BACKGROUND: Periventricular leukomalacia is a major syndrome of premature infant brain injury, which has been not prevented and cured yet. Theoretically, neural stem cells which were transplanted into white matter with an absence of oligodendroglial cells might be an ideal method to cure periventricular leukomalacia. OBJECTIVE: To prepare the multi-lineage potential of neural stem cells for the use of intraventricular transplantation. METHODS: Cerebral cortex was obtained from 12-14-day fetal rats and sectioned into 1.0-mm~3 sections. The single cell suspension was separated and purified. The neurospheres were incubated with DMEM/F12 culture medium containing fetal bovine serum to observe primary and passage culture of neural stem cells. The differentiation of neural stem cells was determined using immunohistochemical method. RESULTS AND CONCLUSION: The viability of cultured neural stem cells was (94.3±2.2)%. The neurosphere was formed at day 3 after primary culture. The proliferation of neurosphere slowed down after 10-passage culture, and some cells became old. All neurospheres were positively Nestin-staining, thus they were considered as neural stem cells. A further incubation of 4-passage neurospheres, immunohistochemical method indicated that the neurosphere was positively GFAP, β-tublin, and O4 staining, respectively. This suggested that cultured neural stem cells are able to self-renew, proliferate, and differentiate into neurons, astrocytes and oligodendroglial cells.

Objective To track superparamagnetic iron oxide (SPIO)-labeled pancreatic islet cells in rats using 3.0T magnetic resonance imaging (MRI), and to detect the survival and rejection of grafts after transplantation. Methods Twenty male Wistar rats and 5 male Lewis rats were included in the study. SPIO-labeled pancreatic islet cells were tracked using a GE 3.0T Signa Excite MRI scanner with an animal coil. The images of SPIO-labeled islet cells in rats after transplantation were compared with those of the unlabeled ones. FSE T2WI sequence and GRE T2*WI sequence were used for the detection. The sensitivity of images for detection of grafts was also compared. SPIO-labeled pancreatic islet cells isolated from Wistar and Lewis rats were transplanted into the liver of Wistar rats. Afterwards, the survival and rejection of islet cells were observed sequentially in these two growps. The rats in the syngeneic group were sacrificed 3 months post-transplantation, while the rats in the allogeneic group were sacrificed 3 weeks post-transplantation. MRI of the grafts were correlated with the pathological results. Results SPIO-labeled pancreatic islet cells were seen on MRI as distinct homogenous, hypointense spots in the liver. GRE T2*WI were more sensitive to the detection of SPIO-labeled islet cells than FSE T2WI. The relative count of hypointense spots in the syngeneic group were (90.03±9.52)%, (92.87±18.21)% and (86.25±24.81)%, respectively at 1 week, 2 weeks and 3 weeks after transplantation, while the relative count in the allogeneic group were (41.40±15.41)%, (33.41±14.01)% and (23.58±16.78)%, respectively. The difference between these counts was statistically significant (P<0.01). Iron particles were detected only in the SPIO-labeled cells. Three months post-transplantation, the grafts were found well-preserved in the liver of the rats of the syngeneic group, while only a few grafts were found in that of the allogeneic group. Conclusions MRI can be used to track SPIO-labeled islet cells in vivo, and has significant value in detecting the survival and rejection of grafts after transplantation in rats.

Objective To study the different patterns of hippocampal atrophy by MRI segmental analysis and to investigate the etiology and pathogenesis of temporal lobe epilepsy Methods GE 1 5 T Signa Horizon LX MRI scanner was used Oblique coronal T 1 weighted images perpendicular to the long axis of the hippocampus were obtained The mesial temporal structures were divided into four parts: the amygdala, hippocampal head, body and tail MRI patterns of atrophy in 50 patients with histologically confirmed hippocampal sclerosis were investigated by MRI volumetric measurement and segmental analysis, and the differences of clinical features and surgical outcome in different groups were compared Results Diffuse hippocampal atrophy was found in 22 of 50 patients (44%), 5 of the 50 patients (10%) showed diffuse atrophy involving both the amygdala and hippocampus 20 of the 50 patients (40%) had hippocampal focal atrophy and 8 of 50 patients (16%) had no obvious atrophy 38 of 50 (76%) hippocampal sclerosis had atrophy in the hippocampal body, 29 of 50 (58%) had hippocampal head atrophy, 24 of 50 (48%) had hippocampal tail atrophy, and the least involved part was the amygdala (16%, 8/50) 10 patients who had normal hippocampal volume showed focal hippocampal atrophy by segmental analysis Various patterns of hippocampal atrophy were found to be statistically related to the duration of epilepsy, the frequency of seizure and the outcome of surgery, respectively ( P 0 05) Conclusion MRI segmental analysis can improve the diagnostic sensitivity of temporal lobe epilepsy and help to investigate its etiology and pathogenesis

Objective To evaluate the microstructural integrity of white matter (WM) in patients with amnestic mild cognitive impairment (aMCI) and mild Alzheimer's disease (AD) using voxel-based analysis (VBA), and investigate the relationship between WM abnormalities and gray matter(GM) atrophy.Methods Thirty-three cases with aMCI, 32 cases with mild AD and 31 normal aging volunteers as control subjects were scanned on a 3.0 T MR system using diffusion tensor imaging (DTI) and three-dimensional spoiled gradient-recalled(3DSPGR) sequences. Fractional anisotropy (FA) maps and morphological images were preprocessed by SPM5 and voxel-based comparisons between the 2 patient groups and the control group were performed by t test. Results Relative to the control group, patients with aMCI showed significantly reduced FA value in bilateral frontal, temporal and left occipital WM, left anterior part of cingulum, left inferior parietal lobule, and the W M adjacent to the triangular part of the right lateral ventricle(k≥20 voxels).In mild AD,significantly reduced FA value was found in bilateral hippocampal,inferior parietal lobular,frontal,temporal,and occipital WM,bilateral corpus callosum,anterior part of cingulums,the WM adjacent to the triaangular part of the bilateral lateral ventricles,left temporal stem,left thalamus,right precuneus(k≥20 voxels).Significantly reduced GM volume was found in left hippocampus,parahippocampal gyrus,lingual gyrus and superior temporal gyrus,bilateral insulae and middle temporal gyri in aMCl group whencompared with control group(k≥50 voxels).In mild AD,significantly reduced GM volume was found in bilateral hippoeampi,parahippocampal gyri,amygdalae,thalami,temporal,parietal,frontal,occipital cortex(k≥50 voxels).The pattern of areas with reduced FA differs;from that of the GM volumetric reduction.No areas with significantlv reduced FA was detected in aMCl compared with mild AD. There was no significant correlation between FA value of WM in patient groups and Mini-Mental State Examination(MMSE)scores.Conclusions Voxel-based MRI DTI analysis of whole brain white matter can objectively reveal widespread white matter abnormalities in early-stage AD.The difierence between WM FA reduction pattern and GM volumetric reduction pattern indicates that the pathological WM changes in earlyslage AD were caused by multiple mechanisms. FA did not vary significantly in patients pr0gressing from aMCI to mild AD and can hardly reflect the severitv of cognitive function damage in these patients.

Objective To study the value of relative cerebral blood flow(rCBF)changes in patients with amnestic-type mild cognitive impairment (aMCI)and mild Alzheimer disease(AD) using MRI pulsed arterial spin labeling(PASL).Methods A prospective study recruited 37 aMCI patients (aMCI group),30 mild AD patients(mild AD group) and 30 healthy volunteers (normal control group) from March 2011 to December 2013,MRI using PASL for cerebral perfusion imaging was performed and data of rCBF were collected.Taking age as covariate,analysis of variance (ANONA)was carried out to assess the difference of rCBF among all the three groups,then Bonferroni was done between every two groups.A follow-up examination using PASL was performed in the seventeen patients of the aMCI group.And paired t-test was used for comparing the longitudinal change of their rCBF data.Results Compared with the normal control group,the aMCI group showed significant increase of rCBF in bilateral posterior cingulate cortices and precuneus (cluster number 2 785,P＜0.05).While the mild AD group showed decrease of rCBF in the left inferior and superior parietal lobes,the angular,middle frontal lobe,as well as the right superior temporal lobe (cluster number 3 459-5 206,P＜0.05).When compared with the aMCI group,the mild AD group showed regional hypoperfusion in bilateral middle frontal lobes,the left precuneus,the right postcentral and inferior parietal lobe (cluster number 3 236-19 863,P＜0.05).In the longitudinal study of the 17 aMCI patients,an increased rCBF was found to coexist with reduced rCBF in the left inferior frontal and lateral occipital cortex,bilateral frontal poles and paracingulate gyrus,with hyperperfusion dominated.Increased rCBF was also detected in the left temporal lobe,the angular gyrus and precuneus,while decreased rCBF was present in the left putamen,the operculum and right corpus callosum (P＜0.05).Conclusions ASL perfusion imaging is a valuable method for dynamic monitoring of the cerebral perfusion changes in aMCI and AD patients.PASL will assist in finding a useful imaging biomarker for early diagnosis of AD.

Objective To study the protective effect of curcumin on precurosor oligodendrocytes (preOLs) damage induced by hydrogen peroxide (H2O2),and explore its mechanism.Methods (1) In vitro primary culture ofpreOLs was performed; and 0 (normal controls),100,250 and 500 μmol/L H2O2 were added for 30 min; the apoptosis and death of preOLs were observed by Hoechst33342/PI double staining.(2) The preOLs were divided into normal control group,model group,and 5,10 and 20 μmol/L curcumin treatment groups; cells the later three groups were given 5,10 and 20 μmol/L curcumin for one h,and the later four groups were given 100 μmol/L H2O2 for 30 min; MTT assay was,then,employed to detect the cell viability.(3) The preOLs were divided into normal control group,model group,and 10 μmol/L curcumin treatment group; the apoptosis ofpreOLs was detected by Annexin V/FITC flow cytometry; Western blotting was used to detect the protein expressions of B cell lymphoma/leukemia-2 (Bcl2),Bcl-2 associated X protein (Bax) and cleaved caspase-3 and caspase-9; activities of total superoxide dismutase (T-SOD),glutathione peroxidase (GPx) and catalase (CAT) and malondialdehyde (MDA) were detected by spectrophotometry.Results (1) As compared with those in the normal control group,significantly decreased number of normal healthy cells and statistically increased apoptotic and necrotic cells in the 100,250 and 500 μmol/L H2O2 treatment groups were noted (P＜0.05); 100 μmol/L H2O2 treatment group had larger number of apoptotic cells than that of necrotic cells,while 250 and 500 μmol/L H2O2 treatment groups had larger number of necrotic cells than that of apoptotic cells.(2) Cells from 5,10 and 20 μmol/L curcumin treatment groups had significantly higher preOLs viability than those from model group,and 10 and 20 μmol/L curcumin treatment groups had significantly higher preOLs viability than those from 5 μmol/L curcumin treatment group (P＜0.05).(3) As compared with the model group,the 10 μmol/L curcumin treatment group had obviously decreased apoptotic and necrotic cells,increased activities of T-SOD,GPx and CAT,increased GSH level and decreased MDA concentration,up-regulated Bcl-2 expression,and inhibited Bax,caspase-3 and caspase-9 expressions,with significant differences (P＜0.05).Conclusion Curcumin has protective effect on preOLs against oxidative injury through effectively reducing lipid peroxidation,regulating Bcl-2/Bax expression and suppressing caspase-3 and caspase-9 activation.

Objective To evaluate the role of local gyrification index (LGI) in the early diagnosis of Alzheimer disease(AD). Methods Thirty‐five amnestic‐type mild cognitive impairment patients (aMCI group), 34 mild AD patients (mild AD group) and 33 healthy volunteers (normal control group) were studied. All patients underwent high resolution MRI examination and mini‐mental state examination (MMSE). Using surface‐based morphometry, the FreeSurfer was employed to access LGI of vertex over every participant′s whole cortical surface, then we calculated the mean LGI (mLGI) of each subject′s left and right hemisphere separately. Taking age, gender and educational year as covariance, analysis of covariance was used to compare the difference of mLGI of left and right brain among 3 groups, then Bonferroni was done between every two groups. Analysis of covariance was applied to compare the difference of LGI of every participant among 3 groups, and Monte Carlo method was employed to perform multiple comparison corrections. The correlations between the MMSE scores and LGIs of the three groups were analyzed. Results Compared with normal control group(left 3.03±0.12,right 3.02±0.13), the mLGI of hemispheres in mild AD group(left 2.94±0.11,right 2.93±0.10) decreased respectively(P<0.05). The difference of mLGI of hemispheres between aMCI group(left 2.96 ± 0.10, right 2.96 ± 0.09) and normal control group had no statistical significance(P>0.05). The difference of mLGI of hemispheres between aMCI group and mild AD group also had no statistical significance(P>0.05). The aMCI group showed decrease of LGI in some brain regions located at the right temporal lobe, bilateral frontal and parietal lobe compared with the normal control group. While compared with aMCI group, decreased LGIs was presented in some brain regions located at bilateral temporal, occipital, frontal lobe and the right parietal lobe of mild AD group. There was a positive correlation between MMSE scores and LGIs of some brain regions in the bilateral temporal, occipital lobe, the left frontal lobe and the right parietal lobe in the three groups. Conclusion LGI is conductive in the early diagnosis of AD and can serve as an imaging marker for monitoring disease progresses.

Objective:To investigate the blocking effect of non-competitive N-methyl-D-aspartic acid(NMDA) receptor antagonist Memantine on glutamate abnormal signal transmission in immature white matter induced by ischemia in vitro and in vivo. Methods:The oligodendrocyte (OL) precursor oxygen glucose deprivation (OGD) cell models of 2-day-old newborn rats were prepared and divided into the normal control group, the OGD group and the Memantine group.The extracellular glutamate level of the OL precursor was measured by high performance liquid chromatography, while the concentration of intracellular calcium and the apoptosis rate of OL precursor were detected by flow cytometry.The animal models of ischemic periventricular leukomalacia (PVL) were established and divided into the sham group, the PVL group and the Memantine group.The pathological evaluation of white matter was performed under light microscope.The positive OL expression rate of myelin basic protein(MBP) was detected by immunohistoche-mistry.The myelination of white matter was evaluated under electron microscope.Results:Compared with the normal control group in vitro, the OGD group had a higher extracellular glutamate level of the OL precursor [(24.60±2.42) μmol/L vs.(9.49±1.08) μmol/L, t=9.28, P<0.01], a higher intracellular calcium concentration [(32.9±6.9)% vs.(6.9±3.5)%, t=4.41, P<0.01], a higher apoptosis rate of the OL precursor [(24.77±2.05)% vs.(6.65±1.39)%, t=15.01, P<0.01]. After treatment with Memantine, the extracellular glutamate level [(14.70±1.70) μmol/L, t=5.68, P<0.01], the intracellular calcium concentration [(23.1±2.0)%, t=6.13, P<0.01], and the apoptosis rate of the OL precursor [(11.80±2.06)%, t=5.18, P<0.01] decreased significantly.Compared with the sham group in vivo, the white matter of the PVL group showed mild or severe pathological changes, and the PVL group had a lower MBP-positive OL expression rate in the white matter [(5.94±1.37)% vs.(15.40±3.22)%, t=4.63, P<0.01]less myelin sheaths (4.00±1.00 vs.14.67±2.70, t=6.11, P<0.01) and thinner myelin sheaths [(33.83±3.21) nm vs.(79.67±6.45) nm , t=10.43, P<0.01]. After the treatment with Memantine, the number of myelin sheaths (10.30±1.50, t=6.01, P<0.01), the thickness of myelin sheaths [(57.21±4.05) nm, t=7.47, P<0.01], and the pathological changes in the white matter of newborn rats ( Z=88.479, P<0.01) all improved markedly, and the MBP positive OL expression rate in the cerebral white matter [(11.02±1.35)%, t=4.40, P<0.05] also increased significantly. Conclusions:Ischemia-induced abnormal signal transmission of glutamate in immature white matter is the important pathway leading to ischemic PVL.Memantine can effectively block the abnormal signal transmission and thus may probably provide a new approach for the effective prevention and treatment of PVL in premature infants.