FRET-based dynamic structural biology: Challenges, perspectives and an appeal for open-science practices

Single-molecule FRET (smFRET) has become a mainstream technique for studying biomolecular structural dynamics. The rapid and wide adoption of smFRET experiments by an ever-increasing number of groups has generated significant progress in sample preparation, measurement procedures, data analysis, algorithms and documentation. Several labs that employ smFRET approaches have joined forces to inform the smFRET community about streamlining how to perform experiments and analyze results for obtaining quantitative information on biomolecular structure and dynamics. The recent efforts include blind tests to assess the accuracy and the precision of smFRET experiments among different labs using various procedures. These multi-lab studies have led to the development of smFRET procedures and documentation, which are important when submitting entries into the archiving system for integrative structure models, PDB-Dev. This position paper describes the current ‘state of the art’ from different perspectives, points to unresolved methodological issues for quantitative structural studies, provides a set of ‘soft recommendations’ about which an emerging consensus exists, and lists openly available resources for newcomers and seasoned practitioners. To make further progress, we strongly encourage ‘open science’ practices

Results of an early access treatment protocol of daratumumab monotherapy in spanish patients with relapsed or refractory multiple myeloma

Daratumumab is a human CD38-targeted monoclonal antibody approved as monotherapy for heavily pretreated relapsed and refractory multiple myeloma. We report findings for the Spanish cohort of an open-label treatment protocol that provided early access to daratumumab monotherapy and collected safety and patient-reported outcomes data for patients with relapsed or refractory multiple myeloma. At 15 centers across Spain, intravenous daratumumab (16mg/kg) was administered to 73 patients who had ≥3 prior lines of therapy, including a proteasome inhibitor and an immunomodulatory drug, or who were double refractory to both. The median duration of daratumumab treatment was 3.3 (range: 0.03–13.17) months, with a median number of 12 (range: 1–25) infusions. Grade 3/4 treatment-emergent adverse events were reported in 74% of patients and included lymphopenia (28.8%), thrombocytopenia (27.4%), neutropenia (21.9%), leukopenia (19.2%), and anemia (15.1%). Common (>5%) serious treatmentemergent adverse events included respiratory tract infection (9.6%), general physical health deterioration (6.8%), and back pain (5.5%). Infusion-related reactions occurred in 45% of patients. The median change from baseline in all domains of the EQ-5D-5L and EORTC QLQ-C30 was mostly 0. A total of 18 (24.7%) patients achieved a partial response or better, with 10 (13.7%) patients achieving a very good partial response or better. Median progression-free survival was 3.98 months. The results of this early access treatment protocol are consistent with previously reported trials of daratumumab monotherapy and confirm its safety and antitumoral efficacy in Spanish patients with heavily treated relapsed or refractory multiple myeloma

Labeled EF-Tus for rapid kinetic studies of pretranslocation complex formation

The universally conserved translation elongation factor EF-Tu delivers aminoacyl(aa)-tRNA in the form of an aa-tRNA·EF-Tu·GTP ternary complex (TC) to the ribosome where it binds to the cognate mRNA codon within the ribosomal A-site, leading to formation of a pretranslocation (PRE) complex. Here we describe preparation of QSY9 and Cy5 derivatives of the variant E348C-EF-Tu that are functional in translation elongation. Together with fluorophore derivatives of aa-tRNA and of ribosomal protein L11, located within the GTPase associated center (GAC), these labeled EF-Tus allow development of two new FRET assays that permit the dynamics of distance changes between EF-Tu and both L11 (Tu-L11 assay) and aa-tRNA (Tu-tRNA assay) to be determined during the decoding process. We use these assays to examine: (i) the relative rates of EF-Tu movement away from the GAC and from aa-tRNA during decoding, (ii) the effects of the misreading-inducing antibiotics streptomycin and paromomycin on tRNA selection at the A-site, and (iii) how strengthening the binding of aa-tRNA to EF-Tu affects the rate of EF-Tu movement away from L11 on the ribosome. These FRET assays have the potential to be adapted for high throughput screening of ribosomal antibiotics

Pain and delirium in people with dementia in the acute general hospital setting

YesBackground: Pain and delirium are common in people with dementia admitted to hospitals. These are often under-diagnosed and under-treated. Pain is implicated as a cause of delirium but this association has not been investigated in this setting. Objective: To investigate the relationship between pain and delirium in people with dementia, on admission and throughout a hospital admission. Design: Exploratory secondary analysis of observational prospective longitudinal cohort data. Setting: Two acute hospitals in the UK. Methodology: Two-hundred and thirty participants aged ≥70 years were assessed for dementia severity, delirium ((Confusion Assessment Method (CAM), pain (Pain Assessment in Advanced Dementia (PAINAD)) scale and prescription of analgesics. Logistic and linear regressions explored the relationship between pain and delirium using cross-sectional data. Results: Pain at rest developed in 49%, and pain during activity for 26% of participants during their inpatient stay. Incident delirium developed in 15%, of participants, and 42% remained delirious for at least two assessments. Of the 35% of participants who were delirious and unable to self-report pain, 33% of these participants experienced pain at rest, and 56 experienced pain during activity. The odds of being delirious were 3.26 times higher in participants experiencing pain at rest (95% Confidence Interval 1.03–10.25, P = 0.044). Conclusion: An association between pain at rest and delirium was found, suggesting pain may be a risk factor for delirium. Since pain and delirium were found to persist and develop during an inpatient stay, regular pain and delirium assessments are required to manage pain and delirium effectively.The Impact of Acute Hospitalisation on People with Dementia: The Behaviour and Pain (BepAID Study (jointly funded by the Alzheimer’s Society and BUPA foundation (Grant reference number: 131). Dr Sampson’s, Dr White’s, Dr Kupeli’s and Miss Vickerstaff ’s posts are supported by Marie Curie core funding, grant (MCCC-FCO-16-U)