Biological characteristics of Escherichia coli phage and Staphylococcus aureus phage isolated from sewage / 西安交通大学学报(医学版)

【Objective】 Escherichia coli phage (ECP) and Staphylococcus aureus phage (SAP) isolated from sewage were used as research objects, and their biological characteristics were analyzed to provide new experimental materials for the application of phages. 【Methods】 ECP and SAP were purified and cultured by double-layer agar method. Then a series of biological characteristics of these two phages were preliminarily analyzed by electron microscope observation, optimal multiplicity of infection (MOI) test, one-step growth curve test, temperature, pH, chloroform and ultraviolet sensitivity tests, respectively. 【Results】 The results of biological characteristics showed that ECP and SAP were both virulent phages, belonging to myoviridac family. Their optimal MOI was 10-1, and they had strong resistance to ultraviolet light. The cleavage volume of ECP was 76.3 PFU/cell, while that of SAP was 8.3 PFU/cell. ECP had a wide range of temperature tolerance and could stably survive at 30-50 ℃, while SAP was more sensitive to temperature and could be completely inactivated at 50 ℃ for 1 h. ECP could maintain a good lysis activity in the range of pH 5-11, while SAP in the range of pH 6-9. ECP had strong resistance to chloroform and was non-membranous phage, while SAP was more sensitive to chloroform and was a membranous phage. 【Conclusion】 ECP and SAP are both virulent phages and have strong resistance to ultraviolet light. The lysability, temperature, pH, and chloroform tolerance of ECP are stronger than those of SAP.

Research progress in molecular mechanism of blast lung injury / 中华创伤杂志

Lung is one of the most sensitive target organs of human beings under the shock waves. Due to its serious injury, rapid development and high mortality, blast lung injury has been a widely concerned research topic in the field of military medicine. In the normal physiological state, the body is in a dynamic balance between pro-inflammaton and anti-inflammation, oxidation and anti-oxidation, promoting apoptosis and inhibiting apoptosis. While blast lung injury breaks the balance and causes physiological, biochemical and pathological changes in the body, seriously leading to acute respiratory distress syndrome and multiple organ dysfunction syndrome, and eventually the mortality. So far, the researches on blast lung injury mainly involve damage model, pathogenesis, pathological changes, intervention treatment and so on, which has achieved great research findings. In the review, the authors summarize the progress of molecular mechanism for blast lung injury from the perspective of inflammatory reaction, oxidative stress, apoptosis and so on, which may promote the discovery of new targets for the diagnosis, treatment and rehabilitation intervention of blast lung injury.

Effect of low-temperature plasma on wound healing of mouse skin / 西安交通大学学报(医学版)

Objective To compare the different doses of low-temperature plasma (LTP) on wound healing in BALB/c mice so as to discuss the effects of the optimal dose of low-temperature plasma dealing with wound in mice and the acting mechanism of wound healing.Methods Adoptatmospheric pressure plasma jet discharged by the dielectric barrier was used to treat mouse skin wound.According to the processing time, the wounds were divided into 10s, 20s, 30s, 40s and 50s experimental groups, while naturally healing wounds served as negative controls and the wounds dealt with recombinant human epidermal growth factor served as positive controls.We recorded the wound size every day, observed the histopathological changes, the expression level of type Ⅰ collagen by immunofluorescence, and analyzed the composition of low-temperature plasma jet.Results The wounds with plasma treatment time of 10s, 20s, 30s, and 40s showed significant daily improvement and almost complete closure at days 12, 10, 7, 13, respectively.However, the wounds with plasma treatment time of 50s remained unhealed atday 14.The wounds in positive control group all healed, and the wound healing effect in positive control group could be achieved in 30s group.HE staining and immunofluorescence staining assays showed the optimal result of epidermal cell regeneration, granulation tissue hyperplasia, and collagen deposition in histological aspect at day 7 in 30 s group.The low-temperature plasma jet contained highly reactive free radicals of nitrogen and oxygen, which play an important role in wound healing process.Conclusion Appropriate doses of cold plasma can accelerate wound healing whereas over-doses of plasma can suppress wound healing.The process of wound healing may be related to reactive oxygen and nitrogen species in LTP.