Low-input and single-cell methods for Infinium DNA methylation BeadChips

The Infinium BeadChip is the most widely used DNA methylome assay technology for population-scale epigenome profiling. However, the standard workflow requires over 200 ng of input DNA, hindering its application to small cell-number samples, such as primordial germ cells. We developed experimental and analysis workflows to extend this technology to suboptimal input DNA conditions, including ultra-low input down to single cells. DNA preamplification significantly enhanced detection rates to over 50% in five-cell samples and ∼25% in single cells. Enzymatic conversion also substantially improved data quality. Computationally, we developed a method to model the background signal's influence on the DNA methylation level readings. The modified detection P-value calculation achieved higher sensitivities for low-input datasets and was validated in over 100 000 public diverse methylome profiles. We employed the optimized workflow to query the demethylation dynamics in mouse primordial germ cells available at low cell numbers. Our data revealed nuanced chromatin states, sex disparities, and the role of DNA methylation in transposable element regulation during germ cell development. Collectively, we present comprehensive experimental and computational solutions to extend this widely used methylation assay technology to applications with limited DNA.

BISCUIT: an efficient, standards-compliant tool suite for simultaneous genetic and epigenetic inference in bulk and single-cell studies

Data from both bulk and single-cell whole-genome DNA methylation experiments are under-utilized in many ways. This is attributable to inefficient mapping of methylation sequencing reads, routinely discarded genetic information, and neglected read-level epigenetic and genetic linkage information. We introduce the BISulfite-seq Command line User Interface Toolkit (BISCUIT) and its companion R/Bioconductor package, biscuiteer, for simultaneous extraction of genetic and epigenetic information from bulk and single-cell DNA methylation sequencing. BISCUIT's performance, flexibility and standards-compliant output allow large, complex experimental designs to be characterized on clinical timescales. BISCUIT is particularly suited for processing data from single-cell DNA methylation assays, with its excellent scalability, efficiency, and ability to greatly enhance mappability, a key challenge for single-cell studies. We also introduce the epiBED format for single-molecule analysis of coupled epigenetic and genetic information, facilitating the study of cellular and tissue heterogeneity from DNA methylation sequencing.

Inflammatory and tissue injury marker dynamics in pediatric acute respiratory distress syndrome

BACKGROUND

The molecular signature of pediatric acute respiratory distress syndrome (ARDS) is poorly described, and the degree to which hyperinflammation or specific tissue injury contributes to outcomes is unknown. Therefore, we profiled inflammation and tissue injury dynamics over the first 7 days of ARDS, and associated specific biomarkers with mortality, persistent ARDS, and persistent multiple organ dysfunction syndrome (MODS).

METHODS

In a single-center prospective cohort of intubated pediatric ARDS, we collected plasma on days 0, 3, and 7. Nineteen biomarkers reflecting inflammation, tissue injury, and damage associated molecular patterns were measured. We assessed the relationship between biomarkers and trajectories with mortality, persistent ARDS, or persistent MODS using multivariable mixed effect models.

RESULTS

In 279 subjects (64 [23%] non-survivors), hyperinflammatory cytokines, tissue injury markers, and DAMPs were higher in non-survivors. Survivors and non-survivors showed different biomarker trajectories. IL-1α, sTNFR1, ANG2, and SPD increased in non-survivors, while DAMPs remained persistently elevated. ANG2 and P3NP were associated with persistent ARDS, whereas multiple cytokines, tissue injury markers, and DAMPs were associated with persistent MODS. Corticosteroid use did not impact the association of biomarker levels or trajectory with mortality.

CONCLUSIONS

Pediatric ARDS survivors and non-survivors had distinct biomarker trajectories, with cytokines, endothelial and alveolar epithelial injury, and DAMPs elevated in non-survivors. Mortality markers overlapped with markers associated with persistent MODS, rather than persistent ARDS.

Strictureplasty may lead to increased preference in the surgical management of Crohn's disease: a case-matched study

BACKGROUND

Resection and strictureplasty are the two surgical modalities used in the management of Crohn's disease (CD). The objective of this study was to compare morbidity and clinical recurrence between patients who underwent strictureplasty and patients who underwent resection.

METHODS

Patients with CD who underwent strictureplasty between January 2012 and December 2022 were enrolled. The patients were well matched with patients who underwent resection without strictureplasty. Patient- and disease-specific characteristics, postoperative morbidity, and clinical recurrence were also analyzed.

RESULTS

A total of 118 patients who underwent a total of 192 strictureplasties were well matched to 118 patients who underwent resection. The strictureplasty group exhibited significantly less blood loss (30 ml versus 50 ml, p < 0.001) and stoma creation (2.5% versus 16.9%, p < 0.001). No significant difference was found regarding postoperative complications or length of postoperative stay. At the end of the follow-up, the overall rate of clinical recurrence was 39.4%, and no difference was observed between the two groups. Postoperative prophylactic use of biologics (odds ratio = 0.2, p < 0.001) was the only protective factor against recurrence.

CONCLUSION

Strictureplasty does not increase the risk of complications or recurrence compared with resection. It represents a viable alternative to resection in selected patients, and as such, it should have a broader scope of indications and greater acceptance among surgeons.

A signal processing and deep learning framework for methylation detection using Oxford Nanopore sequencing

Oxford Nanopore sequencing can detect DNA methylations from ionic current signal of single molecules, offering a unique advantage over conventional methods. Additionally, adaptive sampling, a software-controlled enrichment method for targeted sequencing, allows reduced representation methylation sequencing that can be applied to CpG islands or imprinted regions. Here we present DeepMod2, a comprehensive deep-learning framework for methylation detection using ionic current signal from Nanopore sequencing. DeepMod2 implements both a bidirectional long short-term memory (BiLSTM) model and a Transformer model and can analyze POD5 and FAST5 signal files generated on R9 and R10 flowcells. Additionally, DeepMod2 can run efficiently on central processing unit (CPU) through model pruning and can infer epihaplotypes or haplotype-specific methylation calls from phased reads. We use multiple publicly available and newly generated datasets to evaluate the performance of DeepMod2 under varying scenarios. DeepMod2 has comparable performance to Guppy and Dorado, which are the current state-of-the-art methods from Oxford Nanopore Technologies that remain closed-source. Moreover, we show a high correlation (r = 0.96) between reduced representation and whole-genome Nanopore sequencing. In summary, DeepMod2 is an open-source tool that enables fast and accurate DNA methylation detection from whole-genome or adaptive sequencing data on a diverse range of flowcell types.

UHRF1 ubiquitin ligase activity supports the maintenance of low-density CpG methylation

The RING E3 ubiquitin ligase UHRF1 is an established cofactor for DNA methylation inheritance. Nucleosomal engagement through histone and DNA interactions directs UHRF1 ubiquitin ligase activity toward lysines on histone H3 tails, creating binding sites for DNMT1 through ubiquitin interacting motifs (UIM1 and UIM2). Here, we profile contributions of UHRF1 and DNMT1 to genome-wide DNA methylation inheritance and dissect specific roles for ubiquitin signaling in this process. We reveal DNA methylation maintenance at low-density CpGs is vulnerable to disruption of UHRF1 ubiquitin ligase activity and DNMT1 ubiquitin reading activity through UIM1. Hypomethylation of low-density CpGs in this manner induces formation of partially methylated domains (PMD), a methylation signature observed across human cancers. Furthermore, disrupting DNMT1 UIM2 function abolishes DNA methylation maintenance. Collectively, we show DNMT1-dependent DNA methylation inheritance is a ubiquitin-regulated process and suggest a disrupted UHRF1-DNMT1 ubiquitin signaling axis contributes to the development of PMDs in human cancers.

Biomechanical and aesthetic outcomes following radial forearm free flap transfer: comparison of ipsilateral full-thickness skin graft and traditional split-thickness skin graft

The radial forearm free flap (RFFF) is associated with donor site morbidity. This study aimed to quantify the functional and aesthetic outcomes after closure of the RFFF donor site using triangular full-thickness skin grafts (FTSGs) harvested adjacent to the flap or traditional split-thickness skin grafts (STSGs). The study included patients who underwent oral cavity reconstruction with an RFFF between March 2017 and August 2021. The patients were divided into two groups based on the donor site closure method: FTSG or STSG. The primary outcomes were biomechanical grip strength, pinch strength, and range of wrist movements. Subjective donor site morbidity, aesthetic and functional results were also analysed. The study included 75 patients (FTSG n = 35; STSG n = 40). Postoperatively, there was a statistically significant difference in grip strength (P = 0.049) and wrist extension (P = 0.047) between the FTSG and STSG groups, in favour of the STSG. Differences between the groups in pinch strength and other wrist motions were not statistically significant. The harvesting time was significantly shorter for the FTSG (P = 0.041) and the appearance of the donor site was better (P = 0.026) when compared to the STSG. Cold intolerance was more frequent in the STSG group (32.5% STSG vs 6.7% FTSG; P = 0.017). Subjective function, numbness, pain, hypertrophic scar, itching, and social stigma did not differ significantly between the groups. Compared with the STSG, the FTSG showed better cosmesis and avoided additional donor sites, with clinically negligible differences in hand biomechanics.

Fish diversity and selection of taxa for conservation in the Salween and Irrawaddy Rivers, Southeast Asia

Species diversity indices provide quantitative data for understanding the variations and trends in fish species diversity, as well as information on species richness and evenness. However, these diversity indices do not reflect differences in specific taxa, which can be of importance as key conservation targets, especially during the planning and construction of protected areas. In this study, simultaneously combining our improved traditional fish fauna analysis (TFFA) with the value of fish fauna presence (VFFP) methods, we studied fish diversity in the Salween and Irrawaddy basins. The results of the TFFA reflected the families (subfamilies) and genera that constitute the main body of fish diversity in the river basins. The results of the VFFP assessment showed which families (subfamilies) and genera were representative of certain characteristics in the basins. The VFFP scores of genera could be used as indicator indices and as priority taxa in the planning and construction of fish resource reserves. In this paper, we propose for the first time that the role and status of monotypic genera (genera comprising only a single species) in the conservation of fish diversity should not be ignored, and they should rather be a priority for protection.

Creation and Validation of the First Infinium DNA Methylation Array for the Human Imprintome

Background

Differentially methylated imprint control regions (ICRs) regulate the monoallelic expression of imprinted genes. Their epigenetic dysregulation by environmental exposures throughout life results in the formation of common chronic diseases. Unfortunately, existing Infinium methylation arrays lack the ability to profile these regions adequately. Whole genome bisulfite sequencing (WGBS) is the unique method able to profile these regions, but it is very expensive and it requires not only a high coverage but it is also computationally intensive to assess those regions.

Findings

To address this deficiency, we developed a custom methylation array containing 22,819 probes. Among them, 9,757 probes map to 1,088 out of the 1,488 candidate ICRs recently described. To assess the performance of the array, we created matched samples processed with the Human Imprintome array and WGBS, which is the current standard method for assessing the methylation of the Human Imprintome. We compared the methylation levels from the shared CpG sites and obtained a mean R 2 = 0.569. We also created matched samples processed with the Human Imprintome array and the Infinium Methylation EPIC v2 array and obtained a mean R 2 = 0.796. Furthermore, replication experiments demonstrated high reliability (ICC: 0.799-0.945).

Conclusions

Our custom array will be useful for replicable and accurate assessment, mechanistic insight, and targeted investigation of ICRs. This tool should accelerate the discovery of ICRs associated with a wide range of diseases and exposures, and advance our understanding of genomic imprinting and its relevance in development and disease formation throughout the life course.

Regional variations in retinopathy of prematurity incidence for preterm infants <32 weeks' gestation in China

OBJECTIVES

National-level data on the incidence of retinopathy of prematurity (ROP) in different regions of China is insufficient. This study aimed to compare ROP incidences and care practices in different regions of China and their relationship with regional gross domestic product (GDP) per capita.

STUDY DESIGN

Retrospective cohort study.

METHODS

All infants born at <32 weeks gestational age (GA) and admitted to 70 neonatal intensive care units (NICUs) from January 1, 2019, to December 31, 2020, were enrolled. Hospitals were categorised into three regional groups according to geographical locations and GDP per capita from high to low: Eastern, Central, and Western China. The incidence of death or ROP, and care practices were compared among the groups.

RESULTS

A total of 18,579 infants were enrolled. Median GA was 29.9 (interquartile range 28.4-31.0) weeks and birth weight was 1318.1 (317.2) g. The percentage of GA <28 weeks, complete administration of antenatal steroids, and weight gain velocity during NICU stay were highest in Eastern China and lowest in Western China (all P < 0.01). In Eastern, Central, and Western China, the rates of death or any stage of ROP were 33.3%, 38.5%, and 39.2%, respectively (P < 0.01).

CONCLUSIONS

There were considerable regional disparities in ROP incidence in preterm infants with GA <32 weeks in China. The incidence of death or ROP ranged from high to low in Western, Central, and Eastern China.

Higher Cognitive Reserve Is Beneficial for Cognitive Performance Via Various Locus Coeruleus Functional Pathways in the Pre-Dementia Stage of Alzheimer's Disease

BACKGROUND

Cognitive reserve (CR) shows protective effects on cognitive function in older adult and in Alzheimer's disease (AD). However, the brain mechanisms underlying the CR effect on the non-dementia AD spectrum (subjective cognitive decline (SCD) and mild cognitive impairment (MCI)) are unknown. The aim of this study was to investigate the potential moderate effect of CR on brain functional networks associated with cognitive performance.

METHODS

We selected 200 participants, including 48 cognitively normal (CN) and 56 SCD, and 96 patients with MCI from the Alzheimer's Disease Neuroimaging Initiative (ADNI). Seed-based locus coeruleus functional connectivity (LC FC) was conducted to detect early brain functional changes in the non-dementia AD spectrum. CR was assessed via years of education and intelligence (IQ). The ANDI composite executive function scores (ADNI-EF) and ADNI composite memory scores (ANDI-MEM) at baseline and 24-month follow-up were used to assess cognitive performance.

RESULTS

Compared to the CN group, the SCD group showed abnormal LC FC with the executive control network (dorsolateral prefrontal cortex, DLPFC), salience network, sensorimotor network, reward network, and hippocampus, while these alterations were inverted at the MCI stage. The LC-hippocampus FC was correlated with ADNI-MEM at baseline and follow-up, and these relationships were moderated by education. The LC-DLPFC FC was correlated with ADNI-EF at baseline, and this association was moderated by IQ.

CONCLUSION

Our results manifested that higher levels of CR would confer protective effects on SCD and MCI. Furthermore, IQ and education could moderate the relationship between LC FC and cognition through different pathways.

Health inequalities of global protein-energy malnutrition from 1990 to 2019 and forecast prevalence for 2044: data from the Global Burden of Disease Study 2019

OBJECTIVES

Protein-energy malnutrition poses a serious medical problem worldwide. This study aims to describe the global burden, trends, and health inequalities of protein-energy malnutrition and forecasts for future prevalence.

STUDY DESIGN

This was a comprehensive analysis based on data provided by the Global Burden of Disease Study 2019.

METHODS

Data were obtained from the Global Health Data Exchange query tool, including prevalence, deaths, disability-adjusted life years (DALYs) and sociodemographic index (SDI). The estimated annual percentage changes were calculated to evaluate temporal trends. We quantified cross-country inequalities in protein-energy malnutrition burden and predicted the prevalence number and rate to 2044.

RESULTS

Globally, there were 147,672,757 (130,405,923 to 167,471,359) cases of protein-energy malnutrition in 2019, with 212,242 (185,403 to 246,217) deaths. Eastern Sub-Saharan Africa had the highest age-standardised death and DALY rates in 2019. From 1990 to 2019, the global age-standardised prevalence rate of protein-energy malnutrition showed an upward trend, while the age-standardised death rate showed a downward trend. A significant decline occurred in SDI-related health inequality, from 2126.1 DALYs per 100,000 persons between the poorest and richest countries in 1990 to 357.9 DALYs per 100,000 persons in 2019. There was a trend of decreasing age-standardised death and DALY rates along with increases in the SDI. Frontier analyses showed that there is much room for improving the current situation of protein-energy malnutrition in some countries. In the next 35 years, the prevalence of protein-energy malnutrition will continue to increase.

CONCLUSION

Although the disease burden of protein-energy malnutrition has greatly decreased since 1990 and health inequalities between countries are shrinking, the prevalence in Asian and African countries may continue to increase. Focussing on regional differences and strengthening the nutritional intake of people in underdeveloped areas are necessary to reduce future burdens.

Enhanced Bonding to Caries-Affected Dentin Using an Isocyanate-Based Primer

Dental caries is the most common oral disease and the most common cause of resin restorations. In minimally invasive dentistry, the principle behind cavity preparation is to remove external caries-infected dentin (CID) and preserve internal caries-affected dentin (CAD) and sound dentin (SD). The cavity floor is mainly composed of CAD, but the poor bonding performance of CAD has become a widespread concern. This study evaluated the performance of a new collagen-reactive monomer (ITCM) used as a primer to improve the bonding performance of CAD. The experimental specimens were grouped as follows: SD, CAD, and ITCM-pretreated CAD (CAD-ITCM). Dentin slices were obtained for attenuated total reflectance-Fourier transform infrared (ATR-FTIR) analysis. The bonded samples were subjected to microtensile bond strength analysis after 24 h of water storage or aging by thermocycling, and the bonding interface quality was evaluated by nanoleakage assessment, interfacial nanoindentation testing, and in situ zymography. Cytotoxicity experiments with ITCM were performed. ATR-FTIR showed that the isocyanate groups in ITCM can covalently bind and form hydrogen bonds with the collagen in CAD to mediate chemical bonding. ITCM pretreatment significantly improved the bond strength of CAD (P < 0.05), reduced interfacial nanoleakage, improved the sealing of the bonding interface, enhanced the homogeneity of the hybrid layer, and inhibited matrix metalloproteinase activity. In addition, ITCM presented acceptable biocompatibility for dental restorative application. Taken together, this study reported the application of ITCM to induce collagen-based chemical bonding in the CAD bonding system, which fills the gap in strategies to improve the bonding performance of CAD immediately and after aging and has important clinical application prospects.

American Heart Association's new 'Life's Essential 8' score in association with cardiovascular disease: a national cross-sectional analysis

OBJECTIVE

The American Heart Association (AHA) has recently updated and enhanced the quantification of cardiovascular health by using the Life's Essential 8 (LE8) score. We intended to examine the correlation between cardiovascular health status, as measured by the new LE8 score, and cardiovascular disease (CVD) in US adults.

STUDY DESIGN

National cross-sectional study.

METHODS

A total of 24,730 individuals without pregnancy and with complete data from 2007 to 2018 enrolled in the study. The overall LE8 score was divided into low, moderate, and high groups. Multivariate logistic regressions were used to assess the odds ratios (ORs) and 95% confidence intervals (CIs) for the associations between the LE8 score and the presence of CVD.

RESULTS

Overall, the high LE8 group had a younger age (20-59 years, 82.95%) and more females (60.09%) compared to the low LE8 group. Moderate and high LE8 correlated negatively with the presence of CVD (moderate, OR: 0.46, 95% CI: 0.39-0.54; high, OR: 0.26, 95% CI: 0.21-0.33). One standard deviation increment in the LE8 score correlated significantly with lower odds of CVD (OR: 0.64; 95% CI: 0.60-0.69). Further stratification analysis also detected a significant relationship between the new LE8 score and CVD, and the result was enhanced among the young and women (P-interaction<0.001).

CONCLUSIONS

Higher LE8 score correlated with lower odds of CVD, especially among the young and women.

Dupsifter: a lightweight duplicate marking tool for whole genome bisulfite sequencing

SUMMARY

In whole genome sequencing data, polymerase chain reaction amplification results in duplicate DNA fragments coming from the same location in the genome. The process of preparing a whole genome bisulfite sequencing (WGBS) library, on the other hand, can create two DNA fragments from the same location that should not be considered duplicates. Currently, only one WGBS-aware duplicate marking tool exists. However, it only works with the output from a single tool, does not accept streaming input or output, and requires a substantial amount of memory relative to the input size. Dupsifter provides an aligner-agnostic duplicate marking tool that is lightweight, has streaming capabilities, and is memory efficient.

AVAILABILITY AND IMPLEMENTATION

Source code and binaries are freely available at https://github.com/huishenlab/dupsifter under the MIT license. Dupsifter is implemented in C and is supported on macOS and Linux.

[Pelvic coronal inclination change in adolescent flexible flatfoot surgically treated with arthroereisis]

Objective: To evaluate adolescent pelvic coronal inclination angle change after flatfoot treated with arthroereisis. Method: A case-series study. From June 2018 to September 2020, 25 children with flexible flat foot and pelvic obliquity were included in this retrospective study in Peking University Shenzhen Hospital. There were 17 males and 8 females with a mean age of (11.2±2.2) years (9-15 years). There were 5 cases of unilateral flatfoot and 20 cases of bilateral flatfoot. All of the patients were surgically treated with arthroereisis. Regular follow-up was done in 3 months, 1 and 2 years postoperatively. Weightbearing fluoroscopy of entire lower limb and foot were investigated to measure Meary's angle, calcaneal pitch angle, height difference at ankle and pelvic plane, pelvic inclination and sacrum-iliac distance (F value) on coronal plane. Results: The mean Mearys' angle at 3 month postoperatively was improved when compared with that before the operation (3.1°±1.5° vs 25.9°±4.3°, P<0.001), and it remained at the same level 2 years after the operation (compared with that at 1 year after the operation, P=0.748). The calcaneal pitch angle improved significantly at 3-month follow-up when compared with that before the operation (16.6°±2.4° vs 9.9°±1.5°, P<0.001), and there was no significant change between 1 year and 2 years after operation (P=0.542). The height difference at mortise plane were also reduced at the 3-month follow-up(P<0.001), and it remained at the same level at 1 year and 2 years after the operation (P=0.159). Pelvic height difference decreased dramatically from (12.4±1.7) mm (before operation) to (7.1±1.2) mm(3 month after the operation) (P<0.001), it decreased to (3.6±1.8) mm 1 year after the operation (compared with that at 3 months after the operation, P<0.001), and no further reduction was observed 2 years after the surgery (P=0.483). The pelvic inclination angle and sacrum-iliac distance were also improved at 3-month follow-up when compared with those before the operation (both P<0.001), and they declined further 1 year after the operation(both P<0.05), but the decreasing trend disappeared at the 2-year follow-up (both P>0.05). Conclusion: For adolescent flexible flat foot patients with pelvic obliquity, the coronal inclination and pelvic height discrepancy would partially recovered with correction of flatfoot deformity, but it could not be completely corrected in the mean follow-up period of 2 years after the operation.

A Retrospective Analysis of Immediate Postoperative Electron Radiotherapy for Keloids

PURPOSE/OBJECTIVE(S)

The increasing incidence of keloid has seriously affected people's physical and mental health, and the postoperative recurrence rate is as high as 50-80%. Postoperative radiotherapy has been shown to significantly reduce the recurrence of keloid. Given the different treatment patterns in different institutions, we tried to analyze the data of patients in our center.

MATERIALS/METHODS

We retrospectively analyzed the clinical data of 455 patients with 498 keloids treated in our institution from 2010 to 2017. All patients received a four-fraction electron radiotherapy with single dose of 4 Gy within 24 hours of surgery. The recurrence and adverse reaction of immediate adjuvant radiotherapy in these patients was evaluated.

RESULTS

At the last follow-up date, 130 (26.5%) keloids had recurred after a middle follow-up of 68.1 months (42.6-129.9 months). The recurrence rates of 1 year, 3 years and 5 years were respectively14.5%, 18.7% and 21%. Recurrence rates vary depending on the keloid location. Among them, the recurrence rate of ear was low with 14% (43/298). Face, head neck and limbs was moderate with 38.8% (17/44) and 33.3% (8/24). Chest and Suprapubic region had a high recurrence rate of 50.8% (32/64) and 47.8% (33/69). Among the patients with recurrence, 16.9% (22/130) felt that their symptoms were better than before treatment, and 37.7% (49/130) were not worsen, which was acceptable. Multivariate analysis showed that age and duration of postoperative pruritus pain were correlated with recurrence (P = 0.036; P = 0.02). Radiotherapy combined with steroid and silicone reduced the recurrence rate compared with radiotherapy alone (P = 0.015). During treatment and follow-up, Infection occurred in 2 patients and cutaneous fibroblastoma in 1 patient.

CONCLUSION

Our radiotherapy regimen can effectively reduce the recurrence rate and improve the symptoms of patients with keloids, especially ear keloids. High recurrence sites need further improvement of radiotherapy dose and fraction. Combination of multiple treatments is better than single treatment.

Early Stereotactic Body Radiotherapy to the Primary Lung Lesion for Patients with Advanced NSCLC Treated with First-Line Systemic Therapy

PURPOSE/OBJECTIVE(S)

Although adding consolidative stereotactic body radiotherapy (SBRT) to systemic therapy improves survival in advanced non-small cell lung cancer (NSCLC), the optimal timing of SBRT remains unclear. This study aimed to explore the clinical outcome of early and delayed SBRT to primary lung lesions of advanced NSCLC patients treated with first-line systemic therapy.

MATERIALS/METHODS

We identified patients with advanced NSCLC who were suitable to receiveSBRT for the primary lung tumors after first-line systemic therapy. All eligible patients were treated with first-line systemic therapy and SBRT for their primary lung lesions. Early SBRT group was defined as patients who received SBRT for their primary lung tumor at the maximal response of systemic therapy. Delayed SBRT group was defined as patients who received SBRT after the occurrence of oligoprogression in primary lung tumor. The primary endpoints were progression-free survival 1 (PFS1, time from start of first-line systemic therapy to disease progression) and PFS2 (time from start of first-line systemic therapy to disease progression after SBRT). Overall survival (OS) and adverse effects (AEs) were secondary endpoints. A two-sided P value of 0.05 was considered statistically significant. All of the statistical analyses were performed with statistical software.

RESULTS

A total of184 patients with advanced NSCLC treated with SBRT for primary tumors were screened, and 49 patients were eligible for enrollment in this study. The median age of the entire cohort was 66 years (range, 37-80 years), and 34 (69.4%) patients were male. Thirty-four patients (69.4%) were treated by target therapy and 15 (30.6%) were treated by chemotherapy and immunotherapy. Of the 49 eligible patients, 28(57.1%) received early SBRT to lung primary tumor and 21(42.9%) received delayed SBRT to lung primary tumor. The early SBRT group showed a significantly prolonged PFS1 as compared with the delayed SBRT group (mPFS1: 30 months vs. 8 months, P<0.001). The median PFS2 of the early SBRT group was longer than that of the delayed SBRT group, but the difference between the two groups did not achieve a statistical significance (mPFS2: 42 months vs. 23 months, P = 0.303). Median OS of both groups has not reached. No severe toxicities (≥grade 3) were observed in early SBRT group and only one patient in the delayed SBRT group experienced grade 3 radiation pneumonitis.

CONCLUSION

Early SBRT to the primary lung lesion significantly improved PFS and is a new potentially effective and tolerable treatment option for patients with advanced NSCLC who had stable disease during first-line systemic therapy.

Comprehensive Evaluation of The Infinium Human MethylationEPIC v2 BeadChip

Infinium Methylation BeadChips are widely used to profile DNA cytosine modifications in large cohort studies for reasons of cost-effectiveness, accurate quantification, and user-friendly data analysis in characterizing these canonical epigenetic marks. In this work, we conducted a comprehensive evaluation of the updated Infinium MethylationEPIC v2 BeadChip (EPICv2). Our evaluation revealed that EPICv2 offers significant improvements over its predecessors, including expanded enhancer coverage, applicability to diverse ancestry groups, support for low-input DNA down to one nanogram, coverage of existing epigenetic clocks, cell type deconvolution panels, and human trait associations, while maintaining accuracy and reproducibility. Using EPICv2, we were able to identify epigenome and sequence signatures in cell line models of DNMT and SETD2 loss and/or hypomorphism. Furthermore, we provided probe-wise evaluation and annotation to facilitate the use of new features on this array for studying the interplay between somatic mutations and epigenetic landscape in cancer genomics. In conclusion, EPICv2 provides researchers with a valuable tool for studying epigenetic modifications and their role in development and disease.

Low-input and single-cell methods for Infinium DNA methylation BeadChips

The Infinium BeadChip is the most widely used DNA methylome assay technology for population-scale epigenome profiling. However, the standard workflow requires over 200 ng of input DNA, hindering its application to small cell-number samples, such as primordial germ cells. We developed experimental and analysis workflows to extend this technology to suboptimal input DNA conditions, including ultra-low input down to single cells. DNA preamplification significantly enhanced detection rates to over 50% in five-cell samples and ∼25% in single cells. Enzymatic conversion also substantially improved data quality. Computationally, we developed a method to model the background signal's influence on the DNA methylation level readings. The modified detection p -values calculation achieved higher sensitivities for low-input datasets and was validated in over 100,000 public datasets with diverse methylation profiles. We employed the optimized workflow to query the demethylation dynamics in mouse primordial germ cells available at low cell numbers. Our data revealed nuanced chromatin states, sex disparities, and the role of DNA methylation in transposable element regulation during germ cell development. Collectively, we present comprehensive experimental and computational solutions to extend this widely used methylation assay technology to applications with limited DNA.

Universal DNA methylation age across mammalian tissues

Aging, often considered a result of random cellular damage, can be accurately estimated using DNA methylation profiles, the foundation of pan-tissue epigenetic clocks. Here, we demonstrate the development of universal pan-mammalian clocks, using 11,754 methylation arrays from our Mammalian Methylation Consortium, which encompass 59 tissue types across 185 mammalian species. These predictive models estimate mammalian tissue age with high accuracy (r > 0.96). Age deviations correlate with human mortality risk, mouse somatotropic axis mutations and caloric restriction. We identified specific cytosines with methylation levels that change with age across numerous species. These sites, highly enriched in polycomb repressive complex 2-binding locations, are near genes implicated in mammalian development, cancer, obesity and longevity. Our findings offer new evidence suggesting that aging is evolutionarily conserved and intertwined with developmental processes across all mammals.

DNA methylation networks underlying mammalian traits

Using DNA methylation profiles (n = 15,456) from 348 mammalian species, we constructed phyloepigenetic trees that bear marked similarities to traditional phylogenetic ones. Using unsupervised clustering across all samples, we identified 55 distinct cytosine modules, of which 30 are related to traits such as maximum life span, adult weight, age, sex, and human mortality risk. Maximum life span is associated with methylation levels in HOXL subclass homeobox genes and developmental processes and is potentially regulated by pluripotency transcription factors. The methylation state of some modules responds to perturbations such as caloric restriction, ablation of growth hormone receptors, consumption of high-fat diets, and expression of Yamanaka factors. This study reveals an intertwined evolution of the genome and epigenome that mediates the biological characteristics and traits of different mammalian species.

PyComplexHeatmap: a Python package to visualize multimodal genomics data

Python has emerged as a robust programming language increasingly employed in genomics data analysis, largely due to its comprehensive deep learning libraries and proficiency in handling large-scale data, such as single-cell multi-omics datasets. Although Python has become a prominent data science ecosystem for bioinformatics, there remains a growing demand for advanced heatmap visualization and assembly tools, which are not sufficiently addressed by existing Python-based data visualization libraries. We present PyComplexHeatmap, an all-inclusive Python library for heatmap visualization, inspired by the ComplexHeatmap package currently available in R. PyComplexHeatmap is built upon the matplotlib library and features a versatile, modular interface that seamlessly integrates with other Python-based data science tools, such as Pandas, NumPy, and genomics tools, such as Scanpy, in a standard-compliant manner. This library caters to the requirements of exquisite rendering of multimodal matrix data, incorporating both textual and graphical annotations, thereby enabling efficient integrative analysis of multimodal data and associated metadata.

Association of edentulism and all-cause mortality in Chinese older adults: do sex differences exist?

OBJECTIVES

Previous studies revealed that tooth loss or edentulism was related to mortality. However, research in developing countries with large numbers of elderly populations is rare, and whether sex differences exist in this relationship is unknown. This study aimed to investigate the association between edentulism and 7-year all-cause mortality among older adults in China and whether sex differences existed.

STUDY DESIGN

This was a prospective cohort study.

METHODS

Data were from 2011 to 2018 waves of the China Health and Retirement Longitudinal Study. A total of 6538 participants aged ≥60 years were included. Logistic models were adopted to estimate the risks of mortality according to edentulism.

RESULTS

The participants with edentulism at baseline were 20% more likely to die over 7 years after controlling for a set of covariates (odds ratio [OR] = 1.20, 95% confidence interval [CI]: 1.02-1.42). Moreover, edentulism was associated with a 35% higher odds of death among male participants (OR = 1.35, 95% CI: 1.08-1.70), whereas a significant association was not found in female participants.

CONCLUSIONS

The findings demonstrated that baseline edentulism predicted all-cause mortality in Chinese older adults, and sex differences existed in this association. This study implied the importance of developing oral health education programs, incorporating dietary recommendations into dental care for edentulous patients, and expanding the coverage of dental services in the health insurance system to prevent edentulism and alleviate its negative outcomes for older adults.

[The design method of the digital sequential tooth-sectioning guide for the extraction of mandibular impacted third molars]

Objective: To explore a method for digitally designing and fabricating a sequential tooth-sectioning guide that can assist in the extraction of mandibular horizontal impacted third molars, preliminarily evaluate its feasibility and provide a reference for clinical application. Methods: Twenty patients with mandibular low level impacted third molars who visited the Department of General Dentistry, Peking University School and Hospital of Stomatology from March 2021 to January 2022 were selected. Cone-beam CT showed direct contact between the roots and mandibular canal, and full range impressions of the patients' intraoral teeth were taken and optical scans of the dental model were performed. The patients' cone-beam CT data and optical scan data were reconstructed in three dimensions, anatomical structure extraction, registration fusion, and the design of the structure of the guide (including crown-sectioning guide and root-sectioning guide) by Mimics 24.0, Geomagic Wrap 2021, and Magics 21.0 software, and then the titanium guide was three dimension printed, and the guide was tried on the dental model. After confirmation, the guide was used to assist the dentist in the operation. We observed whether the guide was in place, the number of tooth splitting, the matching of tooth splitting with the preoperative design, the operation time, and whether there were any complications. Results: In this study, 20 sectioning guides were successfully printed, all of them were well fitted in the patients' mouth, the average number of section was 3.4 times, the tooth parts was better matched with the preoperative design, and the average operative time of the guides was (29.2±9.8) minutes without complications such as perforation of the bone cortex. Conclusions: The use of sequential sectioning guides to assist in the extraction of mandibular impacted third molars was initially validated to accurately replicate the preoperative sectioning design, and is expected to provide a digital solution to improve surgical precision and ensure safety. Further studies with larger sample sizes are needed to evaluate its accuracy and safety.

[Mechanisms mediating the inhibitory effects of quercetin against phthalates-induced testicular oxidative damage in rats]

OBJECTIVE

To explore the mechanism underlying the inhibitory effect of quercetin against testicular oxidative damage induced by a mixture of 3 commonly used phthalates (MPEs) in rats.

METHODS

Forty male Sprague-Dawley rats were randomly divided into control group, MPEs exposure group, and MPEs with low-, median- and high-dose quercetin treatment groups. For MPEs exposure, the rats were subjected to intragastric administration of MPEs at the daily dose of 900 mg/kg for 30 consecutive days; Quercetin treatments were administered in the same manner at the daily dose of 10, 30, and 90 mg/kg. After the treatments, serum levels of testosterone, luteinizing hormone (LH), follicle stimulating hormone (FSH), and testicular malondialdeyhde (MDA), catalase (CAT) and superoxide dismutase (SOD) were detected, and testicular pathologies of the rats were observed with HE staining. The expressions of nuclear factor-E2-related factor 2 (Nrf2), Kelch-like ECH2 associated protein 1 (Keap1) and heme oxygenase 1 (HO-1) in the testis were detected using immunofluorescence assay and Western blotting.

RESULTS

Compared with the control group, the rats with MPEs exposure showed significant reductions of the anogenital distance, weight of the testis and epididymis, and the coefficients of the testis and epididymis with lowered serum testosterone, LH and FSH levels (P < 0.05). Testicular histological examination revealed atrophy of the seminiferous tubules, spermatogenic arrest, and hyperplasia of the Leydig cells in MPEs-exposed rats. MPEs exposure also caused significant increments of testicular Nrf2, MDA, SOD, CAT and HO-1 expressions and lowered testicular Keap1 expression (P < 0.05). Treatment with quercetin at the median and high doses significantly ameliorated the pathological changes induced by MPEs exposure (P < 0.05).

CONCLUSION

Quercetin treatment inhibits MPEs-induced oxidative testicular damage in rats possibly by direct scavenging of free radicals to lower testicular oxidative stress and restore the regulation of the Nrf2 signaling pathway.

Comparative epigenome analysis using Infinium DNA methylation BeadChips

The arrival of the Infinium DNA methylation BeadChips for mice and other nonhuman mammalian species has outpaced the development of the informatics that supports their use for epigenetics study in model organisms. Here, we present informatics infrastructure and methods to allow easy DNA methylation analysis on multiple species, including domesticated animals and inbred laboratory mice (in SeSAMe version 1.16.0+). First, we developed a data-driven analysis pipeline covering species inference, genome-specific data preprocessing and regression modeling. We targeted genomes of 310 species and 37 inbred mouse strains and showed that genome-specific preprocessing prevents artifacts and yields more accurate measurements than generic pipelines. Second, we uncovered the dynamics of the epigenome evolution in different genomic territories and tissue types through comparative analysis. We identified a catalog of inbred mouse strain-specific methylation differences, some of which are linked to the strains' immune, metabolic and neurological phenotypes. By streamlining DNA methylation array analysis for undesigned genomes, our methods extend epigenome research to broad species contexts.

Interactive Effects of Dietary Inflammatory Index with BMI for the Risk of Stroke among Adults in the United States: Insight from NHANES 2011-2018

BACKGROUND AND AIM

Research on the correlation between Dietary Inflammation Index (DII) and stroke is limited. Patients with high body mass index (BMI), as a high-risk group for stroke, require attention. Therefore, we aimed to examine the interactive effects of dietary inflammation and BMI on the risk of stroke among adults in the United States.

METHODS AND RESULTS

Overall, 9,384 participants were included in this study. The exposure variable was the DII, which was calculated based on the overall inflammatory effect score, and the outcome was stroke. Overall, there was a positive relationship between DII (as a continuous variable) and stroke. Increased level of DII was significantly associated with increased risk of stroke (odds ratio [OR]: 1.21, 95% CI: 1.06-1.38), which was enhanced by higher BMI (OR: 1.35, 95% CI: 1.15-1.58) with significant additive interactions. There was a significant secondary interaction of copresence of BMI ≥25 kg/m2, systolic blood pressure (SBP) ≥140 mmHg, and high DII for increased stroke, with a further increase in OR to 1.41 (1.19-1.67).

CONCLUSIONS

This cross-sectional study shows that the relationship between higher DII levels and the significant increase in stroke prevalence was further amplified in patients with SBP ≥140 mmHg and higher BMI.

Global Prevalence and Factors Associated with Frailty among Community-Dwelling Older Adults with Hypertension: A Systematic Review and Meta-Analysis

BACKGROUND

Frailty may increase the risk of adverse outcomes and the presence of comorbidities in hypertension. Understanding the prevalence of frailty in older adults with hypertension is of great importance, whereas estimates of the prevalence of frailty in this population vary greatly.

OBJECTIVES

A systematic review and meta-analysis was conducted to estimate the pooled prevalence of frailty and prefrailty among community-dwelling older adults with hypertension, and to examine the risk factors associated with (pre)frailty in this population.

METHODS

PubMed, Web of Science, The Cochrane Library, EMBASE, and CINAHL were searched from the inception to May 10, 2023. Investigators assessed eligibility, extracted data, and evaluated methodological quality. The pooled prevalence of frailty and prefrailty was calculated using the random-effects model. Meta-regression analysis and subgroup analysis were conducted to explore sources of heterogeneity. Sensitivity analysis was undertaken by the leave-one-out method and by removing studies with moderate/high risk of bias. The Mantel-Haenszel or inverse variance method was used to estimate risk factors of frailty.

RESULTS

A total of 14 studies met the inclusion criteria, involving 185,249 participants. The pooled prevalence in older adults with hypertension was 23% (95% CI 0.09-0.36) for frailty and 46% (95% CI 0.38-0.54) for prefrailty. The pooled prevalence of frailty was greater in studies with a higher proportion of females (24%, 95% CI 0.05-0.50), using multidimensional tools to define frailty (30%, 95% CI 0.10-0.51) and conducted in Western Pacific (27%, 95% CI 0.17-0.39). Age, female sex, depression, and previous hospitalizations were risk factors of frailty among older adults with hypertension.

CONCLUSION

Frailty and prefrailty are prevalent in community-dwelling older adults with hypertension, and limited risk factors are identified. This implicates the importance of frailty assessment integrated into the routine primary care for older adults with hypertension in community settings as well as the understanding of potential factors.

Mono- and biallelic variant effects on disease at biobank scale

Identifying causal factors for Mendelian and common diseases is an ongoing challenge in medical genetics¹. Population bottleneck events, such as those that occurred in the history of the Finnish population, enrich some homozygous variants to higher frequencies, which facilitates the identification of variants that cause diseases with recessive inheritance^2,3. Here we examine the homozygous and heterozygous effects of 44,370 coding variants on 2,444 disease phenotypes using data from the nationwide electronic health records of 176,899 Finnish individuals. We find associations for homozygous genotypes across a broad spectrum of phenotypes, including known associations with retinal dystrophy and novel associations with adult-onset cataract and female infertility. Of the recessive disease associations that we identify, 13 out of 20 would have been missed by the additive model that is typically used in genome-wide association studies. We use these results to find many known Mendelian variants whose inheritance cannot be adequately described by a conventional definition of dominant or recessive. In particular, we find variants that are known to cause diseases with recessive inheritance with significant heterozygous phenotypic effects. Similarly, we find presumed benign variants with disease effects. Our results show how biobanks, particularly in founder populations, can broaden our understanding of complex dosage effects of Mendelian variants on disease.

IL-1β expression driven by androgen receptor absence or inactivation promotes prostate cancer bone metastasis

We report the inverse association between the expression of androgen receptor (AR) and interleukin-1beta (IL-1β) in a cohort of patients with metastatic castration resistant prostate cancer (mCRPC). We also discovered that AR represses the IL-1β gene by binding an androgen response element (ARE) half-site located within the promoter, which explains the IL-1β expression in AR-negative (AR_NEG) cancer cells. Consistently, androgen-depletion or AR-pathway inhibitors (ARIs) de-repressed IL-1β in AR_POS cancer cells, both in vitro and in vivo. The AR transcriptional repression is sustained by histone de-acetylation at the H3K27 mark in the IL-1β promoter. Notably, patients' data suggest that DNA methylation prevents IL-1β expression, even if the AR-signaling axis is inactive. Our previous studies show that secreted IL-1β supports metastatic progression in mice by altering the transcriptome of tumor-associated bone stroma. Thus, in prostate cancer patients harboring AR_NEG tumor cells or treated with ADT/ARIs, and with the IL-1β gene unmethylated, IL-1β could condition the metastatic microenvironment to sustain disease progression.

Application of machine learning to identify top determinants of fibrofatty plaque burden by CCTA in humans with psoriasis

Introduction

Fibrofatty plaque burden (FFB) is a high-risk, vulnerable plaque feature comprised of an atheromatous core and fibrous cap with increased risk of coronary artery disease (CAD) [1]. Psoriasis (PSO) is a chronic inflammatory disease linked with atherosclerotic risk and premature cardiovascular disease, driven in part by vulnerable plaque rupture [2,3]. Machine learning (ML) previously showed the prognostic value of FFB in predicting 5-year risk of cardiac-related mortality in patients with CAD [4]. Whether ML can predict FFB in psoriasis is understudied.

Purpose

To use ML to identify top determinants of FFB by CCTA in PSO.

Methods

320 consecutive participants with psoriasis were recruited as part of an ongoing cohort study, of whom 307 had FFB analyzed with coronary computed tomography angiography (CCTA) and quantified by QAngio CT (Medis, The Netherlands). 140 out of 182 potential determinants were subjected to ML algorithms analyzed by random forest and validated by 5-fold cross validation to select the top determinants based on R-square criteria. Lipid concentration and size were measured by nuclear magnetic resonance (NMR) and sdLDL-C was calculated by Sampson's formula.

Results

The top 21 determinants of FFB at baseline were grouped into 3 categories: cardiometabolic risk factors (BMI, sex, DBP, mean arterial pressure, exercise, heart rate, glucose, anxiety, psoriasis disease duration), clinical measurements (basophils, platelets, hemoglobin, RBC, alkaline phosphatase, ALT, creatinine, neutrophil-to-lymphocyte ratio), and lipoproteins (LDL particle size, apolipoprotein A1, apolipoprotein B-to-A1 ratio, calculated sdLDL-C).

Conclusion

ML confirmed that FFB strongly correlates with cardiometabolic risk factors, clinical measurements, and lipoproteins. Further investigations into these top determinants of FFB over time may provide insight into potential therapeutic interventions that decrease cardiovascular risk in patients with chronic inflammatory diseases and should be validated in larger studies.

Funding Acknowledgement

Type of funding sources: Public Institution(s). Main funding source(s): This study was supported by the National Heart, Lung and Blood Institute (NHLBI) IntramuralResearch Program (ZIA-HL-06193). This research was made possible through the NIH MedicalResearch Scholars Program, a public-private partnership supported jointly by the NIH andcontributions to the Foundation for the NIH from the Doris Duke Charitable Foundation,Genentech, the American Association for Dental Research, the Colgate-Palmolive Company, andother private donors.

Effect of a home-based resistance exercise program in elderly participants with osteoporosis: a randomized controlled trial

The effectiveness of home-based resistance exercise in elder participants with osteoporosis remains unclear. This study demonstrates the beneficial effects of this mode of exercise on improving physical function, increasing confidence in exercise, and reducing fear of falling.

INTRODUCTION

This study aims to evaluate the effect of a home-based resistance exercise (HBRE) program versus control on physical function, exercise self-efficacy, falling efficacy, and health-related quality of life (HRQOL).

METHODS

This randomized controlled trial included 72 elderly participants with osteoporosis. Participants in the intervention group received a 12-week HBRE program, and the control group received usual care. The primary outcome was physical function, including muscle strength and balance ability; secondary outcomes were exercise self-efficacy, falling efficacy, and HRQOL. Within-group and between-group changes in outcome were evaluated by t-test and rank-sum test.

RESULTS

A total of 68 subjects were included in the final analysis. Improvement in physical function was significantly greater in the HBRE group compared with controls. On a psychological level, exercise self-efficacy and falling efficacy improved significantly in the HBRE group; no significant change was observed in the control group. Most of the dimensions of HRQOL demonstrated improvements as well. The adherence was 85.29%, with no adverse events related to the exercise.

CONCLUSION

A 12-week HBRE program was safe non-pharmacological therapy for elderly participants with osteoporosis, improving physical function, exercise self-efficacy, reduced fear of falling, and improved HRQOL.

TRIAL REGISTRATION

Chinese Clinical Trial Register: ChiCTR2100051455. Registered 23.09.21. Retrospectively registered.

Analysis of germline-driven ancestry-associated gene expression in cancers

Differential mRNA expression between ancestry groups can be explained by both genetic and environmental factors. We outline a computational workflow to determine the extent to which germline genetic variation explains cancer-specific molecular differences across ancestry groups. Using multi-omics datasets from The Cancer Genome Atlas (TCGA), we enumerate ancestry-informative markers colocalized with cancer-type-specific expression quantitative trait loci (e-QTLs) at ancestry-associated genes. This approach is generalizable to other settings with paired germline genotyping and mRNA expression data for a multi-ethnic cohort.

For complete details on the use and execution of this protocol, please refer to Carrot-Zhang et al. (2020), Robertson et al. (2021), and Sayaman et al. (2021).

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Protocol for obtaining controlled access TCGA datasets

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Protocols for quality control analysis and genotype imputation of TCGA germline data

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Statistical analysis for determining ancestry-associated SNPs

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Determination of ancestry-associated germline genetic variation driving mRNA expression

Publisher’s note: Undertaking any experimental protocol requires adherence to local institutional guidelines for laboratory safety and ethics.

DNA methylation dynamics and dysregulation delineated by high-throughput profiling in the mouse

We have developed a mouse DNA methylation array that contains 296,070 probes representing the diversity of mouse DNA methylation biology. We present a mouse methylation atlas as a rich reference resource of 1,239 DNA samples encompassing distinct tissues, strains, ages, sexes, and pathologies. We describe applications for comparative epigenomics, genomic imprinting, epigenetic inhibitors, patient-derived xenograft assessment, backcross tracing, and epigenetic clocks. We dissect DNA methylation processes associated with differentiation, aging, and tumorigenesis. Notably, we find that tissue-specific methylation signatures localize to binding sites for transcription factors controlling the corresponding tissue development. Age-associated hypermethylation is enriched at regions of Polycomb repression, while hypomethylation is enhanced at regions bound by cohesin complex members. Apc ^Min/+ polyp-associated hypermethylation affects enhancers regulating intestinal differentiation, while hypomethylation targets AP-1 binding sites. This Infinium Mouse Methylation BeadChip (version MM285) is widely accessible to the research community and will accelerate high-sample-throughput studies in this important model organism.

[Preconception reproductive health and birth outcome cohort in Chongqing: the cohort profile]

Birth cohort is an important platform to study the effect of early-life exposure on health outcome, but large cohorts to investigate the effect of preconception exposure, especially paternal exposure, on reproductive health and birth outcome are limited. The Preconception Reproductive Health and Birth Outcome Cohort (PREBIC) is a prospective birth cohort study which pays equal attention to the contribution of environmental, psychological, behavioral as well as other factors to reproductive health and adverse birth outcomes in both men and women in Chongqing, China. PREBIC started in 2019 and plans to recruit 20 800 reproductive-age couples with child-bearing willingness. Followed up was conducted to understand the conception status of the women within two years. Women in pregnancy would be visited at first, second, third trimesters and after delivery. The offspring would be monitored until 2 years old to understand the incidences of preterm birth, low birth weight, birth defects, neurodevelopmental disorders and other outcomes. Related information and biospecimen collections (including semen, peripheral blood, urine, placenta, umbilical cord, cord blood and oral swab) were scheduled in each period. By January 2022, PREBIC had recruited 8 698 participants from all 38 districts in Chongqing. The goal of PREBIC is to establish one of the largest prospective preconception birth cohorts covering both men and women, which might provide a unique insight to understand the effects of the full reproductive cycle on reproductive health and adverse outcomes, with especial emphasis on preconception exposures.

[Cone-beam CT analysis of external root resorption of maxillary incisors before and after traction of impacted canines]

Objective: To analyze the external root resorption of incisors caused by maxillary canine impaction, and to explore the changes of incisor external root resorption after orthodontic treatment. Methods: Twenty-four patients with impacted maxillary canines leading to external root resorption of incisors treated in Department of Orthodontics, Affiliated Hospital of Stomatology, Nanjing Medical University from July 2011 to January 2019 were selected. The age ranged from 10 to 14 years [(12.3±1.6) years], including 11 males and 14 females. The maxillary incisors with external root resorption before treatment were included in the resorption group (21 central incisors and 22 lateral incisors), and the maxillary incisors without external root resorption were used as the control group (26 central incisors and 21 lateral incisors). Cone-beam CT was taken before treatment, immediately after treatment and one year after treatment. At the one year follow-up 15 patients were collected (10 central incisors and 12 lateral incisors in the resorption group, while 16 central incisors and 12 lateral incisors in the control group). The root length and tooth volume of maxillary incisors were measured and analyzed before canine traction, after canine traction finished and at the one year follow-up. Results: After the treatment of maxillary impacted canines, the root length and volume of the central and lateral incisors in both resorption group and control group were significantly less than that before treatment (P<0.05). At the one year follow-up, the root length and volume of the incisors (central incisors in the resorption group and the central and lateral incisors in control group) were significantly less than those immediately after impacted canine traction (P<0.05). During the canine traction, the difference of the volume change in lateral incisors between the resorption group [(17±6) mm³] and the control group [(12±5) mm³] was statistically significant (t=2.51, P<0.05). During the one year follow-up period, the difference between the changes of the root length in maxillary central incisors in the resorption group [(0.5±0.4) mm] and in the control group [(0.2±0.1) mm] was statistically significant (t=2.35, P<0.05). Conclusions: For maxillary incisors with external root resorption caused by impacted maxillary canines, the external root resorption could not stop immediately after the treatment of impacted canines. The root resorption in maxillary lateral incisors mainly occured during the traction process, while the root resorption in maxillary central incisors existed during the orthodontic treatment and in the follow-up period.

Computational methods for single-cell DNA methylomes

Dissecting intercellular epigenetic differences is key to understanding tissue heterogeneity. Recent advances in single-cell DNA methylome profiling have presented opportunities to resolve this heterogeneity at the maximum resolution. While these advances enable us to explore frontiers of chromatin biology and better understand cell lineage relationships, they pose new challenges in data processing and interpretation. This review surveys the current state of computational tools developed for single-cell DNA methylome data analysis. We discuss critical components of single-cell DNA methylome data analysis, including data preprocessing, quality control, imputation, dimensionality reduction, cell clustering, supervised cell annotation, cell lineage reconstruction, gene activity scoring, and integration with transcriptome data. We also highlight unique aspects of single-cell DNA methylome data analysis and discuss how techniques common to other single-cell omics data analyses can be adapted to analyzing DNA methylomes. Finally, we discuss existing challenges and opportunities for future development.