Search tips
Search criteria

Results 1-25 (104)

Clipboard (0)

Select a Filter Below

more »
Year of Publication
more »
1.  Evaluation of Non-Local Means Based Denoising Filters for Diffusion Kurtosis Imaging Using a New Phantom 
PLoS ONE  2015;10(2):e0116986.
Image denoising has a profound impact on the precision of estimated parameters in diffusion kurtosis imaging (DKI). This work first proposes an approach to constructing a DKI phantom that can be used to evaluate the performance of denoising algorithms in regard to their abilities of improving the reliability of DKI parameter estimation. The phantom was constructed from a real DKI dataset of a human brain, and the pipeline used to construct the phantom consists of diffusion-weighted (DW) image filtering, diffusion and kurtosis tensor regularization, and DW image reconstruction. The phantom preserves the image structure while minimizing image noise, and thus can be used as ground truth in the evaluation. Second, we used the phantom to evaluate three representative algorithms of non-local means (NLM). Results showed that one scheme of vector-based NLM, which uses DWI data with redundant information acquired at different b-values, produced the most reliable estimation of DKI parameters in terms of Mean Square Error (MSE), Bias and standard deviation (Std). The result of the comparison based on the phantom was consistent with those based on real datasets.
PMCID: PMC4313935  PMID: 25643162
2.  Development and In Vivo Evaluation of Small-Diameter Vascular Grafts Engineered by Outgrowth Endothelial Cells and Electrospun Chitosan/Poly(ɛ-Caprolactone) Nanofibrous Scaffolds 
Tissue Engineering. Part A  2013;20(1-2):79-91.
Successful engineering of a small-diameter vascular graft is still a challenge despite numerous attempts for decades. The present study aimed at developing a tissue-engineered vascular graft (TEVG) using autologous outgrowth endothelial cells (OECs) and a hybrid biodegradable polymer scaffold. OECs were harvested from canine peripheral blood and proliferated in vitro, as well as identified by immunofluorescent staining. Electrospun hybrid chitosan/poly(ɛ-caprolactone) (CS/PCL) nanofibers were fabricated and served as vascular scaffolds. TEVGs were constructed in vitro by seeding OECs onto CS/PCL scaffolds, and then implanted into carotid arteries of cell-donor dogs (n=6). After 3 months of implantation, 5 out of 6 of TEVGs remained patent as compared with 1 out of 6 of unseeded grafts kept patent. Histological and immunohistochemical analyses of the TEVGs retrieved at 3 months revealed the regeneration of endothelium, and the presence of collagen and elastin. OECs labeled with fluorescent dye before implantation were detected in the retrieved TEVGs, indicating that the OECs participated in the vascular tissue regeneration. Biomechanical testing of TEVGs showed good mechanical properties that were closer to native carotid arteries. RT-PCR and western blot analysis demonstrated that TEVGs had favorable biological functional properties resembling native arteries. Overall, this study provided a new strategy to develop small-diameter TEVGs with excellent biocompatibility and regeneration ability.
PMCID: PMC3875210  PMID: 23902162
3.  In vitro and in vivo mapping of drug release after laser ablation thermal therapy with doxorubicin-loaded hollow gold nanoshells using fluorescence and photoacoustic imaging 
Doxorubicin-loaded hollow nanoshells (Dox@PEG-HAuNS) increases the efficacy of photothermal ablation (PTA) by not only mediating efficient PTA but also through chemotherapy, and therefore have potential utility for local anticancer therapy. However, in vivo real-time monitoring of Dox release and temperature achieved during the laser ablation technique has not been previously demonstrated before. In this study, we used fluorescence optical imaging to map the release of Dox from Dox@PEG-HAuNS and photoacoustic imaging to monitor the tumor temperature achieved during near-infrared laser–induced photothermal heating in vitro and in vivo. In vitro, treatment with a 3-W laser was sufficient to initiate the release of Dox from Dox@PEG-HAuNS (1:3:1 wt/wt, 1.32×1012 particles/mL). Laser powers of 3 and 6 W achieved ablative temperatures of more than 50 °C. In 4T1 tumor–bearing nude mice that received intratumoral or intravenous injections of Dox@PEG-HAuNS, fluorescence optical imaging (emission wavelength = 600 nm, excitation wavelength = 500 nm) revealed that the fluorescence intensity in surface laser–treated tumors 24 h after treatment was significantly higher than that in untreated tumors (p=0.015 for intratumoral, p=0.008 for intravenous). Similar results were obtained using an interstitial laser to irradiate tumors following the intravenous injection of Dox@PEG-HAuNS (p=0.002 at t=24h). Photoacoustic imaging (acquisition wavelength = 800 nm) revealed that laser treatment caused a substantial increase in tumor temperature, from 37 °C to ablative temperatures of more than 50 °C. Ex vivo analysis revealed that the fluorescence intensity of laser-treated tumors was twice as high as that of untreated tumors (p=0.009). Histological analysis confirmed that intratumoral injection of Dox@PEG-HAuNS and laser treatment caused significantly more tumor necrosis compared to tumors that were not treated with laser (p<0.001). On the basis of these findings, we conclude that fluorescence optical imaging and photoacoustic imaging are promising approaches to assessing Dox release and monitoring temperature, respectively, after Dox@PEG-HAuNS–mediated thermal ablation therapy.
PMCID: PMC3853126  PMID: 23920038
targeted hollow gold nanoshells; magnetic resonance temperature imaging; photoacoustic imaging; near-infrared optical imaging; molecular imaging
4.  Transcriptional silencing of ETS-1 abrogates epithelial-mesenchymal transition resulting in reduced motility of pancreatic cancer cells 
Oncology Reports  2014;33(2):559-565.
v-ets erythroblastosis virus E26 oncogene homolog 1 (ETS-1) plays crucial roles in a spectrum of malignancies. ETS-1 has gained attention in cancer research for its importance in cell migration, invasion and proliferation. In the present study, we focused on the effect of ETS-1 on epithelial-mesenchymal transition (EMT), which is characterized by reduced E-cadherin expression and increased N-cadherin expression. We found that ETS-1 mRNA expression was positively correlated with N-cadherin and negatively correlated with E-cadherin mRNA expression in five pancreatic cancer cell lines. To elucidate the functionality of ETS-1 on EMT in pancreatic cancer cells, we constructed a green fluorescent protein (GFP)-expressing plasmid carrying ETS-1 short hairpin RNA (shRNA), and transfected Panc-1 cells with the plasmid. We detected reduced N-cadherin and vascular endothelial growth factor yet higher E-cadherin expression in the ETS-1-silenced cells compared with the control group. In addition, we observed reduced cell migration and increased adhesion in these cells. Our data showed that ETS-1 actively functioned as a regulator of EMT in Panc-1 cells, and provide additional evidence supporting a fundamental role for ETS-1 in metastatic pancreatic cancer cells. These results suggest that analysis of ETS-1 expression levels may provide an avenue for evaluating prognosis in pancreatic cancer.
PMCID: PMC4306275  PMID: 25421630
ETS-1; cell motility; epithelial-mesenchymal transition; pancreatic cancer cells
5.  Role of PET/CT in the diagnosis, staging, and follow-up of a nasal-type natural killer T-cell lymphoma in the larynx: a case report and literature review 
Background: Nasal-type natural killer T-cell lymphoma involving the larynx is uncommon. Our search revealed only 12 cases reported previously in the English-language literature. Case report: We report a case of laryngeal NKTCL. In December 2011, the patient was diagnosed with nasal-type NKTCL and FDG PET/CT showed the lesions were confined to the nasal cavity (stage I). At 1 year after radiotherapy, the patient presented with hoarseness and FDG PET/CT revealed high FDG uptake in the subglottic region and left cervical lymph nodes. A biopsy of the subglottis confirmed NKTCL (stage II). He then received chemotherapy and 14 months after the completion of chemotherapy, FDG PET/CT showed no evidence of recurrence or metastasis. Conclusions: PET/CT has better sensitivity than other conventional methods and may play an important role in the diagnosis, staging, and follow-up of nasal-type natural killer T-cell lymphoma.
PMCID: PMC4276232  PMID: 25550974
Natural killer T-cell lymphoma; larynx; PET/CT; follow-up
6.  A comparison of posterior lumbar interbody fusion and transforaminal lumbar interbody fusion: a literature review and meta-analysis 
We compared the perioperative results and complications associated with PLIF and TLIF, and collected evidence for choosing the better fusion method.
A literature survey of the MEDLINE and EMBASE databases identified 7 comparative observational studies that met our inclusion criteria. Checklists by Cowley were used to evaluate the risk of bias of the included studies. A database including patient demographic information, perioperative results, and complications was established. The summary odds ratio and weighed mean difference with 95% confidence interval were calculated with a random-effects model.
We found that PLIF had a higher complication rate (P <0.00001), and TLIF reduced the rate of durotomy (P = 0.01). No statistical difference was found between the two groups with regard to clinical satisfaction (P = 0.54), blood loss (P = 0.14), vertebral root injury (P = 0.08), graft malposition (P = 0.06), infection (P = 0.36), or rate of radiographic fusion (P = 0.27). The evidence indicated that PLIF required longer operative time (P = 0.03).
The evidence indicated that TLIF could reduce the complication rate and durotomy. Neither TLIP nor PLIF was found superior in terms of clinical satisfaction or radiographic fusion rate. PLIF might result in longer time in surgery.
PMCID: PMC4232693  PMID: 25373605
Posterior lumbar interbody fusion; Transforaminal lumbar interbody fusion; Meta-analysis; Lumbar fusion
7.  Study on the Promotion of Bacterial Biofilm Formation by a Salmonella Conjugative Plasmid and the Underlying Mechanism 
PLoS ONE  2014;9(10):e109808.
To investigate the effect of the pRST98 plasmid, originally isolated from Salmonella enterica serovar Typhi (S. Typhi), on biofilm (BF) formation, we carried out in vitro experiments using S. Typhi, Salmonella enterica serovar Typhimurium (S. Typhimurium) and Escherichia coli (E. coli). We further explored the effects of pRST98 in vivo by establishing two animal models, a tumor-bearing mouse model and a mouse urethral catheter model. Moreover, we examined the relationship between the quorum-sensing (QS) system and pRST98-mediated BF formation. These studies showed that pRST98 enhanced BF formation in different bacteria in vitro. In both animal models, pRST98 promoted BF formation and caused more severe pathological changes. It was previously reported that Salmonella senses exogenous N-acylhomoserine lactones (AHLs) through the regulatory protein SdiA and regulates the expression of genes including the virulence gene rck, which is located on the virulence plasmid of some serotypes of Salmonella. In this study, we confirmed the locus of the rck gene on pRST98 and found that AHLs increased rck expression in pRST98-carrying strains, thereby enhancing bacterial adherence, serum resistance and bacterial BF formation. In conclusion, the Salmonella conjugative plasmid pRST98 promotes bacterial BF formation both in vitro and in vivo, and the mechanism may relate to the AHL-SdiA-Rck signaling pathway.
PMCID: PMC4192535  PMID: 25299072
8.  Ectopic Osteogenesis of Macroscopic Tissue Constructs Assembled from Human Mesenchymal Stem Cell-Laden Microcarriers through In Vitro Perfusion Culture 
PLoS ONE  2014;9(10):e109214.
We had previously demonstrated the feasibility of preparing a centimeter-sized bone tissue construct by following a modular approach. In the present study, the objectives were to evaluate osteogenesis and tissue formation of human amniotic mesenchymal stem cells-laden CultiSpher S microcarriers during in vitro perfusion culture and after subcutaneous implantation. Microtissues were prepared in dynamic culture using spinner flasks in 28 days. In comparison with 1-week perfusion culture, microtissues became more obviously fused, demonstrating significantly higher cellularity, metabolic activity, ALP activity and calcium content while maintaining cell viability after 2-week perfusion. After subcutaneous implantation in nude mice for 6 and 12 weeks, all explants showed tight contexture, suggesting profound tissue remodeling in vivo. In addition, 12-week implantation resulted in slightly better tissue properties. However, in vitro perfusion culture time exerted great influence on the properties of corresponding explants. Degradation of microcarriers was more pronounced in the explants of 2-week perfused macrotissues compared to those of 1-week perfusion and directly implanted microtissues. Moreover, more blood vessel infiltration and bone matrix deposition with homogeneous spatial distribution were found in the explants of 2-week perfused macrotissues. Taken together, in vitro perfusion culture time is critical in engineering bone tissue replacements using such a modular approach, which holds great promise for bone regeneration.
PMCID: PMC4183582  PMID: 25275528
9.  Comparison of hybrid procedure and open surgical revascularization for multilevel infrainguinal arterial occlusive disease 
To compare outcomes of hybrid (combined surgical and endovascular) procedures (HYBRID) with open surgical reconstructions (OPEN) in patients with multilevel infrainguinal artery occlusive diseases.
Case series study with retrospective analysis of prospectively collected nonrandomized data.
Between 2008 and 2012, 64 patients underwent OPEN and 43 underwent HYBRID. Patient characteristics, technique success, clinical improvement, and procedure-related morbidity were reviewed and compared. Patency rates and limb salvages were analyzed and compared using Kaplan–Meier life tables. Cox regression analyses were used to assess the influence of various risk factors on primary patency.
HYBRID patients were older and presented with worse New York Heart Association function compared with OPEN patients. The increase in the ankle-brachial index and improvement of Ruthford category after procedures were equivalent between two groups, but HYBRID patients had shorter hospital length of stay (7.6±12.0 versus 15.5±17.3; P= 0.018) and less overall perioperative morbidity (12% versus 28%; P=0.042) compared with OPEN patients. No statistically significant difference in 36-month primary (47.1%±7.1% versus 50.1%±9.4%; P=0.418), assisted primary (57.0%±7.9% versus 62.4%±9.2%; P=0.517), or secondary (82.0%±6.8% versus 83.1%±7.3%; P=0.445) patency was seen between the two groups. Limb salvage rates of HYBRID vs OPEN at 3 years were similar (76.3%±9.3% versus 80.4%±8.2%; P=0.579). Critical limb ischemia was a negative predictor of long-term patency of patients in both the HYBRID and OPEN groups (P=0.012 and P<0.001, respectively), and the presence of diabetes and renal insufficiency were another two independent predictors of decreased primary patency for HYBRID (P=0.017 and P=0.019, respectively).
Multilevel infrainguinal artery occlusive diseases could be treated by hybrid procedure, with shorter hospitalization, less perioperative morbidity, and similar early- and long-term efficacy compared with open revascularization. A hybrid procedure should be considered for patients with high surgical risk, but critical limb ischemia, diabetes, and renal insufficiency could compromise its long-term patency.
PMCID: PMC4181442  PMID: 25284992
hybrid procedure; atherosclerotic occlusive disease; endovascular treatment
10.  Ion Mobility Mass Spectrometry of a Rotary ATPase Reveals ATP-induced Reduction in Conformational Flexibility 
Nature chemistry  2014;6(3):208-215.
Rotary ATPases play fundamental roles in energy conversion, their catalytic rotation being associated with inter-domain fluctuations and heterogeneity of conformational states. Using ion mobility mass spectrometry (IM-MS) we compare the conformational dynamics of the intact ATPase from Thermus thermophilus (TtATPase) with its membrane and soluble subcomplexes. Our results define regions with enhanced flexibility assigned to distinct subunits within the overall assembly. To provide a structural context for our experimental data we performed molecular dynamics (MD) simulations and observed conformational changes of the peripheral stalks reflecting their intrinsic flexibility. By isolating complexes at different phases of cell growth and manipulating nucleotides, metal ions and pH during isolation, we reveal differences that can be related to conformational changes in the Vo complex, triggered by ATP binding. Together these results implicate nucleotides in modulating flexibility of the stator components and uncover mechanistic detail underlying operation and regulation in the context of the holo-enzyme.
PMCID: PMC4067995  PMID: 24557135
11.  Suppressor of Zeste 12 homolog RNA interference inhibits retinoblastoma cell invasion 
Oncology Letters  2014;8(5):1933-1936.
Suppressor of Zeste 12 homolog (SUZ12) is known to regulate tumor phenotype through altering gene expression, with an important regulatory role in tumor genesis and development. SUZ12 has been widely investigated; however, no studies regarding the role of the SUZ12 gene in retinoblastoma (RB) have been conducted. In this study, SUZ12 small interfering (si)RNA was transfected into SO-RB50 human RB cells. The influence of SUZ siRNA on RB cell invasion was detected using a soft agar colony forming assay and a Transwell cabin model. The effect of the SUZ12 siRNA on the expression levels of the associated proteins, vascular endothelial growth factor (VEGF), matrix metalloproteinase (MMP)-9 and MMP-2, was detected by western blotting. The number of cell clones was found to be reduced by the siRNA in a dose-dependent manner, and the number of cells that had permeated through the filter membrane was reduced following transfection with the siRNA. SUZ12 inhibition resulted in a marked reduction in VEGF, MMP-2 and MMP-9 expression levels (0.26±0.04, 0.16±0.02 and 0.12±0.02, respectively) compared with the levels in the non-transfected group (0.80±0.10, 0.94±0.16 and 1.15±0.18, respectively) (P<0.01). In conclusion, SUZ12 siRNA inhibited cell invasion and the expression of VEGF, MMP-2 and MMP-9 in SO-RB50 retinoblastoma cells.
PMCID: PMC4186612  PMID: 25295075
suppressor of Zeste 12 homolog; RNA interference; retinoblastoma; invasion
12.  Categorical Properties of Soft Sets 
The Scientific World Journal  2014;2014:783056.
The present study investigates some novel categorical properties of soft sets. By combining categorical theory with soft set theory, a categorical framework of soft set theory is established. It is proved that the category SFun of soft sets and soft functions has equalizers, finite products, pullbacks, and exponential properties. It is worth mentioning that we find that SFun is both a topological construct and Cartesian closed. The category SRel of soft sets and Z-soft set relations is also characterized, which shows the existence of the zero objects, biproducts, additive identities, injective objects, projective objects, injective hulls, and projective covers. Finally, by constructing proper adjoint situations, some intrinsic connections between SFun and SRel are established.
PMCID: PMC4157215  PMID: 25215333
13.  Protein Production for Structural Genomics Using E. coli Expression 
The goal of structural biology is to reveal details of the molecular structure of proteins in order to understand their function and mechanism. X-ray crystallography and NMR are the two best methods for atomic level structure determination. However, these methods require milligram quantities of proteins. In this chapter a reproducible methodology for large-scale protein production applicable to a diverse set of proteins is described. The approach is based on protein expression in E. coli as a fusion with a cleavable affinity tag that was tested on over 20,000 proteins. Specifically, a protocol for fermentation of large quantities of native proteins in disposable culture vessels is presented. A modified protocol that allows for the production of selenium-labeled proteins in defined media is also offered. Finally, a method for the purification of His6-tagged proteins on immobilized metal affinity chromatography columns that generates high-purity material is described in detail.
PMCID: PMC4108990  PMID: 24590711
Protein expression; Protein purification; Disposable vessel fermentation; Selenomethionine-labeling; IMAC; His-tag; High-throughput
14.  Comparison of Clinical Safety and Outcomes of Early versus Delayed Laparoscopic Cholecystectomy for Acute Cholecystitis: A Meta-Analysis 
The Scientific World Journal  2014;2014:274516.
Objective. To compare the clinical safety and outcomes of early laparoscopic cholecystectomy versus delayed laparoscopic cholecystectomy for acute cholecystitis. Methods. Pertinent studies were selected from the Medline, EMBASE, and Cochrane library databases, references from published articles, and reviews. Seven randomized controlled trials (early laparoscopic cholecystectomy versus delayed laparoscopic cholecystectomy) were selected. Conventional meta-analysis according to Cochrane Collaboration was used for the pooling of the results. Results. Seven trials with 1106 patients were included. There was no significant difference between the two groups in terms of bile duct injury (Peto odds ratio 0.49 (95% confidence interval 0.05 to 4.72); P = 0.54) or conversion to open cholecystectomy (risk ratio 0.91 (95% confidence interval 0.69 to 1.20); P = 0.50). The total hospital stay was shorter by 4 days for early laparoscopic cholecystectomy (mean difference −4.12 (95% confidence interval −5.22 to −3.03) days; P < 0.00001). Conclusion. Early laparoscopic cholecystectomy during acute cholecystitis is safe and shortens the total hospital stay.
PMCID: PMC4123505  PMID: 25133217
15.  Salvage of Failed Protein Targets by Reductive Alkylation 
The growth of diffraction-quality single crystals is of primary importance in protein X-ray crystallography. Chemical modification of proteins can alter their surface properties and crystallization behavior. The Midwest Center for Structural Genomics (MCSG) has previously reported how reductive methylation of lysine residues in proteins can improve crystallization of unique proteins that initially failed to produce diffraction-quality crystals. Recently, this approach has been expanded to include ethylation and isopropylation in the MCSG protein crystallization pipeline. Applying standard methods, 180 unique proteins were alkylated and screened using standard crystallization procedures. Crystal structures of 12 new proteins were determined, including the first ethylated and the first isopropylated protein structures. In a few cases, the structures of native and methylated or ethylated states were obtained and the impact of reductive alkylation of lysine residues was assessed. Reductive methylation tends to be more efficient and produces the most alkylated protein structures. Structures of methylated proteins typically have higher resolution limits. A number of well-ordered alkylated lysine residues have been identified, which make both intermolecular and intramolecular contacts. The previous report is updated and complemented with the following new data; a description of a detailed alkylation protocol with results, structural features, and roles of alkylated lysine residues in protein crystals. These contribute to improved crystallization properties of some proteins.
PMCID: PMC4078742  PMID: 24590719
Chemical modification; Lysine reductive alkylation; Methylation; Ethylation; Isopropylation; Protein crystallization
16.  Mass spectrometry of membrane transporters reveals subunit stoichiometry and interactions 
Nature methods  2009;6(8):585-587.
We describe a general mass spectrometry approach to determine subunit stoichiometry and lipid binding in intact membrane protein complexes. By exploring conditions for preserving interactions during transmission into the gas phase and for optimally stripping away detergent, by subjecting the complex to multiple collisions, we release the intact complex largely devoid of detergent This enabled us to characterize both subunit stoichiometry and lipid binding in 4 membrane protein complexes.
PMCID: PMC4066579  PMID: 19578383
17.  NUP214 fusion genes in acute leukemia (Review) 
Oncology Letters  2014;8(3):959-962.
Nucleoporin 214 (NUP214), previously termed CAN, is required for cell cycle and nucleocytoplasmic transport. The genetic features and clinical implications of five NUP214-associated fusion genes are described in this review. SET-NUP214 was most frequently observed in T-cell acute lymphoblastic leukemia (T-ALL), concomitant with the elevated expression of HOXA cluster genes. Furthermore, the fusion transcript may be regarded as a potential minimal residual disease marker for SET-NUP214-positive patients. Episomal amplifications of NUP214-ABL1 are specific to T-ALL patients. The NUP214-ABL1 gene is observed in ~6% of T-ALL, in children and adults. Targeted tyrosine kinase inhibitors plus standard chemotherapy appear to present a promising treatment strategy. DEK-NUP214 is formed by the fusion of exon 2 of DEK and exon 6 of NUP214. Achieving molecular negativity of DEK-NUP214 is of great importance for individual management. SQSTM1-NUP214 and NUP214-XKR3 were only identified in one T-ALL patient and one cell line, respectively. The NUP214 fusions have significant diagnostic and therapeutic implications for leukemia patients. Additional NUP214-associated fusions require identification in future studies.
PMCID: PMC4114590  PMID: 25120641
NUP214; acute lymphoblastic leukemia; fusion gene; acute myeloid leukemia
18.  Impact of Ketamine on Learning and Memory Function, Neuronal Apoptosis and Its Potential Association with miR-214 and PTEN in Adolescent Rats 
PLoS ONE  2014;9(6):e99855.
Ketamine, an N-methyl-D-aspartate (NMDA) receptor antagonist, is used as a general pediatric anesthetic and anti-depressive drug. Recent studies suggest that ketamine enhances neuronal apoptosis in developing rats. The goal of this study is to explore whether ketamine could result in learning and memory impairment and neurodegeneration in adolescent rats, and if so, whether the effects of ketamine are associated with miR-214 and PTEN expression. Fifty-day-old SD rats were randomly divided into three groups receiving ketamine at 30, or 80 mg/kg, i.p. or saline for seven consecutive days. Twenty-four hours after the last treatment, learning and memory function were tested by the Morris water maze. The rats were then decapitated, and the brains were isolated for detection of neuronal apoptosis and protein PTEN expression by TUNEL and immunohistochemistry respectively. Expression levels of the miR-214 and PTEN in the hippocampus were measured by qRT-PCR and western blot analysis respectively. Ketamine administered to the adolescent rats at a dose of 80 mg/kg rather than the lower dose of 30 mg/kg caused learning and memory impairment, increased the number of apoptotic cells in the hippocampal CA1 region, cerebral cortex and subcortical region, decreased the miR-214 levels and increased PTEN protein expression in hippocampus. The results suggest that ketamine at a dose of 80 mg/kg in the adolescent rats is able to induce the learning and memory impairment and neurodegeneration, in which the down-regulation of miR-214 and high expression of PTEN protein may be involved.
PMCID: PMC4051782  PMID: 24914689
19.  Increased Cystic Fibrosis Transmembrane Conductance Regulators Expression and Decreased Epithelial Sodium Channel Alpha Subunits Expression in Early Abortion: Findings from a Mouse Model and Clinical Cases of Abortion 
PLoS ONE  2014;9(6):e99521.
The status of the maternal endometrium is vital in regulating humoral homeostasis and for ensuring embryo implantation. Cystic fibrosis transmembrane conductance regulators (CFTR) and epithelial sodium channel alpha subunits (ENaC-α) play an important role in female reproduction by maintaining humoral and cell homeostasis. However, it is not clear whether the expression levels of CFTR and ENaC-α in the decidual component during early pregnancy are related with early miscarriage. CBA×DBA/2 mouse mating has been widely accepted as a classical model of early miscarriage. The abortion rate associated with this mating was 33.33% in our study. The decidua of abortion-prone CBA female mice (DBA/2 mated) had higher CFTR mRNA and protein expression and lower ENaC-α mRNA and protein expression, compared to normal pregnant CBA mice (BLAB/C mated). Furthermore, increased CFTR expression and decreased ENaC-α expression were observed in the uterine tissue from women with early miscarriage, as compared to those with successful pregnancy. In conclusion, increased CFTR expression and decreased ENaC-α expression in the decidua of early abortion may relate with failure of early pregnancy.
PMCID: PMC4051784  PMID: 24914548
20.  Pharmacokinetics, clearance, and biosafety of polyethylene glycol-coated hollow gold nanospheres 
Gold nanoparticles have attracted enormous interest as potential theranostic agents. However, little is known about the long-term elimination and systemic toxicity of gold nanoparticles in the literature. Hollow gold nanospheres (HAuNS) is a class of photothermal conducting agent that have shown promises in photoacoustic imaging, photothermal ablation therapy, and drug delivery. It’s very necessary to make clear the biosafety of HAuNS for its further application.
We investigated the cytotoxicity, complement activation, and platelet aggregation of polyethylene glycol (PEG)-coated HAuNS (PEG-HAuNS, average diameter of 63 nm) in vitro and their pharmacokinetics, biodistribution, organ elimination, hematology, clinical chemistry, acute toxicity, and chronic toxicity in mice.
PEG-HAuNS did not induce detectable activation of the complement system and did not induce detectable platelet aggregation. The blood half-life of PEG-HAuNS in mice was 8.19 ± 1.4 hr. The single effective dose of PEG-HAuNS in photothermal ablation therapy was determined to be 12.5 mg/kg. PEG-HAuNS caused no adverse effects after 10 daily intravenous injections over a 2-week period at a dose of 12.5 mg/kg per injection (accumulated dose: 125 mg/kg). Quantitative analysis of the muscle, liver, spleen, and kidney revealed that the levels of Au decreased 45.2%, 28.6%, 41.7%, and 40.8%, respectively, from day 14 to day 90 after the first intravenous injection, indicating that PEG-HAuNS was slowly cleared from these organs in mice.
Our data support the use of PEG-HAuNS as a promising photothermal conducting agent.
PMCID: PMC4082425  PMID: 24886070
Hollow gold nanospheres; Toxicity; Photothermal ablation therapy
21.  Epidemiology, species distribution and outcome of nosocomial Candida spp. bloodstream infection in Shanghai 
BMC Infectious Diseases  2014;14:241.
Yeasts, mostly Candida, are important causes of bloodstream infections (BSI), responsible for significant mortality and morbidity among hospitalized patients. The epidemiology and species distribution vary from different regions. The goals of this study were to report the current epidemiology of Candida BSI in a Shanghai Teaching Hospital and estimate the impact of appropriate antifungal therapy on the outcome.
From January 2008 to December 2012, all consecutive patients who developed Candida BSI at Ruijin University Hospital were enrolled. Underlying diseases, clinical severity, species distribution, antifungal therapy and its impact on the outcome were analyzed.
A total of 121 episodes of Candida BSI were identified, with an incidence of 0.32 episodes/1,000 admissions (0.21 in 2008 and 0.42 in 2012) The proportion of candidemia caused by non-albicans species (62.8%), including C. parapsilosis (19.8%), C. tropicalis (14.9%), C. glabrata (7.4%), C. guilliermondii (5.8%), C. sake (5.0%) was higher than that of candidemia caused by C. albicans (37.2%). The overall crude 28-day mortality was 28.1% and significantly reduced with appropriate empiric antifungal therapy administered within 5 days (P = 0.006). Advanced age (OR 1.04; P = 0.014), neutropenia < 500/mm3 (OR 17.44; P < 0.001) were independent risk factors for 28-day mortality, while appropriate empiric antifungal therapy (OR 0.369; P = 0.035) was protective against 28-day mortality.
The epidemiology of candidemia in Shanghai differed from that observed in Western countries. Appropriate empiric antifungal therapy influenced the short-term survival.
PMCID: PMC4033490  PMID: 24886130
Candida spp; Bloodstream infection; Appropriate antifungal therapy; Survival
22.  Annexin A5-Functionalized Nanoparticle for Multimodal Imaging of Cell Death 
Molecular imaging  2013;12(3):182-190.
Techniques for visualizing cell death can provide noninvasive assessment of both disease states and response to therapeutic intervention. The purpose of this study was to develop and evaluate a multimodal imaging nanoplatform for the detection of cell death.
In this study, we evaluated 111In-labeled Annexin A5-conjugated core-crosslinked polymeric micelles (CCPM) for multimodal imaging of cell death in various disease models. Three different models were conducted, including tumor apoptosis, hepatic apoptosis and inflammation. Both micro-single photon emission tomography/computed tomography (µSPECT/CT) and fluorescence molecular tomography (FMT) were performed. Biodistribution and immunohistochemistry assays were carried out to validate selectivity of cell death imaging.
In all disease models, cell death was clearly visualized by both µSPECT/CT and FMT. In contrast, there was relatively low signal in the corresponding tissues of control mice. Moreover, the radioactive signal from 111In-labeled annexin A5-CCPM colocalized with its fluorescence signal, and both signals were confined to regions of dying cells.
111In-labeled annexin A5-CCPM allows visualization of cell death by both nuclear and optical techniques at whole-body level as well as at microscopic level. It has the potential to aid diagnosis of disease states or tissue responses involving abnormal cell death.
PMCID: PMC3893065  PMID: 23490444
Cell Death; Annexin A5; Polymeric Micelles; Nuclear Imaging; Fluorescence Optical Imaging
23.  The structures of cytosolic and plastid-located glutamine synthetases from Medicago truncatula reveal a common and dynamic architecture 
The experimental models of dicotyledonous cytoplasmic and plastid-located glutamine synthetases unveil a conserved eukaryotic-type decameric architecture, with subtle structural differences in M. truncatula isoenzymes that account for their distinct herbicide resistance.
The first step of nitrogen assimilation in higher plants, the energy-driven incorporation of ammonia into glutamate, is catalyzed by glutamine synthetase. This central process yields the readily metabolizable glutamine, which in turn is at the basis of all subsequent biosynthesis of nitrogenous compounds. The essential role performed by glutamine synthetase makes it a prime target for herbicidal compounds, but also a suitable intervention point for the improvement of crop yields. Although the majority of crop plants are dicotyledonous, little is known about the structural organization of glutamine synthetase in these organisms and about the functional differences between the different isoforms. Here, the structural characterization of two glutamine synthetase isoforms from the model legume Medicago truncatula is reported: the crystallographic structure of cytoplasmic GSII-1a and an electron cryomicroscopy reconstruction of plastid-located GSII-2a. Together, these structural models unveil a decameric organization of dicotyledonous glutamine synthetase, with two pentameric rings weakly connected by inter-ring loops. Moreover, rearrangement of these dynamic loops changes the relative orientation of the rings, suggesting a zipper-like mechanism for their assembly into a decameric enzyme. Finally, the atomic structure of M. truncatula GSII-1a provides important insights into the structural determinants of herbicide resistance in this family of enzymes, opening new avenues for the development of herbicide-resistant plants.
PMCID: PMC3975887  PMID: 24699643
glutamate-ammonia ligase; leguminous; herbicide resistance; Medicago truncatula
24.  Dual patch voltage clamp study of low membrane resistance astrocytes in situ 
Molecular Brain  2014;7:18.
Whole-cell patch clamp recording has been successfully used in identifying the voltage-dependent gating and conductance properties of ion channels in a variety of cells. However, this powerful technique is of limited value in studying low membrane resistance cells, such as astrocytes in situ, because of the inability to control or accurately measure the real amplitude of command voltages. To facilitate the study of ionic conductances of astrocytes, we have developed a dual patch recording method which permits membrane current and membrane potential to be simultaneously recorded from astrocytes in spite of their extraordinarily low membrane resistance. The utility of this technique is demonstrated by measuring the voltage-dependent activation of the inwardly rectifying K+ current abundantly expressed in astrocytes and multiple ionic events associated with astrocytic GABAA receptor activation. This protocol can be performed routinely in the study of astrocytes. This method will be valuable for identifying and characterizing the individual ion channels that orchestrate the electrical activity of low membrane resistance cells.
PMCID: PMC3995526  PMID: 24636341
Astrocytes; Voltage clamp; Membrane resistance; Kir4.1; GABAA receptor
25.  Preventive effects of basic fibroblast growth factor on vascular restenosis after balloon angioplasty 
The aim of the present study was to investigate whether chronic administration of basic fibroblast growth factor (bFGF) following angioplasty in a dog model of atherosclerotic iliac stenosis may restore endothelium function and prevent restenosis (RS). In total, 40 dogs with atherosclerotic stenosis of the right iliac arteries were used in the study. A total of 20 dogs underwent histological examination of the lumen areas prior to (n=10) and immediately following angioplasty (n=10). Intravenous bFGF was administered to 10 dogs (bFGF group) and an additional 10 dogs received vehicle injection (control group). Animals in the two groups were sacrificed 42 days following surgery for in vitro analysis of vascular reactivity and morphometric assessment of the histological cross-sectional areas. The bFGF group exhibited significantly greater maximal endothelium-dependent acetylcholine-induced relaxation (Emax, 43±9%) when compared with the control group (Emax, 8±6%; P<0.05). In addition, the maximal endothelium-independent response of the bFGF group to sodium nitroprusside (Emax, 90±2%) was greater than that of the control group (Emax, 60±2%; P<0.05). Six weeks following angioplasty, the lumen area in the bFGF group (2.01±0.78 mm2) was greater compared with the control group (1.0±0.10%). The lumen area decreased by 58% between immediately after angioplasty and the control group six weeks following angioplasty. Therefore, the results of the present study indicated that administration of bFGF may not only restore endothelium-dependent and -independent relaxation, but also prevent RS in dogs that have undergone angioplasty.
PMCID: PMC3991498  PMID: 24940410
basic fibroblast growth factor; angioplasty; vascular endothelium

Results 1-25 (104)