ABSTRACT
With the development of higher education reform, cultivating students' practice ability and innovation consciousness has become the key task of experimental teaching . Aimed at training innovative talent, human anatomy department of Mudanjiang Medical University took mea-sures to reform practical contents of human anatomy such as introduction of animal organs, development of scientific research, and by setting the abundant practical teaching content and appraisal method, constructed the anatomy practice teaching system based on cultivating the innovation ability of medical students, which stimulated the enthusiasm of students for anatomy and improved quality of human anatomy teaching.
ABSTRACT
BACKGROUND: The pathological characteristics of pulmonary interstitial fibrosis are the proliferation of a large number of fibroblasts and the increasing deposition of matrix collagen that takes the place of normal lung structure. Fluvastatin can inhibit the proliferation of fibroblasts and many other cells.OBJECTIVE: To investigate the effects of fluvastatin in inhibiting the proliferation of rat lung fibroblasts cultured in vitro and its influence on bleomycin-induced pulmonary fibrosis and ventilation function.DESIGN: A randomized controlled trial.SETTING: Department of Respiratory Diseases, Xijing Hospital, Fourth Military Medical University of Chinese PLA; Teaching and Research Section of Pathology, Department of Basic Medicine, Fourth Military Medical University of Chinese PLA; Research Institute ofOrthopedics, Xijing Hospital,Fourth Military Medical University of Chinese PLA.PARTICIPANTS: The study was conducted in the laboratory of Department of Respiratory Diseases, Xijing Hospital of Fourth Military Medical University of Chinese PLA from January to December 2001. Thirty-one healthy adult male Sprague-Dawley(SD) rats of grade Ⅰ were selected in this study.INTERVENTIONS: The fibroblasts derived from the lung normal of one rat were cultured in vitro in media containing fluvastatin. The effect of fluvastatin on the growth curve and the effect of its different concentrations(0, 1 × 10-7,1 ×10-6, 1 ×10-5, 1 ×10-4, 1 ×10 3and 1 ×10-2 mol/L, fluvastatin of 0 mol/L was taken as the blank control group) in inhibiting the cultured cells were observed with MTT colorimetry. The effect of fluvastatin on the division index of the fibroblasts was analyzed by direct cell counting Hydroxyproline colorimetry was used to detect the influence of fluvastatin on the collagen secretion in the media. The other 30 SD rats were divided into six groups: normal control group, bleomycin-induced group and fluvastatin-treated groups(TH 1,TE1, TH15 and TL15 groups) named according to the date of giving fluvastatin,i. e. the 1st day and the 15th day, after the rats were given bleomycin A5. All the rats were killed 28 days later. The number of fibroblasts, the thickness of alveolar wall and the area of mesenchyma in lung tissue were measured by HE staining. The extracellular matrix and collagen in lung tissue were observed by Masson and sirius red staining, and hydroxyproline in lung tissue homogenates was measured.MAIN OUTCOME MEASURES: Fibroblast growth curve and division index of rat lung, hydroxyproline in the media and lung tissue homogenates,number of fibroblasts and the thickness of alveolar wall, the area of mesenchyma, extracellular matrix and collagen contents in lung tissue.RESULTS: Fluvastatin could inhibit the proliferation of the rat lung fibroblasts cultured in vitro(t=4.20 to 17.52, P < 0.01), and its inhibitory effect was increased with the increased dose of fluvastatin, which showed a dose-dependent effect. The 1 × 10-4 mol/L fluvastatin could completely inhibit the proliferation of the cultured cells, and the A490 value from the 2nd day on the fibroblasts by MTT colorimetry was not insignificantly different from those on the 1st day( P > 0.05) . The division index of the fibroblasts and secretion of collagen were obviously decreased by fluvastatin( t = 8. 037,P <0.01; t =3.99 to 10. 84, P <0.05 or P <0.01). In vivo, the number of fibroblasts, the thickness of lung alveolar wall, the area of mesenchyma and the content of hydroxyproline in lung tissue were significantly higher in bleomycin group than in control group( t =4. 62 to 11.93, P < 0. 01), while those in the fluvastatin-treated groups were lower than those in bleomycin group in different degrees( t = 2.69 to 7.65, P < 0.05 to 0.01 ) . The distribution of extracellular matrix and types Ⅰ and Ⅲ collagen in lung tissue were obviously increased in bleomycin group as compared with that in control group, but decreased in different degrees in fluvastatin-treated groups.CONCLUSION: Fluvastatin can significantly inhibit the proliferation of rat lung fibroblasts in vitro, suggesting that it may be an effective drug for pulmonary fibrosis. Treatment at earlier stage is more effective than at advanced stage.