ObjectiveTo observe and compare the cytological and biological differences between human normal and degenerated nucleus pulposus (NP), and to investigate the repair effect of insulin-like growth factor 1 (IFG-1) and platelet derived growth factor (PDGF) on human degenerated NP.MethodsHuman degenerative and normal NP tissues were obtained from operative patients, a portion of which were processed into tissue sections and HE staining was performed to observe the morphological changes of nucleus pulposus cells (NPCs) before and after degeneration of NP. Immunohistochemistry staining was used to determine the expression levels of collagen type Ⅰ, collagen type Ⅱ, B-cell lymphoma 2 (Bcl-2), Bcl-2 associated X (Bax) proteins. Another portion of tissues were isolated and cultured and NPCs morphology was observed under inverted microscope. Western blot analysis was used to detect collagen type Ⅱ protein expression. Then, the gene transfection experiments were launched, including 4 groups, with group A designed as degenerated NPCs only, and groups B, C, and D of degenerated NPCs transfected with IGF-1 gene lentiviral particles, PDGF gene lentiviral particles, and lentiviral particles carrying IGF-1 and PDGF double genes, respectively. At 21 days after transfection, the cell morphology of each group was observed under inverted microscope, the positive rates of IGF-1 and PDGF of each group were measured by flow cytometry, and the expression of collagen type Ⅱ protein was detected by using immunohistochemistry staining and Western blot.ResultsHE staining showed that there were a large number of notochordal cells and a small number of chondrocytes in the central NP tissue of normal group, while the NPCs in degeneration group were significantly reduced, and a large proportion of fibrocartilage tissues were found in NP tissue. Immunohistochemistry staining showed that the percentages of collagen type Ⅰ and Bax protein-positive cells in degeneration group were significantly higher than those of normal group, while the percentages of collagen type Ⅱ and Bcl-2 protein-positive cells were significantly lower than those of normal group (P<0.05). Western blot showed that the relative expression level of collagen type Ⅱ protein in degeneration group was significantly lower than that in normal group (t=65.493, P=0.000). At 21 days after gene transfection, compared with group A, the cell viability of groups B, C, and D increased and the morphology became more regular. Flow cytometry showed that the percentages of IGF-1-positive cells in groups B and D were significantly higher than that in group A, and the percentages of PDGF-positive cells in groups C and D were significantly higher than that in group A (P<0.05). Immunohistochemistry staining showed that the positive stainings of collagen type Ⅱ in groups A, B, C, and D was (±), (+), (+), and (++), respectively. Western blot showed that the relative expression of collagen type Ⅱ protein in groups A, B, C, and D increased by degrees, and the differences between groups were significant (P<0.05).ConclusionBoth IGF-1 and PDGF can reverse the degeneration of intervertebral discs NPCs and they have synergistic effects, providing experimental basis for its application in clinical treatment approaches for degenerative disc disease.
Objective To assess the effectiveness of locking compress plate and extra cortical bone bridge fixation for treating atrophic humeral nonunion. Methods Seventeen patients with atrophic humeral nonuninon were treated with locking compress plate and extra cortical bone bridge fixation between November 2006 and June 2015. Of 17 cases, 11 were male, 6 were female, aged 24-63 years (mean, 38.2 years). Fracture located at the left side in 9 cases and at the right side in 8 cases. The mechanism of injury was traffic accident in 13 cases, falling from height in 3 cases, and heavy pound injury in 1 case. The patients underwent surgery for 1 time in 7 cases, for 2 times in 5 cases, for 3 times in 4 cases, and for 4 times in 1 case. The time from fracture to hospitalization was 10-76 months (mean, 22.6 months). The shoulder function was evaluated by Neer score, and elbow function by Mayo score. Results All incisions healed by first intention. Two cases had transient radial nerve symptoms of numbness. All patients were followed up 27.3 months on average (range, 15-60 months). Radiographic examination showed signs of bone remodeling at 6-8 weeks after operation, and formation of extra cortical bone bridge. All of them achieved bone union within 10 to 41 weeks (mean, 17.6 weeks). At last follow-up, the average Neer score was 83.36 (range, 72-96); and the shoulder function was excellent in 10 cases, good in 5, and fair in 2 with an excellent and good rate of 88.24%. And the average Mayo score was 86.52 (range, 68-100); and the elbow function was excellent in 11 cases, good in 3, and fair in 3 with an excellent and good rate of 82.35%. Conclusion The bone bridging could effectively form by extra cortical grafting technique. Atrophic humeral nonunions can be successfully treated with locking compress plate and extra cortical bone bridge fixation.