ABSTRACT
ObjectiveTo observe the changes in the expression and distribution of G protein-gated inwardly rectifying potassium channel subunit 2 （GIRK2） in the dorsal root ganglion （DRG） and spinal cord dorsal horn of rats with remifentanil-induced hyperalgesia. MethodsHyperalgesia was induced by intravenous infusion of remifentanil 4 μg/kg/min for 2 h in adult male SD rats. At 6th hour and on days 1， 3 and 5 following remifentanil treatment， we used immunofluorescence to examine the changes in the GIRK2 distribution and expression. Immunoblotting was used to detect GIRK2 expression of the total protein and membrane protein in DRG and spinal dorsal horn of rats. Behavioral testing was applied to evaluate the effect of intrathecal injection of GIRK2-specific agonist ML297 on thermal nociceptive threshold on day 1 after remifentanil infusion. Resultsmmunofluorescence results showed that GIRK2 was mainly co-localized with IB4-positive small neurons in DRG and nerve fibers in spinal dorsal horn. GIRK2 expression was significantly downregulated following remifentanil treatment. Immunoblotting results revealed that on day 1 following intravenous infusion of remifentanil， compared with those in the control group， GIRK2 expression levels of the total protein and membrane protein in DRG （0.47 ± 0.10 vs. 1.01 ± 0.17， P < 0.001； 0.47 ± 0.11 vs. 1.06 ± 0.12， P < 0.001） and spinal dorsal horn （0.52 ± 0.09 vs. 1.10 ± 0.08， P < 0.001； 0.54 ± 0.10 vs. 1.01 ± 0.13， P < 0.001） were all significantly decreased. The behavioral results showed that intrathecal ML297 effect on thermal withdrawal latency was significantly reduced following remifentanil treatment （P < 0.001）. ConclusionsRemifentanil might induce hyperalgesia via down-regulating GIRK2 expression in rat DRG and spinal cord dorsal horn.
ABSTRACT
<p><b>OBJECTIVE</b>To discuss the effect of the use of the cervical lateral mass plates screws and T(1) pedicle screws for the treatment of C(6) to C(7) injury through posterior approach.</p><p><b>METHODS</b>There were 8 patients in the study group; Each of them had been injured with low cervical spine C(6) or C(7). There were 6 cases with C(6)-C(7) injury and 2 cases with C(7) injury. According to ASIA classification, 3 cases were in grade C and 5 cases in D. The lateral mass screws were placed on the lateral masses using Margel technique. Lamina or facet bone allografting were used to achieve a long-term stability.</p><p><b>RESULTS</b>All 8 patients were followed up from 5 to 37 months (mean 15 months). No operative death occurred. There were no cord or vertebral artery injury, cerebrospinal fluid leak, nerve roots injury, screw malposition or back out, loose of alignment or implant failure. Clinical symptom and ASIA classification were improved in all patients. Postoperative MRI scanning confirmed satisfactory screw placement in all cases.</p><p><b>CONCLUSION</b>This technique is safe and benefit to patients with low cervical spine C(6) or C(7) injury.</p>
Subject(s)
Adult , Female , Humans , Male , Middle Aged , Bone Screws , Cervical Vertebrae , Wounds and Injuries , General Surgery , Follow-Up Studies , Spinal Fusion , Methods , Spinal Injuries , General SurgeryABSTRACT
<p><b>OBJECTIVE</b>To treat injury of the lower cervical spine C6 to C7 with cervical lateral mass plates and T1 pedicle screws through posterior approach.</p><p><b>METHODS</b>The data of 8 patients with lower cervical spine C6 or C7 injury (6 patients with fracture and dislocation in C6 and C7 and 2 with fracture in C7) were analyzed retrospectively in this study. For the preoperative American Spinal Injury Association (ASIA) classification, Grade C was found in 3 cases and Grade D in 5 cases. Screws were placed on the lateral masses and the first thoracic pedicle with Margerl technique. Lamina or facet bone allografting was used to achieve a long-term stability.</p><p><b>RESULTS</b>All the 8 patients were followed up for 5-37 months (mean: 15 months). No operative death occurred. There were no examples of aggravation of spinal cord injury or vertebral artery injury, cerebrospinal fluid leak, nerve roots injury, screw malposition or back-out, loose of alignment or implant failure. Clinical symptoms and ASIA classification were improved in all the patients. Postoperative MRI scanning confirmed the satisfactory screw placement in all the cases.</p><p><b>CONCLUSIONS</b>Lateral mass plates and pedicle screws through posterior approach are safe and beneficial for patients with lower cervical spine C6 or C7 injury.</p>