-17, Janus kinase inhibitors) increase risk of infections. Dupilumab (a monoclonal antibody blocking the shared receptor component for IL-4 and IL-13) is approved for inadequately controlled moderate-to-severe AD and for moderate-to-severe eosinophilic or oral corticosteroid-dependent asthma. Objective: The aim was to determine the impact of dupilumab on infection rates in patients with moderate-to-severe AD. Methods: This analysis pooled data from seven randomized, placebo-controlled dupilumab trials in adults with moderate-to-severe AD. Exposure-adjusted analyses assessed infection rates. Results: Of 2932 patients, 1091 received placebo, 1095 dupilumab 300 mg weekly, and 746 dupilumab 300 mg every 2 weeks. Treatment groups had similar infection rates overall per 100 patient-years (placebo, 155; dupilumab weekly, 150; dupilumab every 2 weeks, 156; dupilumab combined, 152), and similar non-skin infection rates. Serious/severe infections were reduced with dupilumab (risk ratio 0.43; p < 0.05), as were bacterial and other non-herpetic skin infections (risk ratio 0.44; p < 0.001). Although herpesviral infection rates overall were slightly higher with dupilumab than placebo, clinically important herpesviral infections (eczema herpeticum, herpes zoster) were less common with dupilumab (risk ratio 0.31; p < 0.01). Systemic anti-infective medication use was lower with dupilumab. Conclusions: Dupilumab is associated with reduced risk of serious/severe infections and non-herpetic skin infections and does not increase overall infection rates versus placebo in patients with moderate-to-severe AD. ClinicalTrials.gov Identifiers: NCT01548404, NCT02210780, NCT01859988, NCT02277743, NCT02277769, NCT02260986, and NCT02755649
Is the Sun Embedded in a Typical Interstellar Cloud?
The physical properties and kinematics of the partially ionized interstellar
material near the Sun are typical of warm diffuse clouds in the solar vicinity.
The interstellar magnetic field at the heliosphere and the kinematics of nearby
clouds are naturally explained in terms of the S1 superbubble shell. The
interstellar radiation field at the Sun appears to be harder than the field
ionizing ambient diffuse gas, which may be a consequence of the low opacity of
the tiny cloud surrounding the heliosphere. The spatial context of the Local
Bubble is consistent with our location in the Orion spur.Comment: "From the Outer Heliosphere to the Local Bubble", held at
International Space Sciences Institute, October 200
Interpersonal effects of parents and adolescents on each other’s health behaviours: a dyadic extension of the theory of planned behaviour
Objective: Interpersonal relationships are important predictors of health outcomes and interpersonal influences on behaviours may be key mechanisms underlying such effects. Most health behaviour theories focus on intrapersonal factors and may not adequately account for interpersonal influences. We evaluate a dyadic extension of the Theory of Planned Behaviour by examining whether parent and adolescent characteristics (attitudes, subjective norms, perceived behavioural control and intentions) are associated with not only their own but also each other’s intentions/behaviours.
Design: Using the Actor-Partner Interdependence Model, we analyse responses from 1717 parent-adolescent dyads from the Family Life, Activity, Sun, Health, and Eating study.
Main Outcome Measures: Adolescents/parents completed self-reports of their fruit and vegetable consumption, junk food and sugary drinks consumption, engagement in physical activity, and engagement in screen time sedentary behaviours.
Results: Parent/adolescent characteristics are associated with each other’s health-relevant intentions/behaviours above the effects of individuals’ own characteristics on their own behaviours. Parent/adolescent characteristics covary with each other’s outcomes with similar strength, but parent characteristics more strongly relate to adolescent intentions, whereas adolescent characteristics more strongly relate to parent behaviours.
Conclusions: Parents and adolescents may bidirectionally influence each other’s health intentions/behaviours. This highlights the importance of dyadic models of health behaviour and suggests intervention targets
Two Phase 3 Trials of Dupilumab versus Placebo in Atopic Dermatitis.
BACKGROUND
Dupilumab, a human monoclonal antibody against interleukin-4 receptor alpha, inhibits
signaling of interleukin-4 and interleukin-13, type 2 cytokines that may be important
drivers of atopic or allergic diseases such as atopic dermatitis.
METHODS
In two randomized, placebo-controlled, phase 3 trials of identical design (SOLO 1
and SOLO 2), we enrolled adults with moderate-to-severe atopic dermatitis whose
disease was inadequately controlled by topical treatment. Patients were randomly
assigned in a 1:1:1 ratio to receive, for 16 weeks, subcutaneous dupilumab (300 mg)
or placebo weekly or the same dose of dupilumab every other week alternating
with placebo. The primary outcome was the proportion of patients who had both
a score of 0 or 1 (clear or almost clear) on the Investigator’s Global Assessment
and a reduction of 2 points or more in that score from baseline at week 16.
RESULTS
We enrolled 671 patients in SOLO 1 and 708 in SOLO 2. In SOLO 1, the primary
outcome occurred in 85 patients (38%) who received dupilumab every other week and
in 83 (37%) who received dupilumab weekly, as compared with 23 (10%) who received
placebo (P<0.001 for both comparisons with placebo). The results were similar in
SOLO 2, with the primary outcome occurring in 84 patients (36%) who received dupilumab
every other week and in 87 (36%) who received dupilumab weekly, as compared
with 20 (8%) who received placebo (P<0.001 for both comparisons). In addition,
in the two trials, an improvement from baseline to week 16 of at least 75% on the
Eczema Area and Severity Index was reported in significantly more patients who received
each regimen of dupilumab than in patients who received placebo (P<0.001 for
all comparisons). Dupilumab was also associated with improvement in other clinical
end points, including reduction in pruritus and symptoms of anxiety or depression
and improvement in quality of life. Injection-site reactions and conjunctivitis were
more frequent in the dupilumab groups than in the placebo groups.
CONCLUSIONS
In two phase 3 trials of identical design involving patients with atopic dermatitis,
dupilumab improved the signs and symptoms of atopic dermatitis, including
pruritus, symptoms of anxiety and depression, and quality of life, as compared
with placebo. Trials of longer duration are needed to assess the long-term effectiveness
and safety of dupilumab. (Funded by Sanofi and Regeneron Pharmaceuticals;
SOLO 1 ClinicalTrials.gov number, NCT02277743; SOLO 2 ClinicalTrials
.gov number, NCT02277769.
High-throughput imaging assay for drug screening of 3D prostate cancer organoids
First Published June 11, 2021New treatments are required for advanced prostate cancer; however, there are fewer preclinical models of prostate cancer than other common tumor types to test candidate therapeutics. One opportunity to increase the scope of preclinical studies is to grow tissue from patient-derived xenografts (PDXs) as organoid cultures. Here we report a scalable pipeline for automated seeding, treatment and an analysis of the drug responses of prostate cancer organoids. We established organoid cultures from 5 PDXs with diverse phenotypes of prostate cancer, including castrate-sensitive and castrate-resistant disease, as well as adenocarcinoma and neuroendocrine pathology. We robotically embedded organoids in Matrigel in 384-well plates and monitored growth via brightfield microscopy before treatment with poly ADP-ribose polymerase inhibitors or a compound library. Independent readouts including metabolic activity and live-cell imaging-based features provided robust measures of organoid growth and complementary ways of assessing drug efficacy. Single organoid analyses enabled in-depth assessment of morphological differences between patients and within organoid populations and revealed that larger organoids had more striking changes in morphology and composition after drug treatment. By increasing the scale and scope of organoid experiments, this automated assay complements other patient-derived models and will expedite preclinical testing of new treatments for prostate cancer.Nicholas Choo, Susanne Ramm, Jennii Luu, Jean M. Winter, Luke A. Selth, Amy R. Dwyer … et al
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