Percutaneous full endoscopic posterior decompression of thoracic myelopathy caused by ossification of the ligamentum flavum.

PURPOSE: Ossification of ligamentum flavum (OLF) is the leading cause of progressive thoracic myelopathy (TM) in East Asian countries. Surgical decompression is the general treatment for TM. This study investigated the application of percutaneous full endoscopic posterior decompression (PEPD) for the treatment of thoracic OLF. METHODS: Eighteen patients with TM were treated by PEPD under local anaesthesia. Patients had an average age of 59.1 years and single-level lesions mostly at the lower thoracic vertebrae. Computed tomography and magnetic resonance imaging were used to classify the OLF. The pre- and postoperative neurological statuses were evaluated using the American Spinal Injury Association (ASIA) sensory and motor score, modified Japanese Orthopaedic Association (mJOA) score and Frankel grade. RESULTS: OLF for all patients was classed as lateral, extended, and enlarged types without comma and tram track signs. Decompression was completed, and a dome-shaped laminotomy was performed through limited laminectomy and flavectomy. Dural tears in 2 patients were the only observed complication. The average score of ASIA sensory and motor, mJOA, as well as the Frankel grade improved significantly after surgery at an average follow-up time of 17.4 months. The average recovery rate (RR) was 47.5% as calculated from the mJOA scores. According to RR, 10 cases were classified as good, 4 cases fair, and 4 cases unchanged. CONCLUSIONS: For patients with thoracic OLF at a single level and lateral, extended, and enlarged types without comma and tram track signs, it is safe and reliable to perform PEPD, which has satisfactory clinical results. These slides can be retrieved under Electronic Supplementary Material.

[Soil nitrogen content and enzyme activities in rhizosphere and non-rhizosphere of summer maize under different nitrogen application rates.] / æ–½æ°®é‡å¯¹å¤çŽ‰ç±³æ ¹é™ å’Œéžæ ¹é™ åœŸå£¤é ¶æ´»æ€§åŠæ°®å«é‡çš„å½±å“.

A field experiment was conducted on fluvo-aquic soil in the North China Plain to study the effects of nitrogen application rate on soil nitrogen contents and enzyme activities in rhizosphere and non-rhizosphere of summer maize. The results showed that the soil enzyme activities under different nitrogen application rates showed similar seasonal patterns. In comparison to no nitrogen ferti-lizer treatment, all nitrogen application treatments significantly increased NO3--N contents in rhizosphere and non-rhizosphere soils, NH4+-N content in rhizosphere soil and the activities of ß-N-acetylglucosaminidase, ß-glucosidase, ß-xylosidase and Cellobiohyrolase. During the whole summer maize growing season, the NO3--N content in non-rhizosphere soil was significantly higher than that in rhizosphere soil. The NH4+-N content in non-rhizosphere soil was also significantly higher than that in rhizosphere soil at filling stage but significantly lower at seedling and maturity stages. Furthermore, soil enzyme activities in rhizosphere soil were significantly higher than those in non-rhizosphere soil. Effect of nitrogen application on soil organic carbon content was not significant. Soil total nitrogen content increased significantly when the nitrogen application rate was 0-180 kg·hm-2 but decreased significantly when the rate was higher than 180 kg·hm-2. Generally, a proper rate of nitrogen fertilizer application could significantly increase soil enzyme activities and total nitrogen content, and then improve soil biochemistry properties.

[Mini-incision posterior laminectomy by fenestration in the treatment of huge lumbar disc herniation].

OBJECTIVE: To discuss clinical effects and methods of mini-incision posterior laminectomy by fenestration in the treatment of huge lumbar disc herniation. METHODS: From 1999 to 2008,107 patients with huge protruded lumbar intervertebral disc were retrospectively analyzed including 78 males and 29 females with an average age of 38.5 years ranging from 26 to 59 years. The patients were operated with mini-incision posterior laminectomy by fenestration. The affected region of patients were L4.5 (36 cases), L5S1 (71 cases). The herniation rate of nucleus was more than 40%. The patient's scores based on low back pain improved JOA standard were retrospectively analyzed. RESULTS: The 107 patients were followed-up for from 0.5 to 4 years with an average of 1.75 years. The scores by low back pain improved JOA standard were improved from (1.500 +/- 1.200) before operation to (12.700 +/- 0.950) after operation. The average improvement rate was (82.96 +/- 6.85)%. CONCLUSION: It is a reliable method in the treatment of huge lumbar disc herniation with mini-incision posterior laminectomy by fenestration. The treatment method have advantage with less trauma, good spinal stability, conducive to patient recovery and maintain clinical efficacy.