[Expression of NF-kappaB and TNF-alpha in spinal dorsal horn in a rat model of neuropathic pain].

OBJECTIVE: To investigate the expressions of NF-kappaB and TNF-alpha in lumbar spinal cord in a rat model of chronic constrictive injury (CCI). METHODS: Seventy-six male SD rats were randomly divided into 2 groups (n = 38 each): CCI group receiving chronic constriction injury and sham group receiving sham operation as control. The mechanical and thermal nociceptive thresholds were assessed with paw withdrawal latency (PWL) to von Frey filaments and radiant heat at different time points. Five animals were sacrificed at each time point for real-time polymerase chain reaction (real-time PCR) and another three animals sacrificed at 7 d post-operation for double-immunofluorescence histochemical staining. Lumbar segments of spinal cord were removed. The expressions of NF-kappaB and TNF-alpha in spinal cord were examined by real-time PCR and double-immunofluorescence histochemical technique. RESULTS: The post-operative thresholds to mechanical and thermal stimuli decreased obviously. As compared with contralateral side and sham group, the expressions of NF-kappaB and TNF-alpha mRNA increased significantly in ipsilateral spinal dorsal horn. Their expressions began to increase at 4 d post-operation and peaked at 7 d. Then TNF-alpha began to decrease while NF-kappaB maintained at a high level throughout the experiment. Double-immunofluorescence histochemical staining revealed extensive co-localization of NF-kappaB with TNF-alpha on ipsilateral side of dorsal horn. CONCLUSION: The activation of NF-kappaB and its downstream inflammatory mediators may be involved in the regulation of neuropathic pain.

Treatment of lumbar intervertebral disc herniation using C-arm fluoroscopy guided target percutaneous laser disc decompression.

OBJECTIVE: To evaluate the safety and therapeutic efficacy of target percutaneous laser disc decompression (T-PLDD) for the treatment of lumbar disc herniation. BACKGROUND DATA: PLDD using the Nd:YAG laser has been regarded as an effective alternative treatment for disc herniation. However, all the previous studies were concentrated on vaporizing the nucleus pulposus in the intervertebral space. We hypothesize that insertion of the needle into the extruded part of the nucleus pulposus will decrease its volume and provide superior clinical effects compared to therapies that decrease the volume of the intradiscal nucleus pulposus. MATERIALS AND METHODS: A total of 25 patients suffering from posterolateral extruded but nonsequestered lumbar intervertebral disc herniation were treated with T-PLDD. After treatment, the patients were followed up and the therapeutic effect was assessed at 1, 3, 6, and 12 months using the modified MacNab criteria. RESULTS: The success rate was 80.0% (18 of 25), 88.0% (22 of 25), 92.0% (23 of 25), and 92.0% (23 of 25) at 1, 3, 6, and 12 months respectively. No serious complications occurred in any of the patients. Furthermore, we did not observe any neurological sequelae. CONCLUSIONS: T-PLDD can significantly decrease pain and improve function of patients who have extruded but nonsequestered lumbar intervertebral disc herniation.

[Effect of electroacupuncture on the expression of spinal glial fibrillary acidic protein, tumor necrosis factor-alpha and interleukin-1beta in chronic neuropathic pain rats].

OBJECTIVE: To observe the effect of electroacupuncture (EA) on the expression of spinal glial fibrillary acidic protein (GFAP), tumor necrosis factor-alpha (TNF-alpha) and interleukin-1beta (IL-1beta) in chronic constriction injury (CCI) rats. METHODS: Seventy-two SD rats were randomized into sham operation (sham), CCI (model) and EA groups (n = 24/group). The mechanical and thermal pain thresholds were measured by using Von Frey filaments and radiant-heat irridiation separately. The immunoactivity of GFAP of spinal dorsal horn (L4-L5) was assessed by immunohistochemistry, and the expression of spinal TNF-alpha mRNA and IL-1beta mRNA was detected by real time-PCR. RESULTS: Compared with pre-CCI and sham group, both mechanical and thermal pain thresholds decreased considerably in rats with CCI (P < 0.05), and in comparison with model group, those of EA group increased markedly (P < 0.05). Compared with sham group, GFAP immunoactivity (mainly in the lamina I-II of the spinal dorsal horn), TNF-alpha mRNA and IL-1beta mRNA expression in the ipsilateral spinal cord on the CCI side in model group increased considerably (P < 0.05), while compared with model group, the expression of GFAP, TNF-alpha mRNA and IL-1beta mRNA in EA group was down-regulated remarkably (P < 0.05). CONCLUSION: EA can effectively suppress CCI-induced up-regulation of expression of spinal GFAP, TNF-alpha mRNA and IL-1beta mRNA, which may contribute to its effect in reducing mechanical allodynia and thermal hyperalgesia in neuropathic pain rats.