Rapid, on-site quantitative determination of mycotoxins in grains using a multiple time-resolved fluorescent microsphere immunochromatographic test strip.

The label probe plays a crucial role in enhancing the sensitivity of lateral flow immunoassays. However, conventional fluorescent microspheres (FMs) have limitations due to their short fluorescence lifetime, susceptibility to background fluorescence interference, and inability to facilitate multi-component detection. In this study, carboxylate-modified Eu(III)-chelate-doped polystyrene nanobeads were employed as label probes to construct a multiple time-resolved fluorescent microsphere-based immunochromatographic test strip (TRFM-ICTS). This novel TRFM-ICTS facilitated rapid on-site quantitative detection of three mycotoxins in grains: Aflatoxin B1 (AFB1), Zearalenone (ZEN), and Deoxynivalenol (DON). The limit of detection (LOD) for AFB1, ZEN, and DON were found to be 0.03 ng/g, 0.11 ng/g, and 0.81 ng/g, respectively. Furthermore, the TRFM-ICTS demonstrated a wide detection range for AFB1 (0.05-8.1 ng/g), ZEN (0.125-25 ng/g), and DON (1.0-234 ng/g), while maintaining excellent selectivity. Notably, the test strip exhibited remarkable stability, retaining its detection capability even after storage at 4 °C for over one year. Importantly, the detection of these mycotoxins relied solely on simple manual operations, and with a portable reader, on-site detection could be accomplished within 20 min. This TRFM-ICTS presents a promising solution for sensitive on-site mycotoxin detection, suitable for practical application in various settings due to its sensitivity, accuracy, simplicity, and portability.

Xanthohumol, a prenylated chalcone, regulates lipid metabolism by modulating the LXRα/RXR-ANGPTL3-LPL axis in hepatic cell lines and high-fat diet-fed zebrafish models.

Angiopoietin-like 3 (ANGPTL3) acts as an inhibitor of lipoprotein lipase (LPL), impeding the breakdown of triglyceride-rich lipoproteins (TGRLs) in circulation. Targeting ANGPTL3 is considered a novel strategy for improving dyslipidemia and atherosclerotic cardiovascular diseases (ASCVD). Hops (Humulus lupulus L.) contain several bioactive prenylflavonoids, including xanthohumol (Xan), isoxanthohumol (Isoxan), 6-prenylnaringenin (6-PN), and 8-prenylnaringenin (8-PN), with the potential to manage lipid metabolism. The aim of this study was to investigate the lipid-lowering effects of Xan, the effective prenylated chalcone in attenuating ANGPTL3 transcriptional activity, both in vitro using hepatic cells and in vivo using zebrafish models, along with exploring the underlying mechanisms. Xan (10 and 20 µM) significantly reduced ANGPTL3 mRNA and protein expression in HepG2 and Huh7 cells, leading to a marked decrease in secreted ANGPTL3 proteins via hepatic cells. In animal studies, orally administered Xan significantly alleviated plasma triglyceride (TG) and cholesterol levels in zebrafish fed a high-fat diet. Furthermore, it reduced hepatic ANGPTL3 protein levels and increased LPL activity in zebrafish models, indicating its potential to modulate lipid profiles in circulation. Furthermore, molecular docking results predicted that Xan exhibits a higher binding affinity to interact with liver X receptor α (LXRα) and retinoic acid X receptor (RXR) than their respective agonists, T0901317 and 9-Cis-retinoic acid (9-Cis-RA). We observed that Xan suppressed hepatic ANGPTL3 expression by antagonizing the LXRα/RXR-mediated transcription. These findings suggest that Xan ameliorates dyslipidemia by modulating the LXRα/RXR-ANGPTL3-LPL axis. Xan represents a novel potential inhibitor of ANGPTL3 for the prevention or treatment of ASCVD.

Intergenerational transmission of parental child-rearing gender-role attitudes and its influence on gender roles in single-parent families.

BACKGROUND: The development of children's gender roles in single-parent families is worthy of attention. It may be affected by family members' gender roles and parental child-rearing gender-role attitudes (PCGA). PCGA will form a consistent or inconsistent intergenerational relationship between parents and children. OBJECTIVE: This study examined the intergenerational similarities in gender roles and PCGA. Also, the intergenerational transmission of parental child-rearing gender-role attitudes (ITPCGA) in single-parent families, and the impact of various family factors on children's gender roles were comprehensively considered. METHOD: Participants were 550 single-parent parent-adolescent dyads. The Gender-role Scale and the Parental Child-rearing Gender-role Attitude Scale were used to evaluate participants' gender-role and PCGA. Chi-square tests and logistic regression analyses were used to examine the intergenerational similarities in gender roles and PCGA, and the influencing family factors of ITPCGA and children's gender roles. RESULTS: The intergenerational similarities of gender role types and PCGA types existed. Both parents' gender roles and family gender pairs affected ITPCGA, father-daughter families and parents' undifferentiated and sex-typed gender roles significantly predicted undesirable ITPCGA. Family gender pair, parent's gender roles and ITPCGA types affected children's gender roles. Undesirable ITPCGA significantly predicted children's undifferentiated gender roles; father-daughter families and mother-son families, parents' undifferentiated and sex-typed gender roles significantly predicted children's sex-typed gender roles, and mother-son families and parents' reversed gender roles significantly predicted children's reversed gender role. CONCLUSIONS: This study highlights the effects of single-parent family gender pairs and parents' gender roles on ITPCGA, which influences the development of children's gender roles.

Body image in patients with prostate cancer undergoing treatment with hormone therapy: Observational study using both a cross-sectional and longitudinal design.

This study aims to examine changes in body image (BI) over time and factors related to BI among patients with prostate cancer who receive hormone therapy (HT). A cross-sectional design and longitudinal design were utilized. Patients with prostate cancer who received HT were recruited from the urology outpatient departments in two hospitals in Taiwan between August 2017 and December 2020. Cross-sectional data were collected from 177 patients who had started HT for prostate cancer. Longitudinal data were collected from 34 newly diagnosed patients before receiving HT and at 1, 3, 6, and 12 months after HT. The variables measured included hormonal symptoms and distress, self-efficacy, and BI. The results showed that BI dissatisfaction ranged from 6.1% to 17.2%. Hormonal symptoms and distress (e.g. lack of vitality) were correlated with BI dissatisfaction. Education on the side effects of HT and coping strategies can be provided to patients to prevent BI dissatisfaction.

The effect of childhood trauma on suicide risk: the chain mediating effects of resilience and mental distress.

BACKGROUND: Suicide is the fourth leading cause of death among young people aged 15-29 years. A large number of studies have found that mental disorder in adulthood is closely related to childhood trauma, and the relationship between childhood trauma and suicide risk is influenced by resilience and mental distress. This study aimed to explore the effects of childhood trauma on suicide risk among young people and the potential roles of resilience and mental distress in the relationship between childhood trauma on suicide risk. METHODS: A cross-sectional survey was conducted among 742 young adults who were in graduate school stage from multiple provinces and cities in China. The Childhood Trauma Questionnaire (CTQ-Short Form), Connor-Davison Resilience Scale (CD-RISC) and Suicide Behavior Questionnaire-Revised (SBQ-R) were used to measure young adults' childhood trauma, resilience and suicide risk, respectively. 9-items Patient Health Questionnaire (PHQ-9) and 7-items self-report Generalized Anxiety Disorder Scale (GAD-7) were used together to measure mental distress. Correlation analysis was performed to explore the initial relationships among the main variables. Structural equation modeling (SEM) was conducted to examine the chain mediating effects of resilience and mental distress in the relationship between childhood trauma and suicide risk. RESULTS: The structural equation modeling produced goodness of fit indices (χ2 /df = 3.668, p < 0.001, RMSEA = 0.060, NFI = 0.959, CFI = 0.969, GFI = 0.969, TLI = 0.955). Childhood trauma significantly predicted suicide risk (ß = 0.232, p < 0.001) and mental distress (ß = 0.181, p < 0.001), which had negative effect on resilience (ß = -0.233, p < 0.001). Resilience negatively affected mental distress (ß = -0.483, p < 0.001) and suicide risk (ß = -0.142, p = 0.001), while mental distress positively associated with suicide risk (ß = 0.219, p < 0.001). CONCLUSION: The current study revealed that resilience and mental distress played chain-mediating roles in the relationship between childhood trauma and suicide risk. This suggests that we should view the suicide risk of graduate students from a comprehensive perspective.

The Neuroprotective Effects of Flavonoid Fisetin against Corticosterone-Induced Cell Death through Modulation of ERK, p38, and PI3K/Akt/FOXO3a-Dependent Pathways in PC12 Cells.

The overactive hypothalamic-pituitary-adrenal (HPA) axis is believed to trigger the overproduction of corticosterone, leading to neurotoxicity in the brain. Fisetin is a flavonoid commonly found in fruits and vegetables. It has been suggested to possess various biological activities, including antioxidant, anti-inflammatory, and neuroprotective effects. This study aims to explore the potential neuroprotective properties of fisetin against corticosterone-induced cell death and its underlying molecular mechanism in PC12 cells. Our results indicate that fisetin, at concentrations ranging from 5 to 40 µM, significantly protected PC12 cells against corticosterone-induced cell death. Fisetin effectively reduced the corticosterone-mediated generation of reactive oxygen species (ROS) in PC12 cells. Fisetin treatments also showed potential in inhibiting the corticosterone-induced apoptosis of PC12 cells. Moreover, inhibitors targeting MAPK/ERK kinase 1/2 (MEK1/2), p38 MAPK, and phosphatidylinositol 3-kinase (PI3K) were found to significantly block the increase in cell viability induced by fisetin in corticosterone-treated cells. Consistently, fisetin enhanced the phosphorylation levels of ERK, p38, Akt, and c-AMP response element-binding protein (CREB) in PC12 cells. Additionally, it was found that the diminished levels of p-CREB and p-ERK by corticosterone can be restored by fisetin treatment. Furthermore, the investigation of crosstalk between ERK and CREB revealed that p-CREB activation by fisetin occurred through the ERK-independent pathway. Moreover, we demonstrated that fisetin effectively counteracted the corticosterone-induced nuclear accumulation of FOXO3a, an apoptosis-triggering transcription factor, and concurrently promoted FOXO3a phosphorylation and its subsequent cytoplasmic localization through the PI3K/Akt pathway. In conclusion, our findings indicate that fisetin exerts its neuroprotective effect against corticosterone-induced cell death by modulating ERK, p38, and the PI3K/Akt/FOXO3a-dependent pathways in PC12 cells. Fisetin emerges as a promising phytochemical for neuroprotection.

Pinostrobin modulates FOXO3 expression, nuclear localization, and exerts antileukemic effects in AML cells and zebrafish xenografts.

Acute myeloid leukemia (AML) is a disease characterized by abnormal cell proliferation in the bone marrow and is the most common quickly progressive leukemia in adults. Pinostrobin, a flavonoid phytochemical, has been reported to exhibit antioxidant, anti-inflammatory, and anticancer properties. In this study, we aimed to investigate the antileukemic effects of pinostrobin and its molecular mechanisms in human AML cells. Our study found that pinostrobin (0-80 µM) significantly reduced the viability of human AML cells, with the pronounced cytotoxic effects observed in MV4-11 > MOLM-13 > HL-60 > U-937 > THP-1 cells. Pinostrobin was found to suppress leukemia cell proliferation, modulate cell cycle progression, promote cell apoptosis, and induce monocytic differentiation in MV4-11 cells. In animal studies, pinostrobin significantly suppressed the growth of leukemia cells in a zebrafish xenograft model. Microarray-based transcriptome analysis showed that the differentially expressed genes (DEGs) in pinostrobin-treated cells were strongly associated with enriched Gene Ontology (GO) terms related to apoptotic process, cell death, cell differentiation, cell cycle progression, and cell division. Combining DisGeNET and STRING database analysis revealed that pinostrobin upregulates forkhead box 3 (FOXO3), a tumor suppressor in cancer development, and plays an essential role in controlling AML cell viability. Our study demonstrated that pinostrobin increases FOXO3 gene expression and promotes its nuclear translocation, leading to the inhibition of cell growth. Finally, the study found that pinostrobin, when combined with cytarabine, synergistically reduces the viability of AML cells. Our current findings shed light on pinostrobin's mechanisms in inhibiting leukemia cell growth, highlighting its potential as a chemotherapeutic agent or nutraceutical supplement for AML prevention or treatment.

The Citrus Flavonoid Nobiletin Downregulates Angiopoietin-like Protein 3 (ANGPTL3) Expression and Exhibits Lipid-Modulating Effects in Hepatic Cells and Adult Zebrafish Models.

Nobiletin, a dietary citrus flavonoid, exerts biological activities against hyperlipidemia, obesity, and atherosclerotic cardiovascular diseases (ASCVDs). The aim of this study was to explore the lipid-lowering effects of nobiletin and the underlying molecular mechanisms in vitro in hepatic cells and in vivo in zebrafish models. Transcriptome and gene ontology (GO) analyses of differentially expressed genes (DEGs) by gene set enrichment analysis (GSEA) showed that a set of twenty-eight core enrichment DEGs associated with "GO BP regulation of lipid metabolic process" (GO: 0019216) were significantly downregulated in nobiletin-treated cells. Among these genes, angiopoietin-like 3 (ANGPTL3), an inhibitor of lipoprotein lipase (LPL) activity that regulates TG-rich lipoprotein (TGRL) metabolism in circulation, was the protein most markedly downregulated by nobiletin. Nobiletin (20 and 40 µM) significantly reduced the levels of ANGPTL3 mRNA and intracellular and secreted ANGPTL3 proteins in hepatic cell lines. Furthermore, alleviation of secreted ANGPTL3 production by nobiletin was found to reinstate LPL catalytic activity. Nobiletin significantly inhibited ANGPTL3 promoter activity and attenuated the transcription factor liver X receptor-α (LXRα)-mediated ANGPTL3 transcription. Molecular docking analysis predicted that nobiletin could bind to the ligand-binding domain of LXRα, thereby counteracting LXRα activation. In animal studies, orally administered nobiletin significantly alleviated the levels of plasma triglycerides (TGs) and cholesterol in zebrafish fed a high-fat diet. Moreover, nobiletin significantly reduced the amounts of hepatic ANGPTL3 protein in zebrafish. Our findings suggest that nobiletin may regulate the LXRα-ANGPTL3-LPL axis and exhibit lipid-modulating effects in vitro and in vivo. Thus, nobiletin is a potential ANGPTL3 inhibitor for the regulation of lipid metabolism to ameliorate dyslipidemia and ASCVDs.

Correlation between gut microbiota and glucagon-like peptide-1 in patients with gestational diabetes mellitus.

BACKGROUND: Gestational diabetes mellitus (GDM) places both the mother and offspring at high risk of complications. Increasing evidence suggests that the gut microbiota plays a role in the pathogenesis of GDM. However, it is still unclear whether the gut microbiota is related to blood biochemical traits, particularly glucagon-like peptide-1 (GLP-1), in GDM patients. AIM: To explore the correlation between the gut microbiota and blood biochemical traits, particularly GLP-1, in GDM patients. METHODS: The V4 region of the 16S ribosomal ribonucleic acid (rRNA) gene was sequenced based on the fecal samples of 35 pregnant women with GDM and was compared to that of 25 pregnant women with normal glucose tolerance (NGT). RESULTS: The results showed that Ruminococcaceae_UCG-002, Ruminococcaceae_UCG-005, Clostri-dium_sensu_stricto_1, and Streptococcus were more abundant in the NGT group than in the GDM group. Bacteroides and Lachnoclostridium were more abundant in the GDM group than in the NGT group. Spearman's correlation analysis was performed to identify the relationships between microbiota genera and blood biochemical traits. Paraprevotella, Roseburia, Faecalibacterium, and Ruminococcaceae_UCG-002 were significantly negatively correlated with glucose. Ruminococcaceae_UCG-002 was significantly negatively correlated with hemoglobin A1c. Bacteroides was significantly positively correlated with glucose. Sutterella, Oscillibacter, and Bifidobacterium were significantly positively correlated with GLP-1. A random forest model showed that 20 specific genera plus glucose provided the best discriminatory power, as indicated by the area under the receiver operating characteristic curve (0.94). CONCLUSION: The results of this study reveal novel relationships between the gut microbiome, blood bio-chemical traits, particularly GLP-1, and GDM status. These findings suggest that some genera are crucial for controlling blood glucose-related indices and may be beneficial for GDM treatment. Alteration in the microbial composition of the gut may potentially serve as a marker for identifying individuals at risk of GDM.

Construction and evaluation of a prognostic risk model of tumor metastasis-related genes in patients with non-small cell lung cancer.

BACKGROUND: Lung cancer is a high-incidence cancer, and it is also the most common cause of cancer death worldwide. 80-85% of lung cancer cases can be classified as non-small cell lung cancer (NSCLC). METHODS: NSCLC transcriptome data and clinical information were downloaded from the TCGA database and GEO database. Firstly, we analyzed and identified the differentially expressed genes (DEGs) between non-metastasis group and metastasis group of NSCLC in the TCGA database, Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) were consulted to explore the functions of the DEGs. Thereafter, univariate Cox regression and LASSO Cox regression algorithms were applied to identify prognostic metastasis-related signature, followed by the construction of the risk score model and nomogram for predicting the survival of NSCLC patients. GSEA analyzed that differentially expressed gene-related signaling pathways in the high-risk group and the low-risk group. The survival of NSCLC patients was analyzed by the Kaplan-Meier method. ROC curve was plotted to evaluate the accuracy of the model. Finally, the GEO database was further applied to verify the metastasis­related prognostic signature. RESULTS: In total, 2058 DEGs were identified. GO functions and KEGG pathways analysis results showed that the DEGs mainly concentrated in epidermis development, skin development, and the pathway of Neuro active ligand -receptor interaction in cancer. A six-gene metastasis-related risk signature including C1QL2, FLNC, LUZP2, PRSS3, SPIC, and GRAMD1B was constructed to predict the overall survival of NSCLC patients. The reliability of the gene signature was verified in GSE13213. The NSCLC patients were grouped into low-risk and high-risk groups based on the median value of risk scores. And low-risk patients had lower risk scores and longer survival time. Univariate and multivariate Cox regression verified that this signature was an independent risk factor for NSCLC. CONCLUSION: Our study identified 6 metastasis biomarkers in the NSCLC. The biomarkers may contribute to individual risk estimation, survival prognosis.

A Maternally Inherited Rare Case with Chromoanagenesis-Related Complex Chromosomal Rearrangements and De Novo Microdeletions.

Chromoanagenesis is a phenomenon of highly complex rearrangements involving the massive genomic shattering and reconstitution of chromosomes that has had a great impact on cancer biology and congenital anomalies. Complex chromosomal rearrangements (CCRs) are structural alterations involving three or more chromosomal breakpoints between at least two chromosomes. Here, we present a 3-year-old boy exhibiting multiple congenital malformations and developmental delay. The cytogenetic analysis found a highly complex CCR inherited from the mother involving four chromosomes and five breakpoints due to forming four derivative chromosomes (2, 3, 6 and 11). FISH analysis identified an ultrarare derivative chromosome 11 containing three parts that connected the 11q telomere to partial 6q and 3q fragments. We postulate that this derivative chromosome 11 is associated with chromoanagenesis-like phenomena by which DNA repair can result in a cooccurrence of inter-chromosomal translocations. Additionally, chromosome microarray studies revealed that the child has one subtle maternal-inherited deletion at 6p12.1 and two de novo deletions at 6q14.1 and 6q16.1~6q16.3. Here, we present a familial CCR case with rare rearranged chromosomal structures and the use of multiple molecular techniques to delineate these genomic alterations. We suggest that chromoanagenesis may be a possible mechanism involved in the repair and reconstitution of these rearrangements with evidence for increasing genomic imbalances such as additional deletions in this case.

NF-κB inhibitor alpha has a cross-variant role during SARS-CoV-2 infection in ACE2-overexpressing human airway organoids.

As SARS-CoV-2 continues to spread worldwide, tractable primary airway cell models that accurately recapitulate the cell-intrinsic response to arising viral variants are needed. Here we describe an adult stem cell-derived human airway organoid model overexpressing the ACE2 receptor that supports robust viral replication while maintaining 3D architecture and cellular diversity of the airway epithelium. ACE2-OE organoids were infected with SARS-CoV-2 variants and subjected to single-cell RNA-sequencing. NF-κB inhibitor alpha was consistently upregulated in infected epithelial cells, and its mRNA expression positively correlated with infection levels. Confocal microscopy showed more IκBα expression in infected than bystander cells, but found concurrent nuclear translocation of NF-κB that IκBα usually prevents. Overexpressing a nondegradable IκBα mutant reduced NF-κB translocation and increased viral infection. These data demonstrate the functionality of ACE2-OE organoids in SARS-CoV-2 research and identify an incomplete NF-κB feedback loop as a rheostat of viral infection that may promote inflammation and severe disease.

5-Demethylnobiletin Inhibits Cell Proliferation, Downregulates ID1 Expression, Modulates the NF-κB/TNF-α Pathway and Exerts Antileukemic Effects in AML Cells.

Acute myeloid leukemia (AML) is characterized by the dysregulation of hematopoietic cell proliferation, resulting in the accumulation of immature myeloid cells in bone marrow. 5-Demethylnobiletin (5-demethyl NOB), a citrus 5-hydroxylated polymethoxyflavone, has been reported to exhibit various bioactivities, such as antioxidant, anti-inflammatory and anticancer properties. In this study, we investigated the antileukemic effects of 5-demethyl NOB and its underlying molecular mechanisms in human AML cells. We found that 5-demethyl NOB (20−80 µM) significantly reduced human leukemia cell viability, and the following trend of effectiveness was observed: THP-1 ≈ U-937 > HEL > HL-60 > K562 cells. 5-Demethyl NOB (20 and 40 µM) modulated the cell cycle through the regulation of p21, cyclin E1 and cyclin A1 expression and induced S phase arrest. 5-Demethyl NOB also promoted leukemia cell apoptosis and differentiation. Microarray-based transcriptome, Gene Ontology (GO) and Gene Set Enrichment Analysis (GSEA) of differentially expressed genes (DEGs) analysis showed that the expression of inhibitor of differentiation/DNA binding 1 (ID1), a gene associated with the GO biological process (BP) cell population proliferation (GO: 0008283), was most strongly suppressed by 5-demethyl NOB (40 µM) in THP-1 cells. We further demonstrated that 5-demethyl NOB-induced ID1 reduction was associated with the inhibition of leukemia cell growth. Moreover, DEGs involved in the hallmark gene set NF-κB/TNF-α signaling pathway were markedly enriched and downregulated by 5-demethyl NOB. Finally, we demonstrated that 5-demethyl NOB (20 and 40 µM), combined with cytarabine, synergistically reduced THP-1 and U-937 cell viability. Our current findings support that 5-demethyl NOB dramatically suppresses leukemia cell proliferation and may serve as a potential phytochemical for human AML chemotherapy.

Omicron mutations enhance infectivity and reduce antibody neutralization of SARS-CoV-2 virus-like particles.

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Omicron variant contains extensive sequence changes relative to the earlier-arising B.1, B.1.1, and Delta SARS-CoV-2 variants that have unknown effects on viral infectivity and response to existing vaccines. Using SARS-CoV-2 virus-like particles (VLPs), we examined mutations in all four structural proteins and found that Omicron and Delta showed 4.6-fold higher luciferase delivery overall relative to the ancestral B.1 lineage, a property conferred mostly by enhancements in the S and N proteins, while mutations in M and E were mostly detrimental to assembly. Thirty-eight antisera samples from individuals vaccinated with Pfizer/BioNTech, Moderna, or Johnson & Johnson vaccines and convalescent sera from unvaccinated COVID-19 survivors had 15-fold lower efficacy to prevent cell transduction by VLPs containing the Omicron mutations relative to the ancestral B.1 spike protein. A third dose of Pfizer vaccine elicited substantially higher neutralization titers against Omicron, resulting in detectable neutralizing antibodies in eight out of eight subjects compared to one out of eight preboosting. Furthermore, the monoclonal antibody therapeutics casirivimab and imdevimab had robust neutralization activity against B.1 and Delta VLPs but no detectable neutralization of Omicron VLPs, while newly authorized bebtelovimab maintained robust neutralization across variants. Our results suggest that Omicron has similar assembly efficiency and cell entry compared to Delta and that its rapid spread is due mostly to reduced neutralization in sera from previously vaccinated subjects. In addition, most currently available monoclonal antibodies will not be useful in treating Omicron-infected patients with the exception of bebtelovimab.

Carboxylated fluorescent microsphere based immunochromatographic test strip enabled sensitive and quantitative on-site detection for florfenicol in eggs.

Florfenicol (FF), used popularly in prevention and treatment of virus infections in livestock and poultry, has widely been found in eggs and harmful to human health. In this work, a sensitive and quantitative on-site detecting solution, monoclonal antibody-based carboxylated fluorescent microsphere immunochromatographic test strip assay (FM-ICTS), is design and applied for FF detection. The proposed method can sensitively detect FF in low detection limit of 0.030 ng/g and quantitatively measure its concentration from 0.1 ng/mL to 8.1 ng/mL (R2 = 0.9991) with high repeatability (CV<8.0 %). In addition, the established FM-ICTS method exhibited high measurement accuracy in FF samples as compared with HPLC-MS analysis and demonstrated satisfied recoveries (99.1-101.3 %). More importantly, the quantitative FF test strip demonstrate ultra-high stability, which presents approximately equivalent detection ability to the fresh one after stored at 4 °C for more than one year or stored at 37 °C for 60 days. Therefore, the proposed method is a promising solution for rapidly and sensitively quantitative determination of FF in eggs.

Neutralizing antibody activity against SARS-CoV-2 variants in gestational age-matched mother-infant dyads after infection or vaccination.

Pregnancy confers unique immune responses to infection and vaccination across gestation. To date, there are limited data comparing vaccine- and infection-induced neutralizing Abs (nAbs) against COVID-19 variants in mothers during pregnancy. We analyzed paired maternal and cord plasma samples from 60 pregnant individuals. Thirty women vaccinated with mRNA vaccines (from December 2020 through August 2021) were matched with 30 naturally infected women (from March 2020 through January 2021) by gestational age of exposure. Neutralization activity against the 5 SARS-CoV-2 spike sequences was measured by a SARS-CoV-2-pseudotyped spike virion assay. Effective nAbs against SARS-CoV-2 were present in maternal and cord plasma after both infection and vaccination. Compared with WT spike protein, these nAbs were less effective against the Delta and Mu spike variants. Vaccination during the third trimester induced higher cord-nAb levels at delivery than did infection during the third trimester. In contrast, vaccine-induced nAb levels were lower at the time of delivery compared with infection during the first trimester. The transfer ratio (cord nAb level divided by maternal nAb level) was greatest in mothers vaccinated in the second trimester. SARS-CoV-2 vaccination or infection in pregnancy elicits effective nAbs with differing neutralization kinetics that are influenced by gestational time of exposure.

Limited cross-variant immunity from SARS-CoV-2 Omicron without vaccination.

SARS-CoV-2 Delta and Omicron are globally relevant variants of concern. Although individuals infected with Delta are at risk of developing severe lung disease, infection with Omicron often causes milder symptoms, especially in vaccinated individuals1,2. The question arises of whether widespread Omicron infections could lead to future cross-variant protection, accelerating the end of the pandemic. Here we show that without vaccination, infection with Omicron induces a limited humoral immune response in mice and humans. Sera from mice overexpressing the human ACE2 receptor and infected with Omicron neutralize only Omicron, but not other variants of concern, whereas broader cross-variant neutralization was observed after WA1 and Delta infections. Unlike WA1 and Delta, Omicron replicates to low levels in the lungs and brains of infected animals, leading to mild disease with reduced expression of pro-inflammatory cytokines and diminished activation of lung-resident T cells. Sera from individuals who were unvaccinated and infected with Omicron show the same limited neutralization of only Omicron itself. By contrast, Omicron breakthrough infections induce overall higher neutralization titres against all variants of concern. Our results demonstrate that Omicron infection enhances pre-existing immunity elicited by vaccines but, on its own, may not confer broad protection against non-Omicron variants in unvaccinated individuals.

Neutralizing immunity in vaccine breakthrough infections from the SARS-CoV-2 Omicron and Delta variants.

Virus-like particle (VLP) and live virus assays were used to investigate neutralizing immunity against Delta and Omicron SARS-CoV-2 variants in 259 samples from 128 vaccinated individuals. Following Delta breakthrough infection, titers against WT rose 57-fold and 3.1-fold compared with uninfected boosted and unboosted individuals, respectively, versus only a 5.8-fold increase and 3.1-fold decrease for Omicron breakthrough infection. Among immunocompetent, unboosted patients, Delta breakthrough infections induced 10.8-fold higher titers against WT compared with Omicron (p = 0.037). Decreased antibody responses in Omicron breakthrough infections relative to Delta were potentially related to a higher proportion of asymptomatic or mild breakthrough infections (55.0% versus 28.6%, respectively), which exhibited 12.3-fold lower titers against WT compared with moderate to severe infections (p = 0.020). Following either Delta or Omicron breakthrough infection, limited variant-specific cross-neutralizing immunity was observed. These results suggest that Omicron breakthrough infections are less immunogenic than Delta, thus providing reduced protection against reinfection or infection from future variants.

Omicron mutations enhance infectivity and reduce antibody neutralization of SARS-CoV-2 virus-like particles.

The Omicron SARS-CoV-2 virus contains extensive sequence changes relative to the earlier arising B.1, B.1.1 and Delta SARS-CoV-2 variants that have unknown effects on viral infectivity and response to existing vaccines. Using SARS-CoV-2 virus-like particles (SC2-VLPs), we examined mutations in all four structural proteins and found that Omicron showed increased infectivity relative to B.1, B.1.1 and similar to Delta, a property conferred by S and N protein mutations. Thirty-eight antisera samples from individuals vaccinated with tozinameran (Pfizer/BioNTech), elasomeran (Moderna), Johnson & Johnson vaccines and convalescent sera from unvaccinated COVID-19 survivors had moderately to dramatically reduced efficacy to prevent cell transduction by VLPs containing the Omicron mutations. The Pfizer/BioNTech and Moderna vaccine antisera showed strong neutralizing activity against VLPs possessing the ancestral spike protein (B.1, B.1.1), with 3-fold reduced efficacy against Delta and 15-fold lower neutralization against Omicron VLPs. Johnson & Johnson antisera showed minimal neutralization of any of the VLPs tested. Furthermore, the monoclonal antibody therapeutics Casirivimab and Imdevimab had robust neutralization activity against B.1, B.1.1 or Delta VLPs but no detectable neutralization of Omicron VLPs. Our results suggest that Omicron is at least as efficient at assembly and cell entry as Delta, and the antibody response triggered by existing vaccines or previous infection, at least prior to boost, will have limited ability to neutralize Omicron. In addition, some currently available monoclonal antibodies will not be useful in treating Omicron-infected patients.

Limited Cross-Variant Immunity after Infection with the SARS-CoV-2 Omicron Variant Without Vaccination.

SARS-CoV-2 Delta and Omicron strains are the most globally relevant variants of concern (VOCs). While individuals infected with Delta are at risk to develop severe lung disease 1 , Omicron infection causes less severe disease, mostly upper respiratory symptoms 2,3 . The question arises whether rampant spread of Omicron could lead to mass immunization, accelerating the end of the pandemic. Here we show that infection with Delta, but not Omicron, induces broad immunity in mice. While sera from Omicron-infected mice only neutralize Omicron, sera from Delta-infected mice are broadly effective against Delta and other VOCs, including Omicron. This is not observed with the WA1 ancestral strain, although both WA1 and Delta elicited a highly pro-inflammatory cytokine response and replicated to similar titers in the respiratory tracts and lungs of infected mice as well as in human airway organoids. Pulmonary viral replication, pro-inflammatory cytokine expression, and overall disease progression are markedly reduced with Omicron infection. Analysis of human sera from Omicron and Delta breakthrough cases reveals effective cross-variant neutralization induced by both viruses in vaccinated individuals. Together, our results indicate that Omicron infection enhances preexisting immunity elicited by vaccines, but on its own may not induce broad, cross-neutralizing humoral immunity in unvaccinated individuals.