ABSTRACT
BACKGROUND: Growth factors and other biological methods have become very popular in the repair of degenerative interevrtebral disc. Insulin-like growth factor-1 (IGF-1) can promote the proliferation of nucleus pulposus cells, and synthesis of functional extracellular matrix, but the mechanisms remain unclear.OBJECTIVE: To investigate the effect of IGF-Ⅰ on the expressions of aggrecan and collagen type Ⅱ in nucleus pulposus cells, and to explore its signal transduction mechanism.METHODS: The human nucleus pulposus cells were isolated and cultured. Passage 3 nucleus pulposus cells were induced in different concentrations of IGF-1 (0, 20, 50, 100 and 200 μg/L), respectively. The expressions of aggrecan and collagen type Ⅱ were detected by reverse transcription PCR and western blot assay. Western blot assay was adopted to observe the effect of 100 μg/L IGF-1 on the activation of PI3K/Akt signaling pathway in nucleus pulposus cells,and the expression of aggrecan and collagen type Ⅱ was detected after the inhibition of PI3K/Akt pathway by LY294002.RESULTS AND CONCLUSION: With the increase of IGF concentration, the expression levels of aggrecan and collagen type Ⅱ were increased gradually. 100 μg/L IGF-1 could significantly promote the expressions of p-PI3K and p-Akt (P <0.01), while LY294002 reversed this effcet (P < 0.01). 100 μg/L IGF-1 significantly upregulated the expression levels of aggrecan and collagen type Ⅱ in nucleus pulposus cells (P < 0.01); in contrast, LY294002 significantly downregulated the expression levels of aggrecan and collagen type Ⅱ promoted by IGF-1(P < 0.01). These results indicate that IGF-1 can promote the expression levels of aggrecan and collagen type Ⅱ in nucleus pulposus cells via the PI3K/Akt signaling pathway.
ABSTRACT
Objective To investigate the clinic efficacy of proximal humeral internal locking system(PHILOS) in the treatment of Neer Ⅱ and Ⅲ proximal humeral fractures.Methods From January 2013 to December 2015,a total of 47 patients with Neer Ⅱ and Ⅲ proximal humeral fractures was treated with PHILOS fixation in our hospital.The operative time,blood loss in operation,hospital stay,complications,Constant scores and radiography films were retrospectively analyzed.Results All 47 patients were followed up for an average of (19.2 ±9.6) month.The average operative time,the level of average intraoperative blood loss,the mean hospitalization time and the complication rate were(95.6 ±43.1) min,(108 ± 41.6) mL,(11.3 ±3.2) d and 14.7 ％ respectively.The Constant score was improved from(21.74 ± 8.24) preoperatively to(82.83 ± 7.21) at the last follow-up,and the difference was statistically significant(t=-36.57,P＜0.01).Conclusion Fixation with PHILOS is a safe and effective treatment for patients with Neer Ⅱ and Ⅲ proximal humeral fractures.