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As a result of evolutionary selection, the subunits of naturally occurring protein assemblies often fit together with substantial shape complementarity to generate architectures optimal for function in a manner not achievable by current design approaches. We describe a “top-down” reinforcement learning–based design approach that solves this problem using Monte Carlo tree search to sample protein conformers in the context of an overall architecture and specified functional constraints. Cryo–electron microscopy structures of the designed disk-shaped nanopores and ultracompact icosahedra are very close to the computational models. The icosohedra enable very-high-density display of immunogens and signaling molecules, which potentiates vaccine response and angiogenesis induction. Our approach enables the top-down design of complex protein nanomaterials with desired system properties and demonstrates the power of reinforcement learning in protein design.

The EFSA-approved claim that olive oil is beneficial for cardiovascular health suffers from ambiguities that lead to a vague and potentially subjective interpretation of the underlying analytical data. Misunderstandings among customers, but also market distortions are possible consequences. In this study, a rapid and simple analytical technique is presented that circumvents the ambiguity by measuring levels of putative health-promoting compounds as the equivalent of tyrosol and hydroxytyrosol, cleaving such moieties from more complex constituents such as oleuropein and oleocanthal. Since the direct hydrolysis of the olive oil is the central element of the process, the reaction temperature, time, reagent concentration and reagent type were optimized. In addition, the influence of co-solvents, which might support the intermittent miscibility of the two phases during hydrolysis, was investigated. The analytical and economic implications are discussed particularly in the context of a commonly used technique.

Lower back pain (LBP) is the most common orthopedic complaint in the United States. Physical therapy is recommended as a conservative, non-pharmacological intervention for LBP. While it is thought that skill level and effectiveness of physical therapists differ, there is little understanding regarding characteristics that distinguish high and low performing physical therapists. The purpose of this study was to compare differences in care delivery, termed treatment signatures, between high and low performing physical therapists previously differentiated by a risk-adjusted performance measure.Using previously published methodology, 1,240 physical therapists were classified as "outperforming", "meeting expectations", or "underperforming" relative to predicted change in Modified Low Back Pain Disability Questionnaire (MDQ) across patients receiving care for LBP. Patients were divided into quartiles of baseline disability per initial MDQ. Two-way analyses of variance were used to compare billed (1) active, exercise-based units per visit (UPV), (2) manual therapy UPV, (3) modality UPV, and (4) the combination of active and manual therapy UPV (broadly termed skilled UPV) by performance cohort and baseline patient disability quartile among physical therapists deemed "outperforming" and "underperforming". Tukey's post hoc tests established mean differences with 95% confidence intervals.Physical therapists that "outperformed" (n=120; 17,404 patients) used more active UPV (mean difference (diff) = 0.1, p.001), manual therapy UPV (mean diff = 0.2, p.001), and skilled UPV (mean diff = 0.3, p.001), and less modality UPV (mean diff = 0.1, P0.001) than those that "underperformed" (n=139; 21,800 patients). Tukey's post hoc tests showed that while differences in care were negligible in patients with low baseline disability, the highest performing PT cohort delivered skilled (0.4 UPV), active (0.2 UPV), and manual therapy (0.2 UPV) UPV at a significantly higher mean rate in patients with the highest baseline disability.Clinically effective physical therapists incorporated a treatment signature that included a consistent blend of skilled active and manual therapy interventions that was distinct from lower performing physical therapists. While group mean differences were relatively small, a consistent pattern emerged in which high performing physical therapists maintained a high level of skilled, one-on-one interventions across their entire caseload-while their lower performing counterparts significantly decreased use of the same interventions as baseline disability increased. These differences highlighted a treatment signature that was associated with clinically important improvements for patients with greater baseline disability. Future guideline recommendations should consider the importance of baseline disability and the consistent application of skilled active and manual therapy interventions.

Many peptide hormones form an alpha-helix upon binding their receptors1–4, and sensitive detection methods for them could contribute to better clinical management.De novoprotein design can now generate binders with high affinity and specificity to structured proteins5,6. However, the design of interactions between proteins and short helical peptides is an unmet challenge. Here, we describe parametric generation and deep learning-based methods for designing proteins to address this challenge. We show that with the RFdiffusiongenerative model, picomolar affinity binders can be generated to helical peptide targets either by noising and then denoising lower affinity designs generated with other methods, or completelyde novostarting from random noise distributions; to our knowledge these are the highest affinity designed binding proteins against any protein or small molecule target generated directly by computation without any experimental optimization. The RFdiffusiondesigns enable the enrichment of parathyroid hormone or other bioactive peptides in human plasma and subsequent detection by mass spectrometry, and bioluminescence-based protein biosensors. Capture reagents for bioactive helical peptides generated using the methods described here could aid in the improved diagnosis and therapeutic management of human diseases.7,8

The multisubunit protein assemblies that play critical roles in biology are the result of evolutionary selection for function of the entire assembly, and hence the subunits in structures such as icosahedral viral capsids often fit together with remarkable shape complementarity1,2. In contrast, the large multisubunit assemblies that have been created by de novo protein design, notably the icosahedral nanocages used in a new generation of potent vaccines3–7, have been built by first designing symmetric oligomers with cyclic symmetry and then assembling these into nanocages while keeping the internal structure fixed8–14, which results in more porous structures with less extensive shape matching between the components. Such hierarchical “bottom-up” design approaches have the advantage that one interface can be designed and validated in the context of the cyclic oligomer building block15,16, but the disadvantage that the structural and functional features of the assemblies are limited by the properties of the predesigned building blocks. To overcome this limitation, we set out to develop a “top-down” reinforcement learning based approach to protein nanomaterial design in which both the structures of the subunits and the interactions between them are built up coordinately in the context of the entire assembly. We developed a Monte Carlo tree search (MCTS) method17,18 which assembles protein monomer structures in the context of an overall architecture guided by a loss function which enables specification of any desired overall structural properties such as shape and porosity. We demonstrate the power of the approach by designing hyperstable icosahedral assemblies more compact than any previously observed protein icosahedral structure (designed or naturally occurring), that have very low porosity and are robust to fusion and display of proteins as complex as influenza hemagglutinin. CryoEM structures of two designs are very close to the computational design models. Our top-down reinforcement learning approach should enable the design of a wide variety of complex protein nanomaterials by direct optimization of overall system properties.

GN-108036 is a star-forming galaxy at $z=7.21$, and one of the most distant known sources in the Northern hemisphere. Based on observations from the NOrthern Extended Millimeter Array (NOEMA), here we report the tentative detection of the [CII] line at $\approx4\sigma$ significance. The integrated [CII] line emission is spatially offset about $\sim4$ kpc from the rest-frame ultraviolet (UV) emission. The total [CII] luminosity ($L_{\rm [CII]}=2.7\times10^8~L_{\odot}$) is consistent with the relation between [CII] luminosity and star formation rate (SFR) observed in nearby and high-$z$ star forming galaxies. More interestingly, the [CII] line is blueshifted with respect to the Ly$\alpha$ line by $980\pm10$ km s$^{-1}$. If confirmed, this corresponds to the largest velocity offset reported to date between the Ly$\alpha$ line and a non-resonant line at $z\gtrsim6$. According to trends observed in other high redshift galaxies, the large Ly$\alpha$ velocity offset in GN-108036 is consistent with its low Ly$\alpha$ equivalent width and high UV absolute magnitude. Based on Ly$\alpha$ radiative transfer models of expanding shells, the large Ly$\alpha$ velocity offset in GN-108036 could be interpreted as the presence of a large column density of hydrogen gas, and/or an outflow with a velocity of $v_{\rm out}\sim\Delta v_{\rm Ly \alpha}/2\sim500$ km s$^{-1}$. We also report the 3$\sigma$ detection of a potential galaxy companion located $\sim30$ kpc east of GN-108036, at a similar systemic velocity, and with no counterpart rest-frame UV emission., Comment: Accepted for publication in Astronomy & Astrophysics Letters, 8 pages, 6 figures

Metformin is first or second choice for oral treatment of type 2 diabetes and is licensed for its prevention. Numerous articles propagate metformin as a drug that combats diseases and lowers the risks that are associated with advanced chronological age, such as cancer, diabetes, frailty, coronary heart disease and, most recently, even COVID-19. However, no clinical studies yet exist which prove that metformin delays the onset of such age-related diseases in elderly healthy individuals. Metformin - contrary to expectations - interferes with the beneficial effects of endurance or resistance training, is suspected to rapidly lead to mild anaemia and proven to cause vitamin B12 deficiency. © 2021 The Authors. Published by Portland Press Limited. All Rights Reserved.

Remdesivir (RDV, Veklury®) is a once-daily, nucleoside ribonucleic acid polymerase inhibitor of severe acute respiratory syndrome coronavirus 2 replication. Remdesivir has been granted approvals in several countries for use in adults and children hospitalized with severe coronavirus disease 2019 (COVID-19). Inside the cell, remdesivir undergoes metabolic activation to form the intracellular active triphosphate metabolite, GS-443902 (detected in peripheral blood mononuclear cells), and ultimately, the renally eliminated plasma metabolite GS-441524. This review discusses the pre-clinical pharmacology of RDV, clinical pharmacokinetics, pharmacodynamics/concentration-QT analysis, rationale for dose selection for treatment of patients with COVID-19, and drug–drug interaction potential based on available in vitro and clinical data in healthy volunteers. Following single-dose intravenous administration over 2 h of an RDV solution formulation across the dose range of 3–225 mg in healthy participants, RDV and its metabolites (GS-704277and GS-441524) exhibit linear pharmacokinetics. Following multiple doses of RDV 150 mg once daily for 7 or 14 days, major metabolite GS-441524 accumulates approximately 1.9-fold in plasma. Based on pharmacokinetic bridging from animal data and available human data in healthy volunteers, the RDV clinical dose regimen of a 200-mg loading dose on day 1 followed by 100-mg maintenance doses for 4 or 9 days was selected for further evaluation of pharmacokinetics and safety. Results showed high intracellular concentrations of GS-443902 suggestive of efficient conversion from RDV into the triphosphate form, and further supporting this clinical dosing regimen for the treatment of COVID-19. Mathematical drug–drug interaction liability predictions, based on in vitro and phase I data, suggest RDV has low potential for drug–drug interactions, as the impact of inducers or inhibitors on RDV disposition is minimized by the parenteral route of administration and extensive extraction. Using physiologically based pharmacokinetic modeling, RDV is not predicted to be a clinically significant inhibitor of drug-metabolizing enzymes or transporters in patients infected with COVID-19 at therapeutic RDV doses. Supplementary Information The online version contains supplementary material available at 10.1007/s40262-021-00984-5.

Context: Soccer players often have a dominant (D) leg, which could influence the relative strength between the quadriceps and hamstrings. The hamstring-to-quadriceps (H:Q) ratio can be assessed on a dynamometer at various velocities to provide information on injury risk. Objective: To assess the concentric hamstrings and concentric quadriceps strength ratio (conventional H:Q ratio) assessed in D and nondominant (ND) legs at various speeds in male soccer players. Data Sources: A systematic literature search was completed from inception to 2020 in PubMed, Academic Search Ultimate, CINAHL, and SPORTDiscus. Study Selection: Keywords associated with the H:Q ratio were connected with terms for soccer players. Titles and abstracts were screened by 2 reviewers based on inclusion and exclusion criteria related to sex, playing level, language, and measurement. A total of 81 studies were reviewed and 17 studies (21%) were used. Study Design: A meta-analysis with random effects modeling generated standardized mean differences with 95% CIs between legs and speeds. Level of Evidence: Level 3. Data Extraction: A total of 38 cohorts were identified, with 14, 13, and 11 cohorts assessed at low, intermediate, and high velocities, respectively. The Quality Assessment Tool for Observational Cohort and Cross-sectional Studies from the National Institutes of Health was used. Results: The mean H:Q ratio at low velocities was 59.8 ± 9.5% in D leg and 58.6 ± 9.9% in ND leg, 64.2 ± 10.7% (D) and 63.6 ± 11.3% (ND) at the intermediate velocity, and 71.9 ± 12.7% (D) and 72.8 ± 12.7% (ND) at the high velocity. Low, intermediate, and high velocities had small effects of 0.13, 0.10, and -0.06, respectively. Conclusion: Conventional H:Q ratios vary across velocities but did not differ between D and ND limbs in male soccer players. This study may provide the foundation to establish norms and clinically meaningful differences.

There is an increasing interest in transporter induction (i.e., decreased systemic drug exposure due to increased efflux-limited absorption or transporter-mediated clearance) as a mechanism of drug-drug interactions (DDIs), although evidence of clinical relevance is still evolving. Intestinal P-glycoprotein (P-gp) and hepatic organic anion transporting polypeptides 1B (OATP1B) can be important determinants of drug absorption and disposition, as well as targets for DDIs. Current data indicate that intestinal P-gp protein levels can be induced up to threefold to fourfold in humans primarily with pregnane X receptor (PXR) activators, and that this induction can decrease the systemic exposure of drugs with P-gp efflux-limited absorption (e.g., ≤ 67% decrease in the exposure of total dabigatran following rifampin multiple oral dosing). Evaluation of the clinical relevance of P-gp induction as a DDI mechanism must consider the induction potential of the perpetrator drug for P-gp and attenuation of exposure of the victim drug in the context of its therapeutic window. Practical drug development recommendations are provided herein. Reports are contradictory on OATP1B induction by PXR activators in human hepatocytes and liver biopsies. Some clinical investigations demonstrated that rifampin pretreatment decreased exposure of OATP1B substrates, while other studies found no differences, and the potential involvement of other mechanisms in these observed DDIs cannot be definitively ruled out. Thus, further studies are needed to understand hepatic OATP1B induction and potential involvement of other mechanisms contributing to reduced exposure of OATP1B substrates. This review critically summarizes the state-of-the-art on intestinal P-gp and hepatic OATP1B induction, and highlights implications for drug development.

Background Patient-reported outcomes (PROs) have been touted as the ultimate assessment of quality medical care and have been proposed as performance measures after appropriate risk adjustment. Although spine conditions represent the most common orthopedic disorders, the most used PROs for disabilities related to the back and neck—the Modified Low Back Pain Disability Questionnaire (MDQ) and the Neck Disability Index (NDI)—have not been evaluated as performance measures. Objective The objective of this study was to benchmark physical therapists’ performance in the management of spine conditions not involving surgery through the use of risk-adjusted MDQ and NDI outcomes. Design This was a retrospective observational study. Methods Data were accessed for patients seeking physical therapy with no history of related surgery for back or neck pain (315,274 treatment episodes) between January 2015 and June 2018. Patients with complete data, including initial and matched final MDQ or NDI, were considered for analysis (182,276 patients; 2799 physical therapists). Linear models controlling for baseline PRO and patient characteristics predicted PRO change for each patient. An aggregated performance ratio of actual PRO change to predicted PRO change was calculated for each physical therapist, and then empirical bootstrapping was used to develop the median performance ratio and its confidence intervals. Physical therapists who met a 40-patient threshold for either cohort (MDQ or NDI) were classified as “outperforming,” “meeting expectations,” or “underperforming” relative to predicted values using these 95% confidence intervals. Results Performance ratios indicated that 10% and 11% of physical therapists outperformed, 79% and 78% met expectations, and 11% and 11% underperformed relative to the risk-adjusted predicted change in the MDQ (1240 therapists; 97,908 patients) and NDI (461 therapists; 26,123 patients), respectively. To demonstrate the clinical importance of risk adjustment, clinical performance was evaluated in the seemingly homogeneous subset of 208 physical therapists within 0.5 SD of the median baseline MDQ and the median actual change in the MDQ. Following risk adjustment, 2 physical therapists were classified in each of the outperforming and underperforming cohorts. Limitations The secondarily obtained observational data used were not collected for research purposes. Additionally, the analyses were limited by missing baseline information and follow-up PROs. Conclusions The risk-adjusted performance ratios for the MDQ and NDI resulted in disparate conclusions regarding the quality of care compared with the raw, unadjusted change scores. According to the baseline and unadjusted change in the MDQ, even physical therapists in the most homogeneous sample were differentiated following appropriate risk adjustment. Clinically important improvements in actual PROs were observed in the outperforming but not in the underperforming physical therapists. Clinically meaningful differences in the performance ratio are unknown and are a limitation to clinical application and an opportunity for future research.

IntroductionSleep problems are common in pregnancy but many studies have relied only on self-reported sleep measures. We studied the association between objectively measured sleep and peripartum depressive symptoms in pregnant women.Material and MethodsSleep was assessed using Actiwatch accelerometers in a sample of 163 pregnant women in the late first (weeks 11–15) or early second trimester (weeks 16–19). Depressive symptoms were assessed in gestational weeks 17, 32 and at 6 weeks post-partum using the Edinburgh Postnatal Depression Scale (EPDS). Multiple linear regression and logistic regression analyses, adjusting for age, BMI, pre-pregnancy smoking, ongoing mental health problems, trimester and season of sleep assessment were carried out to test the association between sleep and depression. Sleep was measured by total sleep time and sleep efficiency, whereas depression was indicated by depressive symptoms and depression caseness. Results are presented as unstandardized beta (B) coefficients or adjusted odds ratios (AOR) and 95% confidence intervals (CI).ResultsTotal sleep time ranged from 3 to 9 h (mean 7.1, SD 0.9) and average sleep efficiency was 83% (SD 6.0). Women with the shortest total sleep time, i.e., in the lowest quartile (

Objectives Research suggests that attendance by physical therapists at continuing education (CE) targeting the management of low back pain (LBP) and neck pain does not result in positive impacts on clinical outcomes. The aim of this study was to determine if therapists attending a self-paced 3-hour online Pain Neuroscience Education (PNE) program was associated with any observed changes to patient outcomes and also clinical practice. Methods Participants were 25 different physical therapists who treated 3,705 patients with low back pain (LBP) or neck pain before and after they had completed an online PNE CE course. Change in outcomes measures of pain and disability at discharge were compared for the patients treated before and after the therapist training. Clinical practice patterns of the therapists, including total treatment visits, duration of care, total units billed, average units billed per visit, percentage of ‘active’ billing units and percentage of ‘active and manual’ billing units, were also compared for the patient care episodes before and after the therapist training. Results There was no significant difference for change in pain scores at discharge for patients treated after therapist CE training compared to those treated before regardless of the condition (LBP or neck pain). However, patients with LBP who were treated after therapist CE training did report greater improvement in their disability scores. Also after CE training, for each episode of care, therapists tended to use less total visits, billed fewer units per visit, and billed a greater percentage of more ‘active’ and ‘active and manual’ billing units. Discussion Attending an online 3-hour CE course on PNE resulted in improved disability scores for patients with LBP, but not for those with neck pain. Changes in clinical behavior by the therapists included using less visits, billing fewer total units, and shifting to more active and manual therapy interventions. Further prospective studies with control groups should investigate the effect of therapist CE on patient outcomes and clinical practice.

We use a combination of new NOrthern Extended Millimeter Array (NOEMA) observations of the pair of [CI] transitions, the CO(7-6) line, and the dust continuum, in addition to ancillary CO(1-0) and CO(3-2) data, to study the molecular gas properties of Q1700-MD94, a massive, main-sequence galaxy at $z\approx2$. We find that for a reasonable set of assumptions for a typical massive star-forming galaxy, the CO(1-0), the [CI](1-0) and the dust continuum yield molecular gas masses that are consistent within a factor of $\sim2$. The global excitation properties of the molecular gas as traced by the [CI] and CO transitions are similar to those observed in other massive, star-forming galaxies at $z\sim2$. Our large velocity gradient (LVG) modeling using RADEX of the CO and [CI] spectral line energy distributions (SLEDs) suggests the presence of relatively warm ($T_{\rm kin}=41$K), dense ($n_{\rm H_2}=8\times10^{3}~{\rm cm}^{-3}$) molecular gas, comparable to the high-excitation molecular gas component observed in main-sequence, star-forming galaxies at $z\sim1$. The galaxy size in the CO(1-0) and CO(7-6) line emission are comparable, which suggests that the highly-excited molecular gas is distributed throughout the disk powered by intense star formation activity. To confirm this scenario will require spatially resolved observations of the CO and [CI] lines which can now be obtained with NOEMA upgraded capabilities., 7 pages, 4 figures, accepted for publication in A&A as a Letter to the Editor

Metformin is sometimes proposed to be an “anti-aging” drug, based on preclinical experiments with lower-order organisms and numerous retrospective data on beneficial health outcomes for type 2 diabetics. Large prospective, placebo-controlled trials are planned, in pilot stage or running, to find a new use (or indication) for an aging population. As one of the metformin trials has “frailty” as its endpoint, similar to a trial with a plant-derived senolytic, the latter class of novel anti-aging drugs is briefly discussed. Concerns exist not only for vitamin B12 and B6 deficiencies, but also about whether there are adverse effects of metformin on individuals who try to remain healthy by maintaining cardiovascular fitness via exercise.

Efficient genome editing methods are essential for biotechnology and fundamental research. Homologous recombination (HR) is the most versatile method of genome editing, but techniques that rely on host RecA-mediated pathways are inefficient and laborious. Phage-encoded single-stranded DNA annealing proteins (SSAPs) improve HR 1,000-fold above endogenous levels. However, they are not broadly functional. Using Escherichia coli, Lactococcus lactis, Mycobacterium smegmatis, Lactobacillus rhamnosus and Caulobacter crescentus, we investigated the limited portability of SSAPs. We find that these proteins specifically recognize the C-terminal tail of the host’s single-stranded DNA-binding protein (SSB) and are portable between species only if compatibility with this host domain is maintained. Furthermore, we find that co-expressing SSAPs with SSBs can significantly improve genome editing efficiency, in some species enabling SSAP functionality even without host compatibility. Finally, we find that high-efficiency HR far surpasses the mutational capacity of commonly used random mutagenesis methods, generating exceptional phenotypes that are inaccessible through sequential nucleotide conversions. [Figure not available: see fulltext.]

Study Objectives The brain appears to use internal models to successfully interact with its environment via active predictions of future events. Both internal models and the predictions derived from them are based on previous experience. However, it remains unclear how previously encoded information is maintained to support this function, especially in the visual domain. In the present study, we hypothesized that sleep consolidates newly encoded spatio-temporal regularities to improve predictions afterwards. Methods We tested this hypothesis using a novel sequence-learning paradigm that aimed to dissociate perceptual from motor learning. We recorded behavioral performance and high-density electroencephalography (EEG) in male human participants during initial training and during testing two days later, following an experimental night of sleep (n = 16, including high-density EEG recordings) or wakefulness (n = 17). Results Our results show sleep-dependent behavioral improvements correlated with sleep-spindle activity specifically over occipital cortices. Moreover, event-related potential (ERP) responses indicate a shift of attention away from predictable to unpredictable sequences after sleep, consistent with enhanced automaticity in the processing of predictable sequences. Conclusions These findings suggest a sleep-dependent improvement in the prediction of visual sequences, likely related to visual cortex reactivation during sleep spindles. Considering that controls in our experiments did not fully exclude oculomotor contributions, future studies will need to address the extent to which these effects depend on purely perceptual versus oculomotor sequence learning.

Aims.We aim to demonstrate that the presence and mass of an exoplanet can now be effectively derived from the astrometry of another exoplanet.Methods.We combined previous astrometry ofβPictoris b with a new set of observations from the GRAVITY interferometer. The orbital motion ofβPictoris b is fit using Markov chain Monte Carlo simulations in Jacobi coordinates. The inner planet,βPictoris c, was also reobserved at a separation of 96 mas, confirming the previous orbital estimations.Results.From the astrometry of planet b only, we can (i) detect the presence ofβPictoris c and (ii) constrain its mass to 10.04−3.10+4.53MJup. If one adds the astrometry ofβPictoris c, the mass is narrowed down to 9.15−1.06+1.08MJup. The inclusion of radial velocity measurements does not affect the orbital parameters significantly, but it does slightly decrease the mass estimate to 8.89−0.75+0.75MJup. With a semimajor axis of 2.68 ± 0.02 au, a period of 1221 ± 15 days, and an eccentricity of 0.32 ± 0.02, the orbital parameters ofβPictoris c are now constrained as precisely as those ofβPictoris b. The orbital configuration is compatible with a high-order mean-motion resonance (7:1). The impact of the resonance on the planets’ dynamics would then be negligible with respect to the secular perturbations, which might have played an important role in the eccentricity excitation of the outer planet.

Severe coronavirus disease 2019 (COVID-19) disease, including multisystem inflammatory syndrome, has been reported in children. This report summarizes development of a remdesivir physiologically-based pharmacokinetic (PBPK) model that accurately describes observed adult remdesivir and metabolites exposure and predicts pediatric remdesivir and metabolites exposure. The adult PBPK model was applied to predict pediatric remdesivir and metabolites steady-state exposures using the Pediatric Population Model in SimCYP and incorporated the relevant physiologic and mechanistic information. Model development was based on adult phase I exposure data in healthy volunteers who were administered a 200-mg loading dose of remdesivir intravenous (IV) over 0.5 hours on Day 1, then 100-mg daily maintenance doses of IV over 0.5 hours starting on Day 2 and continuing through Days 5 or 10. Simulations indicated that use of the adult therapeutic remdesivir dosage regimen (200-mg loading dose on Day 1 then 100-mg daily maintenance dose starting on Day 2) in pediatric patients ≥ 40 kg and a weight-based remdesivir dosage regimen (5-mg/kg loading dose on Day 1 then 2.5-mg/kg daily maintenance dose starting on Day 2) in pediatric patients weighing 2.5 to < 40 kg is predicted to maintain therapeutic exposures of remdesivir and its metabolites. The comprehensive PBPK model described in this report supported remdesivir dosing in planned pediatric clinical studies and dosing in the emergency use authorization and pediatric compassionate use programs that were initiated to support remdesivir as a treatment option during the pandemic.

Firsocostat (FIR: previously GS-0976), a highly sensitive OATP substrate, reduces hepatic de novo lipogenesis (DNL) by inhibiting acetyl-CoA carboxylases (ACC). Measuring the pharmacodynamic (PD) efficacy of FIR on DNL provides a unique opportunity to determine optimal dosing strategies for liver-targeted OATP substrates in settings of altered OATP function. A randomized, four-way crossover drug-drug interaction study was conducted. Hepatic DNL, a marker for ACC activity, was measured in 28 healthy volunteers after reference, single dose FIR 10 mg, FIR 10 mg plus the OATP inhibitor rifampin (RIF) 300 mg i.v., or RIF 300 mg i.v. (control for DNL effect of RIF), each separated by a 7-day washout. Samples were collected for pharmacokinetic (PK) and PD assessments through 24 hours after each treatment. Hepatic DNL and its inhibition by FIR were assessed. Twenty-four subjects completed the study. All adverse events were mild. RIF alone increased hepatic DNL area under the effect curve from time of administration up to the time of the last quantifiable concentration (AUEClast ; 35.7%). Despite a 5.2-fold increase in FIR plasma exposure (area under the concentration-time curve from zero to infinity (AUCinf )) when administered with RIF, FIR alone, and FIR + RIF had the same hepatic PD effect, 37.1% and 34.9% reduction in DNL AUEClast , respectively, compared with their respective controls. These findings indicate that large decreases in OATP activity do not alter hepatic intracellular exposure (as inferred by no change in PD) for drugs that are primarily eliminated hepatically and permeability rate-limited, such as FIR. These results support PK theory that has been difficult to test and provide practical guidance on administration of liver-targeted drugs in settings of reduced OATP function.

Objectives: Previous research indicates that concussion increases the risk of lower extremity injuries (LE) after return to sport. However, no study has examined the risk of precedent lower extremity injuries and their relationship to the development of a sport related concussion (SRC). To determine if the risk of combined injuries (LE injury-SRC) is elevated in high school athletes accounting for athlete sport and gender. Methods: 33,386 high school athletes were monitored over 4 seasons. 4223 LE injuries and 1132 concussions were reported. Injured athletes were identified by their school athletic trainer (AT) time-loss injury during a team-sponsored practice or game. ATs documented the date, mechanism, and sport of injury. Injured athletes were referred to a board-certified sports medicine physician for diagnoses and follow up care. Cumulative injury rates were calculated with 95% confidence intervals. Rate ratios were used to compare frequency of SRC after RTS following a LE injury. Comparisons were made overall cohort between those participating athletes with and without isolated and combined injuries as well as by gender. (α=0.05). Results: A cumulative incidence for athletes sustaining an isolated SRC was 2.3/100 athletes (95% CI= 2.1-2.5) and for isolated LE injury was 11.5/100 (95% CI=11.2-11.9) athletes. Athletes presenting with a LE injury had an increased risk (RR= 4.7; 95% CI = 4.2-5.2) of sustaining a subsequent SRC within 1 year when compared to athletes that did not suffer precedent LE injuries. Male athletes presenting with a LE injury had an increased risk (RR= 4.9; 95% CI = 4.2-5.7) of sustaining a subsequent SRC within 1 year when compared to male athletes that did not suffer precedent LE injuries. Female athletes presenting with a LE injury had an increased risk (RR= 4.4; 95% CI = 3.6-5.2) of sustaining a subsequent SRC within 1 year when compared to female athletes that did not suffer precedent LE injuries. In football, presenting with a LE injury had an increased risk (RR= 5.8; 95% CI = 4.5-7.4) of sustaining a subsequent SRC within 1 year when compared to football athletes that did not suffer precedent LE injuries. Conclusion: Our results are the first to show that high school athletes who suffer a time-loss LE injury are at 4.4-5.8 times increased risk to suffer a sports related concussion within the next year. Additional studies are warranted to confirm these findings.

Background Selgantolimod is a novel oral, selective Toll-like receptor 8 (TLR8) agonist in development for the treatment of chronic hepatitis B (CHB). TLR8 is an endosomal innate immune receptor and a target for treatment of viral infections. This first-in-human study investigated the safety, tolerability, pharmacokinetics (PK) and pharmacodynamics (PD) of selgantolimod in healthy volunteers. Methods Of 71 subjects enrolled, 59 received a single dose of selgantolimod (0.5, 1.5, 3 or 5 mg) or placebo, and 12 were evaluated for food effect. Safety, PK and PD activity by induction of cytokines, chemokines and acute phase proteins were assessed. PK/PD analyses were conducted. Results Single doses of 0.5–5 mg were generally safe. No serious adverse events (AEs) or AEs leading to discontinuation were reported, and most were Grade 1 in severity. Selgantolimod displayed rapid absorption and dose-proportional PK and PD activity. Food had minimal effect on PK but resulted in diminished PD activity. In PK/PD analyses, near-saturation of induction for most evaluated biomarkers occurred at the 5-mg dose. Conclusions Single doses of up to 5 mg selgantolimod were safe and induced dose-dependent PD responses. These data support evaluation of selgantolimod in combination with other agents in future clinical studies of CHB. Australian New Zealand Clinical Trials Registration: ACTRN12616001646437.

Bacterial genome editing methods are used to engineer strains for biotechnology and fundamental research. Homologous recombination (HR) is the most versatile method of genome editing, but traditional techniques using endogenous RecA-mediated pathways are inefficient and laborious. Phage encoded RecT proteins can improve HR over 1000-fold, but these proteins have limited portability between species. Using Escherichia coli, Lactococcus lactis, Mycobacterium smegmatis, Lactobacillus rhamnosus, and Caulobacter crescentus we investigated the hostlimited functionality of RecTs. We find that these proteins specifically recognize the 7 C-terminal amino acids of the bacterial single-stranded DNA-binding protein (SSB), and are portable between species only if compatibility with this host domain is maintained. Furthermore, in some species, we find that co-expressing otherwise incompatible RecTs with a paired bacterial SSB is sufficient to establish functionality. Finally, we demonstrate that high-efficiency HR surpasses the mutational capacity of more widely used error-prone methods for genome diversification, and can be used to identify exceptional phenotypes inaccessible through sequential nucleotide conversions.

The characteristics of grain boundaries and their influence on the mechanical properties have become key issues in recent research on structural materials. Especially in molybdenum, grain boundary segregation plays a significant role regarding ductility and strength. In this study as-sintered conditions of technically pure as well as boron and carbon doped molybdenum were mechanically characterized by bending tests and correspondingly analyzed by atom probe tomography to understand the differences in mechanical behavior after alloying. Strategies for improving the ductility of molybdenum are discussed with special focus on grain boundary segregation.

Rifampin demonstrated dose-dependent relative induction between cytochrome P (CYP)3A and P-glycoprotein (P-gp), organic anion transporting polypeptides (OATPs), or CYP2C9; P-gp, OATP, and CYP2C9 induction was one drug-drug interaction (DDI) category lower than that observed for CYP3A across a wide range of pregnane X receptor (PXR) agonism. The objective of this study was to determine if these relationships could be utilized to predict transporter induction by other CYP3A inducers (rifabutin and carbamazepine) and of another P-gp substrate, sofosbuvir. Healthy subjects received sofosbuvir and a six-probe drug cassette before and after 300 mg q.d. rifabutin or 300 mg b.i.d. carbamazepine. Induction of P-gp, CYP2C9, and decreased sofosbuvir exposure were successfully predicted by observed CYP3A induction. Carbamazepine induction of OATP was underpredicted, likely due to reported additional non-PXR agonism. The results demonstrate that the effect of a PXR agonist on CYP3A can be leveraged to inform on induction liability for other primarily PXR-regulated P450s/transporters, allowing for prioritization of targeted DDI assessments during new drug development.

Drug transporter and cytochrome P450 expression is regulated by shared nuclear receptors and, hence, an inducer should induce both, although the magnitude may differ. The objective of this study was to establish relative induction relationships between CYP3A and drug transporters (P-glycoprotein (P-gp), organic anion transporting polypeptide (OATP), and breast cancer resistance protein (BCRP)) or other P450s (CYP2C9 and CYP1A2) using ascending doses of the prototypical pregnane xenobiotic receptor (PXR) agonist, rifampin, to elicit weak, moderate, and strong PXR agonism. Healthy subjects received dabigatran etexilate, pravastatin, rosuvastatin, and a midazolam/tolbutamide/caffeine cocktail before and after rifampin 2, 10, 75, or 600 mg q.d. Unlike CYP3A, only moderate induction of P-gp, OATP, and CYP2C9 was observed and dose-dependent induction of P-gp, OATP, and CYP2C9 was always one drug-drug interaction category lower than observed for CYP3A, even when correcting for probe drug sensitivity. Data from this study establish proof-of-concept that P450 induction data can be leveraged to inform on the effect on transporters.

Despite being a successful diabetes type 2 drug for more than a half-century in Europe, the mode of action of metformin is still debated. It is the purpose of this review to inform the reader about most recent findings for metformin with respect to its antidiabetic activity as well as proposed benefits beyond glucose control in humans. Clinical evidence now suggests that most of metformin benefits originate from its actions in the gut, involving hormone signaling by glucagon-like peptide 1 and peptide YY. Growth differentiation factor 15, also mainly produced in the gut, was first identified as a biomarker for metformin use but is now suggested to play a significant role in e.g. weight loss of prediabetics. The pharmacokinetics of the drug in humans as basis for pharmacodynamics, resulting in high tissue levels of the intestinal wall, including the colon, proven by biopsies, is presented. A critical survey of metformin actions on mitochondria, increasing the AMP/ATP ratio but also acting as a mild uncoupler, and of postulated new cellular targets (lysosomes) is included.

As part of its role in memory consolidation, sleep has been repeatedly identified as critical for the extraction of regularities from wake experiences. However, many null results have been published as well, with no clear consensus emerging regarding the conditions that yield this sleep effect. Here, we systematically review the role of sleep in the extraction of hidden regularities, specifically those involving associative relations embedded in newly learned information. We found that the specific behavioral task used in a study had far more impact on whether a sleep effect was discovered than either the category of the cognitive processes targeted, or the particular experimental design employed. One emerging pattern, however, was that the explicit detection of hidden rules is more likely to happen when the rules are of a temporal nature (i.e., event A at time t predicts a later event B) than when they are non-temporal. We discuss this temporal rule sensitivity in reference to the compressed memory replay occurring in the hippocampus during slow-wave-sleep, and compare this effect to what happens when the extraction of regularities depends on prior knowledge and relies on structures other than the hippocampus.

Aim This open-label study investigated the effect of belatacept on cytokine levels and on the pharmacokinetics of caffeine, losartan, omeprazole, dextromethorphan and midazolam, as CYP probe substrates after oral administration of the Inje cocktail in healthy volunteers. Methods Twenty-two evaluable subjects received the Inje cocktail on Days 1, 4, 7 and 11 and belatacept infusion on Day 4. Results Since belatacept caused no major alterations to cytokine levels, there were no major effects on CYP-substrate pharmacokinetics, except for a slight (16–30%) increase in omeprazole exposure, which was probably due to omeprazole-mediated, time-dependent CYP inhibition. Belatacept did not cause major alterations in the pharmacokinetics, as measured by the geometric mean ratios and associated 90% confidence interval for area under the plasma concentration -time curve from time zero to infinity on Day 7 comparing administration with and without belatacept for caffeine (1.002 [0.914, 1.098]), dextromethorphan (1.031 [0.885, 1.200]), losartan (1.016 [0.938, 1.101)], midazolam (0.968 [0.892, 1.049]) or their respective metabolites. Conclusions Therefore, no dose adjustments of CYP substrates are indicated with belatacept coadministration.

Cellular retinoic acid binding proteins (CRABPs) bind all-trans-retinoic acid (atRA) tightly. This study aimed to determine whether atRA is channeled directly to cytochrome P450 (CYP) CYP26B1 by CRABPs, and whether CRABPs interact directly with CYP26B1. atRA bound to CRABPs (holo-CRABP) was efficiently metabolized by CYP26B1. Isotope dilution experiments showed that delivery of atRA to CYP26B1 in solution was similar with or without CRABP. Holo-CRABPs had higher affinity for CYP26B1 than free atRA, but both apo-CRABPs inhibited the formation of 4-OH-RA by CYP26B1. Similar protein-protein interactions between soluble binding proteins and CYPs may be important for other lipophilic CYP substrates.

Objective The SPF (sun protection factor) is the best known reference in the world for expressing UVB protection. The SPF is used for labelling purposes for consumer guidance. The determination of the SPF is often accomplished using an in vivo method that has been standardized. Only one in vivo SPF value from one laboratory is required for claiming an SPF value. The aim of this study was to determine the relevance of the in vivo SPF value in terms of interlaboratory variability for claiming purposes and to determine whether some minimum number of different in vivo SPF values from different laboratories would improve the reliability of the final SPF claimed. Methods A large population of 44 different commercially available sunscreen formulations from the European market has been investigated, covering various product types. The majority of the SPF values claimed ranged from 15 to 50+. For each product, at least three different in vivo SPF values tested in different laboratories have been gathered, and a variety of statistical analyses have been performed. Results For each SPF category from the average of all samples, the minimum and maximum in vivo-measured SPF values from the different laboratories would lead to labels claiming different levels of SPF for the same product. Indeed, with coefficients of variation for in vivo SPF determinations that exceed 50% in some cases, as an example, the same product could in reality be claimed to be SPF 30, SPF 50 or SPF 50+. Conclusion In this study, the authors demonstrated that using only one in vivo SPF value from one laboratory may actually challenge the reliability of the final SPF claim significantly. To reduce the consumer health risk by ensuring the reliability of the SPF claim, an average from at least 3 (ideally 4) different in vivo SPF values should be compulsory.

OBJECTIVE Our previous paper (Part I: Principle and mathematical aspects) presented a new reliable in vitro sun protection factor (SPF) method and demonstrated it to be reproducible and correlated with the in vivo method. Nevertheless, the relevance of an international method should to be adaptable to all products on the market and demonstrated with a blind test. Thus, the aim of this second article was to focus on the practical aspects and implementation (Part II) of a large population of different commercially available sunscreen formulations to obtain similar in vivo SPF results for the purpose of labelling. METHODS The method uses the spectroradiometric measurement of residual ultraviolet (UV) through the sample that was applied on a substrate with a robotic appliance. The method has been demonstrated to be highly reliable, and it is based on a multisubstrate solution with a single UV pre-irradiation dose. Furthermore, different categories of the product were studied to identify a reliable and universal in vitro SPF method. RESULTS Based on different sunscreens products classified into 5 different groups (emulsion, oil, alcohol, stick and powder), it was demonstrated that our method has good reproducibility and accuracy compared with the clinical SPF method. Indeed, the mean coefficient of variation (CV%) was approximately 7%, and the coefficient of correlation reached approximately 0.8-1.0 for different types of tested products. CONCLUSION Our second paper concludes that the new in vitro SPF method (based on 113 sunscreen products from the Parts I and II) is clearly adaptable for the SPF labelling purpose on any product type because it is non-invasive, less expensive, more practical and more reliable if performed under strict conditions.

Background Bruton's tyrosine kinase (BTK) is a key component of the B-cell receptor (BCR) pathway and a clinically validated target for small molecule inhibitors such as ibrutinib in the treatment of B-cell malignancies. Tirabrutinib (GS-4059/ONO-4059) is a selective, once daily, oral BTK inhibitor with clinical activity against many relapsed/refractory B-cell malignancies. Methods Covalent binding of tirabrutinib to BTK Cys-481 was assessed by LC-MSMS analysis of BTK using compound as a variable modification search parameter. Inhibition potency of tirabrutinib, ibrutinib, acalabrutinib, and spebrutinib against BTK and related kinases was studied in a dose-dependent manner either after a fixed incubation time (as used in conventional IC50 studies) or following a time course where inactivation kinetics were measured. Results Tirabrutinib irreversibly and covalently binds to BTK Cys-481. The inactivation efficiency kinact/Ki was measured and used to calculate selectivity among different kinases for each of the four inhibitors studied. Tirabrutinib showed a kinact/Ki value of 2.4 ± 0.6 × 104 M−1 s−1 for BTK with selectivity against important off-targets. Conclusions For the BTK inhibitors tested in this study, analysis of the inactivation kinetics yielded a more accurate measurement of potency and selectivity than conventional single-time point inhibition measurements. Subtle but clear differences were identified between clinically tested BTK inhibitors which may translate into differentiated clinical efficacy and safety. General significance This is the first study that offers a detailed side-by-side comparison of four clinically-relevant BTK inhibitors with respect to their inactivation of BTK and related kinases.

Introduction As patient-reported outcome measures (PROMs) continue to evolve as vital measures of patient status, it may be useful to identify efficiently, Single Assessment Numeric Evaluation (SANE) scores that are valid and related to the patient's specific functional needs. Objective To evaluate the concurrent validity between SANE scores and commonly used body region-specific functional PROMs, functional percentage change scores, and total visits in patients with musculoskeletal (MSK) disorders. Methods 479 patients completed the SANE and one of the following PROMs at physical therapy discharge: Modified Low Back Pain Disability Questionnaire [MDQ], Neck Disability Index [NDI], Penn Shoulder Score [PSS], International Knee Documentation Committee [IKDC], Lower Extremity Functional Scale [LEFS]. Pearson correlation coefficients were used to assess the relationship between SANE and the aforementioned outcomes and total visits. Results The SANE was moderately negatively correlated with the MDQ and NDI at discharge. There were high positive correlations between SANE and PSS and IKDC and moderate positive correlation between SANE and LEFS. The SANE and MDQ and IKDQ demonstrated low positive correlation for functional percentage change scores, and the SANE and NDI demonstrated moderate positive correlation for functional percentage change scores. For total visits outcome, there was a negligible negative correlation between SANE and MDQ and NDI at discharge. Conclusion The SANE exhibits acceptable concurrent validity across all investigated PROMs at physical therapy discharge. However, inconsistent relationships across body regions for functional percentage change and total visits suggest differences in these values as compared to raw discharge scores.

The retinal rod pathway, featuring dedicated rod bipolar cells (RBCs) and AII amacrine cells, has been intensely studied in placental mammals. Here, we analyzed the rod pathway in a nocturnal marsupial, the South American opossum Monodelphis domestica to elucidate whether marsupials have a similar rod pathway. The retina was dominated by rods with densities of 338,000-413,000/mm². Immunohistochemistry for the RBC-specific marker protein kinase Cα (PKCα) and the AII cell marker calretinin revealed the presence of both cell types with their typical morphology. This is the first demonstration of RBCs in a marsupial and of the integration of RBCs and AII cells in the rod signaling pathway. Electron microscopy showed invaginating synaptic contacts of the PKCα-immunoreactive bipolar cells with rods; light microscopic co-immunolabeling for the synaptic ribbon marker CtBP2 confirmed dominant rod contacts. The RBC axon terminals were mostly located in the innermost stratum S5 of the inner plexiform layer (IPL), but had additional side branches and synaptic varicosities in strata S3 and S4, with S3-S5 belonging to the presumed functional ON sublayer of the IPL, as shown by immunolabeling for the ON bipolar cell marker Gγ13. Triple-immunolabeling for PKCα, calretinin and CtBP2 demonstrated RBC synapses onto AII cells. These features conform to the pattern seen in placental mammals, indicating a basically similar rod pathway in M. domestica. The density range of RBCs was 9,900-16,600/mm2, that of AII cells was 1,500-3,260/mm2. The numerical convergence (density ratio) of 146-156 rods to 4.7-6.0 RBCs to 1 AII cell is within the broad range found among placental mammals. For comparison, we collected data for the Australian nocturnal dunnart Sminthopsis crassicaudata, and found it to be similar to M. domestica, with rod-contacting PKCα-immunoreactive bipolar cells that had axon terminals also stratifying in IPL strata S3-S5.

The Richard F. Caris Mirror Lab at the University of Arizona continues the production of 8.4 m lightweight honeycomb segments for the primary mirror of the Giant Magellan Telescope. GMT will have a center segment surrounded by six identical off-axis segments, plus an additional off-axis segment to allow continuous operation as segments are removed for coating. Production highlights of the last two years include the spin-casting of Segment 5, preliminary polishing of Segment 2, and completion of the rear surface processing for Segments 3 and 4. We completed a preliminary design of the significant modifications of the test systems required for Segment 4, the center segment. We finished an upgrade of the 8.4 m polishing machine; both the upgrade and experience gained with Segment 1 have contributed to much faster polishing convergence for Segment 2. Prior to polishing Segment 2, we verified the stability and accuracy of the measurement systems by re-measuring Segment 1, achieving good agreement among multiple independent tests as well as good agreement with the original acceptance tests of Segment 1.