647 research outputs found
From START to FINISH : the influence of osmotic stress on the cell cycle
Peer reviewedPublisher PD
Effect of Tumor-Treating Fields Plus Maintenance Temozolomide vs Maintenance Temozolomide Alone on Survival in Patients With Glioblastoma: A Randomized Clinical Trial.
Tumor-treating fields (TTFields) is an antimitotic treatment modality that interferes with glioblastoma cell division and organelle assembly by delivering low-intensity alternating electric fields to the tumor.
To investigate whether TTFields improves progression-free and overall survival of patients with glioblastoma, a fatal disease that commonly recurs at the initial tumor site or in the central nervous system.
In this randomized, open-label trial, 695 patients with glioblastoma whose tumor was resected or biopsied and had completed concomitant radiochemotherapy (median time from diagnosis to randomization, 3.8 months) were enrolled at 83 centers (July 2009-2014) and followed up through December 2016. A preliminary report from this trial was published in 2015; this report describes the final analysis.
Patients were randomized 2:1 to TTFields plus maintenance temozolomide chemotherapy (n = 466) or temozolomide alone (n = 229). The TTFields, consisting of low-intensity, 200 kHz frequency, alternating electric fields, was delivered (≥ 18 hours/d) via 4 transducer arrays on the shaved scalp and connected to a portable device. Temozolomide was administered to both groups (150-200 mg/m2) for 5 days per 28-day cycle (6-12 cycles).
Progression-free survival (tested at α = .046). The secondary end point was overall survival (tested hierarchically at α = .048). Analyses were performed for the intent-to-treat population. Adverse events were compared by group.
Of the 695 randomized patients (median age, 56 years; IQR, 48-63; 473 men [68%]), 637 (92%) completed the trial. Median progression-free survival from randomization was 6.7 months in the TTFields-temozolomide group and 4.0 months in the temozolomide-alone group (HR, 0.63; 95% CI, 0.52-0.76; P < .001). Median overall survival was 20.9 months in the TTFields-temozolomide group vs 16.0 months in the temozolomide-alone group (HR, 0.63; 95% CI, 0.53-0.76; P < .001). Systemic adverse event frequency was 48% in the TTFields-temozolomide group and 44% in the temozolomide-alone group. Mild to moderate skin toxicity underneath the transducer arrays occurred in 52% of patients who received TTFields-temozolomide vs no patients who received temozolomide alone.
In the final analysis of this randomized clinical trial of patients with glioblastoma who had received standard radiochemotherapy, the addition of TTFields to maintenance temozolomide chemotherapy vs maintenance temozolomide alone, resulted in statistically significant improvement in progression-free survival and overall survival. These results are consistent with the previous interim analysis.
clinicaltrials.gov Identifier: NCT00916409
Does intra-party democracy affect levels of trust in parties?:the cases of Belgium and Israel
Previous research has shown a steady decline of citizen's political trus and growing skepticism towards key institutions of representative democr acy. Political parties, which perform the crucial role of linking citizens to the political system, are in the eye of the storm: citizens are generally more distrusting towards parties than other social and political institutions. The relevant literature mentions that parties often implement intra-party democratization to remedy party distrust. This article examines whether democratic candidate selection processes actually affect party trust among voters. The analysis is based on the cases of Belgium and Israel, where politicians made a strong case for intra-party democracy in recent history. The results indicate that, while inclusive selectorates indeed increase trust levels, decentralization decreases trust towards parties in both countries
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The UfM and the Middle East 'Peace Process': An Unhappy Symbiosis
This contribution explores differing theories on how the failure of the ‘peace process’ featured in the design and goals of the UfM, drawing on lessons from the period when the EMP was pursued in parallel with the peace process. In each case, institutional overlaps are identified, as well as commonalities in the approaches of the actors to both pursuits. Crucially, however, the persistence and intensification of the Arab–Israeli conflict, in combination with the shift from multilateralism to bilateralism embodied in the UfM, has politicized the latter at the expense of the functionalist aspirations of its architects
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Clades of huge phages from across Earth's ecosystems.
Bacteriophages typically have small genomes1 and depend on their bacterial hosts for replication2. Here we sequenced DNA from diverse ecosystems and found hundreds of phage genomes with lengths of more than 200 kilobases (kb), including a genome of 735 kb, which is-to our knowledge-the largest phage genome to be described to date. Thirty-five genomes were manually curated to completion (circular and no gaps). Expanded genetic repertoires include diverse and previously undescribed CRISPR-Cas systems, transfer RNAs (tRNAs), tRNA synthetases, tRNA-modification enzymes, translation-initiation and elongation factors, and ribosomal proteins. The CRISPR-Cas systems of phages have the capacity to silence host transcription factors and translational genes, potentially as part of a larger interaction network that intercepts translation to redirect biosynthesis to phage-encoded functions. In addition, some phages may repurpose bacterial CRISPR-Cas systems to eliminate competing phages. We phylogenetically define the major clades of huge phages from human and other animal microbiomes, as well as from oceans, lakes, sediments, soils and the built environment. We conclude that the large gene inventories of huge phages reflect a conserved biological strategy, and that the phages are distributed across a broad bacterial host range and across Earth's ecosystems
The S phase checkpoint promotes the Smc5/6 complex dependent SUMOylation of Pol2, the catalytic subunit of DNA polymerase ε
Replication fork stalling and accumulation of single-stranded DNA trigger the S phase checkpoint, a signalling cascade that, in budding yeast, leads to the activation of the Rad53 kinase. Rad53 is essential in maintaining cell viability, but its targets of regulation are still partially unknown. Here we show that Rad53 drives the hyper-SUMOylation of Pol2, the catalytic subunit of DNA polymerase ε, principally following replication forks stalling induced by nucleotide depletion. Pol2 is the main target of SUMOylation within the replisome and its modification requires the SUMO-ligase Mms21, a subunit of the Smc5/6 complex. Moreover, the Smc5/6 complex co-purifies with Pol ε, independently of other replisome components. Finally, we map Pol2 SUMOylation to a single site within the N-terminal catalytic domain and identify a SUMO-interacting motif at the C-terminus of Pol2. These data suggest that the S phase checkpoint regulate Pol ε during replication stress through Pol2 SUMOylation and SUMO-binding abilit
AUX1-mediated root hair auxin influx governs SCFTIR1/AFB-type Ca2+ signaling
Auxin is a key regulator of plant growth and development, but the causal relationship between hormone transport and root responses remains unresolved. Here we describe auxin uptake, together with early steps in signaling, in Arabidopsis root hairs. Using intracellular microelectrodes we show membrane depolarization, in response to IAA in a concentration- and pH-dependent manner. This depolarization is strongly impaired in aux1 mutants, indicating that AUX1 is the major transporter for auxin uptake in root hairs. Local intracellular auxin application triggers Ca2+ signals that propagate as long-distance waves between root cells and modulate their auxin responses. AUX1-mediated IAA transport, as well as IAA- triggered calcium signals, are blocked by treatment with the SCFTIR1/AFB - inhibitor auxinole. Further, they are strongly reduced in the tir1afb2afb3 and the cngc14 mutant. Our study reveals that the AUX1 transporter, the SCFTIR1/AFB receptor and the CNGC14 Ca2+ channel, mediate fast auxin signaling in roots
Bumble bee parasite strains vary in resistance to phytochemicals
Nectar and pollen contain diverse phytochemicals that can reduce disease in pollinators. However, prior studies showed variable effects of nectar chemicals on infection, which could reflect variable phytochemical resistance among parasite strains. Inter-strain variation in resistance could influence evolutionary interactions between plants, pollinators, and pollinator disease, but testing direct effects of phytochemicals on parasites requires elimination of variation between bees. Using cell cultures of the bumble bee parasite Crithidia bombi, we determined (1) growth-inhibiting effects of nine floral phytochemicals and (2) variation in phytochemical resistance among four parasite strains.
C. bombi growth was unaffected by naturally occurring concentrations of the known antitrypanosomal phenolics gallic acid, caffeic acid, and chlorogenic acid. However, C. bombi growth was inhibited by anabasine, eugenol, and thymol. Strains varied >3-fold in phytochemical resistance, suggesting that selection for phytochemical resistance could drive parasite evolution. Inhibitory concentrations of thymol (4.53-22.2 ppm) were similar to concentrations in Thymus vulgaris nectar (mean 5.2 ppm). Exposure of C. bombi to naturally occurring levels of phytochemicals—either within bees or during parasite transmission via flowers—could influence infection in nature. Flowers that produce antiparasitic phytochemical, including thymol, could potentially reduce infection in Bombus populations, thereby counteracting a possible contributor to pollinator decline
Is overseas volunteering beneficial to the NHS? The analysis of volunteers’ responses to a feedback questionnaire following experiences in low-income and middle-income countries
Introduction
Locally requested and planned overseas volunteering in low-income and middle-income countries by National Health Service (NHS) staff can have benefits for the host or receiving nation, but its impact on the professional development of NHS staff is not proven. The Knowledge and Skills Framework (KSF) and Leadership Framework (LF) are two tools used by employers as a measure of individuals' development. We have used dimensions from both tools as a method of evaluating the benefit to NHS doctors who volunteer overseas.
Methods
88 NHS volunteers participating with local colleagues in Primary Trauma Care and orthopaedic surgical training courses in sub-Saharan Africa were asked to complete an online self-assessment questionnaire 6 months following their return to the UK. The survey consisted of questions based on qualities outlined in both the KSF and LF.
Results
85 completed responses to the questionnaire were received. In every KSF domain assessed, the majority of volunteers agreed that their overseas volunteering experience improved their practice within the NHS. Self-assessed pre-course and post-course scores evaluating the LF also saw a universal increase, notably in the ‘working with others’ domain.
Discussion
There is a growing body of literature outlining the positive impact of overseas volunteering on NHS staff. Despite increasing evidence that such experiences can develop volunteers’ essential skills, individuals often find it difficult to gain support of their employers. Our study, in line with the current literature, shows that overseas volunteering by NHS staff can provide an opportunity to enhance professional and personal development. Skills gained from volunteering within international links match many of the qualities outlined in both KSF and LF, directly contributing to volunteers’ continued professional development
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