ABSTRACT
<p><b>OBJECTIVE</b>To investigate the effect of hypoxia on the proliferation and expressions of hypoxia-inducible factor-1α (HIF-1α), vascular endothelial growth factor (VEGF) and matrix metalloproteinase-9 (MMP-9) in keratinocytes obtained from oral lichen planus (OLP) lesions.</p><p><b>METHODS</b>Hypoxia environment was induced by a airtight incubator. Five groups were included, normoxia control group, hypoxia control group (12, 24, 36, 48 h). The effect of different treatment time of hypoxia on cellular proliferation was determined with cell counting kit-8 (CCK-8). The mRNA and protein expressions of HIF-1α, VEGF and MMP-9 were analyzed respectively by quantitative real-time polymerase chain reaction with SYBR Green I and Western blotting.</p><p><b>RESULTS</b>The growth activity of keratinocytes obtained from OLP lesions in the hypoxia groups (0.340±0.002, 0.415±0.006, 0.546±0.006) was reduced than that in control (0.431±0.001, 0.620±0.004, 1.022±0.005) (P < 0.01). The mRNA levels of VEGF (2.087±0.291, 3.189±0.573, 5.402±0.563) and MMP-9 (2.936±0.500, 4.083±0.300, 6.374±0.858) were elevated by hypoxia (P < 0.05). The protein levels of HIF- 1α (0.414±0.093, 0.751±0.056, 0.875±0.040), VEGF (0.393±0.046, 0.557±0.078, 0.767±0.045) and MMP-9 (0.250±0.053, 0.384±0.038, 0.611±0.092) were all remarkably elevated by hypoxia (P < 0.05). However, hypoxia had no effect on HIF-1α mRNA expression. The mRNA expression of HIF-1α after hypoxia exposure for 36 h (1.412±0.094) and 48 h (1.417±0.446) was higher than that of control group, however, there was no significant difference. A positive correlation was noted between HIF-1α and VEGF in protein level (r = 0.905, P = 0.000), and the same correlation found between HIF-1α and MMP-9 (r = 0.881, P = 0.000).</p><p><b>CONCLUSIONS</b>Hypoxia conditions may inhibit the proliferation of keratinocytes obtained from OLP lesions. Hypoxia conditions can promote the protein expressions of HIF-1α and both the mRNA and protein expression of VEGF and MMP-9 in keratinocytes obtained from OLP lesions exposed to hypoxia. The relative high expression of HIF-1α may be involved in multiple aspects of OLP progression through the regulation of its downstream target genes.</p>
Subject(s)
Humans , Blotting, Western , Cell Hypoxia , Physiology , Cell Proliferation , Hypoxia-Inducible Factor 1, alpha Subunit , Metabolism , Keratinocytes , Metabolism , Lichen Planus, Oral , Pathology , Matrix Metalloproteinase 9 , Metabolism , RNA, Messenger , Metabolism , Real-Time Polymerase Chain Reaction , Vascular Endothelial Growth Factor A , MetabolismABSTRACT
The quality of doctoral degree conferring depends on the quality of doctoral dissertation.Based on the quality evaluation of doctoral dissertation in medical School of Shanghai Jiaotong University in 2005,the author points out the problems existing in doctoral dissertation nowadays and makes some explorations on how to improve the quality of doctoral degree conferring.
ABSTRACT
The training of residents constitutes the primary work of Graduate Medical Education.Reviewing the historical development of the training of residents,we find that it has experienced four stages and trended to establish the medical specialist training system.
ABSTRACT
Based on the relevant theories and methods concerning the evaluation of higher education, authors used student questionnaires to evaluate the teaching quality of the 23 courses in the postgraduate curriculum, including basic theoretic courses, specialty-related basic courses and courses of methodology for scientific research. The methods used involve 'evaluation by students' and the integrated evaluation of both the quantitative and qualitative aspects of various factors. The easy-to-use student's questionnaires make it possible to find, with respect to students, teachers, and courses, many factors affecting the teaching quality, and at the same time, to provide the close following-up of the process of postgraduate training.