ABSTRACT
The chronological and spatial rules of changes during focal cerebral ischemia and reperfusion in different brain regions with magnetic resonance diffusion-weighted imaging (DWI) in a model of occlusion of middle cerebral artery (MCAO) and the development of cytotoxic edema in acute phase were explored. Fifteen healthy S-D rats with MCA occluded by thread-emboli were randomly divided into three groups. 15 min after the operation, the serial imaging was scanned on DWI for the three groups. The relative mean signal intensity (RMSI) of the frontal lobe, parietal lobe, lateral cauda-putamen, medial cauda-putamen and the volume of regions of hyperintense signal on DWI were calculated. After the last DWI scanning, T2 WI was performed for the three groups. After 15min ischemia, the rats was presented hyperintense signals on DWI. The regions of hyperintense signal were enlarged with prolonging ischemia time. The regions of hyperintense signal were back to normal after 60 min reperfusion with a small part remaining to show hyperintense signal. The RMSIs of parietal lobe and lateral cauda-putamen were higher than that of the frontal lobe and medial cauda-putamen both in ischemia phase and recanalization phase. The three groups werenormal on T2WI imaging. DWI had good sensitivity to acute cerebral ischemia, which was used to study the chronological and spatial rules of development of early cell edema in ischemia regions.
ABSTRACT
The chronological and spatial rules of changes during focal cerebral ischemia and reperfusion in different brain regions with magnetic resonance diffusion-weighted imaging (DWI) in a model of occlusion of middle cerebral artery (MCAO) and the development of cytotoxic edema in acute phase were explored. Fifteen healthy S-D rats with MCA occluded by thread-emboli were randomly divided into three groups. 15 min after the operation, the serial imaging was scanned on DWI for the three groups. The relative mean signal intensity (RMSI) of the frontal lobe, parietal lobe, lateral cauda-putamen, medial cauda-putamen and the volume of regions of hyperintense signal on DWI were calculated. After the last DWI scanning, T2 WI was performed for the three groups. After 15 min ischemia, the rats was presented hyperintense signals on DWI. The regions of hyperintense signal were enlarged with prolonging ischemia time. The regions of hyperintense signal were back to normal after 60 min reperfusion with a small part remaining to show hyperintense signal. The RMSIs of parietal lobe and lateral cauda-putamen were higher than that of the frontal lobe and medial cauda-putamen both in ischemia phase and recanalization phase. The three groups were normal on T2 WI imaging. DWI had good sensitivity to acute cerebral ischemia, which was used to study the chronological and spatial rules of development of early cell edema in ischemia regions.
Subject(s)
Brain Ischemia/pathology , Diffusion Magnetic Resonance Imaging/methods , Early Diagnosis , Infarction, Middle Cerebral Artery/pathology , Random Allocation , Rats, Sprague-Dawley , Reperfusion Injury/pathology , Time FactorsABSTRACT
BACKGROUND: Being a kind of regenerative and auto-transplanting cell, olfactory ensheathing cell (OEC) has been extensively concerned on transplantation treatment for spinal disease. Concerning to the transplantation in treatment of cerebral hemorrhage, it is expected a further accumulation of experimental results at present.OBJECTIVE: To observe the proliferation of neural progenitor cells in cerebral hemorrhagic rats after OEC transplantation and to evaluate the therapeutic effects of OEC transplantation on cerebral hemorrhage.DESIGN: Completely randomized controlled experiment.SETTING: Department of Neurology of Tongji Hospital affiliated to Tongji Medical College of Huazhong University of Science and Technology.MATERIALS: The experiment was performed in Research Center for Clinical Neurology , Tongji Medical College of Huazhong University of Science and Technology from March 2002 to March 2003. Thirty-two healthy male Wistar rats were employed and randomized into 2 groups, 16 rats in each. In OEC transplantation group, on the 3rd day of modeling hemorrhage of caudate nucleus, OEC suspension 10 μL was injected evenly in the brain of rat (1 μL/min). In the control group, physiological saline 10 μL was injected.METHODES: Neural function evaluation was done before transplantation,on the 3rd, 7th, 14th and 30th days after transplantation successively. On the first day after modeling, 1 rat was collected from each of two groups to prepare brain tissue section. Myelin sheath blue staining was used for observation of neuronal axonal myelin sheath. Never fiber argentophil staining was used for observation of never fiber. One rat was collected from each of two groups on the 3rd, 7th, 14th and 30th days after transplantation successively to prepare paraffin section. The survival and migration after OEC transplantation as well as proliferation of neural progenitor cell were observed.The count of neural progenitor cell was recorded.myelin sheath and nerve fiber after cerebral hemorrhage in rats of two function deficits on the 3rd, 7th, 14th and 30th days after cerebral hemorrhage in rats of two groups.around and in hematoma on the 30th day after cerebral hemorrhage: In transplantation group, myelinated amount and nerve fiber amount were cell after cerebral hemorrhage in rats of two groups: on the 7th, 14th and 30th days after cerebral hemorrhage, the amount of neural progenitor cell in OEC transplantation group was more remarkably than that in the control group [(41.1 ±2.4)pcs/vision field, (34.5 ±1.2)pcs/vision field; (43.6±1.2)pcs/vision rield, (37.2±2.0)pcs/vision field; (19.3±1.0)pcs/vision rield, ( 14.2±0.4)pcs/videficits after cerebral hemorrhage in rats of two groups: In OEC transplantation group, on the 14th and 30th days, the evaluation was lower remarkably than the 3rd day [(2.21 ±0.20)scores, (1.50±0.21)scores, (2.74±0.21)scores, (t=2.06, 3.27, P ＜ 0.05)]. In the control group, that on the 30th day after cerebral hemorrhage was lower than that on the 3rd day [(1.96±0.12)scores ,(2.76±0.20) scores, (t=2.47, P ＜ 0.05 )].tion of intracerebral nerve cell, re-myelination and building-up synaptic system so as to recover the motor function and accelerate repair of injured tissue.
ABSTRACT
The expression of hypoxia inducible factor-1 alpha (HIF-1alpha) and its relationship to apoptosis in tissues around cerebral bleeding loci was studied. The expression of HIF-1alpha and apoptosis in 37 samples of tissues around cerebral bleeding loci and 9 samples of normal cerebral tissues was assessed by immunohistochemical straining and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling methods. In 37 tissue samples around cerebral bleeding loci, the positive rate of the HIF-1alpha expression was 40.6%. Especially in the patients with amount of bleeding >60 ml, the positive rate (88.9%) of the HIF-1alpha expression was significantly higher than those with the amount of bleeding ranging from 30-45 ml or 45-60 ml (P<0.05). The expression of HIF-1alpha was increased as the amount of bleeding and operative time increased (P<0.05). There existed a positive correlation between HIF-1alpha labeling index and apoptosis index (n=12, r=0.56, P<0.01). These results suggested that the expression of HIF-1alpha was closely related with the time of hemorrhage and the amount of bleeding, and could induce the apoptosis of neurons.