ABSTRACT
BACKGROUND: Highway accidents increase year by year, and the most vulnerable area is the neck. Finite element analysis can be used to study the mechanical mechanism of cervical injury. Most of researches focus on the optimization of the model and low-speed collision conditions, but the association of neck injury with cervical tension stress is little reported. OBJECTIVE: To explore the mechanical mechanism of neck injuries caused by traffic accidents, and to compare the von Mises and axial stress of the cervical vertebrae. METHODS: A cervical spine model including cervical vertebrae, intervertebral disc, ligament, muscle, facet joint was set up. The model was validated based on the experimental data of the former impact volunteers. The dynamic response of the cervical vertebrae was achieved using the finite element method (80, 120, and 160 km/h). RESULTS AND CONCLUSION: (1) The established upper cervical model had a high biosimulation, which could be used in studies on the cervical injury and each part injury caused by traffic accidents. (2) Under high-speed post-impact condition, the cervical injury became severe with speed increasing, especially C4level. (3) The axial stress was more available to assess the injury of cancellous bone than von Mises. (4) After high-speed post-impact, the vertebrae diaplaced, especially at 120 km/h, thereby causing articular separation and fracture, further inducing nerve root injury.
ABSTRACT
Purpose To detect the expression of autophagy-related genes Beclin1 and microtubule-associated protein1 light chain3 (LC3) in ovarian serous carcinoma (OSC) and to analyze the correlations with clinical pathological characteristics and prognosis of patients with OSC.Methods Immunohistochemical staining of MaxVision two-step was performed to detect the expression of Beclin1 and LC3 in the samples from 63 OSC patients and 20 with benign ovarian serous cystadenomas.The relation between Beclin1 and LC3 with the factors influencing the prognosis of OSC was investgated.The expression levels of mRNA and proteins in 10 fresh OSC samples and their corresponding adjacent noncancerous tissues were examined by RT-PCR and Western blot.Results The positive percentage of Beclin1 and LC3 protein in the tissues of OSC was 36.51％ and 33.33％,which was significantly lower than that of 65.00％ and 60.00％ in serous cystadenomas (P =0.025,P =0.034).The expression of Beclin1 in OSC was significantly correlated with clinical FIGO stage and pathological grade (P =0.001,P =0.001),but not associated with age,site,tumor size and lymph node metastasis (P ＞ 0.05).The expression of LC3 protein in OSC was significantly with clinical FIGO stage and lymph node metastasis (P =0.013,P =0.041),but not associated with age,site,tumor size and pathological grade (P ＞ 0.05).There was a positive correlation between Beclin1 and LC3 in OSC (rs =0.373,P =0.03).The levels of Beclin1 and LC3 mRNA (0.581-±0.091,0.650 ±0.090) in 10 fresh OSC were significantly lower than in their adjacent noncancerous tissues (t=8.083,t =6.614,P =0.016,P =0.022).The levels of Beclin1 and LC3 protein in 10 fresh OSCs were significantly lower than in their adjacent noncancerous tissues (P ＜ 0.05).Kaplan-Meier survival analyses revealed that the expression of Beclin1 and LC3 were associated with the patients prognosis (P =0.028 3,P =0.018 5).Conclusion Expression of Beclin1 and LC3 protein is down-regulated in the tissues of OSC which lead to decrease of function of autophagy.The decrease of Beclin1 and LC3 may be associated with the development and prognosis of OSC.
ABSTRACT
Objective To investigate effects of 3D co-culture of human keratinocytes (HKC) and human fibroblasts (HFB) under pressure on cell proliferation and collagen synthesis. Methods The HKC and HFB were planted on chitosan-gelatin scaffolds, respectively, for 2 d. The HKC-chitosan-gelatin complex (3D HKC) was cultured at air-liquid interface for 1 d to induce differentiation, and then co-cultured with the HFB-chitosan-gelatin complex (3D HFB) for 12 h. 3.4 kPa pressure was applied on the co-culture group for 24 h. The group of single culture with pressure, the group of single culture without pressure and the group of co-culture without pressure were used as control. HE staining was used to observe distribution and growth of HKC and HFB on chitosan-gelatin scaffolds. MTT method was used to test proliferation of HKC and HFB. Hydroxyproline kit was used to observe collagen concentration of the supernatant fluids. Results HE staining showed that HKC and HFB could grow confluently on chitosan-gelatin scaffolds；3.4 kPa pressure or co-culture both could promote the HKC proliferation and collagen synthesis, while restrain the HFB proliferation and collagen synthesis. Conclusions Pressure and co-culture play an important role in HKC and HFB proliferation and collagen synthesis. This research finding provides some reference for exploring the therapeutic mechanism of hyperplastic scar from clinical operation of resecting scar by transplanting tissue-engineered skin to the wound and then combined with pressure treatment.