BACKGROUND: Hepatic oval cells (HOCs) possess the potential of self-renewal, replication, and clone, proliferation and differentiation into mature hepatocytes under a certain condition. HOCs can be used as biomaterial for constructing biological artificial liver in vitro, employed for in vivo transplantation, as well as for tissue engineering as seed cells. HOCs can be widely used for improving clinical treatment of liver diseases. OBJECTIVE: To establish adult Wistar rat models of HOC proliferation, to perform/n vitro isolation and culture of HOCs, and to study the possibility of induction and differentiation of HOCs into hepatucytes. DESIGN: Observational study. SETTING: Institute of Gastroenterology, Nanfang Hospital, Southern Medical University. MATERIALS: Experiments were performed at the Laboratory of Institute of Gastroenterology of Nanfang Hospital from December 2003 to February 2006. Thirty-six healthy male Wistar rats aged 3-4 months (150-200 g) were provided by Experimental Animal Center of Southern Medical University. METHODS: Male Wistar rats were orally fed with ethionine received two-thirds partial hepatectomy (2/3 PH). HOCs were harvested and purified by two-steps perfusion and Percoll density gradient centrifugation, and then cultured in vitro and induced with hepatocyte growth factor (HGF), oncostatin M (OSM) and fibroblast growth factor-4 (FGF4). MAIN OUTCOME MEASURES: Identification and differentiation of HOCs. RESULTS: The concentration of HOCs was about 1.34×108 L-1 in each rat model after in vitro isolation. These cells were round, oval or polygon, about 1/6 1/3 the size of normal hepatocytes. The nucleus-cytoplasm ratio was relatively large. After 2 weeks, clone-like proliferation of HOCs could be observed. Laser scanning confocal microscopy indicated positive expression of stem cells markers Thy-1 and C-kit in cytoplasm and membrane of HOCs. Immunocytochemistry demonstrated positive stem cells marker alpha fetoprotein (AFP) in cytoplasm of HOCs. HOCs can stably passage and its shape gradually changed after inducing with HGF, OSM and FGF4. HOC volume became larger and HOCs lost their ability of sticking to the wall of culture flask. Apparent positive stain of cytoplasm albumin (Alb) was detected 14 days after induction, and the positive ratio increased along with the extension of inducing duration. Results of cytochemistry indicated a brown or black deposit after glucose-6-phosphotase (G-6-P) staining and red particles after periodic acid-Schiff (PAS) staining. CONCLUSION: Adult Wistar rat models of HOC proliferation are replicated by ethionine feeding combined with 2/3 PH. HOCs can be obtained through collagenase perfusion and Percoll density gradient centrifugation. Rat HOCs can be passaged and cultured in vitro. Under a certain condition, HOCs can be induced and differentiated into hepatocytes.

Objectives:To systematically evaluate the clinical efficacies of unilateral biportal endoscopic lumbar interbody fusion(ULIF)and minimally invasive transforaminal lumbar interbody fusion(MIS-TLIF)in the treatment of lumbar degenerative diseases(LDD).Methods:Clinical controlled studies on ULIF and MIS-TLIF in the treatment of LDD were systematically retrieved from Chinese and English databases,including CNKI,VIP,WanFang,SinoMed,PubMed,Cochrane Library,Embase,and Web of Science.The retrieval time limit was from the establishment of the database to September 2023.The quality of the included studies was evaluated by the Newcastle-Ottawa scale(NOS).The indexes of operation time,surgical bleeding,hospitalization time,visual analog scale(VAS),Oswestry disability index(ODI),incidence of complications,disc height,and fusion rate were extracted,and Meta-analysis was performed by RevMan 5.4.1 software.Results:A total of 11 studies were included,all of which were cohort studies,and all of which were evaluated as medium-high quality by NOS.There were 800 patients,including 380 in the ULIF group and 420 in the MIS-TLIF group.The results of Meta analysis showed that the hospitalization time[WMD=-0.75,95％CI(-1.33,-0.17)],low back pain VAS(1-3 months after operation)[MD=-0.43,95％CI(-0.70,-0.15)],low back pain VAS(final follow-up＞l year)[MD=-0.09,95％CI(-0.18,-0.00)],ODI(1-3 months after operation)[MD=-1.37,95％CI(-2.46,-0.28)],and intraoperative bleeding[MD=-78.72,95％CI(-113.20,-44.23)]in the ULIF group were better than those in the MIS-TLIF group.The operation time[MD=30.28,95％CI(13.86,46.71)]in the MIS-TLIF group was better than that in the ULIF group.There were no significant differences in leg pain VAS(1-3 months after operation)[MD=-0.12,95％CI(-0.30,0.06)],leg pain VAS(final follow-up＞1 year)[MD=-0.04,95％CI(-0.15,0.07)],ODI(final follow-up＞1 year)[MD=-0.46,95％CI(-1.02,0.11)],lumbar lordosis angle[MD=0.39,95％CI(-1.12,1.90)],disc height[MD=0.03,95％CI(-0.24,0.30)],fusion rate[MD=0.97,95％CI(0.92,1.03)]and complication rate[MD=0.82,95％CI(0.45,1.48)].Conclusions:Compared with MIS-TLIF,ULIF has advantages in improving low back pain symptoms and early recovery of function,reducing intraoperative blood loss,shortening hospital stay,which is less in surgical trauma and faster in recovery.There is no significant difference in long-term efficacy,complications,and fusion rate between the two methods.