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Objective To investigate the effects of G-CSF-mobilized autologous stem cells in the prevention of radiation pulmonary injury.Methods Mice were divided into control group,irradiation group and treatment group.Mouse model of pulmonary fibrosis was established by exposing chest to a single dose of 14 Gy.Animals in the treatment group received recombinant human G-CSF (250 μg/kg daily for 5 d) before the irradiation in order to mobilize autologous stem cells in vivo.The general condition and mortality were documented after radiation injury.The pathological study with histological scoring,Masson staining and Sirius red staining with polarized light analysis were used to identify lung injury and the potential benefit of stem cell mobilization.Results Local chest irradiation of a single dose of 14 Gy was a suitable dose to create radiation-induced pulmonary fibrosis in mice.The death rate was 37.5％,which mainly happened around 11 weeks after injury.In contrast,all of the animals in G-CSF treated group survived.The ratio of lung to body mass was significantly increased in both irradiation group and treatment group (F =23.20,P＜0.05) around 3 months after the injury,with a higher ratio in irradiation group than that in treatment group (P＜0.05).Histological scoring for alveolar inflammation at 3 months after injury revealed statistically significant difference in irradiation group and treatment group compared with control group (F=11.93,P＜ 0.05).At this time point,the pathological observation showed lung tissue degeneration and necrosis with alveolitis and interstitial inflammation,as well as fibroblasts proliferation and focal collagen deposition in alveolar septa.At 4 month after the injury,the inflammation ininterstitial tissue was receded,but fibrosis and collagen deposition were significantly increased.In addition,at 3 and 4 months afterinjury,the pulmonary fibrosis was aggravated in irradiation group (F=28.73,16.85,P＜0.05),and significantly alleviated in the treatment group (P＜0.05).The similar results were confirmed in collagen content analysis (IOD) by Sirius red staining and image analysis (F =17.70,17.79,P＜ 0.05).Conclusions Autologous mobilization of stem cells could prevent the death of radiation-injured animals possibly by alleviating early lung injury and interstitial inflammation as well as the late pulmonary fibrosis,suggesting a therapeutic potential of autologous stem cell mobilization in radiation pulmonary fibrosis.
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Objective To explore risk factors for surgical site infection(SSI) in colorectal surgery,and provide evidence for formulating measures for preventing SSI.Methods Patients who underwent colorectal surgery in the department of gastrointestinal surgery of a hospital from June 2013 to June 2016 were surveyed retrospectively,the related risk factors for SSI were analyzed by unconditional logistic regression analysis.Results Among 397 patients who underwent colorectal surgery,67 (16.88％) had SSI.Logistic regression analysis showed that smoking,low albumin,seniority of surgeons less than 5 years,irrational use of antimicrobial agents during perioperative period,and high National Nosocomial Infection Surveillance (NNIS) score were independent risk factors for SSI after colorectal surgery (all P＜0.05).Conclusion There are multiple risk factors for SSI after colorectal surgery,it is necessary to pay attention to it and formulate preventive measures,so as to reduce the occurrence of SSI effectively.
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Objective To construct the eukaryotic expression vector for mouse microRNA miR-21 and identification its expression activ-ity in 293 cells. Methods The genomic sequence containing pre-miR-21 was amplified from mouse genomic DNA by PCR and cloned into the pRC/CMV plasmid. The constructed recombinant plasmid pRC/CMV-mmu-miR-21 was transfected to 293 cells by lipofectamine 2000, and the stably transfected cells were screened with G418,from which total RNA was extracted for detecting the expression of mature miR-21 by northern blot. In the meantime,a luciferase report plasmid examing the activity of miR-21 named pmiR-21-Luc reporter was also construc-ted,and luciferase activity analysis indicated the product of pRC/CMV-mmu-miR-21 indeed had biological activity. Results Both restriction enzyme digestion analysis and sequencing proved the recombinant plasmids were constructed correctly. The miR-21 was highly expressed in the screened clones of 293 cells and it had good biological activity. Conclusion The eukaryotic expression plasmid of mouse miR-21 was successfully constructed,which laid the foundation of further investigation of the role of miR-21 during skin wound healing.
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Objective To study the clinical features and curative effect of hepatitis associated aplastic anemia (HAAA) in children of China.Methods Patients' records in China Biological Medicine Database (CBM-disc 1980-2011) and Wan Fang Database were reviewed.The clinical data of the children with newly diagnosed HAAA were respectively studied,including clinical manifestations,blood routine,bone marrow examination and viral serology results,as well as the treatment and clinical effect.Results A total of 50 children were confirmed as HAAA.There were 41 boys and 9 girls.The median age was 8.2 years(range 0.8 to 15.0 years) on diagnosis.The causes of hepatitis could not be identified.The median interval between hepatitis occurrence to blood cell reduction was 10 weeks.Twenty-two cases were diagnosed as severe aplastic anemia and 13 cases as very severe aplastic anemia.Fifteen children died within 1 month after diagnosis.In the immunosuppression treatment group,the percentage of overall responders was 69.2％,which was higher than that of the non-immunosuppression treatment group (18.5％) (x2 =9.920,P ＜ 0.01).Conclusions Severe HAAA is very common in school children,especially in boys.The children with HAAA have a higher early death rate.Immunosuppression therapy is effective if combined with androgenic hormone with an earlier diagnosis.
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Objective To investigate the effects of exosomes derived from breast cancer cell line MDA-MB-231 on proliferation of human umbilical cord vein endothelial cells (HUVECs), and evaluate the role of MAPK/ERK and PI3K/Akt signal transduction pathway during the process. Methods Exosomes were derived and purified from MDA-MB-231 by cryogenic ultracentrifugation and density gradient centrifugation. MTT assay was carried out for measurement of cell proliferation in HUVECs with exosome of 50, 100, 200 and 400μJLg/ml. The states of cell cycle of HUVECs co-cultured with 200μJLg/ml exosomes were detected by flow cytometry. The effects of 200μJLg/ml exosomes on the expression of ERK, Akt and phosphorylated ERK, Akt in HUVECs were detected with Western blotting. Results Exosomes derived from MDA-MB-231 significantly promoted HUVECs proliferation in a classical time- and dose-dependent manner. Flow cytometry revealed that, co-cultured with 200μJLg/ml exosomes for 24h, S-phase cells in HUVECs increased, while G1/S phase cells in HUVECs decreased. Western blotting showed that, co-cultured with 200μxg/ml exosomes for 24h, 48h and 72h, the expressions of phosphorylated ERK and Akt were up-regulated in a time-dependent manner. Conclusion Exosomes derived from breast cancer cell line MDA-MB-231 may promote HUVECs proliferation, the changes in cell cycle and the continuous activation of the MAPK/ERK and PI3K/Akt signal transduction pathways may be the underlying mechanism.