Search tips
Search criteria

Results 1-25 (68)

Clipboard (0)

Select a Filter Below

more »
Year of Publication
more »
1.  Characterization of the molecular mechanisms underlying increased ischemic damage in the aldehyde dehydrogenase 2 genetic polymorphism using a human induced pluripotent stem cell model system 
Science translational medicine  2014;6(255):255ra130.
Nearly 8% of the human population carries an inactivating point mutation in the gene that encodes the cardioprotective enzyme aldehyde dehydrogenase 2 (ALDH2). This genetic polymorphism (ALDH2*2) is linked to more severe outcomes from ischemic heart damage and an increased risk of coronary artery disease (CAD), but the underlying molecular bases are unknown. We investigated the ALDH2*2 mechanisms in a human model system of induced pluripotent stem cell–derived cardiomyocytes (iPSC-CMs) generated from individuals carrying the most common heterozygous form of the ALDH2*2 genotype. We showed that the ALDH2*2 mutation gave rise to elevated amounts of reactive oxygen species and toxic aldehydes, thereby inducing cell cycle arrest and activation of apoptotic signaling pathways, especially during ischemic injury. We established that ALDH2 controls cell survival decisions by modulating oxidative stress levels and that this regulatory circuitry was dysfunctional in the loss-of-function ALDH2*2 genotype, causing up-regulation of apoptosis in cardiomyocytes after ischemic insult. These results reveal a new function for the metabolic enzyme ALDH2 in modulation of cell survival decisions. Insight into the molecular mechanisms that mediate ALDH2*2-related increased ischemic damage is important for the development of specific diagnostic methods and improved risk management of CAD and may lead to patient-specific cardiac therapies.
PMCID: PMC4215699  PMID: 25253673
2.  Preoperative Neutrophil-to-Lymphocyte Ratio Is a Predictor of Recurrence following Thermal Ablation for Recurrent Hepatocellular Carcinoma: A Retrospective Analysis 
PLoS ONE  2014;9(10):e110546.
The aim of this study is to determine the predictive value of preoperative blood neutrophil-to-lymphocyte ratio (NLR) for recurrence in recurrent hepatocellular carcinoma (RHCC) patients following thermal ablation.
Material and Methods
This retrospective study enrolled 506 RHCC patients who underwent thermal ablation from April 2006 to April 2014. The clinicopathological parameters including NLR were evaluated to identify predictors of recurrence rate after thermal ablation. A Cox multiple regression analysis was performed to determine the parameters that predicted recurrence in RHCC patients. The best cutoff value of NLR was determined with time-dependent receiver operating characteristic (ROC) curve analysis. The recurrence-free survival (RFS) rate was determined in patients with high and low NLR.
The multivariate Cox proportional hazard model analysis showed that NLR was a prognostic factor in recurrence-free survival. NLR ≥2.14 was evaluated (AUROC = 0.824; P<0.001), and 183 of 506 patients (36.2%) had a NLR of more than 2.14. During the follow-up period (12–96 months), the 1-, and 3- year recurrence rates were 20.7% and 31.6% in low NLR group, respectively. These recurrence rates were significantly less than those in the high NLR group (57.9% and 82.5%, respectively) (P<0.001). A recurrence-free survival analyses demonstrated that the RFS in the low NLR group (67.2%) was significantly higher than that in the high NLR group (13.1%) (P<0.001).
Our results show that preoperative NLR is a predictor for re-recurrence after thermal ablation in RHCC patients. Additionally, patients with NLR <2.14 have a lower recurrence rate, which may improve the clinical management of RHCC patients.
PMCID: PMC4203800  PMID: 25330319
3.  Prognostic value of preoperative absolute lymphocyte count in recurrent hepatocellular carcinoma following thermal ablation: a retrospective analysis 
OncoTargets and therapy  2014;7:1829-1835.
To investigate the prognostic value of preoperative absolute lymphocyte count (ALC) in recurrent hepatocellular carcinoma (RHCC) following thermal ablation.
Materials and methods
We retrospectively analyzed the relationship between preoperative ALC and the clinicopathologic factors and long-term prognosis in 423 RHCC patients who underwent curative thermal ablation. Correlation analysis, receiver operating characteristic (ROC) calculation, Kaplan–Meier curves, and multivariate regression were used for statistical analysis.
The median time to recurrence was 12 months for RHCC patients after thermal ablation. On multivariate Cox regression analysis, preoperative ALC was an independent risk factor for cancer recurrence, along with tumor differentiation and α-fetoprotein level. ALC ≥1.64×109/L defined by ROC calculation was associated with prolonged survival (area under the curve 0.741, P<0.001). Patients with ALC ≥1.64×109/L showed a mean survival of 20.2 months versus 11.6 months for patients with ALC <1.64×109/L (P<0.001). Patients were stratified into high and low groups according to ALC status. After excluding the basic parameters between groups, the 1- and 3-year recurrence rates in the high group were 20.9% and 29.5%, respectively, which were significantly lower than those of the low group (58.4% and 71.9%, respectively; P<0.001). The recurrence-free survival rates in the two groups analyzed by Kaplan–Meier curves were significantly different (P<0.001).
Preoperative ALC is a powerful prognostic factor for RHCC recurrence after thermal ablation, which suggests that maintaining a high ALC in RHCC patients might improve cancer outcomes.
PMCID: PMC4199816  PMID: 25336974
absolute lymphocyte count; recurrent hepatocellular carcinoma; thermal ablation; recurrence
4.  A comparative cellular and molecular biology of longevity database 
Age  2012;35(5):1937-1947.
Discovering key cellular and molecular traits that promote longevity is a major goal of aging and longevity research. One experimental strategy is to determine which traits have been selected during the evolution of longevity in naturally long-lived animal species. This comparative approach has been applied to lifespan research for nearly four decades, yielding hundreds of datasets describing aspects of cell and molecular biology hypothesized to relate to animal longevity. Here, we introduce a Comparative Cellular and Molecular Biology of Longevity Database, available at (, as a compendium of comparative cell and molecular data presented in the context of longevity. This open access database will facilitate the meta-analysis of amalgamated datasets using standardized maximum lifespan (MLSP) data (from AnAge). The first edition contains over 800 data records describing experimental measurements of cellular stress resistance, reactive oxygen species metabolism, membrane composition, protein homeostasis, and genome homeostasis as they relate to vertebrate species MLSP. The purpose of this review is to introduce the database and briefly demonstrate its use in the meta-analysis of combined datasets.
PMCID: PMC3776122  PMID: 22836712
Life span; Database; DNA repair; Protein homeostasis; Antioxidant enzymes; Stress resistance
5.  Screening Adverse Drug-Induced Arrhythmia Events Using Human Induced Pluripotent Stem Cell-Derived Cardiomyocytes and Low-Impedance Microelectrode Arrays 
Circulation  2013;128(11 0 1):10.1161/CIRCULATIONAHA.112.000570.
Drug-induced arrhythmia is the most common cause of drug development failure and withdrawal from market. This study tested whether human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) combined with a low-impedance microelectrode array (MEA) system could improve upon industry-standard, preclinical cardiotoxicity screening methods, identify the effects of well-characterized drugs, and elucidate underlying risk factors for drug-induced arrhythmia. Human iPSC-CMs may be advantageous over immortalized cell lines because they possess similar functional characteristics as primary human cardiomyocytes and can be generated in unlimited quantities.
Methods and Results
Pharmacological responses of beating embryoid bodies (EBs) exposed to a comprehensive panel of drugs at 65 to 95 days post-induction were determined. Responses of hiPSC-CMs to drugs were qualitatively and quantitatively consistent with the reported drug effects in literature. Torsadogenic hERG blockers such as sotalol and quinidine produced statistically and physiologically significant effects, consistent with patch-clamp studies on human embryonic stem cell-derived cardiomyocytes (hESC-CMs). False negative and false positive hERG blockers were identified accurately. Consistent with published studies using animal models, early afterdepolarizations (EADs) and ectopic beats were observed in 33% and 40% of embryoid bodies treated with sotalol and quinidine, respectively, compared to negligible EADs and ectopic beats in untreated controls.
We found that drug-induced arrhythmias can be recapitulated in hiPSC-CMs and documented with MEA. Our data indicate that the MEA/hiPSC-CM assay is a sensitive, robust, and efficient platform for testing drug effectiveness and for arrhythmia screening. We believe that this system holds great potential for reducing drug development costs and may provide significant advantages over current industry standard assays that use immortalized cell lines or animal models.
PMCID: PMC3855862  PMID: 24030418
stem cell; cardiomyocyte; pharmacology; arrhythmia; genomics; pharmacogenomics
6.  Role of the texture features of images in the diagnosis of solitary pulmonary nodules in different sizes 
To explore the role of the texture features of images in the diagnosis of solitary pulmonary nodules (SPNs) in different sizes.
Materials and methods
A total of 379 patients with pathologically confirmed SPNs were enrolled in this study. They were divided into three groups based on the SPN sizes: ≤10, 11-20, and >20 mm. Their texture features were segmented and extracted. The differences in the image features between benign and malignant SPNs were compared. The SPNs in these three groups were determined and analyzed with the texture features of images.
These 379 SPNs were successfully segmented using the 2D Otsu threshold method and the self-adaptive threshold segmentation method. The texture features of these SPNs were obtained using the method of grey level co-occurrence matrix (GLCM). Of these 379 patients, 120 had benign SPNs and 259 had malignant SPNs. The entropy, contrast, energy, homogeneity, and correlation were 3.5597±0.6470, 0.5384±0.2561, 0.1921±0.1256, 0.8281±0.0604, and 0.8748±0.0740 in the benign SPNs and 3.8007±0.6235, 0.6088±0.2961, 0.1673±0.1070, 0.7980±0.0555, and 0.8550±0.0869 in the malignant SPNs (all P<0.05). The sensitivity, specificity, and accuracy of the texture features of images were 83.3%, 90.0%, and 86.8%, respectively, for SPNs sized ≤10 mm, and were 86.6%, 88.2%, and 87.1%, respectively, for SPNs sized 
11-20 mm and 94.7%, 91.8%, and 93.9%, respectively, for SPNs sized >20 mm.
The entropy and contrast of malignant pulmonary nodules have been demonstrated to be higher in comparison to those of benign pulmonary nodules, while the energy, homogeneity correlation of malignant pulmonary nodules are lower than those of benign pulmonary nodules. The texture features of images can reflect the tissue features and have high sensitivity, specificity, and accuracy in differentiating SPNs. The sensitivity and accuracy increase for larger SPNs.
PMCID: PMC4153941  PMID: 25232219
Solitary pulmonary nodules (SPNs); differentiation; textures; image features
7.  Size of solitary pulmonary nodule was the risk factor of malignancy 
Journal of Thoracic Disease  2014;6(6):668-676.
The purpose of this study was to analyze the role of the sizes of solitary pulmonary nodules (SPNs) in predicting their potential malignancies.
A total of 379 patients with pathologically confirmed SPNs were enrolled in this study. They were divided into three groups based on the SPN sizes: ≤10, 11-20, and >20 mm. The computed tomography (CT) findings of these SPNs were analyzed in these three groups to identify the malignant and benign SPNs. The risk factors were analyzed using binary logistic regression analysis.
Of these 379 patients, 120 had benign SPNs and 259 had malignant SPNs. In the ≤10 mm SPN group, air cavity density was the risk factor for malignancy, with the sensitivity, specificity, and accuracy being 77.8%, 75.0%, and 76.3%. In the 11-20 mm SPN group, age, glitches and vascular aggregation were the risk factors for malignancy, with the sensitivity, specificity, and accuracy being 91.3%, 56.9%, and 81.5%. In the >20 mm SPN group, age, lobulation, and vascular aggregation were the risk factors for malignancy, with the sensitivity, specificity, and accuracy being 88.6%, 57.1%, and 79.1%.
According to CT findings of SPNs, age, glitches, lobulation, vascular aggregation, and air cavity density are the risk factors of malignancy, whereas calcification and satellite lesions are the protective factors. During the course of development from small to large nodules, air cavity density could be firstly detected in early stages, followed by glitches and vascular aggregation. Lobulation is associated with relatively large lesions.
PMCID: PMC4073405  PMID: 24976989
Solitary pulmonary nodules (SPNs); computed tomography (CT); logistic regression; risk factors
8.  Clinical outcome of ultrasound-guided percutaneous microwave ablation on colorectal liver metastases 
Oncology Letters  2014;8(1):323-326.
The present study aimed to assess the feasibility, safety and efficiency of ultrasound-guided percutaneous microwave ablation (MWA) on liver metastases from colon or rectal cancer. Patients who received MWA therapy for liver metastases from colon or rectal cancer between June 2009 and May 2012 were enrolled in the study. Follow-up data was collected from the patients in order to statistically analyze the adverse effects, concurrent disease and survival status. Of the total 115 patients, 62 presented with colon cancer and 53 with rectal cancer. A total of 78 patients were male and 37 were female. The patient age ranged between 30 and 86 years [mean ± standard deviation (SD), 59.46±11.79 years]. The number of overall ablation lesions was 165, and the diameter of the lesions ranged between 1.3 and 5.0 cm (mean ± SD, 3.10±1.05 cm). Subsequent to treatment, the mean (± SD) hospitalization time was 4.69±2.08 days (range, 2–10 days). The median follow-up time was 28 months (range, 12–48 months) and 5 patients were lost to follow-up. The pain grade was recorded between the 4th and 6th degree following treatment in 23 patients. The body temperatures of 35 patients reached >38°C, with the longest time at this temperature recorded as 5 days. Following treatment, 5 patients presented with pleural effusion and required thoracocentesis and drainage. Following ablation, the rate of local progression was 11.82%. The recurrence rates were 27.8, 48.4 and 59.3% and the cumulative survival rates were 98.1, 87.1 and 78.7% in years 1, 2 and 3 post-treatment, respectively. A total of 14 patients succumbed. No significant differences were observed in the liver metastases of colorectal cancer with regard to gender, age, number of lesions, lesion size and pathological differentiation (P>0.05). Also, no significant difference was observed in the recurrence or cumulative survival rates for years 1, 2 and 3 years post-treatment (P>0.05). In conclusion, ultrasound-guided percutaneous MWA is a safe and competent way to treat inoperable colorectal liver metastases.
PMCID: PMC4063642  PMID: 24959270
microwave ablation; ultrasound-guided; liver metastases; colorectal cancer
9.  Drug Screening Using a Library of Human Induced Pluripotent Stem Cell-Derived Cardiomyocytes Reveals Disease Specific Patterns of Cardiotoxicity 
Circulation  2013;127(16):10.1161/CIRCULATIONAHA.113.001883.
Cardiotoxicity is a leading cause for drug attrition during pharmaceutical development and has resulted in numerous preventable patient deaths. Incidents of adverse cardiac drug reactions are more common in patients with pre-existing heart disease than the general population. Here we generated a library of human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) from patients with various hereditary cardiac disorders to model differences in cardiac drug toxicity susceptibility for patients of different genetic backgrounds.
Methods and Results
Action potential duration (APD) and drug-induced arrhythmia were measured at the single cell level in hiPSC-CMs derived from healthy subjects and patients with hereditary long QT syndrome (LQT), familial hypertrophic cardiomyopathy (HCM), and familial dilated cardiomyopathy (DCM). Disease phenotypes were verified in LQT, HCM, and DCM iPSC-CMs by immunostaining and single cell patch clamp. Human embryonic stem cell-derived cardiomyocytes (hESC-CMs) and the human ether-a-go-go-related gene (hERG) expressing human embryonic kidney (HEK293) cells were used as controls. Single cell PCR confirmed expression of all cardiac ion channels in patient-specific hiPSC-CMs as well as hESC-CMs, but not in HEK293 cells. Disease-specific hiPSC-CMs demonstrated increased susceptibility to known cardiotoxic drugs as measured by APD and quantification of drug-induced arrhythmias such as early after depolarizations (EADs) and delayed after depolarizations (DADs).
We have recapitulated drug-induced cardiotoxicity profiles for healthy subjects, LQT, HCM, and DCM patients at the single cell level for the first time. Our data indicate that healthy and diseased individuals exhibit different susceptibilities to cardiotoxic drugs and that use of disease-specific hiPSC-CMs may predict adverse drug responses more accurately than standard hERG test or healthy control hiPSC-CM/hESC-CM screening assays.
PMCID: PMC3870148  PMID: 23519760
Induced pluripotent stem cells; stem cells; cardiotoxicity; arrhythmia
10.  Mechanistic Relationships between Drosophila Fragile X Mental Retardation Protein and Metabotropic Glutamate Receptor A Signaling 
Fragile X Syndrome is caused by loss of the FMRP translational regulator. A current hypothesis proposes that FMRP functions downstream of mGluR signaling to regulate synaptic connections. Using the Drosophila disease model, we test relationships between dFMRP and the sole Drosophila mGluR (DmGluRA) by assaying protein expression, behavior and neuron structure in brain and NMJ; in single mutants, double mutants and with an mGluR antagonist. At the protein level, dFMRP is upregulated in dmGluRA mutants, and DmGluRA is upregulated in dfmr1 mutants, demonstrating mutual negative feedback. Null dmGluRA mutants display defects in coordinated movement behavior, which are rescued by removing dFMRP expression. Null dfmr1 mutants display increased NMJ presynaptic structural complexity and elevated presynaptic vesicle pools, which are rescued by blocking mGluR signaling. Null dfmr1 brain neurons similarly display increased presynaptic architectural complexity, which is rescued by blocking mGluR signaling. These data show that DmGluRA and dFMRP convergently regulate presynaptic properties.
PMCID: PMC3989938  PMID: 18280750
Fragile X Syndrome; mental retardation; brain; translation regulator; glutamatergic signaling; axon; synapse; synaptic vesicle
11.  Experimental study of image-guided percutaneous microwave ablation in rabbit lung VX2 tumor model 
Purpose: To investigate the efficacy and safety of percutaneous microwave ablation. Methods: Twenty-six rabbits with lung VX2 tumor were randomly divided into experimental and control group. In the experimental group, microwave ablation guided by ultrasound or CT was performed based on location of the tumor. Enhanced CT scan was carried out immediately before and after the ablation for all animals. Two animals from each group were sacrificed immediately or 1 week after the ablation respectively and the others were followed for the rest of their lives. Results: CT scan revealed that the tumor was greatly reduced or ablated after ablation. Pathological examination immediately after ablation also confirmed the tumor reduction or ablation. The survival time of the animals in the experimental group was significantly longer than that in the control group. Conclusions: Microwave ablation is a safe and effective method for treating lung cancer in rabbits, showing potential clinical applicability.
PMCID: PMC3971292  PMID: 24696709
Microwave ablation; VX2 tumor; lung cancer
12.  Characterization of primary hepatic carcinosarcoma by contrast-enhanced ultrasonography: A case report 
Primary hepatic carcinosarcoma is a rare tumor and is comprised of a mixture of carcinomatous and sarcomatous elements. We present a case of primary carcinosarcoma of the liver in a 59-year-old woman, which was confirmed by pathology following surgical resection. Using contrast-enhanced ultrasonography, the tumor showed peripheral nodular hyperenhancement in the arterial phase with two feeding arterial vessels and a large internal non-enhancing portion in the center. The peripheral nodular portion of the tumor showed hypoenhancement in the later phase.
PMCID: PMC3925875  PMID: 24587642
Liver; Carcinosarcoma; Ultrasonography; Contrast-agent
13.  Abnormal Calcium Handling Properties Underlie Familial Hypertrophic Cardiomyopathy Pathology in Patient-Specific Induced Pluripotent Stem Cells 
Cell stem cell  2013;12(1):101-113.
Familial hypertrophic cardiomyopathy (HCM) is a prevalent hereditary cardiac disorder linked to arrhythmia and sudden cardiac death. While the causes of HCM have been identified as genetic mutations in the cardiac sarcomere, the pathways by which sarcomeric mutations engender myocyte hypertrophy and electrophysiological abnormalities are not understood. To elucidate the mechanisms underlying HCM development, we generated patient-specific induced pluripotent stem cell cardiomyocytes (iPSC-CMs) from a ten-member family cohort carrying a hereditary HCM missense mutation (Arg663His) in the MYH7 gene. Diseased iPSC-CMs recapitulated numerous aspects of the HCM phenotype including cellular enlargement and contractile arrhythmia at the single-cell level. Calcium (Ca2+) imaging indicated dysregulation of Ca2+ cycling and elevation in intracellular Ca2+ ([Ca2+]i) are central mechanisms for disease pathogenesis. Pharmacological restoration of Ca2+ homeostasis prevented development of hypertrophy and electrophysiological irregularities. We anticipate that these findings will help elucidate the mechanisms underlying HCM development and identify novel therapies for the disease.
PMCID: PMC3638033  PMID: 23290139
14.  Predicting Early Intrahepatic Recurrence of Hepatocellular Carcinoma after Microwave Ablation Using SELDI-TOF Proteomic Signature 
PLoS ONE  2013;8(12):e82448.
Despite great progress in the treatment of hepatocellular carcinoma (HCC) over the last-decade, intrahepatic recurrence is still the most frequent serious adverse event after all the treatments including microwave ablation. This study aimed to predict early recurrence of HCC after microwave ablation using serum proteomic signature.
After curative microwave ablation of HCC, 86 patients were followed-up for 1 year. Serum samples were collected before microwave ablation. The mass spectra of proteins were generated using surface-enhanced laser desorption/ionization time-of-flight mass spectrometry (SELDI-TOF MS). Serum samples from 50 patients were randomly selected as a training set and for biomarkers discovery and model development. The remaining serum samples were categorized for validation of the algorithm.
According to preablation serum protein profiling obtained from the 50 HCC samples in the training set, nine significant differentially-expressed proteins were detected in the serum samples between recurrent and non-recurrent patients. Decision classification tree combined with three candidate proteins with m/z values of 7787, 6858 and 6646 was produced using Biomarker Patterns Software with sensitivity of 85.7% and specificity of 88.9% in the training set. When the SELDI marker pattern was tested with the blinded testing set, it yielded a sensitivity of 80.0%, a specificity of 88.5% and a positive predictive value of 86.1%.
Differentially-expressed protein peaks in preablation serum screened by SELDI are associated with prognosis of HCC. The decision classification tree is a potential tool in predicting early intrahepatic recurrence in HCC patients after microwave ablation.
PMCID: PMC3862627  PMID: 24349287
15.  Genome Editing of Human Embryonic Stem Cells and Induced Pluripotent Stem Cells With Zinc Finger Nuclease for Cellular Imaging 
Circulation research  2012;111(12):1494-1503.
Molecular imaging has proven to be a vital tool in the characterization of stem cell behavior in vivo. However, the integration of reporter genes has typically relied upon random integration, a method that is associated with unwanted insertional mutagenesis and position effects on transgene expression.
To address this barrier, we used genome editing with zinc finger nuclease technology to integrate reporter genes into a safe harbor gene locus (PPP1R12C, also known as AAVS1) in the genome of human embryonic stem cells (hESCs) and human induced pluripotent stem cells (iPSCs) for molecular imaging.
Methods and Results
We employed ZFN technology to integrate a construct containing monomeric red fluorescent protein (mRFP), firefly luciferase (Fluc), and herpes simplex virus thymidine kinase (HSVtk) reporter genes driven by a constitutive ubiquitin promoter into a safe harbor locus for bioluminescence imaging (BLI) and positron emission tomography (PET) imaging, respectively. High efficiency of ZFN-mediated targeted integration was achieved in both hESCs and iPSCs. ZFN-edited cells maintained both pluripotency and long-term reporter gene expression. Functionally, we successfully tracked the survival of ZFN-edited hESCs, iPSCs, and their differentiated cardiomyocytes and endothelial cells in murine models, demonstrating the utility of ZFN-edited cells for preclinical studies in regenerative medicine.
Our study demonstrates a novel application of ZFN technology to the targeted genetic engineering of human pluripotent stem cells (PSCs) and their progeny for molecular imaging in vitro and in vivo.
PMCID: PMC3518748  PMID: 22967807
Induced pluripotent stem cells; zinc finger nuclease; homologous recombination; reporter gene; molecular imaging; stem cells; imaging
16.  Integration of the Image-Guided Surgery Toolkit (IGSTK) into the Medical Imaging Interaction Toolkit (MITK) 
Journal of Digital Imaging  2012;25(6):729-737.
The development cycle of an image-guided surgery navigation system is too long to meet current clinical needs. This paper presents an integrated system developed by the integration of two open-source software (IGSTK and MITK) to shorten the development cycle of the image-guided surgery navigation system and save human resources simultaneously. An image-guided surgery navigation system was established by connecting the two aforementioned open-source software libraries. It used the Medical Imaging Interaction Toolkit (MITK) as a framework providing image processing tools for the image-guided surgery navigation system of medical imaging software with a high degree of interaction and used the Image-Guided Surgery Toolkit (IGSTK) as a library that provided the basic components of the system for location, tracking, and registration. The electromagnetic tracking device was used to measure the real-time position of surgical tools and fiducials attached to the patient’s anatomy. IGSTK was integrated into MITK; at the same time, the compatibility and the stability of this system were emphasized. Experiments showed that an integrated system of the image-guided surgery navigation system could be developed in 2 months. The integration of IGSTK into MITK is feasible. Several techniques for 3D reconstruction, geometric analysis, mesh generation, and surface data analysis for medical image analysis of MITK can connect with the techniques for location, tracking, and registration of IGSTK. This integration of advanced modalities can decrease software development time and emphasize the precision, safety, and robustness of the image-guided surgery navigation system.
PMCID: PMC3491160  PMID: 22535192
MITK; IGSTK; Image-guided surgery navigation; Development cycle; Open-source software; Integration
17.  Role of contrast-enhanced ultrasound in evaluating the efficiency of ultrasound guided percutaneous microwave ablation in patients with renal cell carcinoma 
Radiology and Oncology  2013;47(4):398-404.
The aim of the study was to evaluate the efficiency and feasibility of contrast-enhanced ultrasound (CEUS) with Sonovue in assessing of renal cell carcinomas (RCCs) following ultrasound (US)-guided percutaneous microwave ablation (MWA).
Patinets and methods
Seventy-nine patients (60 males and 19 females) with 83 lesions (mean size 3.2±1.6 cm) were treated by US-guided percutaneous MWA. The CEUS results of the third day after the ablation were compared with the synchronous contrast-enhanced computed tomography (CT)/magnetic resonance imaging (MRI) results and biopsy pathological results. The follow-up was performed by CEUS and CT/MRI after 1, 3, 6 months and every 6 months subsequently. The combination of clinical follow-up results and CT/MRI imaging findings was the reference standard of CEUS results for evaluating the therapeutic effect. The identification of residual or recurrence tumour was assessed by two blinded radiologists.
On the third day after MWA, CEUS showed 68 of 83 lesions (68/83, 81.9%) successfully ablated and 15 of 83 (18.1%) with residual tumours. Among residual tumours, 13 (86.7%) were confirmed by contrast-enhanced CT/MRI findings and biopsy results. The sensitivity, specificity, accuracy, positive and negative predictive value of CEUS evaluating the short-term MWA effectiveness were 100%, 97.1%, 97.6%, 86.7% and 100%, respectively. During the six years follow-up (median 26 months), the CEUS showed recurrence in 7 patients, and six of them achieved consistent results on CEUS and CT/MRI imaging. The sensitivity, specificity, accuracy, positive and negative predictive value for CEUS evaluating long-term MWA effectiveness were 85.7%, 98.7%, 97.6%, 85.7% and 98.7%, respectively.
The post-procedural CEUS demonstrated as an effective and feasible method in evaluating a therapeutic effect of RCCs following MWA.
PMCID: PMC3814286  PMID: 24294186
contras enhanced ultrasound; microwave ablation; renal cell carcinoma
18.  Study of Modern Human Evolution via Comparative Analysis with the Neanderthal Genome 
Genomics & Informatics  2013;11(4):230-238.
Many other human species appeared in evolution in the last 6 million years that have not been able to survive to modern times and are broadly known as archaic humans, as opposed to the extant modern humans. It has always been considered fascinating to compare the modern human genome with that of archaic humans to identify modern human-specific sequence variants and figure out those that made modern humans different from their predecessors or cousin species. Neanderthals are the latest humans to become extinct, and many factors made them the best representatives of archaic humans. Even though a number of comparisons have been made sporadically between Neanderthals and modern humans, mostly following a candidate gene approach, the major breakthrough took place with the sequencing of the Neanderthal genome. The initial genome-wide comparison, based on the first draft of the Neanderthal genome, has generated some interesting inferences regarding variations in functional elements that are not shared by the two species and the debated admixture question. However, there are certain other genetic elements that were not included or included at a smaller scale in those studies, and they should be compared comprehensively to better understand the molecular make-up of modern humans and their phenotypic characteristics. Besides briefly discussing the important outcomes of the comparative analyses made so far between modern humans and Neanderthals, we propose that future comparative studies may include retrotransposons, pseudogenes, and conserved non-coding regions, all of which might have played significant roles during the evolution of modern humans.
PMCID: PMC3897851  PMID: 24465235
biological evolution; comparative genomics; humans; Neanderthals
19.  Identification of three new Alu Yb subfamilies by source tracking of recently integrated Alu Yb elements 
Mobile DNA  2013;4:25.
Alu elements are the most abundant mobile elements in the human genome, with over 1 million copies and constituting more than 10% of the genome. The majority of these Alu elements were inserted into the primate genome 35 to 60 million years ago, but certain subfamilies of Alu elements are relatively very new and suspected to be still evolving. We attempted to trace the source/master copies of all human-specific members of the Alu Yb lineage using a computational approach by clustering similar Yb elements and constructing an evolutionary relation among the members of a cluster.
We discovered that one copy of Yb8 at 10p14 is the source of several active Yb8 copies, which retrotransposed to generate 712 copies or 54% of all human-specific Yb8 elements. We detected eight other Yb8 elements that had generated ten or more copies, potentially acting as 'stealth drivers’. One Yb8 element at 14q32.31 seemed to act as the source copy for all Yb9 elements tested, having producing 13 active Yb9 elements, and subsequently generated a total of 131 full-length copies. We identified and characterized three new subclasses of Yb elements: Yb8a1, Yb10 and Yb11. Their copy numbers in the reference genome are 75, 8 and 16. We analysed personal genome data from the 1000 Genome Project and detected an additional 6 Yb8a1, 3 Yb10 and 15 Yb11 copies outside the reference genome. Our analysis indicates that the Yb8a1 subfamily has a similar age to Yb9 (1.93 million years and 2.15 million years, respectively), while Yb10 and Yb11 evolved only 1.4 and 0.71 million years ago, suggesting a linear evolutionary path from Yb8a1 to Yb10 and then to Yb11. Our preliminary data indicate that members in Yb10 and Yb11 are mostly polymorphic, indicating their young age.
Our findings suggest that the Yb lineage is still evolving with new subfamilies being formed. Due to their very young age and the high rate of being polymorphic, insertions from these young subfamilies are very useful genetic markers for studying human population genetics and migration patterns, and the trend for mobile element insertions in the human genome.
PMCID: PMC3831846  PMID: 24216009
Mobile element; Alu; evolution; Alu Yb8a1; Alu Yb10; Alu Yb11
20.  Magneto-electric Nanoparticles to Enable Field-controlled High-Specificity Drug Delivery to Eradicate Ovarian Cancer Cells 
Scientific Reports  2013;3:2953.
The nanotechnology capable of high-specificity targeted delivery of anti-neoplastic drugs would be a significant breakthrough in Cancer in general and Ovarian Cancer in particular. We addressed this challenge through a new physical concept that exploited (i) the difference in the membrane electric properties between the tumor and healthy cells and (ii) the capability of magneto-electric nanoparticles (MENs) to serve as nanosized converters of remote magnetic field energy into the MENs' intrinsic electric field energy. This capability allows to remotely control the membrane electric fields and consequently trigger high-specificity drug uptake through creation of localized nano-electroporation sites. In in-vitro studies on human ovarian carcinoma cell (SKOV-3) and healthy cell (HOMEC) lines, we applied a 30-Oe d.c. field to trigger high-specificity uptake of paclitaxel loaded on 30-nm CoFe2O4@BaTiO3 MENs. The drug penetrated through the membrane and completely eradicated the tumor within 24 hours without affecting the normal cells.
PMCID: PMC3797424  PMID: 24129652
21.  Induced Pluripotent Stem Cells as a Disease Modeling and Drug Screening Platform 
Induced pluripotent stem cells (iPSCs) hold great hopes for therapeutic application in various diseases. While ongoing research is dedicated to achieving clinical translation of iPSCs, further understanding of the mechanisms that underlie complex pathogenic conditions is required. Compared to other classical models for studying diseases, iPSCs provide considerable advantages. A newly emerging application of iPSCs is in vitro disease modeling, which can significantly improve the never-ending search for new pharmacological cures. Here, we will discuss current efforts to create iPSC-dependent, patient-specific disease models. Furthermore, we will review the use of iPSCs for development and testing of new therapeutic agents, and the implications for high-throughput drug screening.
PMCID: PMC3343213  PMID: 22240913
Induced pluripotent stem cells; Disease modeling; Cardiovascular disease; Drug screening; High-throughput screening
22.  Practice guidelines for ultrasound-guided percutaneous microwave ablation for hepatic malignancy 
Primary liver cancer and liver metastases are among the most frequent malignancies worldwide, with an increasing number of new cases and deaths every year. Traditional surgery is only suitable for a limited proportion of patients and imaging-guided percutaneous thermal ablation has achieved optimistic results for management of hepatic malignancy. This synopsis outlines the first clinical practice guidelines for ultrasound-guided percutaneous microwave ablation therapy for hepatic malignancy, which was created by a joint task force of the Society of Chinese Interventional Ultrasound. The guidelines aim at standardizing the microwave ablation procedure and therapeutic efficacy assessment, as well as proposing the criteria for the treatment candidates.
PMCID: PMC3761095  PMID: 24023485
Practice guidelines; Microwave radiation; Catheter ablation; Liver cancer; Ultrasound
23.  Differentiation of Central Lung Cancer from Atelectasis: Comparison of Diffusion-Weighted MRI with PET/CT 
PLoS ONE  2013;8(4):e60279.
Prospectively assess the performance of diffusion-weighted magnetic resonance imaging (DW-MRI) for differentiation of central lung cancer from atelectasis.
Materials and Methods
38 consecutive lung cancer patients (26 males, 12 females; age range: 28–71 years; mean age: 49 years) who were referred for thoracic MR imaging examinations were enrolled. MR examinations were performed using a 1.5-T clinical scanner and scanning sequences of T1WI, T2WI, and DWI. Cancers and atelectasis were measured by mapping of the apparent diffusion coefficients (ADCs) obtained with a b-value of 500 s/mm2.
PET/CT and DW-MR allowed differentiation of tumor and atelectasis in all 38 cases, but T2WI did not allow differentiation in 9 cases. Comparison of conventional T2WI and DW-MRI indicated a higher contrast noise ratio of the central lung carcinoma than the atelectasis by DW-MRI. ADC maps indicated significantly lower mean ADC in the central lung carcinoma than in the atelectasis (1.83±0.58 vs. 2.90±0.26 mm2/s, p<0.0001). ADC values of small cell lung carcinoma were significantly greater than those from squamous cell carcinoma and adenocarcinoma (p<0.0001 for both).
DW-MR imaging provides valuable information not obtained by conventional MR and may be useful for differentiation of central lung carcinoma from atelectasis. Future developments may allow DW-MR imaging to be used as an alternative to PET-CT in imaging of patients with lung cancer.
PMCID: PMC3617228  PMID: 23593186
24.  microRNA response elements-regulated TRAIL expression shows specific survival-suppressing activity on bladder cancer 
Bladder transitional cell carcinoma greatly threatens human health all over the world. Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) shows a strong apoptosis-inducing effect on a variety of cancer cells including bladder cancer. However, adenovirus-mediated TRAIL expression still showed cytotoxicity to normal cells mainly due to lack of tumor specificity.
To solve the problem, we applied miRNA response elements (MREs) of miR-1, miR-133 and miR-218 to confer TRAIL expression with specificity to bladder cancer cells.
Expression of miR-1, miR-133 and miR-218 was greatly decreased in bladder cancer than normal bladder tissue. Luciferase assay showed that application of the 3 MREs was able to restrain exogenous gene expression to within bladder cancer cells. Subsequently, we constructed a recombinant adenovirus with TRAIL expression regulated by MREs of miR-1, miR-133 and miR-218, namely Ad-TRAIL-MRE-1-133-218. qPCR, immunoblotting and ELISA assays demonstrated that Ad-TRAIL-MRE-1-133-218 expressed in bladder cancer cells, rather than normal bladder cells. The differential TRAIL expression also led to selective apoptosis-inducing and growth-inhibiting effect of Ad-TRAIL-MRE-1-133-218 on bladder cancers. Finally, bladder cancer xenograft in mouse models further confirmed that Ad-TRAIL-MRE-1-133-218 effectively suppressed the growth of bladder cancers.
Collectively, we demonstrated that MREs-based TRAIL delivery into bladder cancer cells was feasible and efficient for cancer gene therapy.
PMCID: PMC3764979  PMID: 23442927
Bladder cancer; Adenovirus; miRNA; Specificity; TRAIL
25.  Genetic analysis of Down syndrome facilitated by mouse chromosome engineering 
Bioengineered Bugs  2012;3(1):8-12.
Human trisomy 21 is the most frequent live-born human aneuploidy and causes a constellation of disease phenotypes classified as Down syndrome, which include heart defects, myeloproliferative disorder, cognitive disabilities and Alzheimer-type neurodegeneration. Because these phenotypes are associated with an extra copy of a human chromosome, the genetic analysis of Down syndrome has been a major challenge. To complement human genetic approaches, mouse models have been generated and analyzed based on evolutionary conservation between the human and mouse genomes. These efforts have been greatly facilitated by Cre/loxP-mediated mouse chromosome engineering, which may result in the establishment of minimal critical genomic regions and eventually new dosage-sensitive genes associated with Down syndrome phenotypes. The success in genetic analysis of Down syndrome will further enhance our understanding of this disorder and lead to better strategies in developing effective therapeutic interventions.
PMCID: PMC3329253  PMID: 22126738
chromosome engineering; Down syndrome; genetic dissection; mouse models; trisomy 21

Results 1-25 (68)