Objective To investigate the expression of aquaporin (AQP) 1, AQP4, inward rectifying potassium channel 4.1 (Kir4.1) and cytoskeleton features of rat spinal cord astrocytes after cytochalasin D (CytD) intervention. Methods Spinal cord astrocytes isolated from 2~3-day-old rats were cultured till confluency. MTT was used to assess survival rate of astrocytes 2 h, 12 h and 24 h after co-cultured with 0.05 μg/ml, 0.10 μg/ml, 0.20 μg/ml, 0.40 μg/ml, 0.80 μg/ml and 1.00 μg/ml of CytD, respectively. Confocal microscopy was used to observe cytoskeleton features of astrocytes 2 h after co-cultured with 0.05 μg/ml, 0.10 μg/ml, 0.20 μg/ml, 0.40 μg/ml of CytD. The expression of AQP1, AQP4, Kir4.1 mRNA were determined with real-time PCR 2 h after co-cultured with 0.05 μg/ml, 0.10 μg/ml, 0.20 μg/ml, 0.40 μg/ml, 0.80 μg/ml and 1.00 μg/ml of CytD. Results The survival rate of rat spinal cord astrocytes reduced with the time of co-culture and concentration of CytD (P<0.05). The cytoskeleton of astrocytes was reconstructed. The expression of AQP1, AQP4 and Kir4.1 mRNA increased after co- cultured with 0.05~0.40 μg/ml of CytD. Conclusion The appropriate dosage of CytD may remodel the cytoskeleton and increase the mRNA expression of AQP1, AQP4 and Kir4.1 in spinal cord astrocytes of rats.

【Objective】 To study the clinical practice and early outcome of percutaneous full-endoscopic modified posterior lumbar interbody fusion（mPLIF）combined with pedicle screw fixation through paraspinal muscle clearance. 【Methods】 A retrospective study was conducted to analyze the clinical data of patients with lower lumbar spinal diseases treated from May 2019 to April 2020. All the enrolled patients received mPLIF combined with pedicle screw fixation through paraspinal muscle clearance. The follow-up period was more than 1 year； the general parameters included age， gender， duration of disease， diagnosis of disease， surgery segment， and postoperative hospitalization time. Operation parameters included operation time and blood loss. We obtained the clinical parameters such as visual analogue scale （VAS） score for back and lower extremity， Oswestry disability index （ODI） score， and Macnab satisfaction score at the last follow-up. We evaluated the imaging parameters including intervertebral disc height， segmental lordosis angle， lumbar lordosis angle， as well as fusion outcome of patients with single segmental lumbar disease. In addition， intraoperative and postoperative complications were recorded. 【Results】 Totally 18 patients met the inclusion criteria， among whom 8 were male and 10 were female， with the average age of （53.3±8.3） years old and the average duration of disease being （28.9±36.6） months. Among them 16 patients were diagnosed as lumbar degenerative disease and the other 2 had lumbar disc infection. One patient received L3-L4 and L4-L5 intervertebral fusion； the others had one-segmental fusion， among which 11 cases were L4-L5 and 6 cases were L5-S1. The average operation time was （207.8±31.7） min， and the average blood loss was （25.6±7.8） mL， and the mean postoperative hospitalization time was （6.56±2.30） days. VAS scores of back and lower extremities at postoperative 1 week， 6 months and the last follow-up were statistically significantly improved from the preoperative scores. ODI scores at postoperative 6 months and the last follow-up were also statistically significantly improved. The rate of excellent and good according to the Macnab criteria was 94.4%. For the 17 single-level fusion patients， intervertebral height was significantly higher postoperatively and at the last follow-up compared with that of the preoperative one （P<0.05）. Segmental lordosis angle was bigger postoperatively and at the last follow-up （P>0.05）， which was not statistically significant. Lumbar lordosis angle was significantly bigger postoperatively （P<0.05） and bigger at the last follow-up， but with no statistical significance （P>0.05）. The fusion rate at the last follow-up was 88.2%. The cage broke in the process of implantation in one patient. A cage retroposition occurred in one patient at the follow-up. 【Conclusion】 Percutaneous full-endoscopic modified posterior lumbar interbody fusion combined with pedicle screw fixation through bilateral paraspinal muscle clearance by one incision showed excellent clinical outcomes in treating many kinds of lower lumbar diseases. This operation should be an excellent option for lower lumbar fusion.