Although application of intraoperative computer navigation technique had been integrated into placement of pedicle screws (PSs) in thoracic fusion for years, its security and practicability remain controversial. The aim of this study is to evaluate the accuracy, the operative time consumption, the amount of intraoperative blood loss, time of pedicle insertion and the incidence of complications of thoracic pedicle screw placement in patients with thoracic diseases such as scoliosis and kyphosis. Pubmed, Web of Knowledge, and Google scholar were searched to identify comparative studies of thoracic pedicle screw placement between intraoperative computer navigation and fluoroscopy-guided navigation. Outcomes of malposition rate, operative time consumption, insertion time, intraoperative blood loss, and the incidence of complications are evaluated. Fourteen articles including 1723 patients and 9019 PSs were identified matching inclusion criteria. The malposition rate was lower (RR: 0.33, 95 % CI: 0.28-0.38, P < 0.01) in computer navigation group than that in fluoroscopy-guided navigation group; the operative time was significantly longer [weighted mean difference (WMD) = 23.66, 95 % CI: 14.74-32.57, P < 0.01] in computer navigation group than that in fluoroscopy-guided navigation group. The time of insertion was shorter (WMD = -1.88, 95 % CI: -2.25- -1.52, P < 0.01) in computer navigation group than that in fluoroscopy-guided navigation group. The incidence of complications was lower (RR = 0. 23, 95 % CI: 0.12-0.46, P < 0.01) in computer navigation group than that in the other group. The intraoperative blood loss was fewer (WMD = -167.49, 95 % CI: -266.39- -68.58, P < 0.01) in computer navigation group than that in the other. In conclusion, the meta-analysis of thoracic pedicle screw placement studies clearly demonstrated lower malposition rate, less intraoperative blood loss, and fewer complications when using computer navigation. This result provides strong evidence that computer technology could be safer and more reliable than fluoroscopy-guided navigation.
The present study aimed to investigate the role of periostin (POSTN) and high melatonin concentrations in the apoptosis of hFOB 1.19 human normal fetal osteoblastic cells. hFOB 1.19 human osteoblastic cells were stably cultured and treated in different concentrations of melatonin for different durations of action. Apoptosis was assessed quantitatively using flow cytometric analysis. The results of western blot analysis demonstrated that the treatment of cells with different concentrations of melatonin for different durations of action revealed a positive association between melatonin and the expression levels of glucose‑regulated protein (GRP)78, GRP94, phosphorylated (p‑) eukaryotic initiation factor 2α (eIF2α), activating transcription factor (ATF)4, CCAAT/enhanced binding protein homologous protein (CHOP), cleaved caspase‑3, p‑c‑Jun N‑terminal kinase (JNK) and POSTN. When POSTN was inhibited, the levels of p‑JNK, CHOP, p‑eIF2α, ATF4 and cleaved caspase‑3 were significantly increased, whereas other proteins associated with the endoplasmic reticulum stress (ERS) pathways, including ATF6 and X‑box binding protein 1 (XBP1), were not significantly altered. Reverse transcription‑quantitative polymerase chain reaction analysis was also performed to assess the relative mRNA levels of ATF4, ATF6 and XBP1. The results of the present study are the first, to the best of our knowledge, to demonstrate that melatonin induced apoptosis in hFOB 1.19 human osteoblastic cells by activating the ERS‑associated eIF2α‑ATF4 pathway and subsequently triggered the cascade effects of CHOP, caspase‑3 and JNK. POSTN may function as a protective factor for osteoblasts during this process by inhibiting the eIF2α‑ATF4 pathway.
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