We consider the performance of the difference-in-means estimator in a two-arm randomized experiment under common experimental endpoints such as continuous (regression), incidence, proportion and survival. We examine performance under both equal and unequal allocation to treatment groups and we consider both the Neyman randomization model and the population model. We show that in the Neyman model, where the only source of randomness is the treatment manipulation, there is no free lunch: complete randomization is minimax for the estimator's mean squared error. In the population model, where each subject experiences response noise with zero mean, the optimal design is the deterministic perfect-balance allocation. However, this allocation is generally NP-hard to compute and moreover, depends on unknown response parameters. When considering the tail criterion of Kapelner et al. (2021), we show the optimal design is less random than complete randomization and more random than the deterministic perfect-balance allocation. We prove that Fisher's blocking design provides the asymptotically optimal degree of experimental randomness. Theoretical results are supported by simulations in all considered experimental settings.

We study randomized experiments with binary outcomes under Neyman's nonparametric model, where covariate measurements are fixed but potential outcomes are random. In this setting we derive the exact variance of the difference-in-means estimator and characterize designs that minimize it. We show that any balanced design satisfying a covariate-balance condition is asymptotically optimal, and we prove that a broad class of blocking designs satisfies this condition under mild smoothness assumptions. Because the variance depends on unknown success probabilities, unbiased variance estimation is impossible. We therefore develop two conservative estimators: a generalization of the Cochran-Mantel-Haenszel (CMH) statistic applicable to any balanced design, and an extension of Robins' variance estimator for blocking designs. We establish conditions under which the CMH-based estimator is asymptotically tight under local alternatives, thereby yielding asymptotically valid confidence intervals. Our theoretical and simulations results show that blocking and other designs that achieve covariate balance and sufficient degree of randomness, perform well when they are equipped with the CMH-based inference. Thus, we provide an experimental design and inference framework for incidence outcomes that is simultaneously variance-optimal, conservative in finite samples and asymptotically tight.

We consider the asymptotic power performance under local alternatives of the Cochran-Mantel-Haenszel test. Our setting is non-traditional: we investigate randomized experiments that assign subjects via Fisher's blocking design. We show that blocking designs that satisfy a certain balance condition are asymptotically optimal. When the potential outcomes can be ordered, the balance condition is met for all blocking designs with number of blocks going to infinity. More generally, we prove that the pairwise matching design of Greevy et al. (2004) satisfies the balance condition under mild assumptions. In smaller sample sizes, we show a second order effect becomes operational thereby making blocking designs with a smaller number optimal. In practical settings with many covariates, we recommend pairwise matching for its ability to approximate the balance condition.

Research on caregivers suggests interpersonal contact with persons with Alzheimer's disease (AD) and higher disease-oriented knowledge may heighten AD stigma, though these same mechanisms are often employed in anti-stigma campaigns. If we better understand associations among caregiver experience, interpersonal contact, AD knowledge and AD stigma, we can develop improved ways of reducing stigma and avoid unintended consequences. In a factorial design experiment, 2,371 participants read a vignette describing a fictional person; the vignette varied on clinical symptom stage, AD biomarker result, and treatment availability. Multivariable analyses assessed effects of caregiver experience, interpersonal contact, and different domains of disease-oriented knowledge on modified Family Stigma in Alzheimer's Disease Scale (FS-ADS) outcomes. Interaction analyses tested how clinical features may modify those associations. AD caregiver experience was associated with higher reactions on 6 of 7 FS-ADS domains. Disease-oriented knowledge, independent of content domain, did not substantially affect those associations. However, knowledge of caregiving, treatment, and life impact associated with lower FS-ADS scores, and knowledge about disease course and risk factors associated with higher reactions on FS-ADS domains. Knowledge of treatment modified reactions to symptoms and treatment availability. Knowledge of disease course modified reactions to a biomarker result. AD caregiver experience and interpersonal contact did not modify associations between clinical characteristics and FS-ADS domains. Distinct associations among different domains of AD knowledge and stigma outcomes should be considered when developing anti-stigma campaigns. Failure to do so risks worsening rather than alleviating AD stigma.

Endometrial and ovarian cancers are among the most common gynecologic malignancies in the U.S., with 5-year overall survival rates of 81% and 50% respectively. Ovarian cancer often presents late due to asymptomatic early stages and nonspecific symptoms in advanced stages. Few markers exist for early detection, and they lack the sensitivity and specificity needed for high-risk screening. Given the absence of informative protein blood biomarkers, cell-free DNA analysis has become a promising tool for early detection, treatment evaluation, and monitoring. However, previous studies of circulating tumor DNA (ctDNA) in gynecological cancers had limited sensitivity. We adapted MASQ (Multiplex Accurate Sensitive Quantitation), originally developed to measure residual cells in leukemia, to the measurement of ctDNA in solid cancers. MASQ detects patient-specific mutations simultaneously in up to 50 loci with exceptional sensitivity, below one part per million. This study uses MASQ to measure tumor-specific variants in blood (cell-free DNA) from endometrial and ovarian cancer patients, aiming to determine the range of ctDNA signals at presentation and explore correlations with clinicopathological features and patient outcomes. We analyzed samples from 46 gynecologic cancer patients (12 ovarian, 34 endometrial) treated at Northwell Health. Samples were collected in collaboration with gynecologic oncology research coordinators and the Northwell Health Biorepository. Peripheral blood was collected at diagnosis (n=46) and post-surgery (n=14), along with surgical tumor specimens. Whole genome sequencing of tumor and blood identified thousands of somatic tumor variants per patient. For each patient, 30 representative variants were selected for MASQ sequencing. MASQ libraries were generated from cell-free DNA isolated from pre- and post-surgery plasma. Ultrasensitive variant counts across 30 loci were aggregated and analyzed for clinical correlations. ctDNA signal was detected in 35 of 46 cases at presentation, with variant allele frequencies ranging from below 10^-4 to 10^-1. ctDNA signal was higher in ovarian cancer (13/13 detected) than endometrial cancer, and higher in aggressive Type II endometrial cancer (15/16) vs. Type I (5/13). ctDNA levels correlated with tumor size and copy number imbalance, but not with total cell-free DNA. Detection of ctDNA predicted worse overall survival (p=0.023) and was the strongest predictor of survival in multivariate analysis. Post-surgery follow-up in 10 of 14 patients showed significant ctDNA reduction following treatment, highlighting MASQ’s sensitivity in tracking treatment response. This study highlights the potential of sensitive ctDNA detection for early diagnosis and monitoring in gynecologic cancers. However, limited cell-free DNA abundance necessitates even more sensitive methods to enhance clinical utility. Andrea B. Moffitt, Jude Kendall, Joan Alexander, Asya Stepansky, Arisa Kapedani, Zihua Wang, Dan Levy, Kenny Ye, Abba M. Krieger, Marina Frimer, Gary L. Goldberg, Michael Wigler. Personalized detection of circulating cell-free tumor DNA in gynecologic cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 1 (Regular Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_1):Abstract nr 5890.

Objective.New implantable and wearable devices hold great promise to help patients manage their seizure disorders. One proposed application is measuring the rate of interictal epileptiform discharges as a biomarker of medication levels and seizure risk. This study aims to determine whether interictal epileptiform spike rates (spikes) are independently associated with anti-seizure medication (ASM) levels and evaluate whether spike rates are a reliable biomarker for ASM levels.Approach.We conducted a retrospective analysis of 69 patients with drug resistant epilepsy undergoing intracranial EEG monitoring during ASM taper in the epilepsy monitoring unit. An automated spike detection algorithm, validated seizure annotations, and a model of ASM load were used to assess the relationship between spike rates, ASM level, state of consciousness, and seizure timing using linear mixed effects models. Event related analysis and seasonal autoregressive models were applied to evaluate both short-term and longer-term effects of ASMs on spike rates, respectively.Main Results.Spike rates were found to increase following seizures, during sleep, and in patients experiencing early seizures, with no significant association between ASM load and spike rates after controlling for these confounders. Initial models without controls showed a positive association between ASM load and spike rates. However, this relationship disappeared when the effects of sleep and seizures were accounted for. Medication-specific analysis revealed that only levetiracetam showed a significant impact on spike rates during taper.Significance.This study demonstrates that interictal spike rates are more strongly influenced by seizure activity and sleep than by ASM levels, suggesting limited utility of spike rates as a biomarker for ASM load. However, spikes may still serve as important markers for seizure control and disease severity.

We consider the general performance of the difference-in-means estimator in an equally-allocated two-arm randomized experiment under common experimental endpoints such as continuous (regression), incidence, proportion, count and uncensored survival. We consider two sources of randomness: the subject-specific assignments and the contribution of unobserved subject-specific measurements. We then examine mean squared error (MSE) performance under a new, more realistic "simultaneous tail criterion". We prove that the pairwise matching design of Greevy et al. (2004) performs best asymptotically under this criterion when compared to other blocking designs. We also prove that the optimal design must be less random than complete randomization and more random than any deterministic, optimized allocation. Theoretical results are supported by simulations in all five response types.

We consider the problem of evaluating designs for a small-sample two-arm randomized experiment using the power of the one-sided randomization test as a criterion. Our evaluation assumes a linear response in one observed covariate, an unobserved component and an additive treatment effect where the model's randomness is due to different treatment allocations. It is well-known that the power depends on the allocations’ imbalance in the observed covariate. We show that power is additionally affected by two other design choices: the number of allocations and the degree of the allocations’ dependence. We prove that the more allocations, the higher the power and the lower the variability in power. Our theoretical findings and simulation studies show that the designs with the highest power provide thousands of highly independent allocations each providing nominal imbalance in the observed covariates. These high-powered designs exhibit less randomness than complete randomization and more randomness than recently proposed designs that employ numerical optimization. This advantage of high power is easily accessible to practicing experimenters via the popular rerandomization design and a greedy pair switching design, where both outperform complete randomization and numerical optimization. The tradeoff we find also provides a means to specify rerandomization’s imbalance threshold parameter.

Objective This study examined how features of the observer and observed contribute to stigma in Alzheimer's disease (AD). To do this, we conducted a vignette experiment examining how participant and patient gender identities modify AD stigma. Participants A sample of 1,817 U.S. adult men and women invited at random. Methods Participants read a vignette about a hypothetical patient that was either a man or woman. The patient's clinical characteristics varied by symptom stage (from Clinical Dementia Rating stage 0, no impairment, to 2, moderate dementia), biomarker result (positive vs. negative), and disease-modifying treatment (available vs. unavailable). Multiple regression analyses assessed whether participant gender, patient gender, or their interaction influenced ratings on the Modified Family Stigma in Alzheimer's Disease Scale. Findings In comparisons of mild stage symptoms and no clinical symptoms, women made stronger attributions of symptom severity than men (aOR=1.60, 95%CI 1.06 to 2.40) and expressed stronger support (aOR=1.62, 95%CI 1.09 to 2.40) than men. In comparisons of a positive vs. negative biomarker test result, women had a larger increase than men in worries about structural discrimination (aOR=1.39, 95%CI 1.01 to 1.92) and pity (aOR=1.52, 95%CI 1.10 to 2.10). The female patient in the vignette evoked fewer negative aesthetic attributions compared to the male patient (aOR=0.79, 95%CI 0.66 to 0.95). Conclusions In most instances, participant gender effects modified AD stigma while patient effects did not. Men may be judged more harshly as patients, while women may experience a worse internalized stigma. The findings advance understanding of AD stigma mechanisms.

OBJECTIVES:This study assessed the state of pediatric medical device (PMD) development by comparing PMD clinical trials to pediatric trials evaluating drugs and biologics, from 1999 to 2022. METHODS:The site www.clinicaltrials.gov was used to identify and quantify both PMD clinical trials and pediatric trials for drugs and biologics. Clinical specialty was also assessed. The institutions included were the 7 children's hospitals primarily affiliated with the Food and Drug Administration (FDA) Pediatric Device Consortia (PDC) grant program between 2018 and 2023. For a national comparison, an additional search assessed PMD trials across all US medical institutions. RESULTS:A total of 243 PMD clinical trials were identified at the FDA-PDC institutions on the basis of the year of initiation; the average number of PMD trials initiated per year per institution was 1.5 from 1999 to 2022. However, PMD trials significantly increased during the period 2014 to 2022 compared with 1999 to 2013 (P < .001); the rate of initiation of drug and biologic pediatric trials demonstrated no significant differences between these time periods. A national survey of all institutions initiating PMD trials, and drugs and biologics trials, identified 1885 PMD trials out of a total 12 943. A comparable trend was noted in the national survey with initiation of PMD trials increasing significantly from 2014 to 2022 (P < .001), compared with 1999 to 2013, whereas the rate of initiation of drug and biologic trials during these periods did not demonstrate a significant change. CONCLUSIONS:Although pediatric clinical trial initiation for drugs and biologics remained stable from 1999 to 2022, the rate of new PMD trials significantly increased during the period 2014 to 2022 at FDA-PDC institutions and nationally.

Objectives: Early diagnosis of Alzheimer's disease (AD) using brain scans and other biomarker tests will be essential to increasing the benefits of emerging disease-modifying therapies, but AD biomarkers may have unintended negative consequences on stigma. We examined how a brain scan result affects AD diagnosis confidence and AD stigma. Methods: The study used a vignette-based experiment with a 2 x 2 x 3 factorial design of main effects: a brain scan result as positive or negative, treatment availability and symptom stage. We sampled 1,283 adults ages 65 and older between June 11and July 3, 2019. Participants (1) rated their confidence in an AD diagnosis in each of four medical evaluations that varied in number and type of diagnostic tools and (2) read a vignette about a fictional patient with varied characteristics before completing the Modified Family Stigma in Alzheimer's Disease Scale (FS-ADS). We examined mean diagnosis confidence by medical evaluation type. We conducted between-group comparisons of diagnosis confidence and FS-ADS scores in the positive versus negative brain scan result conditions and, in the positive condition, by symptom stage and treatment availability. Results: A positive versus negative test result corresponds with higher confidence in an AD diagnosis independent of medical evaluation type (all p < .001). A positive result correlates with stronger reactions on 6 of 7 FS-ADS domains (all p < .001). Discussion: A positive biomarker result heightens AD diagnosis confidence but also correlates with more AD stigma. Our findings inform strategies to promote early diagnosis and clinical discussions with individuals undergoing AD biomarker testing.

OBJECTIVE:We urgently need to understand Alzheimer's disease (AD) stigma among Black adults. Black communities bear a disproportionate burden of AD, and recent advances in early diagnosis using AD biomarkers may affect stigma associated with AD. The goal of our study is to characterize AD stigma within our cohort of self-identified Black participants and test how AD biomarker test results may affect this stigma. DESIGN:We surveyed a sample of 1,150 self-identified Black adults who were randomized to read a vignette describing a fictional person, who was described as either having a positive or negative biomarker test result. After reading the vignette, participants completed the modified Family Stigma in Alzheimer's Disease Scale (FS-ADS). We compared FS-ADS scores between groups defined by age, gender, and United States Census region. We examined interactions between these groupings and AD biomarker test result. RESULTS:Participants over age 65 had lower scores (lower stigma) on all 7 FS-ADS domains compared to those under 65: structural discrimination, negative severity attributions, negative aesthetic attributions, antipathy, support, pity, and social distance. In the biomarker positive condition, worries about structural discrimination were greater than in the biomarker negative condition and statistically similar in the two age groups (DOR, 0.39 [95%CI, 0.22-0.69]). This pattern of results was similar for negative symptom attributions (DOR, 0.51 [95%CI, 0.28-0.90]). CONCLUSION:While older adults reported less AD stigma than younger adults, AD biomarker testing caused similarly high concerns about structural discrimination and negative severity attributions. Thus, use of AD biomarker diagnosis may increase AD stigma and exacerbate healthcare disparities known to effect AD diagnosis in some Black adults. Advances in AD diagnosis may interact with social and structural factors to differentially affect groups of Black adults.

We present a new experimental design procedure that divides a set of experimental units into two groups in order to minimize error in estimating a treatment effect. One concern is the elimination of large covariate imbalance between the two groups before the experiment begins. Another concern is robustness of the design to misspecification in response models. We address both concerns in our proposed design: we first place subjects into pairs using optimal nonbipartite matching, making our estimator robust to complicated nonlinear response models. Our innovation is to keep the matched pairs extant, take differences of the covariate values within each matched pair, and then use the greedy switching heuristic of Krieger et al. (2019) or rerandomization on these differences. This latter step greatly reduces covariate imbalance. Furthermore, our resultant designs are shown to be nearly as random as matching, which is robust to unobserved covariates. When compared to previous designs, our approach exhibits significant improvement in the mean squared error of the treatment effect estimator when the response model is nonlinear and performs at least as well when the response model is linear. Our design procedure can be found as a method in the open source R package available on CRAN called GreedyExperimentalDesign.

INTRODUCTION:How do reactions to a brain scan result differ between Black and White adults? The answer may inform efforts to reduce disparities in Alzheimer's disease (AD) diagnosis and treatment. METHODS:Self-identified Black (n = 1055) and White (n = 1451) adults were randomized to a vignette of a fictional patient at a memory center who was told a brain scan result. Measures of stigma and diagnosis confidence were compared between-groups. RESULTS:Black participants reported more stigma than White participants on four of seven domains in reaction to the patient at a memory center visit. Black participants' confidence in an AD diagnosis informed by a brain scan and other assessments was 72.2 points (95% confidence interval [CI] 70.4 to 73.5), which was lower than the respective rating for White participants [78.1 points (95%CI 77.0 to 79.3)]. DISCUSSION:Equitable access to early AD diagnosis will require public outreach and education that address AD stigma associated with a memory center visit.

Studying thousands of families, we find siblings concordant for autism share more of their parental genomes than expected by chance, and discordant siblings share less, consistent with a role of transmission in autism incidence. The excess sharing of the father is highly significant (p value of 0.0014), with less significance for the mother (p value of 0.31). To compare parental sharing, we adjust for differences in meiotic recombination to obtain a p value of 0.15 that they are shared equally. These observations are contrary to certain models in which the mother carries a greater load than the father. Nevertheless, we present models in which greater sharing of the father is observed even though the mother carries a greater load. More generally, our observations of sharing establish quantitative constraints that any complete genetic model of autism must satisfy, and our methods may be applicable to other complex disorders.

Objective This study assessed the state of PMD development by comparing PMD clinical trials to pediatric trials evaluating drugs and biologics, from 1999-2022. We hypothesized changes in numbers and types of PMD trials compared to drugs and biologics represent an indicator of PMD growth.Study Design [www.clinicaltrials.gov][1] was used to identify and quantify both PMD clinical trials and pediatric trials for drugs and biologics. Clinical specialty was also assessed. The institutions included were the seven children’s hospitals primarily affiliated with the FDA PDC grants program between 2018-2023.Results 243 PMD clinical trials were identified based on the year of initiation. The average number of PMD trials initiated per year per institution was 1.5. PMD trials significantly increased (p=0.0083) from 2014 onward compared to pediatric clinical trials for drugs and biologics, which demonstrated no significant change in trial initiation activity. A more than five-fold increase in PMD trials was observed from 2014-2018 compared to previous time periods, and there were 48% more PMD trials from 2019-2022 compared to 2014-2018. PMD trials represented 5% of clinical trials at the institutions studied.Conclusions While clinical trial activity for drug and biologic development remained stable from 1999-2022, initiation of PMD trials significantly increased. The present results suggest that clinical trials growth reflects increased PMD development. Accommodation and promotion of PMD clinical trial activity, which is still relatively small, by relevant programs and policies at the institutional and government levels may foster the advancement of PMD to further address unmet needs.Article Summary This article is an analysis of device trials performed at seven children’s hospitals affiliated with the FDA Consortia grants program between 1999 and 2022.What’s Known on This Subject There have been no prior studies of device trial activity at a cohort of children’s hospitals at academic medical centers. Over the past decade, FDA programs have been initiated to assist stakeholders in advancing the development of pediatric medical devices.What This Study Adds Pediatric device trials account for only 5% of total trials at the institutions studied. Of note, only half of these PMD trials (2.4% of total clinical trials) were sponsored by industry and likely seeking pediatric labeling.### Competing Interest StatementThe authors have declared no competing interest.### Funding StatementThis manuscript is supported by the Food and Drug Administration (FDA) of the U.S. Department of Health and Human Services (HHS) as part of awards totaling $150,000.00 with 0% financed with non-governmental sources. The contents are those of the author(s) and do not necessarily represent the official views of, nor an endorsement, by FDA, HHS, or the U.S. Government. For more information, please visit FDA.gov. The FDA had no role in the design and conduct of this study.### Author DeclarationsI confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained.YesThe details of the IRB/oversight body that provided approval or exemption for the research described are given below:The study used ONLY openly available human data that were originally located at: https://www.clinicaltrials.gov/I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals.YesI understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance).YesI have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable.YesAll data produced in the present study are available upon reasonable request to the authors* FDA : Food and Drug Administration CDRH : Center for Devices and Radiological Health PMD : Pediatric medical device(s) PDC : Pediatric Device Consortia OOPD : Office of Orphan Products Development CHLA : Children’s Hospital Los Angeles CHOP : Children’s Hospital of Philadelphia CNH : Children’s National Hospital LPCHS : Lucile Packard’s Children’s Hospital Stanford TCH : Texas Children’s Hospital UCSF BCH : University of California San Francisco Benioff Children’s Hospital UPMC CHP : University of Pittsburgh Medical Center Children’s Hospital of Pittsburgh [1]: http://www.clinicaltrials.gov

We consider the problem of evaluating designs for a two-arm randomised experiment with an incidence (binary) outcome under a non-parametric general response model. Our two main results are that the a priori pair matching design is (1) the optimal design as measured by mean squared error among all block designs which includes complete randomisation. And (2), this pair-matching design is minimax, that is, it provides the lowest mean squared error under an adversarial response model. Theoretical results are supported by simulations and clinical trial data where we demonstrate the superior performance of pairwise matching designs under realistic conditions.

Degenerative mitral valve (MV) regurgitation (MR) is a highly prevalent heart disease that requires surgery in severe cases. Here, we show that a decrease in the activity of the serotonin transporter (SERT) accelerates MV remodeling and progression to MR. Through studies of a population of patients with MR, we show that selective serotonin reuptake inhibitor (SSRI) use and SERT promoter polymorphism 5-HTTLPR LL genotype were associated with MV surgery at younger age. Functional characterization of 122 human MV samples, in conjunction with in vivo studies in SERT-/- mice and wild-type mice treated with the SSRI fluoxetine, showed that diminished SERT activity in MV interstitial cells (MVICs) contributed to the pathophysiology of MR through enhanced serotonin receptor (HTR) signaling. SERT activity was decreased in LL MVICs partially because of diminished membrane localization of SERT. In mice, fluoxetine treatment or SERT knockdown resulted in thickened MV leaflets. Similarly, silencing of SERT in normal human MVICs led to up-regulation of transforming growth factor β1 (TGFβ1) and collagen (COL1A1) in the presence of serotonin. In addition, treatment of MVICs with fluoxetine not only directly inhibited SERT activity but also decreased SERT expression and increased HTR2B expression. Fluoxetine treatment and LL genotype were also associated with increased COL1A1 expression in the presence of serotonin in MVICs, and these effects were attenuated by HTR2B inhibition. These results suggest that assessment of both 5-HTTLPR genotype and SERT-inhibiting treatments may be useful tools to risk-stratify patients with MV disease to estimate the likelihood of rapid disease progression.

Significance Heart valve disease affects millions, and since there is no effective medical therapy, surgical repair when possible—or more commonly, replacement—are the only treatments available. Bioprosthetic heart valves (BHV), the most frequently used valve replacements, are composed of heterograft tissue, typically fixed in glutaraldehyde, and prepared for human use either as surgically implantable devices or for transcatheter delivery. Protein-glycation limits the durability of BHV, contributing to device failure, often requiring reoperation after only a decade or less of functionality. This problem is addressed by modifying BHV leaflets with poly-2-methyl-2-oxazoline, effectively mitigating glycation and serum protein infiltration and enhancing biocompatibility. Bioprosthetic heart valves (BHV) fabricated from glutaraldehyde-fixed heterograft tissue, such as bovine pericardium (BP), are widely used for treating heart valve disease, a group of disorders that affects millions. Structural valve degeneration (SVD) of BHV due to both calcification and the accumulation of advanced glycation end products (AGE) with associated serum proteins limits durability. We hypothesized that BP modified with poly-2-methyl-2-oxazoline (POZ) to inhibit protein entry would demonstrate reduced accumulation of AGE and serum proteins, mitigating SVD. In vitro studies of POZ-modified BP demonstrated reduced accumulation of serum albumin and AGE. BP-POZ in vitro maintained collagen microarchitecture per two-photon microscopy despite AGE incubation, and in cell culture studies was associated with no change in tumor necrosis factor-α after exposure to AGE and activated macrophages. Comparing POZ and polyethylene glycol (PEG)–modified BP in vitro, BP-POZ was minimally affected by oxidative conditions, whereas BP-PEG was susceptible to oxidative deterioration. In juvenile rat subdermal implants, BP-POZ demonstrated reduced AGE formation and serum albumin infiltration, while calcification was not inhibited. However, BP-POZ rat subdermal implants with ethanol pretreatment demonstrated inhibition of both AGE accumulation and calcification. Ex vivo laminar flow studies with human blood demonstrated BP-POZ enhanced thromboresistance with reduced white blood cell accumulation. We conclude that SVD associated with AGE and serum protein accumulation can be mitigated through POZ functionalization that both enhances biocompatibility and facilitates ethanol pretreatment inhibition of BP calcification.

Objective: The symptoms and prognosis of Alzheimer's disease (AD) dementia contribute to the public's negative reactions toward individuals with AD dementia and their families. But what if, using AD biomarker tests, diagnosis was made before the onset of dementia, and a disease-modifying treatment was available? This study tests the hypotheses that a "preclinical" diagnosis of AD and treatment that improves prognosis will mitigate stigmatizing reactions. Methods: A sample of U.S. adults were randomized to receive one vignette created by a 3 x 2 x 2 vignette-based experiment that described a person with varied clinical symptom severity (Clinical Dementia Rating stages 0 (no dementia), 1 (mild), or 2 (moderate)), AD biomarker test results (positive vs negative), and disease-modifying treatment (available vs not available). Between-group comparisons were conducted of scores on the Modified Family Stigma in Alzheimer's Disease Scale (FS-ADS).Results: The sample of 1,817 adults had a mean age two years younger than that of U.S. adults but was otherwise similar to the general adult population. The response rate was 63% and the completion rate was 96%. In comparisons of randomized groups, mild and moderate symptoms of dementia evoked stronger reactions on all FS-ADS domains compared to no dementia (all p < 0.001). A positive biomarker test result evoked stronger reactions on all but one FS-ADS domain (negative aesthetic attributions) compared to a negative biomarker result (all p < 0.001). Disease-modifying treatment had no measurable influence on stigma (all p > 0.05).Conclusions: The stigmas of dementia spill over into preclinical AD, and availability of treatment does not alter that stigma. Translation of the preclinical AD construct from research into practice will require interventions that mitigate AD stigma to preserve the dignity and identity of individuals living with AD.