[Anterior cervical hybrid surgical treatment for multilevel cervical spondylotic myelopathy].

OBJECTIVE: To evaluate the clinical results of anterior cervical discectomy and reconstruction with a self-locking cage and internal fixation with short segmental plate for multilevel cervical spondylotic myelopathy. METHODS: From January 2012 to June 2015, a total of 106 patients received anterior cervical discectomy and reconstruction with a self-locking cage and internal fixation with short segmental plate were followed up. There were 71 males and 35 females, aged from 42 to 74 years old with an average of(55.4±5.1) years. Three segments were involved in 82 cases and four segments in 24 cases. Operation time, blood loss, postoperative drainage, and hospitalization time were recorded. Visual analogue scale(VAS) and Japanese Orthopaedic Association Score (JOA) were analyzed before and after operation(including 5 days, 3, 6, 12 months after operation and final follow-up), and the JOA improvement rate was analyzed. The cervical lordosis and ROM were measured before and after operation(including the follow-up point above) by X-rays. The postoperative complications were recorded and analyzed as well. RESULTS: All the operations were successful. The average operative time was (126.2±25.1) min, and the amount of blood loss was (82.1±26.3) ml. All the patients were followed up from 12 to 48 months with an average of (30.4±10.5) months. The VAS score of neck pain and JOA score was significantly better from 6.11±1.54 and 9.22±2.42 preoperatively to 2.14±0.51 and 12.46±1.42 at 5 days post-operation, respectively(P<0.05). The improvement rate of JOA was (56.7±21.6)%, there was no statistically significant difference of VAS, JOA scores and the improvement rate of JOA at each time after operation (P>0.05). Postoperative cervical lordosis at 3 months was significantly improved from preoperative (11.5±6.8)° to (19.6±8.9)°(P<0.05), and it can keep satisfactory stability until final follow-up(P>0.05). Postoperative ROM at 3 months was significantly decreased from the preoperative (37.6±10.4)° to (18.2±5.9)°(P<0.05), but there was no significant change in the process of follow-up (P>0.05). All the complications such as dysphagia (19 cases), axial neck pain(6 cases), cerebral fluid leakage(3 cases), and hoarseness(2 cases), got better after conservative treatment. Three cases had intervertebral space non-fusion until final follow-up(without clinical symptom), but no loosening, breakage, or displacement of internal fixation were found. CONCLUSIONS: Anterior cervical discectomy, reconstruction with a self-locking cage and internal fixation with short segmental plate which can reduce intraoperative injury, restore cervical lordosis, improve neurological function and lower postoperative complications, it is an alternative treatment for multilevel cervical spondylotic myelopathy.

Peripheral nerve injury decreases the expression of metabolic glutamate receptor 7 in dorsal root ganglion neurons.

Group II and III metabolic glutamate receptors (mGluRs) are responsible for the glutamate-mediated postsynaptic excitation of neurons. Previous pharmacological evidences show that activation of mGluR7 could inhibit nociceptive reception. However, the distribution and expression patterns of mGluR7 after peripheral injury remain unclear. Herein we found that mGluR7 was expressed in the rat peptidergic dorsal root ganglion (DRG) neurons and large neurons, but rarely in isolectin B4 positive neurons. Sciatic nerve ligation experiment showed that mGluR7 was anterogradely transported from cell body to the peripheral site. Furthermore, after peripheral nerve injury, mGluR7 expression was down-regulated in both peptidergic and large DRG neurons. Our work suggests that mGluR7 might be involved in the regulation of pathological pain after peripheral nerve injury.

[Effects of Bushen Zhuangjin Decoction containing serum on the apoptosis of chondrocytes induced by mechanics stimulus].

OBJECTIVE: To study the effects of Bushen Zhuangjin Decoction (BZD) containing serum on the apoptosis of chondrocytes induced by mechanics stimulus. METHODS: The BZD containing serum was extracted. The chondrocyte nutritive media was divided into 3 groups, i.e., the common nutritive medium group, the blank rabbit serum medium group, and the BZD nutritive medium group. The apoptosis of chondrocytes was induced by continuing mechanics stimulus in 24 h. Then the chondrocytes were collected. The apoptosis rate of chondrocytes was determined by flow cytometry. The contents of interleukin 1beta (IL-1beta) and nitric oxide (NO) in the corresponding media were determined. RESULTS: The apoptosis of chondrocytes in the BZD nutritive medium group (19.55 +/- 7.98)% was lower than that of the common nutritive medium group (39.32 +/- 13.45)% and the blank rabbit serum medium group (37.87 +/- 9.67)%, showing statistical difference (P < 0.05). The contents of IL-1beta and NO were also lower in the BZD nutritive medium group with statistical difference when compared with those of the other two groups (P < 0.05). CONCLUSION: BZD containing serum could protect mechanics stimulus induced apoptosis of chondrocytes.

5-Azacytidine facilitates osteogenic gene expression and differentiation of mesenchymal stem cells by alteration in DNA methylation.

Mesenchymal stem cells (MSCs) are considered to be one of the most promising therapeutic cell sources as they encompass a plasticity of multiple cell lineages. The challenge in using these cells lies in developing well-defined protocols for directing cellular differentiation to generate a desired lineage. In this study, we investigated the effect of 5-azacytidine, a DNA demethylating agent, on osteogenic differentiation of MSCs. The cells were exposed to 5-azacytidine in culture medium for 24 h prior to osteogenic induction. Osteogenic differentiation was determined by several the appearance of a number of osteogenesis characteristics, including gene expression, ALP activity, and calcium mineralization. Pretreatment of MSCs with 5-azacytidine significantly facilitated osteogenic differentiation and was accompanied by hypomethylation of genomic DNA and increased osteogenic gene expression. Taking dlx5 as a representative, methylation alterations of the "CpG island shore" in the promoter caused by 5-azacytidine appeared to contribute to osteogenic differentiation.

The effect of extracellular calcium and inorganic phosphate on the growth and osteogenic differentiation of mesenchymal stem cells in vitro: implication for bone tissue engineering.

The aim of this study is to demonstrate the effect of extracellular calcium ion (Ca2+) and inorganic phosphate (Pi) concentrations on the growth and differentiation of bone-marrow-derived mesenchymal stem cells (MSCs), which is essential to understand the interaction between calcium phosphate ceramic (CPC) scaffolds and seeded cells during the construction of tissue-engineered bones. MSCs were separated from rabbits and cultured in media with different concentrations of Ca2+ and Pi supplements. Their proliferation, apoptosis, mineralization and osteogenic differentiation were determined by the MTT assay, TUNEL assay, Vonkossa stain and RT-PCR examination. A two-way ANOVA calculation with comparisons of estimated marginal means by LSD was used for statistical analysis. Results showed that the optimal extracellular Ca2+ and Pi concentrations for the cells to proliferate and differentiate were 1.8 mM and 0.09 mM, respectively, which are the concentrations supplied in many commonly used culture media such as DMEM and alpha-MEM. Cell proliferation and differentiation decreased significantly with greater or lower concentrations of the Pi supplement. Greater Pi concentrations also led to significant cell apoptosis. Greater Ca2+ concentrations did not change cell proliferation but significantly inhibited cell differentiation. In addition, greater Ca2+ concentrations could significantly enhance cell mineralization. In conclusion, extracellular Ca2+ and Pi significantly influence the growth and osteogenic differentiation of MSCs. It is important to take the cellular effect of Ca2+ and Pi into consideration when designing or constructing scaffolds for bone tissue engineering with CPC.

Different effects of nanophase and conventional hydroxyapatite thin films on attachment, proliferation and osteogenic differentiation of bone marrow derived mesenchymal stem cells.

UNLABELLED: It is suggested that nanophase hydroxyapatite (nHAP) might have advantages over conventional hydroxyapatite (cHAP) as a biomaterial for bone regeneration. To be a satisfactory candidate for bone tissue engineering, it is important to support the growth and differentiation of bone marrow-derived mesenchymal stem cells (BMSCs). The purpose of this study is to determine whether nHAP as cell growth substrata could give better support for attachment, proliferation and osteogenic differentiation of BMSCs than cHAP. MATERIALS AND METHODS: nHAP and cHAP films were prepared as the substrata for the cell growth. BMSCs obtained from rabbit were seeded on the films. Attachment, proliferation and osteogenic differentiation of BMSCs on the two kinds of films were evaluated. RESULTS: Cell attachment ratio on nHAP films was significantly higher than that on cHAP films. Doubling time on nHAP films was significantly shorter than that on cHAP films. Amount of total proteins detected from cells cultured on nHAP films was significantly higher than that on cHAP films. However, alkaline phosphatase activity and osteocalcin content of the two groups showed no significant difference. CONCLUSIONS: nHAP films favored cell attachment and proliferation but not osteogenic differentiation of BMSCs compared with cHAP films.

In vitro differentiation of embryonic stem cells into hepatocytes induced by fibroblast growth factors and bone morphological protein-4.

The feasibility of transforming embryonic endoderm into different cell types is tightly controlled by mesodermal and septum transversumal signalings during early embryonic development. Here, an induction protocol tracing embryonic liver development was designed, in which, three growth factors, acid fibroblast growth factor, basic fibroblast growth factor and bone morphological protein-4 that secreted from pre-cardiac mesoderm and septum transversum mesenchyme, respectively, were employed to investigate their specific potency of modulating the mature hepatocyte proportion during the differentiation process. Results showed that hepatic differentiation took place spontaneously at a low level, however, supplements of the three growth factors gave rise to a significant up-regulation of mature hepatocytes. Bone morphological protein-4 highlighted the differentiation ratio to 40-55%, showing the most effective promotion, and also exhibited a synergistic effect with the other two fibroblast factors, whereas no similar phenomenon was observed between the other two factors, which was reported for the first time. Our study not only provides a high-performance system of embryonic stem cells differentiating into hepatocytes, which would supply a sufficient hepatic population for related studies, but also make it clear of the inductive effects of three important growth factors, which could support for further investigation on the mechanisms of mesodermal and septumal derived signalings that regulate hepatic differentiation.