ABSTRACT
Photorhabdus is a Gram-negative bacterium from the family Enterobacteriaceae that lives in a symbiotic association with nematode or insects. In addition to the role of being insect pathogens, one species called Photorhabdus asymbiotica (Pa) causes human infection around the world. Nevertheless, how does this transkingdom infection occur remains elusive. Here we focus on one pathogenic determinant called Photorhabdus virulence cassette (PVC) that is founded in the Pa genome and many other pathogens. The RNA-seq and qPCR data showed that the NF-κB and MAPK pathways were drastically activated in the PVC-treated mammalian macrophages. Western blotting assays using samples treated with various inhibitors of the affected pathways confirmed the results we have observed for MAPK pathway previously. p65 translocation assays validated the NF-κB activation in the macrophages after PVC treatment. Moreover, the bacterial phagocytosis by macrophage was also promoted by PVC at the early stage, and this phagocytosis was inhibited by cytoskeleton inhibitors. Thus, the results indicated that PVC is involved in the bacterial invasion by activating NF-κB and MAPK signaling pathway, providing a new perspective for analyzing the pathogenicity of Pa in human infections.
Subject(s)
Animals , Humans , Macrophages , NF-kappa B/genetics , Photorhabdus , Signal Transduction , VirulenceABSTRACT
Acute respiratory failure (ARF) is one primary cause of intensive care unit (ICU) admittance, which is usually treated with intubation and mechanical ventilation in order to maintain a necessary ventilation and oxygenation function. After the remove of trachea tube, available oxygenation supports include nasal cannula, venturi mask, non-invasive ventilator and high flow nasal cannula (HFNC). In this articlewe reviewed the physiological mechanism related to HFNC therapy and trails about the application of HFNC in extubated patients. HFNC can provide well heated and humidified high flow gas with a high concentration of oxygen, which can improve the oxygenation and degree of comfort of patients after extubation. Furthermore, HFNC can improve the prognosis of these patients. However, HFNC has little influence on non-ventilation related factor and severe dysfunction of ventilation, so its indication and risk factor of treatment failure should be further evaluated with randomize controlled trials.
ABSTRACT
Objective To monitor the association between the expression of ve-cadherin and mesentery microcirculation blood flow of sepsis CASP rats,Analysis the relationship of each other.Methods Based on the standard criteria,we established sepsis CASP rats,and the rats were divided into several groups according to the gauge of the vein detained needle in the ascending colon,every group has six rats.The groups consisted of Sepsis A group 22 G(0.9 mm× 25 mm,33 ml/min),sepis B group 20 G(1.1 mm ×32 mm,54 ml/min),sepsis C group 18 G(1.3 mm ×32 mm,80 ml/min),sepsis D group 14 G(2.0 mm ×45 mm,270 ml/min),in addition we established the control group.Real-time observation was performed by microscope on the 6 h's blood velcocity of each sepsis CASP rats group.Then we applied the immunohistochemistry to quantitatively analyze the expression of ve-cadherin of each group.Results The blood velcocity of the mesentery microcirculation in control group was (583.21 ±52.39) μm/s,it was higher compared with the sepsis D group(213.30 ±52.39) μm/s (P ＜0.05),the blood velocity in sepsis A group was (482.71 ± 58.62) μm/s,higher compared with the sepsis D group(P ＜ 0.05).The score of the immunohistochemistry quantitative analysis of mesentery ve-cadherin in control group was 11.17 ±0.34,higher compared with the sepsis D group(5.43 ±0.43)(P ＜0.01).The score of sepsis A group was 10.07 ±0.30,higher compared with the sepsis D group(P＜0.05).Conclusions The expression of ve-cadherin of sepsis CASP rats had positive correlation with the blood velocity of the mesentery microcirculation of sepsis CASP rats,and it can indirectly reflect the degree of the sepsis.