Percutaneous transforaminal endoscopic TESSYS technique for the treatment of bilateral lumbar disc herniation in single segment / 中国骨伤

OBJECTIVE@#To investigate the early clinical effects of transforaminal endoscopic spine system (TESSYS) for the treatment of bilateral lumbar disc herniation in single segment.@*METHODS@#The clinical data of 38 patients with single-segment bilateral lumbar disc herniation treated by TESSYS technique from February 2016 to February 2018 were retrospectively analyzed. There were 26 males and 12 females, aged from 30 to 55 years old with an average of(35.2±6.4) years, 6 cases of L₃,₄, 22 cases of L₄,₅, and 10 cases of L₅S₁1. Using the intervertebral foramen endoscope produced by Joimax GmbH, Germany, under local anesthesia, bilateral puncture to the outside of the intervertebral foramen of the diseased segment, four-stage dilatation catheter to complete the progressive enlargement of the intervertebral foramen, and the ring saw progressively enlarge the intervertebral foramen. The bilateral foramen was placed and the herniated nucleus was removed until the nerve root was completely released. Postoperatively, the patients were reviewed on regular outpatient visits and telephone follow-ups. Visual analogue scale (VAS) and Oswestry Disability Index (ODI) were compared before operation and after operation at 1, 3, 6, 12 months respectively. At the final follow-up, according to modified MacNab criteria to evaluate the clinical effect.@*RESULTS@#Thirty-six patients underwent successful surgery and were followed up for more than 12 months. The ODI score and VAS score of the lower extremities pain at 1, 3, 6, 12 months after operation were obviously improved (0.05). At the final follow-up, according to MacNab criteria, 14 cases got excellent results, 16 good, 4 fair, 2 poor.@*CONCLUSIONS@#Using TESSYS technique to remove the bilateral herniated nucleus from single segment can fully decompress for the nerve root, and can be effectively applied to patients with single-segment bilateral lumbar disc herniation.

Design and animal study of a posterior instrumentation system with sliding ring pedicle screws without arthrodesis in the immature spine / 中华外科杂志

<p><b>OBJECTIVE</b>To evaluate a sliding ring pedicle screw system without arthrodesis for the treatment of scoliosis in the immature spine.</p><p><b>METHODS</b>Twelve goats of 3 months old were randomized into three groups: limited anchoring group, multi anchoring group, and blank contrast group. Growth of the spine and sliding of the instruments were assessed through conventional radiography and three dimensional CT reconstruction scan. Vertebral columns were resected 3 months after operation and pathological sections were observed.</p><p><b>RESULTS</b>Three-dimensional CT scan and pathological analysis indicated no difference in structural development of the instrumented segments of the spine in the two operated groups as compared with the same segments of the spine in the control group. According to gross anatomic evaluation and radiographic measurement, the increase in height from L5 to T10 averaged 43.0 mm in limited anchoring group, 43.5 mm in multi anchoring group and 40.9 mm in blank contrast group. Total sliding in the instrumentation system was 41.2 mm in limited anchoring group and 39.4 mm in multi anchoring group, respectively. There were no statistically significant difference in the longitudinal growth of the spine among the three groups.</p><p><b>CONCLUSIONS</b>The sliding ring pedicle screw system can glide smoothly to accommodate the growth of the immature spine in an in vivo animal model.</p>

High-cell density cultivation of recombinant Escherichia coli for production of TRAIL by using a 2-stage feeding strategy / 生物工程学报

Escherichia coli was genetically engineered to produce recombinant tumor necrosis factor-related apoptosis inducing ligand (Apo2L/TRAIL) using a temperature-inducible expression system. To create a fed-batch culture condition that allows efficient production of TRAIL, different feeding strategy including discontinuous, DO-stat and pH-stat feeding strategies were compared. Then, a special 2-stage feeding strategy was developed. High concentration of biomass (300g wet cell weight per liter of culture broth) and active soluble TRAIL protein (1.1g/L) was obtained by applying a high-cell-density cultivation procedure with the 2-stage feeding strategy. Cultivation of recombinant E. coli was started as a batch process at 30 degrees C and then followed by fed-batch culture when the dissolved oxygen concentration presented a steep increase resulted from the exhaustion of glucose in the medium. At the first phase of fermentation (batch phase), agitation rate was enhanced to control dissolved oxygen at 30 percent. When glucose in the medium was used up, indicated by a sudden rise in pH value and dissolved oxygen, the second phase (fed-batch phase) was started with glucose and nitrogen resource being supplied automatically. At the beginning of fed-batch operation, stirrer rate was cascaded with dissolved oxygen signals to keep it at 20 percent (DO-stat). During the fed-batch phase, glucose was limited to control the specific growth rate under the critical value microcrit, to avoid acetic acid excretion. When the stirrer speed arrived at its up-limit, the flow rate of feed was kept constant. In the inducing phase(42 degrees C for 4h) glucose was fed as a pH regulating agent (pH-stat) and the specific growth rate and dissolved oxygen decreased sharply. Aqueous ammonia was used for maintaining pH value at 7.0 throughout the first two phases. In the whole fermentation, acetic acid concentration didn't exceed 2.9 g/L. At the end of the high-cell-density cultivation process, no acetic acid could be detected in the medium. These results indicated that our fed-batch strategy was able to prevent acetate accumulation significantly. Although high cell density has been achieved, the induction process was not optimized satisfactorily and much work should be done further. Furthermore, since no special ways, like pure oxygen, pressure, has been used in our experiments, this efficient approaches would be useful not only in a pilot scale but also in an industry scale. Finally, simple purification procedure based on immobilized metal affinity column (IMAC) and CM-Sepharose column was implemented to isolate the TRAIL. Yields of more than 800mg TRAIL per liter of culture broth were obtained, the final purity reaching more than 95%. The purified TRAIL showed strong cytotoxity activity against human pancreatic 1990 tumor cells, with ED50 about 1.6 microg/mL.