High-throughput single-cell mass spectrometry enables metabolic network analysis by resolving phospholipid C[double bond, length as m-dash]C isomers.

Single-cell mass spectrometry (MS) is an essential technology for sensitive and multiplexed analysis of metabolites and lipids for cell phenotyping and pathway studies. However, the structural elucidation of lipids from single cells remains a challenge, especially in the high-throughput scenario. Technically, there is a contradiction between the inadequate sample amount (i.e. a single cell, 0.5-20 pL) for replicate or multiple analysis, on the one hand, and the high metabolite coverage and multidimensional structure analysis that needs to be performed for each single cell, on the other hand. Here, we have developed a high-throughput single-cell MS platform that can perform both lipid profiling and lipid carbon-carbon double bond (C[double bond, length as m-dash]C) location isomer resolution analysis, aided by C[double bond, length as m-dash]C activation in unsaturated lipids by the Paternò-Büchi (PB) reaction and tandem MS, termed single-cell structural lipidomics analysis. The method can achieve a single-cell analysis throughput of 51 cells per minute. A total of 145 lipids were structurally characterized at the subclass level, of which the relative abundance of 17 isomeric lipids differing in the location of C[double bond, length as m-dash]C from 5 lipid precursors was determined. While cell-to-cell variations in MS1-based lipid profiling can be large, an advantage of quantifying lipid C[double bond, length as m-dash]C location isomers is the significantly improved quantitation accuracy. For example, the relative standard deviations (RSDs) of the relative amounts of PC 34:1 C[double bond, length as m-dash]C position isomers in MDA-MB-468 cells are half smaller than those measured for PC 34:1 as a whole by MS1 abundance profiling. Taken together, the developed method can be effectively used for in-depth structural lipid metabolism network analysis by high-throughput analysis of 142 MDA-MB-468 human breast cancer cells.

Facial emotion recognition function and white matter microstructural alterations in drug-naive, comorbidity-free autism.

Individuals with autism spectrum disorder have deficits in facial emotion recognition and white matter microstructural alterations. Nonetheless, most previous studies were confounded by different variables, such as psychiatric comorbidities and psychotropic medications used by ASD participants. Also, it remains unclear how exactly FER deficits are related to white matter microstructural alterations in ASD. Accordingly, we aimed to investigate the FER functions, white matter microstructure, and their relationship in drug-naive and comorbidity-free ASD individuals. 59 ASD individuals and 59 typically developed individuals were included, where 46 ASD and 50 TD individuals completed FER tasks. Covariance analysis showed scores were lower in both basic and complex FER tasks in the ASD group. Tract-Based Spatial Statistics showed FA values in widespread white matter fibers were lower in the ASD group than in the TD group, including forceps major and forceps minor of the corpus callosum, anterior thalamic radiation, corticospinal tract, cingulum, inferior frontal-occipital fasciculus, inferior longitudinal fasciculus, superior longitudinal fasciculus. Moreover, in the TD group but not the ASD group, the performance in the complex FER task was negatively correlated with the FA value in some white matter fibers, including forceps major of the corpus callosum, ATR, CT, cingulum, IFOF, ILF, SLF. Our study suggests children with ASD may experience deficits in facial emotion recognition and exhibit alterations in white matter microstructure. More importantly, our study indicates that white matter microstructural alterations may be involved in FER deficits in children with ASD.

Establishment and validation of a nomogram for subsequent first-cycle live births in patients diagnosed with recurrent implantation failure: a population-based analysis.

Background: The inability of patients with recurrent implantation failure (RIF) to achieve pregnancy and a live birth after multiple high-quality embryo transfer treatments has been recognized as a major obstacle to successful application of artificial reproductive technologies. The objective of this study was to establish and validate a nomogram for prediction of subsequent first-cycle live births to guide clinical practice in patients diagnosed with RIF. Methods: A total of 538 patients who underwent in vitro fertilization/intracytoplasmic sperm injection treatment and were first diagnosed with RIF at the Reproductive Center of the First Affiliated Hospital of Xinjiang Medical University between January 2017 and December 2020 were enrolled. The patients were randomly divided into a training cohort (n=408) and a validation set (n=175) in a ratio of 7:3. A nomogram model was constructed using the training set based on the results of univariate and multivariate logistic regression analyses and validated in the validation set. Results: Age, body mass index, duration of RIF, endometrial thickness, type of embryo transferred, and number of previous biochemical pregnancies were included in the nomogram for prediction of subsequent first-cycle live births in patients diagnosed with RIF. Analysis of the area under the receiver-operating characteristic curve, calibration plots, and decision curve analysis showed that our predictive model for live births had excellent performance. Conclusion: We have developed and validated a novel predictive model that estimates a woman's chances of having a live birth after a diagnosis of RIF and provides clinicians with a personalized clinical decision-making tool.

Quartet metabolite reference materials for inter-laboratory proficiency test and data integration of metabolomics profiling.

BACKGROUND: Various laboratory-developed metabolomic methods lead to big challenges in inter-laboratory comparability and effective integration of diverse datasets. RESULTS: As part of the Quartet Project, we establish a publicly available suite of four metabolite reference materials derived from B lymphoblastoid cell lines from a family of parents and monozygotic twin daughters. We generate comprehensive LC-MS-based metabolomic data from the Quartet reference materials using targeted and untargeted strategies in different laboratories. The Quartet multi-sample-based signal-to-noise ratio enables objective assessment of the reliability of intra-batch and cross-batch metabolomics profiling in detecting intrinsic biological differences among the four groups of samples. Significant variations in the reliability of the metabolomics profiling are identified across laboratories. Importantly, ratio-based metabolomics profiling, by scaling the absolute values of a study sample relative to those of a common reference sample, enables cross-laboratory quantitative data integration. Thus, we construct the ratio-based high-confidence reference datasets between two reference samples, providing "ground truth" for inter-laboratory accuracy assessment, which enables objective evaluation of quantitative metabolomics profiling using various instruments and protocols. CONCLUSIONS: Our study provides the community with rich resources and best practices for inter-laboratory proficiency tests and data integration, ensuring reliability of large-scale and longitudinal metabolomic studies.

Nanoparticle Deep-Subwavelength Dynamics Empowered by Optical Meron-Antimeron Topology.

Optical meron is a type of nonplanar topological texture mainly observed in surface plasmon polaritons and highly symmetric points of photonic crystals in the reciprocal space. Here, we report Poynting-vector merons formed at the real space of a photonic crystal for a Γ-point illumination. Optical merons can be utilized for subwavelength-resolution manipulation of nanoparticles, resembling a topological Hall effect on electrons via magnetic merons. In particular, staggered merons and antimerons impose strong radiation pressure on large gold nanoparticles (AuNPs), while focused hot spots in antimerons generate dominant optical gradient forces on small AuNPs. Synergistically, differently sized AuNPs in a still environment can be trapped or orbit in opposite directions, mimicking a coupled galaxy system. They can also be separated with a 10 nm precision when applying a flow velocity of >1 mm/s. Our study unravels a novel way to exploit topological textures for optical manipulation with deep-subwavelength precision and switchable topology in a lossless environment.

Development of cancer biomarker heat shock protein 90α certified reference material using two different isotope dilution mass spectrometry techniques.

Heat shock protein 90α (HSP90α) has been regarded as an important indicator for judging tumor metastasis and prognosis due to its significant upregulation in various tumors. Therefore, the accurate quantification of HSP90α is of great significance for clinical diagnosis and therapy of cancers. However, the lack of HSP90α certified reference material (CRM) leads to the accuracy and consistency of quantification methods not being effectively evaluated. Besides, quantitative results without traceability make comparisons between different studies difficult. In this study, an HSP90α solution CRM was developed from the recombinant protein raw material. The recombinant protein is a dimer, and the purity of the CRM candidate reached 96.71%. Both amino acid analysis-isotope dilution mass spectrometry (AAA-IDMS) and unique peptide analysis-isotope dilution mass spectrometry (UPA-IDMS) were performed to measure the content of HSP90α in the solution CRM candidate, and the certified value was assessed to be 66.2 ± 8.8 µg/g. Good homogeneity of the CRM was identified, and the stability examination suggested that the CRM was stable for at least 4 months at - 80 °C and for 7 days at 4 °C. With traceability to SI unit (kg), this CRM has potential to help establish a metrological traceability chain for quantification of HSP90α, which will make the quantification results standardized and comparable regardless of the quantitative methods.

Recent developments in ionization techniques for single-cell mass spectrometry.

The variation among individual cells plays a significant role in many biological functions. Single-cell analysis is advantageous for gaining insight into intricate biochemical mechanisms rarely accessible when studying tissues as a whole. However, measurement on a unicellular scale is still challenging due to unicellular complex composition, minute substance quantities, and considerable differences in compound concentrations. Mass spectrometry has recently gained extensive attention in unicellular analytical fields due to its exceptional sensitivity, throughput, and compound identification abilities. At present, single-cell mass spectrometry primarily concentrates on the enhancement of ionization methods. The principal ionization approaches encompass nanoelectrospray ionization (nano-ESI), laser desorption ionization (LDI), secondary ion mass spectrometry (SIMS), and inductively coupled plasma (ICP). This article summarizes the most recent advancements in ionization techniques and explores their potential directions within the field of single-cell mass spectrometry.

Precise Control of Trypsin Immobilization by a Programmable DNA Tetrahedron Designed for Ultrafast Proteome Digestion and Accurate Protein Quantification.

In proteomics research, with advantages including short digestion times and reusable applications, immobilized enzyme reactors (IMERs) have been paid increasing attention. However, traditional IMERs ignore the reasonable spatial arrangement of trypsin on the supporting matrixes, resulting in the partial overlapping of the active domain on trypsin and reducing digesting efficiency. In this work, a DNA tetrahedron (DNA TET)-based IMER Fe3O4-GO-AuNPs-DNA TET-Trypsin was designed and prepared. The distance between vertices of DNA TETs effectively controls the distribution of trypsin on the nanomaterials; thus, highly efficient protein digestion and accurate quantitative results can be achieved. Compared to the in-solution digestion (12-16 h), the sequence coverage of bovine serum albumin was up to 91% after a 2-min digestion by the new IMER. In addition, 3328 proteins and 18,488 peptides can be identified from HeLa cell protein extract after a 20-min digestion. For the first time, human growth hormone reference material was rapidly and accurately quantified after a 4-h digestion by IMER. Therefore, this new IMER has great application potential in proteomics research and SI traceable quantification.

Traceable value of immunoglobulin G against receptor-binding domain of SARS-CoV-2 confirmation and application to point-of-care testing system development.

A highly purified and bioactive immunoglobulin G monoclonal antibody against receptor-binding domain of SARS-CoV-2 (RBD-IgG-MAb) has been accurately quantified by amino acid determination using isotope dilution liquid chromatography-mass spectrometry. Absolute quantification of RBD-IgG-MAb was achieved by averaging 4 amino acid certified reference materials, which allows the quantitative value (66.1 ± 5.8 µg/L) to be traced to SI unit (mol). Afterwards, the RBD-IgG-MAb was employed as control and calibration compound for the development of a point-of-care testing (POCT) system based on colloidal gold lateral flow immunoassay, which aimed to rapidly and accurately detect the level of protective RBD-IgG after vaccination. Under the detection parameters, a sigmoidal curve has been plotted between signal intensity and the logarithmic concentration for quantitative detection with the limit of detection of about 0.39 µg/mL. The relative standard deviations of intra-assay and inter-assay were lower than 2.3% and 14%, and the recoveries ranged from 87 to 100%, respectively. Fingertip blood samples from 37 volunteers after vaccination were analyzed by the POCT system; results showed that levels of RBD-IgG in 33 out of 37 samples ranged from 0.45 to 2.46 µg/mL with the average level of 0.91 µg/mL. The developed POCT system has been successfully established with the quantity-traceability RBD-IgG-MAb as control and calibration compound, and the scientific contribution of this work can be promoted to other areas.

Autistic children's visual sensitivity to face movement.

There is a pressing need for studies of large sample sizes and variable age ranges to delineate the mechanism underlying reduced visual attention to biological motion in autism. Here we focused on the basic movement of the eyes or mouth in guiding attention. The stimuli face blinked continuously or moved the mouth silently. In a large sample (145 autistic and 132 non-autistic participants) ranging from 3 to 17 years old, we assessed whether autistic participants showed reduced visual attention to basic movement of the eyes or mouth using a free-viewing eye-tracking task. We found that, like non-autistic participants, autistic participants increased their eye-looking time when viewing the blinking face and increased mouth-looking time when viewing the mouth-moving face. Furthermore, these effects were stable across ages, suggesting the presence of a developmentally stable attentional capture by basic face movements in both groups. We also found that autistic participants looked less at basic face movement than non-autistic participants. Our results suggest that autistic children and adolescents could modulate their visual attention to the basic face movements, but their modulation effect is weaker than non-autistic participants. These results further our understanding of the mechanism underlying visual attention-to-face movement in autistic people.

Nanoliter atmospheric pressure photoionization-mass spectrometry for direct bioanalysis of polycyclic aromatic hydrocarbons.

Polycyclic aromatic hydrocarbons (PAHs) are a class of low-polarity environmental contaminants that have severe carcinogenic effects and have drawn worldwide attention. However, there remain challenges for current mass spectrometric ionization techniques in the analysis of low-polarity compounds in small-volume biosamples, such as single cells. In this work, we developed a nanoliter atmospheric pressure photoionization (nano-APPI) source and optimized its parameters for the detection of PAHs in small-volume samples. We evaluated the ionization performance of the source in direct and auxiliary gas-assisted photoionization modes and analyzed different PAH compounds as well as spiked biosamples. By combining the advantages of nano-electrospray ionization (nano-ESI) and atmospheric pressure photoionization (APPI), our newly developed nano-APPI source achieved high sensitivity for the analysis of PAHs down to the fmol level. Compared to conventional atmospheric pressure chemical ionization (APCI), the detection limit of PAHs was increased by 1-2 orders of magnitude. By optimizing various parameters, we achieved highly efficient ionization of PAHs, effective analysis of PAHs in mixed components, and sensitive detection of low-abundance PAHs in single-cell samples. Our optimized nano-APPI source was successfully applied for the sensitive analysis of PAHs in complex biological samples. Based on our study, we believe that nano-APPI holds great promise for toxicological studies on complex biological samples. The present work has implications for improving the detection sensitivity of low-polarity environmental contaminants and advancing the field of MS-based analysis of small-volume biosamples.

Quantification of 25OHD in serum by ID-LC-MS/MS based on oriented immobilization of antibody on magnetic materials.

Magnetic nanomaterials are widely used, but co-adsorption of impurities will lead to saturation. In this study, the aim was to prepare a magnetic nano-immunosorbent material based on orienting immobilization that can purify and separate 25-hydroxyvitamin D (25OHD) from serum and provides a new concept of sample pretreatment technology. Streptococcus protein G (SPG) was modified on the surface of the chitosan magnetic material, and the antibody was oriented immobilized using the ability of SPG to specifically bind to the Fc region of the monoclonal antibody. The antigen-binding domain was fully exposed and made up for the deficiency of the antibody random immobilization. Compared with the antibody in the random binding format, this oriented immobilization strategy can increase the effective activity of the antibody, and the amount of antibody consumed is saved to a quarter of the former. The new method is simple, rapid, and sensitive, without consuming a lot of organic reagents, and can enrich 25OHD after simple protein precipitation. Combining with liquid chromatography-tandem mass spectrometry (LC-MS/MS), the analysis can be completed in less than 30 min. For 25OHD2 and 25OHD3, the LOD was 0.021 and 0.017 ng mL-1, respectively, and the LOQ was 0.070 and 0.058 ng mL-1, respectively. The results indicated that the magnetic nanomaterials based on oriented immobilization can be applied as an effective, sensitive, and attractive adsorbent to the enrichment of serum 25OHD.

Investigation on acquired palbociclib resistance by LC-MS based multi-omics analysis.

Palbociclib is a specific CDK4/6 inhibitor that has been widely applied in multiple types of tumors. Different from cytotoxic drugs, the anticancer mechanism of palbociclib mainly depends on cell cycle inhibition. Therefore, the resistance mechanism is different. For clinical cancer patients, drug resistance is inevitable for almost all cancer therapies including palbociclib. We have trained palbociclib resistant cells in vitro to simulate the clinical situation and applied LC-MS multi-omics analysis methods including proteomic, metabolomic, and glycoproteomic techniques, to deeply understand the underly mechanism behind the resistance. As a result of proteomic analysis, the resistant cells were found to rely on altered metabolic pathways to keep proliferation. Metabolic processes related to carbohydrates, lipids, DNA, cellular proteins, glucose, and amino acids were observed to be upregulated. Most dramatically, the protein expressions of COX-1 and NDUFB8 have been detected to be significantly overexpressed by proteomic analysis. When a COX-1 inhibitor was hired to combine with palbociclib, a synergistic effect could be obtained, suggesting the altered COX-1 involved metabolic pathway is an important reason for the acquired palbociclib resistance. The KEGG pathway of N-glycan biosynthesis was identified through metabolomics analysis. N-glycoproteomic analysis was therefore included and the global glycosylation was found to be elevated in the palbociclib-resistant cells. Moreover, integration analysis of glycoproteomic data allowed us to detect a lot more proteins that have been glycosylated with low abundances, these proteins were considered to be overwhelmed by those highly abundant proteins during regular proteomic LC-MS detection. These low-abundant proteins are mainly involved in the cellular biology processes of cell migration, the regulation of chemotaxis, as well as the glycoprotein metabolic process which offered us great more details on the roles played by N-glycosylation in drug resistance. Our result also verified that N-glycosylation inhibitors could enhance the cell growth inhibition of palbociclib in resistant cells. The high efficiency of the integrated multi-omics analysis workflow in discovering drug resistance mechanisms paves a new way for drug development. With a clear understanding of the resistance mechanism, new drug targets and drug combinations could be designed to resensitize the resistant tumors.

Development and validation of a live birth prediction model for expected poor ovarian response patients during IVF/ICSI.

Background: A number of live birth predictive model during assisted reproductive technology treatment have been available in recent years, but few targeted evaluating the chances of live birth in poor ovarian response(POR) patients. The aim of this study was to develop a nomogram based on POSEIDON criteria to predict live birth in patients with expected POR. Methods: This retrospective cohort study using clinical data from 657 patients in POSEIDON Groups 3 and 4 (antral follicle count [AFC] ≤5 and AMH <1.2 ng/ml) in the Center for Reproductive Medicine, First Affiliated Hospital of Xinjiang Medical University, and Construction a nomogram model t. Results: Among 657 expected POR patients, 111 (16.89%) had live births, and 546 (83.11%) did not have live births. These were divided into a training set(n=438) and a validation set (n=219). Multivariate logistic regression analysis showed that the age (OR = 0.91, 95% CI: 0.86-0.97), BMI (OR = 1.98, 95% CI: 1.09-3.67), AMH (OR = 3.48, 95% CI: 1.45-8.51), normal fertilized oocytes (OR = 1.40, 95% CI: 1.21-1.63), and the basal FSH (OR = 0.89, 95% CI: 0.80-0.98) of the female were independent factors predicting live birth in patients with expected POR. Then, an individualized nomogram prediction model was built from these five factors. The area under the ROC curve of the live birth prediction model was 0.820 in the training set and 0.879 in the validation set. Conclusion: We have developed a nomogram combining clinical and laboratory factors to predict the probability of live birth in patients with an expected POR during IVF/ICSI, which can helpful for clinician in decision-making. However, the data comes from the same center, needs a prospective multicenter study for further in-depth evaluation and validation of this prediction model.

Docosahexaenoic acid improves cognition and hippocampal pyroptosis in rats with intrauterine growth restriction.

Background and Objective: Intrauterine growth restriction (IUGR) is defined as the failure of a fetus to reach its genetic growth potential in utero resulted by maternal, placental, fetal, and genetic factors. Previous studies have reported that IUGR is associated with a high incidence of neurological damage, although the precise causes of such damage remain unclear. We aimed to investigate whether cognitive impairment in rats with IUGR is related to pyroptosis of hippocampal neurons and determine the effect of early intervention with docosahexaenoic acid (DHA). Methods: Learning and memory function was assessed using the Morris water maze test. The morphological structure and ultrastructure of the hippocampus was examined via hematoxylin and eosin staining and electron microscopy respectively. The pyroptosis of hippocampal neuron was detected by gasdermin-D (GSDMD) immunofluorescence staining, mRNA and protein expression of nuclear localization leucine-rich-repeat protein 1 (NLRP1), caspase-1, GSDMD, and quantification of inflammatory cytokines interleukin (IL)-1ß and IL-18 in the hippocampus. Results: IUGR rats exhibited decreased learning and memory function, morphological structure and ultrastructural changes in hippocampus compared to controls. IUGR rats also exhibited increased hippocampal quantification of GSDMD immunofluorescence staining, increased mRNA and protein expression of NLRP1, caspase-1, and GSDMD, and increased quantification of IL-1ß and IL-18 in the hippocampus. Intervention with DHA attenuated these effects. Conclusion: Cognitive impairment in rats with IUGR may be related to pyroptosis of hippocampal neurons. Early intervention with DHA may attenuate cognitive impairment and reduce hippocampal pyroptosis in rats with IUGR.

Proteomics reveals that cell density could affect the efficacy of drug treatment.

In vitro cell biology study plays a fundamental role in biological and drug development research, but the repeatability and accuracy of cell studies remain to be low. Various uncertainties during the cell culture process could introduce bias into drug research. In this study, we evaluate the potential effects and underlying mechanisms induced by cell number differences in the cell seeding process. Normally, drug experiments are initiated 24 h after cell seeding, and the difference in the cell number at the time of inoculation leads to the difference in cell confluence (cell density) when drug research is conducted. While cell confluence is closely related to intercellular communication, surface protein interaction, cell autocrine as well as paracrine protein expression of cells, it might have a potential impact on the effect of biological studies such as drug treatment. This study used proteomics technology to comprehensively explore the different protein expression patterns between cells with different confluences. Due to the high sensitivity and high throughput of liquid chromatography-mass spectrometry (LC-MS/MS) detection, it was hired to evaluate the protein expression differences of Hep3B cells with 3 different confluences (30%, 50%, and 70%). The differential expressed proteins were analyzed by the Reactome pathway and the Gene Ontology (GO) pathway. Significant differences were identified across three confluences in terms of the number of proteins identified, the protein expression pattern, and the expression level of certain KEGG pathways. We found that those proteins involved in the cell cycle pathway were differently expressed: the higher the cell confluence, the higher these proteins expressed. A cell cycle inhibitor palbociclib was selected to further verify this observation. Palbociclib in the same dose was applied to cells with different confluence, the results indicated that the growth inhibition effect of palbociclib increases along with the increasing trend of cell cycle protein expression. The result indicated that cell density did influence the effect of drug treatment. Furthermore, three other drugs, cisplatin, paclitaxel, and imatinib, were used to treat the three liver cancer cell lines Hep3B, SUN387, and MHCC97, and a similar observation was obtained that drug effect would be different when the cell confluences were different. Therefore, selecting an appropriate number of cells for plating is vitally important at the beginning of a drug study.

[A 10-year retrospective study of pathogens and antimicrobial resistance in neonatal sepsis]. / æ–°ç”Ÿå„¿è´¥è¡€ç—‡ç— åŽŸèŒåŠè€è¯æ€§10年回顾性分析.

OBJECTIVES: To investigate the changes in the pathogen spectrum and antimicrobial resistance over time in neonatal sepsis. METHODS: The medical data were collected from the neonates who were diagnosed with sepsis in the Second Xiangya Hospital of Central South University from January 2010 to December 2019. The incidence rate of sepsis, the pathogen spectrum, and the characteristics of antimicrobial resistance were analyzed. RESULTS: The incidence rate of neonatal sepsis was 4.02% (447/11 111). The top four pathogens detected were coagulase-negative staphylococci (CoNS), Klebsiella pneumoniae, Escherichia coli, and Candida. The incidence rate of sepsis and the pathogen spectrum showed no significant changes over time. Klebsiella pneumoniae was the most frequent pathogen in preterm infants, very low birth weight infants, and small-for-gestational-age infants, accounting for 33.9%, 29.5%, and 42.5%, respectively. CoNS, Klebsiella pneumoniae, and Escherichia coli had a high resistance rate to penicillins and third-generation cephalosporins. CONCLUSIONS: The incidence of neonatal sepsis is high, and the main pathogen is CoNS. The pathogens of neonatal sepsis have a high resistance rate to penicillins and third-generation cephalosporins. It is recommended to enhance the prevention and control of neonatal infection, strengthen the surveillance of pathogens, and further standardize the rational use of antibiotics.

Etiology and clinical characteristics of neonatal sepsis in different medical setting models: A retrospective multi-center study.

Objective: General hospitals admit lower gestational age neonates than maternal and child health care centers, therefore associated with a higher morbidity and mortality. This study aimed to assess the etiology and clinical characteristics of neonatal sepsis in different medical setting models. Methods: Neonates admitted to 5 tertiary medical centers, including one national general hospital, two maternal and child health care hospitals and two regional general hospitals, in central-south China with culture-proven sepsis between January 2010 and December 2019 were included in the study. We compared maternal and neonatal characteristics, pathogen distribution, treatment and neonatal outcomes among 3 different medical setting models in this retrospective cohort. Results: We identified 757 episodes of culture-proven sepsis in 757 neonates. The predominant pathogens were coagulase-negative staphylococci, Klebsiella pneumoniae, Escherichia coli and Group B streptococci. A total of 683 neonates with detailed information were involved in further comparison; 54.6% were from the national general hospital, 35.9% were from the maternal and child health care hospital, and 9.5% were from the regional general hospital. Neonates in national and regional general hospitals had significantly lower gestational age and birthweight (P < 0.001). Patterns of pathogen distribution were different among these medical setting models. Early-onset sepsis was more common in maternal and child health care hospitals (61.4% vs. 42.1% vs. 46.7%, P < 0.001), while hospital-acquired late-onset sepsis was more common in national and regional general hospitals (32.7% vs. 33.3% vs. 11.4%, P < 0.001). The proportion of complications or comorbidities of neonates in maternal and child health care hospitals were significantly lower than neonates in national and regional general hospitals (P < 0.001). The case fatality rate was significantly higher in regional general hospitals (10.8% vs. 3.2% vs. 0.8%, P = 0.001). Conclusion: We report distinct patterns of clinical characteristics, pathogens and outcomes in patient subgroups with neonatal sepsis from national general hospital, maternal and child health care hospital and regional general hospital. It might have some implications for improvement of prevention, management and empirical antibiotic use in neonatal sepsis in different setting models, especially in resource-limited settings from middle and low-income countries.

Lateral Flow Immunoassay Based on Time-Resolved Fluorescence Microspheres for Rapid and Quantitative Screening CA199 in Human Serum.

Carbohydrate antigen 199 (CA199) is a serum biomarker which has certain value and significance in the diagnosis, prognosis, treatment, and postoperative monitoring of cancer. In this study, a lateral flow immunoassay based on europium (III) polystyrene time-resolved fluorescence microspheres (TRFM-based LFIA), integrated with a portable fluorescence reader, has been successfully establish for rapid and quantitative analysis of CA199 in human serum. Briefly, time-resolved fluorescence microspheres (TRFMs) were conjugated with antibody I (Ab1) against CA199 as detection probes, and antibody II (Ab2) was coated as capture element, and a "TRFMs-Ab1-CA199-Ab2" sandwich format would form when CA199 was detected by the TRFM-based LFIA. Under the optimal parameters, the detection limit of the TRFM-based LFIA for visible quantitation with the help of an ultraviolet light was 4.125 U/mL, which was four times lower than that of LFIA based on gold nanoparticles. Additionally, the fluorescence ratio is well linearly correlated with the CA199 concentration (0.00-66.0 U/mL) and logarithmic concentration (66.0-264.0 U/mL) for quantitative detection. Serum samples from 10 healthy people and 10 liver cancer patients were tested to confirm the performances of the point-of-care application of the TRFM-based LFIA, 20.0 U/mL of CA199 in human serum was defined as the threshold for distinguishing healthy people from liver cancer patients with an accuracy of about 60%. The establishment of TRFM-based LFIA will provide a sensitive, convenient, and efficient technical support for rapid screening of CA199 in cancer diagnosis and prognosis.

Diagnostic test of bioimpedance-based neural network algorithm in early cervical cancer.

Background: Colposcopy is a critical component of cervical cancer screening services, but the accuracy of colposcopy varies greatly due to the lack of standardized training for colposcopists and pathologists. Thus, to improve the accuracy of colposcopy in the detection of cervical lesions intelligently is urgent. Here, we explored the sensitivity and specificity of a bioimpedance-based neural network algorithm in distinguishing normal and precancerous cervical tissues. Methods: Bioimpedance data were collected using a bioimpedance analyzer (Mscan1.0B, Sealand Technology, Chengdu, China) from the cervices of 102 female patients with abnormal cervical cytology (≥atypical squamous cells of undetermined significance) who required further colposcopy. Finally, the data of 106 samples from 37 patients were included, among which 85were used as the training set and 21 as the validation set. Using the biopsy pathology at each locus as the gold standard, the sensitivity, specificity, predictive value, likelihood ratio, and false positive and false negative rates of the bioimpedance-based neural network in identifying the normal and precancerous cervical tissues were calculated. Results: The bioimpedance method had a sensitivity of 0.90 [95% confidence interval (CI): 0.54 to 0.99], specificity of 0.82 (95% CI: 0.48 to 0.97), positive predictive value of 0.82 (95% CI: 0.48 to 0.97), and a negative predictive value of 0.90 (95% CI: 0.54 to 0.99) in distinguishing normal and precancerous cervical tissues. The Kappa value was 0.72. Conclusions: The bioimpedance method was an intelligent method with relative good sensitivity and specificity in distinguishing benign cervical tissue and precancerous lesions and can therefore be used as an adjunctive test to colposcopy to improve the detection of cervical lesions.