The first embryonic landscape of G-quadruplexes related to myogenesis.

BACKGROUND: DNA G-quadruplexes (G4s) represent a distinctive class of non-canonical DNA secondary structures. Despite their recognition as potential therapeutic targets in some cancers, the developmental role of G4 structures remains enigmatic. Mammalian embryonic myogenesis studies are hindered by limitations, prompting the use of chicken embryo-derived myoblasts as a model to explore G4 dynamics. This study aims to reveal the embryonic G4s landscape and elucidate the underlying mechanisms for candidate G4s that influence embryonic myogenesis. RESULTS: This investigation unveils a significant reduction in G4s abundance during myogenesis. G4s stabilizer pyridostatin impedes embryonic myogenesis, emphasizing the regulatory role of G4s in this process. G4 Cut&Tag sequencing and RNA-seq analyses identify potential G4s and DEGs influencing embryonic myogenesis. Integration of G4 and DEG candidates identifies 32 G4s located in promoter regions capable of modulating gene transcription. WGBS elucidates DNA methylation dynamics during embryonic myogenesis. Coordinating transcriptome data with DNA G4s and DNA methylation profiles constructs a G4-DMR-DEG network, revealing nine interaction pairs. Notably, the NFATC2 promoter region sequence is confirmed to form a G4 structure, reducing promoter mCpG content and upregulating NFATC2 transcriptional activity. CONCLUSIONS: This comprehensive study unravels the first embryonic genomic G4s landscape, highlighting the regulatory role of NFATC2 G4 in orchestrating transcriptional activity through promoter DNA methylation during myogenesis.

Pan-cancer analysis reveals CCL5/CSF2 as potential predictive biomarkers for immune checkpoint inhibitors.

BACKGROUND: Currently, there are no optimal biomarkers available for distinguishing patients who will respond to immune checkpoint inhibitors (ICIs) therapies. Consequently, the exploration of novel biomarkers that can predict responsiveness to ICIs is crucial in the field of immunotherapy. METHODS: We estimated the proportions of 22 immune cell components in 10 cancer types (6,128 tumors) using the CIBERSORT algorithm, and further classified patients based on their tumor immune cell proportions in a pan-cancer setting using k-means clustering. Differentially expressed immune genes between the patient subgroups were identified, and potential predictive biomarkers for ICIs were explored. Finally, the predictive value of the identified biomarkers was verified in patients with urothelial carcinoma (UC) and esophageal squamous cell carcinoma (ESCC) who received ICIs. RESULTS: Our study identified two subgroups of patients with distinct immune infiltrating phenotypes and differing clinical outcomes. The patient subgroup with improved outcomes displayed tumors enriched with genes related to immune response regulation and pathway activation. Furthermore, CCL5 and CSF2 were identified as immune-related hub-genes and were found to be prognostic in a pan-cancer setting. Importantly, UC and ESCC patients with high expression of CCL5 and low expression of CSF2 responded better to ICIs. CONCLUSION: We demonstrated CCL5 and CSF2 as potential novel biomarkers for predicting the response to ICIs in patients with UC and ESCC. The predictive value of these biomarkers in other cancer types warrants further evaluation in future studies.

Expression of a novel hydrolase MhpC in Brevibacillus parabrevis BCP-09 and its characteristics for degrading synthetic pyrethroids.

Synthetic pyrethroids are widely used insecticides which may cause chronic diseases in non-target organisms upon long-term exposure. Microbial degradation offers a reliable method to remove them from the environment. This study focused on Brevibacillus parabrevis BCP-09 and its enzymes for degrading pyrethroids. The predicted deltamethrin-degrading genes phnA and mhpC were used to construct recombinant plasmids. These plasmids, introduced into Escherichia coli BL21(DE3) cells and induced with L-arabinose. The results indicated that the intracellular crude enzyme efficiently degraded deltamethrin by 98.8 %, ß-cypermethrin by 94.84 %, and cyfluthrin by 73.52 % within 24 h. The hydrolytic enzyme MhpC possesses a catalytic triad Ser/His/Asp and a typical "Gly-X-Ser-X-Gly" conservative sequence of the esterase family. Co-cultivation of induced E. coli PhnA and E. coli MhpC resulted in degradation rates of 41.44 ± 3.55 % and 60.30 ± 4.55 %, respectively, for deltamethrin after 7 d. This study states that the degrading enzymes from B. parabrevis BCP-09 are an effective method for the degradation of pyrethroids, providing available enzyme resources for food safety and environmental protection.

Dual-channel discrimination of two lethal chemical warfare agents using an ESIPT-ICT-based fluorescent probe.

Among all kinds of chemical warfare agents, only cyanide and nerve agents can cause massive mortality at low concentrations. In this work, a dual-channel fluorescent probe CWAs-Thia capable of detecting cyanide and nerve agents is presented. The two reactive recognition units, pyridine and the thiazole-2-carbonyl group, of the probe for cyanide and nerve agents, respectively, produced red and blue fluorescent responses, respectively, which were attributed to excited-state intramolecular proton transfer and intramolecular charge transfer. CWAs-Thia is the first probe that can selectively recognize cyanide and nerve agent. And it has proven to be effective in visualizing cyanide and nerve agents in living cells.

Benzo(a)pyrene exposure during pregnancy leads to germ cell apoptosis in male mice offspring via affecting histone modifications and oxidative stress levels.

Infertility has gradually become a global health concern, and evidence suggests that exposure to environmental endocrine-disrupting chemicals (EDCs) represent one of the key causes of infertility. Benzo(a)pyrene (BaP) is a typical EDC that is widespread in the environment. Previous studies have detected BaP in human urine, semen, cervical mucus, oocytes and follicular fluid, resulting in reduced fertility and irreversible reproductive damage. However, the mechanisms underlying the effects of gestational BaP exposure on offspring fertility in male mice have not been fully explored. In this study, pregnant mice were administered BaP at doses of 0, 5, 10 and 20 mg/kg/day via gavage from Days 7.5 to 12.5 of gestation. The results revealed that BaP exposure during pregnancy disrupted the structural integrity of testicular tissue, causing a disorganized arrangement of spermatogenic cells, compromised sperm quality, elevated levels of histone modifications and increased apoptosis in the testicular tissue of F1 male mice. Furthermore, oxidative stress was also increased in the testicular tissue of F1 male mice. BaP activated the AhR/ERα signaling pathway, affected H3K4me3 expression and induced apoptosis in testicular tissue. AhR and Cyp1a1 were overexpressed, and the expression of key molecules in the antioxidant pathway, including Keap1 and Nrf2, was reduced. The combined effects of these molecules led to apoptosis in testicular tissues, damaging and compromising sperm quality. This impairment in testicular cells further contributed to compromised testicular tissues, ultimately impacting the reproductive health of F1 male mice.

Comparative and phylogenetic analyses of plastid genomes of the medicinally important genus Alisma (Alismataceae).

Alisma L. is a medicinally important genus of aquatic and wetland plants consisting of c. 10 recognized species. However, largely due to polyploidy and limited taxon and gene sampling, the phylogenomic relationships of Alisma remain challenging. In this study, we sequenced 34 accessions of Alismataceae, including eight of the ten species of Alisma, one species of Echinodorus and one species of Luronium, to perform comparative analyses of plastid genomes and phylogenetic analyses. Comparative analysis of plastid genomes revealed high sequence similarity among species within the genus. Our study analyzed structural changes and variations in the plastomes of Alisma, including IR expansion or contraction, and gene duplication or loss. Phylogenetic results suggest that Alisma is monophyletic, and constitutes four groups: (1) A. lanceolatum and A. canaliculatum; (2) the North American clade of A. subcordatum and A. triviale; (3) A. wahlenbergii and A. gramineum; and (4) A. plantago-aquatica from Eurasia and northern Africa with the eastern Asian A. orientale nested within it. Hence the results challenge the recognition of A. orientale as a distinct species and raise the possibility of treating it as a synonym of the widespread A. plantago-aquatica. The well-known Alismatis Rhizoma (Zexie) in Chinese medicine was likely derived from the morphologically variable Alisma plantago-aquatica throughout its long history of cultivation in Asia. The plastome phylogenetic results also support the tetraploid A. lanceolatum as the likely maternal parent of the hexaploid eastern Asian A. canaliculatum.

Integrated "Two-in-One" Strategy for High-Rate Electrocatalytic CO2 Reduction to Formate.

The electrochemical CO2 reduction reaction (ECR) is a promising pathway to producing valuable chemicals and fuels. Despite extensive studies reported, improving CO2 adsorption for local CO2 enrichment or water dissociation to generate sufficient H* is still not enough to achieve industrial-relevant current densities. Herein, we report a "two-in-one" catalyst, defective Bi nanosheets modified by CrOx (Bi-CrOx), to simultaneously promote CO2 adsorption and water dissociation, thereby enhancing the activity and selectivity of ECR to formate. The Bi-CrOx exhibits an excellent Faradic efficiency (≈ 100 %) in a wide potential range from ‒0.4 to ‒0.9 V. In addition, it achieves a remarkable formate partial current density of 687 mA cm‒2 at a moderate potential of ‒0.9 V without iR compensation, the highest value at ‒0.9 V reported so far. Control experiments and theoretical simulations revealed that the defective Bi facilitates CO2 adsorption/activation while the CrOx accounts for enhancing the protonation process via accelerating H2O dissociation. This work presents a pathway to boosting formate production through tuning CO2 and H2O species at the same time.

Risk factors for recurrent laryngeal nerve injury in microwave ablation of thyroid nodules: A multicenter study.

BACKGROUND AND PURPOSE: This study aimed to investigate the risk factors for recurrent laryngeal nerve (RLN) injury after microwave ablation (MWA) of thyroid nodules and to identify factors influencing the recovery time of post-procedure hoarseness. MATERIALS AND METHODS: We retrospectively analyzed data from patients who underwent MWA for thyroid nodules at five hospitals between November 2018 and July 2022. Patients were divided into malignant and benign nodule groups. Variables analyzed included nodule size and location, the shortest distance from nodules to the thyroid capsule and tracheoesophageal groove (TEG-D), and ablation parameters. Univariate and multivariate analyses were performed to identify risk factors. Kaplan-Meier and Cox analyses were used to evaluate the recovery time of hoarseness after MWA. RESULTS: The study included 1,216 patients (mean age 44 ± 12 [SD] years; 901 women) with 602 malignant nodules and 614 benign nodules. The posterior capsule distance (PCD) and TEG-D were identified as independent influencing factors for hoarseness in all patients (P = 0.014, OR = 0.068; P < 0.001, OR = 0.005; AUC = 0.869). TEG-D was a significant risk factor for hoarseness, with safe thresholds identified at 4.9 mm for malignant nodules and 2.2 mm for benign nodules. Among patients who developed hoarseness, those in the close-distance group (TEG-D≤2 mm) had a longer recovery time compared to the distant-distance group. TEG-D was an independent factor influencing recovery time (P = 0.008, HR = 11.204). CONCLUSION: Clinicians should consider several factors, particularly TEG-D and PCD, when assessing the risk of RLN injury before MWA. TEG-D was a vital independent factor influencing recovery time. SUMMARY: Clinicians should pay attention to several influencing factors for RLN injury before MWA and TEG-D was an independent influencing factor for recovery time of hoarseness after MWA.

Apolipoprotein E in patients with undiagnosed pleural effusion: a prospective diagnostic test accuracy study.

INTRODUCTION: Pleural effusion is common in clinical practice, and its differential diagnosis remains challenging for clinicians. This study investigates the diagnostic value of apolipoprotein E (apoE) in patients with undetermined pleural effusion. METHODS: This prospective, double-blind study enrolled 152 patients with undiagnosed pleural effusion. Their pleural fluid apoE levels were measured, and a receiver operating characteristics (ROC) curve was used to evaluate the diagnostic accuracy of apoE. Decision curve analysis (DCA) was used to assess apoE's net benefit. Subgroup analyses were performed to investigate the effect of age on the diagnostic accuracy of apoE. RESULTS: Among the included participants, 23 had heart failure (HF). HF patients had the lowest apoE level among pleural effusion patients. The area under the curve (AUC) of apoE for HF was 0.79 (95% CI: 0.69-0.89). At the threshold of 40 mg/L, the sensitivity and specificity of apoE were 0.96 (95% CI: 0.87-1.00) and 0.33 (95% CI: 0.25-0.42), respectively. The decision curve for apoE was above reference lines. The AUC of apoE decreased in older patients. CONCLUSION: Pleural fluid apoE has moderate diagnostic value for HF and has net benefits in patients with undiagnosed pleural effusion. The diagnostic accuracy of apoE decreases with age.

Association of choroidal thickness and blood flow features with asymmetric axial lengths in children with unilateral myopic anisometropia.

BACKGROUND: Considering that changes in the choroidal thickness are closely related to ocular growth, we studied the choroidal thickness (CT) and the blood flow features in children with unilateral myopic anisometropia (UMA) as well as investigating the relationship between choroidal changes and myopia. METHODS: Subjective refractive, axial length (AL), and biometric parameters were measured in 98 UMA children (age: 8-15 years). CT and choroidal blood-flow features, including the choroidal vessel volume (CVV), choroidal vascularity index (CVI), and choriocapillaris perfusion area (CCPA), were measured through swept-source optical coherence tomography angiography. The macular region was categorized into four concentric circles of diameters 0-1 mm (central fovea), 1-3 mm (parafovea), 3-6 mm (perifovea), and 6-9 mm (extended), and further categorized into superior (S), inferior (I), temporal (T), and nasal (N) quadrants. RESULTS: The aforementioned four regions of myopic eyes displayed significantly lower CT, CVV, and CVI than those of non-myopic eyes. CCPA changes differed across different regions of both the eyes (parts of N and T quadrants). There was an inverse association between CT and the interocular AL difference (central and other regions S, T quadrant). No correlation was noted between CVV and CVI with interocular AL difference. CT and CVV were positively correlated in the 0-6-mm macular region of myopic eyes (Spearman correlation coefficient = 0.763, P < 0.001). CONCLUSIONS: In UMA children, CCT and blood flow may be related to myopia progression. A robust correlation between CT and CVV in the 0-6-mm macular region and reduced CT and diminished blood flow indicated an association with myopia.

Antisense oligonucleotides enhance SLC20A2 expression and suppress brain calcification in a humanized mouse model.

Primary familial brain calcification (PFBC) is a genetic neurological disease, yet no effective treatment is currently available. Here, we identified five novel intronic variants in SLC20A2 gene from six PFBC families. Three of these variants increased aberrant SLC20A2 pre-mRNA splicing by altering the binding affinity of splicing machineries to newly characterized cryptic exons, ultimately causing premature termination of SLC20A2 translation. Inhibiting the cryptic-exon incorporation with splice-switching ASOs increased the expression levels of functional SLC20A2 in cells carrying SLC20A2 mutations. Moreover, by knocking in a humanized SLC20A2 intron 2 sequence carrying a PFBC-associated intronic variant, the SLC20A2-KI mice exhibited increased inorganic phosphate (Pi) levels in cerebrospinal fluid (CSF) and progressive brain calcification. Intracerebroventricular administration of ASOs to these SLC20A2-KI mice reduced CSF Pi levels and suppressed brain calcification. Together, our findings expand the genetic etiology of PFBC and demonstrate ASO-mediated splice modulation as a potential therapy for PFBC patients with SLC20A2 haploinsufficiency.

HTB50-2 Inhibits Growth and Migration of Triple-negative Breast Cancer via FOSL2/FOXC1 Signaling Axis and Subsequent Ferroptosis.

BACKGROUND: The manipulation of ferroptosis in cancer cells is a possible therapeutic technique that has been investigated for use in the treatment of cancer. Consequently, ferroptosis-inducing medications have recently received increased interest in cancer therapy. In this research, we assessed the anticancer efficacy of 14ß-hydroxy- 3ß-(ß-D-Glucopyranosyloxy)-5α-bufa-20,22-dienolide (HTB50-2), a natural product derived from the plant Helleborus thibetanus Franch, in Triple-Negative Breast Cancer (TNBC). Moreover, we also studied its potential mechanisms. METHODS: The biological effects of HTB50-2 in a series of breast cancer cell lines were analyzed using sulforhodamine B (SRB) and other methods. The migration ability was analyzed using three methods: wound healing assay, transwell assay, and Western blot. Meanwhile, the potential therapeutic value of HTB50-2 was evaluated in BALB/c mice by orthotopic transplantation. Transcriptome sequencing was conducted to explore the FOS-like antigen 2 (FOSL2) gene, and its role in ferroptosis was verified by Western blot and immunohistochemistry. The association of FOSL2 and ferroptosis-related genes was analyzed using NetworkAnalyst databases, and a TF-Gene interaction network was constructed. RESULTS: Ferroptosis was found to be induced in TNBC cells by HTB50-2. Furthermore, HTB50-2 inhibited tumor development by inducing ferroptosis in TNBC in vivo. Mechanistically, we demonstrated that a transcription factor FOSL2 mediated ferroptosis by HTB50-2. Additionally, it was found that Forkhead box C1 (FOXC1) was regulated by FOSL2 and correlated with ferroptosis. CONCLUSION: Our data suggest that HTB50-2 exerts its anti-cancer properties by ferroptosis via FOSL2/FOXC1 signaling pathway. Hence, HTB50-2 has an important application potential in the treatment of TNBC.

Vonoprazan-amoxicillin dual therapy for Helicobacter pylori eradication in Chinese population: A prospective, multicenter, randomized, two-stage study.

BACKGROUND: The efficacy of Vonoprazan-amoxicillin dual therapy (VAT) in the treatment of Helicobacter pylori (H. pylori) is controversial. AIM: To evaluate the efficacy of VAT in the Chinese population. METHODS: This prospective, multicenter, randomized, open-label, and two-stage study was conducted at 23 centers in Fujian, China (May 2021-April 2022). H. pylori-infected patients were randomized to bismuth quadruple therapy (BQT), BQT-Vonoprazan (BQT-V), seven-day VAT (VAT-7), ten-day VAT (VAT-10), and fourteen-day VAT (VAT-14) groups. The primary endpoint was the H. pylori eradication rate. The secondary endpoint was the frequency of adverse events. This study was registered with the Chinese Clinical Trial Registry, ChiCTR2100045778. RESULTS: In the first stage, VAT-7 and BQT-V groups were selected for early termination because less than 23 among 28 cases were eradicated. In the second stage, the eradication rates for BQT, VAT-10, and VA-14 were 80.2% [95% confidence interval (95%CI): 71.4%-86.8%], 93.2% (86.6%-96.7%), 92.2% (85.3%-96.0%) in the intention-to-treat (ITT) analysis, and 80.9% (95%CI: 71.7%-87.5%), 94.0% (87.5%-97.2%), and 93.9% (87.4%-97.2%) in the per-protocol analysis. The ITT analysis showed a higher eradication rate in the VAT-10 and VAT-14 groups than in the BQT group (P = 0.022 and P = 0.046, respectively). The incidence of adverse events in the VAT-10 and VAT-14 groups was lower than in the BQT group (25.27% and 13.73% vs 37.62%, respectively; P < 0.001). CONCLUSION: VAT with a duration of 10 or 14 days achieves a higher eradication rate than the BQT, with a more tolerable safety profile in H. pylori-infected patients in Fujian.

Tumor markers determination in malignant pleural effusion: pearls and pitfalls.

Serum and pleural fluid tumor markers are well-recognized auxiliary diagnostic tools for malignant pleural effusion (MPE). Here, we discuss some pearls and pitfalls regarding the role of tumor markers in MPE management. The following issues are discussed in this article: What is the appropriate clinical scenario for evaluating pleural tumor markers? Which tumor markers should be advocated for diagnosing MPE? Can extremely high levels of tumor markers be employed to establish a diagnosis of MPE? Does the serum-to-pleural fluid ratio of a tumor marker have the same diagnostic efficacy as the measurement of that marker alone in the pleural fluid? Can tumor markers be used to estimate the risk of specific cancers? What should be considered when interpreting the diagnostic accuracy of tumor markers? How should tumor marker studies be performed? We addressed these issues with published works, particularly systematic reviews and meta-analyses.

Synthesis and antiproliferative evaluation of new hybrids of piperine and acylhydrazone.

Piperine, a natural amide isolated from the genus of Piper, serves as a pharmacophore in medicinal chemistry. In this study, we synthesised and evaluated 18 novel piperine-acylhydrazone hybrids (4a-4r) for their antiproliferative activities in vitro. The structures of these hybrids were validated using 1H,13C NMR, and HR-ESI-MS data. Furthermore, we screened all synthesised compounds for their antiproliferative activities against three human cancer cell lines: FaDu (laryngeal carcinoma cells), HepG2 (hepatoblastoma carcinoma cells), and MGC803 (gastric carcinoma cells). Among them, compound 4o exhibited significantly inhibitory activities against FaDu, HepG2, and MGC803 with IC50 values of 13.85 ± 0.19, 11.02 ± 1.45, and 13.47 ± 3.43 µM, respectively, which was approximately two-fold lower than the positive control cisplatin. These findings suggest that compound 4o has the potential to be promising leads for the design of anti-cancer drugs.

Pleural pro-gastrin releasing peptide is a potential diagnostic marker for malignant pleural effusion induced by small-cell lung cancer.

Background: Serum pro-gastrin releasing peptide (proGRP) is a well-recognized diagnostic marker for small cell lung cancer (SCLC). Pleural effusion is common in patients with advanced SCLC. The diagnostic accuracy of pleural proGRP for malignant pleural effusion (MPE) has not yet been established. This study aimed to evaluate the diagnostic accuracy of pleural proGRP for MPE. Methods: We prospectively recruited patients with undiagnosed pleural effusions from two centers (Hohhot and Changshu). An electrochemiluminescence immunoassay was used to detect pleural fluid proGRP. The diagnostic accuracy of proGRP for MPE was evaluated using a receiver operating characteristic (ROC) curve. Results: In both the Hohhot (n=153) and Changshu (n=58) cohorts, pleural proGRP in MPE patients did not significantly differ from that in patients with benign pleural effusions (BPEs) (Hohhot, P=0.91; Changshu, P=0.12). In the Hohhot and Changshu cohorts, the areas under the curves (AUCs) of proGRP were 0.51 [95% confidence interval (CI): 0.41-0.60] and 0.62 (95% CI: 0.47-0.77), respectively. However, patients with SCLC-induced MPE had significantly higher proGRP levels than those with BPE and other types of MPE (P=0.001 for both). In the pooled cohort, the AUC of proGRP for SCLC-induced MPE was 0.90 (95% CI: 0.78-1.00, P=0.001). At a threshold of 40 pg/mL, proGRP had a sensitivity of 1.00 (95% CI: 0.61-1.00) and specificity of 0.59 (95% CI: 0.52-0.66). The positive likelihood ratio was 2.61 (95% CI: 1.99-3.41), and the negative likelihood ratio was 0. Conclusions: Pleural proGRP has no diagnostic value for MPE, but has high diagnostic accuracy for SCLC-induced MPE. In patients with proGRP levels <40 pg/mL, MPE secondary to SCLC can be excluded.

Exploring the diagnostic potential of immunoglobulin A-microbiota interplay in liver cirrhosis and spontaneous bacterial peritonitis.

The human gut microbiota significantly impacts health, including liver conditions like liver cirrhosis (LC) and spontaneous bacterial peritonitis (SBP). Immunoglobulin A (IgA) plays a central role in maintaining gut microbial balance. Understanding IgA's interplay with gut microbiota and liver health is crucial. This study explores the relationship between fecal IgA levels, gut microbiota, and liver injury severity. A total of 69 LC patients and 30 healthy controls were studied. Fecal IgA levels were measured using ELISA, and IgA-coated bacteria were quantified via flow cytometry. Microbiota diversity and composition were assessed through 16S rRNA sequencing. Liver injury severity was graded using the Child-Pugh score. Statistical analyses determined correlations. LC patients had higher fecal IgA levels than controls, correlating positively with liver injury severity. Microbiota diversity decreased with severity, accompanied by shifts in composition favoring pro-inflammatory species. Ralstonia abundance positively correlated with liver injury, whereas Faecalibacterium showed a negative correlation. Specific microbial markers for SBP were identified. Functional profiling revealed altered microbial functionalities in LC and SBP. Elevated fecal IgA levels, coupled with microbiota alterations, correlate with liver injury severity in LC patients. Modulating gut microbiota could be a promising strategy for managing liver-related conditions. Further research is needed to understand underlying mechanisms and translate findings into clinical practice, potentially improving patient outcomes.

Stillbirth risk by fetal size among 126.5 million births in 15 countries from 2000 to 2020: A fetuses-at-risk approach.

OBJECTIVE: To compare stillbirth rates and risks for small for gestational age (SGA), large for gestational age (LGA) and appropriate for gestational age (AGA) pregnancies at 24-44 completed weeks of gestation using a birth-based and fetuses-at-risk approachs. DESIGN: Population-based, multi-country study. SETTING: National data systems in 15 high- and middle-income countries. POPULATION: Live births and stillbirths. METHODS: A total of 151 country-years of data, including 126 543 070 births across 15 countries from 2000 to 2020, were compiled. Births were categorised into SGA, AGA and LGA using INTERGROWTH-21st standards. Gestation-specific stillbirth rates, with total births as the denominator, and gestation-specific stillbirth risks, with fetuses still in utero as the denominator, were calculated from 24 to 44 weeks of gestation. MAIN OUTCOME MEASURES: Gestation-specific stillbirth rates and risks according to size at birth. RESULTS: The overall stillbirth rate was 4.22 per 1000 total births (95% CI 4.22-4.23) across all gestations. Applying the birth-based approach, the stillbirth rates were highest at 24 weeks of gestation, with 621.6 per 1000 total births (95% CI 620.9-622.2) for SGA pregnancies, 298.4 per 1000 total births (95% CI 298.1-298.7) for AGA pregnancies and 338.5 per 1000 total births (95% CI 337.9-339.0) for LGA pregnancies. Applying the fetuses-at-risk approach, the gestation-specific stillbirth risk was highest for SGA pregnancies (1.3-1.4 per 1000 fetuses at risk) prior to 29 weeks of gestation. The risk remained stable between 30 and 34 weeks of gestation, and then increased gradually from 35 weeks of gestation to the highest rate of 8.4 per 1000 fetuses at risk (95% CI 8.3-8.4) at ≥42 weeks of gestation. The stillbirth risk ratio (RR) was consistently high for SGA compared with AGA pregnancies, with the highest RR observed at ≥42 weeks of gestation (RR 9.2, 95% CI 15.2-13.2), and with the lowest RR observed at 24 weeks of gestation (RR 3.1, 95% CI 1.9-4.3). The stillbirth RR was also consistently high for SGA compared with AGA pregnancies across all countries, with national variability ranging from RR 0.70 (95% CI 0.43-0.97) in Mexico to RR 8.6 (95% CI 8.1-9.1) in Uruguay. No increased risk for LGA pregnancies was observed. CONCLUSIONS: Small for gestational age (SGA) was strongly associated with stillbirth risk in this study based on high-quality data from high- and middle-income countries. The highest RRs were seen in preterm gestations, with two-thirds of the stillbirths born as preterm births. To advance our understanding of stillbirth, further analyses should be conducted using high-quality data sets from low-income settings, particularly those with relatively high rates of SGA.

Exploring the effects of environmentally relevant concentrations of tris(2-chloroethyl) phosphate on tadpole health: A comprehensive analysis of intestinal microbiota and hepatic transcriptome.

Tris(2-chloroethyl) phosphate (TCEP), a chlorinated organophosphate ester, is commonly found in aquatic environments. Due to its various toxic effects, it may pose a risk to the health of aquatic organisms. However, the potential impacts of TCEP exposure on the intestinal microbiota and hepatic function in amphibians have not been reported. This study investigated the impact of long-term exposure to environmentally relevant concentrations of TCEP (0, 3, and 90 µg/L) on the intestinal microbiota and hepatic transcriptome of Polypedates megacephalus tadpoles. The results showed that the body size of the tadpoles decreased significantly with an increase in TCEP concentration. Additionally, TCEP exposure affected the diversity and composition of the intestinal microbiota in tadpoles, leading to significant changes in the relative abundance of certain bacterial groups (the genera Aeromonas decreased and Citrobacter increased) and potentially promoting a more even distribution of microbial species, as indicated by a significant increase in the Simpson index. Moreover, the impact of TCEP on hepatic gene expression profiles in tadpoles was significant, with the majority of differentially expressed genes (DEGs) (709 out of 906 total DEGs in 3 µg/L of TCEP versus control, and 344 out of 387 DEGs in 90 µg/L of TCEP versus control) being significantly down-regulated, which were primarily related to immune response and immune system process. Notably, exposure to TCEP significantly reduced the relative abundance of the genera Aeromonas and Cetobacterium in the tadpole intestine. This reduction was positively correlated with the down-regulated expression of immune-related genes in the liver of corresponding tadpoles. In summary, these findings provide empirical evidence of the potential health risks to tadpoles exposed to TCEP at environmentally relevant concentrations.