Spatially coordinated heterochromatinization of long synaptic genes in fragile X syndrome.

Short tandem repeat (STR) instability causes transcriptional silencing in several repeat expansion disorders. In fragile X syndrome (FXS), mutation-length expansion of a CGG STR represses FMR1 via local DNA methylation. Here, we find megabase-scale H3K9me3 domains on autosomes and encompassing FMR1 on the X chromosome in FXS patient-derived iPSCs, iPSC-derived neural progenitors, EBV-transformed lymphoblasts, and brain tissue with mutation-length CGG expansion. H3K9me3 domains connect via inter-chromosomal interactions and demarcate severe misfolding of TADs and loops. They harbor long synaptic genes replicating at the end of S phase, replication-stress-induced double-strand breaks, and STRs prone to stepwise somatic instability. CRISPR engineering of the mutation-length CGG to premutation length reverses H3K9me3 on the X chromosome and multiple autosomes, refolds TADs, and restores gene expression. H3K9me3 domains can also arise in normal-length iPSCs created with perturbations linked to genome instability, suggesting their relevance beyond FXS. Our results reveal Mb-scale heterochromatinization and trans interactions among loci susceptible to instability.

Disease-Associated Short Tandem Repeats Co-localize with Chromatin Domain Boundaries.

More than 25 inherited human disorders are caused by the unstable expansion of repetitive DNA sequences termed short tandem repeats (STRs). A fundamental unresolved question is why some STRs are susceptible to pathologic expansion, whereas thousands of repeat tracts across the human genome are relatively stable. Here, we discover that nearly all disease-associated STRs (daSTRs) are located at boundaries demarcating 3D chromatin domains. We identify a subset of boundaries with markedly higher CpG island density compared to the rest of the genome. daSTRs specifically localize to ultra-high-density CpG island boundaries, suggesting they might be hotspots for epigenetic misregulation or topological disruption linked to STR expansion. Fragile X syndrome patients exhibit severe boundary disruption in a manner that correlates with local loss of CTCF occupancy and the degree of FMR1 silencing. Our data uncover higher-order chromatin architecture as a new dimension in understanding repeat expansion disorders.

Cohesin-mediated loop anchors confine the locations of human replication origins.

DNA replication occurs through an intricately regulated series of molecular events and is fundamental for genome stability1,2. At present, it is unknown how the locations of replication origins are determined in the human genome. Here we dissect the role of topologically associating domains (TADs)3-6, subTADs7 and loops8 in the positioning of replication initiation zones (IZs). We stratify TADs and subTADs by the presence of corner-dots indicative of loops and the orientation of CTCF motifs. We find that high-efficiency, early replicating IZs localize to boundaries between adjacent corner-dot TADs anchored by high-density arrays of divergently and convergently oriented CTCF motifs. By contrast, low-efficiency IZs localize to weaker dotless boundaries. Following ablation of cohesin-mediated loop extrusion during G1, high-efficiency IZs become diffuse and delocalized at boundaries with complex CTCF motif orientations. Moreover, G1 knockdown of the cohesin unloading factor WAPL results in gained long-range loops and narrowed localization of IZs at the same boundaries. Finally, targeted deletion or insertion of specific boundaries causes local replication timing shifts consistent with IZ loss or gain, respectively. Our data support a model in which cohesin-mediated loop extrusion and stalling at a subset of genetically encoded TAD and subTAD boundaries is an essential determinant of the locations of replication origins in human S phase.

HiCuT: An efficient and low input method to identify protein-directed chromatin interactions.

3D genome organization regulates gene expression, and disruption of these long-range (>20kB) DNA-protein interactions results in pathogenic phenotypes. Chromosome conformation methods in conjunction with chromatin immunoprecipitation were used to decipher protein-directed chromatin interactions. However, these methods required abundant starting material (>500,000 cells), sizable number of sequencing reads (>100 million reads), and elaborate data processing methods to reduce background noise, which limited their use in primary cells. Hi-C Coupled chromatin cleavage and Tagmentation (HiCuT) is a new transposase-assisted tagmentation method that generates high-resolution protein directed long-range chromatin interactions as efficiently as existing methods, HiChIP and ChIA-PET, despite using 100,000 cells (5-fold less) and 12 million sequencing reads (8-fold fewer). Moreover, HiCuT generates high resolution fragment libraries with low background signal that are easily interpreted with minimal computational processing. We used HiCuT in human primary skin cells to link previously identified single nucleotide polymorphisms (SNPs) in skin disease to candidate genes and to identify functionally relevant transcription factors in an unbiased manner. HiCuT broadens the capacity for genomic profiling in systems previously unmeasurable, including primary cells, human tissue samples, and rare cell populations, and may be a useful tool for all investigators studying human genetics and personalized epigenomics.

A Novel Creatinine Muscle Index Based on Creatinine Filtration: Associations with Frailty and Mortality.

SIGNIFICANCE STATEMENT: Low muscle mass is related to frailty and increased mortality in older adults. However, muscle mass is not easily assessed in routine clinical practice. This paper describes a novel creatinine muscle index (CMI) on the basis of serum creatinine and cystatin C. CMI was moderately associated with frailty among older adults. A significantly higher proportion of individuals with weak grip strength were in the lowest tertile of CMI. The index was also associated with mortality. These results are consistent with the hypothesis that creatinine filtration may be an index of muscle mass, which may have utility in clinical practice. BACKGROUND: Low muscle mass is related to frailty and increased mortality in older adults. However, muscle mass is not easily assessed in routine clinical practice. METHODS: This study describes a novel creatinine muscle index (CMI) on the basis of serum creatinine and cystatin C in a community-based sample of older adults from the Atherosclerosis Risk in Communities Study. Analyses included 4639 participants who attended visit 5 (2011-2013) and 12,786 participants who attended visit 2 (1990-1992). CMI was defined as creatinine filtration (the product of serum creatinine times eGFR on the basis of cystatin C) and was analyzed in sex-specific tertiles. Cross-sectional associations of CMI with a frailty trichotomy, defined by the number (robust [0]/prefrail [1-2]/frail [3-5]) of five frailty components (weight loss, slowness, exhaustion, weakness, and low physical activity), were studied using polychotomous logistic regression and binary logistic regression with each frailty component. Cox regression was used to estimate associations of CMI at visit 5 and visit 2 with mortality. Models were adjusted for demographics, clinical variables, and comorbid conditions. RESULTS: CMI (tertile 1 versus 3) was moderately associated with frailty (visit 5: adjusted odds ratio 4.23 [95% confidence interval (CI), 2.02 to 8.87] in men and 2.34 [95% CI, 1.41 to 3.89] in women) and with mortality (visit 5: adjusted hazard ratio 1.45 [95% CI, 1.08 to 1.94] in men and 1.55 [95% CI, 1.13 to 2.12] in women; similar results were seen at visit 2). CONCLUSION: Lower CMI was associated with frailty and increased mortality, two clinical outcomes known to be associated with decreased muscle mass. Creatinine filtration may be an index of muscle mass and have utility in clinical practice, particularly at low levels.

Alterations in the Circulating Proteome Associated with Albuminuria.

SIGNIFICANCE STATEMENT: We describe circulating proteins associated with albuminuria in a population of African American Study of Kidney Disease and Hypertension with CKD (AASK) using the largest proteomic platform to date: nearly 7000 circulating proteins, representing approximately 2000 new targets. Findings were replicated in a subset of a general population cohort with kidney disease (ARIC) and a population with CKD Chronic Renal Insufficiency Cohort (CRIC). In cross-sectional analysis, 104 proteins were significantly associated with albuminuria in the Black group, of which 67 of 77 available proteins were replicated in ARIC and 68 of 71 available proteins in CRIC. LMAN2, TNFSFR1B, and members of the ephrin superfamily had the strongest associations. Pathway analysis also demonstrated enrichment of ephrin family proteins. BACKGROUND: Proteomic techniques have facilitated understanding of pathways that mediate decline in GFR. Albuminuria is a key component of CKD diagnosis, staging, and prognosis but has been less studied than GFR. We sought to investigate circulating proteins associated with higher albuminuria. METHODS: We evaluated the cross-sectional associations of the blood proteome with albuminuria and longitudinally with doubling of albuminuria in the African American Study of Kidney Disease and Hypertension (AASK; 38% female; mean GFR 46; median urine protein-to-creatinine ratio 81 mg/g; n =703) and replicated in two external cohorts: a subset of the Atherosclerosis Risk in Communities (ARIC) study with CKD and the Chronic Renal Insufficiency Cohort (CRIC). RESULTS: In cross-sectional analysis, 104 proteins were significantly associated with albuminuria in AASK, of which 67 of 77 available proteins were replicated in ARIC and 68 of 71 available proteins in CRIC. Proteins with the strongest associations included LMAN2, TNFSFR1B, and members of the ephrin superfamily. Pathway analysis also demonstrated enrichment of ephrin family proteins. Five proteins were significantly associated with worsening albuminuria in AASK, including LMAN2 and EFNA4, which were replicated in ARIC and CRIC. CONCLUSIONS: Among individuals with CKD, large-scale proteomic analysis identified known and novel proteins associated with albuminuria and suggested a role for ephrin signaling in albuminuria progression.

Testican-2 Is Associated with Reduced Risk of Incident ESKD.

BACKGROUND: Testican-2 was recently identified as a podocyte-derived protein that is released into circulation by the kidneys and is positively correlated with eGFR and eGFR slope. However, whether higher testican-2 levels are associated with lower risk of ESKD is unknown. METHODS: Aptamer-based proteomics assessed blood testican-2 levels among participants in the African American Study of Kidney Disease and Hypertension (AASK, n =703), the Chronic Renal Insufficiency Cohort (CRIC) study ( n =3196), and the Atherosclerosis Risk in Communities (ARIC) study ( n =4378). We compared baseline characteristics by testican-2 tertile and used Cox proportional hazards models to study the association of testican-2 with incident ESKD. RESULTS: Higher testican-2 levels were associated with higher measured GFR (mGFR) in AASK, higher eGFR in the CRIC and ARIC studies, and lower albuminuria in all cohorts. Baseline testican-2 levels were significantly associated with incident ESKD in Cox proportional hazards models adjusted for age, sex, and race (model 1) and model 1+mGFR or eGFR+comorbidities (model 2). In model 3 (model 2+proteinuria), the associations between testican-2 (per SD increase) and incident ESKD were AASK (hazard ratio [HR]=0.84 [0.72 to 0.98], P =0.023), CRIC (HR=0.95 [0.89 to 1.02], P =0.14), ARIC (HR=0.54 [0.36 to 0.83], P =0.0044), and meta-analysis (HR=0.92 [0.86 to 0.98], P =0.0073). CONCLUSIONS: Across three cohorts spanning >8000 individuals, testican-2 is associated with kidney health and prognosis, with higher levels associated with reduced risk of ESKD.

Integrated proteomic and metabolomic modules identified as biomarkers of mortality in the Atherosclerosis Risk in Communities study and the African American Study of Kidney Disease and Hypertension.

BACKGROUND: Proteins and metabolites are essential for many biological functions and often linked through enzymatic or transport reactions. Individual molecules have been associated with all-cause mortality. Many of these are correlated and might jointly represent pathways or endophenotypes involved in diseases. RESULTS: We present an integrated analysis of proteomics and metabolomics via a local dimensionality reduction clustering method. We identified 224 modules of correlated proteins and metabolites in the Atherosclerosis Risk in Communities (ARIC) study, a general population cohort of older adults (N = 4046, mean age 75.7, mean eGFR 65). Many of the modules displayed strong cross-sectional associations with demographic and clinical characteristics. In comprehensively adjusted analyses, including fasting plasma glucose, history of cardiovascular disease, systolic blood pressure and kidney function among others, 60 modules were associated with mortality. We transferred the network structure to the African American Study of Kidney Disease and Hypertension (AASK) (N = 694, mean age 54.5, mean mGFR 46) and identified mortality associated modules relevant in this disease specific cohort. The four mortality modules relevant in both the general population and CKD were all a combination of proteins and metabolites and were related to diabetes / insulin secretion, cardiovascular disease and kidney function. Key components of these modules included N-terminal (NT)-pro hormone BNP (NT-proBNP), Sushi, Von Willebrand Factor Type A, EGF And Pentraxin (SVEP1), and several kallikrein proteases. CONCLUSION: Through integrated biomarkers of the proteome and metabolome we identified functions of (patho-) physiologic importance related to diabetes, cardiovascular disease and kidney function.

Identification of 969 protein quantitative trait loci in an African American population with kidney disease attributed to hypertension.

Investigations into the causal underpinnings of disease processes can be aided by the incorporation of genetic information. Genetic studies require populations varied in both ancestry and prevalent disease in order to optimize discovery and ensure generalizability of findings to the global population. Here, we report the genetic determinants of the serum proteome in 466 African Americans with chronic kidney disease attributed to hypertension from the richly phenotyped African American Study of Kidney Disease and Hypertension (AASK) study. Using the largest aptamer-based protein profiling platform to date (6,790 proteins or protein complexes), we identified 969 genetic associations with 900 unique proteins; including 52 novel cis (local) associations and 379 novel trans (distant) associations. The genetic effects of previously published cis-protein quantitative trait loci (pQTLs) were found to be highly reproducible, and we found evidence that our novel genetic signals colocalize with gene expression and disease processes. Many trans- pQTLs were found to reflect associations mediated by the circulating cis protein, and the common trans-pQTLs are enriched for processes involving extracellular vesicles, highlighting a plausible mechanism for distal regulation of the levels of secreted proteins. Thus, our study generates a valuable resource of genetic associations linking variants to protein levels and disease in an understudied patient population to inform future studies of drug targets and physiology.

Trans-ethnic genome-wide association study of blood metabolites in the Chronic Renal Insufficiency Cohort (CRIC) study.

Metabolomics genome wide association study (GWAS) help outline the genetic contribution to human metabolism. However, studies to date have focused on relatively healthy, population-based samples of White individuals. Here, we conducted a GWAS of 537 blood metabolites measured in the Chronic Renal Insufficiency Cohort (CRIC) Study, with separate analyses in 822 White and 687 Black study participants. Trans-ethnic meta-analysis was then applied to improve fine-mapping of potential causal variants. Mean estimated glomerular filtration rate was 44.4 and 41.5 mL/min/1.73m2 in the White and Black participants, respectively. There were 45 significant metabolite associations at 19 loci, including novel associations at PYROXD2, PHYHD1, FADS1-3, ACOT2, MYRF, FAAH, and LIPC. The strength of associations was unchanged in models additionally adjusted for estimated glomerular filtration rate and proteinuria, consistent with a direct biochemical effect of gene products on associated metabolites. At several loci, trans-ethnic meta-analysis, which leverages differences in linkage disequilibrium across populations, reduced the number and/or genomic interval spanned by potentially causal single nucleotide polymorphisms compared to fine-mapping in the White participant cohort alone. Across all validated associations, we found strong concordance in effect sizes of the potentially causal single nucleotide polymorphisms between White and Black study participants. Thus, our study identifies novel genetic determinants of blood metabolites in chronic kidney disease, demonstrates the value of diverse cohorts to improve causal inference in metabolomics GWAS, and underscores the shared genetic basis of metabolism across race.

Polygenic Risk Scores for Kidney Function and Their Associations with Circulating Proteome, and Incident Kidney Diseases.

BACKGROUND: Genome-wide association studies (GWAS) have revealed numerous loci for kidney function (eGFR). The relationship between polygenic predictors of eGFR, risk of incident adverse kidney outcomes, and the plasma proteome is not known. METHODS: We developed a genome-wide polygenic risk score (PRS) for eGFR by applying the LDpred algorithm to summary statistics generated from a multiethnic meta-analysis of CKDGen Consortium GWAS ( n =765,348) and UK Biobank GWAS (90% of the cohort; n =451,508), followed by best-parameter selection using the remaining 10% of UK Biobank data ( n =45,158). We then tested the association of the PRS in the Atherosclerosis Risk in Communities (ARIC) study ( n =8866) with incident CKD, ESKD, kidney failure, and AKI. We also examined associations between the PRS and 4877 plasma proteins measured at middle age and older adulthood and evaluated mediation of PRS associations by eGFR. RESULTS: The developed PRS showed a significant association with all outcomes. Hazard ratios per 1 SD lower PRS ranged from 1.06 (95% CI, 1.01 to 1.11) to 1.33 (95% CI, 1.28 to 1.37). The PRS was significantly associated with 132 proteins at both time points. The strongest associations were with cystatin C, collagen α -1(XV) chain, and desmocollin-2. Most proteins were higher at lower kidney function, except for five proteins, including testican-2. Most correlations of the genetic PRS with proteins were mediated by eGFR. CONCLUSIONS: A PRS for eGFR is now sufficiently strong to capture risk for a spectrum of incident kidney diseases and broadly influences the plasma proteome, primarily mediated by eGFR.

Proteins Associated with Risk of Kidney Function Decline in the General Population.

BACKGROUND: Proteomic profiling may allow identification of plasma proteins that associate with subsequent changesin kidney function, elucidating biologic processes underlying the development and progression of CKD. METHODS: We quantified the association between 4877 plasma proteins and a composite outcome of ESKD or decline in eGFR by ≥50% among 9406 participants in the Atherosclerosis Risk in Communities (ARIC) Study (visit 3; mean age, 60 years) who were followed for a median of 14.4 years. We performed separate analyses for these proteins in a subset of 4378 participants (visit 5), who were followed at a later time point, for a median of 4.4 years. For validation, we evaluated proteins with significant associations (false discovery rate <5%) in both time periods in 3249 participants in the Chronic Renal Insufficiency Cohort (CRIC) and 703 participants in the African American Study of Kidney Disease and Hypertension (AASK). We also compared the genetic determinants of protein levels with those from a meta-analysis genome-wide association study of eGFR. RESULTS: In models adjusted for multiple covariates, including baseline eGFR and albuminuria, we identified 13 distinct proteins that were significantly associated with the composite end point in both time periods, including TNF receptor superfamily members 1A and 1B, trefoil factor 3, and ß-trace protein. Of these proteins, 12 were also significantly associated in CRIC, and nine were significantly associated in AASK. Higher levels of each protein associated with higher risk of 50% eGFR decline or ESKD. We found genetic evidence for a causal role for one protein, lectin mannose-binding 2 protein (LMAN2). CONCLUSIONS: Large-scale proteomic analysis identified both known and novel proteomic risk factors for eGFR decline.

Combined Use of PGPRs and Reduced Rates of Azoxystrobin to Improve Management of Sheath Blight of Rice.

Farmers rely heavily on the use of strobilurin fungicides to manage sheath blight (ShB) caused by Rhizoctonia solani AG1-IA, the most important disease in rice in the southern United States. Greenhouse and field studies were conducted to evaluate the potential use of plant growth-promoting rhizobacteria (PGPRs) in combination with a reduced rate of azoxystrobin application as a strategy to improve the current fungicide-reliant management. Of the nine antagonistic PGPR strains screened in the greenhouse, Bacillus subtilis strain MBI600 provided the most significant and consistent suppression of ShB. Efficacy of strain MBI600 was further evaluated at the concentrations of 0, 103, 106, 109, and 1011 CFU/ml alone or in combinations with 0, 17, 33, 50, 67, 83, and 100% of the recommended application rate (0.16 kg a.i./ha) of azoxystrobin. Strain MBI600 applied at 106,109, and 1011 CFU/ml alone was effective in reducing ShB severity. Combinations of this strain at these rates with ≥33% of the recommended application rate of azoxystrobin further reduced ShB severity. A dose-response model defining the relationships between strain MBI600, azoxystrobin, and ShB severity was established. Estimates of the effective concentrations (EC50 and EC90) of strain MBI600 when applied in combination with 50% of the recommended application rate of azoxystrobin were 104 and 109 CFU/ml, respectively. A field trial was conducted over 4 years to verify the efficacy of their combinations. Strain MBI600 alone, when applied at 109 CFU/ml at the boot stage, reduced ShB severity but did not significantly increase grain yields each year. Combination of strain MBI600 with azoxystrobin at half of the recommended application rate improved efficacy of strain MBI600, reducing ShB severity to a level comparable to that of azoxystrobin applied at the full rate in all 4 years. The combined treatment also increased grain yield by 14 to 19%, comparable to the fungicide applied at the full rate in 3 of 4 years. Combined use of PGPR strain MBI600 with a reduced rate of azoxystrobin application can be a viable management option for control of ShB while allowing producers to use less fungicide on rice.

YY1 and CTCF orchestrate a 3D chromatin looping switch during early neural lineage commitment.

CTCF is an architectural protein with a critical role in connecting higher-order chromatin folding in pluripotent stem cells. Recent reports have suggested that CTCF binding is more dynamic during development than previously appreciated. Here, we set out to understand the extent to which shifts in genome-wide CTCF occupancy contribute to the 3D reconfiguration of fine-scale chromatin folding during early neural lineage commitment. Unexpectedly, we observe a sharp decrease in CTCF occupancy during the transition from naïve/primed pluripotency to multipotent primary neural progenitor cells (NPCs). Many pluripotency gene-enhancer interactions are anchored by CTCF, and its occupancy is lost in parallel with loop decommissioning during differentiation. Conversely, CTCF binding sites in NPCs are largely preexisting in pluripotent stem cells. Only a small number of CTCF sites arise de novo in NPCs. We identify another zinc finger protein, Yin Yang 1 (YY1), at the base of looping interactions between NPC-specific genes and enhancers. Putative NPC-specific enhancers exhibit strong YY1 signal when engaged in 3D contacts and negligible YY1 signal when not in loops. Moreover, siRNA knockdown of Yy1 specifically disrupts interactions between key NPC enhancers and their target genes. YY1-mediated interactions between NPC regulatory elements are often nested within constitutive loops anchored by CTCF. Together, our results support a model in which YY1 acts as an architectural protein to connect developmentally regulated looping interactions; the location of YY1-mediated interactions may be demarcated in development by a preexisting topological framework created by constitutive CTCF-mediated interactions.

Efficacy and Safety of Apremilast Monotherapy for Moderate to Severe Psoriasis: Retrospective Study.

BACKGROUND: Apremilast is a new oral drug for the treatment of moderate to severe plaque psoriasis that reduces inflammation by inhibiting phosphodiesterase 4. Its efficacy and safety data are limited; hence, real-world outcomes are important for elucidating the full spectrum of its adverse events (AEs) and expanding generalizability of clinical trial findings. OBJECTIVE: Assess the efficacy and safety of apremilast monotherapy in real-world practice. METHODS: A retrospective chart review was conducted in 2 academic dermatology practices. Efficacy was measured as the proportion of patients achieving a ≥75% reduction from baseline Psoriasis Area and Severity Index score (PASI-75) or a Psoriasis Global Assessment (PGA) score of 0 (clear) or 1 (almost clear) at 16 weeks. Safety was measured as the proportion of patients reporting ≥1 AE at 16 weeks. RESULTS: Thirty-four patients were included. EFFICACY: 19 patients (55.9%) achieved PASI-75 or PGA 0/1. SAFETY: 23 patients (67.6%) experienced ≥1 AEs. Five patients (14.7%) withdrew treatment prior to week 16 due to AEs. One patient withdrew treatment due to mood lability and depression. Common AEs included headache (32.4%), nausea (20.6%), diarrhoea (14.7%), weight loss (8.8%), and loose stool (8.8%). CONCLUSION: Apremilast monotherapy had higher efficacy with similar safety outcomes in the real world compared to clinical trials. There were higher proportions of reported headaches compared to clinical trials. This study supports the apremilast monotherapy clinical trial findings, suggesting that it has an acceptable safety profile and significantly reduces the severity of moderate to severe plaque psoriasis. Limitations include the retrospective nature of the study.

Drug-associated skin lesions in a patient with myelofibrosis receiving ruxolitinib.

Ruxolitinib, a small molecule JAK-1/2 inhibitor, was approved by the U.S. Food and Drug Administration (FDA) in November 2011, as the first therapeutic for the treatment of intermediate and high-risk myelofibrosis. The Janus kinase/signal transducers and activators of transcription (JAK/STAT) pathway is one of the most well-studied intracellular signaling networks. Recent advances in our understanding of the complexities of signal activation and regulation of gene expression has provided opportunities for targeted therapeutic interventions. Although numerous inhibitors of the JAK/STAT pathway are currently being evaluated in clinical trials, ruxolitinib represents the first FDA approved in-class JAK inhibitor. We report a drug eruption associated with ruxolitinib.

A qualitative study of Canadian resident experiences with Competency-Based Medical Education.

Background: Competency-based medical education (CBME) is an outcomes-based curricular paradigm focused on ensuring that graduates are competent to meet the needs of patients. Although resident engagement is key to CBME's success, few studies have explored how trainees have experienced CBME implementation. We explored the experiences of residents in Canadian training programs that had implemented CBME. Methods: We conducted semi-structured interviews with 16 residents in seven Canadian postgraduate training programs, exploring their experiences with CBME. Participants were equally divided between family medicine and specialty programs. Themes were identified using principles of constructivist grounded theory. Results: Residents were receptive to the goals of CBME, but in practice, described several drawbacks primarily related to assessment and feedback. For many residents, the significant administrative burden and focus on assessment led to performance anxiety. At times, residents felt that assessments lacked meaning as supervisors focused on "checking-boxes" or provided overly broad, non-specific comments. Furthermore, they commonly expressed frustration with the perceived subjectivity and inconsistency of judgments on assessments, especially if assessments were used to delay progression to greater independence, contributing to attempts to "game the system." Faculty engagement and support improved resident experiences with CBME. Conclusion: Although residents value the potential for CBME to improve the quality of education, assessment and feedback, the current operationalization of CBME may not be consistently achieving these objectives. The authors suggest several initiatives to improve how residents experience assessment and feedback processes in CBME.

Contexte: La formation médicale axée sur les compétences (FMFC) est un paradigme d'apprentissage axé sur les résultats et visant à garantir que les diplômés aient les compétences nécessaires pour répondre aux besoins des patients. Bien que l'engagement des résidents soit la clé du succès de la FMFC, peu d'études ont exploré comment ils vivent son introduction. Nous nous sommes penchés sur l'expérience des résidents dans les programmes de formation canadiens qui ont mis en œuvre la FMFC. Méthodes: Nous avons mené des entrevues semi-structurées avec 16 résidents de sept programmes de formation postdoctorale canadiens, afin de sonder leur expérience de la FMFC. Les participants provenaient de façon égale de la médecine familiale et de programmes de spécialité. Les thèmes ont été dégagés en appliquant les principes de la théorie enracinée constructiviste. Résultats: Bien que réceptifs aux objectifs de la FMFC, les résidents décrivent des inconvénients de sa mise en pratique, notamment sur le plan de l'évaluation et de la rétroaction. Pour beaucoup d'entre eux, la focalisation sur l'évaluation et le fardeau administratif qui y est lié ont été une source d'anxiété de performance. Les résidents ont l'impression que les évaluations manquent parfois de pertinence, car les superviseurs, se sentant contraints de « cocher des cases ¼, font des commentaires trop généraux et peu ciblés. De plus, un sentiment de frustration a été fréquemment exprimé face à la subjectivité et à l'incohérence perçues des jugements dans les évaluations, surtout lorsque ces dernières sont utilisées pour retarder le cheminement vers une plus grande indépendance, ce qui contribue à des tentatives de « déjouer le système ¼. L'implication et le soutien du corps professoral ont aidé à bonifier l'expérience des résidents. Conclusion: Bien que les résidents apprécient le potentiel de la FMFC pour rehausser la qualité de la formation, de l'évaluation et de la rétroaction, son opérationnalisation actuelle ne permet pas d'atteindre ces objectifs de façon systématique. Les auteurs proposent quelques initiatives pour améliorer la façon dont les résidents vivent les processus d'évaluation et de rétroaction dans le cadre de la FMFC.

Objective estimation of fusional reserves using infrared eye tracking: the digital fusion-range test.

CLINICAL RELEVANCE: Horizontal fusional reserves are used in the diagnosis and monitoring of common vergence disorders, such as convergence insufficiency, which can cause asthenopia and impact near work. Infrared eyetracking technology shows promise for obtaining automated and objective measurements of fusional reserves, expanding options for screening, clinical testing, and at-home monitoring/vision training. BACKGROUND: Current clinical tests for fusional reserves rely on subjective judgements made by patients (for diplopia) and clinicians (for eye movements). This paper describes an objective and automated "digital fusion-range test" pilot-tested in adults without current eye disease or binocular vision anomalies. This test combines a consumer-grade infrared eyetracker, a dichoptic display, and custom analyses programs to measure convergence and divergence reserves. METHODS: Twenty-nine adult participants completed the study. Horizontal fusional reserves at 55 cm were measured using prism bars and with our computer-based digital fusion-range test. For the digital test, observers viewed dichoptic targets whose binocular disparity modulated over time (at speeds of 0.5, 1.0, or 2.0 Δ/s) while their eye movements were continuously recorded. Subjective reports of break and recovery (by keyboard button press) were compared to objective estimates extracted from eyetracking recordings (via automated analyses). RESULTS: Objective and subjective measures of break and recovery agreed closely. Clinically small (0.3-2Δ) but statistically significant (p < 0.012) differences were found between measurement types for divergence breaks/recoveries and convergence recoveries. No significant differences were found for convergence breaks (p = 0.11). Such differences are consistent with an average 0.91 (SD 1.66) seconds delay between objective break/recovery and subjective responses. The digital test produced comparable results to the standard clinical prism bar method. CONCLUSION: The digital fusion-range test supports an automated, reliable assessment of horizontal fusional reserves, which do not depend on subjective responses. This technology may prove useful in a variety of clinical and community-based settings.

Proteomics analysis of plasma from middle-aged adults identifies protein markers of dementia risk in later life.

A diverse set of biological processes have been implicated in the pathophysiology of Alzheimer's disease (AD) and related dementias. However, there is limited understanding of the peripheral biological mechanisms relevant in the earliest phases of the disease. Here, we used a large-scale proteomics platform to examine the association of 4877 plasma proteins with 25-year dementia risk in 10,981 middle-aged adults. We found 32 dementia-associated plasma proteins that were involved in proteostasis, immunity, synaptic function, and extracellular matrix organization. We then replicated the association between 15 of these proteins and clinically relevant neurocognitive outcomes in two independent cohorts. We demonstrated that 12 of these 32 dementia-associated proteins were associated with cerebrospinal fluid (CSF) biomarkers of AD, neurodegeneration, or neuroinflammation. We found that eight of these candidate protein markers were abnormally expressed in human postmortem brain tissue from patients with AD, although some of the proteins that were most strongly associated with dementia risk, such as GDF15, were not detected in these brain tissue samples. Using network analyses, we found a protein signature for dementia risk that was characterized by dysregulation of specific immune and proteostasis/autophagy pathways in adults in midlife ~20 years before dementia onset, as well as abnormal coagulation and complement signaling ~10 years before dementia onset. Bidirectional two-sample Mendelian randomization genetically validated nine of our candidate proteins as markers of AD in midlife and inferred causality of SERPINA3 in AD pathogenesis. Last, we prioritized a set of candidate markers for AD and dementia risk prediction in midlife.