Construction, expression and refolding of recombinant luteinizing hormone releasing hormone-angiogenin toxin / 中华耳鼻咽喉头颈外科杂志

<p><b>OBJECTIVE</b>To express, purify and refold recombinant luteinizing hormone releasing hormone-angiogenin (LHRH-Ang) toxin using E. coli. expression system.</p><p><b>METHODS</b>Recombinant LHRH-Ang expression vector was constructed by replacing of EGF fragment in plasmid pET28a/EGF-Ang with LHRH-PII fragment amplified from plasmid pET28/MSH-PE40. DNA sequencing would be used to verify the correction of fused LHRH-PII-Ang gene. Then, E. coli strain BL21 (DE3) was transformed by pET28a/LHRH-Ang vector. Expression of recombinant LHRH-Ang toxin was induced by Isopropyl-β-D-Thiogalactoside (IPTG). Refolding effects of gradient dialysis was evaluated by SDS-PAGE.</p><p><b>RESULTS</b>Prokaryotic expression vector pET28a/LHRH-Ang, containing LHRH-PII-Ang fusion gene, was constructed by PCR amplification, restriction enzyme digestion and ligation method. Sequence correction of fusion gene was confirmed by DNA sequencing. After IPGT induction, recombinant LHRH-Ang protein was expressed in BL21 (DE3) as inclusion body, it took 18.43% of total protein. Inclusion body was resolved in 8 mol/L urea and purified by DEAE-Sepharose FF column, the purity was 85%. Recombinant LHRH-Ang toxin was refolded and concentrated by gradient dialysis and PEG 20000, respectively.</p><p><b>CONCLUSIONS</b>Recombinant LHRH-Ang protein was expressed in E. coli and refolded successfully.</p>

Endoscopic endonasal surgery for clival tumor / 中华耳鼻咽喉头颈外科杂志

<p><b>OBJECTIVE</b>To review our experience with endoscopic endonasal approach for surgical management of clival tumors.</p><p><b>METHODS</b>Twenty-four patients with clival tumors treated by endoscopic endonasal surgery between August 2002 and November 2005 were studied prospectively. The operative technique was described in detail. There were 5 chordoma, 2 ossifying fibroma, 1 meningioma, 1 craniopharyngioma, 1 hemangioblastoma, 6 squamous cancer, 2 chondrosarcoma, 2 chondrosarcoma, 1 lymphoma, 1 malignant giant cell tumor and 2 metastatic carcinoma.</p><p><b>RESULTS</b>Total tumor removal was obtained in 22 cases, subtotal removal in 2 case. Follow-up ranged 12 to 51 months. Three patients dead. Five patients with total removal recurred, one of them dead. Two patients with subtotal removal dead, one with chondrosarcoma and one with chordoma. The complications included subarachnoid hemorrhage in 1 patient, and transient cerebrospinal leakage in 2 cases.</p><p><b>CONCLUSIONS</b>The use of nasoendoscopy to perform clival tumor surgery is not only limited to the minimally invasive aspect, it also provides better visualization of deeper structures in the skull base, provides the ability to 'look around corners' and wide exposed field. This approach permits us to manage clival lesions properly.</p>

Using of titanium mesh for the reconstruction of skull base defect / 中华耳鼻咽喉头颈外科杂志

<p><b>OBJECTIVE</b>The purpose of this study is to evaluate the possibility and surgical principle of titanium mesh used for the reconstruction of skull base bone defect.</p><p><b>METHODS</b>The clinical data of 11 patients with defect of skull base bone repaired with titanium mesh were retrospectively analysed.</p><p><b>RESULTS</b>Among 11 patients, there were 6 patients with skull base tumor, 3 patients with fibrosis hyperplasia, 2 patients with encephalomeningocele. The surgical approach included craniofacial approach in 7 patients, transfrontal and extended transfrontal approach in 3 patients, trans-midface approach in 1 patient. The anterior and lateral skull base was repaired in 2 patients, anterior and middle skull base and sellar repaired in 6 patients, anterior skull base and orbital floor repaired in 3 patients. In early postoperative period, there were 3 patients with intracranial pneumatosis, but without symptom, and 1 patient with transient cerebrospinal leakage. Following-up for average 14.4 months, there was no titanium mesh displacement and intracranial infection in all patients.</p><p><b>CONCLUSIONS</b>The titanium mesh used for the repair of skull base bone defect was both possible and safe.</p>