OBJECTIVETo construct pPICZalphaA-soluble interleukin-1 receptor type I (sIL-1RI) recombinant expression vector containing the gene fragment encoding the extracellular domain of sIL-1RI for its expression in Pichia pastoris.

METHODSsIL-1RI gene was amplified by RT-PCR and inserted into the yeast expression vector pPICZalphaA by digestion ligation. The recombinant plasmid pPICZalphaA-sIL1RI was transformed into E.coli Stb13, and the positive clones were analyzed by PCR and DNA sequencing. The pPICZalphaA-sIL1RI recombinant plasmid was electroporated into GS115 cells and the transformants were analyzed by PCR. After phenotype identification, the recombinant strains were induced by methanol to express the target protein, which was analyzed by Western blotting of the cell extract and supernatant.

RESULTSThe recombinant plasmid pPICZalphaA-sIL-1RI was constructed successfully, and the results of Western blotting showed that yeast induced by methanol expressed a protein of about 39 kD.

CONCLUSIONsIL-1RI protein has been successfully expressed in P.pastoris expression system, which provides the basis for further study of sIL-1RI.

Escherichia coli ; metabolism ; Gene Expression ; Genetic Vectors ; Humans ; Pichia ; metabolism ; Plasmids ; Receptors, Interleukin-1 Type I ; biosynthesis ; genetics

Introduction: Both short and long PFNA are employed to treat intertrochanteric fractures. Controversy exists in the choice between the two nails as each implant has specific characteristics and theoretical advantages. This retrospective study seeks to examine the operative complication rates and clinical outcomes of short versus long (Proximal Femoral Nail Antirotation) PFNA in the treatment of intertrochanteric fractures. Materials and methods: Between July 2011 and February 2015, 155 patients underwent PFNA insertion. The decision on whether to use a short or long PFNA nail, locked or unlocked, was determined by the attending operating surgeon. Visual Analogue Pain Score (VAS) Harris Hip Scores (HHS), Short-form 36 Health Questionnaire (SF-36) and Parker Mobility Scores (PMS) were collected at six weeks, six months and one year post-operatively. Results: A total of 137 (88.4%) patients were successfully followed-up. Forty-two (30.7%) patients received a short PFNA. The patients were similar in baseline characteristics of age, gender, and comorbidities. Operative time was significantly longer in the short PFNA group (62 ±17 mins) versus the long PFNA group (56±17). While the patients in both groups achieved improvement in all outcome measures, there was no significant difference between the groups in terms of HHS (61.0 ±16.0 vs 63.0 ±16.8, p=0.443), PMS (2.3±1.5 vs 2.7±2.1, p=0.545) and VAS (1.7±2.9 vs 1.8 ±2.2 p=0.454). There were 3 (7.1%) and 7 (7.4%) complications in the short versus long PFNA group, respectively. Conclusion: Both short and long PFNA had similar clinical outcomes and complication rates in the treatment of intertrochanteric fractures in an Asian population.