Design and Evaluation of a Novel Laminectomy Auxiliary Device Based on Rats.

Most types of spinal cord injury (SCI) observed in humans can be replicated in adult rat models, which are widely used for laboratory studies of SCI rehabilitation. To ensure the effectiveness and efficiency of an SCI rat model, the minimal time spent performing the laminectomy procedure and the damage caused to the body are of great importance. We describe and evaluate the effectiveness and advantages of a laminectomy auxiliary device (LAD) for removing the rat vertebral lamina without injuring the spinal cord. The incision size, success rate, operation duration, body weight, BBB score, step detection, latency and amplitude of transcranial electrical motor-evoked potentials (tceMEPs), and serum MDA and SOD levels were recorded in 8 normal rats, 8 rats treated with traditional laminectomy and 8 rats treated with LAD laminectomy. Compared with traditional laminectomy, in our LAD, the surgical incision was smaller (approximately 2.2 and 1.3 cm, respectively), the success rate was higher (88.89% and 100%, respectively) and the duration shorter (14.644±1.617 and 4.821±0.668 minutes, respectively). Compared with normal rats, those treated with either laminectomy using LAD or the traditional method showed slower body weight gain and temporarily increased oxidative stress levels. However, there were no significant differences between these two groups. Our results show that laminectomy using this LAD provides three main advantages in rats: a high success rate, time savings, small incisions and reduced trauma. We believe this LAD can be used as an effective assistant tool for rodent laminectomy.

[Influence of escharectomy during shock stage on the systemic and intestinal immune function in scalded rats].

OBJECTIVE: To investigate the influence of escharectomy during shock stage on systemic and intestinal immune function and its mechanism in scalded rats. METHODS: Ninety-six Wistar rats were employed in the study of which 8 were used as normal control group. The donor skin from the trunk in twenty-four rats were preserved in liquid nitrogen. The other 64 rats were subjected to 30% full-thickness scalding, and they were randomly divided into A (n = 24, no treatment after scalding), B (n = 24) and C (n = 16) groups. Physiological saline was intraperitoneally injected (50 ml/kg) on the 24 post-scalding hours to the rats in the B and C groups. The rats in B group underwent escharectomy during shock stage, and the excision wounds were covered with the cryo-preserved alloskin. The rats in C group received the same treatment as in B group but at 72 post-scalding hours. The change in the proliferative ability of splenic lymphocytes, the plasma and intestinal tissue content of interleukin 2 (IL-2), the contents of sIgA in intestinal mucus, and the content of DAO in the intestinal tissue were observed on 2, 4 and 8 post burn days (PBD) in A and B groups and also on 4 and 8 PBD in C group, respectively. RESULTS: The splenocytic proliferative ability, IL-2 level in the plasma and intestinal tissue, and the sIgA content in intestinal mucus in the rats in A, B and C groups were lower than that in control group at all time points (P < 0.05). The proliferative ability of splenic lymphocytes in B group on 4 and 8 PBD and in C group on 8 PBD respectively was similar to that in control group. Whereas the IL-2 content in plasma and in intestinal tissue was higher in B and C groups than that in A group (P < 0.01). The sIgA content in intestinal mucus in B group was twice of that in C group respectively [(3.51 +/- 2.14) mg/g vs (1.40 +/- 0.64) mg/g, (3.03 +/- 0.95) mg/g vs (1.52 +/- 1.26) mg/g (P < 0.05 or P < 0.01)] on 4 and 8 PBD. The DAO activity in the intestinal tissue in A group was lower than that in control and B group (P < 0.05) on 4 and 8 PBD. CONCLUSION: Escharectomy during shock stage might be beneficial to the recovery of the systemic and intestinal immune functions in rats with scalding injury.

[Effects of carbachol on plasma levels of tumor necrosis factor-alpha and interleukin-10 in rats during gut ischemia-reperfusion].

OBJECTIVE: To investigate the effects of carbachol on the levels of tumor necrosis factor-alpha (TNF-alpha), interleukin-10 (IL-10) and cortisol in plasma of rats during gut ischemia-reperfusion. METHODS: Wistar rats were anaesthetized with soluble pentobarbitone, and subjected to superior mesenteric artery occlusion (SMAO) for 60 minutes, followed by reperfusion for 60 minutes. Animals were divided into three groups, pretreated group (intramuscular injection carbachol at 30 minutes after SMAO, 0.1 mg/kg), treated group (intramuscular injection of carbachol at 30 minutes after reperfusion), and control group (saline injected). The levels of TNF-alpha, IL-10 and cortisol in plasma were determined at 0 hour, 1 hour, 2.5 hours and 6 hours after SMAO. RESULTS: The levels of TNF-alpha, IL-10 and cortisol significantly increased after SMAO (P<0.01 ). The levels of TNF-alpha significantly decreased in pretreated and treated groups than that in control after the intramuscular injection of carbachol (all P<0.01). However, the levels of IL-10 and cortisol did not show significant differences among three groups. It was also found that lower content of TNF-alpha in pretreated group than that in treated group, especially at 1 hour and 6 hours. CONCLUSION: The results suggest that carbachol reduce the proinflammatory cytokine releasing and has a less inhibiting effect on the anti-inflammatory cytokine. It is indicated that carbachol play a potential role in alleviating systemic inflammatory response during splanchnic ischemia-reperfusion injury.