BACKGROUND:In treatment of lumbar diseases, lumbar fusion therapy fails in 20%of cases and may lead to a series of complications such as pain, intervertebral space col apse, and delayed kyphosis deformity.
OBJECTIVE:To observe the effect of nucleus pulposus on interbody fusion after removing the anterior column disc of rabbit lumbar vertebra.
METHODS:A total of 36 healthy Japanese white rabbits were randomly and equal y divided into three groups, with 12 rabbits in each group. (1) Group of anterior longitudinal ligament+bone grafting:The L3 intercalated disc were wel exposed and anterior longitudinal ligament was stripped, obtaining a space to L3 intercalated disc, then the iliac bone was implanted. (2) Group of excising anterior 1/3 disc+bone grafting:After the anterior 1/3 disc tissue was excised, the iliac bone was implanted and sutured as Group of anterior longitudinal ligament+bone grafting. (3) Group of excising anterior 1/3 disc+fixation:After the anterior 1/3 disc tissue was excised, the iliac bone was implanted and the anterior column fixation was performed.
RESULTS AND CONCLUSION:Biomechanical testing showed that, at 12 weeks, the verticality tensile force in the group of anterior longitudinal ligament+bone grafting was obviously higher than other two groups, and have better fusion rate and could bear stronger force. Lateral position lumbar radiography showed that, the bone graft was absorbed and no new bone grew into the intervertebral space in the group of excising anterior 1/3 disc+bone grafting at 12 weeks;the formation of osseous bridge was found in the group of excising anterior 1/3 disc+fixation;complete bony fusion was found in the group of anterior longitudinal ligament+bone grafting. Histological examinations showed that, at 12 weeks, no bone tissue formed in the group of excising anterior 1/3 disc+bone grafting;a smal amount of bone trabecula and osteocytes were observed in the group of excising anterior 1/3 disc+fixation;a great quantity of newborn bone trabecula and osteocytes, remodeling lamel ar bone and canalis haversi structure were observed in the group of anterior longitudinal ligament+bone grafting. The stability of anterior column has notable effect on interbody fusion, after the anterior column disc is destroyed, the free nucleus pulposus may affect spinal fusion, so restoring the stability of the anterior column may promote interbody fusion, but stil cannot get solid spinal fusion.

BACKGROUNDLivin is a novel inhibitor of apoptosis protein(IAP),recent studies showed that it overexpressed in many carcinomas including lung cancer and contributed much to the cancerous development.The objective of this study is to explore the expression of the two isoforms of livin in lung cancer tissues and their relationship with histological types and chemotherapy,and to explore their relationship to the expression of caspase-3 as well.

METHODSExpression of livin α,livin β and caspase-3 mRNAs were detected by reverse transcription polymerase chain reaction(RT-PCR) assay in lung cancer tissues as well as in controls.

RESULTSLivin α and livin β were expressed in 12 of 27 and 19 of 27 lung cancer tissues respectively,much higher than those in lung para-cancerous(0/6,0/6) or benign disease lung tissues(0/12,1/12)(both P < 0.01).Moreover,the positive rate was 7/14 and 9/14 in lung adenocarcinoma and 4/12 and 9/12 in squamous and large cell carcinoma respectively,and both of them were detected in one small cell carcinoma.The levels of these two isoforms in lung cancer were significantly higher than those in controls by Gel Imaging System(both P < 0.05),the level of livin α was remarkably higher in adenocarcinoma than that in squamous cell carcinoma(P < 0.05),while the level of livin β was similar in both carcinomas(P > 0.05).Meanwhile,the level of caspase-3 in lung cancer was significantly lower than that in controls,the levels of either each of two isoforms or their sum were negatively associated with that of caspase-3(P < 0.05,P < 0.01,P < 0.01).Two isoforms of livin mRNA expression seemed to increase after chemotherapy but not related to clinical stages(P > 0.05).

CONCLUSIONSTwo isoforms of livin are differently expressed in different histological types of lung cancer and may contribute to corresponding cancerous development;the levels of livin are negatively associated with those of caspase-3,this may due to the fact that livin could resist against apoptosis;high expression of livin seems to be related to chemotherapy but not clinical stage.