Neural Stem Cells Transfected with Leukemia Inhibitory Factor Promote Neuroprotection in a Rat Model of Cerebral Ischemia / 神经科学通报·英文版

Leukemia inhibitory factor (LIF) contributes to the neuroprotection by neural stem cells (NSCs) after ischemic stroke. Our aim was to explore whether LIF-transfected NSCs (LIF-NSCs) can ameliorate brain injury and promote neuroprotection in a rat model of cerebral ischemia. To accomplish this goal, we transfected NSCs with a lentivirus carrying the LIF gene to stably overexpress LIF. The LIF-NSCs reduced caspase 3 activation under conditions of oxygen-glucose deprivation in vitro. Transient cerebral ischemia was induced in rats by 2 h of middle cerebral artery occlusion (MCAo), and LIF-NSCs were intravenously injected at 6 h post-ischemia. LIF-NSC treatment reduced the infarction volume and improved neurological recovery. Moreover, LIF-NSCs improved glial cell regeneration and ameliorated white matter injury in the MCAo rats. The NSCs acted as carriers and increased the expression of LIF in the lesions to protect against cerebral infarction, suggesting that LIF-NSCs could be a potential treatment for cerebral infarction.

Mechanism of recovery of dysphagic patients caused by stroke:A fMRI study / 中华物理医学与康复杂志

Objective To study the recovery mechanism of dysphagic patients after stroke using functional magnetic resonanee imaging(fMRI). Methods Thirteen patients with dysphagia caused by unilateral cortical or subcortical lesions were recruited into a dysphagia group,and eight age-matched healthy volunteers were recruited as controls.Both grouDs performed experimental volitional swallowing tasks during fMRI studies.All patients of the dys-phagia group received rehabilitation treatment targeting dysphagia.Of the 13 dysphagia patients,7 reached almost complete recovery and were identified as recovered in follow-up fMRI studies.A 3.0 T MR scanner and echo planar imaging(EPI)T_2 WI sequence were employed to obtain the fMRI data.SPM2 software was used for post-processing of the fMRI data and displaying activated brain maps.Lateral index(LI)was calculated as LI:(C-1)/(C+I).Paired t tests were used to compare activated brain volume before and after complete recovery. Results Consistent activation of the bilateral primary sensorimotor cortex,anterior cingulated gyrus and the bilateral insular cortex were observed in the control group. Activation of the pons,medulla,left cerebellum,left prefrontal area,right occipital area and the left insular cortex were observed in the dysphagia group.Activation was observed in the bilateral primary sensorimotor cortex.bilateral prefrontal area,bilateral superior temporal gyrus,left insular cortex,bilateral frontal o-pereulum and anterior cingulated gyrus in the recovered patients.The total activated volume before recovery in the ip-silesional hemisDhere was significantly less compared with the contralesional hemisphere in the dysphagia group.In the recovered patients,both the activated brain volume of the ipsilesional hemisphere and value of LI were significant-ly larger than those at the initial examination.Conclusions Decreased activation in the sensorimotor cortex,the in-sular lobe and the cingulate gyms might be causes.of dysphagia.Compensation by the contralesional hemisphere in the early stages and then the restoration of the ipsilesional hemisphere after recovery may be mechanisms of dysphagia recovery in stroke patients.

Diffusion tensor imaging for gliomas grading at 3.0T MR: Analysis of apparent diffusion coefficient and fractional anisotropy / 中国医学影像技术

Objective To assess the value of apparent diffusion coefficient (ADC) and fractional anisotropy (FA) value at 3.0T diffusion tensor imaging (DTI) in glioma grading before operation. Methods DTI was performed on 104 patients with histologically proved glioma. ADC, FA and DWI maps were produced, and ADC, FA value of solid tumors were measured and compared with the WHO classification of gliomas. Results Fifty-eight gliomas were WHO Ⅱ, 25 were WHO Ⅲ and 21 were WHO Ⅳ. The ADC value of WHO Ⅳ (0.81±0.20)×10~(-3)mm~2/s was lower than that of WHO Ⅲ [(1.05±0.30)×10~(-3)mm~2/s] and WHO Ⅱ[(1.26±0.32)×10~(-3)mm~2/s (P=0.008, P＜0.001)]. The ADC value of WHO Ⅲ was lower than that of WHO Ⅱ (P=0.003). The FA value of WHO Ⅳ (0.18±0.06) was higher than that of WHO Ⅱ (0.15±0.06) (P=0.046). No significance of FA was found between WHO Ⅲ (0.15±0.10) and Ⅱ, nor WHO Ⅳ and Ⅲ. Conclusion ADC and FA value can distinguish different grade gliomas. It is useful in deciding the surgical strategy and predicting the patient's prognosis.

Investigating effect of fusion gene therapy by MR diffusion-weighted imaging in a rat C6 glioma model / 中华放射学杂志

Objective To evaluate the use of diffusion-weighted imaging(DWI)for early detection of tumor response to Angiostatin-Endostatin(Statin-AE)fusion gene therapy in a rat C6 glioma model.Methods Fifty male wistar rats with C6 tumor cells implanted into the striatum were examined by a 3.0T MR scanner,then the rats beating tmors were divided into two groups,treatment group and control group.Rats in the treatment group received 107 plaque forming unit(pfu)recombinant herps simplex viral (R-HSV)mediated Statin-AE fusion gene therapy on day 7,and then the tumors were conformed on MRI.Conventional MR and DWI examination were acquired on 1,2,3 weeks after implantation with a 5-inch surface coil.Two(1 w),eight(2 w)and all the residual rats(3 w)of each group were sacrificed to perform the histopathological examination after each MBI examination.Pretreatment and post treatment tumor volulnes and apparent diffusion coefficient(ADC)values were calculated.Rank sum test and t test were employed for statistical analysis.Results On MRI,43 rats demonstrated tumors on day 7 with a successful rate of 86%,On week 2,the tumor volumes of the controh and treatment group were 90.6 and 91.64 mm3,with no significant difference(Z=-0.14,P＞0.05).On week 3,the tumor volumes of the controls and treatment group were 156.64 and 29.64 mm3,and a significant difference was observed(Z=-3.45,P＜0.01).On week 2.the ADC values of the tumor centers of the treatment group and the control group were (1.20±0.25)×10-3 and(0.99±0.08)×10-3 mm2/s,and the values of the tumor peripheral parts of the two groups were(1.00±0.25)×10-3 and(0.83±0.12)×10-3mm2/s,the ADC values of both tumor centers and peripheral parts of the treatment group were significantly higher than those of the control group (t=-0.82 and-0.46,P＜0.05).On week 3,the ADC values of the tumor centers of the treatment group and the control group were(0.92±0.21)× 10-3 and(0.99±0.09)×10-3mm2/s,and the values of the tumor peripheral parts of the two groups were(0.81±0.19)×10-3 and(0.78±0.11)×10-3 mm2/a,there were no statisfical difference between the two groups(t=0.82,and-0.46,P＜0.05).HE stained slices showed more prominent tumor interstifial edenla.swelling and death of tumor cells in the treated rats than the controls.Conclusions Combination of conventional MRI and DWI can be powerful to monitor tumor progression and therapy effecL Conventional MRI showed that the therapy slow the tumor progression in size while DWI demonstrated the tumor response even earlier than size change.DWI has potential use forthe detection of early response to antiangiogenic gene therapy.

Cerebral angiography and MR perfusion images in patients with ischemic cerebral vascular disease / 中华医学杂志(英文版)

<p><b>OBJECTIVE</b>To evaluate the value of perfusion MR imaging and angiographic evidence of collateral circulation in symptomatic patients with ischemic cerebrovascular diseases (ICVD).</p><p><b>METHODS</b>Cerebral angiography and perfusion MR were performed in 16 patients with symptoms of ICVD. Qualitative perfusion maps were calculated for regional cerebral blood volume (rCBV) and mean transit time (MTT).</p><p><b>RESULTS</b>A total of 27 lesions were seen on the perfusion MR maps (6 infarcts and 21 ischemic lesions) and most of them (26/27) showed a prolonged MTT. MTT is sensitive to the presence of ischemic lesions, but not sufficient in distinguishing infarct from ischemia. All of the infarcts showed a decreased rCBV, while most of the ischemic lesions showed a normal or increased rCBV. When collateral circulation was identified on angiography, most ischemic lesions were not infarcts and had a normal or increased rCBV. The absence of angiographically identifiable cerebral collaterals may not always result in an infarct; 50% had decreased rCBV. Despite the absence of angiographic collaterals, the other half had normal or increased rCBV.</p><p><b>CONCLUSION</b>Cerebral angiographic evidence of collateral circulation is important in identifying a favorable outcome in patients with ICVD. However, a lesion with a normal or increased rCBV suggests a sufficient collateral circulation even without angiographic collaterals. Perfusion images may be a potentially useful adjunctive tool in the prediction of the outcome of ICVD, particularly where no apparent collateral macrocirculation is seen on CA.</p>

Pre-and postsurgical location and evaluation of the motor hand area with functional MR imaging in patients with intracranial lesions involving motor cortex / 中华放射学杂志

Objective To examine the intracranial lesions before and after operation by functional MRI with BOLD technique, and to map the brain activation images of the patients on general MR images. Methods Thirty one patients had lesions involving the frontal and/or parietal lobes in one side of the cerebral hemispheres, and the lesions included 29 tumors (11 gliomas; 13 metastases; 5 meningiomas) and 2 infections. MSEPI technique was performed with four scan planar parallel AC PC. During each scan series, the patients were asked to perform repetitive finger thumb opposition movement in the same period of active and rest duration. All the scanning data were transferred to a workstation and dealt with statistical method. The patients had been examined again by the same sequence protocol postoperatively, and the fMRI images were analyzed and compared with that of the preoperation fMRI. Results The motor cortex of both cerebral hemisphere was asymmetrical, and the border between the motor cortex and lesions could be clearly identified in all of the patients preoperatively. After operation, both sites of the motor cortex were nearly replaced. Conclusion fMRI was very useful in evaluating the surgical planning and the prognosis of the patients.

The MR Diagnosis of Giant Intracranial Aneurysms / 实用放射学杂志

Objective To analysis the imaging appearances of giant intracranial aneurysms(GIA).Methods Forty pathological proven GIA were included in this study.Results The MR appearances were variable depending on the present of thrombosis,the size and age of the thrombosis,and the secondary changes of the GIA.The typical flow void presented in majority patients.The flow artifacts were displayed across the residual lumen in the phase direction of MR image.The residual lumen showed dense contrast enhancement.The thrombosis was found in 26 GIAs with variable signal intensity from homogeneous hypo-or hyperintensity to onion or turbo like heterogeneous signal intensity without contrast enhancement.DSA studies displayed residual lumen of GIAs and fail to display totally thrombosis GIAs.Conclusion MR studies clearly show the residual lumen and thrombosis of GIAs.MR study is an important conjunctive tool of the DSA studies in diagnosis GIA.