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Abstract To assess the effectiveness and safety of combining Saccharomyces boulardii powder with triple therapy as a primary approach for eradicating H. pylori infection, a total of 144 patients who tested positive for H. pylori and diagnosed with non-ulcer dyspepsia underwent endoscopy at two national centers between June 2017 and March 2019 were included. The patients were categorized into three groups using a subsection randomization method and received initial H. pylori eradication treatments. Microbial composition, eradication rates, symptom alleviation, and adverse reactions were monitored on the 14th and 44th days post-treatment. According to PP analysis showed the eradication rates for the SRAC group was 75%, BRAC was 93.18% and RAC was 65.2%. Group BRAC exhibited a marginally higher eradication rate compared to other groups. However, patients receiving Saccharomyces boulardii treatment exhibited an overall reduction in initial dyspepsia symptoms by the end of the treatment period. When employed as a primary strategy, the combination of Saccharomyces boulardii powder with triple therapy displayed notable efficacy and smaller gastrointestinal side effects in eradicating initial H. pylori infections among non-ulcer dyspepsia patients. Moreover, this approach demonstrated advantages in alleviating symptoms, exhibited favorable tolerance, and maintained a high level of clinical safety.

Background The tcdA gene codes for an important toxin produced by Clostridioides difficile (C. difficile), but there is currently no simple and cost-effective method of detecting it. This article establishes and validates a rapid and visual loop-mediated isothermal amplification (LAMP) assay for the detection of the tcdA gene. Methods Three sets of primers were designed and optimized to amplify the tcdA gene in C. difficile using a LAMP assay. To evaluate the specificity of the LAMP assay, C. difficile VPI10463 was used as a positive control, while 26 pathogenic bacterial strains lacking the tcdA gene and distilled water were utilized as negative controls. For sensitivity analysis, the LAMP assay was compared to PCR using ten-fold serial dilutions of DNA from C. difficile VPI10463, ranging from 207 ng/µl to 0.000207 pg/µl. The tcdA gene of C.difficile was detected in 164 stool specimens using both LAMP and polymerase chain reaction (PCR). Positive and negative results were distinguished using real-time monitoring of turbidity and chromogenic reaction. Results At a temperature of 66 °C, the target DNA was successfully amplified with a set of primers designated, and visualized within 60 min. Under the same conditions, the target DNA was not amplified with the tcdA12 primers for 26 pathogenic bacterial strains that do not carry the tcdA gene. The detection limit of LAMP was 20.700 pg/µl, which was 10 times more sensitive than that of conventional PCR. The detection rate of tcdA in 164 stool specimens using the LAMP method was 17% (28/164), significantly higher than the 10% (16/164) detection rate of the PCR method (X2 = 47, p < 0.01). Conclusion LAMP method is an effective technique for the rapid and visual detection of the tcdA gene of C. difficile, and shows potential advantages over PCR in terms of speed, simplicity, and sensitivity. The tcdA-LAMP assay is particularly suitable for medical diagnostic environments with limited resources and is a promising diagnostic strategy for the screening and detection of C. difficile infection in populations at high risk.

Abstract Secreted proteins are one of the direct molecular mechanisms by which microbiota influence the host, thus constituting a promising field for drug discovery. Here, through bioinformatics-guided screening of the secretome of clinically established probiotics from Lactobacillus, we identify an uncharacterized secreted protein (named LPH here) that is shared by most of these probiotic strains (8/10) and demonstrate that it protects female mice from colitis in multiple models. Functional studies show that LPH is a bi-functional peptidoglycan hydrolase with both N-Acetyl-β-D-muramidase and DL-endopeptidase activities that can generate muramyl dipeptide (MDP), a NOD2 ligand. Different active site mutants of LPH in combination with Nod2 knockout female mice confirm that LPH exerts anti-colitis effects through MDP-NOD2 signaling. Furthermore, we validate that LPH can also exert protective effects on inflammation-associated colorectal cancer in female mice. Our study reports a probiotic enzyme that enhances NOD2 signaling in vivo in female mice and describes a molecular mechanism that may contribute to the effects of traditional Lactobacillus probiotics.

The pre-swirl nozzles are a crucial part of gas turbine's cooling pre-swirl system, because they directly affect the cooling performance of the system and the life of the turbine blades. Vane-shaped pre-swirl nozzles, including cascade vane nozzles (VN) and vane-shaped hole nozzles (VSH) proposed in recent years, are reported to have higher system temperature drop potential. In this paper, the pre-swirl performance as well as the cooling effect of these two types of nozzles were studied and compared experimentally. A five-hole probe was used to measure the flow field at nozzle exits under the outlet conditions of Mach number 0.2 and 0.3, and the comparisons of global deviation angle and pre-swirl effectiveness were carried out. The variations of pre-swirl effectiveness (η) with aerodynamic parameters, such as pressure ratio and Reynolds number in the range of 3 × 104 to 8 × 105 were also obtained with the help from numerical simulations. The cooling performance of two nozzles were further tested by a system test rig with rotating parts downstream of the two nozzles. Total pressure and outlet flow angle at nozzle exit illustrate that VN have obvious boundary layer separation from the suction surface, and the secondary endwall flow loss is high due to their narrow flow passages. As a result, when Mach number is 0.2, the deviation angle for VN is about 3° and the pre-swirl effectiveness is only 0.77. Well-designed VSH have improved flow passages with appropriate height to pitch ratio and a smaller trailing edge, and they suppress boundary layer separation and secondary flow development. This contributes to a significantly lower deviation angle near 0°, and an increased pre-swirl effectiveness of 0.86. In addition, the pre-swirl effectiveness of these two vane shaped nozzles will first increase with Reynolds number and then tend to a constant at Reynolds number about 4 × 105 and beyond. The maximum effectiveness of VN is 0.85 and that of VSH is about 0.94 and is 10.6% higher. Meanwhile, the measured temperature drop effectiveness of the pre-swirl system with VSH reaches 0.49, achieving an 8.9% improvement over the system with VN at 0.45. These results are consistent with the theoretical linear relationship between system temperature drop and nozzle pre-swirl effectiveness. The investigations in this paper also conclude that the pre-swirl effectiveness of nozzles is a more accurate parameter in classifying the nozzle performance and system cooling effect than traditionally used discharge coefficient.

Background: The short half-life of TRAIL (tumor necrosis factor–related apoptosis-inducing ligand) greatly limits its clinical application. This study was aimed to improve its potency on liver fibrosis through PEG (polyethylene glycol) modification prolonging the half-life of TRAIL.Methods: PEG, TRAIL, and the chemically synthesized complex PEG-TRAIL were used to treat 3T3 and LX-2 cells and liver fibrotic mice. In vitro, cell viability, apoptosis, and fibrosis were investigated using CCK-8 (cell counting kit-8) assay, flow cytometry, and Western blotting, respectively. In vivo, Sirius red staining, immunohistochemistry, and α-SMA (α-smooth muscle actin)/TUNEL (terminal deoxynucleotidyl transferase dUTP [2'-deoxyuridine 5'-triphosphate] nick end labeling) double-labeling immunofluorescence (IF) were performed after various treatments for liver fibrotic mice. The fibrotic liver was subjected to DR4 (death receptor 4)/TRAIL double-labeling IF to assess the retention of TRAIL enhanced by PEGylation.Results: The cells treated with PEG-TRAIL showed lower cell viability, higher apoptosis level, and stronger anti-fibrotic effect compared with PEG or TRAIL treatment. In vivo, PEGylated TRAIL exhibited a longer circulation than TRAIL did. Compared with TRAIL treatment, PEG-TRAIL caused a significant reduction of α-SMA and a markedly increase of apoptotic aHSCs. PEGylation is more likely to prolong the retention of TRAIL in circulation and enhance the possibility to target aHSCs and DR4-positive (DR4+) cells in the liver.Conclusion: PEG-TRAIL presents better anti-fibrotic and proapoptotic effects, for which, the prolonged circulation half-life in vivo may account. The PEG-TRAIL may serve as a new clinical therapeutic for liver fibrosis in the future.

Disordered intestinal flora and discordant immune response are associated with the development of ulcerative colitis (UC). Recent work has described the ability of macrophages to undergo repolarization toward a proinflammatory M1 or anti-inflammatory M2 phenotype in response to particular bacterium-derived signals. Fusobacterium nucleatum (F. nucleatum, Fn) is a species of intestinal commensal bacteria with potential pathogenicity, but its association with UC and how it may contribute to progression of UC is largely unknown. In this study, we provide new evidence that F. nucleatum accumulated heavily in the intestine of UC patients and was accompanied by the secretion of IFN-γ and the skewing of M1 macrophages. Mechanistically, our data showed that F. nucleatum aggravated dextran sodium sulfate (DSS)-induced colitis in the production of Th1-related cytokines IFN-γ through the AKT2 signaling pathway in vitro and in vivo. To further confirm the disease-relevance of these shifts in macrophage repolarization in response to F. nucleatum, stimulated bone marrow-derived macrophages (BMDMs) were transferred into recipient mice with DSS colitis. This transfer resulted in increased disease activity and inflammatory cytokine production. Taken together, we show clearly that F. nucleatum can promote the progression of UC via proinflammatory M1 macrophage skewing, and targeting F. nucleatum or AKT2 signaling may be a viable means of blocking development of UC.