Ex Vivo Observation of Human Nucleus Pulposus Chondrocytes Isolated From Degenerated Intervertebral Discs

STUDY DESIGN: We performed an ex vivo study to observe cell morphology and viability of human nucleus pulposus (NP) chondrocytes isolated from degenerated intervertebral discs (IVD). PURPOSE: To better understand the biological behavior of NP chondrocytes in monolayer cultures. OVERVIEW OF LITERATURE: Biological repair of IVDs by cell-based therapy has been shown to be feasible in clinical trials. As one of the most promising transplanting seeds, how the isolated NP chondrocytes behavior ex vivo has not been fully understood. METHODS: Human NP chondrocytes were harvested from 20 degenerated IVDs and cultured in monolayers. Histological and immunochemistry staining was used to detect cell morphology change. Cell viability was studied by analyzing cell cycle distribution and apoptotic rate in the primary and subculuted cells. RESULTS: The round or polygonal primary NP chondrocytes had an average adherence time of 7 days and took nearly 31 days to reach 95% confluence. The spindle-shaped P1 NP chondrocytes increased growth kinetics and took about 12 hours to adhere and 6.6 days to get 95% confluent. Immunochemistry staining of collagen II was positive in the cell cytoplasm. Nearly 90% of the confluent NP chondrocytes stayed in G1 phase while 16% underwent apoptosis. No significant difference of the collagen II expression, cell cycle distribution or the apoptosis indices were detected between the primary and subcultured NP chondrocytes. CONCLUSIONS: Human NP chondrocytes undergo significant morphological change in monolayer cultures. Cell cycle distribution pattern and apoptosis index of the cutured NP chondrocytes potentially influence their clinical transplantation or laboratory use.

Clinical assessment of one-level posterior lumbar interbody fusion performed with microendoscopic approach / 中华显微外科杂志

Objective To evaluate the clinical outcome of one-level posterior lumbar interbody fusion (PLIF) performed with microendoscopic approach.Methods A consecutive series of 56 patients who under went one-level PLIF procedure(24 cases performed with microendoseopic approach and 32 cases with tradition- al open approach)were studied from January 2005 to May 2006.The following data were compared between 2 groups with 12 to 27 months follow-up:estimated blood loss,postoperative drainage,transfusion needs,surgi- cal time,length of hospital stay,postoperative back pain by visual analogue scale,complications,and the clinical and radiographic results.Results The microendoscopic approach was found to have a significantly less blood loss,less postoperative drainage,less needs of transfusion,less postoperative back pain,shorter re- covery time and shorter length of hospital stay.However,the microendoscopic approach needed significantly longer surgical time.There was no significant difference between 2 groups in the aspects of the complications and the clinical and radiographic results.Conclusion The one-level PLIF performed with microendoscopic approach minimize estimated blood loss,length of hospital stay,postoperative back pain.It also shows the ex- cellent surgical efficacy of the microendoscopic approach for suitable patients.