RESUMEN
【Objective】 To explore the plasma-activated medium (PAM) produced by low temperature plasma (LTP) on the proliferation and angiogenesis of human umbilical vein endothelial cells (HUVECs) so as to provide theoretical basis for the future use of PAM to promote wound healing and inhibit tumor angiogenesis. 【Methods】 HUVECs were selected as the in vitro research model. The PAM-containing medium after LTP treatment for different time points (0 s, 15 s, 30 s, 45 s, 60 s, and 75 s) was used for intervention. The influence of PAM on HUVECs viability was assessed using the MTT assay and cell cycle analysis. The effects of PAM on angiogenesis were examined through angiogenesis experiments. Intracellular levels of reactive oxygen species (ROS) were measured using fluorescence probes. A melanoma mouse model was established, and CD31 expression was detected by immunohistochemistry. 【Results】 As the treatment time increased, the intracellular levels of ROS also elevated. PAM derived from LTP exhibited a bidirectional effect on angiogenesis in HUVECs. Compared to the control group (0 s), low-dose treatments (15 s and 30 s) enhanced HUVECs viability, while high-dose treatments (45 s, 60 s, and 75 s) significantly decreased cell viability (P<0.05). The proportion of HUVECs in the S phase was significantly increased in the PAM-15 s and PAM-30 s groups, but markedly decreased in the PAM-45 s, PAM-60 s, and PAM-75 s groups, with statistically significant differences (P<0.05). The HUVECs tube formation ability was enhanced in the 15 s and 30 s PAM groups, but diminished in the PAM-45 s, PAM-60 s, and PAM-75 s groups, characterized by the decreased numbers of vascular nodes, intersections, meshes, and branching points (P<0.05). After PAM treatment in the melanoma mouse model, the control group exhibited widespread distribution of CD31 in tumor tissue, while the PAM-5 min and PAM-10 min groups displayed reduced distribution of CD31. 【Conclusion】 Short-term exposure to PAM enhances HUVECs proliferation and angiogenesis, whereas prolonged exposure suppresses cell viability and inhibits angiogenesis.
RESUMEN
【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.
RESUMEN
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.
RESUMEN
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 10s, 20s, 30s, 40s and 50s 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 10s, 20s, 30s, and 40s showed significant daily improvement and almost complete closure at days 12, 10, 7, 13, respectively.However, the wounds with plasma treatment time of 50s 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 30s 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.