Chaperoning of specific tau structure by immunophilin FKBP12 regulates the neuronal resilience to extracellular stress

Alzheimer's disease and related tauopathies are characterized by the pathogenic misfolding and aggregation of the microtubule-associated protein tau. Understanding how endogenous chaperones modulate tau misfolding could guide future therapies. Here, we show that the immunophilin FKBP12, the 12-kDa FK506-binding protein (also known as FKBP prolyl isomerase 1A), regulates the neuronal resilience by chaperoning a specific structure in monomeric tau. Using a combination of mouse and cell experiments, in vitro aggregation experiments, nuclear magnetic resonance-based structural analysis of monomeric tau, site-specific phosphorylation and mutation, as well as structure-based analysis using the neural network-based structure prediction program AlphaFold, we define the molecular factors that govern the binding of FKBP12 to tau and its influence on tau-induced neurotoxicity. We further demonstrate that tyrosine phosphorylation of tau blocks the binding of FKBP12 to two highly specific structural motifs in tau. Our data together with previous results demonstrating FKBP12/tau colocalization in neurons and neurofibrillary tangles support a critical role of FKBP12 in regulating tau pathology.

Phase 1b study to assess the safety of neoadjuvant trifluridine/tipiracil with concurrent radiation in resectable stage II/III rectal cancer

TPS274

Background: Treatment of locally advanced rectal cancer currently involves tri-modal therapy with pre-operative chemo-radiation (CRT), surgery, and combination chemotherapy. Total neoadjuvant therapy (TNT) is emerging as an important treatment pathway that can increase rates of complete response (CR) leading to better overall outcomes. Novel radio-sensitizing agents may improve rates of CR. Trifluridine/tipiracil (TFD/TPI) is a novel fluoropyrimidine that has demonstrated clinical efficacy in patients with treatment-refractory metastatic colorectal cancer. Importantly, TFD/TPI has superior radio-sensitization in vitro compared to 5-fluorouracil, and we hypothesize that this can improve the tumor response of patients. This phase 1 study assesses the safety and preliminary efficacy of using TFD/TPI for long-course CRT for rectal cancer followed by FOLFOX chemotherapy in the TNT setting. Methods: NCT04104139 is a prospective, dose-finding phase I study using Bayesian Optimal Interval (BOIN) design to determine the maximum tolerated dose (MTD) of TFD/TPI with concurrent standard dose/fractionation radiation for resectable rectal cancer. Adults with previously untreated rectal adenocarcinoma, with clinical stage II (T3-4aN0) and stage III (T1-4aN1+) by MRI and endoscopy are eligible. Patients must first receive CRT with standard radiation (45-50 Gy over 25-28 fractions) followed by up to 8 cycles of standard FOLFOX, or alternatively 5 cycles of CAPOX chemotherapy. During CRT, the first dose level of TFD/TPI is PO 25mg/m2 twice a day from Mon to Fri (5 weekdays) alternating on weeks 1, 3, and 5 concurrent with 5-6 weeks of radiation. The second dose level is 30mg/m2, and third dose level is 35mg/m2. The MTD of TFD/TPI in combination with radiation is the dose corresponding to a dose limiting toxicity (DLT) probability of 30% using the BOIN design with escalation/de-escalation of each dose level occurring in cohorts of 3 participants until a maximum total of 18 participants, sub-total of 12 patients within one dose level, or another stopping rule based on serious toxicities. The primary endpoint is proportion of DLTs for TFD/TPI at MTD. Secondary endpoints include overall tolerability profile, delayed toxicities during FOLFOX, rates of clinical CR, rates of pathologic CR, and correlative biomarkers. The study was activated December 2019 and has accrued 8 of intended 18 patients. Clinical trial information: NCT04104139 .

Prevention and screening during the COVID-19 pandemic: qualitative findings from the BETTER WISE project

BACKGROUND

The COVID-19 pandemic challenged healthcare systems worldwide and disrupted primary care, particularly prevention, screening, and lifestyle counselling. BETTER WISE is a comprehensive and structured approach that proactively addresses cancer and chronic disease prevention and screening (CCDPS), including cancer survivorship and screening for poverty and lifestyle risks for patients aged 40 to 65. Patients from 13 primary care clinics (urban, rural, and remote) in Alberta, Ontario, and Newfoundland & Labrador, Canada were invited for a 1-hour visit with a prevention practitioner (PP), a member of the primary care team with specialized training in CCDPS to provide patients an overview of eligible screening and assist with lifestyle counselling. This qualitative sub-study describes how the COVID-19 pandemic impacted BETTER WISE in a constantly changing medical landscape.

METHODS

We conducted 17 focus groups and 48 key informant interviews with a total of 132 primary care providers (PPs, physicians, allied health professionals, and clinic staff) over three different time points to better understand their perspectives on the BETTER WISE project. We also received 585 patient feedback forms of the 1005 patients who agreed to participate in the study. We also collected field notes and memos and employed thematic analysis using a constant comparative method focused on the impact of the pandemic on BETTER WISE.

RESULTS

We identified four themes related to how the COVID-19 pandemic impacted the BETTER WISE study: 1) Switch of in-person visits to visits over the phone; 2) Lack of access to preventive care and delays of screening tests; 3) Changes in primary care providers' availability and priorities; 4) Mental health impacts of the pandemic on patients and primary care providers.

CONCLUSIONS

The COVID-19 pandemic had and, at the time of writing, continues to have an impact on primary care, particularly on prevention, screening, and lifestyle counselling. Despite structural, procedural, and personal challenges throughout different waves of the pandemic, the primary care clinics participating in BETTER WISE were able to complete the study. Our results underscore the importance of the role of primary care providers in adapting to changing circumstances and support of patients in these challenging times.

TRIAL REGISTRATION

This qualitative study is a sub-component of the BETTER WISE pragmatic, cRCT, trial registration ISRCTN21333761 (date of registration 19/12/2016).

Dose-response effects of two nicotine salt formulations on electronic cigarette appeal and sensory attributes

OBJECTIVES

Various organic acids are used to create nicotine salt formulations, which may improve the appeal and sensory experience of vaping electronic cigarettes (e-cigarettes). This clinical experiment examined the effects of partially and highly protonated forms of two nicotine salt formulations (nicotine lactate and benzoate) versus free-base (no acid additive) on the appeal and sensory attributes of e-cigarettes.

METHODS

Current adult tobacco product users (n=116) participated in an online remote double-blind within-subject randomised experiment involving standardised self-administration of e-cigarette solutions varying in nicotine formulation (free-base, 50% nicotine lactate -1:2 lactic acid to nicotine molar ratio, 100% nicotine lactate - 1:1 ratio, 50% nicotine benzoate and 100% nicotine benzoate). Each formulation had equivalent nicotine concentrations (27.0-33.0 mg/mL) and was administered in four flavours in a pod-style device. After each administration, participants rated appeal (liking, disliking and willingness to use again) and sensory attributes (0-100 scale).

RESULTS

Compared with free-base nicotine, 50% and 100% nicotine lactate and benzoate yielded higher appeal, smoothness and sweetness and lower harshness and bitterness. Dose-response analyses found 100% vs 50% nicotine salt improved appeal, smoothness, bitterness and harshness for nicotine lactate and sweetness, smoothness and harshness for nicotine benzoate. Solutions with higher pH were associated with worse appeal and sensory attributes across nicotine formulations. Nicotine formulation effects did not differ by tobacco use status and flavours.

CONCLUSION

Restricting benzoic acid or lactic acid additives or setting minimal pHs in e-cigarettes merits consideration in regulations designed to reduce vaping among populations deterred from using e-cigarettes with aversive sensory properties.

TRIAL REGISTRATION NUMBER

This study was registered under ClinicalTrials.gov Identifier: NCT03742817 under the title 'Effects of e-Cigarettes on Perceptions and Behavior'.

Prevalence of and disparities in adolescents' susceptibility to novel oral nicotine products marketed as "tobacco-free"

Non-therapeutic, novel oral nicotine products are convenient, discreet to use, and flavored, with increasing sales in the United States. It is unclear whether these products appeal predominantly to adolescents already susceptible to inhalable nicotine products, or whether they attract adolescents who would not otherwise use nicotine. This study examined prevalence and correlates of susceptibility to inhalable and oral nicotine product use among adolescents. Ninth- and tenth-grade students from Southern California who had never used any nicotine product (N = 3129) completed an online survey in Fall 2021 assessing susceptibility to inhalable (i.e., cigarettes, e-cigarettes) and oral (e.g., pouches, gum, gummies) nicotine products. Multinomial logistic regression analyses estimated associations of demographic characteristics with odds of susceptibility to oral, inhalable, or both products. Susceptibility was highest for e-cigarettes (19.7%), followed by cigarettes (15.0%) and nicotine gum, lozenges, tablets and/or gummies (15.0%), and nicotine pouches (8.7%). Dual susceptibility to oral and inhalable products (vs. neither product type) was higher in cisgender female and non-cisgender (vs. cisgender male) adolescents (odds ratios [ORs] = 1.36-2.02; ps < 0.05). Hispanic adolescents (vs. Asian) were more susceptible to both products (OR = 1.47; p < .05). Lower-socioeconomic status (SES) and sexual minority adolescents were more susceptible to oral (ORs = 1.76-1.87; ps < 0.05) and both products (ORs = 1.32-1.88; ps < 0.05), compared to higher-SES and heterosexual adolescents. Adolescents in Southern California may be more susceptible to e-cigarettes than other nicotine/tobacco products. However, appreciable numbers may be susceptible to oral nicotine products, including some youth who might not otherwise use nicotine and youth from populations historically impacted by tobacco-related health disparities.

Feasibility and acceptability of remote procedures to study tobacco product use and respiratory health: an observational study

OBJECTIVE

Obtaining ecologically valid biological samples is critical for understanding respiratory effects of tobacco use, but can be burdensome. In two diverse samples, we examined feasibility and acceptability of studying pulmonary function and respiratory health entirely remotely.

DESIGN

Observational feasibility and acceptability study.

SETTING AND PARTICIPANTS

Adults age 18-25 (Biomedical Respiratory Effects Associated through Habitual Use of E-Cigarettes [BREATHE] Study) and 21-65 (Adult IQOS Respiratory [AIRS] Study) recruited from previous research studies and advertisements in Southern California, USA (BREATHE (AIRS): N=77 (N=31) completed baseline, n=64 (n=20) completed feasibility and acceptability measures). Shared inclusion criteria for the two studies were ownership of a smartphone, willingness to download applications and English fluency. In addition, BREATHE participants reported one of three tobacco use patterns. AIRS participants smoked daily and were willing to use a heated tobacco product. Exclusion criteria were medical contraindications.

INTERVENTIONS

A 4-week study consisted of five virtual study visits, twice daily ecological momentary assessment diaries and spirometry assessments, and weekly Nasal Epithelial Lining Fluid and saliva collection. All study visits were conducted via video conference; study materials and biospecimens were exchanged via mail. Participants reported feasibility and acceptability of daily diaries, breath tests, biospecimen collection and shipments.

MEASURES

Surveys assessed perceptions of timing and overall experience of daily diaries and breath tests, difficulty of and overall experience with biospecimen collection, and experience sending and receiving shipments.

RESULTS

Most participants evaluated daily diaries and breath tests as manageable (62.5%-95.0%) and likeable (54.7%-70.0%). Breath tests were frequently described as 'interesting' (55.0%-57.8%) and 'easy' (25.0%-48.4%). Most participants reported that biospecimen collection was easy (50.0%-85.0%), and that shipments were easy to send (87.5%-95.0%), receive (95.3%-95.0%) and schedule (56.3%-60.0%). No participants received shipments in poor condition.

CONCLUSIONS

Remote research procedures may be feasible and acceptable to facilitate tobacco research studies, potentially resulting in more diverse samples of participants and more generalisable research results.

Third-generation cephalosporin resistant gram-negative bacteraemia in patients with haematological malignancy; an 11-year multi-centre retrospective study

Objectives

Among patients with haematological malignancy, bacteraemia is a common complication during chemotherapy-induced neutropenia. Resistance of gram-negative bacteria (GNB) to third-generation cephalosporins (3GC) is increasing. In order to explore the value of using surveillance cultures to guide empirical treatment e.g. choosing between carbapenem versus ceftazidime- we aimed to assess the distribution of pathogens causing bacteraemia in patients with haematological malignancy, and the proportion of 3GC-resistant GNB (3GC-R GNB) bacteraemia that was preceded by 3GC-R GNB colonization.

Methods

Using 11 years of data (2008–2018) from the Dutch national antimicrobial resistance surveillance system, we assessed the prevalence of 3GC-R GNB in episodes of bacteraemia, and the proportion of 3GC-R GNB bacteraemia that was preceded by 3GC-R GNB colonization. Colonization was defined as availability of any GNB surveillance isolate in the year before, independent of the causative micro-organism (time-paired isolates).

Results

We included 3887 patients, representing 4142 episodes of bacteraemia. GNB were identified in 715/4142 (17.3%), of which 221 (30.9%) were 3GC-R GNB. In 139 of these 221 patients a time-paired surveillance culture was available. In 76.2% (106/139) of patients these surveillance cultures already showed 3GC-R GNB isolates in the year prior to the culture date of the 3GC-R GNB positive blood isolate.

Conclusions

This multi-centre study shows that in patients with haematological malignancy, the majority of 3GC-R GNB bacteraemia is preceded by 3GC-R GNB colonization. Prospective clinical studies are needed to assess the safety and benefits of the use of surveillance-cultures to guide empirical therapy to restrict the empirical use of carbapenems in this population.

The association between native myocardial T1 relaxation times and left atrial phasic structure and function: the UK Biobank Imaging Enhancement study

Introduction

Left ventricular (LV) myocardial fibrosis is posited to result in left atrial (LA) changes via LV remodelling and diastolic dysfunction, though the association remains poorly characterised. Native myocardial T1 mapping is a non-invasive modality that quantifies diffuse myocardial fibrosis. This study examines the relationship between LV fibrosis (quantified by native T1 times) and LA function, drawing upon data from the UK Biobank.

Methods

40,818 participants underwent cardiovascular magnetic resonance (CMR) using steady-state free precession imaging at 1.5 Tesla. Native T1-mapping was performed using the Shortened Modified Look-Locker Inversion recovery technique (ShMOLLI), with global myocardial T1 estimated by an automatic segmentation framework. Nine parameters of LA phasic function were calculated (representing global, reservoir, conduit and booster components) from normalised LA volume-time curves. LV parameters (LV Mass, end-diastolic volume and ejection fraction) were extracted by a convolutional neural network. Multivariable logistic regression models were used to assess the association between T1 (exposure) and LA function (outcome). Mediation analysis was performed to assess the role of LV parameters as a mediator for the association between T1 and LA function. Lastly, potential non-linear relationships between T1 and LA function were investigated using Restrictive Cubic Spline (RCS) modelling, with model fit assessed via the Akaike Information Criterion (AIC).

Results

Higher T1 values were positively associated with larger LA volumes, and negatively associated with markers of LA global, reservoir and booster function. In the fully adjusted model, T1 was positively associated with larger LA minimum size (Beta: +0.034 SD per T1 SD; Confidence Interval (CI): 0.024, 0.045), and negatively associated with LA emptying volume (Beta: −0.017; CI: −0.027, −0.006), LA booster volume (Beta: −0.019; CI: −0.030, −0.008), LA emptying fraction (Beta: −0.052; CI: −0.062, −0.041), and LA reservoir function (Beta: −0.028; CI: −0.039, −0.017). Though adjustment for LV parameters did not fully attenuate the above relationships, LV parameters were consistent mediators between T1 and LA function, with proportional mediative effects ranging from 15% to 75%. Lastly, there is evidence of an inverted J-shaped relationship between T1 and LA function, with the associations becoming more apparent in the upper half of T1 ranges (turning points within 925–950 ms, median T1 = 930 ms) (p&lt;0.05).

Conclusion

This study demonstrates a consistent association between higher native T1 values (as a marker of myocardial fibrosis) and lower LA global and phasic functions. We also highlighted an interplay between T1 values, LV remodelling and LA dysfunction. These findings will facilitate our understanding of the disease processes underlying cardiac dysfunction and myocardial remodelling at an early, subclinical stage.

Funding Acknowledgement

Type of funding sources: Public hospital(s). Main funding source(s): This work was part of the portfolio of translational research of the National Institute for Health Research Biomedical Research Centre at Barts and The London School of Medicine and DentistryDr Nay Aung is supported by a Wellcome Trust Research Training Fellowship (203553/Z/16/Z)

Child self-reported quality of life in pediatric intestinal failure

BACKGROUND

Recent studies have focused on parent-reported health-related quality of life (HRQOL) in children with intestinal failure (IF). However, there is a paucity of data on HRQOL from the perspective of the child with IF.

METHODS

A prospective study of child self-reported HRQOL was performed in a regional intestinal rehabilitation program from 2015 to 2019. The PedsQL 4.0 Generic Core Scales were administered annually to children with IF ages five years and older along with their parents. Survey data was stratified by age and compared with parent-proxy scores and reference populations of healthy and chronically ill children. Linear mixed-effect models were constructed to identify associations with child self-reported HRQOL.

RESULTS

A total of 140 surveys were administered to 69 children and their parents. Median child age at survey was 8 (IQR 6-10) years. Child self-reported HRQOL scores increased with each increasing age range. Children reported higher HRQOL scores compared to parent-proxy data in all age groups. Children with IF had lower HRQOL scores compared to healthy children in all survey dimensions (p < 0.001) and to children with chronic illness in the school and social functioning dimensions (p < 0.05). In adjusted analysis, longer remnant bowel length was independently associated with decreased HRQOL scores in children (p < 0.05).

CONCLUSIONS

Children with IF reported better HRQOL compared to parent-proxy data. While these HRQOL scores improved with age, they remain significantly lower than healthy and chronically ill peers. The association between bowel length and child-reported HRQOL deserves further investigation.

LEVEL OF EVIDENCE

Level II.

Adolescent Use of Flavored Non-Tobacco Oral Nicotine Products

BACKGROUND AND OBJECTIVES

Flavored non-tobacco oral nicotine products (eg, nicotine pouches and nontherapeutic nicotine gum, lozenges, tablets, gummies), are increasingly marketed in the United States. Prevalence of non-tobacco oral nicotine product use among adolescents is unknown.

METHODS

We calculated prevalence of ever and past 6-month use of nicotine pouches, other non-tobacco oral nicotine products (ie, gum, lozenges, tablets, and/or gummies), e-cigarettes, cigarettes, hookah or waterpipe, cigars, cigarillos, and snus among high school students in Southern California between September and December 2021. Generalized linear mixed models tested associations of sociodemographic factors and tobacco-product use with use of any non-tobacco oral nicotine product.

RESULTS

Among the sample (n = 3516), prevalence was highest for e-cigarettes (ever: 9.6%, past 6-month: 5.5%), followed by non-tobacco oral nicotine products (ever: 3.4%, past 6-month: 1.7%), and <1% for other products. Ever users of combustible tobacco (adjusted odds ratio [aOR] = 77.6; 95% confidence interval [CI] = 39.7-152) and ever users of noncombustible tobacco (aOR = 40.4; 95% CI= 24.3-67.0) had higher odds of ever using non-tobacco oral nicotine products, compared to never users of combustible and noncombustible tobacco. Use of any non-tobacco oral nicotine product was greater for Hispanic (versus all other races/ethnicities except Asian, aOR = 2.58; 95% CI = 1.36-4.87), sexual minority (versus heterosexual, aOR=1.63; 95% CI = 1.03-2.57), gender minority (versus male, aOR = 2.83; 95% CI = 1.29-6.19), and female (versus male, aOR=1.92, 95% CI = 1.20-3.06) participants.

CONCLUSIONS

Non-tobacco oral nicotine products were the second most prevalent nicotine product used by adolescents. They were disproportionately used by certain racial or ethnic, sexual, or gender minority groups, and those with a history of nicotine use. Adolescent non-tobacco oral nicotine product use surveillance should be a public health priority.

Efficacy of transrectal ultrasound in assessing endometrium of postmenopausal women with axial uterus

OBJECTIVE

To evaluate the acceptance and efficacy of transrectal ultrasound (TRS) in assessing the endometrium in postmenopausal women with an axial uterus.

METHODS

This was a prospective cross-sectional study conducted between October 2015 and October 2018 of consecutive postmenopausal women with an axial uterus on transvaginal ultrasound (TVS). Women with a known diagnosis of gynecological malignancy were excluded. TRS was offered immediately after TVS without prior bowel preparation. A single operator determined subjectively whether the endometrium was visualized satisfactorily on TVS and TRS. In women with postmenopausal bleeding (PMB), endometrial thickness (ET) was measured and endometrial morphology was categorized as atrophic, uniformly thickened, benign endometrial polyp or endometrial cancer, based on subjective pattern recognition. All women with PMB and a non-atrophic endometrium underwent outpatient endometrial biopsy, hysteroscopy or hysterectomy. The success rate of TRS in assessing satisfactorily the endometrium was compared with that of TVS. In patients with PMB, ET measurements and subjective diagnosis of endometrial cancer on TVS vs TRS were compared.

RESULTS

Of the 1553 women who underwent TVS examination, 103 (6.6%) had an axial uterus, of whom 76 (73.8%) presented with PMB. TRS was accepted by 66/103 (64.1%) women with an axial uterus. TRS assessed satisfactorily a significantly higher proportion of endometria compared with TVS (90.9% vs 62.1%; χ2  = 14.1, P < 0.001). In 50 women with PMB and an axial uterus who underwent both TVS and TRS, TVS failed to visualize the endometrium satisfactorily in 15 (30.0%) women, whilst TRS provided satisfactory images in all cases. Among the 35 women with PMB and a satisfactory endometrial assessment on TVS and TRS, measurements of ET on TRS were significantly lower compared to those on TVS (median difference, -1.2 (interquartile range, -3.0 to -0.4) mm). The overall agreement of TVS and TRS on the presence or absence of endometrial cancer using subjective pattern recognition was 30/35 (85.7%; 95% CI, 74.1-97.3%). While all seven cases of histologically confirmed endometrial cancer were diagnosed correctly on TRS, four were misdiagnosed on TVS as benign polyps or uniformly thickened endometrium.

CONCLUSIONS

TRS is an acceptable and effective way to assess the endometrium in postmenopausal women with an axial uterus. Among women presenting additionally with PMB, TRS is associated with a higher proportion of satisfactory endometrial assessments and fewer misdiagnoses of endometrial cancer by subjective pattern recognition compared with TVS. © 2021 International Society of Ultrasound in Obstetrics and Gynecology.

Non-Native Amino Acid Click Chemistry-Based Technology for Site-Specific Polysaccharide Conjugation to a Bacterial Protein Serving as Both Carrier and Vaccine Antigen

Surface-expressed bacterial polysaccharides are important vaccine antigens but must be conjugated to a carrier protein for efficient antigen presentation and development of strong memory B cell and antibody responses, especially in young children. The commonly used protein carriers include tetanus toxoid (TT), diphtheria toxoid (DT), and its derivative CRM197, but carrier-induced epitopic suppression and bystander interference may limit the expanded use of the same carriers in the pediatric immunization schedule. Recent efforts to develop a vaccine against the major human pathogen group A Streptococcus (GAS) have sought to combine two promising vaccine antigens-the universally conserved group A cell wall carbohydrate (GAC) with the secreted toxin antigen streptolysin O (SLO) as a protein carrier; however, standard reductive amination procedures appeared to destroy function epitopes of the protein, markedly diminishing functional antibody responses. Here, we couple a cell-free protein synthesis (CFPS) platform, allowing the incorporation of non-natural amino acids into a C-terminally truncated SLO toxoid for the precise conjugation to the polyrhamnose backbone of GAC. The combined immunogen generated functional antibodies against both conserved GAS virulence factors and provided protection against systemic GAS challenges. CFPS may represent a scalable method for generating pathogen-specific carrier proteins for multivalent subunit vaccine development.

Biofluid markers of blood-brain barrier disruption and neurodegeneration in Lewy body spectrum diseases: A systematic review and meta-analysis

BACKGROUND

Mixed evidence supports blood-brain barrier (BBB) dysfunction in Lewy body spectrum diseases.

METHODS

We compare biofluid markers in people with idiopathic Parkinson's disease (PD) and people with PD dementia (PDD) and/or dementia with Lewy bodies (DLB), compared with healthy controls (HC). Seven databases were searched up to May 10, 2021. Outcomes included cerebrospinal fluid to blood albumin ratio (Q_alb), and concentrations of 7 blood protein markers that also reflect BBB disruption and/or neurodegenerative co-pathology. We further explore differences between PD patients with and without evidence of dementia. Random-effects models were used to obtain standardized mean differences (SMD) with 95% confidence interval.

RESULTS

Of 13,949 unique records, 51 studies were meta-analyzed. Compared to HC, Q_alb was higher in PD (N_PD/N_HC = 224/563; SMD = 0.960 [0.227-1.694], p = 0.010; I² = 92.2%) and in PDD/DLB (N_PDD/DLB/N_HC = 265/670; SMD = 1.126 [0.358-1.893], p < 0.001; I² = 78.2%). Blood neurofilament light chain (NfL) was higher in PD (N_PD/N_HC = 1848/1130; SMD = 0.747 [0.442-1.052], p < 0.001; I² = 91.9%) and PDD/DLB (N_PDD/DLB/N_HC = 183/469; SMD = 1.051 [0.678-1.423], p = 0.004; I² = 92.7%) than in HC. p-tau 181 (N_PD/N_HC = 276/164; SMD = 0.698 [0.149-1.247], p = 0.013; I² = 82.7%) was also higher in PD compared to HC. In exploratory analyses, blood NfL was higher in PD without dementia (N_PDND/N_HC = 1005/740; SMD = 0.252 [0.042-0.462], p = 0.018; I² = 71.8%) and higher in PDD (N_PDD/N_HC = 100/111; SMD = 0.780 [0.347-1.214], p < 0.001; I² = 46.7%) compared to HC. Q_alb (N_PDD/N_PDND = 63/191; SMD = 0.482 [0.189-0.774], p = 0.010; I²<0.001%) and NfL (N_PDD/N_PDND = 100/223; SMD = 0.595 [0.346-0.844], p < 0.001; I² = 3.4%) were higher in PDD than in PD without dementia.

CONCLUSIONS

Biofluid markers suggest BBB disruption and neurodegenerative co-pathology involvement in common Lewy body diseases. Greater evidence of BBB breakdown was seen in Lewy body disease with cognitive impairment.

Polycomb contraction differentially regulates terminal human hematopoietic differentiation programs

Background

Lifelong production of the many types of mature blood cells from less differentiated progenitors is a hierarchically ordered process that spans multiple cell divisions. The nature and timing of the molecular events required to integrate the environmental signals, transcription factor activity, epigenetic modifications, and changes in gene expression involved are thus complex and still poorly understood. To address this gap, we generated comprehensive reference epigenomes of 8 phenotypically defined subsets of normal human cord blood.

Results

We describe a striking contraction of H3K27me3 density in differentiated myelo-erythroid cells that resembles a punctate pattern previously ascribed to pluripotent embryonic stem cells. Phenotypically distinct progenitor cell types display a nearly identical repressive H3K27me3 signature characterized by large organized chromatin K27-modification domains that are retained by mature lymphoid cells but lost in terminally differentiated monocytes and erythroblasts. We demonstrate that inhibition of polycomb group members predicted to control large organized chromatin K27-modification domains influences lymphoid and myeloid fate decisions of primary neonatal hematopoietic progenitors in vitro. We further show that a majority of active enhancers appear in early progenitors, a subset of which are DNA hypermethylated and become hypomethylated and induced during terminal differentiation.

Conclusion

Primitive human hematopoietic cells display a unique repressive H3K27me3 signature that is retained by mature lymphoid cells but is lost in monocytes and erythroblasts. Intervention data implicate that control of this chromatin state change is a requisite part of the process whereby normal human hematopoietic progenitor cells make lymphoid and myeloid fate decisions.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12915-022-01315-1.

Early Discontinuation, Results Reporting, and Publication of Pediatric Clinical Trials

BACKGROUND AND OBJECTIVES

Unique ethical, epidemiological, and economic factors are barriers to performing research in children. The landscape of pediatric clinical trials, including drivers of completion and timely dissemination of results, is not well understood. We aimed to characterize the prevalence of and factors associated with early discontinuation, results reporting, and publication of pediatric clinical trials registered at ClinicalTrials.gov.

METHODS

Cross-sectional analysis of clinical trials enrolling participants <18 years old registered at ClinicalTrials.gov from October 2007 to March 2020. Multivariable logistic regressions were performed to assess the association between trial characteristics and primary outcomes. Publication data were obtained through PubMed, ClinicalTrials.gov, Embase, and Scopus.

RESULTS

Overall, 11.1% trials were stopped early, with recruitment failure being the predominant reason for discontinuation. Only 23.5% of completed trials reported results, and 38.8% were published within 3 years of completion. Rates of discontinuation and publication significantly improved over the study period. Among funding sources, government-sponsored trials (adjusted odds ratio [aOR], 0.72; 95% CI, 0.47-0.97) and academic trials (aOR, 0.64; 95% CI, 0.50-0.82) had lower odds of discontinuation compared with industry trials and were more likely to be published (government: aOR, 1.94 [95% CI, 1.52-2.48] academic: aOR, 1.61 [95% CI, 1.35-1.92). Academic trial investigators were the least likely to report results (aOR, 0.34; 95% CI, 0.31-0.52).

CONCLUSIONS

Early discontinuation and nonreporting/nonpublication of findings remain common in registered pediatric clinical trials and were associated with funding source and other trial features. Targeted efforts are needed to support trial completion and timely results dissemination toward strengthening evidence-based pediatric medicine.

Abstract 073: A Mediterranean Diet Pattern Is Associated With Lower Risk Of Adverse Pregnancy Outcomes In US Women: Results From The NuMoM2b Cohort

Introduction: Adverse pregnancy outcomes (APOs) are associated with an increased risk of developing cardiovascular disease (CVD). While the Mediterranean diet pattern has been inversely related to CVD outcomes, its association with APOs in US women has not been previously evaluated.

Hypothesis: Adherence to a Mediterranean diet pattern during the periconception period is associated with lower risk of APOs.

Methods: Racially and ethnically diverse women (n=8075, mean age: 27±6y) from the Nulliparous Pregnancy Outcomes Study: Monitoring Mothers-to-be (nuMoM2b) cohort were enrolled across 8 US medical centers from 2010-13. An Alternate Mediterranean Diet (aMed) score was computed from data on habitual diet in the 3 months around conception, assessed using a semi-quantitative food frequency questionnaire in the first trimester. APOs were prospectively ascertained and defined as developing 1 or more of the following: gestational hypertension, preeclampsia/eclampsia, gestational diabetes, preterm delivery, small for gestational age, or stillbirth. Multivariable logistic regression was used to examine associations of the aMed score and its components with any APO and individual APOs.

Results: Women in the highest vs. lowest quintile of the aMed score had 21% lower odds of developing any APO, and 36% and 52% lower odds of preeclampsia/eclampsia and gestational diabetes, respectively; a linear trend across aMed score categories was detected (p-trend<0.05) ( Figure ). When aMed score components were examined separately, higher intakes of vegetables, fruits, legumes, and fish and lower intakes of red meat were related to up to 26% lower odds of APOs.

Conclusions: Greater adherence to a Mediterranean diet pattern is related to lower risk of APOs, with evidence of a dose-response relationship, highlighting the potential of this diet pattern in CVD primordial prevention efforts in US women. Long-term studies are needed to assess whether dietary modification in the periconception period can reduce risk of APOs and future CVD.