To investigate effect of the transplantation of mesenchymal stem cells (MSCs) in combination with nerve growth factor (NGF) on the repair of spinal cord injury (SCI) in adult rats, spinal cord of adult rats (n= 32) was injured by using the modified Allen's method. One week after the injury, the injured cords were injected with Dubecco-modified Eagles medium (DMEM, Group I), MSCs (Group II), NGF (Group III), and MSCs plus NGF (Group IV). One month and two months after the injury, rats were sacrificed and their injured cord tissues were sectioned for the identification of the transplanted cells. The axonal regeneration and the differentiation of MSCs were examined by immunocytochemical staining. At the same time, rats were subjected to behavioral tests by using the open-field BBB scoring system. Immunocytochemical staining showed that axonal regeneration and the transplanted cells partially expressed neuron-specific nuclear protein (NeuN) and glial fibrillary acidic protein (GFAP). At the same time, significant improvement in BBB locomotor rating scale (P<0. 05) were observed in the treatment group. More importantly, further functional improvement were noted in the combined treatment group. MSCs could differentiate into neurons and astrocytes. MSCs and NGF can promote axonal regeneration and improve functional recovery. There might exist a synergistic effect between MSCs and NGF.

Objective To test the releasing property of a self-developed plastic drug delivery implant of anti-infective nano-hydroxyapatite(nano-HA)so as to provide a new local drug delivery system(LDDS)for treatment of osteomyelitis.Methods The nano-HA was used as the core carrier to load gentamicin(GM).It was coated with poly hydroxybutyrate-co-hydroxyvalerate /polyethylene glycol(PHBV/PEG)to prepare the nano-HA-PHBV/PEG-GM microspheres which were mixed with the fibrin sealant(FS)to develop a plastic implant.Then its antibacte rial and in vitro releasing properties were investigated.Results The plastic LDDS implant was found to have a fine drug delivery capability.The bacterial growth inhibition zone was found around the LDDS for 56 days in the antibacterial test.Three samples were soaked with liquid of PBS(phosphate buffered saline).The titer of GM released within the first day was 154.3 ?g/mL,and then the releasing maintained a slow level in the following days.After 49 days'releasing,the titer was 6.9 ?g/mL which was still higher than the MIC(2 ?g/mL)(minima l inhibitory concentration)of GM.Conclusion The plastic LDDS has a fine in vitro releasing property and may have a widespread application in treatment of osteomyelitis.

[Objective]To investigate the relationship between degeneration of cartilage and the expressions of Matrix Metalloproteinase 7(MMP-7),Matrix Metalloproteinase 9(MMP-9),Matrix Metalloproteinase 13(MMP-13)and Tissue Inhibitor of Matrix Metalloproteinase 1(TIMP-1)in osteoarthritis.[Method]The histological changes of cartilages by hematoxyllin-eosin staining and immunohistochemical expression of Matrix Metalloproteinase 7(MMP-7),Matrix Metalloproteinase 9(MMP-9),Matrix Metalloproteinase 13(MMP-13)and Tissue Inhibitor of Matrix Metalloproteinase 1(TIMP-1)in osteoarthritis.were studied in 20 osteoarthritis cases and 2 normal controls.All data were statistically analyzed by Mann-Whitney U test and correlation analysis.[Result]The osteoarthritis cartilage underwent fibroplasias and tearing.The quantity of chondrocyte increased and the clustered and hypertrophic cells came into being.Little immunostaining of MMP-7 and MMP-13 was observed in normal cartilage,while their expressions increased in degenerated cartilage(P0.05),superficial layer of the moderate and end-stage osteoarthritis.However,it significantly increased in deep layer(P

Purpose: To retrospectively analyse the characteristics of diagnosis and operative treatment of 66 cases of scwannoma in the spinal canal. Methods: Sixty-six cases, 27 of the cervical region, 13 the thoracic and 26 of the lumbar and sacral regions were treated from 1983 to 1996. Clinical manifestation and types, and results of spinal radiography, myelography, CT scannig, MR imaging, operative treatment were separately described. Results: All of the 66 cases obtained timely and accurate diagnosis and treatment. The tumors in 60 patients were completely resected; and in remaining 6 patients subtotal excision was performed. The duration of follow-up averaged two years and eleven months and excellent and good results were achieved in 90.9% of the patients. Conclusions: 1) Schwannoma in the spinal canal is not uncommon; four in this series are malignant or with malignant tendency. 2) The forms of the tumor are with lots of variations. 3)An approximate position of the lesion can be determined by clinical neurological examination. Accurate diagnosis can be made by a procedure combining clinical and imaging examinations, operative exploration and pathological examination. 4) Total resection of the tumor may result in good restoration although it is sometimes difficult and risky.

To investigate effect of the transplantation of mesenchymal stem cells (MSCs) in combination with nerve growth factor (NGF) on the repair of spinal cord injury (SCI) in adult rats, spinal cord of adult rats (n= 32) was injured by using the modified Allen' s method. One week after the injury, the injured cords were injected with Dubecco-modified Eagles medium (DMEM , Group Ⅰ), MSCs (Group Ⅱ), NGF (Group Ⅲ), and MSCs plus NGF (Group Ⅳ). One month and two months after the injury, rats were sacrificed and their injured cord tissues were sectioned for the identification of the transplanted cells. The axonal regeneration and the differentiation of MSCs were examined by immunocytochemical staining. At the same time, rats were subjected to behavioral tests by using the open-field BBB scoring system. Immunocytochemical staining showed that axonal regeneration and the transplanted cells partially expressed neuron-specific nuclear protein (NeuN) and glial fibrillary acidic protein (GFAP). At the same time, significant improvement in BBB locomotor rating scale (P＜0.05) were observed in the treatment group. More importantly, further functional improvement were noted in the combined treatment group. MSCs could differentiate into neurons and astrocytes. MSCs and NGF can promote axonal regeneration and improve functional recovery. There might exist a synergistic effect between MSCs and NGF.

Matrix metalloproteinase-2 (MMP-2) level and the ERK1/2 signal pathway are dependent factors for the growth and metastasis of cancer. However, the impact of MMP-2 in combination with ERK1/2 in tumor patients with drug resistance is unknown. To determine the relationship between MMP-2 and the ERK1/2 signal pathway, we established an adriamycin (ADM)-induced MG-63 (ADM-MG-63) cell line. With the increase of the ERK1/2 pathway blocker PD98059, we detected the expression levels of MMP-2 and p-ERK1/2 by Western blot in ADM-MG-63 cells. In ADM-MG-63 cells transfected with MMP-2-siRNA, the expression of ERK1/2 was detected for understanding the function of the ERK1/2 signal pathway. Three siRNAs for MMP-2 (MMP-2-siRNA) were designed, and the optimal one was selected and tested at different time points of 24, 48 and 72 h. Under an ADM-induced condition, ADM-MG-63 cells were finally stable living in the medium of ADM (200 ng/mL). PD98059 could effectively suppress the expression levels of p-ERK1/2 and MMP-2. When the MMP-2 was silenced by using MMP-2-siRNA, the expression of p-ERK1/2 was enhanced. It is concluded that MMP-2 may be involved in ADM resistance dependent on ERK1/2 signal pathway, suggesting interference in ERK1/2 may be a new method of targeted therapy for tumor resistance.

BACKGROUND: The precartilaginous stern cells are limited regarding in vitro proliferative capacity, but the immortalized cell lines can provide a large number of stable immortalized cells, and simian virus 40 large T antigen gene (SV40Tag) is one of gene fragments which are commonly used and effective in vitro immortalized ceils. OBJECTIVE: To construct human immortalized precartilaginous stem cells (IPSCs) using human precartilaginous stem calls induced by SV40LTAg gane. METHODS: The human immortalized precartilaginous stem calls were isolated from aborted fetus and purified with enzyme digestion and immunomagnetic beads screening method. By using liposome-mediated gene transfection technology, plasmid pCMVSV40T/PUR containing SV40Tag was transfected in primary embryonic precartilaginous stem cells, while non-transfected cells sewed as negative controls. Positive clones were cultured to observe the cell morphology and the passage recovery, to calculate cell survival rata and population doubling time, to drew call growth curve. Immunofluorescence cytochemistry was used to detect the expression of IPSCs fibroblast growth factor receptor 3, the expressions of SV40Tag and fibroblast growth factor receptor 3 in the human precartilaginous stem cells were determined by RT-PCR. RESULTS AND CONCLUSION: Morphology of human IPSCs seemed coincidence with primary human precartilaginous stem cells. The survival rate of human IPSCs was not influenced by subculture, freezing and recovery, but the survival rate was descended in the human precartilaginous stem cells at the 6~(th) and 10~(th) passages (P < 0.01). Compared with cells at the 6~(th) and 10~(th) passages, the proliferation of human IPSCs was greater, with short population doubling time and high growth rate (P < 0.01). The immunofluorescence showed that fibroblast growth factor receptor 3 was positive in human IPSCs at the second passage, and the RT-PCR results of fibroblast growth factor receptor 3 revealed a specific amplification band at 400 bp,.while that of SV40Tag revealed at 560 bp. No band was seen in the primary cells. It is indicated that SV40Tag human IPSCs can be constructed successfully using immunomagnatic bead screening technology and liposome transfection technique.

Objective To investigate the changes of excitatory amino acids (EAAs) of cerebrospinalfluid (CSF) in patients with delayed encephalopathy after acute carbon monoxide poisoning(DEACMP).Method The EAAs levels of CSF including glutamate (Glu) and aspartate (Asp) in 24 patients with DEACMP and 20 controls with migraine were measured by high performance liquid chromatography( HPLC ).Results Glu and Asp levels in patients with DEACMP were significantly higher than those of the controls [(3.76 ± 1.52) μmol/L vs ( 1.55 ± 1.03 ) μmol/L, (0.73 ± 0.44) μmol/L vs (0.38 ± 0.33 ) μmol/L, P all <0.01]. Glu and Asp levels in moderate and severe DEACMP patients were higher than those in mild DEACMP patients. Conclusion It suggests that EAAs participated in the pathogenesis of DEACMP. The Glu and Asp levels in CSF may be regarded as indicator of DEACMP.

BACKGROUND: Supraspinatus tendon injury is common in rotator cuff injury, the repair difficulty of which is reconstructing the bone-tendon interface. Currently, there are no effective therapeutics and suitable experimental animal models.OBJECTIVE: To establish rabbit rotator cuff injury prosthetic experimental animal model and to observe the effect of continuous passive motion (CPM) on early healing of rabbit rotator cuff bone-tendon interface by MRI, which can provide guidance for preparing an optimal rehabilitation strategy after rotator cuff injury.METHODS: Sixteen male New Zealand rabbits, aged 8 months, were received a rotator cuff acute injury and reconstructing insertion of supraspinatus tendon on greater tuberosity of humerus. The rabbits were randomly divided into cage activity group (n=4) and CPM group (n=12). At 2 days after operation, rabbits were treated by rabbit shoulder joint continuous passive motion apparatus of 75°～75° flexion-extension with various CPM speeds[2 (°)/s, 4 (°)/s, and 10 (°)/s)]. General state and MRI changes of rabbit rotator cuff bone-tendon interface was observed prior to and at weeks 1,2, and 4 after operation.RESULTS AND CONCLUSION: Gross observation showed that the incisions healed very well at 2 weeks after operation. There was no infection, haematoma or disruption after removing the suture. Compared to the cage activity group, the tendon-bone interface of CPM group heeled better at weeks 1, 2 and 4, especially at the speed of 4°/s with 75°-75° flexion-extension. Results demonstrated that this animal model can be satisfied to experimental study. From the following day after operation, various CPM speeds can accelerate the healing of tendon-bone interface, and the optimal speed of CPM was 4 (°)/s.

This study examined the construction of eukaryotic expression plasmid of human transforming growth factor-β3 (hTGF-β3) and its inducing effect on the differentiation of precartilaginous stem cells (PSCs) into chondroblasts. hTGF-β3 gene was amplified by using polymerase chain reaction (PCR) and then inserted into the eukaryotic expression plasmid pcDNA3.1 to construct the eukaryotic expression plasmid pcDNA3.1(+)-hTGF-β3. Rat PSCs were isolated and purified by employing an immunomagnetic cell sorting system. pcDNA3.1(+)-hTGF-β3 was transfected into purified PSCs with the use of linear polyamines. The expression of TGF-β3 and cartilage-specific extracellular matrix (ECM) components was detected after transfection by real-time quantitative PCR, ELISA, immunochemistry and Western blotting, respectively. The results showed that the eukaryotic expression plasmid pcDNA3.1(+)-hTGF-β3 was successfully established as identified by enzyme digestion and DNA sequencing. Real-time quantitative PCR and ELISA revealed that hTGF-β3 was strongly expressed in pcDNA3.1(+)-hTGF-β3-transfected PSCs. Real-time quantitative PCR, immunochemistry and Western blotting showed that the cartilage-specific ECM markers, i.e., cartilage oligomeric matrix protein (COMP), Aggrecan, collagen type X and II were intensely expressed in the pcDNA3.1(+)-hTGF-β3-transfected cells. It was concluded that hTGF-β3 could be stably expressed in pcDNA3.1(+)-hTGF-β3-transfected PSCs and induce the differentiation of PSCs into chondroblasts.