BACKGROUND: Autologous cancellous bone graft remains the most effective grafting material for bone defects because it provides the three elements required for bone regeneration: osteoconduction, osteoinduction, and osteogenic cell. OBJECTIVE: To determine the indications for a cancellous bone like nano-hydroxyapatite/collagen (nano-HA/CO) composite for treatment of osteonecrosis of the femoral head (ONFH). DESIGN, TIME AND SETTING: A randomized controlled animal study was performed at Guangdong Medical Laboratory Animal Center from May to August 2007. MATERIALS: Ten New-zealand rabbits, weighing 1.5-2.0 kg, were prepared into models of ONFH by injection of liquid nitrogen. METHODS: Ten rabbits were randomly, evenly divided into 2 groups: nano-HA/CO composites group, insertion of nano-HA/CO bone substitutes into bone defects, and control group, without any implantation. MAIN OUTCOME MEASURES: The healing processes were assessed with macroscopic examination, X-ray photography and histological examination at days 7 and 14 after surgery. RESULTS: In the nano-HA/CO composites group, osteonecrosis was halted, holes were repaired, and nano-HA/CO bone substitute was gradually degraded and absorbed; but in the control group, osteonecrosis was deteriorated and holes were not repaired, remained the same drilled at the beginning. CONCLUSION: These nano-HA/CO composites can not only replace autologous cancellous bone, but also can halt the progress of osteonecrosis insulted by liquid nitrogen. Experimental results show potent alternative of this nano-HA/CO composites in treatment of ONFH in stage II and earlier stage.

BACKGROUND: A nano-artificial bone imitating cancellous bone has been developed. It is necessary to perform a series of animal experiments regarding this artificial bone prior to clinical trials for providing technical information.OBJECTIVE: To evaluate the biodegradability, osteoconductivity, and osteoinductivity of nano-hydroxyapatite/collagen (nano-HA/CO) composites imitating cancellous bone.DESIGN, TIME AND SETTING: A randomized controlled animal experiment was performed at the Guangdong Medical Laboratory Animal Center between March and June 2007.MATERIALS: The HA powder was synthesized by a co-precipitation reaction. The obtained HA powder was added into collagen solution at a certain ratio under vigorous stirring. The nano-HA/CO composites were frozen-dried to obtain nano-artificial bone. Fifteen New Zealand rabbits were randomly divided into 3 groups, with 5 rats per group: blank control, coral-HA, and nano-HA/CO.METHODS: Following local anesthesia, 10 mm bone defect was made on the right ulnas in all rabbits. HA coral and Nano-HA/CO bone composites were inserted into the defects in the HA and nano-HA/CO groups, respectively. The blank control group received no any implantation. At 30 and 60 days following surgery, biocompatibility and osteoinductivity of cancellous bone resembling nano-HA/CO bone substitute were assessed by macroscopic examination, scanning electron microscopy, X-ray photography, and histological examination after implantation in vivo.MAIN OUTCOME MEASURES: Ultrastructure and degradation condition of nano-HA/CO bone substitute, postoperative wound healing, and osteo-regeneration in defect region.RESULTS: The nano-HA/CO bone composite possessed interconnected porosity and pore size resembling cancellous bone, which benefits in-growth of osteoblasts and blood vessels. At 30 days following surgery, the nano-HA/CO group exhibited that osteoblasts spread around, and ossification occurred in almost all newly formed bone area. At 60 days following surgery, the coral-HA group showed that only connective tissue regenerated without bone tissue regeneration and degradation of grafts.CONCLUSION: This nano-HA/CO bone composite shows great promise in repairing massive bone defect in stead of autograft.

Objective To observe the outcome of an absorbable bioactive bone-inducing material for the treatment of osteonecrosis of the femoral head (ONFH).Methods Thirty rabbits were randomly,evenly divided into three groups,experience group with bioactive bone-inducing material planted into bone collapse,control group 1 with oral ShengMaiJiaoNang and control group 2 with no implantation in the bone necrosis.Results In experiment group,bone necrosis was halted and the collapse was repaired.Meanwhile,cancellous bone and cortical bone were regenerated,necrotic bone was basically healed,and bioactive bone-inducing material was gradually degraded and absorbed.In control group 1,part of the bone marrow vascular was repaired and regenerated,and a little new bone grew,which delayed the process of necrosis.In control group 2,there was no bone tissue regeneration in the bone collapse and further deterioration was observed.Conclusions The bioactive bone-inducing material can not only replace autologous cancellous bone,but also halt the progress of osteonecrosis,which may become an alternative treatment for the stage Ⅱ and early stage of ONFH.

OBJECTIVETo study the gene expression profiles of human bone marrow derived mesenchymal stem cells and tendon cells.

METHODSTotal RNA extracted from human bone marrow derived mesenchymal stem cells and tendon cells underwent reverse transcription, and the products were labeled with alpha-(32)P dCTP. The cDNA probes of total RNA were hybridized to cDNA microarray with 1176 genes, and then the signals were analyzed by Atlas Image analysis software Version 1.01a.

RESULTSFifteen genes associated with cell proliferation and signal transduction were up-regulated, and one gene that takes part in cell-to-cell adhesion was down-regulated in tendon cells.

CONCLUSIONThe 15 up-regulated and one down-regulated genes may be beneficial to the orientational differentiation of mesenchymal stem cells into tendon cells.

Bone Marrow Cells ; Gene Expression Profiling ; Humans ; Mesoderm ; cytology ; Stem Cells ; Tendons ; cytology

Objective:To explore the characteristics of T lymphocyte subsets and cytokines in hyperlipidemia-induced acute pancreatitis (HLAP) and its prognostic value.Methods:This study included 184 patients with acute pancreatitis (AP) admitted to the First Affiliated Hospital of Xiamen University from January 2018 to May 2021. Based on disease etiology, there were 92 HLAP cases and 92 non-hyperlipidemia-induced AP (NHLAP) cases. Stratified by disease severity according to 2012 Atlanta classification criteria, the patients were divided into the severe subgroup (SAP) and non-severe subgroup (NSAP). Peripheral venous blood samples were taken from all patients on day 1, 3, and 5 after admission. T lymphocyte subsets were determined by flow cytometry, and cytokines were detected by flow fluorometry. The number of CD4 +% and CD8 +% and the expression of cytokines were compared by Student’s t test or Mann-Whitney U analysis. Logistic regression analyses were performed to identify risk factors for severe AP, and a receiver operating characteristic (ROC) curve was constructed to predict severe AP. Statistical significance was taken as P<0.05. Results:Compared with the NHLAP group, patients in the HLAP group had lower CD4 +%, while higher levels of IL-2 on day 1 ( P<0.05), and had also lower CD4 +%, while higher levels of IL-4, IL-6, and IL-10 on day 3 ( P<0.05). Furthermore, IL-6 and IL-10 levels of the HLAP group were significantly increased compared to the NHLAP group on day 5 ( P<0.05). IL-10 levels in the SAP subgroup were significantly higher than those in the NSAP subgroup on day 1 ( P<0.05). Compared with the NSAP subgroup, the SAP subgroup had elevated levels of IL-2, IL-4, IL-6, IL-10 and IFN-γ on day 3 (all P<0.05), and had lower CD4 +%, while increased levels of IL-6 and IL-10 on day 5 (all P<0.05). Multivariate Logistic regression analysis showed that IL-10 was an immune indicator of independent risk factor for severe AP in the HLAP group on day 1 ( OR=1.139, 95% CI: 1.038-1.251, P<0.05). Finally, ROC analysis showed that the area under the curve of IL-10 to assess HLAP with severe AP was 0.772, and the best cut-off value for predicting severe AP was 5.6 pg/mL, with a sensitivity of 83.3% and a specificity of 68.8%. Conclusions:Changes of CD4 +% and cytokines are different between the HLAP and NHLAP groups. IL-10 can be used as a predictor of early disease severity in patients with HLAP.