PMCC PMCC

Search tips
Search criteria

Advanced
Results 1-25 (394)
 

Clipboard (0)
None

Select a Filter Below

Journals
more »
Year of Publication
more »
1.  Characterization of the Interaction between Cadmium and Chlorpyrifos with Integrative Techniques in Incurring Synergistic Hepatoxicity 
PLoS ONE  2013;8(3):e59553.
Mixture toxicity is an important issue for the risk assessment of environmental pollutants, for which an extensive amount of data are necessary in evaluating their potential adverse health effects. However, it is very hard to decipher the interaction between compounds due to limited techniques. Contamination of heavy metals and organophosphoric insecticides under the environmental and biological settings poses substantial health risk to humans. Although previous studies demonstrated the co-occurrence of cadmium (Cd) and chlorpyrifos (CPF) in environmental medium and food chains, their interaction and potentially synergistic toxicity remain elusive thus far. Here we integrated the approaches of thin-layer chromatography and 1H NMR to study the interaction between Cd2+ and CPF in inducing hepatoxicity. A novel interaction was identified between Cd2+ and CPF, which might be the bonding between Cd2+ and nitrogen atom in the pyridine ring of CPF, or the chelation formation between one Cd2+ and two CPF molecules. The Cd-CPF complex was conferred with distinct biological fate and toxicological performances from its parental components. We further demonstrated that the joint hepatoxicity of Cd ion and CPF was chiefly due to the Cd-CPF complex-facilitated intracellular transport associated with oxidative stress.
doi:10.1371/journal.pone.0059553
PMCID: PMC3597607
2.  Abnormalities of cortical-limbic-cerebellar white matter networks may contribute to treatment-resistant depression: a diffusion tensor imaging study 
BMC Psychiatry  2013;13:72.
Background
White matter abnormalities can cause network dysfunction that underlies major depressive disorder (MDD). Diffusion tensor imaging (DTI) is used to examine the neural connectivity and integrity of the white matter. Previous studies have implicated frontolimbic neural networks in the pathophysiology of MDD. Approximately 30% of MDD patients demonstrate treatment-resistant depression (TRD). However, the neurobiology of TRD remains unclear.
Methods
We used a voxel-based analysis method to analyze DTI data in young patients with TRD (n = 30; 19 males, 11 females) compared with right-handed, age- and sex-matched healthy volunteers (n = 25; 14 males, 11 females).
Results
We found a significant decrease in fractional anisotropy (FA) (corrected, cluster size >50) in the left middle frontal gyrus (peak coordinates [−18 46–14]), left limbic lobe uncus (peak coordinates [−18 2–22]), and right cerebellum posterior lobe (peak coordinates [26–34 -40]). There was no increase in FA in any brain region in patients. We also found a significant negative correlation between mean regional FA values in the three areas and Beck Depression Inventory symptom scores.
Conclusions
We found significant differences in white matter FA in the frontal lobe, limbic lobe and cerebellum between TRD patients and controls. These data suggest that abnormalities of cortical-limbic-cerebellar white matter networks may contribute to TRD in young patients.
doi:10.1186/1471-244X-13-72
PMCID: PMC3599952  PMID: 23452374
Treatment-resistant depression; Diffusion tensor imaging; Fractional anisotropy; Voxel-based analysis method
3.  IMID: integrated molecular interaction database 
Bioinformatics  2012;28(5):747-749.
Motivation: Molecular interaction information, such as protein–protein interactions and protein–small molecule interactions, is indispensable for understanding the mechanism of biological processes and discovering treatments for diseases. Many databases have been built by manual annotation of literature to organize such information into structured form. However, most databases focus on only one type of interactions, which are often not well annotated and integrated with related functional information.
Results: In this study, we integrate molecular interaction information from literature by automatic information extraction and from manually annotated databases. We further integrate the relationships between protein/gene and other bio-entity terms including gene ontology terms, pathways, species and diseases to build an integrated molecular interaction database (IMID). Interactions can be selected by their associated probabilities. IMID allows complex and versatile queries for context-specific molecular interactions, which are not available currently in other molecular interaction databases.
Availability: The database is located at www.integrativebiology.org.
Contact: jinfeng@stat.fsu.edu
doi:10.1093/bioinformatics/bts010
PMCID: PMC3289914  PMID: 22238258
4.  Complete Genome Sequence of a Novel H9N2 Subtype Influenza Virus FJG9 Strain in China Reveals a Natural Reassortant Event 
Journal of Virology  2012;86(18):10240-10241.
A/chicken/FJ/G9/09 (FJ/G9) is an H9N2 subtype avian influenza virus (H9N2 AIV) strain causing high morbidity that was isolated from broilers in Fujian Province of China in 2009. FJ/G9 has been used as the vaccine strain against H9N2 AIV infection in Fujian Province of China. Here, we report the complete genome sequence of FJ/G9 with natural six-way reassortment, which is the most complex genotype strain in China and even in the world so far. The present findings will aid in understanding the complexity and diversity of H9N2 subtype avian influenza virus.
doi:10.1128/JVI.01623-12
PMCID: PMC3446608  PMID: 22923800
5.  Deubiquitinating enzyme BAP1 is involved in the formation and maintenance of the diapause embryos of Artemia 
Cell Stress & Chaperones  2012;17(5):577-587.
The modification of proteins by ubiquitination and deubiquitination plays an important role in various cellular processes. BRCA1-associated protein-1 (BAP1) is a deubiquitinating enzyme whose function in the control of the cell cycle requires both its deubiquitinating activity and nuclear localization. In the present study, a ubiquitin carboxyl-terminal hydrolase belonging to the BAP1 family was identified and characterized from Artemia parthenogenetica, a member of a family of brine shrimp that, under certain conditions, produce and release diapause embryos in which cell division and turnover of macromolecules are arrested. Western blot analysis and in vitro enzyme activity assay revealed ArBAP1 to be a cytoplasmic protein with typical ubiquitin hydrolase activity. Northern blot analysis revealed that ArBAP1 was abundant in the abdomen of Artemia producing diapause-destined embryos. Furthermore, by in situ hybridization, ArBAP1 was located exclusively in the embryos. In vivo knockdown of ArBAP1 by RNA interference resulted in the formation of embryos with split shells and abortive nauplii. The present findings suggest that ArBAP1, the first reported cytoplasmic BAP1, participates in the formation of diapause embryos and plays an important role in the control of cell cycle arrest in these encysted embryos.
doi:10.1007/s12192-012-0333-7
PMCID: PMC3535162  PMID: 22374320
Artemia; BAP1; Deubiquitinate; Diapause; Formation; Maintenance
6.  Use of Metabolomic Profiling in the Study of Arachidonic Acid Metabolism in Cardiovascular Disease 
Arachidonic acid is one of the pivotal signaling molecules associated with inflammation, pain and homeostatic function. Drugs specifically targeting these signaling pathways represent more than 25% of annual pharmaceutical sales worldwide. However, chronic administration of nonsteroidal anti-inflammatory drugs (NSAIDs) and rofecoxib (Vioxx), a potent cyclooxygenase-2 inhibitor, have been associated with adverse cardiovascular events. Understanding the possible mechanisms underlying these adverse events is critical for evaluating the risks and benefits of this group of drugs and for development of safer drugs. Using a powerful metabolomics approach, 20-hydroxyeicosatetraenoic acid (20-HETE) was identified among many of arachidonic acid metabolic products as a likely culprit for adverse cardiovascular side effect associated with rofecoxib and NSAIDs. In addition, using a similar metabolomic approach, epoxyeicosatrienoic acids (EETs), which are lipid mediators derived from arachidonic acid through the cytochrome P450 epoxygenase pathway, have been shown to exhibit cardioprotective effects in a murine myocardial infarction (MI) model. Inhibitors of the soluble epoxide hydrolase increase titers of epoxy fatty acids and both block and reverse cardiac hypertrophy in rodent models. These highly potent, orally available compounds may be promising for treating heart failure and other cardiovascular disease. In this review, we will summarize some of the recent advances using metabolomic profiling to gain insights into the involvement of arachidonic acid pathways in cardiovascular disease.
doi:10.1111/j.1751-7133.2010.00209.x
PMCID: PMC3583533  PMID: 21272227
7.  Sporadic Obstructive Hydrocephalus in Aqp4 Null Mice 
Journal of neuroscience research  2009;87(5):1150-1155.
Aquaporin-4 (Aqp4) is a water transport protein expressed in glia and ependymocytes in brain. We report here the unexpected occurrence of severe obstructive hydrocephalus in a random subset of Aqp4 knockout mice. Of 612 Aqp4 knockout mice produced by heterozygote–heterozygote or knockout–knockout breedings, 9.6% of offspring manifested progressive encephalomegaly. Encephalomegaly was never seen in wild-type or Aqp4 heterozygous mice. Examination of the subset encephalomegalic mice revealed marked triventricular hydrocephalus (lateral ventricle size ~500 mm3), elevated intracranial pressure (19 ± 3 vs. 6.1 ± 0.6 mm Hg), and death by age 6 weeks, with a median survival of 28 days. Intraventricular dye injection studies revealed total obstruction of the cerebral aqueduct. Evans blue extravasation studies indicated an intact blood–brain barrier in the hydrocephalic mice. Brain histology revealed reduced ventricular size and ependymocyte disorganization in some nonhydrocephalic Aqp4 null mice. Our studies establish Aqp4 deletion as a predisposing factor for the development of congenital obstructive hydrocephalus in mice. We suggest that AQP4 polymorphisms might also contribute to the development of aqueduct stenosis in humans.
doi:10.1002/jnr.21927
PMCID: PMC3582395  PMID: 18951529
aquaporin; aqueduct stenosis; Aqp4 hydrocephalus; ependyma
8.  Loss of Human Epidermal Growth Factor Receptor 2 (HER2) Expression in Metastatic Sites of HER2-Overexpressing Primary Breast Tumors 
Journal of Clinical Oncology  2011;30(6):593-599.
Purpose
We evaluated whether patients with human epidermal growth factor receptor 2 (HER2) –positive primary breast tumors had metastatic tumors that were HER2 positive (concordant) or HER2 negative (discordant). We then evaluated whether treatment with trastuzumab or chemotherapy before biopsy of the metastasis had any effect on the rate of HER2 discordance. We also compared the overall survival durations of patients with HER2-concordant and -discordant tumors.
Patients and Methods
We retrospectively identified all patients who initially had been diagnosed with HER2-positive (immunohistochemistry 3+ and/or fluorescent in situ hybridization positive) primary breast cancer between 1997 and 2008 at MD Anderson Cancer Center who also had metastatic tumor biopsy results available for review.
Results
We included 182 patients who met our criteria. Forty-three (24%) of the 182 patients with HER2-positive primary tumors had HER2-negative metastatic tumors. The HER2 discordance rates differed significantly on the basis of whether patients received chemotherapy (P = .022) but not on the basis of whether patients received trastuzumab (P = .296). Patients with discordant HER2 status had shorter overall survival than did patients with concordant HER2 status (hazard ratio [HR], 0.43; P = .003). A survival difference remained among the 67 patients who received trastuzumab (HR, 0.56; P = .083) and 101 patients who did not (HR, 0.53; P = .033) before their metastasis biopsies.
Conclusion
We confirmed that loss of HER2-positive status in metastatic tumors can occur in patients with primary HER2-positive breast cancer. Our data strongly support the need for biopsies of metastatic lesions to accurately determine patient prognosis and appropriate use of targeted therapy.
doi:10.1200/JCO.2010.33.8889
PMCID: PMC3295557  PMID: 22124109
9.  The Ellipsoidal Area Ratio (EAR): An Alternative Anisotropy Index for Diffusion Tensor Imaging 
Magnetic resonance imaging  2008;27(3):311-323.
In the processing and analysis of Diffusion Tensor Imaging (DTI) data, certain predefined morphological features of diffusion tensors are often represented as simplified scalar indices, termed Diffusion Anisotropy Indices (DAIs). When comparing tensor morphologies across differing voxels of an image, or across corresponding voxels in different images, DAIs are mathematically and statistically more tractable than are the full tensors, which are probabilistic ellipsoids consisting of 3 orthogonal vectors that each has a direction and an associated scalar magnitude. We have developed a new DAI, the “Ellipsoidal Area Ratio” (EAR), to represent the degree of anisotropy in the morphological features of a diffusion tensor. The EAR is a normalized geometrical measure of surface curvature in the 3D diffusion ellipsoid. Monte Carlo simulations and applications to the study of in vivo human data demonstrate that, at low noise levels, EAR provides a similar contrast-to-noise ratio (CNR) but a higher signal-to-noise ratio (SNR) than does fractional anisotropy (FA), which is currently the most popular anisotropy index in active use. Moreover, at the high noise levels encountered most commonly in real-world DTI datasets, EAR compared with FA is consistently much more robust to perturbations from noise and it provides a higher CNR, features useful for the analysis of DTI data that are inherently noise-sensitive.
doi:10.1016/j.mri.2008.07.018
PMCID: PMC3575168  PMID: 18835122
Diffusion Tensor Imaging (DTI); Diffusion Anisotropy Index (DAI); Ellipsoidal Area Ratio (EAR); Fractional Anisotropy (FA)
10.  In vitro release of organophosphorus acid anhydrolase from functionalized mesoporous silica against nerve agents 
Analytical Biochemistry  2011;421(2):477-481.
We report here that under different physiological conditions, biomolecular drugs can be stockpiled in a nanoporous support and afterwards can be instantly released when needed for acute responses, and the biomolecular drug molecules can also be gradually released from the nanoporous support over a long time for a complete recovery. Organophosphorus acid anhydrolase (OPAA) was spontaneously and largely entrapped in functionalized mesoporous silica (FMS) due to the dominant electrostatic interaction. The OPAA-FMS composite exhibited a burst release in pH 9.0, NaHCO3-Na2CO3 buffer system and a gradual release in pH 7.4, simulated body fluid. The binding of OPAA to NH2-FMS can result in less Trp exposure of OPAA molecules to aqueous environment. The bound OPAA in FMS displayed lower activity than the free OPAA in solution prior to the enzyme entrapment. However, the released enzyme still displayed the native conformational structure and the same high enzymatic activity as that prior to the enzyme entrapment. The in vitro results in the rabbit serum demonstrate that both OPAA-FMS and the released OPAA may be used as the medical measures against the organophosphorus nerve agents.
doi:10.1016/j.ab.2011.09.024
PMCID: PMC3274626  PMID: 22019765
Controlled release; organophosphorus acid anhydrolase; mesoporous silica; organophosphorus nerve agents
11.  MicroRNA Variants Increase the Risk of HPV-Associated Squamous Cell Carcinoma of the Oropharynx in Never Smokers 
PLoS ONE  2013;8(2):e56622.
Background
Both microRNAs and human papillomavirus (HPV) infection play an important role in the development and progression of oral squamous cell carcinoma (OSCC). In addition, microRNAs affect all facets of the immune/inflammation responses to infection, which may control HPV clearance. We thus hypothesized that microRNA polymorphisms modify the association between HPV16 seropositivity and OSCC risk.
Methods
Four single-nucleotide polymorphisms in microRNAs were genotyped and HPV16 serology was determined in 325 cases and 335 matched controls. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using univariate and multivariable logistic regression models.
Results
Overall, each polymorphism had no significant main effect on OSCC risk. Compared with the risk among individuals with both miR146 rs2910164 GG genotype and HPV16 seronegativity, risk of OSCC was increased among those with CG or CC genotype and HPV16 seronegativity (OR, 1.2; 95% CI, 0.9–1.8), GG genotype and HPV16 seropositivity (OR, 3.0; 95% CI, 1.8–5.0), and CG or CC genotype and HPV16 seropositivity (OR, 4.7; 95% CI, 2.3–9.4). Similar results were found for miR149 rs2292832, miR196 rs11614913, and miR499 rs3746444. Analyses stratified by tumor sites and smoking status showed that each polymorphism significantly increased the risk of HPV16-associated squamous cell carcinoma of the oropharynx (SCCOP), and such effect modification was particularly prominent in never smokers.
Conclusions
Our results indicate that microRNA polymorphisms modify the risk of OSCC associated with HPV16 seropositivity, particularly in patients with SCCOP and never smokers. Larger studies are needed to verify our findings.
doi:10.1371/journal.pone.0056622
PMCID: PMC3574010  PMID: 23457596
12.  Anatomical Abnormalities in Gray and White Matter of the Cortical Surface in Persons with Schizophrenia 
PLoS ONE  2013;8(2):e55783.
Background
Although schizophrenia has been associated with abnormalities in brain anatomy, imaging studies have not fully determined the nature and relative contributions of gray matter (GM) and white matter (WM) disturbances underlying these findings. We sought to determine the pattern and distribution of these GM and WM abnormalities. Furthermore, we aimed to clarify the contribution of abnormalities in cortical thickness and cortical surface area to the reduced GM volumes reported in schizophrenia.
Methods
We recruited 76 persons with schizophrenia and 57 healthy controls from the community and obtained measures of cortical and WM surface areas, of local volumes along the brain and WM surfaces, and of cortical thickness.
Results
We detected reduced local volumes in patients along corresponding locations of the brain and WM surfaces in addition to bilateral greater thickness of perisylvian cortices and thinner cortex in the superior frontal and cingulate gyri. Total cortical and WM surface areas were reduced. Patients with worse performance on the serial-position task, a measure of working memory, had a higher burden of WM abnormalities.
Conclusions
Reduced local volumes along the surface of the brain mirrored the locations of abnormalities along the surface of the underlying WM, rather than of abnormalities of cortical thickness. Moreover, anatomical features of white matter, but not cortical thickness, correlated with measures of working memory. We propose that reductions in WM and smaller total cortical surface area could be central anatomical abnormalities in schizophrenia, driving, at least partially, the reduced regional GM volumes often observed in this illness.
doi:10.1371/journal.pone.0055783
PMCID: PMC3572102  PMID: 23418459
13.  Clinical outcome observation of preoperative concurrent chemoradiotherapy/radiotherapy alone in 174 Chinese patients with local advanced cervical carcinoma 
OncoTargets and therapy  2013;6:67-74.
Objective
To study outcomes of concurrent chemoradiotherapy (CCRT) or radiotherapy (RT) alone followed by radical surgery in patients with local advanced cervical cancer.
Methods
A retrospective approach was carried out in 174 Chinese patients with International Federation of Obstetricians and Gynaecologists stage IB2–IIIB cervical carcinoma. A total of 121 patients were treated with CCRT, while the remaining 53 patients received RT alone, and the regimen of chemotherapy was weekly cisplatin (40 mg/m2). Pathological response, overall survival (OS), progression-free survival (PFS), and complications were analyzed.
Results
The median age was 45 years and the mean primary tumor diameter was 4.8 ± 1.0 cm. Pathological complete response (CR) was achieved in 53 patients (30.5%). The CR rate was relatively higher in the CCRT group (31.4% vs 28.3%, P = 0.724), particularly when tumor diameter was less than 5 cm (38.2% vs 30.8%, P = 0.623). With median follow-up of 24 months, patients with CR had improved 3-year OS (100% vs 83.6%, P = 0.018) and 3-year PFS (93.1% vs 83.2%, P = 0.035) compared to patients with residual disease. CCRT was associated with significantly improved 3-year PFS (92.0% vs 76.5%, P = 0.032) compared to RT alone in patients with tumor diameter less than 5 cm. Thirty-seven patients (21.3%) experienced more than grade 2 toxicity, and one patient (0.6%) developed grade 3 uronephrosis. Data thus indicated that pathologic response, tumor size, and lymph-node involvement were highly correlated with clinical outcomes of the local advanced cervical disease.
Conclusion
Preoperative CCRT achieved outcomes superior to RT alone, depending on the pathologic response, tumor size and lymph-node involvement as major prognostic factors.
doi:10.2147/OTT.S39495
PMCID: PMC3569376  PMID: 23404048
local advanced cervical carcinoma; concurrent chemoradiotherapy; radical hysterectomy; pelvic lymphadenectomy; prognostic factors
14.  Downregulation of PCAF by miR-181a/b provides feedback regulation to TNF-α-induced transcription of pro-inflammatory genes in liver epithelial cells1,2 
Aberrant cellular responses to pro-inflammatory cytokines, such as TNF-α, are pathogenic features in most chronic inflammatory diseases. A variety of extracellular and intracellular feedback pathways have evolved to prevent an inappropriate cellular reaction to these pro-inflammatory cytokines. Here, we report that TNF-α treatment of human and mouse cholangiocytes and hepatocytes downregulated expression of p300/CBP-associated factor (PCAF), a co-activator and an acetyltransferase that promotes histone acetylation and gene transcription. Of these upregulated microRNAs (miRNAs) in TNF-α-treated cells, miR-181a/b (miR-181a and miR-181b) suppressed translation of PCAF mRNA. Functional manipulation of miR-181a/b caused reciprocal alterations in PCAF protein expression in cultured cholangiocytes and hepatocytes. Inhibition of miR-181a/b function with anti-miRs blocked TNF-α-induced suppression of PCAF expression. Promoter recruitment of PCAF was shown to be associated with TNF-α-induced transcription of inflammatory genes. Intriguingly, pretreatment of cells with TNF-α inhibited transcription of inflammatory genes in response to subsequent TNF-α stimulation. Overexpression of PCAF or inhibition of miR-181a/b function with anti-miRs attenuated the inhibitory effects of TNF-α pretreatment on epithelial inflammatory response to subsequent TNF-α stimulation. Downregulation of PCAF and the inhibitory effects of TNF-α pretreatment on liver epithelial inflammatory response were further confirmed in a mouse model of TNF-α intraperitoneal injection. These data suggest that PCAF is a target for miR-181a/b, and downregulation of PCAF by TNF-α provides negative feedback regulation to inflammatory reactions in liver epithelial cells, a process that may be relevant to the epigenetic fine-tuning of epithelial inflammatory processes in general.
doi:10.4049/jimmunol.1101976
PMCID: PMC3262895  PMID: 22219331
miRNAs; PCAF; Negative feedback; Epithelial cells; Inflammation; TNF-α
15.  Renal distal tubule proliferation and increased aquaporin 2 level but decreased urine osmolality in db/db mouse: treatment with chromium picolinate 
Hallmark features of type 2 diabetes mellitus include glucosuria and polyuria. Further, renal aquaporin 2 is pivotal to regulation of fluid excretion and urine osmolality. Accordingly, we tested the hypothesis that the db/db mouse displays increased glucosuria and fluid excretion but reduced urine osmolality in association with decreased renal aquaporin 2 level. In addition, we examined the effect of chromium picolinate (Cr(pic)3) which is purported to improve glycemic control. The db/db mice excreted more urine in association with marked glucose excretion but lower urine osmolality than db/m control group. Light microscopic examination of renal tissue revealed proliferation of tubular structures in db/db compared to the db/m mice, a feature validated with Ki67 immunostaining. Further, these tubules showed generally similar immunostaining intensity and pattern for aquaporin 2 indicating that proliferated tubules are of distal origin. On the other hand, renal aquaporin 2 protein level was significantly higher in the db/db than db/m group. Treatment of db/db mice with Cr(pic)3 reduced plasma glucose and hemoglobin A1c (~ 15–17%, p<0.05) and Ki67 positive cells but other parameters were similar to their untreated counterparts. Collectively, these findings suggest that proliferation of renal distal tubules and increased aquaporin 2 level likely represent an adaptive mechanism to regulate fluid excretion to prevent dehydration in the setting of marked glucosuria in the db/db mouse, features not affected by Cr(pic)3 treatment. These observations are of relevance to increasing interest in developing therapeutic agents that facilitate renal glucose elimination.
doi:10.1016/j.yexmp.2011.09.015
PMCID: PMC3291811  PMID: 21983138
Diabetes; kidney; Glucosuria; Aquaporin 2; Ki67; Urine osmolality; Chromium picolinate
16.  Nanog Is an Essential Factor for Induction of Pluripotency in Somatic Cells from Endangered Felids 
BioResearch Open Access  2013;2(1):72-76.
Abstract
Nanog has an important role in pluripotency induction in bovines and snow leopards. To examine whether it was required for wild felids globally, we examined the induction of pluripotency in felids from Asia (Bengal tiger, Panthera tigris), Africa (serval, Leptailurus serval), and the Americas (jaguar, Panthera onca). Dermal fibroblasts were transduced with genes encoding the human transcription factors OCT4, SOX2, KLF4, and cMYC with or without NANOG. Both four- and five-factor induction resulted in colony formation at day 3 in all three species tested; however, we were not able to maintain colonies that were generated without NANOG beyond passage (P) 7. Five-factor induced pluripotent stem cell (iPSC) colonies from wild cats were expanded in vitro on feeder layers and were positive for alkaline phosphatase and protein expression of OCT-4, NANOG, and stage-specific embryonic antigen-4 at P4 and P14. Reverse-transcription polymerase chain reaction confirmed that all five human transgenes were transcribed at P4; however, OCT4, SOX2, and NANOG transgenes were silenced by P14. Endogenous OCT4 and NANOG transcripts were detected at P4 and P14 in all cell lines confirming successful reprogramming. At P14, the iPSCs from all three species remained euploid and differentiated in vivo and in vitro into derivatives of the three germ layers. This study describes an effective method for inducing pluripotency in three endangered wild cats from across the globe and confirms Nanog as an essential factor in the reprogramming event. Efficient production of iPSC from endangered felids creates a unique opportunity for species preservation through gamete production, nuclear transfer, embryo complementation, and future novel technologies.
doi:10.1089/biores.2012.0297
PMCID: PMC3569963
conservation; induced pluripotent stem cells; Nanog; wild cats
17.  Bayesian Inference of Spatial Organizations of Chromosomes 
PLoS Computational Biology  2013;9(1):e1002893.
Knowledge of spatial chromosomal organizations is critical for the study of transcriptional regulation and other nuclear processes in the cell. Recently, chromosome conformation capture (3C) based technologies, such as Hi-C and TCC, have been developed to provide a genome-wide, three-dimensional (3D) view of chromatin organization. Appropriate methods for analyzing these data and fully characterizing the 3D chromosomal structure and its structural variations are still under development. Here we describe a novel Bayesian probabilistic approach, denoted as “Bayesian 3D constructor for Hi-C data” (BACH), to infer the consensus 3D chromosomal structure. In addition, we describe a variant algorithm BACH-MIX to study the structural variations of chromatin in a cell population. Applying BACH and BACH-MIX to a high resolution Hi-C dataset generated from mouse embryonic stem cells, we found that most local genomic regions exhibit homogeneous 3D chromosomal structures. We further constructed a model for the spatial arrangement of chromatin, which reveals structural properties associated with euchromatic and heterochromatic regions in the genome. We observed strong associations between structural properties and several genomic and epigenetic features of the chromosome. Using BACH-MIX, we further found that the structural variations of chromatin are correlated with these genomic and epigenetic features. Our results demonstrate that BACH and BACH-MIX have the potential to provide new insights into the chromosomal architecture of mammalian cells.
Author Summary
Understanding how chromosomes fold provides insights into the complex relationship among chromatin structure, gene activity and the functional state of the cell. Recently, chromosome conformation capture based technologies, such as Hi-C and TCC, have been developed to provide a genome-wide, high resolution and three-dimensional (3D) view of chromatin organization. However, statistical methods for analyzing these data are still under development. Here we propose two Bayesian methods, BACH to infer the consensus 3D chromosomal structure and BACH-MIX to reveal structural variations of chromatin in a cell population. Applying BACH and BACH-MIX to a high resolution Hi-C dataset, we found that most local genomic regions exhibit homogeneous 3D chromosomal structures. Furthermore, spatial properties of 3D chromosomal structures and structural variations of chromatin are associated with several genomic and epigenetic features. Noticeably, gene rich, accessible and early replicated genomic regions tend to be more elongated and exhibit higher structural variations than gene poor, inaccessible and late replicated genomic regions.
doi:10.1371/journal.pcbi.1002893
PMCID: PMC3561073  PMID: 23382666
20.  The Effect of Heparin-VEGF Multilayer on the Biocompatibility of Decellularized Aortic Valve with Platelet and Endothelial Progenitor Cells 
PLoS ONE  2013;8(1):e54622.
The application of polyelectrolyte multilayer films is a new, versatile approach to surface modification of decellularized tissue, which has the potential to greatly enhance the functionality of engineered tissue constructs derived from decellularized organs. In the present study, we test the hypothesis that Heparin- vascular endothelial growth factor (VEGF) multilayer film can not only act as an antithrombotic coating reagent, but also induce proliferation of endothelial progenitor cells (EPCs) on the decellularized aortic heart valve. SEM demonstrated the adhesion and geometric deformation of platelets. The quantitative assay of platelet activation was determined by measuring the production of soluble P-selectin. Binding and subsequent release of heparin and VEGF from valve leaflets were assessed qualitatively by laser confocal scanning microscopy and quantitatively by ELISA methods. Human blood derived EPCs were cultured and the adhesion and growth of EPCs on the surface modified valvular scaffolds were assessed. The results showed that Heparin-VEGF multilayer film improved decellularized valve haemocompatibility with respect to a substantial reduction of platelet adhesion. Release of VEGF from the decellularized heart valve leaflets at physiological conditions was sustained over 5 days. In vitro biological tests demonstrated that EPCs achieved better adhesion, proliferation and migration on the coatings with Heparin-VEGF multilayer film. Combined, these results indicate that Heparin-VEGF multilayer film could be used to cover the decellularized porcine aortic valve to decrease platelet adhesion while exhibiting excellent EPCs biocompatibility.
doi:10.1371/journal.pone.0054622
PMCID: PMC3554718  PMID: 23359625
21.  S100+ cells: A new neuro-immune cross-talkers in lymph organs 
Scientific Reports  2013;3:1114.
Up to now, the ‘hardwired’ neural pathway of the neuro-immune regulation is not fully understood. Here we reported a new neural pathway which links sympathetic nerves with immune cells of the lymphoid tissues. Our results demonstrated that nerve fibers derived from superior cervical ganglion directly targeted only S100+ cells in the cervical lymph nodes. Moreover, we found co-expression of neurotransmitters such as norepinephrine, vasoactive intestinal polypeptide and neuropeptide Y in the postganglionic sympathetic nerve endings that innervate S100+ cells. Our findings suggested that S100+ cells serve as a neuro-immune cross-talker in lymph organs that may play a significant role in transmitting signals of nervous cells to targeted immune cells. The new findings provide better understanding of the cross-talk mechanism between the nervous system and the immune system.
doi:10.1038/srep01114
PMCID: PMC3552286  PMID: 23346371
22.  Serum osteocalcin level and its association with carotid atherosclerosis in patients with type 2 diabetes 
Objective
To investigate the association of serum osteocalcin with carotid atherosclerosis in patients with type 2 diabetes.
Methods
We performed a cross-sectional community-based study in metropolitan area. Serum total osteocalcin was measured by radioimmunoassay in 382 men and 435 postmenopausal women. The carotid artery intima-media thickness (IMT) and carotid plaques (PLQ) were measured by B-mode ultrasound.
Results
The crude mean of serum osteocalcin concentrations were 4.52±2.43 ng/ml for men and 5.75±2.92 ng/ml for postmenopausal women (P <0.001), respectively. Osteocalcin levels were associated inversely with age, fasting serum insulin, HOMA-IR, ALT, triglycerides, total cholesterol, LDL- cholesterol, CRP (all P<0.001) and positively with adiponectin and HOMA-B (all P<0.05). After multiple adjustment, the odds ratios (ORs) were substantially higher risk for carotid plaques (OR 1.77 for 1 SD decrease in osteocalcin, 95% CI 1.23-2.76, p=0.005). These associations remained significant after further adjustment for potential confounder.
Conclusions
Serum osteocalcin levels is an independent risk factor for carotid atherosclerosis in patients with type 2 diabetes.
doi:10.1186/1475-2840-12-22
PMCID: PMC3558414  PMID: 23342952
Osteocalcin; Intima-media thickness; Carotid atherosclerotic plaques; Atherosclerosis
23.  The Use of Propofol as a Sedative Agent in Gastrointestinal Endoscopy: A Meta-Analysis 
PLoS ONE  2013;8(1):e53311.
Objectives
To assess the efficacy and safety of propofol sedation for gastrointestinal endoscopy, we conducted a meta-analysis of randomized controlled trials (RCTs) comparing propofol with traditional sedative agents.
Methods
RCTs comparing the effects of propofol and traditional sedative agents during gastrointestinal endoscopy were found on MEDLINE, the Cochrane Central Register of Controlled Trials, and EMBASE. Cardiopulmonary complications (i.e., hypoxia, hypotension, arrhythmia, and apnea) and sedation profiles were assessed.
Results
Twenty-two original RCTs investigating a total of 1,798 patients, of whom 912 received propofol only and 886 received traditional sedative agents only, met the inclusion criteria. Propofol use was associated with shorter recovery (13 studies, 1,165 patients; WMD –19.75; 95% CI –27.65, 11.86) and discharge times (seven studies, 471 patients; WMD –29.48; 95% CI –44.13, –14.83), higher post-anesthesia recovery scores (four studies, 503 patients; WMD 2.03; 95% CI 1.59, 2.46), better sedation (nine studies, 592 patients; OR 4.78; 95% CI 2.56, 8.93), and greater patient cooperation (six studies, 709 patients; WMD 1.27; 95% CI 0.53, 2.02), as well as more local pain on injection (six studies, 547 patients; OR 10.19; 95% CI 3.93, 26.39). Effects of propofol on cardiopulmonary complications, procedure duration, amnesia, pain during endoscopy, and patient satisfaction were not found to be significantly different from those of traditional sedative agents.
Conclusions
Propofol is safe and effective for gastrointestinal endoscopy procedures and is associated with shorter recovery and discharge periods, higher post-anesthesia recovery scores, better sedation, and greater patient cooperation than traditional sedation, without an increase in cardiopulmonary complications. Care should be taken when extrapolating our results to specific practice settings and high-risk patient subgroups.
doi:10.1371/journal.pone.0053311
PMCID: PMC3540096  PMID: 23308191
24.  Human umbilical cord stem cell encapsulation in novel macroporous and injectable fibrin for muscle tissue engineering 
Acta biomaterialia  2012;9(1):4688-4697.
There has been little research on the seeding of human umbilical cord mesenchymal stem cells (hUCMSCs) in three-dimensional scaffolds for muscle tissue engineering. The objectives of this study were: (i) to seed hUCMSCs in a fibrin hydrogel containing fast-degradable microbeads (dMBs) to create macropores to enhance cell viability; and (ii) to investigate the encapsulated cell proliferation and myogenic differentiation for muscle tissue engineering. Mass fractions of 0–80% of dMBs were tested, and 35% of dMBs in fibrin was shown to avoid fibrin shrinkage while creating macropores and promoting cell viability. This construct was referred to as “dMB35”. Fibrin without dMBs was termed “dMB0”. Microbead degradation created macropores in fibrin and improved cell viability. The percentage of live cells in dMB35 reached 91% at 16 days, higher than the 81% in dMB0 (p < 0.05). Live cell density in dMB35 was 1.6-fold that of dMB0 (p < 0.05). The encapsulated hUCMSCs proliferated, increasing the cell density by 2.6 times in dMB35 from 1 to 16 days. MTT activity for dMB35 was substantially higher than that for dMB0 at 16 days (p < 0.05). hUCMSCs in dMB35 had high gene expressions of myotube markers of myosin heavy chain 1 (MYH1) and alpha-actinin 3 (ACTN3). Elongated, multinucleated cells were formed with positive staining of myogenic specific proteins including myogenin, MYH, ACTN and actin alpha 1. Moreover, a significant increase in cell fusion was detected with myogenic induction. In conclusion, hUCMSCs were encapsulated in fibrin with degradable microbeads for the first time, achieving greatly enhanced cell viability and successful myogenic differentiation with formation of multinucleated myotubes. The injectable and macroporous fibrin–dMB–hUCMSC construct may be promising for muscle tissue engineering applications.
doi:10.1016/j.actbio.2012.08.009
PMCID: PMC3535490  PMID: 22902812
Fibrin hydrogel; Fast-degradable microbeads; Human umbilical cord mesenchymal stem; cells; Injectable cell delivery; Macroporous hydrogel
25.  Using Poisson mixed-effects model to quantify transcript-level gene expression in RNA-Seq 
Bioinformatics  2011;28(1):63-68.
Motivation: RNA sequencing (RNA-Seq) is a powerful new technology for mapping and quantifying transcriptomes using ultra high-throughput next-generation sequencing technologies. Using deep sequencing, gene expression levels of all transcripts including novel ones can be quantified digitally. Although extremely promising, the massive amounts of data generated by RNA-Seq, substantial biases and uncertainty in short read alignment pose challenges for data analysis. In particular, large base-specific variation and between-base dependence make simple approaches, such as those that use averaging to normalize RNA-Seq data and quantify gene expressions, ineffective.
Results: In this study, we propose a Poisson mixed-effects (POME) model to characterize base-level read coverage within each transcript. The underlying expression level is included as a key parameter in this model. Since the proposed model is capable of incorporating base-specific variation as well as between-base dependence that affect read coverage profile throughout the transcript, it can lead to improved quantification of the true underlying expression level.
Availability and implementation: POME can be freely downloaded at http://www.stat.purdue.edu/~yuzhu/pome.html.
Contact: yuzhu@purdue.edu; zhaohui.qin@emory.edu
Supplementary information: Supplementary data are available at Bioinformatics online.
doi:10.1093/bioinformatics/btr616
PMCID: PMC3244770  PMID: 22072384

Results 1-25 (394)