ABSTRACT
Portulaca oleracea L. (PO) is known as "a vegetable for long life" due to its antioxidant, anti-inflammatory, and other pharmacological activities. However, the protective activity of the ethanol extract of PO (EEPO) against hypoxia-induced pulmonary edema has not been fully investigated. In this study, we exposed mice to a simulated altitude of 7000 meters for 0, 3, 6, 9, and 12 h to observe changes in the water content and transvascular leakage of the mouse lung. It was found that transvascular leakage increased to the maximum in the mouse lung after 6 h exposure to hypobaric hypoxia. Prophylactic administration of EEPO before hypoxic exposure markedly reduced the transvascular leakage and oxidative stress, and inhibited the upregulation of NF-kB in the mouse lung, as compared with the control group. In addition, EEPO significantly reduced the levels of proinflammatory cytokines and cell adhesion molecules in the lungs of mice, as compared with the hypoxia group. Our results show that EEPO can reduce initial transvascular leakage and pulmonary edema under hypobaric hypoxia conditions.
Subject(s)
Altitude Sickness/metabolism , Phytotherapy , Plant Extracts/pharmacology , Portulaca/chemistry , Pulmonary Edema/drug therapy , Altitude Sickness/complications , Animals , Capillary Permeability/drug effects , Cell Adhesion Molecules/drug effects , Cytokines/drug effects , Lung/drug effects , Male , Mice , Mice, Inbred BALB C , NF-kappa B/drug effects , Oxidative Stress/drug effects , Pulmonary Edema/etiology , Pulmonary Edema/metabolism , Time FactorsABSTRACT
Objective This paper was performed to investigate the effectiveness of problem-based learning in naval hygiene teaching. Methods Totally 257 clinical medicine undergraduates and general practice undergraduates from Grade 2010 and 2009, Faculty of Naval Medicine, Second Military Medical University attended naval hygiene teaching. PBL and LBL approaches were applied in PBL group (Grade 2010, n=117) and LBL group (Grade 2009, n=140), respectively. The learning outcomes were evaluated by three tests covering PBL evaluation (or usually performance), theoretical examination and experimental practice . Questionnaire was used to investigate the recognition of PBL teaching method and new evaluation system. Data were analyzed by SPSS 16.0 and t test was used to compare the average scores of theory,α=0.05. Results The results showed that the average theory scores of Grade 2010 (78.51±7.57 and 71.68±5.74) were higher than those of Grade 2009 (65.36±6.41 and 59.97±7.08) (P=0.000, P=0.000). The questionnaire surveys indicated that more than 85% students in PBL group considered the PBL teaching method could enhance professional and comprehensive quali-ties, and that 84%students were satisfied with new evaluation system. Conclusions PBL showed better learning results than traditional methods in naval hygiene teaching and could better promoted students' comprehensive ability.
