Pathways linking workplace violence and suicidal ideation/non-suicidal self-injury among nurse staff: the mediating role of loneliness and depressive symptoms.

BACKGROUND: Nurses face disproportionately high rates of suicidal ideation and non-suicidal self-injury (NSSI). The role of workplace violence, loneliness, and depressive symptoms in exacerbating these issues is poorly understood. This study aims to explore these relationships to inform interventions for improving nurses' mental health. METHODS: A cross-sectional study involving 1,774 Chinese nurse staff selected through convenient sampling methods was conducted. Workplace violence, depressive symptoms, and loneliness were assessed using the Chinese versions of the Workplace Violence Scale (WVS), the 9-item Patient Health Questionnaire (PHQ-9), and a three-item loneliness scale, respectively. Participants completed self-report questionnaires anonymously to ensure adherence to ethical standards. Statistical analysis utilized structural equation modeling (SEM) to examine the intricate relationships among variables, thereby elucidating the impact of workplace violence, loneliness, and depressive symptoms on nurses' suicidal ideation/NSSI outcomes. RESULTS: Nurse staff 165 (7.8%) were reported different level of suicidal ideation and 139 (7.8%) participants were reported different level of NSSI. And the final model of workplace violence on suicidal ideation shown a good model fit index (CMIN/DF = 3.482 NFI = 0.969 CFI = 0.977 TLI = 0.955 RFI = 0.938, RMSEA = 0.037 SRMR = 0.035). The pathway of workplace violence to loneliness (ß = 0.163, P < 0.001), the indirect effect of workplace violence on suicidal ideation via loneliness and depressive symptoms were 0.100 (95%CI = 0.085, 0.121), the indirect effect of loneliness on suicidal ideation via depressive symptoms were 0.128 (95%CI = 0.100, 0.158). Similarly, the final model of workplace violence on NSSI shown a good model fit index (CMIN/DF = 3.482 NFI = 0.967 CFI = 0.976 TLI = 0.953 RFI = 0.935, RMSEA = 0.037 SRMR = 0.034), the pathways of workplace violence to NSSI (ß = 0.115, P < 0.001), the indirect effect of workplace violence on NSSI via loneliness and depressive symptoms were 0.075 (95%CI = 0.055, 0.096), the indirect effect of loneliness on NSSI via depressive symptoms were 0.102 (95%CI = 0.076, 0.130). CONCLUSION: Our study unveils the role of workplace violence in nurses' suicidal ideation and NSSI, mediated by loneliness and depressive symptoms. Interventions targeting workplace violence are crucial for nurses' well-being, potentially reducing loneliness and depressive symptoms and lowering the risk of suicidal ideation and NSSI. However, further research is needed to explore additional mediators and pathways, employing longitudinal designs to establish causality and develop tailored interventions for nurses affected by workplace violence.

Sensing antibody functions with a novel CCR8-responsive engineered cell.

Human chemokine receptor 8 (CCR8) is a promising drug target for immunotherapy of cancer and autoimmune diseases. Monoclonal antibody-based CCR8 targeted treatment shows significant inhibition in tumor growth. The inhibition of CCR8 results in the improvement of antitumor immunity and patient survival rates by regulating tumor-resident regulatory T cells. Recently monoclonal antibody drug development targeting CCR8 has become a research hotspot, which also promotes the advancement of antibody evaluation methods. Therefore, we constructed a novel engineered customized cell line HEK293-cAMP-biosensor-CCR8 combined with CCR8 and a cAMP-biosensor reporter. It can be used for the detection of anti-CCR8 antibody functions like specificity and biological activity, in addition to the detection of antibody-dependent cell-mediated cytotoxicity and antibody-dependent-cellular-phagocytosis. We obtained a new CCR8 mAb 22H9 and successfully verified its biological activities with HEK293-cAMP-biosensor-CCR8. Our reporter cell line has high sensitivity and specificity, and also offers a rapid kinetic detection platform for evaluating anti-CCR8 antibody functions.

Impact of workplace violence against psychological health among nurse staff from Yunnan-Myanmar Chinese border region: propensity score matching analysis.

BACKGROUND: Owing to different social background factor in Yunnan-Myanmar Chinese border region, stressful working environment may lead to extra psychological burden among nurse staff in China. However, the prevalence of workplace violence and its effect on psychological characteristics among nurse staff are still unclear. This study aims to explore the effect of workplace violence against psychological health among nurse staff from Yunnan-Myanmar Chinese border region. METHODS: A cross-sectional survey was conducted among 18 local governmental hospitals in Dehong districts. Participants were 1,774 nurses. Psychosocial characteristics were screened by sleep quality, the 9-item Patient Health Questionnaire for depressive symptoms, the generalized anxiety disorder-7 for anxiety symptoms, the Connor Davidson Resilience Scale - 10 item for resilience, the multidimensional scale of perceived social support for social support, the Chinese version of Work place Violence Scale for workplace violence. Propensity score matching and multivariate linear regression were applied to analyze the data. RESULTS: The nurse staff with workplace violence have a higher risk of bad sleep quality (b = -0.883, 95%CI = [-1.171, -0.595]), anxiety symptoms (b = 2.531, 95%CI = [2.031, 3.031]) and depressive symptoms (b = 3.227, 95%CI = [2.635, 3.819]), loneliness (b = 0.683, 95%CI = [0.503, 0.863]), perceived cognitive deficits (b = 1.629, 95%CI = [1.131, 2.127]), poor resilience (b = -2.012, 95%CI = [-2.963, -1.061]), and poor social support (b = -5.659, 95%CI = [-7.307, -4.011]). CONCLUSIONS: Preventing workplace violence can improve mental health outcomes significantly among nurse staff, including loneliness, perceived cognitive deficits, anxiety symptoms, depressive symptoms, sleep quality, resilience and social support.

Nanotechnology in diagnosis and therapy of gastrointestinal cancer.

Advances in nanotechnology have opened new frontiers in the diagnosis and treatment of cancer. Nanoparticle-based technology improves the precision of tumor diagnosis when combined with imaging, as well as the accuracy of drug target delivery, with fewer side effects. Optimized nanosystems have demonstrated advantages in many fields, including enhanced specificity of detection, reduced toxicity of drugs, enhanced effect of contrast agents, and advanced diagnosis and therapy of gastrointestinal (GI) cancers. In this review, we summarize the current nanotechnologies in diagnosis and treatment of GI cancers. The development of nanotechnology will lead to personalized approaches for early diagnosis and treatment of GI cancers.

Intracellular enzyme-powered DNA circuit with a tunable amplifier for miRNA imaging.

We describe an intracellular enzyme-powered DNA circuit probe with a tunable amplifier for sensitive and selective detection of miRNA. This approach has been successfully applied for in situ miRNA-21 fluorescence imaging in live cells. Also, we used chemicals to elevate the APE1 expression level rendering a tunable amplification strength for more flexible imaging applications.

Direct Kinetic Fingerprinting for High-Accuracy Single-Molecule Counting of Diverse Disease Biomarkers.

Methods for detecting and quantifying disease biomarkers in biofluids with high specificity and sensitivity play a pivotal role in enabling clinical diagnostics, including point-of-care tests. The most widely used molecular biomarkers include proteins, nucleic acids, hormones, metabolites, and other small molecules. While numerous methods have been developed for analyzing biomarkers, most techniques are challenging to implement for clinical use due to insufficient analytical performance, high cost, and/or other practical shortcomings. For instance, the detection of cell-free nucleic acid (cfNA) biomarkers by digital PCR and next-generation sequencing (NGS) requires time-consuming nucleic acid extraction steps, often introduces enzymatic amplification bias, and can be costly when high specificity is required. While several amplification-free methods for detecting cfNAs have been reported, these techniques generally suffer from low specificity and sensitivity. Meanwhile, the quantification of protein biomarkers is generally performed using immunoassays such as enzyme-linked immunosorbent assay (ELISA); the analytical performance of these methods is often limited by the availability of antibodies with high affinity and specificity as well as the significant nonspecific binding of antibodies to assay surfaces. To address the drawbacks of existing biomarker detection methods and establish a universal diagnostics platform capable of detecting different types of analytes, we have developed an amplification-free approach, named single-molecule recognition through equilibrium Poisson sampling (SiMREPS), for the detection of diverse biomarkers with arbitrarily high specificity and single-molecule sensitivity. SiMREPS utilizes the transient, reversible binding of fluorescent detection probes to immobilized target molecules to generate kinetic fingerprints that are detected by single-molecule fluorescence microscopy. The analysis of these kinetic fingerprints enables nearly perfect discrimination between specific binding to target molecules and any nonspecific binding. Early proof-of-concept studies demonstrated the in vitro detection of miRNAs with a limit of detection (LOD) of approximately 1 fM and >500-fold selectivity for single-nucleotide polymorphisms. The SiMREPS approach was subsequently expanded to the detection of rare mutant DNA alleles from biofluids at mutant allele fractions of as low as 1 in 1 million, corresponding to a specificity of >99.99999%. Recently, SiMREPS was generalized to protein quantification using dynamically binding antibody probes, permitting LODs in the low-femtomolar to attomolar range. Finally, SiMREPS has been demonstrated to be suitable for the in situ detection of miRNAs in cultured cells, the quantification of small-molecule toxins and drugs, and the monitoring of telomerase activity at the single-molecule level. In this Account, we discuss the principles of SiMREPS for the highly specific and sensitive detection of molecular analytes, including considerations for assay design. We discuss the generality of SiMREPS for the detection of very disparate analytes and provide an overview of data processing methods, including the expansion of the dynamic range using super-resolution analysis and the improvement of performance using deep learning algorithms. Finally, we describe current challenges, opportunities, and future directions for the SiMREPS approach.

Probing and regulating the activity of cellular enzymes by using DNA tetrahedron nanostructures.

Given the essential role of apurinic/apyrimidinic endonuclease (APE1) in gene repair and cancer progression, we report a novel approach for probing and regulating cellular APE1 activity by using DNA tetrahedrons. The tetrahedron with an AP site-containing antenna exhibits high sensitivity and specificity to APE1. It is suitable for APE1 in vitro detection (detection limit 5 pM) and cellular fluorescence imaging without any auxiliary transfection reagents, which discriminates the APE1 expression level of cancer cells and normal cells. In contrast, the tetrahedron with an AP site on its scaffold exhibits high binding affinity to APE1 but limits enzymatic catalysis making this nanostructure an APE1 inhibitor with an IC50 of 14.8 nM. It suppresses the APE1 activity in living cells and sensitizes cancer cells to anticancer drugs. We also demonstrate that the APE1 probe and inhibitor can be switched allosterically via stand displacement, which holds potential for reversible inhibition of APE1. Our approach provides a new way for fabricating enzyme probes and regulators and new insights into enzyme-substrate interactions, and it can be expanded to regulate other nucleic acid related enzymes.

Base excision repair-inspired DNA motor powered by intracellular apurinic/apyrimidinic endonuclease.

The transition of DNA nanomachines from test tubes to living cells would realize the ultimate goal of smart therapeutic dynamic DNA nanotechnology. The operation of DNA nanomachines in living cells remains challenging because it is difficult to utilize an endogenous driving force. Inspired by the base excision repair (BER) process, we demonstrate a 'burnt-bridge' DNA motor system powered by intracellular apurinic/apyrimidinic (AP) endonuclease APE1. The high specificity of APE1 to the AP site in double-stranded DNA permits directional and autonomous movement. The advanced single-molecule fluorescence technique was utilized to directly monitor the stepwise movement of the motor strand, confirming the excellent controllability and processivity of this system. The speed of this DNA motor relies highly on APE1 concentration, allowing discrimination by APE1 level against cancer cells and normal cells. Western blot was used to confirm APE1 expression level. Successful operation of the DNA motor in living cells demonstrates that an endogenous enzyme can operate the rationally designed DNA nanostructures in a programmable way, rather than digesting simple molecular probes. This is useful and practicable for broad application, such as for cellular diagnostic tools, gene regulators for DNA repair, and enzyme-mediated drug delivery.

Single-Molecule Kinetic Fingerprinting for the Ultrasensitive Detection of Small Molecules with Aptasensors.

Aptamers have emerged as promising molecular tools for small-molecule analyte sensing. However, the performance of such aptasensors is generally limited by leakage since it has been difficult to completely suppress signal in the absence of analyte, resulting in a compromise between sensitivity and specificity. Here, we describe a methodology for the ultrasensitive detection of analytes combining aptasensors with single-molecule kinetic fingerprinting. A short, fluorescently labeled DNA probe is utilized to detect the structural changes upon ligand binding to the designed hairpin-shaped aptasensor probe. The Poisson statistics of binding and dissociation events of the DNA probe to single surface-immobilized aptasensor molecules is monitored by total internal reflection fluorescence microscopy, permitting the high-accuracy discrimination of the ligand bound and ligand-free states, resulting in zero background. The programmable dynamics of the hairpin enables fine-tuning of the hybridization kinetics of the fluorescent probe, rendering the acquisition time sufficiently flexible to optimize discrimination. Remarkable detection limits are achieved for a diverse set of analytes when spiked into chicken meat extract: the nucleotide adenosine (0.3 pM), the insecticide acetamiprid (0.35 pM), and the dioxin-like toxin PCB-77 (0.72 pM), which is superior to recently reported aptasensors. Our generalizable method significantly improves the performance of aptasensors, with the potential to extend to other molecular biomarkers.

Digestion of Dynamic Substrate by Exonuclease Reveals High Single-Mismatch Selectivity.

The distinctive nuclease activity toward nucleic acid substrates enables various applications in analytical chemistry and dynamic DNA nanotechnology. λ Exonuclease is a widely used tool for the processing of PCR products, and DNA sequencing. This enzyme also shows promise for reducing the leakage (i.e., activation in absence of a correct input) in DNA-based analytical methods and nanotechnology due to its sensitivity to mismatches. However, the selectivity of λ exonuclease for single-mismatch in most applications is not high. Inspired by the increased specificity of dynamic probes in DNA nanotechnology, we enhanced the single-mismatch selectivity of λ exonuclease by using very short double-stranded DNA (dsDNA) as the substrate. From the bulk fluorescence measurements, short perfectly matched (PM) substrate which is as a correct input can be effectively digested, but the existence of single-mismatch drastically reduces the digestion rate. Real-time single-molecule kinetics analysis reveals that PM substrate can be selectively stabilized by the binding of λ exonuclease, which combines with the differential stability of transient hybridization of short substrates to yield high single-mismatch selectivity. An excellent selective assay for a single-nucleotide mutation in KRAS was demonstrated, which permits detecting this mutation from cell line at as low as 0.02%, holding potential for detecting rare mutations in circulating tumor DNA of early stage cancers.

Probing DNA Hybridization Equilibrium by Cationic Conjugated Polymer for Highly Selective Detection and Imaging of Single-Nucleotide Mutation.

Hybridization-based probes emerge as a promising tool for nucleic acid target detection and imaging. However, the single-nucleotide selectivity is still challenging because the specificity of hybridization reaction is typically low at room temperature. We disclose an effective and simple method for highly selective detection and in situ imaging of single-nucleotide mutation (SNM) by taking the advantages of the specific hybridization of short duplex and the signal amplifying effect of cationic conjugated polymer (CCP). Excellent discrimination of the nucleic acid strands only differing by single nucleotide was achieved enabling the sensitive detection of SNM at the abundance as low as 0.1%. Single-molecule fluorescence resonance energy transfer (smFRET) study reveals that the presence of CCP enhances the perfect matched duplex and the mismatched duplex to a different extent, which can be an explanation for the high single-nucleotide selectivity. Due to the simple design of the probe and the stable brightness of CCP, highly selective mRNA in situ imaging was achieved in fixed cells. Melanoma cell line A375 with BRAF V600E point mutation exhibits higher FRET efficiency than liver cancer cell line HegG2 that was not reported having the mutation at this point.

Discrimination Cascade Enabled Selective Detection of Single-Nucleotide Mutation.

Owing to the significance of single nucleotide mutation (SNM) for personalized medicine, the detection of SNM with high accuracy has recently attracted considerable interest. Here, we present a kinetic method for selective detection of SNM based on a discrimination cascade constructed by combining the toehold strand displacement (TSD) and endonuclease IV (Endo IV) catalyzed hydrolysis. The single-nucleotide specificity of the two DNA reactions allows highly selective detection of all types of single nucleotide changes (including single-nucleotide insertion and deletion), achieving a high discrimination factor with a median of 491 which is comparable with recently reported methods. For the first time, the enzyme assisted nucleic acid assay was characterized by single molecule analysis on total internal reflection fluorescence microscope (TIRFM) suggesting that the two steps do not work independently and the rate of TSD can be tuned by Endo IV facilitated conformation selection. The effective discrimination of the point mutation of BRAF gene in cancer and normal cell line suggests that this method can be a prominent post-PCR genotyping assay.

Single-Molecule Counting of Point Mutations by Transient DNA Binding.

High-confidence detection of point mutations is important for disease diagnosis and clinical practice. Hybridization probes are extensively used, but are hindered by their poor single-nucleotide selectivity. Shortening the length of DNA hybridization probes weakens the stability of the probe-target duplex, leading to transient binding between complementary sequences. The kinetics of probe-target binding events are highly dependent on the number of complementary base pairs. Here, we present a single-molecule assay for point mutation detection based on transient DNA binding and use of total internal reflection fluorescence microscopy. Statistical analysis of single-molecule kinetics enabled us to effectively discriminate between wild type DNA sequences and single-nucleotide variants at the single-molecule level. A higher single-nucleotide discrimination is achieved than in our previous work by optimizing the assay conditions, which is guided by statistical modeling of kinetics with a gamma distribution. The KRAS c.34 A mutation can be clearly differentiated from the wild type sequence (KRAS c.34 G) at a relative abundance as low as 0.01% mutant to WT. To demonstrate the feasibility of this method for analysis of clinically relevant biological samples, we used this technology to detect mutations in single-stranded DNA generated from asymmetric RT-PCR of mRNA from two cancer cell lines.

Metabolic Profile Changes of CCl4-Liver Fibrosis and Inhibitory Effects of Jiaqi Ganxian Granule.

Jiaqi Ganxian Granule (JGG) is a famous traditional Chinese medicine, which has been long used in clinical practice for treating liver fibrosis. However, the mechanism underlying its anti-hepatic fibrosis is still not clear. In this study, an Ultra-Performance Liquid Chromatography-Time-Of-Flight Mass Spectrometry (UPLC-TOF-MS)-based metabolomics strategy was used to profile the metabolic characteristic of serum obtained from a carbon tetrachloride (CCl4)-induced hepatic fibrosis model in Sprague-Dawley (SD) rats with JGG treatment. Through Principal Component Analysis (PCA) and Partial Least Square Discriminant Analysis (PLS-DA), it was shown that metabolic perturbations induced by CCl4 were inhibited after treatment of JGG, for 17 different metabolites related to CCl4. Among these compounds, the change tendency of eight potential drug targets was restored after the intervention with JGG. The current study indicates that JGG has a significant anti-fibrosis effect on CCl4-induced liver fibrosis in rats, which might be by regulating the dysfunction of sphingolipid metabolism, glycerophospholipid metabolism, N-acylethanolamine biosynthesis, fat digestion and absorption, while glycerophospholipid metabolism played vital roles in the inhibitory effects of JGG on hepatic fibrosis according to Metabolic Pathway Analysis (MetPA). Our findings indicated that the metabolomics approach may provide a useful tool for exploring potential biomarkers involved in hepatic fibrosis and elucidate the mechanisms underlying the action of therapies used in traditional Chinese medicine.

A two-layer assay for single-nucleotide variants utilizing strand displacement and selective digestion.

Point mutations have emerged as prominent biomarkers for disease diagnosis, particularly in the case of cancer. Discovering single-nucleotide variants (SNVs) is also of great importance for the identification of single-nucleotide polymorphisms within the population. The competing requirements of thermodynamic stability and specificity in conventional nucleic acid hybridization probes make it challenging to achieve highly precise detection of point mutants. Here, we present a fluorescence-based assay for low-abundance mutation detection based on toehold-mediated strand displacement and nuclease-mediated strand digestion that enables highly precise detection of point mutations. We demonstrate that this combined assay provides 50-1000-fold discrimination (mean value: 255) between all possible single-nucleotide mutations and their corresponding wild-type sequence for a model DNA target. Using experiments and kinetic modeling, we investigate probe properties that obtain additive benefits from both strand displacement and nucleolytic digestion, thus providing guidance for the design of enzyme-mediated nucleic acid assays in the future.