Objective To observe the tumorigenicity of High Five insect cell line in Balb/c nude mice,and make sure the safety of the cells when used in vaccine production.Methods Balb/c nude mice were randomly divided into 5 groups:the basic cell bank of High Five group,the highest limited passages of High Five group,HEp-2 cell group as positive control,CEF cell group as negative control,and blank control.Except of the blank control,cell suspension was injected subcutaneously into the nude mice in the different groups,respectively.At 3 and 12 weeks after injection,anatomical observation and histopathologic examination were performed to detect the tumor formation.Results At 3 and 12 weeks after injection,the tumorigenicity study results showed that no tumor developed at the transplantation site in the blank control group,negative group,and High Five groups.Histopathological examinations also showed no abnormality in these groups.Otherwise,squamous cell carcinoma was developed in the positive group at 3 weeks after injection.Conclusions High Five cells of basic cell bank and highest limited passages are not tumorigenic,and can be used in vaccine production safely.

Occipitocervical fusion (OCF) is used to treat the instability of the cranio-cervical junction due to various reasons (such as trauma, rheumatoid arthritis, infection, tumor, congenital malformations and degeneration). A satisfactory fusion rate can be obtained and the stability of the occipital neck can be reconstructed by OCF. Dysphagia is one of the most common complications after OCF, which seriously affects the quality of life of patients after surgery. This article mainly focuses on the evaluation and prediction methods of dysphagia after OCF, and summarizes related research in the past 16 years, and provides guidance and direction for how to predict the occurrence of dysphagia during OCF and the evaluation of postoperative dysphagia. The evaluation of dysphagia is mainly conducted using the Bazaz dysphagia score, swallowing quality of life scale (SWAL-QOL) and eating assessment tool-10 (EAT-10) score. However, the clinical prediction of dysphagia is mainly based on the changes of cervical curvature parameters (O-C 2 angle, O-EA angle, Oc-Ax angle, PI angle). At present, there are many methods for clinical evaluation and prediction of dysphagia, but the best evaluation method is still uncertain. We reviews the evaluation and prediction methods of postoperative dysphagia of OCF, showing that the Bazaz dysphagia score, SWAL-QOL score and EAT-10 score scale are suitable for evaluating postoperative dysphagia of OCF. During OCF operation, adjustment of O-C 2 Angle >-5°, O-EA Angle >100°, Oc-Ax Angle >65°, and increase of postoperative PI Angle from preoperative PI Angle (that is, dPI Angle) ≥0° can reduce the probability of dysphagia to a certain extent.