[Clinical application of titanium plate reconstruction of mandibular defect: 10 years of follow up].

OBJECTIVE: To summarize the postoperative complications of reconstruction of mandible defect with titanium reconstruction plate. METHODS: A total of 111 cases of the mandibular defect caused by various reasons and repaired by titanium reconstruction plate in the Department Oral and Maxillofacial Surgery of the affiliated Hospital of Qingdao University from 2003 to 2012 were collected and followed up. The complications were analyzed. RESULTS: Thirty-seven percent of 111 cases showed long term complications. The titanium fracture was the main complication(16%[18/111]), followed by stress-shielding (9%[10/111]), infection(8%[9/111]), and titanium plate exposure(4%[4/111]). Titanium plate fracture occurred within 8 months and 3 years after surgery. The simple titanium plate reconstruction had the highest rate of plate fracture(30%[15/50]). Stress-shielding in non-vascularized bone graft was more significant than that in vascularized bone graft(P<0.05). When replaced by mini-titanium plate, the stress-shielding effect disappeared gradually. When the retention of mandibular margin height was less than 1 cm with the use of reconstruction plate, the postoperative complications were prone to occur. CONCLUSIONS: Bone graft is the best way to reconstruct mandibular defect, and simple reconstruction plate repair is applied only as a transitional means for high degree of malignancy, obvious recurrence tendency tumor or special reasons such as age etc, which are not suitable for bone graft. The reconstruction plate fixation is not recommended for bone graft, especially non-vascularized bone graft. The retention of mandibular margin with reconstruction plate fixation is open to discussion.

An HSV-1 amplicon system for prostate-specific expression of ICP4 to complement oncolytic viral replication for in vitro and in vivo treatment of prostate cancer cells.

The aim of the present study was to determine whether a prostate-specific amplicon, containing a probasin-derived promoter (ARR(2)PB) upstream of an essential Herpes simplex virus-1 (HSV-1) viral gene, infected-cell polypeptide 4 (ICP4), could complement an HSV-1 helper virus with this gene deleted (ICP4-) and cause lytic replication specifically in prostate cancer cells. Two amplicon constructs, CMV-ICP4 and ARR(2)PB-ICP4, were packaged by a replication-deficient ICP4- helper virus. The amplicon viruses could complement ICP4- helper viruses to efficiently replicate and cause cell lysis in prostate cancer cells. Intratumoral injection of LNCaP human prostate cancer xenografts with either amplicon/helper virus resulted in >75% reduction in tumor volume and serum prostate specific antigen (PSA). Histological and Q-PCR (quantitative PCR) analyses indicated that the toxicity in nontumor tissues was much lower with ARR(2)PB-ICP4 than with CMV-ICP4 amplicon/helper virus. In conclusion, a replication-deficient HSV-1 virus could be complemented by an amplicon virus to restore its oncolytic activity in a tissue-specific and low toxicity fashion, illustrating that this approach could be a potentially useful strategy for developing an oncolytic viral therapy for prostate cancer.