Analytical and clinical performance evaluation of a new NT-proBNP assay.

BACKGROUND: The study evaluated the performance of the Mindray N-terminal pro-B-type natriuretic peptide (NT-proBNP) in a healthy population in China, focusing on creating a reference range for future clinical applications adjusted according to different demographics. METHODS: The study measured NT-proBNP in 2277 healthy individuals. We analyzed age and sex-stratified data, performed precision, accuracy, linearitcvy, and detection limit studies, and evaluated method comparison and consistency between Roche and Mindray assays on 724 serum samples. We used Excel 2010, Medcalc, and GraphPad Prism 9. RESULTS: In males, the 97.5th centile NT-proBNP concentration at age < 45, 45 to 54, 55 to 64, 65 to 74 and ≧ 75 were 89.4 ng/L, 126 ng/L, 206 ng/L, 386 ng/L and 522 ng/L, respectively. In females, the concentration of NT-proBNP at the same age was 132 ng/L, 229 ng/L, 262 ng/L, 297 ng/L and 807 ng/L, respectively. The repeatability precision coefficient of variation (CV%) for NT-proBNP was between 0.86 and 1.65 in analytical performance. In contrast, the reproducibility precision (CV%) for NT-proBNP was between 1.52 and 3.22, respectively. The study found a bias of accuracy of 3.73% in low-value samples (concentration: 148.69) and 7.31% in high-value samples (concentration: 1939.08). The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of 125 ng/L were 96.6%, 92.3%, 84.2%, and 98.5%, respectively. In contrast, those of 300 ng/L were 94.0%, 98.2%, 95.7% and 97.5%, respectively. CONCLUSIONS: The Mindray NT-proBNP assay showed increased levels in both males and females with age, with higher levels in women. It performs well and aligns with manufacturer specifications. We recommend adjusting cutoff values based on demographic factors.

Engineered Multifunctional Zinc-Organic Framework-Based Aggregation-Induced Emission Nanozyme for Accelerating Spinal Cord Injury Recovery.

Functional recovery following a spinal cord injury (SCI) is challenging. Traditional drug therapies focus on the suppression of immune responses; however, strategies for alleviating oxidative stress are lacking. Herein, we developed the zinc-organic framework (Zn@MOF)-based aggregation-induced emission-active nanozymes for accelerating recovery following SCI. A multifunctional Zn@MOF was modified with the aggregation-induced emission-active molecule 2-(4-azidobutyl)-6-(phenyl(4-(1,2,2-triphenylvinyl)phenyl)amino)-1H-phenalene-1,3-dione via a bioorthogonal reaction, and the resulting nanozymes were denoted as Zn@MOF-TPD. These nanozymes gradually released gallic acid and zinc ions (Zn2+) at the SCI site. The released gallic acid, a scavenger of reactive oxygen species (ROS), promoted antioxidation and alleviated inflammation, re-establishing the balance between ROS production and the antioxidant defense system. The released Zn2+ ions inhibited the activity of matrix metalloproteinase 9 (MMP-9) to facilitate the regeneration of neurons via the ROS-mediated NF-κB pathway following secondary SCI. In addition, Zn@MOF-TPD protected neurons and myelin sheaths against trauma, inhibited glial scar formation, and promoted the proliferation and differentiation of neural stem cells, thereby facilitating the repair of neurons and injured spinal cord tissue and promoting functional recovery in rats with contusive SCI. Altogether, this study suggests that Zn@MOF-TPD nanozymes possess a potential for alleviating oxidative stress-mediated pathophysiological damage and promoting motor recovery following SCI.

Virulence and Adhesion of the Treponema pallidum Nichols Strain Simultaneously Decrease in a Continuous-Infection New Zealand White Rabbit Model.

Syphilis is a sexually transmitted disease caused by T. pallidum, and the T. pallidum Nichols strain is widely used with the New Zealand white rabbit model for evaluating drug and vaccine protection. However, changes in the virulence of T. pallidum during transmission are still unknown. Herein, we explored the virulence of T. pallidum in the rabbit model of continuous infection through phenotype observation and further investigated the relationship between virulence and adhesion. During the construction of the syphilis rabbit model, the optimal dose of 104/site of T. pallidum was determined to effectively observe the depiction of syphilis lesions and immune responses for further virulence evaluation. Its virulence was gradually weakened during the interaction with host cells or the testicular passage, which was also proven using the pathological phenotype of the syphilis rabbit model. In addition, the adhesive ability of T. pallidum was reduced with increasing generation, which was verified via the co-incubation of the pathogen with Sf1Ep cells. This study provides insight into the relationship by which the virulence and adhesion of T. pallidum were decreased in a New Zealand white rabbit model of continuous infection and contributes to our knowledge regarding the development of syphilis.

Effects of Atractylodes lancea extracts on intestinal flora and serum metabolites in mice with intestinal dysbacteriosis.

OBJECTIVE: This study aims to explore the effect of an extract of Atractylodes lancea (A. lancea) on antibiotics-induced intestinal tract disorder and the probable therapeutic mechanisms employed by this extract to ameliorate these disorders. METHODS: Three days after acclimatization, nine male and nine female specific-pathogen-free (SPF) mice were randomly assigned into three groups: Group C (normal saline), Group M (antibiotic: cefradine + gentamicin), and Group T (antibiotic + A. lancea extract). Each mouse in Groups M and T received intragastric (i.g.) gavage antibiotics containing cefradine and gentamicin sulfate (0.02 ml/g-1/D-1) for 7 days. A. lancea extract (0.02 ml/g-1/D-1) was administered by i.g. gavage to Group T mice for 7 days following the cessation of antibiotic therapy. Group M received an equivalent volume of normal saline for 7 days, while Group C received an equivalent volume of normal saline for 14 days. Afterwards, we collected mouse feces to assess changes in intestinal microbiota by 16S ribosomal ribonucleic acid (rRNA) sequencing and metabolomics. In addition, serum samples were gathered and analyzed using liquid chromatography-mass spectrometry (LS-MS). Finally, we performed a correlation analysis between intestinal microbiota and metabolites. RESULTS: After treatment with antibiotic, the richness and diversity of the flora, numbers of wall-breaking bacteria and Bacteroidetes, and the numbers of beneficial bacteria decreased, while the numbers of harmful bacteria increased. After i.g. administration of A. lancea extract, the imbalance of microbial flora began to recover. Antibiotics primarily influence the metabolism of lipids, steroids, peptides, organic acids, and carbohydrates, with lipid compounds ranking first. Arachidonic acid (AA), arginine, and proline have relatively strong effects on the metabolisms of antibiotic-stressed mice. Our findings revealed that A. lancea extract might restore the metabolism of AA and L-methionine. The content of differential metabolites detected in the serum of Group T mice was comparable to that in the serum of Group C mice, but significantly different from that of Group M mice. Compared to putative biomarkers in the Kyoto Encyclopedia of Genes and Genomes (KEGG) database, it was found that altered metabolites, such as amino acids, glycerol, and phospholipids, were primarily associated with the metabolism. CONCLUSIONS: The effective mechanisms of A. lancea extract in regulating the disorder of intestinal flora in mice are related to the mechanisms of A. lancea. It could relate to lipid metabolism, bile acid metabolism, and amino acid metabolism. These results will provide a basis for further explaining the mechanism by which A. lancea regulats intestinal flora.

Analysis of factors associated with postoperative acute kidney injury in patients with colorectal cancer and the development of a risk prediction model: a retrospective study.

BACKGROUND: To investigate the factors associated with acute kidney injury (AKI) in postoperative colorectal cancer (CRC) patients and develop a risk prediction model. METHODS: The clinical data of 389 CRC patients were retrospectively analyzed. The patients were divided into AKI (n = 30) and non-AKI groups (n = 359) according to KDIGO diagnostic criteria. Demographic data, the presence of underlying diseases, perioperative conditions and related examination results were compared between the two groups. Binary logistic regression was used to analyze the independent risk factors for postoperative AKI, and a risk prediction model was established. And a verification group (94 patients) was used to verify the model. RESULTS: 30 patients (7.71%) with CRC had postoperative AKI. Binary logistic regression analysis showed that preoperative combined hypertension, preoperative anemia, inadequate intraoperative crystalloid infusion, low intraoperative minimum mean arterial pressure (MAP) and moderate to severe postoperative decline in hemoglobin (Hb) levels were independent risk factors. The risk prediction model developed was expressed as Logit P = - 0.853 + 1.228 * preoperative combined hypertension + 1.275 *preoperative anemia - 0.002 * intraoperative crystalloid infusion (ml) - 0.091 * intraoperative minimum MAP (mmHg) + 1.482 * moderate to severe postoperative decline in Hb levels. In Hosmer-Lemeshow test, χ2 = 8.157, P = 0.718 showed that the fitting effect was good. The area under ROC curve was 0.776 (95% CI 0.682-0.871, P < 0.001), with a prediction threshold of 1.570, a sensitivity of 63.3% and a specificity of 88.9%. The sensitivity and specificity of the verification group were 65.8% and 86.1%. CONCLUSIONS: Preoperative combined hypertension, preoperative anemia, inadequate intraoperative crystalloid infusion, low intraoperative minimum MAP, and moderate to severe postoperative decline in Hb levels were independent risk factors for AKI development in CRC patients. The prediction model can effectively predict the occurrence of postoperative AKI in patients with CRC.

Characterization of Chronic Hepatitis E Virus Infection in Immunocompetent Rabbits.

Chronic hepatitis E virus (HEV) infection is frequently reported in immunocompromised patients, but has also been increasingly reported in non-immunocompromised individuals. We characterized the course of chronic HEV infection in immunocompetent rabbits. In two independent experiments, 40 specific-pathogen-free rabbits were infected with a rabbit HEV genotype 3 strain in serial diluted titers (108 to 104 copies/mL). Serum and fecal samples were collected weekly and were tested for HEV RNA, antigen, anti-HEV and liver enzymes. Rabbits that spontaneously cleared the infection before 10 weeks post-inoculation (wpi) were kept to the end of the study as recovery control. Liver tissues were collected from HEV-infected rabbits at 5, 10 and 26 wpi for histopathological analysis. Nineteen rabbits (47.5%) developed chronic HEV infection with persistent viraemia and fecal HEV shedding for >6 months. Seroconversion to anti-HEV was observed in 84.2% (16/19) of the chronically infected rabbits. Serum levels of aminotransferase were persistently elevated in most of the rabbits. Characterizations of chronic HEV infection in immunocompetent settings could be recapitulated in rabbits, which can serve as a valuable tool for future studies on pathogenesis.

A deep learning-based system for assessment of serum quality using sample images.

BACKGROUND: Serum quality is an important factor in the pre-analytical phase of laboratory analysis. Visual inspection of serum quality (including recognition of hemolysis, icterus, and lipemia) is widely used in clinical laboratories but is time-consuming, subjective, and prone to errors. METHODS: Deep learning models were trained using a dataset of 16,427 centrifuged blood images with known serum indices values (including hemolytic index, icteric index, and lipemic index) and their performance was evaluated by five-fold cross-validation. Models were developed for recognizing qualified, unqualified and image-interfered samples, predicting serum indices values, and finally composed into a deep learning-based system for the automatic assessment of serum quality. RESULTS: The area under the receiver operating characteristic curve (AUC) of the developed model for recognizing qualified, unqualified and image-interfered samples was 0.987, 0.983, and 0.999 respectively. As for subclassification of hemolysis, icterus, and lipemia, the AUCs were 0.989, 0.996, and 0.993. For serum indices and total bilirubin predictions, the Pearson's correlation coefficients (PCCs) of the developed model were 0.840, 0.963, 0.854, and 0.953 respectively. Moreover, 30.8% of serum indices tests were deemed unnecessary due to the preliminary application of the deep learning-based system. CONCLUSIONS: The deep learning-based system is suitable for the assessment of serum quality and holds the potential to be used as an accurate, efficient, and rarely interfered solution in clinical laboratories.

Immune infiltration profiling in gastric cancer and their clinical implications.

The abundance and type of immune cells in the tumor microenvironment (TME) significantly influence immunotherapy and tumor progression. However, the role of immune cells in the TME of gastric cancer (GC) is poorly understood. We studied the correlations, proportion, and infiltration of immune and stromal cells in GC tumors. Data analyses showed a significant association of infiltration levels of specific immune cells with the pathological characteristics and clinical outcomes of GC. Furthermore, based on the difference in infiltration levels of immune and stromal cells, GC patients were divided into two categories, those with "immunologically hot" (hot) tumors and those with "immunologically cold" (cold) tumors. The assay for transposase-accessible chromatin using sequencing and RNA sequencing analyses revealed that the hot and cold tumors had altered epigenomic and transcriptional profiles. Claudin-3 (CLDN3) was found to have high expression in the cold tumors and negatively correlated with CD8+ T cells in GC. Overexpression of CLDN3 in GC cells inhibited the expression of MHC-I and CXCL9. Finally, the differentially expressed genes between hot and cold tumors were utilized to generate a prognostic model, which predicted the overall survival of GC as well as patients with immunotherapy. Overall, we undertook a comprehensive analysis of the immune cell infiltration pattern in GC and provided an accurate model for predicting the prognosis of GC patients.

cGAS regulates the DNA damage response to maintain proliferative signaling in gastric cancer cells.

The activation of some oncogenes promote cancer cell proliferation and growth, facilitate cancer progression and metastasis by induce DNA replication stress, even genome instability. Activation of the cyclic GMP-AMP synthase (cGAS) mediates classical DNA sensing, is involved in genome instability, and is linked to various tumor development or therapy. However, the function of cGAS in gastric cancer remains elusive. In this study, the TCGA database and retrospective immunohistochemical analyses revealed substantially high cGAS expression in gastric cancer tissues and cell lines. By employing cGAS high-expression gastric cancer cell lines, including AGS and MKN45, ectopic silencing of cGAS caused a significant reduction in the proliferation of the cells, tumor growth, and mass in xenograft mice. Mechanistically, database analysis predicted a possible involvement of cGAS in the DNA damage response (DDR), further data through cells revealed protein interactions of the cGAS and MRE11-RAD50-NBN (MRN) complex, which activated cell cycle checkpoints, even increased genome instability in gastric cancer cells, thereby contributing to gastric cancer progression and sensitivity to treatment with DNA damaging agents. Furthermore, the upregulation of cGAS significantly exacerbated the prognosis of gastric cancer patients while improving radiotherapeutic outcomes. Therefore, we concluded that cGAS is involved in gastric cancer progression by fueling genome instability, implying that intervening in the cGAS pathway could be a practicable therapeutic approach for gastric cancer.

microRNA-29b inhibits cell growth and promotes sensitivity to oxaliplatin in colon cancer by targeting FOLR1.

The present study was aimed to explore the functional role of microRNA (miR)-29b in colon cancer, as well as underlying mechanisms. Expressions of miR-29b and folate receptor 1 (FOLR1) were measured in both human colon tumor samples and cell lines. Colon cancer cell lines SW480 and SW620 were transfected with miR-29b mimic, antisense oligonucleotides (ASO)-miR-29b, small interfering (siRNA) against FOLR1 (si-FOLR1), or corresponding negative controls (NCs), and then were incubated with or without oxaliplatin (L-OHP). Thereafter, cell viability, cytotoxicity, cell apoptosis, and expression of FOLR1, ATP Binding Cassette Subfamily G Member 2 (ABCG2) and p-glycoprotein (p-gp) were analyzed. We found that miR-29b was significantly decreased, while FOLR1 was statistically elevated in colon cancer samples and cell lines compared to the nontumor samples and nontumourigenic immortalized human colon epithelial cell line FHC. Overexpression of miR-29b markedly inhibited cell viability, promoted sensitivity to L-OHP, stimulated cell apoptosis (all p < .05), and decreased the levels of ABCG2 and p-gp in cancer cells, whereas suppression of miR-29b showed contrary results. Moreover, we observed that FOLR1 was a direct target of miR-29b and was negatively regulated by miR-29b. In addition, the findings revealed that the effects of FOLR1 inhibition on cell viability, sensitivity to L-OHP, cell apoptosis, and the levels of ABCG2 and p-gp were similar to overexpression of miR-29b. Taken together, our study suggests that miR-29b inhibits cell growth and promotes sensitivity to L-OHP in colon cancer by targeting FOLR1.