MAM7 from Vibrio parahaemolyticus: Expression, purification and effects on RAW264.7 cells.

V. parahaemolyticus is a Gram-negative bacterium that causes gastroenteritis. Within the realm of bacterial interactions with the gut, the outer membrane protein MAM7 plays a key role. However, the precise function of MAM7 in intestinal inflammation, particularly its interactions with macrophages, remains unclear. In this study, we successfully expressed and purified recombinant MAM7. After optimization of the MAM7 expression condition, it was found that the optimal concentration and temperature were 0.75 mM and 15 °C, respectively, resulting in a 27-fold increase in its yield. Furthermore, RAW264.7 cytotoxicity assay was conducted. The CCK-8 results revealed that MAM7 substantially stimulated the proliferation of RAW264.7 cells, with its optimal concentration determined to be 7.5 µg/mL. Following this, the NO concentration of MAM7 was tested, revealing a significant increase (p < 0.05) in NO levels. Additionally, the relative mRNA levels of IL-1ß, IL-6, and TNF-α in RAW264.7 cells were measured by qRT-PCR, showing a remarkable elevation (p < 0.05). Moreover, ELISA results demonstrated that MAM7 effectively stimulated the secretion of IL-6 and TNF-α by RAW264.7 cells. In summary, these findings strongly suggest that MAM7 serves as a proinflammatory adhesion factor with the capacity to modulate immune responses.

Effectiveness of musculoskeletal manipulations in patients with neck pain: a protocol for a systematic review and network meta-analysis.

INTRODUCTION: Neck pain is a common problem that severely affects physical and mental health. While musculoskeletal manipulations are recommended as the first-line treatment for adults with neck pain, the comparative effectiveness of different musculoskeletal manipulations remains unclear. This systematic review and network meta-analysis of randomised controlled trials (RCTs) will compare the effectiveness of different types of musculoskeletal manipulations, with the overarching aim of guiding clinical practice. METHODS AND ANALYSIS: Two independent reviewers will search four English electronic databases (Web of Science, Cochrane Library, EMBASE, PubMed) and three Chinese electronic databases (China National Knowledge Infrastructure, China Science and Technology Journal Database, Wanfang) for relevant RCTs published from 1 January 2013 to 30 April 2023. The Clinical Trials Registry (ClinicalTrials.gov) will be searched for completed but unpublished RCTs. English and Chinese will be used to search English databases and Chinese databases, respectively. RCTs of musculoskeletal manipulations for adults (aged ≥18 years) with neck pain will be considered eligible for inclusion. A pairwise meta-analysis and network meta-analysis will be performed, and pooled risk ratios, standardised mean differences and 95% CIs will be determined. ETHICS AND DISSEMINATION: Ethics approval is not required as this study is a literature review. The results of this review will be published in peer-reviewed journals or disseminated at conferences. PROSPERO REGISTRATION NUMBER: CRD42023420775.

Identification of a potential antigen stimulating immune response against Vibrio parahaemolyticus infection in hybrid tilapia (Oreochromis aureus♂ × Oreochromis niloticus♀).

Vibrio parahaemolyticus (V. parahaemolyticus) is a major pathogen that causes substantial losses in the marine fishery. With the emergence of antibiotic resistance, vaccines have become the most effective approach against V. parahaemolyticus infection. Adhesion factors on the cell surface are pivotal in the colonization and pathogenesis of V. parahaemolyticus within the host, highlighting their potential as vaccine candidates. This study aims to assess the immunogenicity and potential of recombinant V. parahaemolyticus MAM7 (rMAM7) as a vaccine candidate. Initially, we cloned and purified the MAM7 protein of V. parahaemolyticus. Moreover, after 4 weeks of vaccination, the fish were challenged with V. parahaemolyticus. rMAM7 demonstrated a certain protective effect. Immunological analysis revealed that rMAM7 immunization-induced antibody production and significantly increased acid phosphatase (ACP) and alkaline phosphatase (AKP) activity in hybrid tilapia. Furthermore, serum bactericidal tests demonstrated a lower bacterial survival rate in the rMAM7 group compared to PBS and rTrxa. qRT-PCR results indicated that rMAM7 significantly upregulated CD4, CD8 and IgM gene expression, suggesting the induction of Th1 and Th2 responses in hybrid tilapia. Overall, these findings highlight the potential application of MAM7 from V. parahaemolyticus in the development of protein vaccines.

Spatial distribution characteristics of plasma plume on attenuation of laser radiation under subatmospheric pressure.

The attenuation of a laser by plasma plume can be restrained for laser welding under subatmospheric pressure. Based on the experimental obtained spectra, the extinctions of a probe laser under different subatmospheric pressures and the spatial distribution of probe laser extinction were measured. The role of subatmospheric pressure on plasma plume was analyzed. The results show that, with decreasing ambient pressure, the extinction of a probe laser decreases, and the welding penetration depth increases. The maximum attainable value of extinction gets far away from the keyhole in the transversal and vertical directions. The attenuation of a fiber laser is about 10% under normal atmosphere, and it reaches only about 1% when the ambient pressure is reduced to 3 kPa.