Finite element analysis of DAI animal model caused by nonimpact with half bound head in cats / 生物医学工程学杂志

This study sought to make a biomechanical analysis of the diffuse axonal injury(DAI) animal model caused by nonimpact with half bound head in cats. A three-dimensional finite element model of cat's head was established. The head of an anesthetized cat was scanned in 2 mm section. The nods and element meshes were signed out according to the geometry of every section. The geometric data were put into the computer and the element mesh body of cat's head was established in vizi CAD system. The maximum stress, minimum stress and von Mises stress were calculated by Super SAP (93ed) finite elemental software when the force was loaded on the right or left side of model in zero section. The analysis showed that the maximum stress appeared in the anterior and posterior loaded point and extended to cranial base in the cranial shell. There was high stress in the brain surface also. Because of cerebellar tentorium, cerebral falx, petrosal bone and sellar process, the stress did not decrease equivalently while approaching the deep brain, but it was distributed in cerebral-cerebellar peduncles, brain stem, corpus callosum and basal ganglia area at high values. The results suggest that the stress caused by rotational force is widespreadly and unequivalently distributed in brain tissue, which is mainly effected by the cerebellar tentorium, cerebral falx and the irregular geometric forms of cranial bone.

Repair effect of Schwann cells modified by microgene pSVPoMcat on injured spinal cord in rats / 中华创伤杂志(英文版)

<p><b>OBJECTIVE</b>To observe the repair effect of Schwann cells (SCs) modified by microgene pSVPoMcat on injured spinal cord in rats.</p><p><b>METHODS</b>Semi-transection injury at the level of T(8) of spinal cord was made with cutting method on 120 Sprague Dawley (SD) rats. Then 40 rats implanted with SCs modified by microgene pSVPoMcat were taken as Group A, 40 rats implanted with simple SCs as Group B and the other 40 rats were taken as the control group (Group C). The functional recovery of the rats was observed through combined behavioral score (CBS) and cortical somatosensory evoked potential (CSEP), and the expression of the glial fibrillary acidic protein (GFAP) was measured with in situ hybridization and immunocytochemistry. At 3 months after operation, the rats were examined with magnetic resonance image (MRI), and the neurofilaments (NF) of the axons were stained with immunohistochemical method.</p><p><b>RESULTS</b>GFAP expression in Group A was significantly lower than that of the other 2 groups. MRI showed that the spinal signals in the injured area recovered fundamentally in Group A, didn't recover in Group B and malacia focus was found in Group C, which was same as the results of NF staining. Wave amplitudes in incubation periods in Group A and Group B tended to recover. It recovered to the normal level in Group A, which was similar to the results of CBS.</p><p><b>CONCLUSIONS</b>SCs modified by microgene pSVPoMcat can inhibit GFAP expression, improve the growth of the axons and the functional recovery of neurons after spinal cord injury.</p>

pSVPoMcat modifying Schwann cell to protect injured spinal neurons in rats / 中华创伤杂志(英文版)

<p><b>OBJECTIVE</b>To investigate the protective effect of pSVPoMcat (myelin basic protein microgene) modifying Schwann cell on injured spinal neurons.</p><p><b>METHODS</b>A model of rat spinal cord injured by hemisection was used. One hundred and twenty healthy SD rats of both sexes weighing 250-300 g were divided into three groups: Group A (n=40, treated with implantation of pSVPoMcat modifying Schwann cell), Group B (n= 40, treated with implantation of Schwann cell only) and Group C (n=400, treated with sham operation as the control). One week after operation the rat functional recovery was observed dynamically by using combined behavioral score (CBS) and cortical somatasensory evoked potentials, the spinal cord sections were stained by Nissl, acid phosphatase enzyme histochemistry and cell apoptosis was examined by methye green, terminal deoxynucleotidyl and the dUTP Nick end labeling technique. Quantitative analysis was done by computer image analysis system.</p><p><b>RESULTS</b>In Group A the injured neurons recovered well morphologically. The imaging analysis showed a result of Group A<Group B<Group C in the size of the neurons (P<0.01). The percentage of ACP (acid phosphatase) stained area and the rate of apoptosis sequence were groups A<B<C. The change of tendency was correlated to their function recovery according to CBS.</p><p><b>CONCLUSIONS</b>pSVPoMcat modifying Schwann cell implantation has protective effect on injured spinal neurons and promotes recovery of injured spinal cord function in rats.</p>

Treatment of cystic craniopharyngiomas by CT-guided stereotactic neuroendoscopic resection and intratumoral chemotherapy / 中国神经精神疾病杂志

Objective 　To investigate the treatment of cystic craniopharyngiomas by CT-guided stereotactic neuroendoscopic resection and intratumoral chemotherapy. Methods　16 cases of cystic craniopharyngiomas were partial resected by CT-guided stereotactic neuroendoscopy. Intratumoral chemotherapy with bleomycin were given postoperatively. Results　The clinical symptoms improved promptly after evacuations of cyst in all patients. No death or severe complications occurred. Follow-up (ranged from 2 to 3 years) CT or MRI indicated that the tumor cysts gradually regressed or disappeared. Conclusions　The treatment of CT-guided stereotactic endoscopic resection and intratumoral chemotherapy for cystic craniopharyngioma is safe and effective, which should be a very useful procedure in clinical practice.

Influence of intraspinal implantation of pSVPoMcat genetically modified schwann cell on regeneration of injured spinal cord / 中国组织工程研究

Objective In order to observe the role of genetically modified Schwann cell (SC) with pSVPoMcat in the regeneration of injured spinal cord.Method The cells were implanted into the spinal cord.Ninety SD rats were used to establish a model of hemi- transection of spinal cord at the level of T8,and were divided into three groups,randomly, that is,pSVPoMcat modified SC implantation(Group A), SC implantation(Group B),and without cell implantation as control(Group C).After three months the presence of axonal regeneration of the injured spinal cord was examined by means of horseradish peroxidase(HRP)retrograde labeling technique and stereography.Result The results indicated that HRP labeled cells in Group A and B could be found in the superior region of injured spinal cord and the brain stem such as the red nuclei and oculomotor nuclei. The density of ventral horn neurons of the spinal cord and the number of myelinated axons in 100 μ m of the white matter was A >B >C group.Conclusion In brief,the pSVPoMcat modified SC intraspinal implantation could promote regeneration of the injured spinal cord.

Protective Effects of Intracord Transplantation of pSVPoMcat Modified Schwann Cells on Spinal Cord Injury / 中国组织工程研究

Objective To study the protective effects of the intracord transplantation of microgene pSVPoMcat－ genetically－ modified Schwann cells (MSCs)on spinal cord injury (SCI).Method Rats with semi－ division(SD) of the spinal cord was divided into 4 groups.Group S consisted of the rats with SD treated with the transplantation of MSCs, Group B of the rats with SD treated with the transplantation of SCs without genetic modification,Group C of the rats with SD without treatment and Group D was the normal control. 8 hours after operation,the half of the rats of each group were killed and the injured segment of the spinal cord was resected to be examined with atomic absorption spectrophotometry . Another half of the rats of all the groups were examined with neurological function tests to have a combined behavioral score (CBS).Result There was a significant increase of water content and Na＋ and Ca2＋ ions and a decrease of K＋ and Mg 2＋ ions in the injured cord segment of Group C and a statistically significant recovery was observed in Group A. The intracord transplantation of pSVPoMcat genetically modidied SCs improved the neurological outcome of spinal cord injury.Conclusion Our findings indicate that intracord transplantation of pSVPoMcat－ genetically－ modified－ Schwanncells exerts protective effects on the injured segment of the spinal cord through the improvement of the internal ion environment of the spinal cord.

Effect of intracranial pressure and cerebral perfusion pressure on outcome prediction of severe traumatic brain injury / 中华创伤杂志(英文版)

OBJECTIVE: To investigate the influence of intra cranial pressure (ICP) and cerebral perfusion pressure (CPP) on neurological det erioration and outcome of severe traumatic brain injury (STBI). METHODS: A total of 245 patients with severe traumatic brain in jury were studied retrospectively with univariate and multivariate studies to ev aluate the contribution of ICP/CPP to neurological deterioration and outcome. RESULTS: The mortality rates rose from 16.2% in 142 patient s whose course of disease was smooth to 66.7% in 103 patients who suffered f rom neurological deterioration. Correspondingly, the favorable outcome fall from 54.2% in the patients without neurological deterioration to 18.3% in th ose with neurological deterioration. In the patients with clinical evidence of n eurological deterioration, the relative influence of the ICP and the CPP on outc ome was assessed. The most powerful predictors of neurological deterioration was the presence of intracranial hypertension (ICP>30 mm Hg, 1 mm Hg=0.133 kPa). The CPP also had a prognostic power on neurological deterioration when its level less than 60 mm Hg. CONCLUSIONS: It suggests that it's very important to lower the intracranial hypertension and keep the CPP not less than 60 mm Hg during the t reatment of STBI.

Association of oxidative stress inducing neuronal apoptosis with c-Myc,Fas-FasL and nuclear factor-?B / 中华创伤杂志

Objective To explore the relationship between oxidative stress inducing neuronal apoptosis and the protein expressions of c-Myc, Fas-FasL and nuclear factor ?B (NF-?B) in neurons. Methods The primarily cultured neurons of SD rat in vitro were divided into 5 groups: Group A (control), Group B (treated with hypoxia), Group C (treated with small dose of H 2O 2), Group D (treated with hypoxia and SOD) and Group E (treated with H 2O 2 and SOD). Then, the neuronal apoptosis was elevated with TUNEL,Gel electrophoresis and flow cytometry. The protein expressions of c-Myc, Fas-FasL and NF-?B were detected with immunohistochemistry. Results Apoptosis rates of the Groups B and C were 6 and 8 times than that of the Group A respectively ( P

EFFECT OF INTASPINAL IMPLANTATION OF MICROGENE pSVPoMcat GENETICALLY MODIFIED SCHWANN CELLS ON SPINAL CORD INJURY REPAIR IN RATS / 解放军医学杂志

To observe the effect of intaspinal implantation of Schwann cells (SC) genetically modified with microgene pSVPoMcat on spinal cord injury (SCI) repair.120 SD rats were used to establish the hemisected spinal cord injury model at T 8 level,and they were divided randomly into three groups: genetically modified SC implantation group (group A),normal SC implantation group (group B) and control group without cell implantation (group C).One week after the operation ,combined behavioral score(CBS) and the cortical somatasensory evoked potential (GFAP) were measured and the expression of glial fibrillary acidic protein(GFAP) was examined by in situ hybridization and immunocytochemistry.Three months after the operation, all the rats were scanned with MRI and then were sacrificed.Neurofilament (NF) was examined with imunohistocytochemistry staining by using NF monoclonal antibody. Following were the results:(1) In group A,the number of cells expressed GFAP in injured sites was less than that in groups B and C.(2) MRI scanning showed that the SCI region almost recovered in group A but did not recover in group B.There was a malacie focus in SCI region in group C.This was corroborated by the NF staining.(3) The amplitudes of potential in the latent period in group A and B showed a tendency to recover,and it was consistent with CBS.The results suggested that the implantation of genetically modified SC with microgene pSVPoMcat could inhibit GFAP expression and promote the functional recovery of spinal cord injury in rats.