76 research outputs found
A drug targeting only p110α can block phosphoinositide 3-kinase signalling and tumour growth in certain cell types
Genetic alterations in PI3K (phosphoinositide 3-kinase) signalling are common in cancer and include deletions in PTEN (phosphatase and tensin homologue deleted on chromosome 10), amplifications of PIK3CA and mutations in two distinct regions of the PIK3CA gene. This suggests drugs targeting PI3K, and p110α in particular, might be useful in treating cancers. Broad-spectrum inhibition of PI3K is effective in preventing growth factor signalling and tumour growth, but suitable inhibitors of p110α have not been available to study the effects of inhibiting this isoform alone. In the present study we characterize a novel small molecule, A66, showing the S-enantiomer to be a highly specific and selective p110α inhibitor. Using molecular modelling and biochemical studies, we explain the basis of this selectivity. Using a panel of isoform-selective inhibitors, we show that insulin signalling to Akt/PKB (protein kinase B) is attenuated by the additive effects of inhibiting p110α/p110β/p110δ in all cell lines tested. However, inhibition of p110α alone was sufficient to block insulin signalling to Akt/PKB in certain cell lines. The responsive cell lines all harboured H1047R mutations in PIK3CA and have high levels of p110α and class-Ia PI3K activity. This may explain the increased sensitivity of these cells to p110α inhibitors. We assessed the activation of Akt/PKB and tumour growth in xenograft models and found that tumours derived from two of the responsive cell lines were also responsive to A66 in vivo. These results show that inhibition of p110α alone has the potential to block growth factor signalling and reduce growth in a subset of tumours
The James Webb Space Telescope Mission
Twenty-six years ago a small committee report, building on earlier studies,
expounded a compelling and poetic vision for the future of astronomy, calling
for an infrared-optimized space telescope with an aperture of at least .
With the support of their governments in the US, Europe, and Canada, 20,000
people realized that vision as the James Webb Space Telescope. A
generation of astronomers will celebrate their accomplishments for the life of
the mission, potentially as long as 20 years, and beyond. This report and the
scientific discoveries that follow are extended thank-you notes to the 20,000
team members. The telescope is working perfectly, with much better image
quality than expected. In this and accompanying papers, we give a brief
history, describe the observatory, outline its objectives and current observing
program, and discuss the inventions and people who made it possible. We cite
detailed reports on the design and the measured performance on orbit.Comment: Accepted by PASP for the special issue on The James Webb Space
Telescope Overview, 29 pages, 4 figure
Primaquine for uncomplicated Plasmodium vivax malaria in children younger than 15 years: a systematic review and individual patient data meta-analysis.
BACKGROUND: Primaquine, the only widely available treatment to prevent relapsing Plasmodium vivax malaria, is produced as 15 mg tablets, and new paediatric formulations are being developed. To inform the optimal primaquine dosing regimen for children, we aimed to determine the efficacy and safety of different primaquine dose strategies in children younger than 15 years. METHODS: We undertook a systematic review (Jan 1, 2000-July 26, 2024) for P vivax efficacy studies with at least one treatment group that was administered primaquine over multiple days, that enrolled children younger than 15 years, that followed up patients for at least 28 days, and that had data available for inclusion by June 30, 2022. Patients were excluded if they were aged 15 years or older, presented with severe malaria, received adjunctive antimalarials within 14 days of diagnosis, commenced primaquine more than 7 days after starting schizontocidal treatment, had a protocol violation in the original study, or were missing data on age, sex, or primaquine dose. Available individual patient data were collated and standardised. To evaluate efficacy, the risk of recurrent P vivax parasitaemia between days 7 and 180 was assessed by time-to-event analysis for different total mg/kg primaquine doses (low total dose of ∼3·5 mg/kg and high total dose of ∼7 mg/kg). To evaluate tolerability and safety, the following were assessed by daily mg/kg primaquine dose (low daily dose of ∼0·25 mg/kg, intermediate daily dose of ∼0·5 mg/kg, and high daily dose of ∼1 mg/kg): gastrointestinal symptoms (vomiting, anorexia, or diarrhoea) on days 5-7, haemoglobin decrease of at least 25% to less than 7g/dL (severe haemolysis), absolute change in haemoglobin from day 0 to days 2-3 or days 5-7, and any serious adverse events within 28 days. This study is registered with PROSPERO, CRD42021278085. FINDINGS: In total, 3514 children from 27 studies and 15 countries were included. The cumulative incidence of recurrence by day 180 was 51·4% (95% CI 47·0-55·9) following treatment without primaquine, 16·0% (12·4-20·3) following a low total dose of primaquine, and 10·2% (8·4-12·3) following a high total dose of primaquine. The hazard of recurrent P vivax parasitaemia in children younger than 15 years was reduced following primaquine at low total doses (adjusted hazard ratio [HR] 0·17, 95% CI 0·11-0·25) and high total doses (0·09, 0·07-0·12), compared with no primaquine. In 525 children younger than 5 years, the relative rates of recurrence were also reduced, with an adjusted HR of 0·33 (95% CI 0·18-0·59) for a low total dose and 0·13 (0·08-0·21) for a high total dose of primaquine compared with no primaquine. The rate of recurrence following a high total dose was reduced compared with a low dose in children younger than 15 years (adjusted HR 0·54, 95% CI 0·35-0·85) and children younger than 5 years (0·41, 0·21-0·78). Compared with no primaquine, children treated with any dose of primaquine had a greater risk of gastrointestinal symptoms on days 5-7 after adjustment for confounders, with adjusted risks of 3·9% (95% CI 0-8·6) in children not treated with primaquine, 9·2% (0-18·7) with a low daily dose of primaquine, 6·8% (1·7-12·0) with an intermediate daily dose of primaquine, and 9·6% (4·8-14·3) with a high daily dose of primaquine. In children with 30% or higher glucose-6-phosphate dehydrogenase (G6PD) activity, there were few episodes of severe haemolysis following no primaquine (0·4%, 95% CI 0·1-1·5), a low daily dose (0·0%, 0·0-1·6), an intermediate daily dose (0·5%, 0·1-1·4), or a high daily dose (0·7%, 0·2-1·9). Of 15 possibly drug-related serious adverse events in children, two occurred following a low, four following an intermediate, and nine following a high daily dose of primaquine. INTERPRETATION: A high total dose of primaquine was highly efficacious in reducing recurrent P vivax parasitaemia in children compared with a low dose, particularly in children younger than 5 years. In children treated with high and intermediate daily primaquine doses compared with low daily doses, there was no increase in gastrointestinal symptoms or haemolysis (in children with 30% or higher G6PD activity), but there were more serious adverse events. FUNDING: Medicines for Malaria Venture, Bill & Melinda Gates Foundation, and Australian National Health and Medical Research Council
Genomic epidemiology of SARS-CoV-2 in a UK university identifies dynamics of transmission
AbstractUnderstanding SARS-CoV-2 transmission in higher education settings is important to limit spread between students, and into at-risk populations. In this study, we sequenced 482 SARS-CoV-2 isolates from the University of Cambridge from 5 October to 6 December 2020. We perform a detailed phylogenetic comparison with 972 isolates from the surrounding community, complemented with epidemiological and contact tracing data, to determine transmission dynamics. We observe limited viral introductions into the university; the majority of student cases were linked to a single genetic cluster, likely following social gatherings at a venue outside the university. We identify considerable onward transmission associated with student accommodation and courses; this was effectively contained using local infection control measures and following a national lockdown. Transmission clusters were largely segregated within the university or the community. Our study highlights key determinants of SARS-CoV-2 transmission and effective interventions in a higher education setting that will inform public health policy during pandemics.</jats:p
31st Annual Meeting and Associated Programs of the Society for Immunotherapy of Cancer (SITC 2016) : part two
Background
The immunological escape of tumors represents one of the main ob- stacles to the treatment of malignancies. The blockade of PD-1 or CTLA-4 receptors represented a milestone in the history of immunotherapy. However, immune checkpoint inhibitors seem to be effective in specific cohorts of patients. It has been proposed that their efficacy relies on the presence of an immunological response. Thus, we hypothesized that disruption of the PD-L1/PD-1 axis would synergize with our oncolytic vaccine platform PeptiCRAd.
Methods
We used murine B16OVA in vivo tumor models and flow cytometry analysis to investigate the immunological background.
Results
First, we found that high-burden B16OVA tumors were refractory to combination immunotherapy. However, with a more aggressive schedule, tumors with a lower burden were more susceptible to the combination of PeptiCRAd and PD-L1 blockade. The therapy signifi- cantly increased the median survival of mice (Fig. 7). Interestingly, the reduced growth of contralaterally injected B16F10 cells sug- gested the presence of a long lasting immunological memory also against non-targeted antigens. Concerning the functional state of tumor infiltrating lymphocytes (TILs), we found that all the immune therapies would enhance the percentage of activated (PD-1pos TIM- 3neg) T lymphocytes and reduce the amount of exhausted (PD-1pos TIM-3pos) cells compared to placebo. As expected, we found that PeptiCRAd monotherapy could increase the number of antigen spe- cific CD8+ T cells compared to other treatments. However, only the combination with PD-L1 blockade could significantly increase the ra- tio between activated and exhausted pentamer positive cells (p= 0.0058), suggesting that by disrupting the PD-1/PD-L1 axis we could decrease the amount of dysfunctional antigen specific T cells. We ob- served that the anatomical location deeply influenced the state of CD4+ and CD8+ T lymphocytes. In fact, TIM-3 expression was in- creased by 2 fold on TILs compared to splenic and lymphoid T cells. In the CD8+ compartment, the expression of PD-1 on the surface seemed to be restricted to the tumor micro-environment, while CD4 + T cells had a high expression of PD-1 also in lymphoid organs. Interestingly, we found that the levels of PD-1 were significantly higher on CD8+ T cells than on CD4+ T cells into the tumor micro- environment (p < 0.0001).
Conclusions
In conclusion, we demonstrated that the efficacy of immune check- point inhibitors might be strongly enhanced by their combination with cancer vaccines. PeptiCRAd was able to increase the number of antigen-specific T cells and PD-L1 blockade prevented their exhaus- tion, resulting in long-lasting immunological memory and increased median survival
Medievalism in the Modern World: Essays in Honour of Leslie J. Workman
This interdisciplinary collection of essays from leading scholars in Europe, North America, and Australia examine the phenomenon of medievalism from the perspective of history, politics, scholarship, art, and literature.
The twenty-six essays in this volume examine the process of creating the Middle Ages. In doing so, they honour Leslie Workman, who has led the revival of the study of medievalism in the past two generations, and leads this sub-discipline towards the comprehensiveness that Lord Acton as early as 1859 had promised: ´Two great principles divide the world, and contend for the mastery: antiquity and the Middle Ages. These are the two civilizations that have preceded us, the two elements of which ours is composed. All political as well as religious questions reduce themselves practically to this. This is the great dualism that runs through our society.` While using different approaches and discussing topics in a variety of specialised fields, the contributions clearly centre on negotiating the reception of medieval culture in the Early Modern, Modern and Contemporary periods, thus presenting a broad and representative picture of current research in medievalism.--From the publisher.https://scholarworks.uni.edu/facbook/1359/thumbnail.jp
Medievalism and the Academy, I
Edited book. Medievalism, the continuing process of creating the middle ages , engenders formal medieval studies from a wide variety of popular interests in the middle ages. This volume accordingly explores the common ground between artistic and popular constructions of the middle ages and the study of the middle ages within the academy. Essays treat the genesis of medieval studies in early modern antiquarianism; the erection of academic medievalism through persistent, indeed perverse, appeals to heroic medieval manliness and attenuated female spirituality; the current jeopardy of the book (a medieval invention) in the face of technological assault; the politics of the nineteenth-century academy (F.W. Furnival and others); the editorial practice of Sidney Lanier; and the cultural canonization of Chaucer. [Amazon.com]https://digitalcommons.odu.edu/english_books/1015/thumbnail.jp
High-quality chromosome-scale assembly of the walnut (Juglans regia L.) reference genome
The release of the first reference genome of walnut (Juglans regia L.) enabled many achievements in the
characterization of walnut genetic and functional variation. However, it is highly fragmented, preventing the integration of
genetic, transcriptomic, and proteomic information to fully elucidate walnut biological processes. Findings: Here, we report
the new chromosome-scale assembly of the walnut reference genome (Chandler v2.0) obtained by combining Oxford
Nanopore long-read sequencing with chromosome conformation capture (Hi-C) technology. Relative to the previous
reference genome, the new assembly features an 84.4-fold increase in N50 size, with the 16 chromosomal pseudomolecules
assembled and representing 95% of its total length. Using full-length transcripts from single-molecule real-time sequencing,
we predicted 37,554 gene models, with a mean gene length higher than the previous gene annotations. Most of the new
protein-coding genes (90%) present both start and stop codons, which represents a significant improvement compared with
Chandler v1.0 (only 48%). We then tested the potential impact of the new chromosome-level genome on different areas of
walnut research. By studying the proteome changes occurring during male flower development, we observed that the
virtual proteome obtained from Chandler v2.0 presents fewer artifacts than the previous reference genome, enabling the
identification of a new potential pollen allergen in walnut. Also, the new chromosome-scale genome facilitates in-depth
studies of intraspecies genetic diversity by revealing previously undetected autozygous regions in Chandler, likely resulting
from inbreeding, and 195 genomic regions highly differentiated between Western and Eastern walnut cultivars. Conclusion:
Overall, Chandler v2.0 will serve as a valuable resource to better understand and explore walnut biology
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