1,655 research outputs found
Repurposing screen identifies mebendazole as a clinical candidate to synergise with docetaxel for prostate cancer treatment
BACKGROUND: Docetaxel chemotherapy in prostate cancer has a modest impact on survival. To date, efforts to develop
combination therapies have not translated into new treatments. We sought to develop a novel therapeutic strategy to tackle
chemoresistant prostate cancer by enhancing the efficacy of docetaxel.
METHODS: We performed a drug-repurposing screen by using murine-derived prostate cancer cell lines driven by clinically
relevant genotypes. Cells were treated with docetaxel alone, or in combination with drugs (n = 857) from repurposing libraries, with
cytotoxicity quantified using High Content Imaging Analysis.
RESULTS: Mebendazole (an anthelmintic drug that inhibits microtubule assembly) was selected as the lead drug and shown to
potently synergise docetaxel-mediated cell killing in vitro and in vivo. Dual targeting of the microtubule structure was associated
with increased G2/M mitotic block and enhanced cell death. Strikingly, following combined docetaxel and mebendazole treatment,
no cells divided correctly, forming multipolar spindles that resulted in aneuploid daughter cells. Liposomes entrapping docetaxel
and mebendazole suppressed in vivo prostate tumour growth and extended progression-free survival.
CONCLUSIONS: Docetaxel and mebendazole target distinct aspects of the microtubule dynamics, leading to increased apoptosis
and reduced tumour growth. Our data support a new concept of combined mebendazole/docetaxel treatment that warrants
further clinical evaluation
The Acceptability and Usability of Digital Health Interventions for Adults With Depression, Anxiety, and Somatoform Disorders: Qualitative Systematic Review and Meta-Synthesis
The prevalence of mental health disorders continues to rise, with almost 4% of the world population having an anxiety disorder and almost 3.5% having depression in 2017. Despite the high prevalence, only one-third of people with depression or anxiety receive treatment. Over the last decade, the use of digital health interventions (DHIs) has risen rapidly as a means of accessing mental health care and continues to increase. Although there is evidence supporting the effectiveness of DHIs for the treatment of mental health conditions, little is known about what aspects are valued by users and how they might be improved. This systematic review aimed to identify, appraise, and synthesize the qualitative literature available on service users' views and experiences regarding the acceptability and usability of DHIs for depression, anxiety, and somatoform disorders. A systematic search strategy was developed, and searches were run in 7 electronic databases. Qualitative and mixed methods studies published in English were included. A meta-synthesis was used to interpret and synthesize the findings from the included studies. A total of 24 studies were included in the meta-synthesis, and 3 key themes emerged with descriptive subthemes. The 3 key themes were initial motivations and approaches to DHIs, personalization of treatment, and the value of receiving personal support in DHIs. The meta-synthesis suggests that participants' initial beliefs about DHIs can have an important effect on their engagement with these types of interventions. Personal support was valued very highly as a major component of the success of DHIs. The main reason for this was the way it enabled individual personalization of care. Findings from the systematic review have implications for the design of future DHIs to improve uptake, retention, and outcomes in DHIs for depression, anxiety, and somatoform disorders. DHIs need to be personalized to the specific needs of the individual. Future research should explore whether the findings could be generalized to other health conditions. [Abstract copyright: ©Shireen Patel, Athfah Akhtar, Sam Malins, Nicola Wright, Emma Rowley, Emma Young, Stephanie Sampson, Richard Morriss. Originally published in the Journal of Medical Internet Research (http://www.jmir.org), 06.07.2020.
Collateral ligament injuries of the metacarpophalangeal joint of the thumb: a treatment algorithm
The management of injury to the ulnar and radial collateral ligaments at the metacarpophalangeal joint of the thumb is complex. Treatment is dependent upon a number of factors with a wide variety of options for each ligament. Inadequate treatment has the potential to lead to a poor functional outcome. We present the relevant clinical anatomy, mechanism of injury, methods of treatment available and suggest a single treatment algorithm for use in the management of these injuries
Tracking TCRß sequence clonotype expansions during antiviral therapy using high-throughput sequencing of the hypervariable region
To maintain a persistent infection viruses such as hepatitis C virus (HCV) employ a range of mechanisms that subvert protective T cell responses. The suppression of antigen-specific T cell responses by HCV hinders efforts to profile T cell responses during chronic infection and antiviral therapy. Conventional methods of detecting antigen-specific T cells utilize either antigen stimulation (e.g., ELISpot, proliferation assays, cytokine production) or antigen-loaded tetramer staining. This limits the ability to profile T cell responses during chronic infection due to suppressed effector function and the requirement for prior knowledge of antigenic viral peptide sequences. Recently, high-throughput sequencing (HTS) technologies have been developed for the analysis of T cell repertoires. In the present study, we have assessed the feasibility of HTS of the TCRβ complementarity determining region (CDR)3 to track T cell expansions in an antigen-independent manner. Using sequential blood samples from HCV-infected individuals undergoing antiviral therapy, we were able to measure the population frequencies of >35,000 TCRβ sequence clonotypes in each individual over the course of 12 weeks. TRBV/TRBJ gene segment usage varied markedly between individuals but remained relatively constant within individuals across the course of therapy. Despite this stable TRBV/TRBJ gene segment usage, a number of TCRβ sequence clonotypes showed dramatic changes in read frequency. These changes could not be linked to therapy outcomes in the present study; however, the TCRβ CDR3 sequences with the largest fold changes did include sequences with identical TRBV/TRBJ gene segment usage and high junction region homology to previously published CDR3 sequences from HCV-specific T cells targeting the HLA-B*0801-restricted 1395HSKKKCDEL1403 and HLA-A*0101-restricted 1435ATDALMTGY1443 epitopes. The pipeline developed in this proof of concept study provides a platform for the design of future experiments to accurately address the question of whether T cell responses contribute to SVR upon antiviral therapy. This pipeline represents a novel technique to analyze T cell dynamics in situations where conventional antigen-dependent methods are limited due to suppression of T cell functions and highly diverse antigenic sequences
Thy-1 interaction with Fas in lipid rafts regulates fibroblast apoptosis and lung injury resolution.
Thy-1-negative lung fibroblasts are resistant to apoptosis. The mechanisms governing this process and its relevance to fibrotic remodeling remain poorly understood. By using either sorted or transfected lung fibroblasts, we found that Thy-1 expression is associated with downregulation of anti-apoptotic molecules Bcl-2 and Bcl-xL, as well as increased levels of cleaved caspase-9. Addition of rhFasL and staurosporine, well-known apoptosis inducers, caused significantly increased cleaved caspase-3, -8, and PARP in Thy-1-transfected cells. Furthermore, rhFasL induced Fas translocation into lipid rafts and its colocalization with Thy-1. These in vitro results indicate that Thy-1, in a manner dependent upon its glycophosphatidylinositol anchor and lipid raft localization, regulates apoptosis in lung fibroblasts via Fas-, Bcl-, and caspase-dependent pathways. In vivo, Thy-1 deficient (Thy1-/-) mice displayed persistence of myofibroblasts in the resolution phase of bleomycin-induced fibrosis, associated with accumulation of collagen and failure of lung fibrosis resolution. Apoptosis of myofibroblasts is decreased in Thy1-/- mice in the resolution phase. Collectively, these findings provide new evidence regarding the role and mechanisms of Thy-1 in initiating myofibroblast apoptosis that heralds the termination of the reparative response to bleomycin-induced lung injury. Understanding the mechanisms regulating fibroblast survival/apoptosis should lead to novel therapeutic interventions for lung fibrosis
Rewriting Nature’s Assembly Manual for a ssRNA Virus
Satellite Tobacco Necrosis Virus (STNV) is one of the smallest viruses known. Its genome encodes only its coat protein (CP) subunit relying on the polymerase of its helper virus TNV for replication. The genome contains a cryptic set of dispersed assembly signals in the form of stem-loops that each present a minimal CP binding motif -A.X.X.A- in the loops. The genomic fragment encompassing nucleotides 1-127 is predicted to contain five such Packaging Signals (PSs). We have used mutagenesis to determine the critical assembly features in this region. These include the CP binding motif, the relative placement of PS stem-loops, their number and their folding propensity. CP binding has an electrostatic contribution but assembly nucleation is dominated by the recognition of the folded PSs in the RNA fragment. Mutation to remove all –A.X.X.A- motifs in PSs throughout the genome yields an RNA that is unable to assemble efficiently. In contrast, when a synthetic 127nt fragment encompassing improved PSs is swapped onto the RNA otherwise lacking CP recognition motifs assembly is partially restored although the virus-like particles created are incomplete, implying that PSs outside this region are required for correct assembly. Swapping this improved region into the wild-type STNV1 sequence results in a better assembly substrate than the viral RNA, producing complete capsids and outcompeting the wild-type genome in head-to-head competition. These data confirm details of the PS-mediated assembly mechanism for STNV, and identify an efficient approach for production of stable viruslike particles encapsidating non-native RNAs or other cargoes
Understanding Robustness and Generalization of Artificial Neural Networks Through Fourier Masks
Despite the enormous success of artificial neural networks (ANNs) in many disciplines, the characterization of their computations and the origin of key properties such as generalization and robustness remain open questions. Recent literature suggests that robust networks with good generalization properties tend to be biased toward processing low frequencies in images. To explore the frequency bias hypothesis further, we develop an algorithm that allows us to learn modulatory masks highlighting the essential input frequencies needed for preserving a trained network's performance. We achieve this by imposing invariance in the loss with respect to such modulations in the input frequencies. We first use our method to test the low-frequency preference hypothesis of adversarially trained or data-augmented networks. Our results suggest that adversarially robust networks indeed exhibit a low-frequency bias but we find this bias is also dependent on directions in frequency space. However, this is not necessarily true for other types of data augmentation. Our results also indicate that the essential frequencies in question are effectively the ones used to achieve generalization in the first place. Surprisingly, images seen through these modulatory masks are not recognizable and resemble texture-like patterns
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