ABSTRACT
OBJECTIVE： To study the mechanism of analgesic effect of 8-O-acetyl-safalinoside （8-OaS） on chronic inflammatory pain model rats. METHODS ：Totally 30 male SD rats were divided into sham operation group （normal saline ）， model group （normal saline ），8-OaS low-dose ，medium-dose and high-dose groups （3，10，30 μg/kg），with 6 rats in each group. Except for sham operation group ，other groups were given planter injection of Freund ’s complete adjuvant to induce chronic inflammatory pain model. After successful modeling ，the rats in each group were given corresponding drugs intrathecally ，once a day，for 7 consecutive days. Then Von-Frey filaments were used to detect the planter pain threshold of the rats in each group ；the area under the planter pain threshold curve of each group and the half effective dose （ED50）of 8-OaS were calculated. Another 36 male SD rats were divided into sham operation group （normal saline ），model group （normal saline ）and 8-OaS group （dose of ED50），and the modeling method and administration route were the same as above. Immunofluorescence histochemical staining was used to observe the positive expression of ionized calcium binding adapter molecule 1（Iba-1）and signal molecule phosphorylated p38 mitogen-activated protein kinase （p-p38 MAPK）；Western blotting assay was used to determine the expression of Iba- 1，p-p38 MAPK，IL-1β，IL-6 and TNF-α in spinal dorsal horn of rats. RESULTS：Compared with sham operation group ，plantar pain threshold and area under the curve in model group were reduced significantly （P＜0.01）. Compared with model group ，plantar pain threshold increased significantly after 5，6，7 days of administration in 8-OaS low-dose group （P＜0.05），plantar pain threshold and area under the curve in 8-OaS medium-dose and high-dose groups were increased significantly （P＜0.05 or P＜0.01）. Most of above indexes in each dose group of 8-OaS were signifficantly different ，and ED 50 of 8-OaS was 18.87 μ g/kg. Results of immunohistochemistry staining and Western blotting showed that p-p 38 MAPK was mainly expressed in Iba- 1 positive cells. Compared with sham operation group ，the fluorescence density of Iba- 1 and p-p 38 MAPK in spinal dorsal horn ，the expression of Iba-1，p-p38 MAPK，IL-6，IL-1β and TNF-α were significantly increased in model group（P＜0.05 or P＜0.01）. Compared with model group ，the fluorescence density of Iba- 1 and p-p 38 MAPK in spinal dorsal horn ，the expression of Iba- 1，p-p38 MAPK， IL-6，IL-1β and TNF-α were decreased significantly in 8-OaS group （P＜0.05）. CONCLUSIONS ：Intrathecal administration of 8-OaS can effectively alleviate chronic inflammatory pain in rats. The mechanism may be related to the inhibition of the phosphorylation of p 38 MAPK and the expression of IL- 6，IL-1β and TNF-α.
ABSTRACT
Objective:To investigate the clinical effects of mini-hook locking plate fixation for the treatment of avulsion intra-articular fractures of the metacarpophalangeal joint.Methods:A retrospective case series study was conducted to analyze the clinical data of 13 patients with avulsion intra-articular fractures of the metacarpophalangeal joint admitted to Beijing Luhe Hospital of Capital Medical University from June 2016 to December 2017. There were nine males and four females, aged 22-61 years [(46.0±1.3)years]. All patients had closed fracture. According to Pechlaner classification, there were 5 patients with Grade A1 and 8 patients with Grade B1. All fractures were treated with open reduction and mini-hook locking plate internal fixation. Operation time, intraoperative blood loss, internal fixation position and bone healing time were recorded. The target joint range of motion (ROM) and grip strength were compared with the contralateral side two months after operation. Hand function was evaluated by total active motion (ATM). Visual analogue scale (VAS) was evaluated before operation two months after operation. Intraoperative and postoperative complications were recorded.Results:All the patients were followed up for 9-19 months [(11.3±1.1)months]. The operation lasted for 20-30 minutes [(25.5±1.3)minutes], with blood loss of 5-10 ml [(5.5±1.3)ml]. After operation, anatomical reduction was achieved in all patients and position of implant placement was suitable. Bone healing time was 4-8 weeks [(4.7±0.3)weeks] for all fractures. There were no significant differences in the target joint ROM compared with the contralateral side two months after operation ( P>0.05). ATM was excellent in 11 patients and good in 2, with excellent rate of 100%. VAS was significantly decreased from preoperative (5.9±1.1)points to (0.5±0.1)points two months after operation ( P<0.05). No internal fixation failure or wound infection occurred after operation. Conclusion:For avulsion intra-articular fractures of the metacarpophalangeal joint, mini-hook locking plate internal fixation has advantages of shortened operation time, rigid internal fixation after anatomical reduction, shortened bone healing time, fast recovery of hand function, obvious pain relief and few complications, which provides a treatment alternative for clinics.