ABSTRACT
Objective:To establish mice models of Staphylococcus aureus bloodstream infections so as to investigate the inflammatory responses and histopathological changes in bloodstream infections (BSIs) mice.Methods:C57BL/6 mice were inoculated with S.aureus intravenously or intraperitoneally to induce BSIs.Survival rate , weight loss and murine sepsis scores ( MSS ) were ob-served.Blood samples and tissue homogenates were plated on agar to determine bacterial burden .Inflammatory proteins ( CRP,PCT) and cytokines ( IL-1β, IL-6 and TNF-α) were determined by ELISA kits.Histopathologic changes were also assessed by pathological inflammation scores(PIS),macroscopic and microscopic examination.Results: About 70% survival rate was observed in 4.5×108 CFU/ml S.aureus induced BSIs mice.Body weight decreased and sepsis scores increased significantly since 24 h post-infection in BSIs mice,and more prominent in IV group.The counts of WBC began to significantly increase at 3 h post-infection,while CRP and PCT levels peaked at 48 hours in IV and IP groups ( 60.80 ±5.63 vs 40.58 ±7.54 for CRP;6.796 ±1.16 vs 2.740 ±0.36 for PCT ) . Moreover,the levels of IL-1β,IL-6 and TNF-αin serum and tissue homogenates ( liver,lungs,and kidneys ) were significantly elevated in BSIs mice.Pathological changes in tissues (liver,lungs and kidneys) and higher pathological inflammation scores (PIS) were also observed in BSIs mice.Conclusion:Our study represents an effective approach for S.aureus BSIs model to mimic human sepsis.Our results demonstrated that inflammation protein (PCT,CRP) and cytokines(IL-6,IL-1βand TNF-α) play an important role in the in-flammatory response and histopathological changes during BSIs caused by S .aureus.
ABSTRACT
Objective To study the capacity of dentifrice containing hydroxyapatite (HA) particles with various grain sizes on the sorption of Cu (Ⅱ) ion from aqueous solution. Methods Three groups of dentifrice suspensions containing 3% HA particles with 60 nm grain size, 3% HA particles with 12 μm grain size, and blank dentifrice were prepared with serial concentrations. Copper ion solutions with initial concentration of 4.0 mg/L were mixed with dentifrice suspensions respectively and then been kept still for 24 hours. The residual copper ion concentration of the supernatant was measured by inductively coupled plasma emission spectrometer and the sorption rate of copper ion was calculated. Results The residual copper ion concentration of the supernatant decreased with increase of the concentration of dentifrice suspensions. The sorption rate of copper ion of dentifrice containing 60 nm HA was highest among the three groups. Conclusion Nano HA should be added into dentifrice to enhance the sorption capacity of copper ion from aqueous solution.