Fatigue among anaesthesiologists in Europe: Findings from a joint EBA/NASC survey.

BACKGROUND: Anaesthesiologists deliver an increasing amount of patient care and often work long hours in operating theatres and intensive care units, with frequent on-calls and insufficient rest in between. In the long term, this will negatively influence mental and physical health and well being. As fatigue becomes more prevalent, this has predictable implications for patient safety and clinical effectiveness. 1. OBJECTIVE: This study aimed to evaluate the prevalence, severity, causes and implications of work-related fatigue amongst specialist anaesthesiologists. DESIGN: An online survey of specialist anaesthesiologists. PARTICIPANTS: The survey was sent to anaesthesiologists in 42 European countries by electronic mail. MAIN OUTCOME MEASURES: Responses from a 36-item online survey assessed work-related fatigue and its impact on anaesthesiologists in European countries. RESULTS: Work-related fatigue was experienced in 91.6% of the 1508 respondents from 32 European countries. Fatigue was caused by their working patterns, clinical and nonclinical workloads, staffing issues and excessive work hours. Over 70% reported that work-related fatigue negatively impacted on their physical and mental health, emotional well being and safe commuting. Most respondents did not feel supported by their organisation to maintain good health and well being. CONCLUSION: Work-related fatigue is a significant and widespread problem amongst anaesthesiologists. More education and increased awareness of fatigue and its adverse effects on patient safety, staff well being and physical and mental health are needed. Departments should ensure that their rotas and job plans comply with the European Working Time Directive (EWTD) and introduce a fatigue risk management system to mitigate the effects of fatigue.

Fatigue amongst anaesthesiology and intensive care trainees in Europe: A matter of concern.

BACKGROUND: There is a growing awareness of the effects of fatigue on trainee wellbeing and health. Trainees in anaesthesiology and intensive care work long hours, switching work schedules frequently with insufficient rest. This may have unwanted long-term effects on mental and physical health and emotional well being, resulting in burnout and affecting patient safety. OBJECTIVE: The study aimed to evaluate the prevalence, severity, causes and effects of work-related fatigue in trainees in anaesthesiology and intensive care. DESIGN: Online survey of trainees in anaesthesiology and intensive care. SETTINGS: A total of 31 countries within Europe were included in the survey. PARTICIPANTS: European anaesthesiology and intensive care trainees who responded to an invitation to take part by electronic mail or through social media. MAIN OUTCOME MEASURES: Responses from a 29-item online survey to assess the realities within European countries with regards to work-related fatigue. RESULTS: One thousand and two hundred trainees from 31 European countries answered the survey demonstrating that an alarming number of trainees were fatigued by their working patterns and night shifts. Trainees reported effects on personal well being, safe commuting and potential for clinical errors. Respondents described a lack of support from hospitals and management for recovery during and after night shifts. CONCLUSION: Fatigue among trainees in anaesthesiology and intensive care has a significant impact on their well being and potentially, on the incidence of clinical errors. Current measures from authorities and hospital management are not sufficient to prevent serious fatigue, and therefore a fatigue risk management system should be considered. Failure to address this issue might lead to a further decline in trainees' wellbeing, their capacity to work in the speciality in the future, and potentially increase patient care errors.

Yarrowia lipolytica as a Platform for Punicic Acid Production.

Punicic acid (PuA) is a polyunsaturated fatty acid with significant medical, biological, and nutraceutical properties. The primary source of punicic acid is the pomegranate seed oil obtained from fruits of trees that are mainly cultivated in subtropical and tropical climates. To establish sustainable production of PuA, various recombinant microorganisms and plants have been explored as platforms with limited efficiencies. In this study, the oleaginous yeast Yarrowia lipolytica was employed as a host for PuA production. First, growth and lipid accumulation of Y. lipolytica were evaluated in medium supplemented with pomegranate seed oil, resulting in the accumulation of lipids up to 31.2%, consisting of 22% PuA esterified in the fraction of glycerolipids. In addition, lipid-engineered Y. lipolytica strains, transformed with the bifunctional fatty acid conjugase/desaturase from Punica granatum (PgFADX), showed the ability to accumulate PuA de novo. PuA was detected in both polar and neutral lipid fractions, especially in phosphatidylcholine and triacylglycerols. Promoter optimization for PgFADX expression resulted in improved accumulation of PuA from 0.9 to 1.8 mg/g of dry cell weight. The best-producing strain expressing PgFADX under the control of a strong erythritol-inducible promoter produced 36.6 mg/L PuA. These results demonstrate that the yeast Y. lipolytica is a promising host for PuA production.

Clinical characteristics and factors associated with ICU mortality during the first year of the SARS-Cov-2 pandemic in Romania: A prospective, cohort, multicentre study of 9000 patients.

BACKGROUND: The epidemiology of critically ill patients with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) may be different worldwide. Despite similarities in medicine quality and formation, there are also significant differences concerning healthcare and ICU organisation, staffing, financial resources and population compliance and adherence. Large cohort data of critically ill patients from Central and Eastern Europe are also lacking. OBJECTIVES: The study objectives were to describe the clinical characteristics of patients admitted to Romanian ICUs with SARS-CoV-2 infection and to identify the factors associated with ICU mortality. DESIGN: Prospective, cohort, observational study. SETTING: National recruitment, multicentre study, between March 2020 to March 2021. PATIENTS: All patients with SARS-CoV-2 infection admitted to Romanian ICUs were eligible. There were no exclusion criteria. INTERVENTION: None. MAIN OUTCOME MEASURE: ICU mortality. RESULTS: The statistical analysis included 9058 patients with definitive ICU outcome. The multivariable mixed effects logistic regression model found that age [odds ratio (OR) 1.27; 95% confidence interval (CI), 1.23 to 1.31], male gender (OR 1.21; 95% CI 1.05 to 1.4), medical history of neoplasia (OR 1.74; 95% CI, 1.36 to 2.22), chronic kidney disease (OR 1.54; 95% CI, 1.27 to 1.88), type II diabetes (OR 1.23; 95% CI, 1.06 to 1.43), chronic heart failure (OR 1.24; 95% CI, 1.03 to 1.49), dyspnoea (OR 1.3; 95% CI, 1.1 to 1.5), SpO2 less than 90% (OR 3; 95% CI, 2.5 to 3.5), admission SOFA score (OR 1.07; 95% CI, 1.05 to 1.09), acute respiratory distress syndrome (ARDS) on ICU admission (OR 1.35; 95% CI, 1.1 to 1.63) and the need for noninvasive (OR 1.8, 95% CI, 1.5 to 1.22) or invasive ventilation (OR 28; 95% CI, 22 to 35) and neuromuscular blockade (OR 3.5; 95% CI, 2.6 to 4.8), were associated with larger ICU mortality.Higher GCS on admission (OR 0.81; 95% CI, 0.79 to 0.83), treatment with hydroxychloroquine (OR 0.78; 95% CI, 0.64 to 0.95) and tocilizumab (OR 0.58; 95% CI, 0.48 to 0.71) were inversely associated with ICU mortality. CONCLUSION: The SARS-CoV-2 critically ill Romanian patients share common personal and clinical characteristics with published European cohorts. Public health measures and vaccination campaign should focus on patients at risk.

Toehold switch based biosensors for sensing the highly trafficked rosewood Dalbergia maritima.

Nucleic acid sensing is a 3 decades old but still challenging area of application for different biological sub-domains, from pathogen detection to single cell transcriptomics analysis. The many applications of nucleic acid detection and identification are mostly carried out by PCR techniques, sequencing, and their derivatives used at large scale. However, these methods' limitations on speed, cost, complexity and specificity have motivated the development of innovative detection methods among which nucleic acid biosensing technologies seem promising. Toehold switches are a particular class of RNA sensing devices relying on a conformational switch of secondary structure induced by the pairing of the detected trigger RNA with a de novo designed synthetic sensing mRNA molecule. Here we describe a streamlined methodology enabling the development of such a sensor for the RNA-mediated detection of an endangered plant species in a cell-free reaction system. We applied this methodology to help identify the rosewood Dalbergia maritima, a highly trafficked wood, whose protection is limited by the capacity of the authorities to distinguish protected logs from other unprotected but related species. The streamlined pipeline presented in this work is a versatile framework enabling cheap and rapid development of new sensors for custom RNA detection.

Investigating Different Levels of Bimanual Interaction With a Novel Motor Learning Task: A Behavioural and Transcranial Alternating Current Stimulation Study.

Many tasks require the skilled interaction of both hands, such as eating with knife and fork or keyboard typing. However, our understanding of the behavioural and neurophysiological mechanisms underpinning bimanual motor learning is still sparse. Here, we aimed to address this by first characterising learning-related changes of different levels of bimanual interaction and second investigating how beta tACS modulates these learning-related changes. To explore early bimanual motor learning, we designed a novel bimanual motor learning task. In the task, a force grip device held in each hand (controlling x- and y-axis separately) was used to move a cursor along a path of streets at different angles (0°, 22.5°, 45°, 67.5°, and 90°). Each street corresponded to specific force ratios between hands, which resulted in different levels of hand interaction, i.e., unimanual (Uni, i.e., 0°, 90°), bimanual with equal force (Bi eq , 45°), and bimanual with unequal force (Bi uneq 22.5°, 67.5°). In experiment 1, 40 healthy participants performed the task for 45 min with a minimum of 100 trials. We found that the novel task induced improvements in movement time and error, with no trade-off between movement time and error, and with distinct patterns for the three levels of bimanual interaction. In experiment 2, we performed a between-subjects, double-blind study in 54 healthy participants to explore the effect of phase synchrony between both sensorimotor cortices using tACS at the individual's beta peak frequency. The individual's beta peak frequency was quantified using electroencephalography. 20 min of 2 mA peak-to-peak amplitude tACS was applied during task performance (40 min). Participants either received in-phase (0° phase shift), out-of-phase (90° phase shift), or sham (3 s of stimulation) tACS. We replicated the behavioural results of experiment 1, however, beta tACS did not modulate motor learning. Overall, the novel bimanual motor task allows to characterise bimanual motor learning with different levels of bimanual interaction. This should pave the way for future neuroimaging studies to further investigate the underlying mechanism of bimanual motor learning.

Twenty years of evolution and diversification of digitaria streak virus in Digitaria setigera.

Within the family Geminiviridae, the emergence of new species results from their high mutation and recombination rates. In this study, we report the variability and evolution of digitaria streak virus (DSV), a mastrevirus isolated in 1986 from the grass Digitaria setigera in an island of the Vanuatu archipelago. Viral DNA of DSV samples was amplified from D. setigera specimens, derived from the naturally infected original plant, which were propagated in different laboratories in France and Italy for more than 20 years. From the consensus sequences, the nucleotide substitution rate was estimated for the period between a sample and the original sequence published in 1987, as well as for the period between samples. In addition, the intra-host genetic complexity and diversity of 8 DSV populations with a total of 165 sequenced haplotypes was characterized. The evolutionary rate of DSV was estimated to be between 1.13 × 10-4 and 9.87 × 10-4 substitutions/site/year, within the ranges observed in other single-stranded DNA viruses and RNA viruses. Bioinformatic analyses revealed high variability and heterogeneity in DSV populations, which confirmed that mutant spectra are continuously generated and are organized as quasispecies. The analysis of polymorphisms revealed nucleotide substitution biases in viral genomes towards deamination and oxidation of single-stranded DNA. The differences in variability in each of the genomic regions reflected a dynamic and modular evolution in the mutant spectra that was not reflected in the consensus sequences. Strikingly, the most variable region of the DSV genome, encoding the movement protein, showed rapid fixation of the mutations in the consensus sequence and a concomitant dN/dS ratio of 6.130, which suggests strong positive selection in this region. Phylogenetic analyses revealed a possible divergence in three genetic lineages from the original Vanuatu DSV isolate.

Exploring Hyperoxia Effects in Cancer-From Perioperative Clinical Data to Potential Molecular Mechanisms.

Increased inspiratory oxygen concentration is constantly used during the perioperative period of cancer patients to prevent the potential development of hypoxemia and to provide an adequate oxygen transport to the organs, tissues and cells. Although the primary tumours are surgically removed, the effects of perioperative hyperoxia exposure on distal micro-metastases and on circulating cancer cells can potentially play a role in cancer progression or recurrence. In clinical trials, hyperoxia seems to increase the rate of postoperative complications and, by delaying postoperative recovery, it can alter the return to intended oncological treatment. The effects of supplemental oxygen on the long-term mortality of surgical cancer patients offer, at this point, conflicting results. In experimental studies, hyperoxia effects on cancer biology were explored following multiple pathways. In cancer cell cultures and animal models, hyperoxia increases the production of reactive oxygen species (ROS) and increases the oxidative stress. These can be followed by the induction of the expression of Brain-derived neurotrophic factor (BDNF) and other molecules involved in angiogenesis and by the promotion of various degrees of epithelial mesenchymal transition (EMT).

Sevoflurane Modulates AKT Isoforms in Triple Negative Breast Cancer Cells. An Experimental Study.

(1) Background: Triple negative breast cancer (TNBC) is a highly aggressive tumor, associated with high rates of early distant recurrence and short survival times, and treatment may require surgery, and thus anesthesia. The effects of anesthetic drugs on cancer progression are under scrutiny, but published data are controversial, and the involved mechanisms unclear. Anesthetic agents have been shown to modulate several molecular cascades, including PI3K/AKT/mTOR. AKT isoforms are frequently amplified in various malignant tumors and associated with malignant cell survival, proliferation and invasion. Their activation is often observed in human cancers and is associated with decreased survival rate. Certain anesthetics are known to affect hypoxia cell signaling mechanisms by upregulating hypoxia-inducible factors (HIFs). (2) Methods: MCF-10A and MDA-MB 231 cells were cultivated and CellTiter-Blue® Cell Viability assay, 2D and 3D matrigel assay, immunofluorescence assays and gene expressions assay were performed after exposure to different sevoflurane concentrations. (3) Results: Sevoflurane exposure of TNBC cells results in morphological and behavioral changes. Sevoflurane differently influences the AKT isoforms expression in a time-dependent manner, with an important early AKT3 upregulation. The most significant effects occur at 72 h after 2 mM sevoflurane treatment and consist in increased viability, proliferation and aggressiveness and increased vimentin and HIF expression. (4) Conclusions: Sevoflurane exposure during surgery may contribute to cancer recurrence via AKT3 induced epithelial-mesenchymal transition (EMT) and by all three AKT isoforms enhanced cancer cell survival and proliferation.

Recent advances in the role of excitation-inhibition balance in motor recovery post-stroke.

Stroke affects millions of people worldwide each year, and stroke survivors are often left with motor deficits. Current therapies to improve these functional deficits are limited, making it a priority to better understand the pathophysiology of stroke recovery and find novel adjuvant options. The excitation-inhibition balance undergoes significant changes post-stroke, and the inhibitory neurotransmitter γ-aminobutyric acid (GABA) appears to play an important role in stroke recovery. In this review, we summarise the most recent studies investigating GABAergic inhibition at different stages of stroke. We discuss the proposed role of GABA in counteracting glutamate-mediated excitotoxicity in hyperacute stroke as well as the evidence linking decreased GABAergic inhibition to increased neuronal plasticity in early stroke. Then, we discuss two types of interventions that aim to modulate the excitation-inhibition balance to improve functional outcomes in stroke survivors: non-invasive brain stimulation (NIBS) and pharmacological interventions. Finding the optimal NIBS administration or adjuvant pharmacological therapies would represent an important contribution to the currently scarce therapy options.

Indwelling Device-Associated Biofilms in Critically Ill Cancer Patients-Study Protocol.

Health care-associated infections are a leading cause of inpatient complications. Rapid pathogen detection/identification is a major challenge in sepsis management that highly influences the successful outcome. The current standard of microorganism identification relies on bacterial growth in culture, which has several limitations. Gene sequencing research has developed culture-independent techniques for microorganism identification, with the aim to improve etiological diagnosis and, therefore, to change sepsis outcome. A prospective, observational, non-interventional, single-center study was designed that assesses biofilm-associated pathogens in a specific subpopulation of septic critically ill cancer patients. Indwelling device samples will be collected in septic patients at the moment of the removal of the arterial catheter, central venous catheter, endotracheal tube and urinary catheter. Concomitantly, clinical data regarding 4 sites (nasal, pharyngeal, rectal and skin) of pathogen colonization at the time of hospital/intensive care admission will be collected. The present study aims to offer new insights into biofilm-associated infections and to evaluate the infection caused by catheter-specific and patient-specific biofilm-associated pathogens in association with the extent of colonization. The analysis relies on the two following detection/identification techniques: standard microbiological method and next generation sequencing (NGS). Retrospectively, the study will estimate the clinical value of the NGS-based detection and its virtual potential in changing patient management and outcome, notably in the subjects with missing sepsis source or lack of response to anti-infective treatment.

Intra-abdominal hypertension and hypoxic respiratory failure together predict adverse outcome - A sub-analysis of a prospective cohort.

PURPOSE: To assess whether the combination of intra-abdominal hypertension (IAH, intra-abdominal pressure ≥ 12 mmHg) and hypoxic respiratory failure (HRF, PaO2/FiO2 ratio < 300 mmHg) in patients receiving invasive ventilation is an independent risk factor for 90- and 28-day mortality as well as ICU- and ventilation-free days. METHODS: Mechanically ventilated patients who had blood gas analyses performed and intra-abdominal pressure measured, were included from a prospective cohort. Subgroups were defined by the absence (Group 1) or the presence of either IAH (Group 2) or HRF (Group 3) or both (Group 4). Mixed-effects regression analysis was performed. RESULTS: Ninety-day mortality increased from 16% (Group 1, n = 50) to 30% (Group 2, n = 20) and 27% (Group 3, n = 100) to 49% (Group 4, n = 142), log-rank test p < 0.001. The combination of IAH and HRF was associated with increased 90- and 28-day mortality as well as with fewer ICU- and ventilation-free days. The association with 90-day mortality was no longer present after adjustment for independent variables. However, the association with 28-day mortality, ICU- and ventilation-free days persisted after adjusting for independent variables. CONCLUSIONS: In our sub-analysis, the combination of IAH and HRF was not independently associated with 90-day mortality but independently increased the odds of 28-day mortality, and reduced the number of ICU- and ventilation-free days.

Analysis of emergency head computed tomography in critically ill oncological patients.

BACKGROUND: Critically ill cancer patients have an increased risk of developing acute neurological signs. The study objective was to evaluate the use and the usefulness of emergency head computed tomography (EHCT) in this category of patients. PATIENTS AND METHODS: This retrospective, single-centre, cohort study included patients with EHCT performed during Intensive Care Unit (ICU) admission for a period of three years. Indications, imagistic findings, type of malignancy, and outcome were evaluated to identify diagnostic yield and correlations between abnormal findings on positive scans, malignancy type, and mortality rate. RESULTS: Sixty-four EHCTs were performed in 54 critically ill cancer patients, with 32 scans (50%) showing previously unknown lesions and considered to be positive. The most frequent abnormal findings were ischemic (15 EHCTs, 47%) and haemorrhagic (13 EHCTs, 40%) lesions. Thirty-eight EHCTs (59%) were indicated for altered mental status, with a positivity rate of 50%. Eighteen EHCTs (48%) were performed in hematological malignancy patients: 9 (50%) of which were positive with 8/9 (89%) displaying hemorrhagic lesions. Twenty EHCTs were performed in solid tumour patients, 10 (50%) of which were positive, with 9/10 (90%) displaying ischemic lesions. Out of 54 patients, 30 (55%) died during ICU stay. The mortality rate was higher in patients with hematological malignancies and positive EHCT (78% vs. 58%). CONCLUSIONS: Diagnostic yield of EHCT in critically ill cancer patients is much higher than in other categories of ICU patients. We support the systematic use of EHCT in critically ill, mainly hemato-oncological patients with nonspecific neurological dysfunction, as it may lead to early identification of intracranial complications.

Preoperative Cognitive Impairment and the Prevalence of Postoperative Delirium in Elderly Cancer Patients-A Prospective Observational Study.

Preoperative cognitive impairment (PCI) in cancer patients includes a broad spectrum of neurocognitive changes produced by complex interplay of patient, tumoural and treatment-related factors. Reduced preoperative cognitive reserve can favour the emergence of postoperative delirium (POD). The study aims to document PCI prevalence and to assess the relationship with POD in elderly cancer patients. The prospective observational study included consecutive patients scheduled for elective surgery; PCI was assessed with Mini-Cog test and defined at a score ≤ 3, POD was screened using Nursing Delirium Screening Scale (Nu-DESC) and defined at a score ≥ 2. Data on education, American Society of Anesthesiologists (ASA) score, preoperative medications, substance use, comorbidities, sensorial deficits, surgery and anaesthesia type, anaesthetic drugs, Mini-Cog score, postoperative pain, Nu-DESC were collected. In total, 131 patients were enrolled, mean age 72.1 ± 5.9 years. PCI prevalence was 51.9% (n = 68). POD prevalence was 19.8% (n = 26), with significantly higher value in PCI patients (27.9% vs. 11.1%, p = 0.016). In multivariate analysis, Mini-Cog score ≤ 3 (OR = 2.6, p = 0.027), clock draw (OR: 2.9, p = 0.013), preoperative renal dysfunction (OR = 2.6, p = 0.012), morphine (OR = 2.7, p = 0.007), metoclopramide (OR = 6.6, p = 0.006), and high pain score (OR = 1.8, p = 0.018) had a significant association with POD development. In this sample of elderly patients, PCI had a high prevalence and predicted the emergence of POD. Incorporating Mini-Cog test into the preoperative evaluation of onco-geriatric patients seems valuable and feasible.

ICTV Virus Taxonomy Profile: Nanoviridae.

Nanoviridae is a family of plant viruses (nanovirids) whose members have small isometric virions and multipartite, circular, single-stranded (css) DNA genomes. Each of the six (genus Babuvirus) or eight (genus Nanovirus) genomic DNAs is 0.9-1.1 kb and is separately encapsidated. Many isolates are associated with satellite-like cssDNAs (alphasatellites) of 1.0-1.1 kb. Hosts are eudicots, predominantly legumes (genus Nanovirus), and monocotyledons, predominantly in the order Zingiberales (genus Babuvirus). Nanovirids require a virus-encoded helper factor for transmission by aphids in a circulative, non-propagative manner. This is a summary of the ICTV Report on the family Nanoviridae, which is available at ictv.global/report/nanoviridae.

TECHNICAL DIFFICULTIES AND PROCEDURAL COMPLICATIONS IN CLOSING MALIGNANT ESOPHAGEAL-RESPIRATORY FISTULAS.

The aim of the study was to outline technical difficulties and procedural complications of using partially covered esophageal self-expandable metal stents (SEMSs) in malignant esophageal respiratory fistulas (ERFs) as a palliative treatment option. In this study, 150 patients with malignant dysphagia underwent treatment with SEMSs. A total of 36 ERFs were detected through endoscopic or clinical assessment. Complete fistula sealing with SEMSs was possible in 35 of the 36 patients. The majority of fistulas were diagnosed in male patients with advanced esophageal cancer. All of them presented with prolonged dysphagia and cachexia. Stent migration or tumoral overgrowth was identified in 6 cases with recurrent dysphagia, and required a second stent insertion. SEMSs were highly efficient in 98% of the patients studied with ERFs, with successfully sealed ERFs after the first attempt, with an overall median survival rate of 92 days. The technique of esophageal SEMS placement is simple and can be rapidly mastered. Patients with ERFs have a respiratory shunt that makes intubation difficult and is often avoided. Restoring oral feeding increased the patient quality of life. SEMS placement is generally safe, but has few associated postoperative complications.

A single, clinically relevant dose of the GABAB agonist baclofen impairs visuomotor learning.

KEY POINTS: Baclofen is a GABAB agonist prescribed as a treatment for spasticity in stroke, brain injury and multiple sclerosis patients, who are often undergoing concurrent motor rehabilitation. Decreasing GABAergic inhibition is a key feature of motor learning and so there is a possibility that GABA agonist drugs, such as baclofen, could impair these processes, potentially impacting rehabilitation. Here, we examined the effect of 10 mg of baclofen, in 20 young healthy individuals, and found that the drug impaired retention of visuomotor learning with no significant effect on motor sequence learning. Overall baclofen did not alter transcranial magnetic stimulation-measured GABAB inhibition, although the change in GABAB inhibition correlated with aspects of visuomotor learning retention. Further work is needed to investigate whether taking baclofen impacts motor rehabilitation in patients. ABSTRACT: The GABAB agonist baclofen is taken daily as a treatment for spasticity by millions of stroke, brain injury and multiple sclerosis patients, many of whom are also undergoing motor rehabilitation. However, decreases in GABA are suggested to be a key feature of human motor learning, which raises questions about whether drugs increasing GABAergic activity may impair motor learning and rehabilitation. In this double-blind, placebo-controlled study, we investigated whether a single 10 mg dose of the GABAB agonist baclofen impaired motor sequence learning and visuomotor learning in 20 young healthy participants of both sexes. Participants trained on visuomotor and sequence learning tasks using their right hand. Transcranial magnetic stimulation (TMS) measures of corticospinal excitability, GABAA (short-interval intracortical inhibition, 2.5 ms) and GABAB (long-interval intracortical inhibition, 150 ms) receptor activation were recorded from left M1. Behaviourally, baclofen caused a significant reduction of visuomotor aftereffect (F1,137.8  = 6.133, P = 0.014) and retention (F1,130.7  = 4.138, P = 0.044), with no significant changes to sequence learning. There were no overall changes to TMS measured GABAergic inhibition with this low dose of baclofen. This result confirms the causal importance of GABAB inhibition in mediating visuomotor learning and suggests that chronic baclofen use could negatively impact aspects of motor rehabilitation.

Single-particle cryo-EM at atomic resolution.

The three-dimensional positions of atoms in protein molecules define their structure and their roles in biological processes. The more precisely atomic coordinates are determined, the more chemical information can be derived and the more mechanistic insights into protein function may be inferred. Electron cryo-microscopy (cryo-EM) single-particle analysis has yielded protein structures with increasing levels of detail in recent years1,2. However, it has proved difficult to obtain cryo-EM reconstructions with sufficient resolution to visualize individual atoms in proteins. Here we use a new electron source, energy filter and camera to obtain a 1.7 Å resolution cryo-EM reconstruction for a human membrane protein, the ß3 GABAA receptor homopentamer3. Such maps allow a detailed understanding of small-molecule coordination, visualization of solvent molecules and alternative conformations for multiple amino acids, and unambiguous building of ordered acidic side chains and glycans. Applied to mouse apoferritin, our strategy led to a 1.22 Å resolution reconstruction that offers a genuine atomic-resolution view of a protein molecule using single-particle cryo-EM. Moreover, the scattering potential from many hydrogen atoms can be visualized in difference maps, allowing a direct analysis of hydrogen-bonding networks. Our technological advances, combined with further approaches to accelerate data acquisition and improve sample quality, provide a route towards routine application of cryo-EM in high-throughput screening of small molecule modulators and structure-based drug discovery.