ABSTRACT: Polyethylene glycol-grafted polyethylenimine (PEG-g-PEI) which was functionalized with a neuroblastoma cell-specific ligand, the GD2 single chain antibody (scAb(GD2)), was synthesized in order to effectively deliver Bcl-2 siRNA into neuroblastoma cells. This polymer was complexed first with superparamagnetic iron oxide nanoparticle (SPION) to get a MRI-visible targeted non-viral vector (scAb(GD2)-PEG-g-PEI-SPION) and then with Bcl-2 siRNA to form nanoparticles showing low cytotoxicity. The targeting capacity of scAb(GD2)-PEG-g-PEI-SPION was successfully verified in vivo and in vitro by magnetic resonance imaging. The single chain antibody encoded targeted polyplex was more effective in transferring Bcl-2 siRNA than the nontargeting one in SK-N-SH cells, a human neuroblastoma cell line, resulting in a 46.34% inhibition in the expression of Bcl-2 mRNA. Consequently, a high level of cell apoptosis up to 50.76% and a significant suppression of tumor growth were achieved, which indicates that scAb(GD2)-PEG-g-PEI-SPION is a promising magnetic resonance imaging-visible non-viral vector for targeted neuroblastoma siRNA therapy and diagnosis.
International Journal of Nanomedicine 01/2012; 7:3319-32. · 3.13 Impact Factor
ABSTRACT: To create far-red fluorescence protein reporter gene mKate2 lentivirus, label human liver cancer cell line HepG2 with lentivirus and explore the feasibility of in vitro fluorescence imaging of labeled tumor cells so as to provide experimental rationales for in vivo fluorescence tumor imaging.
mKate2 gene was amplified from pmKate2-N plasmid. Then the fragment was inserted into the lentivirus expression vector pLenti6.3/V5-DEST. The expression plasmids pLenti6.3-mKate2 and the packaging plasmids were cotransfected into 293T cells. The biological titer of lentivirus was determined. HepG2 cells were infected with mKate2 lentivirus at a MOI (virus multiplicity of infection) of 6 for 96 hours. The infection efficiency was assayed through fluorescence microscope and fluorescent-activated cell scanning (FACS). And 2 × 10(6) mKate2-HepG2 cells were collected for fluorescence imaging through an optical imaging system. And the optimal imaging parameters were determined.
DNA sequencing analysis confirmed that mKate2 gene sequence was correct and there was no mutation or deletion. The biological titer of produced mKate2 lentivirus was 1.6 × 10(6) TU/ml. At 96 hours after mKate2 lentivirus infection, fluorescence microscope showed that mKate2 was expressed in a large percentage of cells. FACS assay showed that the mKate2 positive rate was 93.8% ± 0.4%. Excitation light 530 ± 15 nm and emission light 710 ± 28 nm were the optimal imaging parameters for mKate2-HepG2 cells.
Lentivirus can mediate efficiently the mKate2 reporter gene labeling of human liver cancer cell line HepG2. The mKate2-labeled HepG2 cells can be detected through in vitro fluorescence imaging. Further tracing studies of in vivo tumor fluorescence imaging are technically feasible.
Zhonghua yi xue za zhi 05/2011; 91(19):1344-7.
ABSTRACT: The objective of this study was to evaluate the performance of 320-row multi-detector CT (MDCT) in the detection and grading of esophageal varices and to evaluate the ability of MDCT in predicting the risk of hemorrhage in comparison with upper endoscopy in patients with portal hypertension.
A total of 69 patients, with clinically confirmed portal hypertension, underwent epigastric triphasic enhancement scans using 320-row MDCT 1 weeks or less before upper endoscopies were performed. Two blinded abdominal imagers retrospectively interpreted all CT images to detect the presence of esophageal varices and divided EV into large EV (≥ 5 mm) and small EV (< 5 mm). The correlation between CT measurements and endoscopic grading was assessed by kappa values. With endoscopy as standard, the sensitivity, specificity, accuracy, positive predictive value and negative predictive value of the two radiologists in detection of EV were calculated. Correlations between CT measurements of varix size and red color sign were assessed by correlation analysis.
Of the total of 69 patients, 56 patients had esophageal varices, 41 had large EV, and 15 had small EV according to the endoscopic findings. MDCT showed an excellent interobserver reliability with regard to the diagnosis of the EV (k = 0.94). Agreement between CT and endoscopy with regard to the grading of EV were excellent (k = 0.77). The sensitivity, specificity, accuracy, positive predictive value and negative predictive value of radiologist 1 in the detection of EV was 95%, 69%, 87%, 93% and 75% respectively; the sensitivity, specificity, accuracy, positive predictive value and negative predictive value of radiologist 2 in the detection of EV was 93%, 77%, 87%, 95% and 71%, respectively. The sensitivity, specificity, accuracy, positive predictive value and negative predictive value of the two radiologists in the detection of large EV was 95%, 100%, 97%, 100% and 93%, respectively. CT variceal grading showed a strong correlation with endoscopic grading for both observers (P < 0.01). Correlations between CT measurements of varix size and red color sign were significant in both radiologists with a correlation coefficient r of 0.731 for radiologist 1 (P < 0.01) and 0.718 for radiologist 2 (P < 0.01).
320-row MDCT is useful for the detection and grading of EV, and it is useful in evaluation of EV for predicting a risk of hemorrhage.
Zhonghua yi xue za zhi 11/2010; 90(41):2911-5.
ABSTRACT: Gastric varices (GVs) are a major cause of gastrointestinal bleeding in patients with portal hypertension. Few studies have evaluated GVs with multidetector row computed tomography (MDCT).
To assess the diagnostic performance of MDCT in detecting GVs and revealing variceal hemodynamic changes in patients with cirrhosis.
A total of 127 consecutive cirrhotic patients who underwent both liver MDCT and esophagogastroduodenoscopy (EGD) were analyzed retrospectively. Two independent radiologists reviewed MDCT images for the detection of GVs. The variceal hemodynamic changes were assessed by the 2 radiologists in consensus on MDCT portography.
On the basis of EGD, of the 127 patients, 36 had GVs (28.4%), including small GVs in 15 patients and large GVs (>or=5 mm) in 21 patients. In detecting and grading GVs, there were moderate agreements (kappa value: 0.514 to 0.563) between MDCT and EGD, but in differentiating large varices requiring prophylactic therapy, a substantial agreement (kappa value: 0.804 for radiologist 1 and 0.796 for radiologist 2) was found. For radiologist 1, the sensitivity, specificity, accuracy, and positive and negative predictive values of MDCT for the identification of large GVs were 85.7%, 96.2%, 94.5%, 81.8%, and 97.1%, respectively; whereas for radiologist 2, they were 81.0%, 97.2%, 94.5%, 85.0%, and 96.3%, respectively. In evaluating the afferent and efferent veins of varices, the sensitivity, specificity, accuracy, and positive predictive value of MDCT portography were more than 80.0%.
MDCT is an effective screening tool for differentiating large GVs and revealing the afferent and efferent veins of varices in patients with cirrhosis.
Journal of clinical gastroenterology 11/2009; 44(5):e108-15. · 2.21 Impact Factor