BACKGROUND: Studies showed cellular adhesion molecule and neurotrophic factor secreted from olfactory ensheathing cells (OECs) could protect the spinal neurons and promote the regeneration of spinal axon. OBJECTIVE: To compare the competence to repair spinal cord injury between olfactory mucosa OECs and olfactory bulb OECs. DESIGN, TIME AND SETTING: Randomized control animal experiment was performed in the central laboratory of Xidian Group Hospital between June 2007 and June 2008. MATERIALS: Twelve male SD rats were randomized selected and divided into experiment group (n=6, 23 months old) and control group (n=6, 3 months old). They were used for in vitro culture and purification of OECs; other 30 SD rats were randomized into three groups of 10 rats each: neonatal rat olfactory bulb OECs transplantation group, normal olfactory mucosa OECs transplantation group and blank control group.METHODS: Spinal cord injury models were produced in 30 rats, which were transplanted with the neonatal rat or SD rat OECs cultured in vitro. No transplant was given in the control group. MAIN OUTCOME MEASURES: At 4 and 8 weeks postoperation, the Basso, Beattie, Bresnahan (BBB) score for nerve function, the evoked potential of legs and the histopathological diversify of injured spinal cord. RESULTS: Seven rats died dudng the experiment process, and the death rate was similar between groups. At 4 and 8 weeks postoperation, there was no significant difference in the BBB scores between neonatal rat olfactory bulb OECs transplantation group and normal olfactory mucosa OECs transplantation group (P > 0.05), which were both significantly higher than blank control group (P < 0.001); the BBB scores in two transplantation groups were higher at 8 weeks than at 4 weeks (P < 0.01 ). At 4 weeks postoperaUon, no animal was shown to elicit motion evoked potential, but it was present in two transplantation groups at 8 weeks, with no significant difference between two groups (P > 0.05). The blank control group had still no motion evoked potential (P < 0.001 ). At 8 weeks postoperation, more cell infiltrations were found in the injured spinal cord of two transplantation groups, while few in the control group.CONCLUSION: Both OECs dissociated from olfactory bulb and olfactory mucosa have the same ability to repair the injured spinal cord, and their effect is similar.

In order to investigate the protective effect of hypoxic preconditioning on the cerebral ischemia-reperfusion injury, the expression of Bcl-2 and Bax was detected by using immunohistochemical staining after 3 h cerebral ischemia followed by 1, 6, 12, 24 and 48 h reperfusion respectively in rats treated with or without hypoxic preconditioning before cerebral ischemia. In addition,the apoptosis of neural cells and the behavioral scores for neurological functions recovery were evaluated by TUNEL staining and "crawvling method", respectively. Compared with control group (cerebral ischemia-reperfusion without hypoxic preconditioning), the expression of Bcl-2 was significantly increased, but that of Bax decreased in the hypoxic preconditioning group (cerebral ischemiareperfusion with hypoxic preconditioning), both P＜0. 05. The pre-treatment with hypoxic preconditioning could reduce the apoptosis of neural cells and promote the neurological function recovery as compared to control group. It was suggested that hypoxic preconditioning may have protective effects on the cerebral ischemia-reperfusion injury by inhibiting the apoptosis of neural cells, increase the expression of Bcl-2 and decrease the expression of Bax.

[Objective To explore the effect of problem-based learning(PBL) in biochemistry teaching in medical college. Methods Totally 128 students(2011 grade) of medical laboratory major were derived into experiment group(n=64)and control group(n=64). Lecture-based learning(LBL) was used in control group and PBL was used in experiment group.In control group,teachers did teaching design according to the needs of curriculum standards,employed multimedia courseware,explained the basic content of each chapter,class exercises and homework after class. In experimental group,PBL was conducted through establishing biochemistry teaching website based on school's teaching platform. Teach-ing process in experiment group included:grouping-selecting appropriate cases-consulting data-group discussing-summarizing by teachers. Theory test was carried out after the course and questionnaire was conducted for students in experiment group . Data were analyzed using the independent sample t test . Results Average test scores were higher in PBL group than in traditional group,with statistically signif-icant differences[(83.15±11.87)vs. (76.15±12.48)]. Questionnaire survey showed that more than 90.0%students in experiment group were interested in the PBL teaching method and thought that the PBL teach-ing method can enhance the enthu-siasm of learning, independent learning ability and comprehensive analysis ability. Conclusions PBL teaching method can improve the quality and the effect of biochemi-stry teaching and culture students' comprehensive ability. It is worthy of further study and popularization.

Objective To investigate the perihematomal changes of hyperacute parenchymal hematomas and the clinical value by MRI. Methods Multi-sequence MRI was performed on 4 hematomas in vitro and on 15 pigs with lobar intracerebral hemorrhage (ICH) for about 30～60 min and 3 h respectively. The integrity of blood-brain barrier (BBB) in ICH pigs was assessed by electron microscopy and Evan's blue dye technique. MR scanning was performed on 2 ICH patients proved by CT for 4 and 9 h after onsets. Results FLAIR and T 2-weighted images showed hyperintensity signal around the hematomas in vitro and in pigs with ICH within 1 h, and more obviously at 3 h. When the gelose cavity was cut, plasma was seen around the clot. The perihematomal ADC values of the pigs increased both within 1 and at 3 h after ICH. However, the BBB was intact at 3 h, which was proved by electron microscopy and Evan's blue dye technique. Water-like intensity signal was observed around the hematomas in two patients with acute ICH. Conclusion The perihematomal changes of hyperacute ICH observed on MRI are resulted from the blood clot contraction and the serum formation and extravasation, but not real cerebral edema.

Objective To explore the effect of low constant direct current (LCDC) in the medullary cavity on repairing of rabbit radial defect as to evaluate its clinical value. Methods DBX was put into the segmental osteoperiosteum defect of rabbit bilateral radius. The rabbits were divided into 2 groups: group A (subject group) with the defects stimulated by LCDC and group B (control group) with the defects left untreated. In week 2,5 and 9, 4 animals from each group were put into death, and the radius was taken for study using photograph, electron microscope, histological & morphologic technique, and the contents of the Calcium (Ca) and ALP were determined. Results Compared with group B, the healing of group A was better. The contents of Ca and ALP increased obviously in week 2 (P

Objective To assess the feasibility of ultrasmall superparamagnetic iron oxide (USPIO)-enhanced magnetic resonance imaging (MRI) for monitoring the phagocytic activity in the brain tissue of rats following focal cerebral ischemia-reperfusion (IR) injury. Methods Forty male SD rats were randomized into 5 groups, namely 2, 3, 5-triphenyltetrazolium chloride (TTC) staining group (n=4), sham-operated group (n=6), and 3 cerebral IR injury groups with reperfusion time of 24, 48, and 72 h (n=10). USPIO was intravenously injected after focal cerebral IR injury, and MRI was performed at 24, 48, and 72 h after the reperfusion. The rats were sacrificed at 24, 48 and 72 h, and frozen sections of the local brain tissues were prepared to observe the cell death with HE staining, iron particle distribution with Prussian blue staining and the activity of the macrophages by CD68 immunohistochemical staining and immunofluorescent labeling. Results The ischemic lesions were identified as hyperintense area on T2-weighted images (T2WI) after middle cerebral artery occlusion (MCAO). The accumulation of USPIO appeared as hyperintense areas on T1WI and hypointense area on T2WI. The maximum signal change was observed at 24 h on T1WI (1.60±0.28) and at 48 h on T2WI (0.92±0.17) (P<0.05), and at each of the time points, the enhancement was significantly greater on T1WI than on T2WI (P<0.05). No obvious signal changes were found in the control group. Prussian blue staining detected iron oxide particles in both the peripherals of the ischcmic region and the necrotic area. A similar distribution pattern of the macrophagcs or activated microglia was found by CD68 immunohistochemistry and immunofluorescent labeling. Conclusion USPIO-cnhanced MRI allows dynamic monitoring of the inflammatory reaction in the local brain tissues aftcr focal cerebral IR injury.

Methods: Thirty patients with PDVO of the lumbar or thoracic spine treated with transforaminal interbody debridement and fusion (TIDF) with AIBG between March 2014 and May 2022 were reviewed (AIBG group). For comparative analysis, 28 PDVO patients who underwent TIDF without AIBG between January 2009 and June 2011 were enrolled (non-AIBG group). The minimum follow-up duration was 2 years. Clinical characteristics and surgical indications were comparable in the two groups. C-reactive protein (CRP) levels and the postoperative antibiotics course were compared between the two groups. Results: Surgical treatment for PDVO resulted in clinical improvement and adequate infection control. Despite the shorter postoperative intravenous antibiotic duration (mean: 19.0 days vs. 39.8 days), the AIBG group had significantly lower CRP levels at postoperative 4 and 6 weeks. The mean Visual Analog Scale pain scores improved from 7.3 preoperatively to 2.2 at 6 weeks postoperatively. The average angle correction at the last follow-up was 7.9°. Conclusions TIDF with AIBG for PDVO can achieve local infection control with a faster reduction in CRP levels, leading to a shorter antibiotic duration.

Methods: Thirty patients with PDVO of the lumbar or thoracic spine treated with transforaminal interbody debridement and fusion (TIDF) with AIBG between March 2014 and May 2022 were reviewed (AIBG group). For comparative analysis, 28 PDVO patients who underwent TIDF without AIBG between January 2009 and June 2011 were enrolled (non-AIBG group). The minimum follow-up duration was 2 years. Clinical characteristics and surgical indications were comparable in the two groups. C-reactive protein (CRP) levels and the postoperative antibiotics course were compared between the two groups. Results: Surgical treatment for PDVO resulted in clinical improvement and adequate infection control. Despite the shorter postoperative intravenous antibiotic duration (mean: 19.0 days vs. 39.8 days), the AIBG group had significantly lower CRP levels at postoperative 4 and 6 weeks. The mean Visual Analog Scale pain scores improved from 7.3 preoperatively to 2.2 at 6 weeks postoperatively. The average angle correction at the last follow-up was 7.9°. Conclusions TIDF with AIBG for PDVO can achieve local infection control with a faster reduction in CRP levels, leading to a shorter antibiotic duration.

Methods: Thirty patients with PDVO of the lumbar or thoracic spine treated with transforaminal interbody debridement and fusion (TIDF) with AIBG between March 2014 and May 2022 were reviewed (AIBG group). For comparative analysis, 28 PDVO patients who underwent TIDF without AIBG between January 2009 and June 2011 were enrolled (non-AIBG group). The minimum follow-up duration was 2 years. Clinical characteristics and surgical indications were comparable in the two groups. C-reactive protein (CRP) levels and the postoperative antibiotics course were compared between the two groups. Results: Surgical treatment for PDVO resulted in clinical improvement and adequate infection control. Despite the shorter postoperative intravenous antibiotic duration (mean: 19.0 days vs. 39.8 days), the AIBG group had significantly lower CRP levels at postoperative 4 and 6 weeks. The mean Visual Analog Scale pain scores improved from 7.3 preoperatively to 2.2 at 6 weeks postoperatively. The average angle correction at the last follow-up was 7.9°. Conclusions TIDF with AIBG for PDVO can achieve local infection control with a faster reduction in CRP levels, leading to a shorter antibiotic duration.

Objective To investigate the feasibility of ultrasmall superparamagnetic iron oxide- enhanced(USPIO)-enhanced MR imaging for monitoring synovitis of antigen-induced arthritis in rabbit model and explore the optimal MR imaging sequences.Methods Nine female white rabbits with antigen(0.5 ml mBSA,2 mg/ml)induced arthritis of the right knees were used in the study.The left knees of these rabbits and both knees of another 3 rabbits served as the control.Nine to 28 days(mean 21.3 d)after successful model induction,all knees were imaged before and 24 h after intravenously injection of USPIO (0.3 ml/kg),among which 2 rabbits were also imaged at 48 and 72 h after administration of USPIO respectively.The MR protocol included spin-echo(SE) T_1WI,fast spin-echo(FSE)T_2WI,gradient echo (GRE)T_2~* WI and short tau inversion recovery(STIR).Images were analyzed quantitatively and qualitatively based on signal characteristics and patterns of the synovium.Paired t-test was used for the analysis of the signal intensity of inflammatory synovial membrane before and 24 h after injection of USPIO. MR findings were correlated with histopathology.Results Arthritis was successfully induced in all 9 right knees with intraarticular injection of mBSA.Pathological examination revealed hyperplasia of synovium with infiltration of USPIO-loaded-macrophages.MR depicted synovial thickening(thickness 2.07?0.97 mm) and joint effusion.Synovium and joint fluid appeared as slightly hypo- or iso-intense on T_1 WI and hyper- intense on T_2 WI or T_2~* WI.Twenty four hours after USPIO injection,significant T_1 enhancement(ASNR 41.91%?27.94%),negative T_2 and T_2~* enhancement(△SNR -34.92%?11.77% and -57.24%? 16.05%)were demonstrated in the region of synovial inflammation respectively.The signal at 48 h and 72 h changed less than that at hour 24.No signs of arthritis occurred in all left knees and in all knees of the artificial model group.Conclusion Iron oxide phagocytized into macrophages can be a root cause resulted in signal change on USPIO-enhanced MR images.The gradient echo sequence should be the optimal sequence to be used in USPIO-enhanced MR imaging in antigen-induced arthritis.