[Comparative study of two elastic fixation systems in single-segment lumbar disc herniation surgery for nucleus pulposus extraction].

OBJECTIVE: To investigate the clinical application of two elastic pedicle internal fixation systems in single-segment lumbar disc herniation fenestration. METHODS: A retrospective analysis of 64 patients with lumbar intervertebral disc herniation treated by surgery from June 2019 to March 2021. According to the different elastic fixation systems placed during the operation, the patients were divided into ordinary pedicle screw elastic rod link group (elastic rod group) and a special elastic pedicle screw rigid rod fixed connection group (elastic screw group). There were 33 cases in the elastic rod group, including 18 males and 15 females, aged from 30 to 69 years old with an average of(49.18±10.23) years old;and 31 cases in the elastic screw group, including 16 males and 15 females, aged from 32 to 68 with an average of (49.81±9.24) years old. The operation time, intraoperative blood loss, postoperative wound drainage, and postoperative landing time of the two groups were recorded separately. The visual analogue scale (VAS), Japanese Orthopaedic Association (JOA) score, and Oswestry Disability Index (ODI) were compared before and 3, 12 months after operation. The height of the adjacent vertebral space on the lateral DR film before and 12 months after the operation was measured. The clinical efficacy was evaluated by Macnab standard. RESULTS: All the patients successfully completed the operation, and were followed up. The operation time, intraoperative blood loss, postoperative wound drainage and postoperative landing time in the elastic rod group were(63.73±12.01) min, (89.55±16.07) ml, (81.67±16.00) ml, (3.45±0.75) d , while in the elastic nail group was (62.96±11.54) min, (88.35±17.14) ml, (82.29±15.40) ml, (3.29±0.78) d, the difference was not statistically significant. The symptoms of low back pain and lower extremity numbness were significantly improved in all patients after operation. There was no significant difference in VAS, JOA score and ODI between the two groups before and after surgery (P>0.05). At 12 months after operation, there was no significant difference in the height of the adjacent vertebral space between the upper adjacent vertebral body and the same segment before operation(P>0.05), and there was no significant difference between the groups before and after the operation. According to Macnab criteria, the elastic rod group was excellent in 30 cases, good in 2 cases, fair in 1 case, while the elastic nail group was excellent in 29 cases, good in 2 cases, fair in 0 cases, and there was no significant difference(Z=-0.42, P=0.68). CONCLUSION: In fenestrated nucleus pulposus extraction for lumbar disc herniation, the two elastic pedicle internal fixation systems are equally effective and can be used. The elastic screw internal fixation system has certain advantages when the distance between the two vertebral bodies is short, and the elastic rod cannot be placed or is difficult to be placed, and it is more widely used.

[Non-angiogenic functions of vascular endothelial growth factor].

Vascular endothelial growth factor (VEGF or VEGF-A), also named as vascular permeable factor (VPF), is a multi-functional bio-macromolecule belonging to the family of secreted glycoprotein growth factor. VEGF can induce a variety of cellular responses through two high-affinity tyrosine kinases, VEGFR1 and VEGFR2. VEGF plays a key role in the angiogenesis and development in the embryo phase, promoting the proliferation, migration, tube formation and survival of the vascular endothelial cells. In the adult phase, VEGF mainly participates in maintaining the vascular structure and regulating physiological and pathological angiogenesis. Clinical data showed that VEGF signaling inhibitors significantly induced the degeneration of the tumor vessels and reduced tumor size. Meanwhile, various side-effects also have been observed in some patients, indicating that the non-angiogenesis functions of VEGF should be greatly emphasized, especially when developing anti-cancer drugs. Several studies showed that VEGF plays essential roles in various adult organs, such as small intestine, pancreatic islets, thyroid, kidney and liver. When VEGF level in these organs is lower than normal, the complexity of capillary network will be partially degenerated. Apart from that, VEGF also promotes the bone marrow formation, tissue repair and regeneration, the maturation of ovarian, and participates in some pathological courses such as thrombosis, inflammation and ischemia. This review focuses on the non-angiogenesis functions of VEGF and briefly discusses the molecular mechanisms.

An Eight-CpG-based Methylation Classifier for Preoperative Discriminating Early and Advanced-Late Stage of Colorectal Cancer.

AIM: To develop and validate a CpG-based classifier for preoperative discrimination of early and advanced-late stage colorectal cancer (CRC). METHODS: We identified an epigenetic signature based on methylation status of multiple CpG sites (CpGs) from 372 subjects in The Cancer Genome Atlas (TCGA) CRC cohort, and an external cohort (GSE48684) with 64 subjects by LASSO regression algorithm. A classifier derived from the methylation signature was used to establish a multivariable logistic regression model to predict the advanced-late stage of CRC. A nomogram was further developed by incorporating the classifier and some independent clinical risk factors, and its performance was evaluated by discrimination and calibration analysis. The prognostic value of the classifier was determined by survival analysis. Furthermore, the diagnostic performance of several CpGs in the methylation signature was evaluated. RESULTS: The eight-CpG-based methylation signature discriminated early stage from advanced-late stage CRC, with a satisfactory AUC of more than 0.700 in both the training and validation sets. This methylation classifier was identified as an independent predictor for CRC staging. The nomogram showed favorable predictive power for preoperative staging, and the C-index reached 0.817 (95% CI: 0.753-0.881) and 0.817 (95% CI: 0.721-0.913) in another training set and validation set respectively, with good calibration. The patients stratified in the high-risk group by the methylation classifier had significantly worse survival outcome than those in the low-risk group. Combination diagnosis utilizing only four of the eight specific CpGs performed well, even in CRC patients with low CEA level or at early stage. CONCLUSIONS: Our classifier is a valuable predictive indicator that can supplement established methods for more accurate preoperative staging and also provides prognostic information for CRC patients. Besides, the combination of multiple CpGs has a high value in the diagnosis of CRC.