MR imaging of tropomyosin-4 antibody targeting synthetic phenotype vascular smooth muscle cells in vitro / 中华放射学杂志

Objective To isolate,culture,and identify the synthetic phenotype vascular smooth muscle cells (VSMC) and identify the specific marker protein (tropomyosin-4,TPM-4) of synthetic phenotype.To employ the immune molecular imaging technique to develop MRI of probe targeted with TPM-4 antibody VSMC in vitro.Methods The synthetic phenotype VSMC and endothelial cells (EC) were isolated and cultured in vitro,respectively.Immunocytochemistry (ICC) staining for α-smooth muscle actin (SMA) and Ⅷ factor was performed for cell identification,respectively.The high expression level of TPM-4 protein was tested by immunofluorescence double staining.The MRI molecular probe was built by chemical cross-linking,TPM-4 conjuncted probe (TPM4-USPIO) as the experimental group,IgG conjuncted probe (IgG-USPIO) as the negative group,unconjuncted probe (USPIO) as the control group,and PBS as the blank group.The synthetic VSMC were incubated with probes within experimental group,negative group,control group,respectively,and EC were incubated with experimental group as another control group.Prussian blue staining was employed to analyze the specific-targeting and MTT assay was used to test bioactivity of the probe under different concentrations (0,5,10,20,40 μg/ml) in vitro.7.0 T MRI scanner was used to detect the magnetic properties.With 7.0 T MRI scanner,the T2WI images of different probes labeled synthetic VSMC and different concentration gradient (1 × 103,5 × 103,1 × 104,5 × 104)TPM4-USPIO labeled cells were obtained and analyzed.T2 signal and MTT data among groups were compared using single factor analysis of variance (ANOVA) and LSD test.Results The synthetic phenotype of VSMC were isolated and cultured successfully,and the VSMC could express the TPM-4 protein.The synthetic phenotype VSMC had a high level of the protein expression.The probe was made successfully.The T2 relaxivity of TPM4-USPIO and IgG-USPIO were 0.0350 × 106,0.0316 × 106 mol/s,respectively,with high stability as USPIO (0.0292 × 106 mol/s).Prussian blue staining results showed that the experimental group probe could specifically bind to the synthetic VSMC.MTT results showed that iron concentration within 40 μg/ml or less had no effect on VSMC proliferation activity.The T2 WI of experimental group showed lower signal than the control group.The T2 relaxivity was (116.67 ± 2.08) ms,which was less than the control group [(217.67 ±2.52),(219.33 ±2.08)ms,respectively] and the blank group [(205.33 ± 1.53)ms](F =1670.43,P ＜ 0.01).The T2 relaxivity of the different concentration gradient labeled cells (1 × 103 、1 × 104 、1 × 105) were (184.33 ± 2.08),(169.67 ± 1.15),(116.67 ± 2.08) ms,respectively (F =684.35,P ＜0.01).No significant difference of the T2WI gradual signal dim was found between cells with the same order concentration(P ＞ 0.05).Conclusions The synthetic phenotype of VSMC can be obtained by PDGF-BB treatment.TPM4-USPIO probe is efficient,specific and targeted at combination with synthetic VSMC.The T2WI signal changed obviously under high field MRI scanner,which provides a new way for molecular imaging research.

Detection of cortical architecture of rat brain using high-resolution 7.0 T manganese-enhanced MRI in vivo / 中华放射学杂志

Objective To study the role of manganese-enhanced MRI(MEMRI) in the depiction of cortical architecture of rat brain after systemic administration of Mn~(2+) through caudal vein and compare the effects of normal or opened blood-brain barrier on the manganese-enhanced MRI. Methods Fifteen SD rats were randomly divided into three groups according to ranked list of random. Blood-brain barrier was opened in short time by the injection of 30% mannitol via the right internal carotid artery, in group A, then 100 mmol/L MnCl_2 physiologic saline solution was delivered through vena caudalis, and MRI was performed 12 hours later. In group B, 100 mmol/L MnCl_2 physiologic saline solutions was administrated through vena caudalis, following normal saline injection into the right internal carotid artery, and MRI was performed 12 hours later. The group C served as normal control group. All images were acquired with a 7.0 T microMR scanner. Signal-to-noise ratios (SNR) in regions of interest were measured by Paravision 4.0 and the differences of three groups were compared by using one-way ANOVA. The differences of SNR on both sides of hemispheres were compared by using paired t test. Results MEMRI could show the gray matter and white matter of rat brain and the anatomy borders between somatosensory cortex and motor cortex clearly. Periventricular structures such as hippocampus, dentate gyms, habenula united, and olfactory bulb could also be showed clearly. Symmetrical enhancement on both sides of the cortex and banded structures was shown clearly in group B. The SNR increased and the differences were significant in right cerebral cortex, both sides of cerebellar cortex, hippocampus and pituitary, among three groups (right cerebral cortex 35.2±7.0,30.1±2.4,26.6±2.8,F =4.36,P=0.038;left cerebellar cortex 27.1±5.2,29.4±3.8,19.4±4.5, F=6.66, P=0.011;right cerebellar cortex 27.8±3.8,28.5±4.2,20.4±4.8, F=5.84, P=0.017; left hippocampus 34.5±4.9,38.1±5.3,24.5±3.6, F=11.38, P=0.002; right hippocampus 35.3±5.5, 37.6±4.7,25.6±3.0,F=9.93,P=0.003;pituitary 39.5±3.8,52.6±9.1,26.2±4.2,F=22.80, P=0.001) after systemic administration of Mn~(2+). Asymmetric enhancement on two sides of cortex was shown in group A. The mannitol-infused side was enhanced obviously but displayed blurring banded structures. However,the SNR differences of both sides of hemispheres in group A and B were not significant (P >0.05). Conclusions After systemic administration of MnCl_2 through vena caudalis, MEMRI could map the laminar architectures and the anatomy border of functional zone of somatosensory cortex specifically. High concentration of mannitol could open blood brain barrier(BBB) effectively and have distinct impacts on the architectures displayed in MEMRI. Opening or maintaining BBB in MEMRI had respective characteristics, and it should be selected according to practical needs.

Experimental comparison study of the tissue characteristics in transjugular intrahepalic portosystemic shunt and vascular stent / 中华放射学杂志

Objective To investigate the tissue characteristics within vascular stent and transjugular intrahepatic portosystemic shunt(TIPS)on swine and to provide more information for the understanding and prevention of vascular stent and TIPS restenosis.Methods Animal models for TIPS were built in 6 swine and vascular stents were implanted in iliac veins simultaneouly.14-28 days after the operation.the 6 swine were killed to remove the TIPS and vascular stent and the pathological examinations were performed on the tissues within the shunt and stent.The similarities and difierences of the tissues within the shunt and stent were analvzed with Kruskal Wallis test. Results Restenosis of TIPS occurred in 4 models and complete occlusion were seen in 2,while all vascular stents were patent and coated with a thin layer of intimal tissueElectron micmscopic results showed that the tissues in restenotic TIPS were loose and with more extra matrix and fibers.and less smooth muscle,fibroblastic and myofibroblastic cells with different and irregular shape and rich secretory granules.The tissues in patent,TIPS contained more extra fibers,smooth muscle and fibmblastic cells with normal organdie.The intimal tissues in vascular stent contained more fibers and fibroblasts cells.less smooth muscle cells.On immunohistoehemical staining,the tissues in restenotlc and Datent TIPS as well as the intimal tissues in vascular stent had strong positive expression for anti-SMCactin-α.the expression were gradually weakened for PCNA,the intimal tissues in vascular stent had a strong positive expression for vimentin,while the expression of the tissues in restenotic and patent TIPS were weakened gradually.For myoglobulin,the tissues in restenotic TIPS had weakly positive expression,the expression in patent TIPS and vascular stent were almost negative. Western blot results for TGF-β showed that the absorbance ratios of the intima tissues in vascular stent,normal vascular tissues,normal liver tissues.the tissues in restenotic and patent TIPS were 0.23,0,0,0.57 and 0.30 respectively,and they were significantiy different (H=27.8,P＜0.01).Conclusions The tissues in restenotic TIPS mainly contain proliferated SMCs which have positive expression for anti-SMC-actin-α,strong proliferation and movement but unstability.The tissues in patent TIPS and intimal tissues in Vascular stent mainly contain fibroblastie cells which have positive expression for vimentin and stability.

Exploration of CHENG Men-xue's academic thoughts about ‘pathemas in meridians and collaterals’ / 中华中医药杂志

‘Pathemas in meridians and collaterals’, a new word in stroke, is put forward by CHENG Men-xue. He emphasizes that pathemas in meridians and collaterals plays an important part in syndrome differentiation of stroke. Attention should be paied to meridians and collaterals when we treat stoke. Drugs with function of dispelling wind and removing obstruction in the meridians should be used in the whole process of the stroke.

Expression of PDGF and growth of VSMC after mechanical injury and exposure to autologous serum / 介入放射学杂志

Objective To investigate the growth and expression of PDGF of VSMCs in response to stimulation of autologous serum and mechanical injury. Methods An vitro model simulating the condition as possible as that after PTA.PDGF of every medium sample from every group was detected by ELISA,and the values of MTT of every cellular sample was measured by MTT to show the growth and proliferation of every group. Results After stimulation by autologous serum and mechanical injury,SMCs of the experimental group showed the value of MTT increasing,but SMCs in control group reached on 3rd day.At the same time,the expression of PDGF also increased gradually,obtaining peak gradually up to peak on day 4/5 nearly 2.0-fold as much as that of SMCs in the control group. Conclusions After on the 5th day,stimulation with autologous serum and mechanical injury,VSMCs of rabbit showed the stronger ability of growth/proliferation,and autocrine of PDGF also increased gradually,reaching peak on 4-5 d,probobly simulating to those in vivo.