In recent years,endovascular intervention therapy has gained popularity due to its advantages of minimal trauma and quick recovery,and become an essential method for treating cerebrovascular diseases.As a crucial surgical instrument in interventional therapy,catheters often require precise control of their tips to navigate through tortuous positions.Traditional catheters have shortages of fixed tip shapes,limited proximal torque transmission,and difficulty of manipulation,increasing the risk of complications during interventional procedures and prolonging surgical exposure time.With the rapid development of materials science and engineering,steerable catheter systems have become the spotlight of interventional physicians,making precise"bend control"possible.This article systematically explained the classification of steerable catheter systems,focusing on their application in neurointerventional therapy,and provided an outlook on the future development of steerable catheters.

Objective To evaluate the effect of micronutrient selenium on atopic dermatitis-like skin lesions in mice.Methods After 4-week feed with forages lacking selenium,40 BALB/c mice were randomly and equally divided into 4 groups:selenium deficiency group fed with forages containing 0.01 mg/kg selenium for 4 weeks,normal selenium supplementation group fed with forages containing 0.25 mg/kg selenium for 4 weeks,excessive selenium supplementation group fed with forages containing 3.00 mg/kg selenium for 4 weeks,and control group fed with forages containing 0.25 mg/kg selenium for 4 weeks.Then,atopic dermatitis-like skin lesions were induced by dinitrochlorobenzene (DNCB) in the mice in sensitized groups,including the selenium deficiency group,normal selenium supplementation group and excessive selenium supplementation group.During sensitization,the severity of dermatitis in mice was monitored.Three weeks after the sensitization,the total plasma IgE level and inflammatory cell count in whole blood were measured.Skin tissues from the back of mice were subjected to histopathological examination and the selenium level was detected.Statistical analysis was carried out by one-way analysis of variance for comparisons of IgE levels and cell counts among different groups,as well as by Pearson correlation analysis and linear regression analysis for analyzing the correlation of various indices with the selenium level.Results Six days after the sensitization,the dermatitis severity scores were significantly higher in the sensitized groups than in the control group (On day 6,8,11,13,15 and 18 after the sensitization,F =44.897,76.622,114.866,33.352,28.605 and 11.271 respectively,all P ＜ 0.01).On day 11 after the sensitization,the dermatitis severity score was significantly higher in the excessive selenium supplementation group than in the selenium deficiency group and normal selenium supplementation group (both P ＜ 0.05).Compared with the control group,obvious pathological changes of dermatitis were observed in the sensitized mice,but there was no significant difference in the number of inflammatory cells in skin lesions among the 3 sensitized groups (all P ＞ 0.05).The inflammatory cell count in whole blood and total plasma IgE level in the sensitized mice increased along with the increase of dietary selenium levels,and the excessive selenium supplementation group showed higher total plasma IgE level ([167.17 ±8.49] μg/L) compared with the selenium deficiency group ([124.78 ± 5.32] μg/L,t =3.919,P ＜ 0.05),normal selenium supplementation group ([132.61 ± 4.71] μg/L,t =3.222,P ＜ 0.05) and control group ([109.13 ± 0.79] μg/L,t =6.485,P ＜ 0.05).The selenium level in the skin tissues of sensitized mice was positively linearly correlated with the total plasma IgE level (r =0.579,P ＜ 0.001),whole-blood white blood cell count (r =0.414,P ＜ 0.05),neutrophil count (r =0.439,P ＜ 0.05),lymphocyte count (r =0.417,P ＜ 0.05)and eosinophil count (r =0.505,P ＜ 0.01).Conclusion Different dietary selenium levels showed different effects on the severity of dermatitis in mice,and more severe dermatitis occurred in the excessive selenium supplementation group.

Objective To evaluate inhibitory effect of Chlamydia trachomatis plasmid-encoded protein pORF5 on HeLa cell apoptosis induced by tumor necrosis factor-alpha(TNF-α). Methods The recombinant lentiviral expression vector containing pORF5 gene and helper plasmids were co-transfected into 293T cells to prepare the recombinant lentivirus. Then, the lentivirus particles were collected and concentrated, and used to infect HeLa cells. Flow cytometric screening identified stable pORF5-expressing HeLa (pORF5-HeLa) cells. Meanwhile, the empty plasmid was transfected into HeLa cells to prepare control HeLa cells. The two cell lines were both divided into two subgroups to be treated with 20μg/L TNF-αand fresh culture medium respectively for 6 hours. Then, Hoechst 33258 staining was performed to observe morphological changes of apoptotic cells, flow cytometry to detect cell apoptosis, real-time PCR to measure the mRNA expression of Caspase3, Bax and Bcl-2, and Western blot analysis to determine the protein expression of Bax and Bcl-2. Results After 6-hour treatment with TNF-α, Hoechst 33258 staining showed variable degrees of karyopyknosis and karyorrhexis, and highly-refractive blue apoptotic bodies in the pORF5-HeLa cells and control HeLa cells. The pORF5-HeLa cells and control HeLa cells both showed significantly higher apoptosis rate in the treated subgroup than in the untreated subgroup (pORF5-HeLa cells:35.5%± 4.5%vs. 9.5%± 1.5%, t=13.53, P<0.01;control HeLa cells:63.6%± 5.8%vs. 7.9%± 0.9%, t=32.36, P<0.01). Compared with treated control HeLa cells, treated pORF5-HeLa cells showed significant decreases in mRNA expression of Bax(72.8%)and Caspase 3(84.5%)(t = 35.29, 42.25, respectively, both P < 0.01), as well as in Bax protein expression(t = 17.58,P < 0.01), but significant increases in Bcl-2 mRNA and protein(6.8 times)expression(t = 87.12, 18.93, respectively, both P <0.01). Conclusion pORF5 plasmid protein can inhibit TNF-α-induced HeLa cell apoptosis likely by increasing the expression of anti-apoptotic protein bcl-2 and decreasing the expression of pro-apoptotic proteins Caspase-3 and Bax.

Objective To study the correlations among lumbosacral anatomical structure variations and herniation of intervertebral disc.Methods Through analyzing lumbar CT images of 684 patients with lumbocrural pain between 15 to 24 years old, the anatomical variations of spondylolysis, scoliosis deformity, lumbosacral transitional vertebra, subfissure, lumbosacral angle and others (including vertebral muscles beside, spines, transverse process on both sides) were observed, and the correlations among these anatomical variations and herniation of intervertebral disc were analyzed.Results The correlations among these above mentioned anatomical variations and herniation of intervertebral disc were 93.6%,92.3%,87.5%,81.3%,72.1%,53.3% respectively.In 91.4% of patients, the lumbosacral anatomical structure variations suffered herniation of intervertebral disc at the same time.But only 36.2% of patients suffered herniation of intervertebral disc without lumbosacral anatomical structure variations.Conclusion Lumbosacral anatomical structure variation is the main reason of herniation of intervertebral disc on teenagers.CT examination,which can reflect the correlation between them.

Objective To investigate the expression of syntaxin 8(STX8)in glioma and its clinical signif-icance. Methods Specimens of glioma were collected from 57 patients at Beijing Renhe Hospital from May 2013 to December 2015. 57 pieces of glioma tissue were used as a study group ,12 of which were Ⅰ+ Ⅱ(low grade) and the rest 45 were Ⅲ+Ⅳ;normal brain tissues from 15 individuals were used as a control group. Real-time PCR,immunohistochemistry,and Western blot were used to detect expression of STX8. Results As compared with the normal brain tissue ,the mRNA expression of STX8 was significantly increased in glioma tissue ,with a relative expression volume of 1.6855 ± 0.07124 in low grade and 2.8207 ± 0.0692 in high grade tissues,there was significant differences between the two groups;and the difference was also significant as compared with the control group(P < 0.05). The results of immunohistochemistry showed that the expression of STX8 was higher in glioma tissue than in normal tissue. Western Blot showed that the expression of STX8 protein was significantly higher in glioma than in normal tissue(P<0.05);the relative expression volume of STX8 was 2.271 ± 0.1621 in low grade tissue and 4.937 ± 0.1851 in high grade tissue,with a significant difference between the two groups;the difference was also significant as compared with the control group(P<0.05). The correlation analysis showed that higher STX8 expression in glioma was not significantly related to gender,age and pathological types,but there was a significant difference between pathological stages. Conclusion STX8 has abnormal high expression in glioma,which may be closely related with the occurrence and development of glioma.

BACKGROUND:It has been proved that miR-34a plays an inhibitory role in the growth of lung cancer stem cels, but the underlying mechanism remains unclear.
OBJECTIVE:To explore the inhibitory effect of miR-34a on lung cancer stem celsand the underlying mechanism.
METHODS:The CD133+lung cancer stem cels were separated from lung cancer A549 cel lines using magnetic activated cel sorting method. And miR-34a-overexpressing CD133+lung cancer stem cels were established by liposome transfection technology. Besides,the targeted relationship between miR-34a and Notch1 was analyzed by the dual-luciferase reporter. Afterwards, Notch1 silencing was performed by gene knockout, and its effect on lung cancer stem cels was determined.
RESULTS AND CONCLUSION:After sorted and detected by immunomagetic selection and flow cytometry assay respectively, a high rate of CD133+lung cancer stem cel was obtained. And qRT-PCR detected that the expression level of miR-34a in CD133+lung cancer stem cels was significantly lower than that in CD133-lung cancer stem cels. Moreover, miR-34a-overexpressing CD133+lung cancer stem cels were successfuly constructedandmiR-34a significantly inhibited proliferation and induced apoptosis of lung cancer stemcels. Dual-luciferase reporter assay indicated that Notch1 mRNA was a target of miR-34a. In addition, Notch1 silencing obviously inhibited proliferation and induced apoptosis of lung cancer stem cels. These findings suggest that miR-34a can inhibite lungcancer stem celsviathe Notch1 signaling pathway.

OBJECTIVETo investigate the effect of short and long term exposure to SiO2 nanoparticles on microRNA expression level in human bronchial epithelial cells(16HBE cells).

METHODSThe 16HBE cells were exposed to 5, 10, 15, 20, 25, 30 and 40 μg/ml SiO2 nanoparticles for 24 h to detect the cell viability by using CCK-8 assay. The inhibition rate of proliferation activity and half inhibitory concentration (IC50) were calculated. The 16HBE cells were exposed to 10 μg/ml SiO2 nanoparticles for 10 and 30 generations, named P10 and P30, and the control P0 was set. The cells were treated with SiO2 nanoparticles at 0, 1/4 IC50, 1/2 IC50 and IC50 concentration and μm-SiO2 at IC50 concentration for 24 h, and the control serum-free culture medium was set. Agilent miRNAs microarray chip was used to screen differentially expressed miRNAs in P10, P30 and P0 groups. The expression level of miRNA was detected by reverse transcription fluorescence quantitative polymerase chain reaction (qRT-PCR).

RESULTSThe inhibition rate of proliferation activity of 5, 10, 15, 20, 25,30,40 μg/ml group were (-3.33 ± 3.80)%, (20.40 ± 11.73)%, (39.08 ± 5.53)%, (55.10 ± 5.78)%, (66.42 ± 9.60)%, (71.67 ± 7.34)%, (81.43 ± 5.37)%, respectively; F=129.11, P<0.001. The IC50 (95%CI) was 18.35 (15.82-20.72) μg/ml. The expression level of miRNA-494-3p in P0, P10 and P30 were 1.00, 0.45 ± 0.08, 0.28 ± 0.07, respectively; F=60.77, P<0.001. miRNA-19a-3p were 1.00, 2.27 ± 0.45, 1.06 ± 0.19, respectively; F=30.05, P<0.001. miRNA-148b-3p were 1.00, 1.78 ± 0.29, 0.88 ± 0.19, respectively; F=30.23, P<0.001. Compared to control group, the expression level of miRNA-494-3p in 5, 10, 20 μg/ml SiO2 nanoparticles groups and 20 μg/ml μm-SiO2 group were 0.99 ± 0.04, 1.38 ± 0.19, 2.13 ± 0.14, 0.81 ± 0.25, respectively; F=57.03, P<0.001. miRNA-19a-3p were 0.91 ± 0.03, 1.12 ± 0.03, 0.53 ± 0.01, 0.86 ± 0.01, respectively; F=408.78, P<0.001. miRNA-148b-3p were 0.95 ± 0.02, 1.22 ± 0.00, 0.54 ± 0.02, 1.15 ± 0.04 respectively; F=264.14, P<0.001.

CONCLUSIONShort and long term exposure to SiO2 nanoparticles can affect the expression level of miRNAs in 16HBE cells. The expressions of miRNA-494-3p after long and short period exposure are different.

Cells, Cultured ; Epithelial Cells ; drug effects ; metabolism ; Humans ; MicroRNAs ; metabolism ; Nanoparticles ; chemistry ; Oligonucleotide Array Sequence Analysis ; Silicon Dioxide ; chemistry

OBJECTIVETo study the effect of silicon dioxide nanoparticles on the expression and promoter region CpG islands methylation of (Poly [ADP-ribose] polymerase 1, PARP-1) gene in human HaCaT Cell.

METHODSHaCaT Cells were treated with nm-SiO₂at 0, 2.5, 5 and 10 µg/mL and micro-SiO₂at 10 µg/ml for 24 h and DAC treatment was given at 10 µg/ml group for 48 h. Real-time PCR and western blot assay was used to detect the expression of PARP-1 mRNA and protein. BSP (Bisulfite Pyrosequence, BSP) assay was used to detect the promoter region CpG islands methylation status of PARP-1 gene.

RESULTSAfter exposure to nano-SiO₂particles, compared to CTRL group, the mRNA and protein expression of PARP-1 in micro-SiO₂and 2.5 µg/ml group unchanged, but he mRNA and protein expression of PARP-1 in 5, 10 µg/ml as well as DAC group was down-regulated and there are statistical significance between CTRL group and 5, 10 µg/ml as well as DAC group and the PARP-1 promoter region CpG islands showed methylation.

CONCLUSIONnano-SiO₂can down-regulate PARP-1 expression in HaCaT Cell and this is associated with the change in the methylation of PARP-1 gene promoter region CpG islands induced by nano-SiO₂particles.

Cell Line, Tumor ; CpG Islands ; DNA Methylation ; Humans ; Nanoparticles ; adverse effects ; Poly (ADP-Ribose) Polymerase-1 ; Poly(ADP-ribose) Polymerases ; metabolism ; Promoter Regions, Genetic ; RNA, Messenger ; metabolism ; Silicon Dioxide ; adverse effects

Objective To explore the diagnostic significance of CT and MRI in dermatofibrosarcoma protuberans.Methods Analyze the CT and MRI images of 16 cases which were confirmed as dermatofibrosarcoma protuberans by pathology.The medical imaging features of dermatofibrosarcoma protuberans were summarized.In the total 16 cases(including 6 male cases,10 female cases),15 cases had suffered from dermatofibrosarcoma protuberans for more than 1 year, 11 cases for more than 5 years, and 9 cases had history of recurrence.Results On MRI, the mass was slightly hypointense on T 1 WI, inhomogeneously hyperintense on T 2 WI with inhomogenous enhancement.The diameters of mass were less than 5 cm in 3 cases,and were more than 5cm in 13 cases.Fifteen cases had clear demarcation between the masses and their adjacent muscles , 7 cases had “suspension sign” in shapes, 10 cases had “sub-nodules outward” features at the edge of the tumors , 12 cases had “multinodular” features inside the tumor , and 8 tumors grew into the surrounding fat layer like roots.Conclusion Dermatofibrosarcoma protuberans can be diagnosed accurately based on the features displayed on CT and MRI.

OBJECTIVETo apply the classic leakage integrate-and-fire models, based on the mechanism of the generation of physiological auditory stimulation, in the information processing coding of cochlear implants to improve the auditory result.

METHODSThe results of algorithm simulation in digital signal processor (DSP) were imported into Matlab for a comparative analysis.

RESULTSCompared with CIS coding, the algorithm of membrane potential integrate-and-fire (MPIF) allowed more natural pulse discharge in a pseudo-random manner to better fit the physiological structures.

CONCLUSIONThe MPIF algorithm can effectively solve the problem of the dynamic structure of the delivered auditory information sequence issued in the auditory center and allowed integration of the stimulating pulses and time coding to ensure the coherence and relevance of the stimulating pulse time.

Acoustic Stimulation ; Algorithms ; Cochlear Implantation ; Cochlear Implants ; Humans ; Membrane Potentials ; Models, Theoretical ; Signal Processing, Computer-Assisted ; Speech Discrimination Tests