Objective To explore the effects of Neurogenesin 1 (Ng1) gene on functional recovery after spinal cord injury (SCI) and its mechanism. Methods Thirty-six rats (aging 4 months, weighing 230 g and being male or female), were randomly divided into two groups: experimental group (n=18) and control group (n=18). After spinal cord contusive injury at T10 level was made in all these rats using modified Allen’s method, Ng1 recombinant plasmid and blank plasmid were transfectedinto the damaged areas of exprimental group and control group respectively by Alzet pumps. At 1 day, 1 week, 2 weeks, 3 weeks, and 4 weeks after SCI, Basso-Beattle-Bresnahan (BBB) Rating Scale was used to observe the recovery of motor function. At 1 week after injury, the expressions of Ng1 mRNA and protein in injured spinal cord were detected by RT-PCR and Western blot techniques. And at 2 and 4 weeks, double immunofluorescence and histopathologic examinations were performed to study the prol iferation of the adult endogenous neural stem cells and pathological change after SCI. Results At 1-4 weeks after SCI, the BBB scores in the exprimental group was significantly higher than that in control group (P lt; 0.05), and at 4 weeks the BBB score of the experimental group (16.80 ± 1.79) was significantly higher than that of the control group (9.60 ± 1.67), (P lt; 0.01). RTPCR and Western blot showed that the mRNA and protein expressions of Ng1 were observed in the exprimental group and no expression was seen in the control group. Histologic observation showed that the morphology of spinal cord and neurons in the exprimental group was better than that in the control group and was close to the normal tissue. The mean number of Nestin+/ BrdU+ newborn endogenous neural stem cells in the exprimental group was significantly more than that in control group (P lt; 0.05). Conclusion Ng1 gene could promote the prol iferation of endogenous neural stem cells and protect the injured neurons, which enhances the repair of the motor function after SCI.
ObjectiveTo observe the protective effect of etomidate (ET) on cultured retinal ganglion cells (RGC) with mechanical injury in vitro. MethodsNew Sprague-Dawley rat RGC was cultured in vitro and identified by double immunofluorescent labeling of Thy1.1 and microtubule associated protein 2. The cultured primary cells were randomly divided into control group, RGC scratch group, ET low dose group (1 μmol/L), ET medium dose group (5 μmol/L) and ET high dose group (10 μmol/L). The RGC mechanical injury model was established by using iris knife to culture cells in RGC scratch group and ET group with different concentration. Seven days after modeling, the RGC survival rate of each group was detected by cell count Kit 8 proliferation assay. The apoptosis rate of RGC was detected by Annexin Ⅴ/propyl iodide double staining. Single factor analysis of variance was used to compare the groups. The pairwise comparison between groups was tested by the least significant difference method. ResultsThe survival rates of RGC in RGC scratch group, ET low dose group, ET medium dose group and ET high dose group were (72.60±2.97)%, (73.73±1.14)%, (79.19±1.79)% and (83.88±0.94)%, respectively. The RGC apoptosis rates of control group, RGC scratch group, ET low dose group, ET medium dose group and ET high dose group were (5.08±0.17)%, (18.67±1.24)%, (17.96±0.74)%, (15.11± 0.56)% and (11.67±1.32)%, respectively. Comparison of RGC survival rate between groups: compared with RGC scratch group, the cell survival rate of ET low-dose group, ET medium-dose group and ET high-dose group was increased, and the difference between RGC scratch group and ET low-dose group was not statistically significant (P=0.728); the differences between RGC scratch group, ET medium dose group and ET high dose group were statistically significant (P＜0.001); the difference between ET medium dose group and ET high dose group was statistically significant (P=0.002). Comparison of apoptosis rate of RGC among groups: the apoptosis rate of RGC scratch group was significantly higher than that of control group, the difference was statistically significant (P＜0.001). Compared with RGC scratch group, the apoptosis rate of ET low-dose group, ET medium-dose group and ET high-dose group was decreased, and there was no statistical significance between RGC scratch group and ET low-dose group (P=0.869). The differences of apoptosis rate between RGC scratch group, ET medium dose group and ET high dose group were statistically significant (P＜0.05). The difference of apoptosis rate between ET medium dose group and ET high dose group was statistically significant (P=0.007). ConclusionET has neuroprotective effect on RGC cultured in vitro with mechanical injury, and the protective effect increases with the increase of ET dose in a certain range.
It is an inexorable trend that evidence-based medicine (EBM) is being adopted at clinical medicine education in the 21st century. EBM neurology has been developing with the progress of the world of evidence-based medicine and clinical neurology. New requirements have been proposed in neurology education with the development of EBM. The adoption of EBM in modern clinical education will be a great influence: promoting the further development of neurology, cultivating talented doctors, and improving the quality of treatment.
Prevention and treatment of traumatic neuroma by implanting the proximal neural stump into the muscle were studied. Sixteen SD rats were used for the experimental study. The proximal stump of the left sciatic nerve was implanted into the nearby muscle as the experiment side, whereas the proximal stump of the right sciatic nerve was left untreated as the control side. The results were assessed with histological and electrophysiological methods. The experiment demonstrated that neuroma was formed in the control side one month postoperatively, whereas in the experimental side the nerve fibers were dispersed among the muscle fibers and no definite neuroma was formed. Implantation of neural stump into muscle could prevent and treat traumatic neuroma.
Purpose To identify the expression of alternatively spliced mRNA isoforms of the NMDA-R1 in the visual cortex of strabismic cats. Methods Two pai rs of normal and strabismic cats were used．The amblyopic cats had been made monocularly esotropic (by tenotomy) at the age of weeks，resulting in behavioral am blyopia．Animals were sacrificed about 6 months by intraperitoneal administration of Nembutal．Cryostat sections of fresh，frozen central visual cortex of the ats were cut to 20 micron thickness．A series of digoxygenin-labelled oligonucle otide probes basing on the human gene sequence were used for ISH．Control probes included sense oligonucleotides and short segment probes which were adjacent to ，but did not，span the splice junctions．A computer-assisted systematic morphometric ounting procedure was used to enumerate hybridising cells． Results The number of positive cells expressing NMDA-R1 mRNA in t he strabismic amblyopic cats was decreased，notably in layer IV of visual cortex (P＜0．0001)．The pattern of isoform expression varied between normal and strabismic amblyopic cats with decreased numbers of 1-a，1- b and 1-1 isoforms and apparently increased expression of 1-3 P ＜0．0001)，whereas no significant difference was found for the 1-2 and 1-4 isoforms (P＞0．05)． Conclusion Transcriptional inhibition of NMDA-R1 mRNA and of specifie isoforms may underlie the change in receptor expression．Alternatively，preferentialloss of neurones bearing particular NMDA-R1 isoforms and compensation with a proportional increase in cells expressing other isoforms may occurr during the critical period of visual plasticity． (Chin J Ocul Fundus Dis，2000，16：71-138)
Objective To investigate the effect of carboxymethylated chitosan (CMCS) on the proliferation, cell cycle, and secretion of neurotrophic factors in cultured Schwann cells (SCs). Methods SCs were obtained from sciatic nerves of 20 Sprague Dawley rats (3-5 days old; male or female; weighing, 25-30 g) and cultured in vitro, SCs were identified and purified by immunofluorescence against S-100. The cell counting kit 8 (CCK-8) assay was used to determine the proliferation of SCs. The SCs were divided into 4 groups: 50 μg/mL CMCS (group B), 100 μg/mL CMCS (group C), 200 μg/mL CMCS (group D), and the same amount of PBS (group A) were added. The flow cytometry was used to analyze the cell cycle of SCs; the real-time quantitative PCR and Western blot analysis were used to detect the levels of never growth factor (NGF) and ciliary neurotrophic factor (CNTF) in cultured SCs induced by CMCS. Results The purity of cultured SCs was more than 90% by immunofluorescence against S-100; the CCK-8 results indicated that CMCS in concentrations of 10-1 000 μg/mL could promote the proliferation of SCs, especially in concentrations of 200 and 500 μg/mL (P lt; 0.01), but no significant difference was found between 200 and 500 μg/mL (P gt; 0.05). CMCS at a concentration of 200 μg/mL for 24 hours induced the highest proliferation, showing significant difference when compared with that at 0 hour (P lt; 0.01). The percentage of cells in phase S and the proliferation index were significantly higher in groups B, C, and D than in group A (P lt; 0.05), in groups C and D than in group B (P lt; 0.05); and there was no significant difference between group C and group D (P gt; 0.05). Real-time quantitative PCR and Western blot results showed that the levels of NGF and CNTF in groups B, C, and D were significantly higher than those in group A (P lt; 0.05), especially in group D. Conclusion CMCS can stimulate the proliferation, and induce the synthesis of neurotrophic factors in cultured SCs.
Objective To observe the serumlevel of neuron-specific enolase( NSE) in patients with pulmonary encephalopathy and its changes after treatment with mechanical ventilation. Methods Twentyone patients with pulmonary encephalopathy were enrolled. Glasgow coma scale( GCS) , serumNSE level, and arterial blood gas were evaluated at three time-points: before mechanical ventilation, after 12 hours mechanical ventilation, and the moment of consciousness. Results 18 patients recovered consciousness, and 3 patients remained in persistent coma and died. GCS and arterial blood gas improved obviously after 12 hours mechanical ventilation. Meanwhile, the serumNSE concentration decreased significantly after 12 hours mechanical ventilation [ ( 24. 54 ±6. 65) μg/L] and at the moment of consciousness [ ( 14. 19 ±2. 91) μg/L] compared with before mechanical ventilation( P lt; 0. 05, P lt; 0. 01) . Conclusion Dynamic measurment of serumNSE may be a useful biomarker for assessing the severity of cerebral injury and predicting prognosis.
Objective To discuss the feasibility of treating the brain ischemic stroke by the co-transplantation of the neural stem cells(NSCs) and the endothelial progenitor cells(EPCs). Methods The original biomedical articles concerned with the treatment of the brain ischemic therapy by the use of the NSCs and the EPCs were extensively reviewed as well as retrieved and analyzed. Results The review revealed that the NSCs and the EPCs could migrate to the injured area due to brain ischemic stroke, the environment of the local microcirculation could induce the neurogenesis and the vasculogenesis to repair the injury, and the neurogenesis and vasculogenesis could promote each other. Conclusion The co-transplantation of the NSCs and the EPCscan represent a new promising strategy formore effectively solving the two difficult problems of the neural cell loss andthe vascular obstruction caused by the brain ischemic stroke.
Objective To investigate the application of Magnetoencephalograph (MEG), Wada test combined with neuronavigation in the surgical treatment of frontal and temporal epilepsy caused by focal cortical dysplasia (FCD ). Methods The epileptogenic focus and IQ, memory and language examination were performed in 34 patients with frontal and temporal epilepsy caused by FCD. MEG and Wada test were conducted to determine the language and memory advantage hemisphere, and to clarify the scope and memory function of language function areas. Operation was guided by the Medtronic stealhealth 7 surgical navigation system (USA) to remove the FCD and protect nerve function. IQ, memory and language examination were measured 1 year after operation, and the difference was observed before and after operation. The postoperative follow-up was 23 ~ 46 months, curative effect of epilepsy was determined according to the international anti-epilepsy union Engel’s standard. Results Thirty-four patients with epilepsy (21 temporal lobe epilepsy and 13 frontal lobe epilepsy) were included in this study. The examination process of MEG and Wada test was smooth. MEG can accurately locate the position of language function area. Twenty-eight patients’ dominant hemisphere of language was on the left and 6 was on the right side. Wada test can evaluate the patient’s memory function. Twenty-three patients’ dominant hemisphere of memory was located on the left, 8 on the right and 3 on the bilateral hemisphere. Compared with the dominant hemisphere and nondominant hemisphere, the memory score was significantly different (P<0.05). Statistics showed that the verbal IQ and total IQ increased (P<0.05)1 year after operation, but there was no significant change in memory IQ and Performance IQ (P>0.05). FCD patients recovered well without language, memory and limb impairment. The curative effect of epilepsy: 15 cases of Engel’sⅠgrade, 14 cases of Engel’sⅡgrade and 5 cases of Engel’s Ⅲ grade. Conclusion MEG, Wada test combined with neuronavigation was of important value in locating and guiding the surgical resection of FCD in patients with refractory frontal and temporal epilepsy, protecting cortical function, avoiding severe postoperative complications, and improving the therapeutic effect of epilepsy.
OBJECTIVE: To investigate the changes of regeneration and conduction function for peripheral nerve after neurolysis by nerve special staining and electrophysiology. METHODS: Sixty Sprague-Dawley male rats were randomly divided into four groups(n = 15), four methods were designed on rats models of sciatic nerve compression. There were simple decompression as group A, internal neurolysis after decompression as group B, lemithason(0.5 mg/kg) injected in the epineurium after decompression as group C, and lemithason(0.5 mg/kg) injected around the epineurium after decompression and internal neurolysis as group D. Motor nerve conduction velocity(MNCV) and motor latency (Lan) were monitored at 1,2,3,4,5 weeks after decompression, sections were regularly taken from the previously compressed area to perform morphometric analysis. RESULTS: After 2 weeks of decompression, the significant recovery were observed in both MNCV and Lan of four groups. Up to the 5th week of decompression, recovery of electrophysiology was significantly faster in group C and D than that of group A and B, particular in group C(P lt; 0.05), while group A compared with group B, there was no statistical difference in both MNCV and Lan(P gt; 0.05). Morphometric analysis showed that a lot of neural regeneration fibers were observed in group C and D after 3 weeks of decompression. CONCLUSION: Decompression can improve nerve conduction function significantly, while injection of lemithason in epineurium after decompression can promote the structure and function recovery of injured nerve.