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Find video protocols related to scientific articles indexed in Pubmed.
Passively mode-locked femtosecond laser with an Nd-doped La3Ga5SiO14 disordered crystal.
Opt Express
PUBLISHED: 11-18-2014
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We experimentally prove the broad emission band of Nd:LGS disordered crystal and demonstrate a diode-pumped passively mode-locked femtosecond Nd-doped La3Ga5SiO14 (Nd:LGS) laser for the first time. With a birefringent filter inserted into the cavity, the tunable continuous wave (CW) laser of over 60 nm from 1045.2 nm to 1105.3 nm is achieved, which is the widest tuning range with Nd-doped crystals to our knowledge. Further in mode-locked operation, femtosecond pulses with pulse duration of 381 fs, average output power of 75 mW and repetition rate of 134.4 MHz are obtained at the central wavelength of 1066 nm. It is suitable to be a compact seed for femtosecond laser amplifiers.
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Histone-modifying enzymes, histone modifications and histone chaperones in nucleosome assembly: Lessons learned from Rtt109 histone acetyltransferases.
Crit. Rev. Biochem. Mol. Biol.
PUBLISHED: 11-04-2014
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Abstract During DNA replication, nucleosomes ahead of replication forks are disassembled to accommodate replication machinery. Following DNA replication, nucleosomes are then reassembled onto replicated DNA using both parental and newly synthesized histones. This process, termed DNA replication-coupled nucleosome assembly (RCNA), is critical for maintaining genome integrity and for the propagation of epigenetic information, dysfunctions of which have been implicated in cancers and aging. In recent years, it has been shown that RCNA is carefully orchestrated by a series of histone modifications, histone chaperones and histone-modifying enzymes. Interestingly, many features of RCNA are also found in processes involving DNA replication-independent nucleosome assembly like histone exchange and gene transcription. In yeast, histone H3 lysine K56 acetylation (H3K56ac) is found in newly synthesized histone H3 and is critical for proper nucleosome assembly and for maintaining genomic stability. The histone acetyltransferase (HAT) regulator of Ty1 transposition 109 (Rtt109) is the sole enzyme responsible for H3K56ac in yeast. Much research has centered on this particular histone modification and histone-modifying enzyme. This Critical Review summarizes much of our current understanding of nucleosome assembly and highlights many important insights learned from studying Rtt109 HATs in fungi. We highlight some seminal features in nucleosome assembly conserved in mammalian systems and describe some of the lingering questions in the field. Further studying fungal and mammalian chromatin assembly may have important public health implications, including deeper understandings of human cancers and aging as well as the pursuit of novel anti-fungal therapies.
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Iron-Mediated Internal-Oxidant Relay Cascade Reaction: Strategy to Synthesize Fullerenooxazoles and Hydroxyfullerenyl Amides.
J. Org. Chem.
PUBLISHED: 11-04-2014
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A novel FeCl2·4H2O-mediated internal-oxidant relay cascade reaction has been developed by functionalization of O-substituted benzohydroxamic acids or N-chloro-arylamides with [60]fullerene. Depending on the nature of the N-substituted groups, fullerenooxazoles or rare hydroxyfullerenyl amides could be obtained in a straightforward and flexible manner. Such a new transformation provides a unique strategy for the synthesis of fullerenooxazoles or hydroxyfullerenyl amides.
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Generation of 73??fs pulses from a diode pumped Kerr-lens mode-locked Yb:YCa4O(BO3)3 laser.
Opt Lett
PUBLISHED: 11-01-2014
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We realized a stable Kerr-lens mode-locked operation in a Yb:YCa4O(BO3)3 laser. Pulses as short as 73 fs were generated at the central wavelength of 1043 nm, with a bandwidth of 19 nm. The femtosecond oscillator operating at a repetition rate of 110 MHz delivers an average output power of 70 mW under 3 W diode pump power. To the best of our knowledge, this is the first demonstration of a pure Kerr-lens mode-locked operation in a diode-pumped Yb:YCa4O(BO3)3 laser.
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Synthesis of Multisubstituted Pyrroles from Doubly Activated Cyclopropanes Using an Iron-Mediated Oxidation Domino Reaction.
J. Org. Chem.
PUBLISHED: 10-31-2014
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An alternative route has been developed for the construction of multisubstituted pyrrole derivatives from readily available, doubly activated cyclopropanes and anilines using an iron-mediated oxidation domino reaction (i.e., sequential ring-opening, cyclization, and dehydrogenation reactions). This reaction uses readily available reactants and is tolerant of a broad range of substrates, with the desired products being formed in good to excellent yields.
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Diabetic cardiomyopathy and its prevention by nrf2: current status.
Diabetes Metab J
PUBLISHED: 10-29-2014
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Diabetic cardiomyopathy (DCM), as one of the major cardiac complications in diabetic patients, is known to related with oxidative stress that is due to a severe imbalance between reactive oxygen species (ROS) and/or reactive nitrogen species (RNS) generation and their clearance by antioxidant defense systems. Transcription factor nuclear factor NF-E2-related factor 2 (Nrf2) plays an important role in maintaining the oxidative homeostasis by regulating multiple downstream antioxidants. Diabetes may up-regulate several antioxidants in the heart as a compensative mechanism at early stage, but at late stage, diabetes not only generates extra ROS and/or RNS but also impairs antioxidant capacity in the heart, including Nrf2. In an early study, we have established that Nrf2 protect the cardiac cells and heart from high level of glucose in vitro and hyperglycemia in vivo, and in the following study demonstrated the significant down-regulation of cardiac Nrf2 expression in diabetic animals and patients. Using Nrf2-KO mice or Nrf2 inducers, blooming evidence has indicated the important protection by Nrf2 from cardiac pathogenesis in the diabetes. Therefore, this brief review summarizes the status of studies on Nrf2's role in preventing DCM and even other complications, the need for new and safe Nrf2 inducer screening and the precaution for the undesirable side of Nrf2 under certain conditions.
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Aberrant miR199a-5p/caveolin1/PPAR? axis in hepatic steatosis.
J. Mol. Endocrinol.
PUBLISHED: 10-13-2014
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The prevalence of non-alcoholic fatty liver disease (NAFLD), a condition characterized by an excessive accumulation of triglycerides (TGs) in hepatocytes, has dramatically increased globally during recent decades. MicroRNAs (miRs) have been suggested to play crucial roles in many complex diseases and lipid metabolism. Our results indicated that miR199a-5p was remarkably upregulated in free fatty acid (FA)-treated hepatocytes. To investigate the role of miR199a-5p in the pathogenesis of fatty liver and the potential mechanism by which miR199a-5p regulates NAFLD, we first transfected two hepatocyte cell lines, HepG2 and AML12 cells, with agomiR199a-5p or antagomiR199a-5p. Our results indicated that miR199a-5p overexpression exacerbated deposition of FA and inhibited ATP levels and mitochondrial DNA (mtDNA) contents. Consistently, suppression of miR199a-5p partially alleviated deposition of FA and increased ATP levels and mtDNA contents. Moreover, miR199a-5p suppressed the expression of mitochondrial FA ?-oxidation-related genes through inhibition of caveolin1 (CAV1) and the related peroxisome proliferator-activated receptor alpha (PPAR?) pathway. Furthermore, suppression of CAV1 gene expression by CAV1 siRNA inhibited the PPAR? signalling pathway. Finally, we examined the expression of miR199a-5p in liver samples derived from mice fed a high-fat diet, db/db mice, ob/ob mice and NAFLD patients, and found that miR199a-5p was upregulated while CAV1 and PPARA were downregulated in these systems, which was strongly indicative of the essential role of miR199a-5p in NAFLD. In summary, miR199a-5p plays a vital role in lipid metabolism, mitochondrial activity and mitochondrial ?-oxidation in liver. Upregulated miR199a-5p in hepatocytes may contribute to impaired FA ?-oxidation in mitochondria and aberrant lipid deposits, probably via CAV1 and the PPAR? pathway.
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Free fatty acid receptor 2, a candidate target for type 1 diabetes, induces cell apoptosis through ERK signaling.
J. Mol. Endocrinol.
PUBLISHED: 10-08-2014
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Recent reports have highlighted the roles of free fatty acid receptor 2 (FFAR2) in the regulation of metabolic and inflammatory processes. However, the potential function of FFAR2 in type 1 diabetes (T1D) remains unexplored. Our results indicated that the mRNA level of FFAR2 was upregulated in peripheral blood mononuclear cells of T1D patients. The human FFAR2 promoter regions were cloned, and luciferase reporter assays revealed that NF?B activation induced FFAR2 expression. Furthermore, we showed that FFAR2 activation by overexpression induced cell apoptosis through ERK signaling. Finally, treatment with the FFAR2 agonists acetate or phenylacetamide 1 attenuated the inflammatory response in multiple-low-dose streptozocin-induced diabetic mice, and improved the impaired glucose tolerance. These results indicate that FFAR2 may play a protective role by inducing apoptosis of infiltrated macrophage in the pancreas through its feedback upregulation and activation, thus, in turn, improving glucose homeostasis in diabetic mice. These findings highlight FFAR2 as a potential therapeutic target of T1D, representing a link between immune response and glucose homeostasis.
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Dimethyl sulfoxide participant iron-mediated cascade oxidation/?-formylation reaction of substituted 2,3-dihydropyrroles under air and protonic acid free condition.
J. Org. Chem.
PUBLISHED: 08-18-2014
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An efficient and Brønsted acid free one-pot protocol to directly generate structurally sophisticated ?-formylpyrrole derivatives in moderate to good yields has been demonstrated, involving an iron-mediated domino oxidation/formylation reaction of readily available 2,3-dihydro-1H-pyrroles in dimethyl sulfoxide and air atmosphere, in which dimethyl sulfoxide acts as the formyl donor. A possible mechanism is presented.
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Optical temperature sensing based on the near-infrared emissions from Nd³?/Yb³? codoped CaWO?.
Opt Lett
PUBLISHED: 08-15-2014
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Under a 980 nm diode laser excitation, the near-infrared (NIR) emissions from Nd3+:4F7/2, 4F5/2, and 4F3/2 states in Nd3+/Yb3+ codoped CaWO4 powder were studied at temperatures ranging from 303 to 873 K. As the temperature increased, the NIR luminescence intensity was significantly enhanced and nearly 190-fold enhancement was achieved at 873 K compared with that at 303 K. By using the fluorescence intensity ratio technique, the thermometry behaviors through the NIR emissions were investigated. The results illustrate that the sensitivity and the accuracy achieved here are much higher than temperature sensors based on other rare earth ion doped materials.
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Heavy traffic feasible hybrid intracycle and cyclic sleep for power saving in 10G-EPON.
ScientificWorldJournal
PUBLISHED: 08-11-2014
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Energy consumption in optical access networks costs carriers substantial operational expense (OPEX) every year and is one of contributing factors for the global warming. To reduce energy consumption in the 10-gigabit Ethernet passive optical network (10G-EPON), a hybrid intracycle and cyclic sleep mechanism is proposed in this paper. Under heavy traffic load, optical network units (ONUs) can utilize short idle slots within each scheduling cycle to enter intracycle sleep without postponing data transmission. In this way, energy conservation is achieved even under heavy traffic load with quality of service (QoS) guarantee. Under light traffic load, ONUs perform long cyclic sleep for several scheduling cycles. The adoption of cyclic sleep instead of intracycle sleep under light traffic load can reduce unnecessary frequent transitions between sleep and full active work caused by using intracycle sleep. Further, the Markov chain of the proposed mechanism is established. The performances of the proposed mechanism and existing approaches are analyzed quantitatively based on the chain. For the proposed mechanism, power saving ability with QoS guarantee even under heavy traffic and better power saving performance than existing approaches are verified by the quantitative analysis. Moreover, simulations validate the above conclusions based on the chain.
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Sulforaphane prevents the development of cardiomyopathy in type 2 diabetic mice probably by reversing oxidative stress-induced inhibition of LKB1/AMPK pathway.
J. Mol. Cell. Cardiol.
PUBLISHED: 07-11-2014
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Type 2 diabetes mellitus (T2DM)-induced cardiomyopathy is associated with cardiac oxidative stress, inflammation, and remodeling. Sulforaphane (SFN), an isothiocyanate naturally presenting in widely consumed vegetables, particularly broccoli, plays an important role in cardiac protection from diabetes. We investigated the effect of SFN on T2DM-induced cardiac lipid accumulation and subsequent cardiomyopathy. Male C57BL/6J mice were fed a high-fat diet for 3months to induce insulin resistance, followed by a treatment with 100mg/kg body-weight streptozotocin to induce hyperglycemia; we referred to it as the T2DM mouse model. Other age-matched mice were fed a normal diet as control. T2DM and control mice were treated with or without 4-month SFN at 0.5mg/kg daily five days a week. At the study's end, cardiac function was assessed. SFN treatment significantly attenuated cardiac remodeling and dysfunction induced by T2DM. SFN treatment also significantly inhibited cardiac lipid accumulation, measured by Oil Red O staining, and improved cardiac inflammation oxidative stress and fibrosis, shown by down-regulating diabetes-induced PAI-1, TNF-?, CTGF, TGF-?, 3-NT, and 4-HNE expression. Elevated 4-HNE resulted in the increase of 4-HNE-LKB1 adducts that should inhibit LKB1 and subsequent AMPK activity. SFN upregulated the expression of Nrf2 and its downstream genes, NQO1 and HO-1, decreased 4-HNE-LKB1 adducts and then reversed diabetes-induced inhibition of LKB1/AMPK and its downstream targets, including sirtuin 1, PGC-1?, phosphorylated acetyl-CoA carboxylase, carnitine palmitoyl transferase-1, ULK1, and light chain-3 II. These results suggest that SFN treatment to T2DM mice may attenuate the cardiac oxidative stress-induced inhibition of LKB1/AMPK signaling pathway, thereby preventing T2DM-induced lipotoxicity and cardiomyopathy.
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Financial protection effects of modification of China's New Cooperative Medical Scheme on rural households with chronic diseases.
BMC Health Serv Res
PUBLISHED: 07-09-2014
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Several years have passed since the rural New Cooperative Medical Scheme (NCMS) in China was established and policies kept continuous improvement. Its policies on chronic diseases vary by county but have certain shared characteristics. Following this modification of medical insurance policy, this study reassesses the provision of insurance against expenditure on chronic diseases in rural areas, and analyzes its effect on impoverishment.
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High-dose diosgenin reduces bone loss in ovariectomized rats via attenuation of the RANKL/OPG ratio.
Int J Mol Sci
PUBLISHED: 07-04-2014
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The aim of this study was to evaluate effect of diosgenin (DG) on rats that had osteoporosis-like features induced by ovariectomy (OVX). Seventy-two six-month-old female Wistar rats were subjected to either ovariectomy (n = 60) or Sham operation (SHAM group, n = 12). Beginning at one week post-ovariectomy, the OVX rats were treated with vehicle (OVX group, n = 12), estradiol valerate (EV group, n = 12), or DG at three doses (DG-L, -M, -H group, n = 12, respectively). After a 12-week treatment, administration of EV or DG-H inhibited OVX-induced weight gain, and administration of EV or DG-H or DG-M had a significantly uterotrophic effect. Bone mineral density (BMD) and indices of bone histomorphometry of tibia were measured. Levels of protein and mRNA expression of osteoprotegerin (OPG) and receptor activator of nuclear factor kappa-B ligand (RANKL) in tibia were evaluated by immunohistochemistry and in situ hybridization. Our results show that DG at a high dose (DG-H) had a significant anti-osteoporotic effect compared to OVX control. DG-H treatment down-regulated expression of RANKL and up-regulated expression of OPG significantly in tibia from OVX rats compared to control, and thus lowered the RANKL/OPG ratio. This suggests that the anti-osteoporotic effect of DG might be associated with modulating the RANKL/OPG ratio and DG had potential to be developed as alternative therapeutic agents of osteoporosis induced by postmenopause.
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Protection by sulforaphane from type 1 diabetes-induced testicular apoptosis is associated with the up-regulation of Nrf2 expression and function.
Toxicol. Appl. Pharmacol.
PUBLISHED: 06-11-2014
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Diabetes-induced testicular apoptosis is predominantly due to increased oxidative stress. The nuclear factor-erythroid 2-related factor 2 (Nrf2), as a master transcription factor in controlling anti-oxidative systems, is able to be induced by sulforaphane (SFN). To examine whether SFN prevents testicular apoptosis, type 1 diabetic mouse model was induced with multiple low-dose streptozotocin. Diabetic and age-matched control mice were treated with and without SFN at 0.5mg/kg daily in five days of each week for 3months and then kept until 6months. Diabetes significantly increased testicular apoptosis that was associated with endoplasmic reticulum stress and mitochondrial cell death pathways, shown by the increased expression of C/EBP homologous protein (CHOP), cleaved caspase-12, Bax to Bcl2 expression ratio, and cleaved caspase-3. Diabetes also significantly increased testicular oxidative damage, inflammation and fibrosis, and decreased germ cell proliferation. All these diabetic effects were significantly prevented by SFN treatment for the first 3months, and the protective effect could be sustained at 3months after SFN treatment. SFN was able to up-regulate Nrf2 expression and function. The latter was reflected by the increased phosphorylation of Nrf2 at Ser40 and expression of Nrf2 downstream antioxidants at mRNA and protein levels. These results suggest that type 1 diabetes significantly induced testicular apoptosis and damage along with increasing oxidative stress and cell death and suppressing Nrf2 expression and function. SFN is able to prevent testicular oxidative damage and apoptosis in type 1 diabetes mice, which may be associated with the preservation of testicular Nrf2 expression and function under diabetic condition.
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Molecular Signature in Human Cumulus Cells Related to Embryonic Developmental Potential.
Reprod Sci
PUBLISHED: 06-06-2014
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Identification of criteria for embryo quality is required to improve the clinical outcome of in vitro fertilization. The aim of this study was to determine the gene expression profile of cumulus cells (CC) surrounding the oocyte as biomarkers for embryonic developmental potential. CCs from single oocytes were analysed using DNA microarrays. Gene expression profiles of CC surrounding the oocyte associated with good embryonic quality were analyzed. We observed that CCs issued from oocytes that developed into embryos with a good morphology had significantly different gene expression profile from those with bad morphology. These results were confirmed by quantitative RT-PCR. The gene expression profiling of human CC correlates with embryo potential. Our findings suggest anon-invasive approach, offering a new potential strategy for competent embryo selection.
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High-throughput generation of an activation-tagged mutant library for functional genomic analyses in tobacco.
Planta
PUBLISHED: 05-27-2014
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Tobacco (Nicotiana tabacum L.) is an ideal model system for molecular biological and genetic studies. In this study, activation tagging was used to generate approximately 100,000 transgenic tobacco plants. Southern blot analysis indicated that there were 1.6 T-DNA inserts per line on average in our transformed population. The phenotypes observed include abnormalities in leaf and flower morphology, plant height, flowering time, branching, and fertility. Among 6,000 plants in the T0 generation, 57 displayed obvious phenotypes. Among 4,105 lines in the T1 generation, 311 displayed abnormal phenotypes. Fusion primer and nested integrated PCR was used to identify 963 independent genomic loci of T-DNA insertion sites in 1,257 T1 lines. The distribution of T-DNA insertions was non-uniform and correlated well with the predicted gene density along each chromosome. The insertions were biased toward genic regions and noncoding regions within 5 kb of a gene. Fifteen plants that showed the same phenotype as their parent with a dominant pattern in the T2 generation were chosen randomly to detect the expression levels of genes adjacent to the T-DNA integration sites by semi-quantitative RT-PCR. Fifteen candidate genes were identified. Activation was observed in 7 out of the 15 adjacent genes, including one that was located 13.1 kb away from the enhancer sequence. The activation-tagged population described in this paper will be a highly valuable resource for tobacco functional genomics research using both forward and reverse genetic approaches.
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Prevalence of extended treatment in pulmonary tuberculosis patients receiving first-line therapy and its association with recurrent tuberculosis in Beijing, China.
Trans. R. Soc. Trop. Med. Hyg.
PUBLISHED: 05-25-2014
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In China, it is known that extended treatment is given to patients with pulmonary TB after they have successfully completed 6 months of first-line treatment. This practice is not officially reported to the National Tuberculosis Control Programme, so there are no data on its prevalence, its possible benefits in terms of preventing recurrent disease or the costs. This study aimed to provide information, from a single TB dispensary in Beijing, China, on the prevalence of extended anti-TB treatment and its relationship with recurrent TB.
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Sulforaphane reduction of testicular apoptotic cell death in diabetic mice is associated with the upregulation of Nrf2 expression and function.
Am. J. Physiol. Endocrinol. Metab.
PUBLISHED: 05-06-2014
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Diabetes-induced testicular cell death is due predominantly to oxidative stress. Nuclear factor (erythroid-derived 2)-like 2 (Nrf2) is an important transcription factor in controlling the antioxidative system and is inducible by sulforaphane (SFN). To test whether SFN prevents diabetes-induced testicular cell death, an insulin-defective stage of type 2 diabetes (IDS-T2DM) was induced in mice. This was accomplished by feeding them a high-fat diet (HFD) for 3 mo to induce insulin resistance and then giving one intraperitoneal injection of streptozotocin to induce hyperglycemia while age-matched control mice were fed a normal diet (ND). IDS-T2DM and ND-fed control mice were then further subdivided into those with or without 4-mo SFN treatment. IDS-T2DM induced significant increases in testicular cell death presumably through receptor and mitochondrial pathways, shown by increased ratio of Bax/Bcl2 expression and cleavage of caspase-3 and caspase-8 without significant change of endoplasmic reticulum stress. Diabetes also significantly increased testicular oxidative damage and inflammation. All of these diabetic effects were significantly prevented by SFN treatment with upregulated Nrf2 expression. These results suggest that IDS-T2DM induces testicular cell death presumably through caspase-8 activation and mitochondria-mediated cell death pathways and also by significantly downregulating testicular Nrf2 expression and function. SFN upregulates testicular Nrf2 expression and its target antioxidant expression, which was associated with significant protection of the testis from IDS-T2DM-induced germ cell death.
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Pharmacologic inhibition of histone demethylation as a therapy for pediatric brainstem glioma.
Nat. Med.
PUBLISHED: 04-24-2014
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Pediatric brainstem gliomas often harbor oncogenic K27M mutation of histone H3.3. Here we show that GSKJ4 pharmacologic inhibition of K27 demethylase JMJD3 increases cellular H3K27 methylation in K27M tumor cells and demonstrate potent antitumor activity both in vitro against K27M cells and in vivo against K27M xenografts. Our results demonstrate that increasing H3K27 methylation by inhibiting K27 demethylase is a valid therapeutic strategy for treating K27M-expressing brainstem glioma.
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Prevalence, correlates and recognition of depression in Chinese inpatients with cancer.
Gen Hosp Psychiatry
PUBLISHED: 04-18-2014
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To determine the prevalence, correlates and recognition rates of depressive disorders (DDs) in Chinese inpatients with cancer.
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Adaptive covariance estimation of non-stationary processes and its application to infer dynamic connectivity from fMRI.
IEEE Trans Biomed Circuits Syst
PUBLISHED: 04-17-2014
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Time-varying covariance is an important metric to measure the statistical dependence between non-stationary biological processes. Time-varying covariance is conventionally estimated from short-time data segments within a window having a certain bandwidth, but it is difficult to choose an appropriate bandwidth to estimate covariance with different degrees of non-stationarity. This paper introduces a local polynomial regression (LPR) method to estimate time-varying covariance and performs an asymptotic analysis of the LPR covariance estimator to show that both the estimation bias and variance are functions of the bandwidth and there exists an optimal bandwidth to minimize the mean square error (MSE) locally. A data-driven variable bandwidth selection method, namely the intersection of confidence intervals (ICI), is adopted in LPR for adaptively determining the local optimal bandwidth that minimizes the MSE. Experimental results on simulated signals show that the LPR-ICI method can achieve robust and reliable performance in estimating time-varying covariance with different degrees of variations and under different noise scenarios, making it a powerful tool to study the dynamic relationship between non-stationary biomedical signals. Further, we apply the LPR-ICI method to estimate time-varying covariance of functional magnetic resonance imaging (fMRI) signals in a visual task for the inference of dynamic functional brain connectivity. The results show that the LPR-ICI method can effectively capture the transient connectivity patterns from fMRI.
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Pneumocystis jirovecii Rtt109, a novel drug target for Pneumocystis pneumonia in immunosuppressed humans.
Antimicrob. Agents Chemother.
PUBLISHED: 04-14-2014
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Pneumocystis pneumonia (PcP) is a significant cause of morbidity and mortality in immunocompromised patients. In humans, PcP is caused by the opportunistic fungal species Pneumocystis jirovecii. Progress in Pneumocystis research has been hampered by a lack of viable in vitro culture methods, which limits laboratory access to human-derived organisms for drug testing. Consequently, most basic drug discovery research for P. jirovecii is performed using related surrogate organisms such as Pneumocystis carinii, which is derived from immunosuppressed rodents. While these studies provide useful insights, important questions arise about interspecies variations and the relative utility of identified anti-Pneumocystis agents against human P. jirovecii. Our recent work has identified the histone acetyltransferase (HAT) Rtt109 in P. carinii (i.e., PcRtt109) as a potential therapeutic target for PcP, since Rtt109 HATs are widely conserved in fungi but are absent in humans. To further address the potential utility of this target in human disease, we now demonstrate the presence of a functional Rtt109 orthologue in the clinically relevant fungal pathogen P. jirovecii (i.e., PjRtt109). In a fashion similar to that of Pcrtt109, Pjrtt109 restores H3K56 acetylation and genotoxic resistance in rtt109-null yeast. Recombinant PjRtt109 is an active HAT in vitro, with activity comparable to that of PcRtt109 and yeast Rtt109. PjRtt109 HAT activity is also enhanced by the histone chaperone Asf1 in vitro. PjRtt109 and PcRtt109 showed similar low micromolar sensitivities to two reported small-molecule HAT inhibitors in vitro. Together, these results demonstrate that PjRtt109 is a functional Rtt109 HAT, and they support the development of anti-Pneumocystis agents directed at Rtt109-catalyzed histone acetylation as a novel therapeutic target for human PcP.
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N,N'-Bis[3,5-bis(trifluoromethyl)phenyl]thiourea: a privileged motif for catalyst development.
Org. Biomol. Chem.
PUBLISHED: 04-08-2014
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Over the last decade, the use of (thio)urea derivatives as organocatalysts in organic chemistry has increased rapidly. One of the key features is their ability to activate substrates and subsequently stabilize partially developing negative charges (e.g., oxyanions) in the transition states employing explicit double hydrogen bonding. Among (thio)urea-based catalysts, N,N'-bis[3,5-bis(trifluoromethyl)phenyl]thiourea developed by Schreiner's group (abbreviated here as Schreiner's thiourea) has played a very important role in the development of H-bond organocatalysts. Nowadays it is used extensively in promoting organic transformations, and the 3,5-bis(trifluoromethyl)phenyl motif thereof is used ubiquitously in H-bond catalysts. This review summarizes the key developments of Schreiner's thiourea-mediated reactions with the aim to further expand the applications of (thio)urea-based catalysts.
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Luminescence and photosensitivity of gadolinium labeled hematoporphyrin monomethyl ether.
Opt Express
PUBLISHED: 03-26-2014
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Photodynamic therapy for deep-lying lesions needs an appropriate imaging modality, precise evaluation of tissue oxygen and an effective photosensitizer. Gadolinium based metalloporphyrins Gd(III)-HMME is proposed in this study as a potential multifunctional theranostic agent, as photosensitizer, ratiometric oxygen sensor and MRI contrast agent. The time resolved spectroscopy revealed the luminescence peak of Gd(III)-HMME at 710 and 779 nm with a lifetime of 64 ?s in oxygen-free methanol to be phosphorescent. This phosphorescence is strongly dependent on dissolved oxygen concentration. Its intensity in oxygen saturated methanol solution is 21% of that in deoxygenated solution. The singlet oxygen quantum yields ?? of HMME and Gd(III)-HMME in air saturated methanol solution were determined to be 0.79 and 0.40 respectively using comparative spectra method. These phenomena indicate that the oxygen sensibility and production of singlet oxygen of Gd(III)-HMME can fulfill the requirement of PDT treatment.
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One of the distinctive properties of ionic liquids over molecular solvents and inorganic salts: enhanced basicity stemming from the electrostatic environment and "free" microstructure.
J Phys Chem B
PUBLISHED: 03-24-2014
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The basicity of ionic liquids (ILs) underlies many important IL-based processes including the dissolution and conversion of cellulose, the capture of CO2, and metal catalysis. In this work, we have disclosed the nature of the basicity of ILs, i.e., the difference between the basicity of IL and the basicity of the molecular solvent and inorganic salt, through a quantitative electrostatic and electronic analysis of the molecular surface for the first time. The results reveal one of the distinctive properties of ILs (enhanced basicity over molecular solvents and inorganic salts with the same basic site) stemming from their special electrostatic environment and microstructure. The enhancement is significant, from either the electrostatic aspect or the covalent aspect of basicity. The peculiar electrostatic environment of ILs leads to stronger basicity than similar molecular solvents, and the relatively freer microstructure of ILs contributes to the enhancement of basicity over their inorganic analogues. These results are highly instructive for better understanding the unique value of ILs and designing novel ILs to improve the efficiency of basicity-related processes.
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The magnolia bioactive constituent 4-O-methylhonokiol protects against high-fat diet-induced obesity and systemic insulin resistance in mice.
Oxid Med Cell Longev
PUBLISHED: 03-19-2014
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Obesity is caused by a combination of both genetic and environmental risks. Disruption in energy balance is one of these risk factors. In the present study, the preventive effect on high-fat diet- (HFD-) induced obesity and insulin resistance in mice by Magnolia bioactive constituent 4-O-methylhonokiol (MH) was compared with Magnolia officinalis extract BL153. C57BL/6J mice were fed by normal diet or by HFD with gavage-administered vehicle, BL153, low-dose MH, and high-dose MH simultaneously for 24 weeks, respectively. Either MH or BL153 slightly inhibited body-weight gain of mice by HFD feeding although the food intake had no obvious difference. Body fat mass and the epididymal white adipose tissue weight were also mildly decreased by MH or BL153. Moreover, MH significantly lowered HFD-induced plasma triglyceride, cholesterol levels and activity of alanine transaminase (ALT), liver weight and hepatic triglyceride level, and ameliorated hepatic steatosis. BL153 only significantly reduced ALT and liver triglyceride level. Concurrently, low-dose MH improved HFD-induced hyperinsulinemia and insulin resistance. Furthermore, the infiltration of mast cells in adipose tissue was decreased in MH or in BL153 treatment. These results suggested that Magnolia bioactive constituent MH might exhibit potential benefits for HFD-induced obesity by improvement of lipid metabolism and insulin resistance.
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Imaging the pair-correlated HNCO photodissociation: the NH(a1?) + CO(X1?+) channel.
J Phys Chem A
PUBLISHED: 03-19-2014
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The NH(a(1)?) + CO(X(1)?(+)) product channel for the photodissociation of HNCO at 201 nm was investigated using the sliced velocity map ion imaging technique with the detection of NH(a(1)?) products via (2 + 1) resonance enhanced multiphoton ionization (REMPI). Images were measured for the NH(a(1)?) rotational states in the ground and vibrational excited states (v = 0 and 1). Correlation between the NH(a(1)?) and CO rovibrational state distributions were determined from these images. Experimental results show that the vibrational distribution of the CO fragment in the NH(a(1)?) + CO(X(1)?(+)) channel peaks at v = 1. The negative anisotropy parameter measured for the NH(a(1)?) (v = 0 and 1|j) products indicates a direct dissociation process for the N-C bond cleavage in the S1 state. A bimodal CO rotational distribution was observed, suggesting that HNCO dissociates in the S1 state in two distinctive pathways.
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An automated and fast approach to detect single-trial visual evoked potentials with application to brain-computer interface.
Clin Neurophysiol
PUBLISHED: 03-02-2014
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This study aims (1) to develop an automated and fast approach for detecting visual evoked potentials (VEPs) in single trials and (2) to apply the single-trial VEP detection approach in designing a real-time and high-performance brain-computer interface (BCI) system.
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Two rice authentic histidine phosphotransfer proteins, OsAHP1 and OsAHP2, mediate cytokinin signaling and stress responses in rice.
Plant Physiol.
PUBLISHED: 02-27-2014
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Cytokinin plays an important role in plant development and stress tolerance. Studies of Arabidopsis (Arabidopsis thaliana) have demonstrated that cytokinin acts through a two-component system that includes a histidine (His) kinase, a His phosphotransfer protein (HP), and a response regulator. Phylogenetic analyses have revealed the conservation of His kinases but lineage-specific expansion of HPs and response regulators in rice (Oryza sativa). However, whether the functions of rice HPs have diverged remains unknown. In this study, two rice authentic HPs (OsAHP1 and OsAHP2) were knocked down simultaneously via RNA interference (RNAi), and the transgenic OsAHP-RNAi plants exhibited phenotypes expected for a deficiency in cytokinin signaling, including dwarfism with reduced internode lengths, enhanced lateral root growth, early leaf senescence, and reduced tiller numbers and fertility under natural conditions. The OsAHP-RNAi seedlings were also hyposensitive to exogenous cytokinin. Furthermore, OsAHP-RNAi seedlings were hypersensitive to salt treatment but resistant to osmotic stress relative to wild-type plants. These results indicate that OsAHPs function as positive regulators of the cytokinin signaling pathway and play different roles in salt and drought tolerance in rice.
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The Ddc1-Mec3-Rad17 sliding clamp regulates histone-histone chaperone interactions and DNA replication-coupled nucleosome assembly in budding yeast.
J. Biol. Chem.
PUBLISHED: 02-25-2014
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The maintenance of genome integrity is regulated in part by chromatin structure and factors involved in the DNA damage response pathway. Nucleosome assembly is a highly regulated process that restores chromatin structure after DNA replication, DNA repair, and gene transcription. During S phase the histone chaperones Asf1, CAF-1, and Rtt106 coordinate to deposit newly synthesized histones H3-H4 onto replicated DNA in budding yeast. Here we describe synthetic genetic interactions between RTT106 and the DDC1-MEC3-RAD17 (9-1-1) complex, a sliding clamp functioning in the S phase DNA damage and replication checkpoint response, upon treatment with DNA damaging agents. The DNA damage sensitivity of rad17? rtt106? cells depends on the function of Rtt106 in nucleosome assembly. Epistasis analysis reveals that 9-1-1 complex components interact with multiple DNA replication-coupled nucleosome assembly factors, including Rtt106, CAF-1, and lysine residues of H3-H4. Furthermore, rad17? cells exhibit defects in the deposition of newly synthesized H3-H4 onto replicated DNA. Finally, deletion of RAD17 results in increased association of Asf1 with checkpoint kinase Rad53, which may lead to the observed reduction in Asf1-H3 interaction in rad17? mutant cells. In addition, we observed that the interaction between histone H3-H4 with histone chaperone CAF-1 or Rtt106 increases in cells lacking Rad17. These results support the idea that the 9-1-1 checkpoint protein regulates DNA replication-coupled nucleosome assembly in part through regulating histone-histone chaperone interactions.
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Growth inhibition effect of HMME-mediated PDT on hepatocellular carcinoma HepG2 cells.
Lasers Med Sci
PUBLISHED: 02-23-2014
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Photodynamic therapy (PDT) is considered a promising new strategy for liver cancer treatment. Three elements of PDT--optical output power, irradiation time, and photosensitizer concentration--play important roles in promoting cell death. This research aimed to characterize the effects of hematoporphyrin monomethyl ether (HMME)-based PDT on hepatocellular carcinoma cells HepG2 and thus elucidate the relationship between cell death and the three elements mentioned earlier. Furthermore, in this study, we present a parameter that represents the cumulative effects of these elements. The accumulation of HMME in HepG2 cells was observed by fluorescence microscopy. The absorption spectrum of HMME was detected using fluorescence spectral analysis. The viability of the treated cells was determined using the MTT assay, and cell apoptosis was evaluated using flow cytometry. We found that the fluorescence intensity was positively correlated with the incubation time for up to 2 h. The cell growth inhibition rate was significantly high and gradually increased with increasing concentrations of HMME or increasing light intensity, which was calculated as optical output power × irradiation time. Further analysis revealed an e-exponential decay of the cell survival rate to the product of the HMME concentration and the light intensity. We defined the product as parameter B (B = optical output power × irradiation time × HMME concentration). Similarly, the rate of cell apoptosis showed roughly e-exponential growth to parameter B. In conclusion, HMME-mediated PDT can significantly kill HepG2 cells, and the killing effect was related to the cumulative effects of the optical output power, the irradiation time, and the HMME concentration. Therefore, the newly defined parameter B, as a comprehensive physical quantity, may be of great significance for the regulation of light and photosensitizer according to patient-specific conditions in clinical practice.
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BL153 partially prevents high-fat diet induced liver damage probably via inhibition of lipid accumulation, inflammation, and oxidative stress.
Oxid Med Cell Longev
PUBLISHED: 02-20-2014
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The present study was to investigate whether a magnolia extract, named BL153, can prevent obesity-induced liver damage and identify the possible protective mechanism. To this end, obese mice were induced by feeding with high fat diet (HFD, 60% kcal as fat) and the age-matched control mice were fed with control diet (10% kcal as fat) for 6 months. Simultaneously these mice were treated with or without BL153 daily at 3 dose levels (2.5, 5, and 10?mg/kg) by gavage. HFD feeding significantly increased the body weight and the liver weight. Administration of BL153 significantly reduced the liver weight but without effects on body weight. As a critical step of the development of NAFLD, hepatic fibrosis was induced in the mice fed with HFD, shown by upregulating the expression of connective tissue growth factor and transforming growth factor beta 1, which were significantly attenuated by BL153 in a dose-dependent manner. Mechanism study revealed that BL153 significantly suppressed HFD induced hepatic lipid accumulation and oxidative stress and slightly prevented liver inflammation. These results suggest that HFD induced fibrosis in the liver can be prevented partially by BL153, probably due to reduction of hepatic lipid accumulation, inflammation and oxidative stress.
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Iron-catalyzed vinylogous aldol condensation of Biginelli products and its application toward pyrido[4,3-d]pyrimidinones.
J. Org. Chem.
PUBLISHED: 02-18-2014
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A novel iron-catalyzed vinylogous aldol condensation of Biginelli products with aryl aldehydes has been developed for the syntheses of potential bioactive (E)-6-arylvinyl-dihydropyrimidin-2(1H)-ones. These materials are valuable synthetic precursors to drug-like pyrido[4,3-d]pyrimidine derivatives. The amide group at the 5-position of the dihydropyrimidin-2(1H)-ones played an important role in the vinylogous aldol condensation reaction.
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Magnolia extract (BL153) protection of heart from lipid accumulation caused cardiac oxidative damage, inflammation, and cell death in high-fat diet fed mice.
Oxid Med Cell Longev
PUBLISHED: 02-16-2014
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Magnolia as an herbal material obtained from Magnolia officinalis has been found to play an important role in anti-inflammation, antioxidative stress, and antiapoptosis. This study was designed to investigate the effect of Magnolia extract (BL153) on obesity-associated lipid accumulation, inflammation, oxidative stress, and apoptosis in the heart. C57BL/6 mice were fed a low- (10 kcal% fat) or high-fat (60 kcal% fat) diet for 24 weeks to induce obesity. These mice fed with high-fat diet (HFD) were given a gavage of vehicle, 2.5, 5, or 10 mg/kg body weight BL153 daily. The three doses of BL153 treatment slightly ameliorated insulin resistance without decrease of body weight gain induced by HFD feeding. BL153 at 10 mg/kg slightly attenuated a mild cardiac hypertrophy and dysfunction induced by HFD feeding. Both 5 mg/kg and 10 mg/kg of BL153 treatment significantly inhibited cardiac lipid accumulation measured by Oil Red O staining and improved cardiac inflammation and oxidative stress by downregulating ICAM-1, TNF-?, PAI-1, 3-NT, and 4-HNE. TUNEL staining showed that BL153 treatment also ameliorated apoptosis induced by mitochondrial caspase-3 independent cell death pathway. This study demonstrates that BL153 attenuates HFD-associated cardiac damage through prevention of HFD-induced cardiac lipid accumulation, inflammation, oxidative stress, and apoptosis.
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Highly sensitive optical thermometry based on upconversion emissions in Tm3+/Yb3+ codoped LiNbO3 single crystal.
Opt Lett
PUBLISHED: 02-04-2014
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Under 980 nm excitation, upconversion emissions originating from 3F(2,3)?3H(6) and 3H(4)?3H(6) transitions of Tm3+ ion in LiNbO3 single crystal were studied as a function of temperature in the range of 323-773 K. The 3F(2,3) and 3H(4) levels of Tm3+ ion are confirmed to be thermally coupled levels. By using fluorescence intensity ratio technique, the sensitivity of optical temperature sensor achieved in our work is higher than other reported temperature sensors. Additionally, this optical temperature sensor is well suited to high operating temperature. Tm3+/Yb3+ codoped LiNbO3 is a promising candidate for fabricating excellent optical temperature sensors.
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Synthesis of [60]fullerene-fused tetrahydroazepinones and azepinonimines via Cu(OAc)2-promoted N-heteroannulation reaction.
Org. Lett.
PUBLISHED: 01-29-2014
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A convenient and efficient Cu(OAc)2-mediated N-heteroannulation reaction of [60]fullerene with N-sulfonylated o-amino-aromatic methyl ketones or O-alkyl oximes has been reported for the synthesis of novel and scarce [60]fullerene-fused tetrahydroazepinones and -azepinonimines in a highly selective manner. Moreover, a possible mechanism involving two pathways is proposed on the basis of the experimental observations.
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The role of Nrf2-mediated pathway in cardiac remodeling and heart failure.
Oxid Med Cell Longev
PUBLISHED: 01-26-2014
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Heart failure (HF) is frequently the consequence of sustained, abnormal neurohormonal, and mechanical stress and remains a leading cause of death worldwide. The key pathophysiological process leading to HF is cardiac remodeling, a term referring to maladaptation to cardiac stress at the molecular, cellular, tissue, and organ levels. HF and many of the conditions that predispose one to HF are associated with oxidative stress. Increased generation of reactive oxygen species (ROS) in the heart can directly lead to increased necrosis and apoptosis of cardiomyocytes which subsequently induce cardiac remodeling and dysfunction. Nuclear factor-erythroid-2- (NF-E2-) related factor 2 (Nrf2) is a transcription factor that controls the basal and inducible expression of a battery of antioxidant genes and other cytoprotective phase II detoxifying enzymes that are ubiquitously expressed in the cardiovascular system. Emerging evidence has revealed that Nrf2 and its target genes are critical regulators of cardiovascular homeostasis via the suppression of oxidative stress, which is the key player in the development and progression of HF. The purpose of this review is to summarize evidence that activation of Nrf2 enhances endogenous antioxidant defenses and counteracts oxidative stress-associated cardiac remodeling and HF.
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Occipital anaplastic oligodendroglioma with multiple organ metastases after a short clinical course: a case report and literature review.
Diagn Pathol
PUBLISHED: 01-21-2014
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It is generally believed that malignant gliomas never metastasize outside the central nervous system (CNS). However, the notion that oligodendrogliomas (OGDs) cells cannot spread outside CNS is being challenged.
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Sulforaphane attenuation of type 2 diabetes-induced aortic damage was associated with the upregulation of Nrf2 expression and function.
Oxid Med Cell Longev
PUBLISHED: 01-06-2014
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Type 2 diabetes mellitus (T2DM) significantly increases risk for vascular complications. Diabetes-induced aorta pathological changes are predominantly attributed to oxidative stress. Nuclear factor E2-related factor-2 (Nrf2) is a transcription factor orchestrating antioxidant and cytoprotective responses to oxidative stress. Sulforaphane protects against oxidative damage by increasing Nrf2 expression and its downstream target genes. Here we explored the protective effect of sulforaphane on T2DM-induced aortic pathogenic changes in C57BL/6J mice which were fed with high-fat diet for 3 months, followed by a treatment with streptozotocin at 100 mg/kg body weight. Diabetic and nondiabetic mice were randomly divided into groups with and without 4-month sulforaphane treatment. Aorta of T2DM mice exhibited significant increases in the wall thickness and structural derangement, along with significant increases in fibrosis (connective tissue growth factor and transforming growth factor), inflammation (tumor necrosis factor-? and vascular cell adhesion molecule 1), oxidative/nitrative stress (3-nitrotyrosine and 4-hydroxy-2-nonenal), apoptosis, and cell proliferation. However, these pathological changes were significantly attenuated by sulforaphane treatment that was associated with a significant upregulation of Nrf2 expression and function. These results suggest that sulforaphane is able to upregulate aortic Nrf2 expression and function and to protect the aorta from T2DM-induced pathological changes.
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Genotypic diversity analysis of Mycobacterium tuberculosis strains collected from Beijing in 2009, using spoligotyping and VNTR typing.
PLoS ONE
PUBLISHED: 01-01-2014
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Tuberculosis (TB) is a serious problem in China. While there have been some studies on the nationwide genotyping of Mycobacterium tuberculosis (M. tuberculosis), there has been little detailed research in Beijing, the capital of China, which has a huge population. Here, M. tuberculosis clinical strains collected in Beijing during 2009 were genotyped by classical methods.
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Opposing effects of PI3K/Akt and Smad-dependent signaling pathways in NAG-1-induced glioblastoma cell apoptosis.
PLoS ONE
PUBLISHED: 01-01-2014
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Nonsteroidal anti-inflammatory drug (NSAID) activated gene-1 (NAG-1) is a divergent member of the transforming growth factor-beta (TGF-?) superfamily. NAG-1 plays remarkable multifunctional roles in controlling diverse physiological and pathological processes including cancer. Like other TGF-? family members, NAG-1 can play dual roles during cancer development and progression by negatively or positively modulating cancer cell behaviors. In glioblastoma brain tumors, NAG-1 appears to act as a tumor suppressor gene; however, the precise underlying mechanisms have not been well elucidated. In the present study, we discovered that overexpression of NAG-1 induced apoptosis in U87 MG, U118 MG, U251 MG, and T98G cell lines via the intrinsic mitochondrial pathway, but not in A172 and LN-229 cell lines. NAG-1 could induce the phosphorylation of PI3K/Akt and Smad2/3 in all six tested glioblastoma cell lines, except Smad3 phosphorylation in A172 and LN-229 cell lines. In fact, Smad3 expression and its phosphorylation were almost undetectable in A172 and LN-229 cells. The PI3K inhibitors promoted NAG-1-induced glioblastoma cell apoptosis, while siRNAs to Smad2 and Smad3 decreased the apoptosis rate. NAG-1 also stimulated the direct interaction between Akt and Smad3 in glioblastoma cells. Elevating the level of Smad3 restored the sensitivity to NAG-1-induced apoptosis in A172 and LN-229 cells. In conclusion, our results suggest that PI3K/Akt and Smad-dependent signaling pathways display opposing effects in NAG-1-induced glioblastoma cell apoptosis.
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Changes of spontaneous oscillatory activity to tonic heat pain.
PLoS ONE
PUBLISHED: 01-01-2014
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Transient painful stimuli could induce suppression of alpha oscillatory activities and enhancement of gamma oscillatory activities that also could be greatly modulated by attention. Here, we attempted to characterize changes in cortical activities during tonic heat pain perception and investigated the influence of directed/distracted attention on these responses. We collected 5-minute long continuous Electroencephalography (EEG) data from 38 healthy volunteers during four conditions presented in a counterbalanced order: (A) resting condition; (B) innoxious-distracted condition; (C) noxious-distracted condition; (D) noxious-attended condition. The effects of tonic heat pain stimulation and selective attention on oscillatory activities were investigated by comparing the EEG power spectra among the four experimental conditions and assessing the relationship between spectral power difference and subjective pain intensity. The change of oscillatory activities in condition D was characterized by stable and persistent decrease of alpha oscillation power over contralateral-central electrodes and widespread increase of gamma oscillation power, which were even significantly correlated with subjective pain intensity. Since EEG responses in the alpha and gamma frequency band were affected by attention in different manners, they are likely related to different aspects of the multidimensional sensory experience of pain. The observed contralateral-central alpha suppression (conditions D vs. B and D vs. C) may reflect primarily a top-down cognitive process such as attention, while the widespread gamma enhancement (conditions D vs. A) may partly reflect tonic pain processing, representing the summary effects of bottom-up stimulus-related and top-down subject-driven cognitive processes.
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Treatment with Rhizoma Dioscoreae extract has protective effect on osteopenia in ovariectomized rats.
ScientificWorldJournal
PUBLISHED: 01-01-2014
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The aims of this study were to evaluate the osteoprotective effect of aqueous extract from Rhizoma Dioscoreae (RDE) on rats with ovariectomy- (OVX-) induced osteopenia. Our results show that RDE could inhibit bone loss of OVX rats after a 12-week treatment. The microarray analysis showed that 68 genes were upregulated and that 100 genes were downregulated in femurs of the RDE group rats compared to those in the OVX group. The Ingenuity Pathway Analysis (IPA) showed that several downregulated genes had the potential to code for proteins that were involved in the Wnt/ ? -catenin signaling pathway (Sost, Lrp6, Tcf7l2, and Alpl) and the RANKL/RANK signaling pathway (Map2k6 and Nfatc4). These results revealed that the mechanism for an antiosteopenic effect of RDE might lie in the synchronous inhibitory effects on both the bone formation and the bone resorption, which is associated with modulating the Wnt/ ? -catenin signaling and the RANKL/RANK signaling.
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New method for measuring time-resolved spectra of lanthanide emission using square-wave excitation.
Rev Sci Instrum
PUBLISHED: 12-03-2013
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A method using modulated continuous wave (CW) visible laser to measure time-resolved fluorescence spectra of trivalent rare-earth ions has been developed. Electro-optic modulator was used to modulate the CW pumping laser with a rise time of 2 ?s. CW Nd(3+) lasers were used as examples to present the method. Upconversion dynamic process of Ho(3+) was studied utilizing a 532 nm CW laser. Quantum cutting dynamic process from Tb(3+) to Yb(3+) was analyzed by a 473 nm CW laser. This method can be applied to any CW laser such as He-Ne laser, Ar(+) laser, Kr(+) laser, Ti:sapphire laser, etc.
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Single-trial laser-evoked potentials feature extraction for prediction of pain perception.
Conf Proc IEEE Eng Med Biol Soc
PUBLISHED: 10-11-2013
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Pain is a highly subjective experience, and the availability of an objective assessment of pain perception would be of great importance for both basic and clinical applications. The objective of the present study is to develop a novel approach to extract pain-related features from single-trial laser-evoked potentials (LEPs) for classification of pain perception. The single-trial LEP feature extraction approach combines a spatial filtering using common spatial pattern (CSP) and a multiple linear regression (MLR). The CSP method is effective in separating laser-evoked EEG response from ongoing EEG activity, while MLR is capable of automatically estimating the amplitudes and latencies of N2 and P2 from single-trial LEP waveforms. The extracted single-trial LEP features are used in a Naïve Bayes classifier to classify different levels of pain perceived by the subjects. The experimental results show that the proposed single-trial LEP feature extraction approach can effectively extract pain-related LEP features for achieving high classification accuracy.
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Time-varying correlation coefficients estimation and its application to dynamic connectivity analysis of fMRI.
Conf Proc IEEE Eng Med Biol Soc
PUBLISHED: 10-11-2013
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Exploration of the dynamics of functional brain connectivity based on the correlation coefficients of functional magnetic resonance imaging (fMRI) data is important for understanding the brain mechanisms. Because fMRI data are time-varying in nature, the functional connectivity shows substantial fluctuations and dynamic characteristics. However, an effective method for estimating time-varying functional connectivity is lacking, which is mainly due to the difficulty in choosing an appropriate window to localize the time-varying correlation coefficients (TVCC). This paper introduces a novel method for adaptively estimating the TVCC of non-stationary signals and studies its application to infer dynamic functional connectivity of fMRI data in a visual task. The proposed method employs a sliding window having a certain bandwidth to estimate the TVCC locally and the window bandwidths are selected adaptively by a local plug-in rule to minimize the mean squared error. The results show that the functional connectivity changes in the visual task are transient, which suggests that simply assuming sustained connectivity changes during task period might not be sufficient to capture dynamic connectivity changes induced by tasks.
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Single-trial detection of visual evoked potentials by common spatial patterns and wavelet filtering for brain-computer interface.
Conf Proc IEEE Eng Med Biol Soc
PUBLISHED: 10-11-2013
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Event-related potentials (ERPs) are widely used in brain-computer interface (BCI) systems as input signals conveying a subjects intention. A fast and reliable single-trial ERP detection method can be used to develop a BCI system with both high speed and high accuracy. However, most of single-trial ERP detection methods are developed for offline EEG analysis and thus have a high computational complexity and need manual operations. Therefore, they are not applicable to practical BCI systems, which require a low-complexity and automatic ERP detection method. This work presents a joint spatial-time-frequency filter that combines common spatial patterns (CSP) and wavelet filtering (WF) for improving the signal-to-noise (SNR) of visual evoked potentials (VEP), which can lead to a single-trial ERP-based BCI.
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MicroRNA-21 expression is associated with overall survival in patients with glioma.
Diagn Pathol
PUBLISHED: 10-04-2013
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MicroRNA-21 has been proved to be associated with glioma proliferation and invasion; thus, we sought to clarify the clinical value of miR-21 expression in glioma tissues with WHO grade I to IV.
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Ablation of LGR4 promotes energy expenditure by driving white-to-brown fat switch.
Nat. Cell Biol.
PUBLISHED: 09-24-2013
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Obesity occurs when excess energy accumulates in white adipose tissue (WAT), whereas brown adipose tissue (BAT), specialized for energy expenditure through thermogenesis, potently counteracts obesity. Factors that induce brown adipocyte commitment and energy expenditure would be a promising defence against adiposity. Here, we show that Lgr4 homozygous mutant (Lgr4(m/m)) mice show reduced adiposity and resist dietary and leptin mutant-induced obesity with improved glucose metabolism. Lgr4(m/m) mice show a striking increase in energy expenditure, and exhibit brown-like adipocytes in WAT depots with higher expression of BAT and beige cell markers. Furthermore, Lgr4 ablation potentiates brown adipocyte differentiation from the stromal vascular fraction of epididymal WAT, partially through retinoblastoma 1 gene (Rb1) reduction. A functional low-frequency human LGR4 variant (A750T) has been associated with body mass index in a Chinese obese-versus-control study. Our results identify an important role for LGR4 in energy balance and body weight control through regulating the white-to-brown fat transition.
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Shell thickness dependence of upconversion luminescence of ?-NaYF4:Yb, Er/?-NaYF4 core-shell nanocrystals.
Opt Lett
PUBLISHED: 08-14-2013
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NaYF4:Yb, Er/NaYF4 core-shell nanocrystals with different thickness shells were synthesized. The correlation between shell thickness and upconversion (UC) luminescence intensity was investigated experimentally and theoretically. We found that the UC fluorescence intensity of the core-shell nanocrystals is enhanced exponentially with shell thickness (d) in the form of (1-0.9 exp(-d/d0). For our core-shell nanocrystals, the d0 was determined as about 5.5 nm, corresponding to an enhancement of about 12 times for the 540 nm emission intensity. The d0 may be treated as the optimized shell thickness, which represents a balance between the conflict requirements of strong UC fluorescence intensity and small total crystal size for bioapplications.
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A lesson learned from the H3.3K27M mutation found in pediatric glioma: a new approach to the study of the function of histone modifications in vivo?
Cell Cycle
PUBLISHED: 07-10-2013
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Glioblastoma (GBM) is the most aggressive primary brain tumor in human. Recent studies on high-grade pediatric GBM have identified two recurrent mutations (K27M and G34R/V) in genes encoding histone H3 (H3F3A for H3.3 and HIST1H3B for H3.1). The two histone H3 mutations are mutually exclusive and give rise to tumors in different brain compartments. Recently, we and others have shown that the histone H3 K27M mutation specifically altered the di- and tri-methylation of endogenous histone H3 at Lys27. Genome-wide studies using ChIP-seq on H3.3K27M patient samples indicate a global reduction of H3K27me3 on chromatin. Remarkably, we also found a dramatic enrichment of H3K27me3 and EZH2 (the catalytic subunit H3K27 methyltransferase) at hundreds of gene loci in H3.3K27M patient cells. Here, we discuss potential mechanisms whereby H3K27me3 is enriched at chromatin loci in cells expressing the H3.3K27M mutation and report effects of Lys-to-Met mutations of other well-studied lysine residues of histone H3.1/H3.3 and H4 on the corresponding endogenous lysine methylation. We suggest that mutation(s) on histones may be found in a variety of human diseases, and the expression of mutant histones may help to address the function of histone lysine methylation and possibly other modifications in mammalian cells.
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PP1?, PP1? and Wip-1 regulate H4S47 phosphorylation and deposition of histone H3 variant H3.3.
Nucleic Acids Res.
PUBLISHED: 07-04-2013
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Phosphorylation of histone H4 serine 47 (H4S47ph) is catalyzed by Pak2, a member of the p21-activated serine/threonine protein kinase (Pak) family and regulates the deposition of histone variant H3.3. However, the phosphatase(s) involved in the regulation of H4S47ph levels was unknown. Here, we show that three phosphatases (PP1?, PP1? and Wip1) regulate H4S47ph levels and H3.3 deposition. Depletion of each of the three phosphatases results in increased H4S47ph levels. Moreover, PP1?, PP1? and Wip1 bind H3-H4 in vitro and in vivo, whereas only PP1? and PP1?, but not Wip1, interact with Pak2 in vivo. These results suggest that PP1?, PP1? and Wip1 regulate the levels of H4S47ph through directly acting on H4S47ph, with PP1? and PP1? also likely regulating the activity of Pak2. Finally, depletion of PP1?, PP1? and Wip1 leads to increased H3.3 occupancy at candidate genes tested, elevated H3.3 deposition and enhanced association of H3.3 with its chaperones HIRA and Daxx. These results reveal a novel role of three phosphatases in chromatin dynamics in mammalian cells.
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Salt-enhanced removal of 2-ethyl-1-hexanol from aqueous solutions by adsorption on activated carbon.
J Colloid Interface Sci
PUBLISHED: 06-29-2013
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2-Ethyl-1-hexanol has extensive industrial applications in solvent extraction, however, in view of its potential pollution to environment, the removal and recovery of 2-ethyl-1-hexanol is considered an essential step toward its sustainable use in the future. In this work, we report the removal of 2-ethyl-1-hexanol from aqueous solutions containing salts in high concentrations by adsorption on a coal-based activated carbon. Adsorption thermodynamics showed that the experimental isotherms were conformed well to the Langmuir equation. Also it was found that inorganic salts, i.e. MgCl2 and CaCl2 in high concentration significantly enhanced the adsorption capacity from 223 mg/g in the deionized water to 277 mg/g in a saline water. This phenomenon of adsorption enhancement could be ascribed to the salt-out effect. Kinetic analysis indicated that adsorption kinetics follows the pseudo-second-order equation and the adsorption rate constants increase with the salt concentration. The dynamic breakthrough volume and adsorbed amount of 2-ethyl-1-hexanol were significantly elevated when the salt is present in the water. The dynamic saturated adsorption amount increased from 218.3mg/g in the deionized water to 309.5mg/g in a salt lake brine. The Tomas model was well applied to predict the breakthrough curves and determine the characteristics parameters of the adsorption column.
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Synthesis and characterization of cellulose 3,5-dimethylphenylcarbamate silica hybrid spheres for enantioseparation of chiral ?-blockers.
J Chromatogr A
PUBLISHED: 06-25-2013
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A cellulose derivative-based chiral stationary phase (CSP) is considered one of the most widely applied CSPs due to its powerful enantioseparation ability. The high loading capacity and mechanical strength of CSPs are crucial for their application in preparative chromatography, such as a simulated moving bed. Compared to traditional cellulose-based CSPs that have been adsorbed onto chromatographic supports, organic-inorganic hybrid CSPs exhibit a potentially higher loading capacity and mechanical strength by increasing the density of chiral recognition groups. A hybrid cellulose 3,5-dimethylphenylcarbamate chiral stationary phase (organic/inorganic: 70/30, w/w) was prepared via a sol-gel method and characterized with several analytical techniques, including Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and (29)Si cross polarization/magic angle spinning nuclear magnetic resonance ((29)Si CP/MAS NMR). In addition, the as-synthesized hybrid chiral silica spheres were treated with an end-capping process to mask the residual silica hydroxyl groups. Compared to a commercial Chiralpak IB column, better separation of ?-blocker drugs, including pindolol (selectivity of 5.55), metoprolol (2.30), propranolol (1.96), bisoprolol (1.74) and atenolol (1.46), on the end-capped CSP was achieved using liquid chromatography, which suggests that the packing material synthesized in this work has sufficient chiral discriminating ability for the effective separation of ?-blocker drugs.
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Semen Astragali Complanati- and Rhizoma Cibotii-enhanced bone formation in osteoporosis rats.
BMC Complement Altern Med
PUBLISHED: 06-13-2013
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Growing evidence shows that herb medicines have some anti-osteoporotic effects, the mechanism underlying is unknown. This study aims to investigate the therapeutic effect of Chinese herb supplements on rats that had osteoporosis-like symptom induced by ovariectomy (OVX).
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A Cul4 E3 ubiquitin ligase regulates histone hand-off during nucleosome assembly.
Cell
PUBLISHED: 05-12-2013
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Nucleosome assembly following DNA replication and gene transcription is important to maintain genome stability and epigenetic information. Newly synthesized histones H3-H4 first bind histone chaperone Asf1 and are then transferred to other chaperones for nucleosome assembly. However, it is unknown how H3-H4 is transferred from the Asf1-H3-H4 complex to other chaperones because Asf1 binds H3-H4 with high affinity. Here, we show that yeast Rtt101(Mms1) E3 ubiquitin ligase preferentially binds and ubiquitylates new histone H3 acetylated at lysine 56. Inactivation of Rtt101 or mutating H3 lysine residues ubiquitylated by the Rtt101(Mms1) ligase impairs nucleosome assembly and promotes Asf1-H3 interactions. Similar phenotypes occur in human cells in which the ortholog of Rtt101(Mms1), Cul4A(DDB1), is depleted. These results indicate that the transfer of H3-H4 from the Asf1-H3-H4 complex to other histone chaperones is regulated by a conserved E3 ligase and provide evidence for crosstalk between histone acetylation and ubiquitylation in nucleosome assembly.
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Target expression of Staphylococcus enterotoxin A from an oncolytic adenovirus suppresses mouse bladder tumor growth and recruits CD3+ T cell.
Tumour Biol.
PUBLISHED: 05-07-2013
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We recently engineered an oncolytic adenovirus (PPE3-SEA) that expresses the superantigen, Staphylococcus enterotoxin A (SEA), and that has enhanced tumor specificity because the telomerase reverse transcriptase and hypoxia-inducible factor promoters regulate expression of E1A and E1B genes, respectively. Here, we evaluated the PPE3-SEA adenovirus anti-tumor activity against MB49 mouse bladder cancer cell proliferation in vitro and in vivo. PPE3-SEA infection of murine MB49 cells in vitro induced cytopathic effects, and significant expression of SEA mRNA and protein, as measured by RT-PCR and western blot, respectively. Subcutaneous MB29 bladder tumors were established in syngeneic C57BL/6 mice. After 10 days, tumors were injected with either oncolytic virus or PBS. Tumor dimensions were measured on days 1, 3, 5, 7, 9, and 11 post-treatment and tumor volumes were calculated. One of eight PPE3-SEA-treated mice had no tumor by day 9. PPE3-SEA treated group had significantly lower mean tumor volume beginning on day 5 post-treatment (p < 0.01), more fibrous tissue in the tumor, and increased presence of infiltrating CD3+ T cells than those of the control group. Gross appearance and histologic sections from the livers and kidneys of the PPE3-SEA-treated group were similar to those of the control group. In conclusion, oncolytic adenoviruses can provide a novel delivery vehicle for SEA to tumor sites, and PPE3-SEA warrants further study as a potential anti-tumor agent for bladder cancer.
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High frequency of the X-chromosome inactivation in young female patients with high-grade glioma.
Diagn Pathol
PUBLISHED: 04-30-2013
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Gliomas are common tumors and high-grade ones account for 62% of primary malignant brain tumors. Though current evidence have suggested that inherited risks play a role in glioma susceptibility, it was conveyed that glioma was such a complex disease, and the direct genetic contribution to glioma risk factors and its relation to other factors should be discussed more deeply. X-chromosome inactivation (XCI) is the mechanism by which gene dosage equivalence is achieved between female mammals with two X chromosomes and male mammals with a single X chromosome. As skewed XCI has been linked to development of some solid tumors, including ovarian, breast, and pulmonary and esophageal carcinomas, it is challenging to elucidate the relation of skewed XCI to high-grade gliomas development.
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The histone H3.3K27M mutation in pediatric glioma reprograms H3K27 methylation and gene expression.
Genes Dev.
PUBLISHED: 04-19-2013
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Recent studies have identified a Lys 27-to-methionine (K27M) mutation at one allele of H3F3A, one of the two genes encoding histone H3 variant H3.3, in 60% of high-grade pediatric glioma cases. The median survival of this group of patients after diagnosis is ?1 yr. Here we show that the levels of H3K27 di- and trimethylation (H3K27me2 and H3K27me3) are reduced globally in H3.3K27M patient samples due to the expression of the H3.3K27M mutant allele. Remarkably, we also observed that H3K27me3 and Ezh2 (the catalytic subunit of H3K27 methyltransferase) at chromatin are dramatically increased locally at hundreds of gene loci in H3.3K27M patient cells. Moreover, the gain of H3K27me3 and Ezh2 at gene promoters alters the expression of genes that are associated with various cancer pathways. These results indicate that H3.3K27M mutation reprograms epigenetic landscape and gene expression, which may drive tumorigenesis.
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Efficacy and safety of tadalafil monotherapy for lower urinary tract symptoms secondary to benign prostatic hyperplasia: a meta-analysis.
Urol. Int.
PUBLISHED: 04-15-2013
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To evaluate the efficacy and safety of tadalafil monotherapy for lower urinary tract symptoms secondary to benign prostatic hyperplasia (LUTS/BPH).
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RTEL1 tagging SNPs and haplotypes were associated with glioma development.
Diagn Pathol
PUBLISHED: 04-06-2013
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As glioma ranks as the first most prevalent solid tumors in primary central nervous system, certain single-nucleotide polymorphisms (SNPs) may be related to increased glioma risk, and have implications in carcinogenesis. The present case-control study was carried out to elucidate how common variants contribute to glioma susceptibility. Ten candidate tagging SNPs (tSNPs) were selected from seven genes whose polymorphisms have been proven by classical literatures and reliable databases to be tended to relate with gliomas, and with the minor allele frequency (MAF)>5% in the HapMap Asian population. The selected tSNPs were genotyped in 629 glioma patients and 645 controls from a Han Chinese population using the multiplexed SNP MassEXTEND assay calibrated. Two significant tSNPs in RTEL1 gene were observed to be associated with glioma risk (rs6010620, P=0.0016, OR: 1.32, 95% CI: 1.11-1.56; rs2297440, P=0.001, OR: 1.33, 95% CI: 1.12-1.58) by ?2 test. It was identified the genotype "GG" of rs6010620 acted as the protective genotype for glioma (OR, 0.46; 95% CI, 0.31-0.7; P=0.0002), while the genotype "CC" of rs2297440 as the protective genotype in glioma (OR, 0.47; 95% CI, 0.31-0.71; P=0.0003). Furthermore, haplotype "GCT" in RTEL1 gene was found to be associated with risk of glioma (OR, 0.7; 95% CI, 0.57-0.86; Fishers P=0.0005; Pearsons P=0.0005), and haplotype "ATT" was detected to be associated with risk of glioma (OR, 1.32; 95% CI, 1.12-1.57; Fishers P=0.0013; Pearsons P=0.0013). Two single variants, the genotypes of "GG" of rs6010620 and "CC" of rs2297440 (rs6010620 and rs2297440) in the RTEL1 gene, together with two haplotypes of GCT and ATT, were identified to be associated with glioma development. And it might be used to evaluate the glioma development risks to screen the above RTEL1 tagging SNPs and haplotypes.
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Decreased serum 5-oxoproline in TB patients is associated with pathological damage of the lung.
Clin. Chim. Acta
PUBLISHED: 03-19-2013
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Tuberculosis (TB) is a serious world-wide health problem, causing millions of deaths every year. Metabolomics is a relatively new approach to identify disease specific biomarkers. However, there is little information available on metabolite biomarkers in TB. In this study, we used gas chromatography/time-of-flight mass spectrometry (GC/TOF-MS) to identify serum metabolite biomarkers associated with the active state of TB.
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Growth, thermal properties and laser operation of Nd:Ca3La2(BO3)4: a new disordered laser crystal.
Opt Express
PUBLISHED: 03-14-2013
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A novel disordered laser crystal Nd:Ca(3)La(2)(BO(3))(4) is characterized including its crystal growth, structure, thermal properties, inhomogeneously broadened spectra, and laser performance, which result that this crystal should be a promising gain material for the high-power ultrashort pulsed neodymium laser. The complete set of anisotropic thermal properties were systematically studied for the first time. It has been found that thermal contraction happens in the c direction and all the thermal conductivities increase with temperature, indicating a glass-like behavior. Polarized absorption and fluorescence spectra of Nd:Ca(3)La(2)(BO(3))(4) crystal were measured at 298.15 K and 77.3 K, respectively. The results show that both the absorption and the emission spectra of Nd(3+) have been inhomogeneously broadened, and thus it is very promising to be used in laser systems to produce femtosecond pulses. CW laser operations at 1.06 ?m along the three crystallographic directions has been demonstrated for the first time. A maximum power of 1.08 W with an optical conversion efficiency of 10.6% and slope efficiency of 12.4% was achieved in the a-cut sample.
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Functional characterization of two alternatively spliced transcripts of tomato ABSCISIC ACID INSENSITIVE3 (ABI3) gene.
Plant Mol. Biol.
PUBLISHED: 03-10-2013
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Alternative splicing can produce transcripts that encode proteins with altered functions. The transcripts of the ABSCISIC ACID INSENSITIVE3 (ABI3)/VIVIPAROUS1 (VP1) gene, which is an important component in abscisic acid (ABA) signaling, are subjected to alternative splicing in both monocotyledons and dicotyledons. We identified two alternatively spliced tomato (Solanum lycopersicum) SlABI3 transcripts, SlABI3-F and SlABI3-T, which encode the nucleus-localized full-length and truncated proteins, respectively. The tissue-specific accumulation of SlABI3-F and SlABI3-T was determined, particularly in seeds at different developmental stages and in response to phytohormonal and abiotic stress. Ectopic over-expression of SlABI3-F and SlABI3-T resulted in the induction of seed-specific genes SlSOM, SlEM1 and SlEM6 in vegetative tissues. However, over-expression of SlABI3-F, but not SlABI3-T, activated expression of the downstream gene SlABI5 and conferred hypersensitivity to exogenous ABA during seed germination and primary root growth. In addition, the SlABI3-F protein interacted with SlABI5 much stronger than SlABI3-T did in the yeast two-hybrid assay. These results suggest that SlABI3-F and SlABI3-T have similar and distinct functionality in the ABA signaling, dependent on which tissue/organ they accumulate in.
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Bactericidal effects of hematoporphyrin monomethyl ether-mediated photosensitization against pathogenic communities from supragingival plaque.
Appl. Microbiol. Biotechnol.
PUBLISHED: 03-01-2013
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Photodynamic antimicrobial chemotherapy (PACT) is proposed as a potential candidate to inactivate pathogens in localized infections due to the rapid evolution of bacterial resistance. The treatment modality utilizes nontoxic agents called photosensitizers and harmless visible light to generate reactive oxygen species which result in microbial cells killing. Hematoporphyrin monomethyl ether (HMME) as a novel and affordable photosensitizer has been used in treating various clinical diseases for years, but few applications in infection. In this report, we studied the bactericidal effects of the HMME-mediated photodynamic reaction on the pathogenic microbes in supragingival plaque which can lead to many oral infectious diseases such as caries, gingivitis, and so on. Our findings demonstrated that HMME promoted an effective action in bacterial reduction with the application of laser energy. Moreover, the antimicrobial activities were dramatically enhanced as the HMME concentration and exposure time were increased, but reached a plateau when matched the appropriate agent concentration and illumination. It was found that the survival fraction of microorganisms is exponentially dependent on the product of HMME concentration and irradiation time. These promising results suggest the HMME may be an excellently cost-effective photosensitizing agent for mediating PACT in the treatment of supragingival plaque-related diseases. An optimized HMME concentration and irradiation time has been found to achieve the best results under our experimental conditions. The high HMME concentration matching short curative time, or vice versa, can achieve the similar therapeutic effect, which may provide more flexible treatment plans according to specific conditions.
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Effects of 5-aminolevulinic acid-mediated sonodynamic therapy on macrophages.
Int J Nanomedicine
PUBLISHED: 02-13-2013
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Inflammatory cells exhibit an elevated level of protoporphyrin IX (PpIX) after the administration of 5-aminolevulinic acid (ALA). Here, we investigate the sonodynamic effects of ALA-derived PpIX (ALA-PpIX) on macrophages, which are the pivotal inflammatory cells in atherosclerosis.
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Spatio-spectral filters for low-density surface electromyographic signal classification.
Med Biol Eng Comput
PUBLISHED: 02-06-2013
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In this paper, we proposed to utilize a novel spatio-spectral filter, common spatio-spectral pattern (CSSP), to improve the classification accuracy in identifying intended motions based on low-density surface electromyography (EMG). Five able-bodied subjects and a transradial amputee participated in an experiment of eight-task wrist and hand motion recognition. Low-density (six channels) surface EMG signals were collected on forearms. Since surface EMG signals are contaminated by large amount of noises from various sources, the performance of the conventional time-domain feature extraction method is limited. The CSSP method is a classification-oriented optimal spatio-spectral filter, which is capable of separating discriminative information from noise and, thus, leads to better classification accuracy. The substantially improved classification accuracy of the CSSP method over the time-domain and other methods is observed in all five able-bodied subjects and verified via the cross-validation. The CSSP method can also achieve better classification accuracy in the amputee, which shows its potential use for functional prosthetic control.
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What is Visualize?

JoVE Visualize is a tool created to match the last 5 years of PubMed publications to methods in JoVE's video library.

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We use abstracts found on PubMed and match them to JoVE videos to create a list of 10 to 30 related methods videos.

Video X seems to be unrelated to Abstract Y...

In developing our video relationships, we compare around 5 million PubMed articles to our library of over 4,500 methods videos. In some cases the language used in the PubMed abstracts makes matching that content to a JoVE video difficult. In other cases, there happens not to be any content in our video library that is relevant to the topic of a given abstract. In these cases, our algorithms are trying their best to display videos with relevant content, which can sometimes result in matched videos with only a slight relation.