The spinal cord, encompassed by the dura mater, arachnoid membrane, pia mater, dentate ligament, and cerebrospinal fluid, consists of both gray and white matter. This study delves into the biomechanical properties of the spinal cord and its adjacent structures, revealing its nature as a nonlinear viscoelastic medium. Notably, both gray and white matter exhibit hyperelastic characteristics, displaying distinct mechanical responses during uniaxial tensile and mechanical compression experiments. Furthermore, it is noteworthy that the human spinal cord does not maintain uniform length, while the dura mater exhibits pronounced anisotropy, with its elastic modulus gradually decreasing from the cervical to the lumbar region. While research on the biomechanical behavior of the arachnoid membrane is limited, its potential to enhance predictive accuracy in spinal finite element models is evident. Unfortunately, there is a lack of documented studies exploring the biomechanics of the human pia mater. Crucially, the spinal cord is immersed in cerebrospinal fluid, which acts as a cushion against spinal cord vibrations. Therefore, the significance of cerebrospinal fluid should not be underestimated in examining the biomechanical dynamics of the spinal cord, as changes in cerebrospinal fluid pressure correspondingly affect spinal cord stress levels. Additionally, the strength of the dentate ligament decreases progressively from superior to inferior regions. Due to the inherent softness of spinal cord tissue, it often undergoes complex mechanical alterations such as stretching, compression, and torsion when subjected to injury. Various measurement techniques, including magnetic resonance elastography (MRE), atomic force microscopy, microindentation, and myelography, are employed for spinal cord assessment. MRE, in particular, offers distinct advantages in scrutinizing spinal cord morphology. Accurately quantifying the mechanical parameters of spinal cord deformation injuries remains a challenge. Advanced imaging technologies are employed to monitor the dynamic pathological transformations of the spinal cord, providing valuable insights for clinical prevention and treatment strategies. Finite element analysis plays a pivotal role in the study of spinal cord injuries. However, existing modeling methodologies often oversimplify the spinal cord, portraying it as a homogenous material. Further experimental validation is required to confirm its accuracy. An exhaustive exploration of spinal cord biomechanics and measurement techniques is essential to gain a deeper understanding of the mechanisms underlying spinal cord injuries. This knowledge can serve as crucial theoretical guidance and support for the treatment and prevention of such injuries.

BACKGROUND: Pathophysiological mechanism of local microenvironment is complex after central nerve injury; especially,both inflammatory reaction at an acute phase and formation of secondary glial scar have tremendous effects on effective regeneration of axon, regeneration and arrangement of local nerve cells, proliferation and migration of local stem cells;therefore, it becomes a basic reason for blocking nerve repair in an early period. Thus, how to effectively resist inflammatory factors in injured region at an acute phase and how to optimize microenvironment of neural regeneration are the most important strategies for repairing spinal cord injury in recent years.OBJECTIVE: To design, establish and screen the best expression of interleukin-6 receptor (IL-6R) α to inhibit shRNA adenovirus expression vector by using spinal cord injury models.DESIGN: Duplicative measurement study.SETTING: Department of Spine Surgery, the Second People's Hospital of Shenzhen.MATERIALS: A total of 40 healthy Wistar rats, either gender, 8-10 weeks old, were selected in this study. Rabbit-anti-rat glial fibrillary acidic protein (GFAP) antibody Ⅰ was provided by Santa Cruz Compan; siRNA eukaryon expression plasmid pGenesil (cohtaining green fluorescent expression system) was provided by Wuhan Jingsai Bioengineering Company.METHODS: The experiment was carried out in ImmuneOpening Laboratory, Basic Medical Faulty, Tongji Medical College, Huazhong University of Science and Technology, and Medica Laboratory Center, the Second People's Hospital of Shenzhen in November 2006. Three pairs of shRNA template which composed of 19 bp reverse repeated motif of IL-6 receptor (IL-6R) α target sequence with 9 bp spacer were designed and synthesized, then the recombinant adenovirus expression vectors with green fluorescence protein were constructed in vitro respectively. The acute spinal cord injury models were completed, and the adenovirus recombinants were regionally injected post 12 hours after spinal cord injury;in addition, the inhibitory effect of RNA interference (RNAi) on expression of IL-6R in local region after spinal cord injury were detected by using real-time fluorescence quantitative reverse transcription polymerase chain reaction (RT-PCR) and Western blot so as to screen adenovirus expression vector which had the best inhibitory effect on expression of IL-6R.MAIN OUTCOME MEASURES: Inhibitory effect of RNAi on expressions of IL-6R RNA and protein in local region after spinal cord injury.RESULTS: Sequence analysis showed that IL-6R-shRNA recombinant adenovirus expression vector was successfully constructed, and optimal IL-6R-shRNA recombinant adenovirus expression vector was screened by using real-time fluorescence quantitative RT-PCR and Western blot. The IL-6R expressions were 49% and 56% at the levels of mRNA and protein, respectively.CONCLUSION: The IL-6R--shRNA recombinant adenovirus expression vector is successfully constructed and screened.The gene expression of IL-6R can be highly inhibited after acute spinal cord injury.

Objective To investigate the relationship between a mutation in the platelet-activating factor (PAF) acetylhydrolase gene (Arg92→His) and psoriasis. Methods Genomic DNA was analyzed in 47 patients with psoriasis and 52 healthy controls via polymerase chain reaction and restriction fragment length polymorphism. Results The frequency of the mutation in the PAF acetylhydrolase gene (Arg92→His) was significantly higher in patients with psoriasis than that in the controls (P

0.1). Plasma PAF-AH activity in the patients with psoriasis was significantly lower than that in the healthy controls(P

AIM:To study the inhibitory effect and its mechanisms of the extract of Oratosquilla oratoria (EOS) on the activity of telomerase in human nasopharyngeal carcinoma cell line CNE-2Z. METHODS:MTT assay was used to determine the effect of different doses of EOS on the proliferation of CNE -2Z cells. The activity of telomerase was analyzed by TRAP-ELISA. The mRNA expression of hTERT was determined by RT-PCR,and the protein expression of c-Myc was detected by Western blotting. RESULTS:EOS inhibited the proliferation of CNE-2Z cells in a dose-dependent manner (P