Screening for lung cancer with computed tomography: protocol for systematic reviews for the Canadian Task Force on Preventive Health Care.

PURPOSE: Lung cancer is the leading cause of cancer deaths in Canada, and because early cancers are often asymptomatic screening aims to prevent mortality by detecting cancer earlier when treatment is more likely to be curative. These reviews will inform updated recommendations by the Canadian Task Force on Preventive Health Care on screening for lung cancer. METHODS: We will update the review on the benefits and harms of screening with CT conducted for the task force in 2015 and perform de novo reviews on the comparative effects between (i) trial-based selection criteria and use of risk prediction models and (ii) trial-based nodule classification and different nodule classification systems and on patients' values and preferences. We will search Medline, Embase, and Cochrane Central (for questions on benefits and harms from 2015; comparative effects from 2012) and Medline, Scopus, and EconLit (for values and preferences from 2012) via peer-reviewed search strategies, clinical trial registries, and the reference lists of included studies and reviews. Two reviewers will screen all citations (including those in the previous review) and base inclusion decisions on consensus or arbitration by another reviewer. For benefits (i.e., all-cause and cancer-specific mortality and health-related quality of life) and harms (i.e., overdiagnosis, false positives, incidental findings, psychosocial harms from screening, and major complications and mortality from invasive procedures as a result of screening), we will include studies of adults in whom lung cancer is not suspected. We will include randomized controlled trials comparing CT screening with no screening or alternative screening modalities (e.g., chest radiography) or strategies (e.g., CT using different screening intervals, classification systems, and/or patient selection via risk models or biomarkers); non-randomized studies, including modeling studies, will be included for the comparative effects between trial-based and other selection criteria or nodule classification methods. For harms (except overdiagnosis) we will also include non-randomized and uncontrolled studies. For values and preferences, the study design may be any quantitative design that either directly or indirectly measures outcome preferences on outcomes pertaining to lung cancer screening. We will only include studies conducted in Very High Human Development Countries and having full texts in English or French. Data will be extracted by one reviewer with verification by another, with the exception of result data on mortality and cancer incidence (for calculating overdiagnosis) where duplicate extraction will occur. If two or more studies report on the same comparison and it is deemed suitable, we will pool continuous data using a mean difference or standardized mean difference, as applicable, and binary data using relative risks and a DerSimonian and Laird model unless events are rare (< 1%) where we will pool odds ratios using Peto's method or (if zero events) the reciprocal of the opposite treatment arm size correction. For pooling proportions, we will apply suitable transformation (logit or arcsine) depending on the proportions of events. If meta-analysis is not undertaken we will synthesize the data descriptively, considering clinical and methodological differences. For each outcome, two reviewers will independently assess within- and across-study risk of bias and rate the certainty of the evidence using GRADE (Grading of Recommendations Assessment, Development, and Evaluation), and reach consensus. DISCUSSION: Since 2015, additional trials and longer follow-ups or additional data (e.g., harms, specific patient populations) from previously published trials have been published that will improve our understanding of the benefits and harms of screening. The systematic review of values and preferences will allow fulsome insights that will inform the balance of benefits and harms. SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRD42022378858.

Four-dimensional treatment planning strategies for dynamic tumor tracking.

INTRODUCTION: Dynamic tumor tracking (DTT) is a motion management technique where the radiation beam follows a moving tumor in real time. Not modelling DTT beam motion in the treatment planning system leaves an organ at risk (OAR) vulnerable to exceeding its dose limit. This work investigates two planning strategies for DTT plans, the "Boolean OAR Method" and the "Aperture Sorting Method," to determine if they can successfully spare an OAR while maintaining sufficient target coverage. MATERIALS AND METHODS: A step-and-shoot intensity modulated radiation therapy (sIMRT) treatment plan was re-optimized for 10 previously treated liver stereotactic ablative radiotherapy patients who each had one OAR very close to the target. Two planning strategies were investigated to determine which is more effective at sparing an OAR while maintaining target coverage: (1) the "Boolean OAR Method" created a union of an OAR's contours from two breathing phases (exhale and inhale) on the exhale phase (the planning CT) and protected this combined OAR during plan optimization, (2) the "Aperture Sorting Method" assigned apertures to the breathing phase where they contributed the least to an OAR's maximum dose. RESULTS: All 10 OARs exceeded their dose constraints on the original plan four-dimensional (4D) dose distributions and average target coverage was V100% = 91.3% ± 2.9% (ranging from 85.1% to 94.8%). The "Boolean OAR Method" spared 7/10 OARs, and mean target coverage decreased to V100% = 87.1% ± 3.8% (ranging from 80.7% to 93.7%). The "Aperture Sorting Method" spared 9/10 OARs and the mean target coverage remained high at V100% = 91.7% ± 2.8% (ranging from 84.9% to 94.5%). CONCLUSIONS: 4D planning strategies are simple to implement and can improve OAR sparing during DTT treatments. The "Boolean OAR Method" improved sparing of OARs but target coverage was reduced. The "Aperture Sorting Method" further improved sparing of OARs and maintained target coverage.

Recommandations sur le dépistage pour la prévention primaire des fractures de fragilisation.

CONTEXTE: Les fractures de fragilisation sont un important problème de santé chez les adultes âgés et peuvent entraîner des incapacités, des hospitalisations et le placement en établissement de soins de longue durée, en plus de nuire à la qualité de vie. La présente ligne directrice du Groupe d'étude canadien sur les soins de santé préventifs (le Groupe d'étude) formule des recommandations fondées sur des données probantes au sujet du dépistage pour la prévention des fractures de fragilisation chez les personnes âgées de 40 ans et plus vivant dans la collectivité qui ne sont pas sous traitement pharmacologique préventif. MÉTHODES: Nous avons commandé des revues systématiques sur les bénéfices et les préjudices du dépistage, l'exactitude prédictive des outils d'évaluation du risque, les bénéfices du traitement, ainsi que l'acceptabilité de celui-ci par les patients. Nous avons analysé les préjudices des traitements au moyen d'un examen rapide de revues systématiques. Nous avons en outre analysé les valeurs et les préférences des patients par l'entremise de groupes de discussion et auprès d'intervenants mobilisés à certains moments clés, tout au long du projet. Nous avons utilisé l'approche méthodologique GRADE (Grading of Recommendations, Assessment, Development and Evaluation) afin de déterminer la certitude des données probantes pour chacune des issues cliniques ainsi que la force des recommandations, et nous avons appliqué les lignes directrices de l'instrument AGREE (Appraisal of Guidelines for Research and Evaluation), du Guidelines International Network (GIN) et du guide de rédaction Guidance for Reporting Involvement of Patients and the Public (GRIPP 2). RECOMMANDATIONS: Nous recommandons un dépistage débutant par une estimation du risque pour la prévention des fractures de fragilisation chez les femmes de 65 ans et plus. Le dépistage se fait d'abord au moyen de l'outil canadien FRAX, qui mesure le risque de fracture, sans densité minérale osseuse (DMO). Le score FRAX devrait guider la prise de décision partagée entourant les bénéfices et les préjudices potentiels de la pharmacothérapie préventive. Après cette discussion, si une pharmacothérapie préventive est envisagée, les médecins devraient demander une mesure de la DMO par absorptiométrie à rayons X biphotonique (DEXA) du col du fémur, puis réévaluer le risque de fracture en intégrant le score T de la DMO au score FRAX (recommandation conditionnelle, données de faible certitude). Nous ne recommandons pas le dépistage chez les femmes de 40­64 ans et les hommes de 40 ans et plus (recommandation forte, données de très faible certitude). Ces recommandations s'appliquent aux personnes vivant dans la collectivité qui ne sont pas sous pharmacothérapie pour la prévention des fractures de fragilisation. INTERPRÉTATION: Le dépistage débutant par une estimation du risque chez les femmes de 65 ans et plus facilite la prise de décision partagée et permet aux patientes d'envisager la pharmacothérapie préventive en fonction de leur propre risque (avant DMO). Le fait de ne pas recommander le dépistage chez les hommes et les femmes plus jeunes rappelle l'importance des bonnes pratiques cliniques, en vertu desquelles les médecins doivent demeurer à l'affût de tout changement de l'état de santé des personnes qui pourrait indiquer qu'elles ont subi une fracture de fragilisation ou pourraient y être plus sujettes.

Recommendations on screening for primary prevention of fragility fractures.

BACKGROUND: Fragility fractures are a major health concern for older adults and can result in disability, admission to hospital and long-term care, and reduced quality of life. This Canadian Task Force on Preventive Health Care (task force) guideline provides evidence-based recommendations on screening to prevent fragility fractures in community-dwelling individuals aged 40 years and older who are not currently on preventive pharmacotherapy. METHODS: We commissioned systematic reviews on benefits and harms of screening, predictive accuracy of risk assessment tools, patient acceptability and benefits of treatment. We analyzed treatment harms via a rapid overview of reviews. We further examined patient values and preferences via focus groups and engaged stakeholders at key points throughout the project. We used the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach to determine the certainty of evidence for each outcome and strength of recommendations, and adhered to Appraisal of Guidelines for Research and Evaluation (AGREE), Guidelines International Network and Guidance for Reporting Involvement of Patients and the Public (GRIPP-2) reporting guidance. RECOMMENDATIONS: We recommend "risk assessment-first" screening for prevention of fragility fractures in females aged 65 years and older, with initial application of the Canadian clinical Fracture Risk Assessment Tool (FRAX) without bone mineral density (BMD). The FRAX result should be used to facilitate shared decision-making about the possible benefits and harms of preventive pharmacotherapy. After this discussion, if preventive pharmacotherapy is being considered, clinicians should request BMD measurement using dual-energy x-ray absorptiometry (DXA) of the femoral neck, and re-estimate fracture risk by adding the BMD T-score into FRAX (conditional recommendation, low-certainty evidence). We recommend against screening females aged 40-64 years and males aged 40 years and older (strong recommendation, very low-certainty evidence). These recommendations apply to community-dwelling individuals who are not currently on pharmacotherapy to prevent fragility fractures. INTERPRETATION: Risk assessment-first screening for females aged 65 years and older facilitates shared decision-making and allows patients to consider preventive pharmacotherapy within their individual risk context (before BMD). Recommendations against screening males and younger females emphasize the importance of good clinical practice, where clinicians are alert to changes in health that may indicate the patient has experienced or is at higher risk of fragility fracture.

Patient-reported disease impact of systemic lupus erythematosus with active joint symptoms: Results from the systemic lupus erythematosus-update survey.

BACKGROUND: Many people with systemic lupus erythematosus (SLE) experience joint pain, swelling, and stiffness. These joint symptoms are associated with problems in physical functioning and work disability. We used survey data from adults with SLE to explore the burden and impact of joint symptoms. METHODS: SLE-UPDATE was a 2019 cross-sectional US survey of adults with SLE. We compared respondents with "currently active" joint symptoms' and those "without currently active" joint symptoms. The active joint cohort comprised survey respondents who self-reported current "stiffness in joints" or "pain/swelling in joints" and who had moderate to severe joint pain (Worst Joint Pain Numeric Rating Scale [NRS] score ≥ 4). Respondents not fulfilling these criteria were included in the non-active joint cohort. Outcomes included frequency and severity of pain, patient-reported outcomes (LupusPRO™ and Work Productivity and Activity Impairment: Lupus [WPAI-Lupus]), satisfaction with current treatments, and importance of different treatment goals. RESULTS: More respondents in the active joint cohort (N = 285) than in the non-active joint cohort (N = 215) reported pain most or all the time over the preceding 7 days (77.5% vs. 32.1%, p < .0001), fibromyalgia (45% vs. 12%, p < .0001), and higher (worse) mean scores on the Worst Pain NRS (6.5 vs. 4.8, p < .0001) and Worst Joint Pain NRS (6.7 vs. 4.5, p < .0001). Mean Lupus PRO health-related quality of life (HRQoL) total score was lower (worse) in the active joint cohort (48.9 vs. 64.1, p < .0001). WPAI-Lupus scores indicated greater work productivity losses and activity impairment in the active joint cohort. More respondents in the active joint cohort than in the non-active joint cohort were neutral or not satisfied with current treatments and rated reducing pain as a "very important" treatment goal (26.7% vs. 18.1%). CONCLUSIONS: Respondents with SLE and active joint manifestations in addition to having more pain report lower HRQoL and were less satisfied with their current treatments. Comorbid fibromyalgia may play a role in joint symptoms in patient with SLE joint manifestations. There is an unmet need for new therapeutic options to reduce joint symptom burden among patients with SLE.

Interventions to address potentially inappropriate prescriptions and over-the-counter medication use among adults 65 years and older in primary care settings: protocol for a systematic review.

PURPOSE: To inform recommendations by the Canadian Task Force on Preventive Health Care on potentially inappropriate prescribing and over-the-counter (OTC) medication use among adults aged 65 years and older in primary care settings. This protocol outlines the planned scope and methods for a systematic review of the benefits and harms and acceptability of interventions to reduce potentially inappropriate prescriptions and OTC medication use. METHODS: De novo systematic reviews will be conducted to synthesize the available evidence on (a) the benefits and harms of interventions to reduce potentially inappropriate prescriptions and OTC medications compared to no intervention, usual care, or non- or minimally active intervention among adults aged 65 years and older and (b) the acceptability of these interventions or attributes among patients. Outcomes of interest for the benefits and harms review are all-cause mortality, hospitalization, non-serious adverse drug reactions, quality of life, emergency department visits, injurious falls, medical visits, and the number of medications (and number of pills). Outcomes for the acceptability review are the preference for and relative importance of different interventions or their attributes. For the benefits and harms review, we will search MEDLINE, Embase, and Cochrane Central Register of Controlled Trials for randomized controlled trials. For the acceptability review, we will search MEDLINE, Embase, PsycInfo, Cochrane Central Register of Controlled Trials, and the NHS Economic Evaluation Database for experimental and observational studies with a comparator. Websites of relevant organizations, other grey literature sources, and reference lists of included studies and reviews will be searched. Title and abstract screening will be completed by two independent reviewers using the liberal accelerated approach. Full-text review, data extraction, risk of bias assessments, and GRADE (Grading of Recommendations Assessment, Development and Evaluation) will be completed independently by two reviewers, with any disagreements resolved by consensus or by consulting with a third reviewer. The GRADE approach will be used to assess the certainty of the evidence for outcomes. DISCUSSION: The results of this systematic review will be used by the Canadian Task Force on Preventive Health Care to inform their recommendation on potentially inappropriate prescribing and OTC medication use among adults aged 65 years and older. SYSTEMATIC REVIEW REGISTRATION: PROSPERO (KQ1: CRD42022302313; KQ2: CRD42022302324); Open Science Framework ( https://osf.io/urj4b/ ).

Family Experiences with Care for Children with Inherited Metabolic Diseases in Canada: A Cross-Sectional Survey.

BACKGROUND AND OBJECTIVE: Children with inherited metabolic diseases often require complex and highly specialized care. Patient and family-centered care can improve health outcomes that are important to families. This study aimed to examine experiences of family caregivers (parents/guardians) of children diagnosed with inherited metabolic diseases with healthcare to inform strategies to improve those experiences. METHODS: A cross-sectional mailed survey was conducted of family caregivers recruited from an ongoing cohort study. Participants rated their healthcare experiences during their child's visits to five types of healthcare settings common for inherited metabolic diseases: the metabolic clinic, the emergency department, hospital inpatient units, the blood laboratory, and the pharmacy. Participants provided narrative descriptions of any memorable negative or positive experiences. RESULTS: There were 248 respondents (response rate 49%). Caregivers were generally very or somewhat satisfied with the care provided at each care setting. Appropriate treatment, provider knowledge, provider communication, and care coordination were deemed essential aspects of satisfaction with care by the majority of participants across many settings. Memorable negative experiences were reported by 8-22% of participants, varying by setting. Among participants who reported memorable negative experiences, contributing factors included providers' demeanor, lack of communication, lack of involvement of the family, and disregard of an emergency protocol letter provided by the family. CONCLUSIONS: While caregivers' satisfaction with care for children with inherited metabolic diseases was high, we identified gaps in family-centered care and factors contributing to negative experiences that are important to consider in the future development of strategies to improve pediatric care for inherited metabolic diseases.

Core Outcome Sets for Medium-Chain Acyl-CoA Dehydrogenase Deficiency and Phenylketonuria.

BACKGROUND: Evidence to guide treatment of pediatric medium-chain acyl-coenzyme A dehydrogenase (MCAD) deficiency and phenylketonuria (PKU) is fragmented because of large variability in outcome selection and measurement. Our goal was to develop core outcome sets (COSs) for these diseases to facilitate meaningful future evidence generation and enhance the capacity to compare and synthesize findings across studies. METHODS: Parents and/or caregivers, health professionals, and health policy advisors completed a Delphi survey and participated in a consensus workshop to select core outcomes from candidate lists of outcomes for MCAD deficiency and PKU. Delphi participants rated the importance of outcomes on a nine-point scale (1-3: not important, 4-6: important but not critical, 7-9: critical). Candidate outcomes were progressively narrowed down over 3 survey rounds. At the workshop, participants evaluated the remaining candidate outcomes using an adapted nominal technique, open discussion, and voting. After the workshop, we finalized the COSs and recommended measurement instruments for each outcome. RESULTS: There were 85, 61, and 53 participants across 3 Delphi rounds, respectively. The candidate core outcome lists were narrowed down to 20 outcomes per disease to be discussed at the consensus workshop. Voting by 18 workshop participants led to COSs composed of 8 and 9 outcomes for MCAD deficiency and PKU, respectively, with measurement recommendations. CONCLUSIONS: These are the first known pediatric COSs for MCAD deficiency and PKU. Adoption in future studies will help to ensure best use of limited research resources to ultimately improve care for children with these rare diseases.

Patient Experiences, Satisfaction, and Expectations with Current Systemic Lupus Erythematosus Treatment: Results of the SLE-UPDATE Survey.

OBJECTIVES: To provide information on systemic lupus erythematosus (SLE) patients' experiences, satisfaction, and expectations with treatments and examine the association between treatment satisfaction and patient-reported outcomes (PRO). METHODS: A cross-sectional, non-interventional, online survey of US adult patients with SLE was conducted in 2019. The survey consisted of 104 questions about SLE and the following PRO instruments: LupusPRO™, Functional Assessment of Chronic Illness Therapy (FACIT) Fatigue, Work Productivity and Activity Impairment (WPAI), an 11-point Worst Pain Numerical Rating scale (NRS), and an 11-point Worst Joint Pain NRS. RESULTS: Five hundred participants (75% female, 76% White/Caucasian, mean age 42.6 ± 12.7 years, 63% with an associate degree or higher) completed the survey. Most participants were "completely" or "somewhat satisfied" with their treatments, although satisfaction rates were lower for corticosteroids (65%), immunosuppressants (71%), and anti-malarials (55%) than for belimumab (intravenous or subcutaneous) (86%) and rituximab (94%). Treatments were more often considered "burdensome" or "very burdensome" for belimumab (67%) and rituximab (63%) than for corticosteroids (48%), immunosuppressants (49%), and anti-malarials (30%). Pain and productivity assessments supported substantial impairment for the majority of participants, even those who indicated that they were completely satisfied with treatments. The treatment goals most commonly reported as "very important" were reducing fatigue, pain, and the frequency or severity of flares. Three-quarters of participants (76.6%) indicated that their physician's goals for their therapy matched their own goals "very" or "somewhat closely." Despite high levels of satisfaction, most participants (63.0%) indicated that their physicians had not asked about their treatment goals during the past 3 months. CONCLUSION: SLE patients reported high rates of satisfaction with current therapies despite identifying substantial treatment burdens, residual pain, and fatigue. Reduced fatigue, pain, and flares were the most important treatment goals for these patients.

Four-dimensional dose calculations for dynamic tumour tracking with a gimbal-mounted linear accelerator.

PURPOSE: In this study we present a novel method for re-calculating a treatment plan on different respiratory phases by accurately modeling the panning and tilting beam motion during DTT (the "rotation method"). This method is used to re-calculate the dose distribution of a plan on multiple breathing phases to accurately assess the dosimetry. METHODS: sIMRT plans were optimized on a breath hold computed tomography (CT) image taken at exhale (BHexhale ) for 10 previous liver stereotactic ablative radiotherapy patients. Our method was used to re-calculate the plan on the inhale (0%) and exhale (50%) phases of the four-dimensional CT (4DCT) image set. The dose distributions were deformed to the BHexhale CT and summed together with proper weighting calculated from the patient's breathing trace. Subsequently, the plan was re-calculated on all ten phases using our method and the dose distributions were deformed to the BHexhale CT and accumulated together. The maximum dose for certain organs at risk (OARs) was compared between calculating on two phases and all ten phases. RESULTS: In total, 26 OARs were examined from 10 patients. When the dose was calculated on the inhale and exhale phases six OARs exceeded their dose limit, and when all 10 phases were used five OARs exceeded their limit. CONCLUSION: Dynamic tumor tracking plans optimized for a single respiratory phase leave an OAR vulnerable to exceeding its dose constraint during other respiratory phases. The rotation method accurately models the beam's geometry. Using deformable image registration to accumulate dose from all 10 breathing phases provides the most accurate results, however it is a time consuming procedure. Accumulating the dose from two extreme breathing phases (exhale and inhale) and weighting them properly provides accurate results while requiring less time. This approach should be used to confirm the safety of a DTT treatment plan prior to delivery.

Fall prevention interventions for older community-dwelling adults: systematic reviews on benefits, harms, and patient values and preferences.

BACKGROUND: An estimated 20-30% of community-dwelling Canadian adults aged 65 years or older experience one or more falls each year. Fall-related injuries are a leading cause of hospitalization and can lead to functional independence. Many fall prevention interventions, often based on modifiable risk factors, have been studied. Apart from the magnitude of the benefits and harms from different interventions, the preferences of older adults for different interventions as well as the relative importance they place on the different potential outcomes may influence recommendations by guideline panels. These reviews on benefits and harms of interventions, and on patient values and preferences, will inform the Canadian Task Force on Preventive Health Care to develop recommendations on fall prevention for primary care providers. METHODS: To review the benefits and harms of fall prevention interventions, we will update a previous systematic review of randomized controlled trials with adaptations to modify the classification of interventions and narrow the scope to community-dwelling older adults and primary-care relevant interventions. Four databases (MEDLINE, Embase, Cochrane Central Register of Controlled Trials, Ageline), reference lists, trial registries, and relevant websites will be searched, using limits for randomized trials and date (2016 onwards). We will classify interventions according to the Prevention of Falls Network Europe (ProFANE) Group's taxonomy. Outcomes include fallers, falls, injurious falls, fractures, hip fractures, institutionalization, health-related quality of life, functional status, and intervention-related adverse effects. For studies not included in the previous review, screening, study selection, data extraction on outcomes, and risk of bias assessments will be independently undertaken by two reviewers with consensus used for final decisions. Where quantitative analysis is suitable, network or pairwise meta-analysis will be conducted using a frequentist approach in Stata. Assessment of the transitivity and coherence of the network meta-analyses will be undertaken. For the reviews on patient preferences and outcome valuation (relative importance of outcomes), we will perform de novo reviews with searches in three databases (MEDLINE, PsycInfo, and CINAHL) and reference lists for cross-sectional, longitudinal quantitative, or qualitative studies published from 2000. Selection, data extraction, and risk of bias assessments suitable for each study design will be performed in duplicate. The analysis will be guided by a narrative synthesis approach, which may include meta-analysis for health-state utilities. We will use the CINeMa approach to a rate the certainty of the evidence for outcomes on intervention effects analyzed using network meta-analysis and the GRADE approach for all other outcomes. DISCUSSION: We will describe the flow of literature and characteristics of all studies and present results of all analyses and summary of finding tables. We will compare our findings to others and discuss the limitations of the reviews and the available literature. SYSTEMATIC REVIEW REGISTRATION: This protocol has not been registered.

The internal structure and geodynamics of Mars inferred from a 4.2-Gyr zircon record.

Combining U-Pb ages with Lu-Hf data in zircon provides insights into the magmatic history of rocky planets. The Northwest Africa (NWA) 7034/7533 meteorites are samples of the southern highlands of Mars containing zircon with ages as old as 4476.3 ± 0.9 Ma, interpreted to reflect reworking of the primordial Martian crust by impacts. We extracted a statistically significant zircon population (n = 57) from NWA 7533 that defines a temporal record spanning 4.2 Gyr. Ancient zircons record ages from 4485.5 ± 2.2 Ma to 4331.0 ± 1.4 Ma, defining a bimodal distribution with groupings at 4474 ± 10 Ma and 4442 ± 17 Ma. We interpret these to represent intense bombardment episodes at the planet's surface, possibly triggered by the early migration of gas giant planets. The unradiogenic initial Hf-isotope composition of these zircons establishes that Mars's igneous activity prior to ∼4.3 Ga was limited to impact-related reworking of a chemically enriched, primordial crust. A group of younger detrital zircons record ages from 1548.0 ± 8.8 Ma to 299.5 ± 0.6 Ma. The only plausible sources for these grains are the temporally associated Elysium and Tharsis volcanic provinces that are the expressions of deep-seated mantle plumes. The chondritic-like Hf-isotope compositions of these zircons require the existence of a primitive and convecting mantle reservoir, indicating that Mars has been in a stagnant-lid tectonic regime for most of its history. Our results imply that zircon is ubiquitous on the Martian surface, providing a faithful record of the planet's magmatic history.

Overall survival in patients with BRAF-mutant melanoma receiving encorafenib plus binimetinib versus vemurafenib or encorafenib (COLUMBUS): a multicentre, open-label, randomised, phase 3 trial.

BACKGROUND: Encorafenib plus binimetinib and encorafenib alone improved progression-free survival compared with vemurafenib in patients with BRAFV600-mutant melanoma in the COLUMBUS trial. Here, we report the results of the secondary endpoint of overall survival. METHODS: COLUMBUS was a two-part, randomised, open-label, phase 3 study done at 162 hospitals in 28 countries. Eligible patients were aged at least 18 years with histologically confirmed, locally advanced, unresectable, or metastatic cutaneous melanoma, or unknown primary melanoma, BRAFV600E or BRAFV600K mutation, an Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1, and were treatment naive or had progressed on or after first-line immunotherapy. In part 1 of the study, patients were randomly assigned (1:1:1) by use of interactive response technology to receive oral encorafenib 450 mg once daily plus oral binimetinib 45 mg twice daily (encorafenib plus binimetinib group), oral encorafenib 300 mg once daily (encorafenib group), or oral vemurafenib 960 mg twice daily (vemurafenib group). Randomisation was stratified by the American Joint Committee on Cancer stage, ECOG performance status, and BRAF mutation status. The primary outcome of the trial, progression-free survival with encorafenib plus binimetinib versus vemurafenib, was reported previously. Here we present the prespecified interim overall survival analysis. Efficacy analyses were by intent to treat. Safety was analysed in patients who received at least one dose of study drug. Part 2 of the study was initiated at the request of the US Food and Drug Administration to better understand the contribution of binimetinib to the combination therapy by comparing encorafenib 300 mg once daily plus binimetinib 45 mg twice daily with encorafenib 300 mg once daily alone. Results of part 2 will be published separately. This trial is ongoing and is registered with ClinicalTrials.gov, number NCT01909453, and EudraCT, number 2013-001176-38. FINDINGS: Between Dec 30, 2013, and April 10, 2015, 577 of 1345 screened patients were randomly assigned to receive encorafenib plus binimetinib (n=192), encorafenib (n=194), or vemurafenib (n=191). Median follow-up for overall survival was 36·8 months (95% CI 35·9-37·5). Median overall survival was 33·6 months (95% CI 24·4-39·2) with encorafenib plus binimetinib and 16·9 months (14·0-24·5) with vemurafenib (hazard ratio 0·61 [95% CI 0·47-0·79]; two-sided p<0·0001). The most common grade 3 or 4 adverse events did not change substantially from the first report; those seen in more than 5% of patients treated with encorafenib plus binimetinib were increased γ-glutamyltransferase (18 [9%] of 192 patients), increased blood creatine phosphokinase (14 [7%]), and hypertension (12 [6%]); those seen with encorafenib alone were palmar-plantar erythrodysaesthesia syndrome (26 [14%] of 192 patients), myalgia (19 [10%]), and arthralgia (18 [9%]); and with vemurafenib the most common grade 3 or 4 adverse event was arthralgia (11 [6%] of 186 patients). One death in the combination treatment group was considered by the investigator to be possibly related to treatment. INTERPRETATION: The combination of encorafenib plus binimetinib provided clinically meaningful efficacy with good tolerability as shown by improvements in both progression-free survival and overall survival compared with vemurafenib. These data suggest that the combination of encorafenib plus binimetinib is likely to become an important therapeutic option in patients with BRAFV600-mutant melanoma. FUNDING: Array BioPharma, Novartis.

[Postural tachycardia syndrome (PoTS): An up-to-date]. / Le syndrome de tachycardie posturale (PoTS) : une maladie pour l'interniste.

Postural tachycardia syndrome (PoTS) is a multifactorial syndrome defined by an increase in heart rate ≥30bpm, within 10minutes of standing (or during a head up tilt test to at least 60°), in absence of orthostatic hypotension. It is associated with symptoms of cerebral hypoperfusion that are worse when upright and improve in supine position. Patients have an intense fatigue with a high incidence on quality of life. This syndrome can be explained by many pathophysiological mechanisms. It can be associated with Ehlers-Danlos disease and some autoimmune disorders. The treatment is based on nonpharmacological measures and treatment with propranolol, fludrocortisone or midodrine.

Encorafenib plus binimetinib versus vemurafenib or encorafenib in patients with BRAF-mutant melanoma (COLUMBUS): a multicentre, open-label, randomised phase 3 trial.

BACKGROUND: Combined BRAF-MEK inhibitor therapy is the standard of care for BRAFV600-mutant advanced melanoma. We investigated encorafenib, a BRAF inhibitor with unique target-binding properties, alone or in combination with the MEK inhibitor binimetinib, versus vemurafenib in patients with advanced BRAFV600-mutant melanoma. METHODS: COLUMBUS was conducted as a two-part, randomised, open-label phase 3 study at 162 hospitals in 28 countries. Eligible patients were aged 18 years or older and had histologically confirmed locally advanced (American Joint Committee on Cancer [AJCC] stage IIIB, IIIC, or IV), unresectable or metastatic cutaneous melanoma, or unknown primary melanoma; a BRAFV600E or BRAFV600K mutation; an Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1; and were treatment naive or had progressed on or after previous first-line immunotherapy. In part 1 of the study, patients were randomly assigned (1:1:1) via interactive response technology to receive either oral encorafenib 450 mg once daily plus oral binimetinib 45 mg twice daily (encorafenib plus binimetinib group), oral encorafenib 300 mg once daily (encorafenib group), or oral vemurafenib 960 mg twice daily (vemurafenib group). The primary endpoint was progression-free survival by blinded independent central review for encorafenib plus binimetinib versus vemurafenib. Efficacy analyses were by intention-to-treat. Safety was analysed in patients who received at least one dose of study drug and one postbaseline safety assessment. The results of part 2 will be published separately. This study is registered with ClinicalTrials.gov, number NCT01909453, and EudraCT, number 2013-001176-38. FINDINGS: Between Dec 30, 2013, and April 10, 2015, 577 of 1345 screened patients were randomly assigned to either the encorafenib plus binimetinib group (n=192), the encorafenib group (n=194), or the vemurafenib group (n=191). With a median follow-up of 16·6 months (95% CI 14·8-16·9), median progression-free survival was 14·9 months (95% CI 11·0-18·5) in the encorafenib plus binimetinib group and 7·3 months (5·6-8·2) in the vemurafenib group (hazard ratio [HR] 0·54, 95% CI 0·41-0·71; two-sided p<0·0001). The most common grade 3-4 adverse events seen in more than 5% of patients in the encorafenib plus binimetinib group were increased γ-glutamyltransferase (18 [9%] of 192 patients), increased creatine phosphokinase (13 [7%]), and hypertension (11 [6%]); in the encorafenib group they were palmoplantar erythrodysaesthesia syndrome (26 [14%] of 192 patients), myalgia (19 [10%]), and arthralgia (18 [9%]); and in the vemurafenib group it was arthralgia (11 [6%] of 186 patients). There were no treatment-related deaths except for one death in the combination group, which was considered possibly related to treatment by the investigator. INTERPRETATION: Encorafenib plus binimetinib and encorafenib monotherapy showed favourable efficacy compared with vemurafenib. Overall, encorafenib plus binimetinib appears to have an improved tolerability profile compared with encorafenib or vemurafenib. Encorafenib plus binimetinib could represent a new treatment option for patients with BRAF-mutant melanoma. FUNDING: Array BioPharma, Novartis.

Corticosterone may interact with peripubertal development to shape adult resistance to social defeat.

Studies of social stress in adult mice have revealed two distinct defeat-responsive behavioral phenotypes; "susceptible" and "resistant," characterized by social avoidance and social interaction, respectively. Typically, these phenotypes are observed at least 1day after the last defeat in adults, but may extend up to 30days later. The current study examined the impact of peripubertal social defeat on immediate (1day) and adult (30day) social stress phenotypes and neuroendocrine function in male C57BL/6 mice. Initially, peripubertal (P32) mice were resistant to social defeat. When the same mice were tested for social interaction again as adults (P62), two phenotypes emerged; a group of mice were characterized as susceptible evidenced by significantly lower social interaction, whereas the remaining mice exhibited normal social interaction, characteristic of resistance. A repeated analysis of corticosterone revealed that the adult (P62) resistant mice had elevated corticosterone following the social interaction test as juveniles. This was when all mice, regardless of adult phenotype, displayed equivalent levels of social interaction. Peripubertal corticosterone was positively correlated with adult social interaction levels in defeated mice, suggesting early life stress responsiveness impacts adult social behavior. In addition, adult corticotropin-releasing factor (CRF) mRNA in the paraventricular nucleus of the hypothalamus (PVN) was elevated in all defeated mice, but there were no differences in CRF mRNA expression between the phenotypes. Thus, there is a delayed appearance of social stress-responsive phenotypes suggesting that early life stress exposure, combined with the resultant physiological responses, may interact with pubertal development to influence adult social behavior.

Stress-Induced Anxiety- and Depressive-Like Phenotype Associated with Transient Reduction in Neurogenesis in Adult Nestin-CreERT2/Diphtheria Toxin Fragment A Transgenic Mice.

Depression and anxiety involve hippocampal dysfunction, but the specific relationship between these mood disorders and adult hippocampal dentate gyrus neurogenesis remains unclear. In both humans with MDD and rodent models of depression, administration of antidepressants increases DG progenitor and granule cell number, yet rodents with induced ablation of DG neurogenesis typically do not demonstrate depressive- or anxiety-like behaviors. The conflicting data may be explained by the varied duration and degree to which adult neurogenesis is reduced in different rodent neurogenesis ablation models. In order to test this hypothesis we examined how a transient-rather than permanent-inducible reduction in neurogenesis would alter depressive- and anxiety-like behaviors. Transgenic Nestin-CreERT2/floxed diphtheria toxin fragment A (DTA) mice (Cre+DTA+) and littermates (Cre+DTA-; control) were given tamoxifen (TAM) to induce recombination and decrease nestin-expressing stem cells and their progeny. The decreased neurogenesis was transient: 12 days post-TAM Cre+DTA+ mice had fewer DG proliferating Ki67+ cells and fewer DCX+ neuroblasts/immature neurons relative to control, but 30 days post-TAM Cre+DTA+ mice had the same DCX+ cell number as control. This ability of DG neurogenesis to recover after partial ablation also correlated with changes in behavior. Relative to control, Cre+DTA+ mice tested between 12-30 days post-TAM displayed indices of a stress-induced anxiety phenotype-longer latency to consume highly palatable food in the unfamiliar cage in the novelty-induced hypophagia test, and a depression phenotype-longer time of immobility in the tail suspension test, but Cre+DTA+ mice tested after 30 days post-TAM did not. These findings suggest a functional association between adult neurogenesis and stress induced anxiety- and depressive-like behaviors, where induced reduction in DCX+ cells at the time of behavioral testing is coupled with stress-induced anxiety and a depressive phenotype, and recovery of DCX+ cell number corresponds to normalization of these behaviors.

Metabolic labeling with stable isotope nitrogen (15N) to follow amino acid and protein turnover of three plastid proteins in Chlamydomonas reinhardtii.

BACKGROUND: The length of time that a protein remains available to perform its function is significantly influenced by its turnover rate. Knowing the turnover rate of proteins involved in different processes is important to determining how long a function might progress even when the stimulus has been removed and no further synthesis of the particular proteins occurs. In this article, we describe the use of 15N-metabolic labeling coupled to GC-MS to follow the turnover of free amino acids and LC-MS/MS to identify and LC-MS to follow the turnover of specific proteins in Chlamydomonas reinhardtii. RESULTS: To achieve the metabolic labeling, the growth medium was formulated with standard Tris acetate phosphate medium (TAP) in which14NH4Cl was replaced with 15NH415NO3 and (14NH4)6Mo7O24.4H2O was replaced with Na2MoO4.2H2O. This medium designated 15N-TAP allowed CC-125 algal cells to grow normally. Mass isotopic distribution revealed successful 15N incorporation into 13 amino acids with approximately 98% labeling efficiency. Tryptic digestion of the 55 kDa SDS-PAGE bands from 14N- and 15N-labeled crude algal protein extracts followed by LC-MS/MS resulted in the identification of 27 proteins. Of these, five displayed peptide sequence confidence levels greater than 95% and protein sequence coverage greater than 25%. These proteins were the RuBisCo large subunit, ATP synthase CF1 alpha and beta subunits, the mitochondrial protein (F1F0 ATP synthase) and the cytosolic protein (S-adenosyl homocysteine hydroxylase). These proteins were present in both labeled and unlabeled samples. Once the newly synthesized 15N-labeled free amino acids and proteins obtained maximum incorporation of the 15N-label, turnover rates were determined after transfer of cells into 14N-TAP medium. The t½ values were determined for the three plastid proteins (RuBisCo, ATP synthase CF1 alpha and beta) by following the reduction of the 15N-fractional abundance over time. CONCLUSION: We describe a more rapid and non-radioactive method to measure free amino acid and protein turnover. Our approach is applicable for determination of protein turnover for various proteins, which will lead to a better understanding of the relationship between protein lifetime and functionality.

Paradoxical enhancement of fear expression and extinction deficits in mice resilient to social defeat.

The exposure to stress has been associated with increased depressive and anxiety symptoms, yet not all individuals respond negatively to the experience of stress. Recent rodent social defeat models demonstrate similar individual differences in response to social stress. In particular, mice subjected to chronic social defeat have been characterized as being either "susceptible" or "resilient" by the level of social interaction following social defeat. Susceptibility is associated with lasting social avoidance as well as increased anxiety-like behavior, and depressive-like symptoms. Resilient animals, however, do not show social avoidance or increased depressive-like symptoms, but retain increased anxiety-like behavior. Thus, it is unclear what "resilience" as measured by social interaction represents in terms of an overall behavioral and physiological phenotype. Here, we use an acute social defeat procedure, which produces distinct behavioral phenotypes in social interaction with no apparent changes in anxiety-like behavior. Susceptible mice display lasting social avoidance, whereas resilient mice display normal social interaction. Susceptible mice also displayed deficits in fear extinction retention but had normal within-session extinction. Paradoxically, resilience was associated with enhanced fear expression, and severe deficits in fear extinction and extinction retention beyond that observed in susceptible mice. These effects in resilient mice were only apparent after the experience of social stress and were not due to impaired behavioral flexibility. These data suggest that mechanisms controlling resilience to acute social defeat as characterized by social interaction leave animals vulnerable to maladaptive fear behavior.