Pathogen detection via inductively coupled plasma mass spectrometry analysis with nanoparticles.

Infections caused by viruses and bacteria pose a significant threat to global public health, emphasizing the critical importance of timely and precise detection methods. Inductively coupled plasma mass spectrometry (ICP-MS), a contemporary approach for pathogen detection, offers distinct advantages such as high sensitivity, a wide linear range, and multi-index capabilities. This review elucidates the underexplored application of ICP-MS in conjunction with functional nanoparticles (NPs) for the identification of viruses and bacteria. The review commences with an elucidation of the underlying principles, procedures, target pathogens, and NP requirements for this innovative approach. Subsequently, a thorough analysis of the advantages and limitations associated with these techniques is provided. Furthermore, the review delves into a comprehensive examination of the challenges encountered when utilizing NPs and ICP-MS for pathogen detection, culminating in a forward-looking assessment of the potential pathways for advancement in this domain. Thus, this review contributes novel perspectives to the field of pathogen detection in biomedicine by showcasing the promising synergy of ICP-MS and NPs.

[Mechanisms of Helicobacter pylori Intracellular Infection and Reflections Concerning Clinical Practice]. / å¹½é—¨èžºæ†èŒèƒžå† æ„ŸæŸ“æœºåˆ¶ä¸Žä¸´åºŠæ€è€ƒ.

Helicobacter pylori (H. pylori), for a long time, has generally been considered an extracellular bacterium. However, recent findings have shown that H. pylori can gain entry into host cells, evade attacks from the host immune system and the killing ability of medication, form stable intracellular ecological niche, and achieve re-release into the extracellular environment, thus causing recurrent infections. H. pylori intracellular infection causes cellular signaling and metabolic alterations, which may be closely associated with the pathogenesis and progression of tumors, thereby presenting new challenges for clinical eradicative treatment of H. pylori. Herein, examining this issue from a clinical perspective, we reviewed reported findings on the mechanisms of how H. pylori achieved intracellular infection, including the breaching of the host cell biological barrier, immune evasion, and resistance to autophagy. In addition, we discussed our reflections and the prospects of important questions concerning H. pylori, including the clinical prevention and control strategy, intracellular derivation, and the damage to host cells.

Inhibitory and Injury-Protection Effects of O-Glycan on Gastric Epithelial Cells Infected with Helicobacter pylori.

Helicobacter pylori (H. pylori) is an important pathogen that can cause gastric cancer. Multiple adhesion molecules mediated H. pylori adherence to cells is the initial step in the infection of host cells. H. pylori cholesterol-α-glucosyltransferase (CGT) recognizes and extracts cholesterol from cell membranes to destroy lipid raft structure, further promotes H. pylori adhesion to gastric epithelial cells. O-Glycan, a substance secreted by the deep gastric mucosa, can competitively inhibit CGT activity and may serve as an important factor to prevent H. pylori colonization in the deep gastric mucosa. However, the inhibitory and injury-protection effects of O-Glycan against H. pylori infection has not been well investigated. In this study, we found that O-Glycan significantly inhibited the relative urease content in the coinfection system. In the presence of O-glycan, the injury of GES-1 cells in H. pylori persistent infection model was attenuated and the cell viability was increased. We use fluorescein isothiocyanate-conjugated cholera toxin subunit B (FITC-CTX-B) to detect lipid rafts on gastric epithelial cells and observed that O-glycan can protect H. pylori from damaging lipid raft structures on cell membranes. In addition, transcriptome data showed that O-glycan treatment significantly reduced the activation of inflammatory cancer transformation pathway caused by H. pylori infection. Our results suggest that O-Glycan is able to inhibit H. pylori persistent infection of gastric epithelial cells, reduce the damage caused by H. pylori, and could serve as a potential medicine to treat patients infected with H. pylori.

[Sensitivity Comparison Experiment of Four Testing Methods for Helicobacter pylori].

Objective: To measure with standard microbiology methods the sensitivity of 4 commonly used testing methods for Helicobacter pylori (Hp) and to conduct a comparative study of the correlations and differences across the 4 methods. Methods: With the Hp standard strain (SS1) as the reference, colony forming units (CFU) as the units of quantitative analysis for detection performance, and gradient dilution of SS1 suspension as the simulation sample, we measured the sensitivity of 4 Hp testing methods, including bacterial culture, rapid urease test, antigen test, and quantitative fluorescent PCR. CFU values at different concentrations corresponding to the 4 commonly used Hp testing methods were documented and the correlations and differences were analyzed accordingly. Results: The sensitivity of Hp bacterial culture, rapid urease test, antigen test and quantitative fluorescent PCR was 2.0×10 CFU/mL, 2.0×10 5 CFU/mL, 2.0×10 5 CFU/mL, and 2.0×10 2 CFU/mL, respectively. Conclusion: The testing turnover time and sensitivity of different laboratory methods for Hp testing varied significantly. The quantitative fluorescent PCR and bacterial culture both showed relatively high sensitivity, but bacterial culture has complicated operation procedures and is too time-consuming. The rapid urease test and antigen test both were simple and quick to perform, but showed low sensitivity. For clinical and laboratory testing of Hp, appropriate testing method that can identify the corresponding changes of Hp should be selected according to the actual testing purpose.

Role of lipid rafts in persistent Helicobacter pylori infection: a narrative review.

Background and Objective: The distribution of components in the cell membrane is not uniform, but is organized into specific functional microdomains, known as "lipid rafts". These lipid rafts consist of cholesterol, sphingolipids, and various proteins. Studies have shown that lipid rafts contain multiple proteins that are closely related to signal transduction and immune response. Furthermore, lipid rafts are the sites where a variety of pathogens invade the cells, and are associated with the persistent infection of some pathogens, especially Helicobacter pylori (Hp). We are going to explore a new method to treat Hp by discussing the important role of lipid rafts in Hp persistent infection. Methods: Papers on lipid rafts were retrieved to analyze the evolution of the definition of lipid raft, research techniques, and studies on the correlation of lipid rafts with pathogens infecting host cells. Key Content and Findings: Hp uses cholesterol-α-glucosyltransferase (CGT) to extract cholesterol from the lipid rafts of host cell membrane and destroys the integrity of the lipid rafts, which contributes to its immune escape; Using drugs to inhibit the destruction of lipid rafts by CGT can inhibit the growth of Hp and help the body clear Hp. Conclusions: Lipid rafts are key to persistent Hp infection, and a new field of research on pathogen-host cell interactions and signal transduction. Researches on lipid rafts may promote a new breakthrough in the field of treatment of Hp.

Study on the preparation and function of regulatory T cells from human peripheral blood.

BACKGROUND: Regulatory T cells (Tregs) are an important cell subgroup of CD4+ T cells. Treg cells are critically involved in inducing immune tolerance, maintaining immune environment homeostasis, and preventing the occurrence of autoimmune diseases. Under normal conditions, the number of Tregs in the body is very small. This research was designed to establish an effective method to expand human peripheral blood Tregs in vitro and to analyze phenotype, purity, and function of Treg cells post-expansion. METHODS: Peripheral blood was obtained from healthy donors. CD4+CD25+CD127dim/- Treg cells were isolated from peripheral blood mononuclear cells (PBMCs) by magnetic-activated cell sorting (MACS), and an optimized culture system was used for amplification. The in vitro amplification ability of Treg cells was evaluated to determine the expression and purity of Treg cell-specific surface markers in different culture cycles. The suppressive function of Treg was determined by in vitro lymphocyte proliferation assay. RESULTS: Treg cells could be successfully isolated by magnetic activated cell sorting (MACS). After 21 days of in vitro culture, the mean expansion fold was 2,009±452.2 in ≤60 years, and there was a significant difference between the younger group and the older than 60 years group (1,238±330.0). Flow cytometry analysis revealed that the percentages of CD4+CD25+ cells and FOXP3+ cells were (93.25±3.05)% and (94.19±4.21)% on day 14, and (92.86±4.36)% and (91.55±5.62)% on day 21, respectively. In addition, the proportions of CD8+ T, CD19+ B, CD3-CD56+ natural killer cell (NK), and CD3+ CD56+ natural killer T cell (NKT) were extremely low. Lymphocyte proliferation assay demonstrated that Tregs could inhibit the proliferation of CD8+ T cells more effectively than that of CD4+ T cells. Furthermore, the suppressive capacity of Tregs was correlated with Treg-to-PBMCs ratios. CONCLUSIONS: We successfully established a technical protocol for manufacturing a large quantity of Tregs with high efficiency in vitro. The expanded Tregs have a steady FOXP3 expression and exhibited a potent immune suppression, which might have great significance in adoptive Treg therapy for treating graft-versus-host disease and autoimmune diseases.

[Preparation and Release Properties of Helicobacter pylori Recombinant Protein PLGA Microspheres and PLGA-Chitosan Microspheres].

OBJECTIVE: To preparethe poly lactic-co-glycolic acid (PLGA) microspheres and PLGA-chitosan microspheres containing Helicobacter pylori recombinant protein, namely the BIB protein, and to explore their optimal preparation parameters and in vitro release performance in gastric and intestinal fluids. METHODS: Double emulsions (water-in-oil-in-water, or W1/O/W2) solvent evaporation method was used to prepare the BIB-PLGA microspheres and the BIB-PLGA-chitosan microspheres. Univariate analysis was done to study the impact of the water-to-oil ratio (W1/O), PLGA mass fraction and PVA concentration on the morphology, particle size, polydispersity index (PDI), encapsulation efficiency (EE), and drug loading (DL) so as to identify the optimal parameters. Bicinchoninic acid (BCA) assay was used to determine the protein concentration and the release efficiency of BIB. RESULTS: The optimal preparation parameters identified in the study were as follows: W1/O at 1∶2, PLGA mass fraction at 5%, and PVA mass fraction at 0.2%. The BIB-PLGA microspheres were found to be (2.11±0.08) µm in particle size, 0.35±0.18 in PDI, (78.20±1.73)% in EE and (10.58±0.23)% in DL. The BIB-PLGA-chitosan microspheres were (2.28±0.52) µm in particle size, 0.39±0.54 in PDI, and (78.87±1.30)% and (15.50±0.25)% in EE and DL, respectively. Both BIB-PLGA microspheres and BIB-PLGA-chitosan microspheres showed slow-release property in gastric and intestinal fluids in vitro, with BIB-PLGA-chitosan microspheres showing better slow-release performance. CONCLUSION: The BIB-PLGA microspheres and BIB-PLGA-chitosan microspheres prepared with the double emulsions solvent evaporation method showed high DL and EE, controllable particle sizes, dispersive appearance, and slow-release property in gastric and intestinal fluids in vitro.

Anti-bacterial and anti-viral effects of Fengreqing oral liquid () in vitro and in vivo.

OBJECTIVE: To investigate the anti-bacterial and anti-viral effects of Fengreqing oral liquid (, FRQ) in vitro and in vivo. METHODS: The minimum inhibitory concentrations of Fengreqing Oral Liquid against six gram-positive bacteria (Staphylococcus aureus, Streptococcus mutans, Peptostreptococcus anaerobius, Hemolytic streptococcus, Streptococcus pneumoniae, Klebsiella pneumoniae), seven gram-negative bacteria (Escherichia coli, Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, Haemophilus influenzae, Helicobacter pylori, Pseudomonas aeruginosa, Gardnerella vaginalis) and Candida albicans were detected by the paper disc diffusion method. The inhibition rate of A/PuertoRico/8/34(H1N1) (PR8) influenza virus in different concentrations of Fengreqing oral solution was detected by chicken embryo method. CCK8 method was used to detect the half-cell infection of RSV, VSV and CVB3. The effect of FRQ on the survival curve of mice was detected by using co-infection model of Streptococcus pneumoniae and influenza virus. RESULTS: In vitro, FRQ can inhibit Actinobacillus actinomycetemcomitans, Helicobacter pylori, Gardnerella vaginalis, Staphylococcus aureus, Streptococcus mutans and Streptococcus pneumoniae and has an antiviral effect on the envelope virus H1N1. In vivo, Fengreqing oral solution had therapeutic effect on influenza-Streptococcus pneumoniae co-infection in mice, significantly improving the survival rate of mice. The medium dose and low dose FRQ significantly prolonged the survival time of mice. CONCLUSION: FRQ has good anti-bacterial and anti-viral effectsin vivo and in vitro.