Effects of Selective Cyclooxygenase-2 Inhibitor NS-398 Pretreatment on the Rat Spinal Cord after Contusion Injury

BACKGROUND: Secondary spinal cord injury (SCI) that follows an initial mechanical insult can exacerbate the overall damage, limit the restorative processes and eventually lead to an in- creased neurological deficit. We hypothesized that selective inhibition of cyclooxygenase-2 (COX-2) may decrease the delayed cell death, and so this will contribute to decreased level of the secondary injury. METHODS: The dorsal surface of the cord at the T9 level was subjected to weight drop impact using a 10 g rod. To block COX-2 activation, a selective COX-2 inhibitor (NS-398) was administered (5 mg/kg, i.p.) 15 min prior to SCI. The COX-1, COX-2, Caspase-3 and PGE2 expressions were measured by real time quantitative RT-PCR and fluorescence immunostaining. RESULTS: Many activated caspase-3 positive cells were observed at 6 h and they increased until 72 h after SCI. The expression of COX-2 peaked at 6 h after SCI, while the COX-1 expression was unaffected. The principal cells that showed a COX-2 expression were the neurons and microglia. Pretreatment with NS-398 caused a significant decrease in the expression of prostaglandin E2 and activated caspase-3 positive cells after SCI. CONCLUSION: These data suggest that COX-2 is one of the main factors related with the pathologic deficits from secondary SCI.

Posterior Approach for Cervical Spondylosis with Radiculomyelopathy

Of the 68 cervical spondyltic patients showing symptoms of radiculomyelopathy, assessments were made on 29 patients who underwent neural decompressive surgery with cervical laminectomy through posterior approach for the results of surgery. Analyses were also made on the anterior-posterior diameters of cervical canal on the plain film of cervical spine. The mean values of anterior-posterior diameters measured on the levels of cervical C3-7 were 16.5+/-1.83 mm in the normal adult and 7.3+/-1.08 mm in the cervical spondylotic patients with radiculomyelopathy, which is far narrower than that of the normal. In cervical spondylotic patients, the anterior-posterior diameters of directly upper and lower parts of the lesions were 11.9+/-1.20 mm and 12.1+/-1.61 mm respectively, also much narrower mean values than those of the normal control group. The results of the 29 patients who received cervical laminectomy by posterior approach were much improved for 51.7% and improved for 44.8%.

Rebleeding of Intracranial Aneurysm with SAH

The followings were evaluated as subjects of this study on 79 rebleeding cases of the 312 ruptures aneurysmal patients : incidence, time of rebleeding, location of rebleeding aneurysm, together with clinical grade and results of rebleeding. The incidence of rebleeding was 25.3% without prominent distinction between sexes. In the rebleeding rats by location, MCA aneurysm was found to be highest(30.8%) with no statistical significance. The 36.7% rebleeded in a week after initial bleeding, which indicates a daily average incidence of 5.3%. From one week on, the bleeding rate tapered off. Favorable risk patients showed a significantly higher rate(36.8%) compared with poor risk patients(6.7%). The mortality rate by rebleeding was 6.3%.