PURPOSE: A common finding of carotid artery on magnetic resonance angiograms(MRAs) is a signal dropout along the posterior wall of carotid bulb due to reverse flow. The purpose of this study is to evaluate variable flow patterns on bifurcated carotid arterial phantoms using steady-state flow. MATERIALS AND METHODS: We designed phantoms of a bifurcated carotid artery with acrylic materials. Flow patterns were evaluated with axial and coronal imaging of MRA(2D-TOF, 3D-TOF), color Doppler imaging, and computational fluid dynamics (CFD) within the phantoms constructed of an automated closed-type circulatory system filled with 4% sugar solution. These findings were compared with findings obtained from normal volunteers. RESULTS: Axial 3D-TOF MRA images exhibited closer resemblance to the contour of the inner wall of phantoms when compared to coronal 2D-TOF MRA imaging. However, 2D-TOF MRA showed good contrast difference of signal intensities between forward flow area and reverse flow area. Dark zones with reduced signal intensities due to reversed flow were separated from the outer wall of the internal and external carotid arteries by a thin layer of forward flow along the wall on the source slice image of MRA. The general hemodynamics of the phantoms on MRA were identical to hemodynamics on color Doppler imaging and CFD. The results obtained with the phantoms matched the findings on normal volunteers. CONCLUSION: Although representations of bifurcated carotid arterial phantoms on axial 3D-TOF MRA were excellent if ideally desinged, the zone of reversed flow could be a significant factor in creating distorted image when the zone of reversed flow contacted directly with curved or deformed arterial wall.
Carotid Arteries ; Carotid Artery, External ; Healthy Volunteers ; Hemodynamics ; Humans ; Hydrodynamics ; Magnetic Resonance Angiography* ; Patient Dropouts

OBJECTIVETo investigate the role of Notch1 in the proliferation, migration and invasion of gastric cancer cells.

METHODSNotch1 expression was detected by RT-PCR and Western blot in four gastric cancer cell lines(SGC-7901, BGC-823, MKN-45 and MKN-28). The RNAi segments targeting Notch1 were designed and transfected into cell lines with the highest level of Notch1. The transcription and translation level of Notch1 expression was detected by real-time PCR and Western blot. The proliferation of transfected cells were determined by CCK8 test. Meanwhile, the migration and invasive ability of transfected tumor cells were detected by Transwell test.

RESULTSGastric cell line BGC-823 was selected with the highest expression of Notch1 at both mRNA level and protein level. The expression of Notch1 was significantly reduced after the transfection. The CCK8 test showed the growth rate was significantly reduced in RNAi group after two days(F=4.644, P=0.046). In migration test, the number of cells crossing through chambers in RNAi group(30.1±3.1) was significantly lower than that in the negative control group(44.5±3.2) and in the mock group(46.1±2.6)(P<0.05). In invasion test, the number of cells crossing through chambers in RNAi group(22.9±4.5) was also significantly lower than that in the negative control group (37.3±4.2) and in the mock group (37.8±3.7)(P<0.05).

CONCLUSIONDown-regulation of Notch1 inhibits the proliferation and reduces the ability of migration and invasion in gastric cell line BGC-823, suggesting that Notch1 may play an important role in the gastric carcinogenesis and metastasis.

Cell Line, Tumor ; Cell Movement ; Cell Proliferation ; Down-Regulation ; Humans ; Neoplasm Invasiveness ; RNA Interference ; RNA, Messenger ; Real-Time Polymerase Chain Reaction ; Receptor, Notch1 ; genetics ; Reverse Transcriptase Polymerase Chain Reaction ; Stomach Neoplasms ; Transfection

PURPOSE: It has been suggested that an ulceration or hemorrhage within an atheroma on a stenotic carotid artery is a clinically important cause of transient ischemic attack(TIA). In previous studies, due to its inherent signal loss by static or turbulent flow, magnetic resonance angiography(MRA) proved to be an unreliable methed for the evaluation of subtle changes of ulceration. To improve the detectability of the ulceration within atheroma, avascular phantom was filled with gadolinium solution of various concentrations during various MR sequences. MATERIALS AND METHODS: Several vascular phantoms made of elastic silicon mimicking an ulcerated stenotic internal carotid artery(ICA) were constructed, and gadolinium solution of different concentrations (1:1000 and 1:200 of Gd-DTPA) and distilled water were introduced into the vascular phantoms using a computerized pulsatile pump. To evaluate maximum intensity projection(MIP), multiple planar reconstruction(MPR) and source images, axial and coronal images of MRA with 2D-TOF(time of flight) and 3D-TOF were reviewed. Each image of various sequences was compared with plain X-ray films of each phantom filled with barium. RESULTS: On all MR suquences, the images of the phantom of the normal carotid bifurcation were superior to the images of ulcerated and stenotic phantoms. MPR and MIP were the optimal image for detecting and defining ulceration and stenosis. Better quality images were obtained when a higher concentration of Gd-DTPA was used and when the 3D-TOF technique instead of the 2D-TOF technique was applied. CONCLUSION: This study reveals that a combination of higher concentration gadolinium with MPR and MIP on 3D-TOF technique could be optimal for the evaluation of ulceration and/or stenosis at the bifurcation of the carotid artery.
Barium ; Carotid Arteries ; Carotid Artery, Internal* ; Constriction, Pathologic ; Gadolinium ; Gadolinium DTPA ; Hemorrhage ; Magnetic Resonance Angiography* ; Plaque, Atherosclerotic ; Silicones ; Ulcer* ; Water ; X-Ray Film

PURPOSE: The most important factor discrediting the reliability of MRAs is the overestimation of the degree of stenosis in the internal carotid artery(ICA). The purpose of this study is to evaluate the second aryhemodynamics and the cause(s) for the overestimation of the degree of variable stenotic phantoms of the carotidartery using steady-state flow on MRAs. MATERIALS AND METHODS: Using scrylic materials, normal and variable stenotic phantoms of the bifurcated carotid artery were constructed (40% and 65%). Flow patterns were evaluated with axial and coronal imaging of MRAs (2D-TOF and 3D-TOF) and DSAs of phantoms constructed from an automated closed-type circulatory system filled with 10% glucose solution. These findings were then compared with those obtained from CFD. RESULTS: 3D-TOF axial MRA of asymmetrically 40 percent stenotic phantom revealed 40 percent stenosis identical to the stenotic region of phantoms with continued poststenotic signal loss, whereas 3D-TOFzsial MRA of symmetrically 65 percent stenotic phantom showed markedly decreased signal intensity at the poststenotic segment resembling occlusion. Source image of 2D-TOF coronal MRA showed redistribution (from theinternal to external carotid artery side) of the central axis of inflow depending upon the degree of stenosis ofthe ICA ; this redistribution can be a cause of the decreased signal at the poststenotic segment, due to a reduced volume of flow through the stenotic segment. The general hemodynamics of the variable stenotic phantoms on MRA were identical to the hemodynamics on DSA and CFD. CONCLUSION: Although dephasing from turbulent flow and character of maximum intensity projection (MIP) were suggested as the main cause of the decreased poststenotic signal, our study indicated that a hemodynamically redistributed central axis of inflow and reduced flow volume through stenotic channel is one of the basic factors of the decreased signal intensity ot the poststenotic segmenton MRA.
Axis, Cervical Vertebra ; Carotid Arteries ; Carotid Artery, External ; Constriction, Pathologic* ; Glucose ; Hemodynamics*

PURPOSE: To evaluate the usefulness and the accuracy of CT-discography in lumbar disc disease by analyzing the findings of CT-discogram and types of evoked pain during the procedure. MATERIALS AND METHODS: CT-discograms were retrospectively evaluated in 47 intervertebral discs of 20 patients with multilevel involvement of lumbardisc diseases. In 28 herniated discs confirmed at surgery, the findings of CT-discogram (28 disc levels/20 patients), MRI(23/16) and CT(21/15) were comparatively analysed. The type of pain after infusion of contrast mediaduring CT-discography was compared with that prior to the procedure. RESULTS: The accuracy for determining typesof the herniated lumbar disc when compared with postoperative results was 96.4%(27 discs/28 discs) in the CT-discogram, 82.6%(19 discs/23 discs) in MRI and 71.4%(15 discs/21 discs) in the CT scan. Pains encountered during discography were radiating pain in 12 discs and back pain in 24 discs. CT-discography was especially helpful in 10 patients with multilevel involvement of the lumbar disc diseases to evaluate the exact location of diseased disc(s) that provoked the pain. CONCLUSION: CT-discography is a highly accurate method in diagnosis ofthe herniated lumbar intervertebral discs and is very useful in determining the precise location related to the development of pain in such cases.
Back Pain ; Diagnosis ; Humans ; Intervertebral Disc ; Intervertebral Disc Displacement ; Magnetic Resonance Imaging ; Retrospective Studies ; Spine ; Tomography, X-Ray Computed

Most patients with differentiated thyroid cancer have a good prognosis after radioiodine-131 therapy,but a small number of patients are insensitive to radioiodine-131 therapy and even continue to develop disease.At present,some targeted drugs can improve progression-free survival in patients with radioactive iodine-refractory differentiated thyroid cancer(RAIR-DTC),such as sorafenib and levatinib,have been approved for the treatment of RAIR-DTC.However,due to the presence of primary and acquired drug resistance,drug efficacy in these patients is unsatisfactory.This review introduces the acquired drug resistance mechanism of sorafenib in the regulation of mitogen-activated protein kinase(MAPK)and phosphatidylinositol-3-kinase(PI3K)pathways and proposes related treatment strategies,in order to provide a reference for similar drug resistance mechanism of sorafenib and effective treatment of RAIR-DTC.

Objective The aim is to investigate the association between body mass index (BMI) and risk of all-cause mortality among patients with type 2 diabetes. Methods A total of 17 638 patients with type 2 diabetes registered in the management of National Basic Public Health Services in two areas of southern and northern Jiangsu were recruited. Cox proportional risk regression model was used to calculate the hazard ratio(HR) value and 95% confidence interval (95% CI) of different BMI groups in the follow-up period. Results The subjects were followed up for a total of 77 451 person-years with an average duration of 4.39 years, and 1 274 patients died during the follow-up period. The number of death in low weight group (BMI<18.5 kg/m2), normal weight group (18.5 kg/m2≤BMI<24 kg/m2), overweight (24 kg/m2≤BMI<28 kg/m2) and obese group (BMI≥28 kg/m2) were 39, 575, 484 and 176 respectively.The corresponding mortalities were 15.6%, 9.5%, 6.2% and 5.1%, respectively. Compared to normal weight group, the adjusted HR of all-cause mortality in low weight, overweight and obese group were 1.66 (95% CI: 1.20-2.30), 0.68 (95% CI: 0.61-0.77), 0.58 (95% CI: 0.48-0.68), respectively. Conclusions Low-weight patients have the highest risk of all-cause mortality compared with normal counterparts, while both overweight and obese people have a lower risk of death. Overweight and obesity may reduce the risk of all-cause mortality in type 2 diabetic patients.

BACKGROUND: Infant adipose-derived mesenchymal stem cells (ADSCs) collected from excised polydactyly fat tissue, which was surgical waste, could be cultured and expanded in vitro in this study. In addition, the collecting process would not cause pain in the host. In this study, the proliferation, reduction of senescence, anti-oxidative ability, and differentiation potential in the infant ADSCs were compared with those in the adult ADSCs harvested from thigh liposuction to determine the availability of infant ADSCs. METHODS: Proliferation was determined by detecting the fold changes in cell numbers and doubling time periods.Senescence was analyzed by investigating the age-related gene expression levels and the replicative stress. The superoxide dismutase (SOD) gene expression, adipogenic, neurogenic, osteogenic, and tenogenic differentiation were compared by RTqPCR. The chondrogenic differentiation efficiency was also determined using RT-qPCR and immunohistochemical staining. RESULTS: The proliferation, SOD (SOD1, SOD2 and SOD3) gene expression, the stemness-related gene (c-MYC) and telomerase reverse transcriptase of the infant ADSCs at early passages were enhanced compared with those of the adults’Cellular senescence related genes, including p16, p21 and p53, and replicative stress were reduced in the infant ADSCs. The adipogenic genes (PPARγ and LPL) and neurogenic genes (MAP2 and NEFH) of the infant ADSC differentiated cells were significantly higher than those of the adults’ while the expression of the osteogenic genes (OCN and RUNX) and tenogenic genes (TNC and COL3A1) of both demonstrated opposite results. The chondrogenic markers (SOX9, COL2 and COL10) were enhanced in the infant ADSC differentiated chondrogenic pellets, and the expression levels of SODs were decreased during the differentiation process. CONCLUSION Cultured infant ADSCs demonstrate less cellular senescence and replicative stress, higher proliferation rates, better antioxidant defense activity, and higher potential of chondrogenic, adipogenic and neurogenic differentiation.

OBJECTIVETo study whether the porcine alpha1, 3 galactosyltransferase gene siRNA targeted heterozygous hepatocyte negatively expresses GT mRNA and resists to the cytotoxicity of nature antibody in human serum.

METHODSThe porcine alpha1, 3 galactosyltransferase gene siRNA targeted vector (pPNTloxPGTsiRNA) were construct with pPNTloxPGT and pMXSV/U6 vector. Positive-negative selection was used to produce a heterozygous pPNTloxPGTsiRNA knockout (+/-) clone. The GT mRNA expressions were detected with northern blot. Complement-mediated NAb cytotoxicity after incubation of hepatocytes with NAbs and complement was determined using 3- (4, 5-dimethylthiazol-2-yl)-5-(3-carboxymethyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium(MTS, tetrazolium salt) colorimetric assay.

RESULTSThe pPNTloxPGTsiRNA targeted porcine hepatocyte (+/-) negative express GT mRNA. Only 14% to 18% cytotoxicity can be detected at the highest serum concentration. The pPNTloxPGT targeted porcine hepatocyte (+/-) express GT mRNA just as the wild type porcine cells and the cytotoxicity are 77% to 83%.

CONCLUSIONThe porcine a1, 3 galactosyltransferase gene siRNA targeted heterozygous hepatocyte (+/-) negative express GT and resisted to nature antibody in human serum.

Animals ; Cells, Cultured ; Cloning, Molecular ; Cytotoxicity, Immunologic ; genetics ; Galactosyltransferases ; biosynthesis ; genetics ; Gene Silencing ; Gene Targeting ; methods ; Hepatocytes ; cytology ; metabolism ; Heterozygote ; Immune Tolerance ; genetics ; Killer Cells, Natural ; immunology ; Mutation ; RNA, Small Interfering ; biosynthesis ; genetics ; Swine ; Transfection

OBJECTIVETo discuss the application of MRI in indirect temporomandibular joint injury without condylar fracture.

METHODSMRI examination on temporomandibular joint was conducted in 28 patients with indirect injury to temporomandibular joint without condylar fracture. The scanning sequence included T(1)WI, PDWI on oblique sagittal section at both open and closed mouth positions, and T(1)WI, T(2)WI on oblique coronal section. The MRI appearance was analyzed by 2 senior radiologists.

RESULTSAmong the 56 temporomandibular joints of 28 patients, 35 joints exhibited pathological changes on MRI, in which there were 9 bone injuries, 21 articular disc dislocation, 24 intracapsular hematocele and hydrops.

CONCLUSIONSMRI can clearly reveal bone injury, articular disc dislocation as well as articular capsule abnormality in the indirect injury of temporomandibular joint without condylar fracture. It is highly advocated in clinical use.

Adolescent ; Adult ; Aged ; Child ; Female ; Humans ; Magnetic Resonance Imaging ; Male ; Maxillofacial Injuries ; diagnosis ; Middle Aged ; Temporomandibular Joint ; injuries