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Find video protocols related to scientific articles indexed in Pubmed.
Ocular Pharmacokinetics of Naringenin Eye Drops Following Topical Administration to Rabbits.
J Ocul Pharmacol Ther
PUBLISHED: 09-18-2014
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Abstract Purpose: To investigate the ocular pharmacokinetics of 1% naringenin eye drops following topical administration to rabbits. Methods: One drop (50??L) of 1% naringenin eye drops was instilled into both eyes of each rabbit. The animals were sacrificed at predetermined intervals after dosing, and ocular tissues and plasma were then collected. Concentrations of naringenin were analyzed using specific electrospray ionization liquid chromatography-tandem mass spectrometry method, which is proved to be sensitive, specific, precise, and suitable for determination of naringenin in ocular tissues and plasma of rabbits. Results: Ocular exposure to naringenin, based on AUC(0-t), was highest in cornea, followed by aqueous humor, retina, and vitreous body. The Cmax of naringenin in cornea, aqueous humor, vitreous body, and retina were 67945.30±4109.34?ng/g, 1325.69±239.34, 160.52±38.78?ng/mL, and 1927.08±660.77?ng/g at 0.083, 0.75, 0.083, and 0.083?h after topical administration, respectively. The half-lives for these tissues were 9.37, 0.65, 1.17, and 4.62?h, respectively. There was no significant difference between free naringenin and total naringenin in plasma based on Cmax and Tmax. Cmax of total naringenin in plasma at 0.083?h was 35.12±0.54?ng/mL. Conclusions: Measurable concentrations of naringenin were achieved in ocular tissues after topical application in rabbits. Topical instillation of naringenin may be an effective approach in the treatment of posterior section diseases.
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Profiling the T-cell receptor repertoire of patient with pleural tuberculosis by high-throughput sequencing.
Immunol. Lett.
PUBLISHED: 08-27-2014
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Pleural tuberculosis (PLTB), a major cause of morbidity and mortality, is the most common extrapulmonary manifestation of active Mycobacterium tuberculosis (Mtb) in developing countries. Gamma delta T-cell receptor (TCR) repertoire of peripheral blood mononuclear cells (PBMCs) and pleural effusion mononuclear cells (PEMCs) and beta TCR repertoire from peripheral blood mononuclear cells (PBMCs) have been reported. However, a detailed different characteristic of beta TCR repertoire of mononuclear cells isolated from peripheral blood and pleural fluid in the immune response to Mtb infection should be further revealed. The TCR ?-chain (TRB) from PBMCs and PEMCs from an untreated pleural tuberculosis patient was sequenced by the Illumina sequencing platform. A total of 96,758 and 124,130 unique complementarity-determining region 3 (CDR3) sequences were identified at the nucleotide level, encoding 69,488 and 99,095 peptide sequences, respectively. TCR profiling showed that TRBV20-1 family and TRBV20-1/TRBJ1-5 gene combination had a dominant expression in PEMCs, but not in PBMCs. Expansive expression of common CDR3 clonotypes was observed in PEMCs. CDR3 spectratyping analysis showed that few TRBV families had a significantly skewed pattern, with one peak or a few prominent peaks in the PBMCs. By contrast, some TRBV families showed oligoclonal or clonal expansion in the PEMCs. Here, we firstly profiled the TRB repertoire differences of PBMCs and PEMCs from one PLTB patient using high-throughput sequencing. And this study may provide new insight for the detailed and efficient study of TCR repertoire of PEMCs in the future.
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Simultaneous breast reconstruction and treatment of breast cancer-related upper arm lymphedema with lymphatic lower abdominal flap.
Ann Plast Surg
PUBLISHED: 08-14-2014
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This study was designed to introduce the key points about the transplantation of lower abdominal flap with vascularized lymph node and to evaluate the effect of breast restoration, breast reconstruction, and lymphatic transplantation to treat upper limb lymphedema after breast cancer surgery.
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Jam1a-Jam2a interactions regulate haematopoietic stem cell fate through Notch signalling.
Nature
PUBLISHED: 08-13-2014
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Notch signalling plays a key role in the generation of haematopoietic stem cells (HSCs) during vertebrate development and requires intimate contact between signal-emitting and signal-receiving cells, although little is known regarding when, where and how these intercellular events occur. We previously reported that the somitic Notch ligands, Dlc and Dld, are essential for HSC specification. It has remained unclear, however, how these somitic requirements are connected to the later emergence of HSCs from the dorsal aorta. Here we show in zebrafish that Notch signalling establishes HSC fate as their shared vascular precursors migrate across the ventral face of the somite and that junctional adhesion molecules (JAMs) mediate this required Notch signal transduction. HSC precursors express jam1a (also known as f11r) and migrate axially across the ventral somite, where Jam2a and the Notch ligands Dlc and Dld are expressed. Despite no alteration in the expression of Notch ligand or receptor genes, loss of function of jam1a led to loss of Notch signalling and loss of HSCs. Enforced activation of Notch in shared vascular precursors rescued HSCs in jam1a or jam2a deficient embryos. Together, these results indicate that Jam1a-Jam2a interactions facilitate the transduction of requisite Notch signals from the somite to the precursors of HSCs, and that these events occur well before formation of the dorsal aorta.
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Application of iron magnetic nanoparticles in protein immobilization.
Molecules
PUBLISHED: 05-23-2014
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Due to their properties such as superparamagnetism, high surface area, large surface-to-volume ratio, easy separation under external magnetic fields, iron magnetic nanoparticles have attracted much attention in the past few decades. Various modification methods have been developed to produce biocompatible magnetic nanoparticles for protein immobilization. This review provides an updated and integrated focus on the fabrication and characterization of suitable magnetic iron nanoparticle-based nano-active materials for protein immobilization.
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Bacterial multidrug efflux pumps: Mechanisms, physiology and pharmacological exploitations.
Biochem. Biophys. Res. Commun.
PUBLISHED: 05-02-2014
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Multidrug resistance (MDR) refers to the capability of bacterial pathogens to withstand lethal doses of structurally diverse drugs which are capable of eradicating non-resistant strains. MDR has been identified as a major threat to the public health of human being by the World Health Organization (WHO). Among the four general mechanisms that cause antibiotic resistance including target alteration, drug inactivation, decreased permeability and increased efflux, drug extrusion by the multidrug efflux pumps serves as an important mechanism of MDR. Efflux pumps not only can expel a broad range of antibiotics owing to their poly-substrate specificity, but also drive the acquisition of additional resistance mechanisms by lowering intracellular antibiotic concentration and promoting mutation accumulation. Over-expression of multidrug efflux pumps have been increasingly found to be associated with clinically relevant drug resistance. On the other hand, accumulating evidence has suggested that efflux pumps also have physiological functions in bacteria and their expression is subject tight regulation in response to various of environmental and physiological signals. A comprehensive understanding of the mechanisms of drug extrusion, and regulation and physiological functions of efflux pumps is essential for the development of anti-resistance interventions. In this review, we summarize the development of these research areas in the recent decades and present the pharmacological exploitation of efflux pump inhibitors as a promising anti-drug resistance intervention.
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Protective effect of truncated Na+/K+-ATPase ? on ischemia/reperfusion-induced renal injury in rats.
Exp. Biol. Med. (Maywood)
PUBLISHED: 04-15-2014
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Renal ischemia/reperfusion(I/R) is an important injury part of ischemic acute renal failure, and it is also the main factor that affects the early functional recovery and the long-term survival of transplanted kidney in renal transplantation. In this study, we cloned and expressed truncated Na+/K+-ATPase ?(tNKA?) and demonstrated that tNKA? could activate NKA ? subunit and induce protective effect on human kidney-2(HK-2) cells via PKC? signal pathway. The half maximum effective concentrations (EC50) of tNKA? were 0.24?µM. Furthermore, the application of EAVSLKPT (PKC? inhibitor) could abolish the protective effect of tNKA? in HK-2 cells subjected to ischemia/reperfusion. To identify the protective effect of tNKA? against the I/R injury in the kidney, Sprague-Dawley rats were treated with tNKA? (75?mg/kg) for 2?h before ischemia. The tNKA?-treated group demonstrated a significant improvement in renal function with a lower serum creatinine and blood urea nitrogen (BUN) levels on postoperative days 1-6. Renal sections obtained from rats of the I/R group showed serious renal injury which included degeneration of tubular structure, tubular dilation, swelling and necrosis, luminal congestion, and muddy brown casts formed by sloughing of severely damaged tubular epithelial cells. However, sections of rats that were administered with tNKA? 2?h before reperfusion showed marked reduction of the histological features of renal injury compared with kidneys that were subjected to I/R only. In conclusion, the protective effects of tNKA? against renal I/R injury have been evaluated for the first time, and these protective effects may occur via stimulation of PKC? pathways.
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Co-expression of EtMic2 protein and chicken interleukin-18 for DNA vaccine against chicken coccidiosis.
Res. Vet. Sci.
PUBLISHED: 03-29-2014
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In the present study, a naked EtMIC2 DNA vaccine, a ChIL-18 expression vector and a EtMIC2 and ChIL-18 co-expression DNA vaccine were constructed and their protective efficacies against homologous challenge were compared and evaluated by examining the body weight gain, oocyst shedding, cecal lesion, ACI as well as specific anti-EtMic2 antibody level, the proliferation ability and percentages of CD4+ and CD8+ of splenocytes. The results showed the naked EtMIC2 DNA vaccine could increase the weight gain and decrease the oocyst shedding, but could not alleviate the cecal lesion of immunized chickens compared to unimmunized chickens. Chickens immunized with the co-expression vector pVAX1-MIC2-IL-18 exhibited much improved immune protection against challenge compared to chickens immunized with naked EtMIC2 DNA vaccine, or with naked EtMIC2 DNA vaccine and ChIL-18 expression vector applied separately. These results suggest that the co-expression of ChIL-18 with EtMic2 together could significantly improve the immune protection of the EtMic2 protein.
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Protective effects of N-acetylcysteine on cisplatin-induced oxidative stress and DNA damage in HepG2 cells.
Exp Ther Med
PUBLISHED: 03-18-2014
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Hepatocyte injury is a common pathological effect of cisplatin (CDDP) in various solid tumor therapies. Thus, strategies for minimizing CDDP toxicity are of great clinical interest. N-acetylcysteine (NAC), a known antioxidant, is often used as an antidote for acetaminophen overdose in the clinic due to its ability to increase the levels of glutathione (GSH). In the present study, the aim was to investigate the protective effects of NAC against CDDP-induced apoptosis in human-derived HepG2 cells. The results showed that upon exposure of the cells to CDDP, oxidative stress was significantly induced. DNA damage caused by CDDP was associated with cell apoptosis. NAC pre-treatment significantly reduced the malondialdehyde (MDA) levels and ameliorated the GSH modulation induced by CDDP. NAC also protected against DNA damage and cell apoptosis. These data suggest the protective role of NAC against hepatocyte apoptosis induced by CDDP was achieved through the inhibition of DNA damage and alterations of the redox status in human derived HepG2 cells. These results indicate that NAC administration may protect against CDDP-induced damage.
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Design, synthesis and properties of artificial nucleic acids from (R)-4-amino-butane-1,3-diol.
Org. Biomol. Chem.
PUBLISHED: 02-27-2014
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A new artificial nucleic acid analogue, (R)-Am-BuNA, was developed with a simplified acyclic (R)-4-amino-butane-1,3-diol phosphodiester backbone. Phosphoramidite monomers of (R)-Am-BuNA were incorporated into DNA oligonucleotides (ODNs) and G-quadruplexes. Their thermal stability, conformation change and biological stability were further investigated using UV-melting, circular dichroism (CD) and gel electrophoresis. The results suggested that thermal stability of the duplexes of (R)-Am-BuNA modified ODNs and their complementary ODN is highly dependent on the substitution position. Substitution of thymidine at the 7th position in a thrombin-binding DNA aptamer (TBA) results in a slight increase in Tm with no effect on quadruplex conformation on the CD spectrum in comparison to that of the natural G-quadruplex. Further enzymatic experiments with fetal bovine serum (FBS) and snake venom phosphodiesterase (SVPDE) indicated that only single replacement of a (R)-Am-BuNA modified nucleobase greatly inhibited oligonucleotide degradation, which shows their promising applications as capping nucleotides in nucleic acid drugs.
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Simultaneous determination of osthole, bergapten and isopimpinellin in rat plasma and tissues by liquid chromatography-tandem mass spectrometry.
J. Chromatogr. B Analyt. Technol. Biomed. Life Sci.
PUBLISHED: 02-26-2014
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A highly selective and sensitive method for simultaneous quantitation of osthole, bergapten and isopimpinellin in rat plasma and tissues was developed by liquid chromatography-tandem quadrupole mass spectrometry (LC-MS/MS). After liquid-liquid extraction of samples with methyl tert-butyl ether, the analytes and dextrorphan (internal standard, IS) were separated by a Hypersil GOLD AQ C18 column with gradient elution of acetonitrile and water containing 0.5‰ formic acid. Three determinands were detected using an electrospray ionization (ESI) tandem mass spectrometry in the multiple reaction monitoring (MRM) modes with positive electrospray ionization. Calibration curves were recovered over the concentration ranges of 1-200 ng/ml, 1-500 ng/ml, 0.25-200 ng/ml for osthole, bergapten and isopimpinellin in plasma; 1-100 ng/ml, 1-500 ng/ml, 0.5-100 ng/ml for osthole, bergapten and isopimpinellin in tissues, respectively. The intra-day precision (R.S.D.) was within 13.90% and the intra-day accuracy (R.E.) was within -6.27 to 6.84% in all biological matrixes. The inter-day precision (R.S.D.) was less than 13.66% and the inter-day accuracy (R.E.) was within -10.64 to 13.04%. Then the method was successfully applied to investigate plasma pharmacokinetic study and tissue distribution of osthole, bergapten and isopimpinellin in rats after oral administration of Fructus Cnidii extraction, especially for testis/uterus tissue distribution. The results demonstrated that osthole, bergapten and isopimpinellin were absorbed and eliminated rapidly with wide distributions in rats. Distribution data of these three bioactive components in testis/uterus tissues could offer useful information for the further preclinical and clinical studies of Fructus Cnidii in the treatment of genital system disease.
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CD4 T cells require ICOS-mediated PI3K signaling to increase T-Bet expression in the setting of anti-CTLA-4 therapy.
Cancer Immunol Res
PUBLISHED: 01-24-2014
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The transcription factor T-bet controls the Th1 genetic program in T cells for effective antitumor responses. Anti-CTLA-4 immunotherapy elicits dramatic antitumor responses in mice and in human patients; however, factors that regulate T-bet expression during an antitumor response mediated by anti-CTLA-4 remain to be elucidated. We were the first to report that treatment with anti-CTLA-4 led to an increase in the frequency of T cells expressing inducible costimulator (ICOS). In both treated patients and mice, our data revealed that CD4(+)ICOS(hi) T cells can act as effector T cells, which produce the Th1 cytokine IFN-?. We also showed in a small retrospective analysis that an increased frequency of CD4(+)ICOS(hi) T cells correlated with better clinical outcome and the absence of ICOS or its ligand (ICOSL) in mouse models led to impaired tumor rejection. Here, we show that CD4(+)ICOS(hi) T cells from anti-CTLA-4-treated patients had an increase in signaling via the phospoinositide-3-kinase (PI3K) pathway and an increase in expression of T-bet. An ICOS-specific siRNA transfected into human T cells led to diminished PI3K signaling and T-bet expression. Therefore, we hypothesized that ICOS, and specifically ICOS-mediated PI3K signaling, was required for T-bet expression. We conducted studies in ICOS-deficient and ICOS-YF mice, which have a single amino acid change that abrogates PI3K signaling by ICOS. We found that ICOS-mediated PI3K signaling is required for T-bet expression during an antitumor response elicited by anti-CTLA-4 therapy. Our data provide new insight into the regulation of T-bet expression and suggest that ICOS can be targeted to improve Th1 antitumor responses.
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Cholesterol-based cationic lipids for gene delivery: contribution of molecular structure factors to physico-chemical and biological properties.
Colloids Surf B Biointerfaces
PUBLISHED: 01-21-2014
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In this work, we prepared a series of cholesterol-based cationic (Cho-cat) lipids bearing cholesterol hydrophobe, natural amino acid headgroups (lysine/histidine) and linkage (carbonate ester/ether) bonds. In which, the natural amino acid headgroups made dominant contribution to their physico-chemical and biological properties. Among the lipids, the l-lysine headgroup bearing lipids (Cho-es/et-Lys) showed higher pDNA binding affinity and were able to form larger sized and higher surface charged lipoplexes than that of l-histidine headgroup bearing lipids (Cho-es/et-His), they also demonstrated higher transfection efficacy and higher membrane disruption capacities than that of their l-histidine headgroup bearing counterparts. However, compared to the contributions of the headgroups, the (carbonate ester/ether) linkage bonds showed much less affects. Besides, it could be noted that, Cho-es/et-Lys lipids exhibited very high luciferase gene transfection efficiency that almost reached the transfection level of "gold standard" bPEI-25k, made them potential transfection reagents for practical application. Moreover, the results facilitated the understanding for the structure-activity relationship of the cholesterol-based cationic lipids, and also paved a simple and efficient way for achieving high transfection efficiency by modification of suitable headgroups on lipid gene carriers.
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Molecular identification of clinical "difficult-to-identify" microbes from sequencing 16S ribosomal DNA and internal transcribed spacer 2.
Ann. Clin. Microbiol. Antimicrob.
PUBLISHED: 01-03-2014
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Clinical microbiology laboratories have to accurately identify clinical microbes. However, some isolates are difficult to identify by the automated biochemical text platforms, which are called "difficult-to-identify" microbes in this study. Therefore, the ability of 16S ribosomal DNA (16S rDNA) and internal transcribed spacer 2 (ITS2) sequencing to identify these "difficult-to-identify" bacteria and fungi was assessed in this study.
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A prospective study of breast dynamic morphological changes after dual-plane augmentation mammaplasty with 3D scanning technique.
PLoS ONE
PUBLISHED: 01-01-2014
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The dual-plane technique has been widely used in augmentation mammaplasty procedures. However, there are some concerns about aesthetic contour maintenance for long time after muscle releasing. This study aims to track and analyze breast dynamic morphological changes after dual-plane breast augmentation with three-dimensional (3D) scanning technique.
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Optical-assembly periodic structure of ferrofluids in a liquid core/metal cladding optical waveguide.
Appl Opt
PUBLISHED: 11-13-2013
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We present a novel and simple mechanism for the fabrication of periodic microstructure based on a ferrofluids core/metal cladding optical waveguide chip. The ultrahigh-order modes excited in the millimeter scale guiding layer lead to the ordered particle aggregates in ferrofluids without applying a magnetic field. Since the absorption of photons by the extremely dilute ferrofluids is extremely small and the Soret effect is not noticeable, a tentative explanation in terms of the optical trapping effect is proposed. Furthermore, this scheme exhibits all-optically tunable reflectivity and lateral Goos-Hänchen shift, which potentially may be for practical use in novel optical devices.
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Caged nucleotides/nucleosides and their photochemical biology.
Org. Biomol. Chem.
PUBLISHED: 10-17-2013
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Nucleotides and nucleosides are not only key units of DNA/RNA that store genetic information, but are also the regulators of many biological events of our lives. By caging the key functional groups or key residues of nucleotides with photosensitive moieties, it will be possible to trigger biological events of target nucleotides with spatiotemporal resolution and amplitude upon light activation or photomodulate polymerase reactions with the caged nucleotide analogues for next-generation sequencing (NGS) and bioorthogonal labeling. This review highlights three different caging strategies for nucleotides and demonstrates the photochemical biology of these caged nucleotides.
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Probe alignment and design issues of microelectromechanical system based optical coherence tomography endoscopic imaging.
Appl Opt
PUBLISHED: 10-03-2013
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Endoscopic optical coherence tomography (OCT) imaging has been demonstrated using microelectromechanical system (MEMS) technology by several research groups. The focus of this work is to study how the OCT imaging performance is affected by the radius of curvature of MEMS mirrors as well as the optical alignment accuracy inside small imaging probes. The goal of this study is to provide guidance for assembly tolerance and design optimization of OCT endoscopic probes. Gaussian beam propagation is used for theoretical analysis which is confirmed by optical simulation and verified experimentally with a time-domain OCT system as well. It has been found that the OCT imaging is very sensitive to the distance from the fiber end to the gradient-index (GRIN) lens, which needs to be controlled within 0.1 mm to achieve working distance (WD) longer than 3.5 mm and lateral resolution around 25 ?m. The impact on image quality of the MEMS mirror is negligible if the radius of curvature of the mirror surface is greater than 200 mm. In addition, we studied the astigmatism introduced by cylindrical plastic tubing; the maximum astigmatism ratio is 1.1 when the WD is around 2.5 mm.
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The establishment of a duplex real-time PCR assay for rapid and simultaneous detection of blaNDM and blaKPC genes in bacteria.
Ann. Clin. Microbiol. Antimicrob.
PUBLISHED: 09-05-2013
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The latest threat of multidrug-resistant Gram-negative bacteria corresponds to the emergence of carbapenemase New Delhi metallo-beta-lactamase (NDM) and Klebsiella pneumoniae carbapenemase (KPC) producers. Rapid molecular detection is essential to limit their spread. In this study, a duplex real-time polymerase chain reaction (PCR) that was specific for the detection of blaNDM and blaKPC with the same limit of detection of ten plasmid copies was developed. The assay was linear over eight log dilutions for blaNDM (R2 = 0.971; slope, -3.273) and blaKPC (R2 = 0.992; slope, -2.997) with efficiencies of 102% and 115%, respectively. The assay was validated with 157 clinical isolates and showed 100% concordance with conventional PCR. The excellent performance of the duplex PCR assay makes it a powerful tool for surveillance of the carbapenemases NDM and KPC.
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Click synthesized sterol-based cationic lipids as gene carriers, and the effect of skeletons and headgroups on gene delivery.
Bioorg. Med. Chem.
PUBLISHED: 06-18-2013
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In this work, we have successfully prepared a series of new sterol-based cationic lipids (1-4) via an efficient Click chemistry approach. The pDNA binding affinity of these lipids was examined by EB displacement and agarose-gel retardant assay. The average particle sizes and surface charges of the sterol-based cationic lipids/pDNA lipoplexes were analyzed by dynamic laser light scattering instrument (DLS), and the morphologies of the lipoplexes were observed by atomic force microscopy (AFM). The cytotoxicity of the lipids were examined by MTT and LDH assay, and the gene transfection efficiencies of these lipid carriers were investigated by luciferase gene transfection assay in various cell lines. In addition, the intracellular uptake and trafficking/localization behavior of the Cy3-DNA loaded lipoplexes were preliminarily studied by fluorescence microscopy. The results demonstrated that the pDNA loading capacity, lipoplex particle size, zeta potential and morphology of the sterol lipids/pDNA lipoplexes depended largely on the molecular structure factors including sterol-skeletons and headgroups. Furthermore, the sterol-based lipids showed quite different cytotoxicity and gene transfection efficacy in A549 and HeLa cells. Interestingly, it was found that the cholesterol-bearing lipids 1 and 2 showed 7-10(4) times higher transfection capability than their lithocholate-bearing counterparts 3 and 4 in A549 and HeLa cell lines, suggested that the gene transfection capacity strongly relied on the structure of sterol skeletons. Moreover, the study on the structure-activity relationships of these sterol-based cationic lipid gene carriers provided a possible approach for developing low cytotoxic and high efficient lipid gene carriers by selecting suitable sterol hydrophobes and cationic headgroups.
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High-sensitivity temperature sensor using the ultrahigh order mode-enhanced Goos-Hänchen effect.
Opt Express
PUBLISHED: 06-06-2013
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A high-sensitivity temperature sensor based on the enhanced Goos-Hänchen effect in a symmetrical metal-cladding waveguide is theoretically proposed and experimentally demonstrated. Owing to the high sensitivity of the ultrahigh-order modes, any minute variation of the refractive index and thickness in the guiding layer induced by the thermo-optic and thermal expansion effects will easily give rise to a dramatic change in the position of the reflected light. In our experiment, a series of Goos-Hänchen shifts are measured at temperatures varying from 50.0 °C to 51.2 °C with a step of 0.2 °C. The sensor exhibits a good linearity and a high resolution of approximately 5×10(-3) °C. Moreover, there is no need to employ any complicated optical equipment and servo techniques, since our transduction scheme is irrelevant to the light source fluctuation.
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Endoplasmic reticulum localization of poly(?-aminohexyl methacrylamide)s conjugated with (L-)-arginines in plasmid DNA delivery.
Biomaterials
PUBLISHED: 06-05-2013
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In this work, we first synthesized a ?-amino group Boc-protected poly(?-aminohexyl methacrylamide) PAHMAA-Boc precursor via controlled reversible addition-fragmentation chain transfer (RAFT) polymerization of the Boc-AHMAA monomer in THF solution, and poly(?-aminohexyl methacrylamide) (PAHMAA) was then prepared via Boc deprotection, and was further conjugated with (L-)-arginines at the ?-amino group sites to give a series of new (L-)-arginine conjugated PAHMAA-R7, PAHMAA-R16 and PAHMAA-R22. Employing these PAHMAA and PAHMAA-Rs as functional gene vectors, their plasmid DNA binding affinities were examined by agarose gel retardant assay. By means of dynamic light scattering (DLS), mean particle sizes and zeta potentials of the polyplexes were analyzed. Moreover, cytotoxicities of the PAHMAA and PAHMAA-Rs were evaluated by MTT and lactate dehydrogenase (LDH) release assays with COS-7 cells, and luciferase and EGFP gene transfection efficacies by these vectors were assayed in COS-7 and HeLa cells. Furthermore, intracellular uptake of the vector/Cy3-labeled pDNA polyplexes was studied with a flow cytometer (FACS), and the most efficient PAHMAA-R16 vector was employed to investigate the endocytic gateways with various inhibitors. In addition, colocalization of the Cy3-labeled pDNA and Oregon Green labeled PAHMAA-R16 vector in the intracellular organelles of COS-7 cells was visualized on a fluorescence microscopy. As a result, it was revealed that the PAHMAA-R vectors showed lower cytotoxicities and transfection efficacies significantly higher than those of the PAHMAA, strongly depending on their percentage of arginine conjugation, and that the results of endocytic inhabitation and fluorescence colocalization in endoplasmic reticulum may suggest a caveolae-mediated efficient intracellular trafficking route for the synthesized PAHMAA-R vectors.
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Does Respiration Influence Breast Volumetric Change Measurement with the Three-Dimensional Scanning Technique?
Aesthetic Plast Surg
PUBLISHED: 06-03-2013
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Measurement of volumetric change after aesthetic and reconstructive breast surgery is of great significance to plastic surgeons. This study aimed to investigate the influence of respiration on measurement of breast volumetric change via a three-dimensional (3D) scanning technique.
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Quantitative analysis of tenuifolin concentrations in rat plasma and tissue using LC?MS/MS: Application to pharmacokinetic and tissue distribution study.
J Pharm Biomed Anal
PUBLISHED: 04-27-2013
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A sensitive, reliable and accurate reversed-phased liquid chromatography with tandem mass spectrometry (LC?MS/MS) in negative ion mode was developed and validated for the quantification of tenuifolin in rat plasma and tissue. A single step protein precipitation by methanol was used to prepare plasma and tissue homogenate samples. Tenuifolin and polydatin (internal standard, IS) were separated by HPLC using a C18 column and an isocratic mobile phase consisted of acetonitrile and water containing 0.05% formic acid (42:58, v/v) running at a flow rate of 0.2 ml/min for 6 min. Detection and quantification were performed using a mass spectrometer by the multiple reaction monitoring (MRM) in negative electrospray ionization mode. The transition monitored were m/z [M?H](?) 679.4 ? 455.4 for tenuifolin and m/z [M?H](?) 389.0 ? 227.2 for IS, respectively. Calibration curves were recovered over a concentration range of 0.5?1000 ng/ml for plasma, heart, liver, lung and kidney, 0.5?200 ng/ml for spleen, and 0.5?50 ng/ml for brain, respectively. The lower limit of quantification was 0.5 ng/ml for plasma and tissue homogenates. The inter-day precision (R.S.D.) was less than 12.9% and intra-day precision R.S.D. was less than 13.4%, while the inter-day accuracy (R.E.) was ranged from ?7.20 to 6.87% and intra-day accuracy (R.E.) was ranged from ?6.20 to 8.04% in plasma and tissue homogenates. This method was successfully applied to the pharmacokinetic and tissue distribution study of pure tenuifolin in rat. The pharmacokinetic study indicated that poor absorption into systemic circulation was observed after rat was administered orally tenuifolin, and the absolute bioavailability was low (0.83 ± 0.28%). The results of tissue distribution showed the higher tenuifolin concentrations were found in liver, kidney and heart, and the small amount of drug was distributed quickly into the brain tissue at 5 min after the intravenous injection of tenuifolin. The fact that tenuifolin could cross the blood?brain barrier provided the material basis for pharmacological action of the tenuifolin in the treatment of memory loss.
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Class 1 integrons in urinary isolates of extended-spectrum ?-lactamase-producing Escherichia coli and Klebsiella pneumoniae in Southern China during the past five years.
Microb. Drug Resist.
PUBLISHED: 04-10-2013
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We analyzed extended-spectrum ?-lactamase (ESBL)-producing Escherichia coli (226) and Klebsiella pneumoniae (53) collected from urine specimens during 2005-2009 for the presence of ESBL genes, class 1 integrons, and characterization of gene cassettes. TEM and CTX-M ?-lactamase genes were the most prevalent. One hundred and forty-four E. coli and 35 K. pneumoniae were positive for the class 1 integrase gene; among them, 99 E. coli and 14 K. pneumoniae detected gene cassettes. Gene cassette regions were identified by restriction fragment length polymorphism and DNA sequencing analysis. Eleven distinct gene cassette arrays were found in E. coli isolates, and seven distinct gene cassette arrays were found in K. pneumoniae isolates. The cassette array aacA4-catB8-aadA1 was first found in E. coli and dfrA1-orfC was first reported in K. pneumoniae. Most of the gene cassettes found in this class 1 integrons were for aminoglycoside resistance. Enterobacterial repetitive intergenic consensus-polymerase chain reaction fingerprint patterns revealed the isolates carrying gene cassettes were genetically unrelated. In conclusion, we studied the class 1 integrons among urinary isolates of ESBL-producing E. coli and K. pneumoniae in Southern China during the past 5 years and found that class 1 integrons were widely disseminated and played a major role in antibiotic resistance.
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Foxc1 controls the growth of the murine frontal bone rudiment by direct regulation of a Bmp response threshold of Msx2.
Development
PUBLISHED: 01-23-2013
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The mammalian skull vault consists of several intricately patterned bones that grow in close coordination. The growth of these bones depends on the precise regulation of the migration and differentiation of osteogenic cells from undifferentiated precursor cells located above the eye. Here, we demonstrate a role for Foxc1 in modulating the influence of Bmp signaling on the expression of Msx2 and the specification of these cells. Inactivation of Foxc1 results in a dramatic reduction in skull vault growth and causes an expansion of Msx2 expression and Bmp signaling into the area occupied by undifferentiated precursor cells. Foxc1 interacts directly with a Bmp responsive element in an enhancer upstream of Msx2, and acts to reduce the occupancy of P-Smad1/5/8. We propose that Foxc1 sets a threshold for the Bmp-dependent activation of Msx2, thus controlling the differentiation of osteogenic precursor cells and the rate and pattern of calvarial bone development.
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Paeonol suppresses lipopolysaccharide-induced inflammatory cytokines in macrophage cells and protects mice from lethal endotoxin shock.
Fundam Clin Pharmacol
PUBLISHED: 01-14-2013
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Paeonol (2-hydroxy-4-methoxyacetophenone) is the main phenolic compound of the radix of Paeonia suffruticosa which has been used as traditional Chinese medicine. In this study, we primarily investigated the anti-inflammatory effects and the underlying mechanisms of paeonol in RAW macrophage cells; and based on these effects, we assessed the protective effects of paeonol on lipopolysaccharide-induced endotoxemia in mice. The in vitro study showed that paeonol regulated the production of TNF-?, IL-1?, IL-6, and IL-10 via inactivation of I?B?, ERK1/2, JNK, and p38 MAPK. In mouse model of lipopolysaccharide-induced endotoxemia, pro- and anti-inflammatory cytokines are significantly regulated, and thus the survival rates of lipolysaccharide-challenged mice are improved by paeonol (150, 200, or 250 mg/kg). Therefore, paeonol has a beneficial activity against lipopolysaccharide-induced inflammation in RAW 264.7 cell and mouse models.
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Simultaneous determination of Eleutheroside B and Eleutheroside E in rat plasma by high performance liquid chromatography-electrospray ionization mass spectrometry and its application in a pharmacokinetic study.
J. Chromatogr. B Analyt. Technol. Biomed. Life Sci.
PUBLISHED: 01-14-2013
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Eleutheroside B and Eleutheroside E, two kinds of the major bioactive saponins of Eleutherococcus senticosus, play a pivotal role in biologic activity. In this study, a specific and sensitive high performance liquid chromatography-electrospray ionization-tandem mass spectrometry method (HPLC-MS/MS) was developed and validated for simultaneous determination of Eleutheroside B and Eleutheroside E in rat plasma. The analytes were extracted from rat plasma via a simple protein precipitation procedure with methanol and polygonin was used as internal standard. Chromatographic separation was achieved on a C18 column using a gradient elution program with acetonitrile and water containing 0.1% ammonium hydroxide solution as the mobile phase, with a flow rate of 0.2mL/min. The detection was performed on a triple-quadrupole tandem mass spectrometer by multiple reactions monitoring (MRM) mode in a negative ion mode via electrospray ionization (ESI). The transition monitored were m/z 371 [M-H](-)?209 for Eleutheroside B, m/z 741[M-H](-)?579 for Eleutheroside E and m/z 389[M-H](-)?277 for internal standard. Linear calibration curves were obtained in the concentration range of 1-2000ng/mL for both (Eleutheroside B and Eleutheroside E), with a lower limit of quantification of 1ng/mL. Extraction recovery was over 80% in plasma. The intra- and inter-day precision (RSD) values were below 12% and accuracy (RE) was -2.80 to 5.70% at three QC levels for both. The assay was successfully applied to study pharmacokinetics behavior in rats after oral and intravenous administration of the single substances (Eleutheroside B and Eleutheroside E). And further research was performed by comparing the difference in pharmacokinetic behavior between the single substances and an aqueous extract of E. senticosus after oral administration. Significant difference in pharmacokinetic characteristics between the single substances and an aqueous extract was found in rat, which would be beneficial for the pre-clinical research and clinical use of E. senticosus.
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Galanin participates in the functional regulation of the diabetic heart.
Life Sci.
PUBLISHED: 01-13-2013
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The diabetic heart is characterized by its impaired ability to utilize glucose. Therapeutic interventions focusing on reducing insulin resistance and enhancing glucose uptake may improve prevention and treatment of the diabetic heart. Recent studies provided some compelling clues that neuropeptide galanin is closely associated with insulin sensitivity in the heart. Galanin may directly affect glucose homeostasis and carbohydrate metabolism in cardiac and skeletal muscles as well as increase glucose transporter 4 (GLUT4) expression and translocation in insulin-sensitive cells to reduce insulin resistance. These findings suggest that endogenous galanin has a beneficial effect on the diabetic heart. This paper highlights the effect of galanin on regulating heart rate, blood pressure, insulin sensitivity and glucose homeostasis to protect the diabetic heart. Our findings, therefore, deepen our understanding of the pathology of the diabetic heart and help evaluate the therapeutic potential of galanin-receptor ligands for cardiomyopathy.
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Identification of human regulatory T cells in the setting of T-cell activation and anti-CTLA-4 immunotherapy on the basis of expression of latency-associated peptide.
Cancer Discov
PUBLISHED: 12-27-2011
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Effector and regulatory T cells (Treg) share multiple markers that make it difficult to discern differences in these populations in humans. The transcription factor FoxP3 has been shown to identify Tregs. However, the detection of FoxP3 requires cell permeabilization, thereby preventing isolation of viable Tregs. Subsequently, the extracellular marker CD127 was established for the identification of Tregs. However, these studies were not conducted in the setting of immunotherapy. Here, we conducted studies to analyze CD127 and FoxP3 expression on T cells before and after in vitro activation as well as in the setting of patients treated with antibodies directed against cytotoxic T-lymphocyte antigen-4 (CTLA-4). We show that latency-associated peptide (LAP), as opposed to CD127, was capable of identifying Tregs after in vitro activation as well as after treatment with anti-CTLA-4. Therefore, we propose that LAP should be used as a marker of Tregs for immune monitoring studies in patients treated with active immunotherapy such as anti-CTLA-4.
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A coordination complex system for generic, ultrafast, and sensitive multimode fluorescent staining of biomolecules.
Inorg Chem
PUBLISHED: 12-06-2011
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Gel electrophoresis staining methodologies documented thus far are largely utilized in a biomolecule context-dependent manner. We report herein the development of a generic, ultrafast, and sensitive multimode fluorescent system for the efficient identification of DNA, RNA, and proteins. Interaction between a positively charged, planar ligand-based coordination complex with partner biomolecule leads to aggregation-induced fluorescence quenching and allows for the image contrast generation within one minute. Alternatively, successive reactions of the biomolecule-loaded gel with cation and ligand, in either order of sequence, provide an equally effective staining efficacy. Image contrast reversal is accomplished through a facile washing or photobleaching procedure. The versatility in the applicable target species and signal generation modes provides a hint at the design of novel staining structures and potentially enables the high-throughput readout of biomolecules.
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Honeycomb-structured films by multifunctional amphiphilic biodegradable copolymers: surface morphology control and biomedical application as scaffolds for cell growth.
ACS Appl Mater Interfaces
PUBLISHED: 07-06-2011
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Recently, fabrication of functional porous polymer films with patterned surface structures at the scale from nanometer to micrometer has been attracting increasing interests in material science and nanobiotechnology. In this work, we present new preparation of two series of multifunctional amphiphilic copolymers and preparation of their microporous thin films on solid substrates. First, diblock dendritic poly(l-lysine)-b-poly(l-lactide)s and triblock dendritic poly(l-lysine)-b-poly(l-lactide)-b-dendritic poly(l-lysine)s (C1-C6) were synthesized through 4-dimethylaminopyridine (DMAP)-catalyzed living ring-opening polymerization of (l-)-lactide with (l-)-lysine dendron initiators, and their structures were characterized by nuclear magnetic resonance spectrometer (NMR), gel permeation chromatography (GPC) and matrix-assisted laser desorption/ionization Fourier-transformed mass spectra (MALDI-FTMS). Employing the breath-figure (BF) fabrication strategy, thin films of the synthesized amphiphiles (C1-C6) were drop-cast, and their surface topologies were examined by scanning electron microscopy (SEM) and atomic force microscopy (AFM), and the effects of new amphiphile structure and drop-casting parameters of amphiphile concentration, humidity and temperature on self-assembly of ordered porous surface were studied. Furthermore, the influence of surface energy of drop-casting substrates was additionally investigated. With a human cervical epithelial carcinoma cell line (HeLa), cytotoxicity of the prepared honeycomb-structured films by new amphiphile C6 was evaluated by thiazoyl-blue-tetrazolium-bromide (MTT) assay, and HeLa cell growth behavior with microporous amphiphile films as the scaffolds was also examined. It was found that tunable micropore diameter sizes and well ordered surface topologies of BF films could be achieved for the new prepared amphiphiles, and utilization of the honeycomb-like microporous films as scaffolds indicated favorable enhancement in cell proliferation. Therefore, the honeycomb-structured films by these biocompatible multifunctional amphiphiles may provide new materials as 3D-scaffold materials for potential application in tissue engineering and regeneration.
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Lentviral-mediated RNAi to inhibit target gene expression of the porcine integrin ?v subunit, the FMDV receptor, and against FMDV infection in PK-15 cells.
Virol. J.
PUBLISHED: 06-07-2011
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shRNA targeting the integrin ?v subunit, which is the foot-and-mouth disease virus (FMDV) receptor, plays a key role in virus attachment to susceptible cells. We constructed a RNAi lentiviral vector, i?v pLenti6/BLOCK -iT™, which expressed siRNA targeting the FMDV receptor, the porcine integrin ?v subunit, on PK-15 cells. We also produced a lentiviral stock, established an i?v-PK-15 cell line, evaluated the gene silencing efficiency of mRNA using real-time qRT-PCR, integrand ?v expression by indirect immunofluorescence assay (IIF) and cell enzyme linked immunosorbent assays (cell ELISA), and investigated the in vivo inhibitory effect of shRNA on FMDV replication in PK-15 cells.
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DNA diagnostics with a bacterial reporter probe.
Chem. Commun. (Camb.)
PUBLISHED: 05-03-2011
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A DNA diagnostic system has been developed by using a bacterial reporter probe. DNA hybridization-driven magnetic isolation of E. coli, followed by exponential bacterial growth and fluorescent protein expression, allows the translation of a target binding event into a vastly amplified signal and a highly sensitive/selective detection platform.
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Miniature endoscopic optical coherence tomography probe employing a two-axis microelectromechanical scanning mirror with through-silicon vias.
J Biomed Opt
PUBLISHED: 03-03-2011
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We present the design and experimental results of a new MEMS-based endoscopic optical coherence tomography (OCT) probe. The uniqueness of this miniature OCT imaging probe is a two-axis MEMS mirror with through-silicon vias (TSVs) for interconnecting. The TSV interconnection enables ultracompact probe design, successfully reducing the probe size to only 2.6 mm in diameter. The MEMS mirror is actuated by an electrothermal actuator that is capable of scanning ± 16° at only 3.6 V DC. Two-dimensional and three-dimensional OCT images of microspheres embedded in PDMS and acute rat brain tissue have been obtained with this miniature probe in a time-domain OCT system.
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The intracellular plasmid DNA localization of cationic reducible cholesterol-disulfide lipids.
Biomaterials
PUBLISHED: 01-13-2011
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Stimuli-responsive biomaterials derived from natural products toward efficient drug/gene delivery have been attracting increasing attention in the past decade. In this work, we first designed and prepared a new series of cholesterol-disulfide lipids, namely CHOSS-N, CHOSS-N+, CHOSS-Lys and CHOSS-4N bearing cholesterol and a variety of headgroups via disulfide and carbonate bond linkages, and their molecular structures were characterized by NMR and ESI-MS. Furthermore, plasmid DNA binding affinity for these new CHOSS lipids was separately examined by ethidium bromide displacement and agarose-gel retardant assay. Average diameter sizes and surface potentials of the CHOSS/pDNA lipoplex particles prepared under various N/P charge ratios were analyzed by dynamic laser light scattering (DLS). Under 10 mm dithiothreitol (DTT), stability and disassembly of the CHOSS/pDNA lipoplex nanoparticles were investigated by agarose-gel retardant assay and atomic force microscopy (AFM). Employing a COS-7 cell line, cell viability was examined for the prepared CHOSS lipids and their pDNA lipoplexes with branched PEI-25k as the reference. Finally, COS-7 cell gene transfection efficacies with these CHOSS lipids as potential delivery vectors were investigated by luciferase and EGFP transfection assay in the absence and presence of serum, and intracellular uptake capability, trafficking and cellular localization of Cy3-labeled pEGFP-N1 DNA were studied with a flow cytometer and fluorescent microscopy with Lipofectamine™ 2000 as the control. The results demonstrated low cytotoxicity, strong pDNA binding affinity and high transgenetic efficacy for new prepared CHOSS lipids, and particularly high intracellular uptake capability and specific cellular localization of pDNA at the periphery of cell nuclei were for the first time interestingly observed for the CHOSS lipid delivery carriers. In general, these may pave a new way to utilize cholesterol, amino acids and other functional natural products to prepare efficient gene/drug delivery carriers with simple structure and low cytotoxicity.
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Photoacoustic imaging based on MEMS mirror scanning.
Biomed Opt Express
PUBLISHED: 08-23-2010
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A microelectromechanical systems (MEMS)-based photoacoustic imaging system is reported for the first time. In this system, the MEMS-based light scanning subsystem and a ring-shaped polyvinylidene fluoride (PVDF) transducer are integrated into a miniaturized probe that is capable of three-dimensional (3D) photoacoustic imaging. It is demonstrated that the imaging system is able to image small objects embedded in phantom materials and in chicken and to in vivo visualize blood vessels under the skin of a human hand.
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3D in vivo optical coherence tomography based on a low-voltage, large-scan-range 2D MEMS mirror.
Opt Express
PUBLISHED: 07-01-2010
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3D in vivo optical imaging on a mouse has been obtained using a 2D MEMS mirror for lateral scanning in a time-domain optical coherence tomography (OCT) system. The MEMS mirror aperture size is 1 x 1 mm(2), and the device footprint is 2 x 2 mm(2). The MEMS mirror scans +/- 30 degrees optical angles about both x and y-axis at only 5.5V DC voltage. An endoscopic probe with an outer diameter of 5.8 mm has been designed, manufactured and packaged. The probe scans an average transverse area of 2 mm x 2 mm. The imaging speed of the probe is about 2.5 frames per second, limited by the speed of the employed optical delay line.
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Comparison of pulsed photothermal radiometry, optical coherence tomography and ultrasound for melanoma thickness measurement in PDMS tissue phantoms.
J Biophotonics
PUBLISHED: 06-29-2010
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Melanoma accounts for 75% of all skin cancer deaths. Pulsed photothermal radiometry (PPTR), optical coherence tomography (OCT) and ultrasound (US) are non-invasive imaging techniques that may be used to measure melanoma thickness, thus, determining surgical margins. We constructed a series of PDMS tissue phantoms simulating melanomas of different thicknesses. PPTR, OCT and US measurements were recorded from PDMS tissue phantoms and results were compared in terms of axial imaging range, axial resolution and imaging time. A Monte Carlo simulation and three-dimensional heat transfer model was constructed to simulate PPTR measurement. Experimental results show that PPTR and US can provide a wide axial imaging range (75 ?m-1.7 mm and 120-910 ?m respectively) but poor axial resolution (75 and 120 ?m respectively) in PDMS tissue phantoms, while OCT has the most superficial axial imaging range (14-450 ?m) but highest axial resolution (14 ?m). The Monte Carlo simulation and three-dimensional heat transfer model give good agreement with PPTR measurement. PPTR and US are suited to measure thicker melanoma lesions (>400 ?m), while OCT is better to measure thin melanoma lesions (<400 ?m).
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Preoperative CTLA-4 blockade: tolerability and immune monitoring in the setting of a presurgical clinical trial.
Clin. Cancer Res.
PUBLISHED: 05-11-2010
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Cytotoxic T lymphocyte associated antigen (CTLA-4) blockade is being explored in numerous clinical trials as an immune-based therapy for different malignancies. Our group conducted the first preoperative clinical trial with the anti-CTLA-4 antibody ipilimumab in 12 patients with localized urothelial carcinoma of the bladder.
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Inactivation of Msx1 and Msx2 in neural crest reveals an unexpected role in suppressing heterotopic bone formation in the head.
Dev. Biol.
PUBLISHED: 04-06-2010
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In an effort to understand the morphogenetic forces that shape the bones of the skull, we inactivated Msx1 and Msx2 conditionally in neural crest. We show that Wnt1-Cre inactivation of up to three Msx1/2 alleles results in a progressively larger defect in the neural crest-derived frontal bone. Unexpectedly, in embryos lacking all four Msx1/2 alleles, the large defect is filled in with mispatterned bone consisting of ectopic islands of bone between the reduced frontal bones, just anterior to the parietal bones. The bone is derived from neural crest, not mesoderm, and, from DiI cell marking experiments, originates in a normally non-osteogenic layer of cells through which the rudiment elongates apically. Associated with the heterotopic osteogenesis is an upregulation of Bmp signaling in this cell layer. Prevention of this upregulation by implantation of noggin-soaked beads in head explants also prevented heterotopic bone formation. These results suggest that Msx genes have a dual role in calvarial development: They are required for the differentiation and proliferation of osteogenic cells within rudiments, and they are also required to suppress an osteogenic program in a cell layer within which the rudiments grow. We suggest that the inactivation of this repressive activity may be one cause of Wormian bones, ectopic bones that are a feature of a variety of pathological conditions in which calvarial bone development is compromised.
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3D polarization-sensitive optical coherence tomography of canine meniscus based on a 2D high-fill-factor microelectromechanical Mirror.
Conf Proc IEEE Eng Med Biol Soc
PUBLISHED: 12-08-2009
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A miniature optical imaging probe based on a high-fill-factor MEMS mirror has been developed for nondestructive diagnosis of articular joint diseases and injuries. The MEMS mirror scans +/-30 degrees at less than 6 V in both x- and y-axis. The outer diameter of the probe is 5.8 mm. Three-dimensional polarization-sensitive optical coherence tomography of canine meniscus has been successfully demonstrated.
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Response properties of electrically evoked potential elicited by multi-channel penetrative optic nerve stimulation in rabbits.
Doc Ophthalmol
PUBLISHED: 08-06-2009
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Visual prosthesis is a potential way to restore partial vision for the patients with degenerative retinal diseases such as retinitis pigmentosa (RP) and age-related macular degeneration (AMD). Optic nerve stimulation with penetrating microelectrode array has been suggested as a possible method for visual prosthesis. The purpose of this study was to investigate the feasibility and basic response properties of cortical responses elicited by optic nerve stimulation with penetrating electrodes in rabbits. In this study, three triangularly or linearly configured platinum-iridium wire electrodes were inserted into the optic nerves of rabbits for electrical stimulation. The charge-balanced current pulses with amplitudes ranging from 10 to 100 microA at 0.5 ms pulse duration were used as the electrical stimuli. The electrically evoked potentials (EEPs) were recorded with a 16-channel silver-ball electrode array in the rabbit visual cortex. Our experimental results showed that the activities of visual cortex could be effectively evoked by the optic nerve stimulation with penetrating electrodes. The threshold of current and charge density to elicit EEPs under optic nerve stimulation at 0.5 ms pulse duration was 20.3 +/- 7.5 microA and 37.8 +/- 13.9 microC/cm(2), respectively. Current stimuli with cathode-first pulses elicited larger cortical responses than that with anode-first pulses. The amplitude of P1 and extent of EEPs increased as the stimulating current amplitude increased, while the latency of P1 decreased. The spatial distributions of multi-channel EEPs in visual cortex demonstrated distinctively different properties under stimulation with different orientations of the stimulating electrodes.
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Reconstitution and engineering of apoptotic protein interactions on the bacterial cell surface.
J. Mol. Biol.
PUBLISHED: 05-25-2009
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The interactions between pro- and anti-apoptotic members of the Bcl-2 class of proteins control whether a cell lives or dies, and the study of these protein-protein interactions has been an area of intense research. In this report, we describe a new tool for the study and engineering of apoptotic protein interactions that is based on the flow cytometric detection of these interactions on the surface of Escherichia coli. After validation of the assay with the well-studied interaction between the Bak(72-87) peptide and the anti-apoptotic protein Bcl-x(L), the effect of both increasing and decreasing Bak peptide length on Bcl-x(L) binding was investigated. Previous work demonstrated that the Bak(72-87) peptide also binds to the anti-apoptotic protein Bcl-2, albeit with lower binding affinity compared to Bcl-x(L). Here, we demonstrate that a slightly longer Bak peptide corresponding to amino acids 72-89 of Bak binds Bcl-x(L) and Bcl-2 equally well. Approximate binding affinity calculations on these peptide-protein complexes confirm the experimental observations. The flow cytometric assay was also used to screen a saturation mutagenesis library of Bak(72-87) variants for improved affinity to Bcl-x(L). The best variants obtained from this library exhibit an apparent K(d) to Bcl-x(L) 4-fold lower than that of wild-type Bak(72-87).
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Sequence analysis of MYOC and CYP1B1 in a Chinese pedigree of juvenile glaucoma with goniodysgenesis.
Mol. Vis.
PUBLISHED: 03-24-2009
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This study was designed to analyze two candidate genes, myocilin (MYOC) and cytochrome P450 1B1 (CYP1B1), in a Chinese pedigree of juvenile glaucoma with goniodysgenesis.
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trans-1,2,3-Tris(4-methoxy-benzo-yl)cyclo-propane.
Acta Crystallogr Sect E Struct Rep Online
PUBLISHED: 02-12-2009
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In the title compound, C(27)H(24)O(6), the packing of the mol-ecules is mainly governed by C-H?O inter-actions.
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EphA4 as an effector of Twist1 in the guidance of osteogenic precursor cells during calvarial bone growth and in craniosynostosis.
Development
PUBLISHED: 02-10-2009
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Heterozygous loss of Twist1 function causes coronal synostosis in both mice and humans. We showed previously that in mice this phenotype is associated with a defect in the neural crest-mesoderm boundary within the coronal suture, as well as with a reduction in the expression of ephrin A2 (Efna2), ephrin A4 (Efna4) and EphA4 in the coronal suture. We also demonstrated that mutations in human EFNA4 are a cause of non-syndromic coronal synostosis. Here we investigate the cellular mechanisms by which Twist1, acting through Eph-ephrin signaling, regulates coronal suture development. We show that EphA4 mutant mice exhibit defects in the coronal suture and neural crest-mesoderm boundary that phenocopy those of Twist1(+/-) mice. Further, we demonstrate that Twist1 and EphA4 interact genetically: EphA4 expression in the coronal suture is reduced in Twist1 mutants, and compound Twist1-EphA4 heterozygotes have suture defects of greater severity than those of individual heterozygotes. Thus, EphA4 is a Twist1 effector in coronal suture development. Finally, by DiI labeling of migratory osteogenic precursor cells that contribute to the frontal and parietal bones, we show that Twist1 and EphA4 are required for the exclusion of such cells from the coronal suture. We suggest that the failure of this process in Twist1 and EphA4 mutants is the cause of craniosynostosis.
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Anti-CTLA-4 therapy results in higher CD4+ICOShi T cell frequency and IFN-gamma levels in both nonmalignant and malignant prostate tissues.
Proc. Natl. Acad. Sci. U.S.A.
PUBLISHED: 02-06-2009
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Cytotoxic lymphocyte antigen-4 (CTLA-4) blockade is an active immunotherapeutic strategy that is currently in clinical trials in cancer. There are several ongoing trials of anti-CTLA-4 in the metastatic setting of prostate cancer patients with reported clinical responses consisting of decreases in the prostate specific antigen (PSA) tumor marker for some patients. Immunologic markers that correlate with these clinical responses are necessary to guide further development of anti-CTLA-4 therapy in the treatment of cancer patients. We recently reported that CD4(+) inducible co-stimulator (ICOS)(hi) T cells that produce interferon-gamma (IFN-gamma) are increased in the peripheral blood and tumor tissues of bladder cancer patients treated with anti-CTLA-4 antibody. Here we present data from the same clinical trial in bladder cancer patients demonstrating a higher frequency of CD4(+)ICOS(hi) T cells and IFN-gamma mRNA levels in nonmalignant prostate tissues and incidental prostate tumor tissues removed at the time of radical cystoprostatectomy. Our data suggest immunologic markers that can be used to monitor prostate cancer patients who receive anti-CTLA-4 therapy and indicate that the immunologic impact of anti-CTLA-4 antibody can occur in both tumor and nonmalignant tissues. These data should be taken into consideration for evaluation of efficacy as well as immune-related adverse events associated with anti-CTLA-4 therapy.
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Preparation of functional water-soluble low-cytotoxic poly(methacrylate)s with pendant cationic L-lysines for efficient gene delivery.
Macromol Biosci
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In this work, we present the preparation of water-soluble poly(methacrylate)s with pendant cationic L-lysines PHMLs(6-30?K). Plasmid DNA binding affinity as well as particle sizes and zeta potentials of the polyplexes were examined for these PHML vectors, and their cytotoxicities were assayed with HeLa cells by CCK-8 and lactate dehydrogenase kits. Gene transfection efficacy and intracellular uptake of the polyplexes by the PHML vectors were also studied with HeLa cells. As a result, it was revealed that the low cytotoxic PHMLs tended to exhibit gene transfection efficiencies significantly higher than those of the linear structural PLL (15-30?K) control, in particular the molecular weight of a PHML vector remarkably influenced its pDNA binding affinity, transfection efficacy and intracellular uptake of the polyplexes.
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Imperatorin attenuates LPS-induced inflammation by suppressing NF-?B and MAPKs activation in RAW 264.7 macrophages.
Inflammation
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Imperatorin is a type of coumarin compound with antibacterial and antiviral activities. In the present study, we examined the anti-inflammatory effects of imperatorin in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages by investigating its impact on the production and expression of cytokines and the major signal-transduction pathways. We found that imperatorin downregulated LPS-induced levels of TNF-?, IL-1?, and IL-6 in RAW 264.7 macrophages in a concentration-dependent manner, and it significantly inhibited expression of TNF-? and IL-6 (P?
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Novel ISCR1-linked resistance genes found in multidrug-resistant Gram-negative bacteria in southern China.
Int. J. Antimicrob. Agents
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Non-duplicate multidrug-resistant (MDR) Gram-negative bacteria (n=1329) isolated from southern China between January 2008 and December 2009 were investigated for the presence of ISCR1 as well as characterisation of ISCR1-linked resistance genes. Of 433 ISCR1-positive strains, 151 appeared to carry ISCR1-linked resistance genes. Seven different ISCR1-linked resistance gene arrays were identified by restriction fragment length polymorphism (RFLP) and DNA sequencing analysis. Many of these arrays are reported in some species for the first time. A total of 12 genes, including a novel ABC transporter (GenBank accession no. GU944725), qnrA1, qnrB2, qnrB6, bla(DHA-1), ampR, bla(CTX-M-9), bla(PER-1), insB, sapA-like peptide transport periplasmic protein, putative glutathione S-transferase and short-chain dehydrogenase/reductase, were detected. This study was the first to employ PCR-RFLP using HinfI and RsaI to analyse ISCR1-linked genes. ISCR1 was widely disseminated among MDR Gram-negative bacteria and was in close association with quinolone resistance and ?-lactamase genes (class A and class C) in southern China.
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Preventive effect of Imperatorin on acute lung injury induced by lipopolysaccharide in mice.
Int. Immunopharmacol.
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Imperatorin, a linear furanocoumarin, has many pharmacological effects such as antibacterial, anti-inflammatory and antiviral effects. The purpose of this study was to investigate the effect of Imperatorin on lipopolysaccharide (LPS)-induced acute lung injury (ALI) in mice. BALB/c mice were pretreated with Imperatorin 1h before LPS challenge. We found that the levels of tumor necrosis factor-? (TNF-?), interleukin-1? (IL-1?) and interleukin-6 (IL-6) in the bronchoalveolar lavage fluid (BALF) were decreased significantly, and the level of interleukin-10 (IL-10) was up-regulated 8h after Imperatorin treatment. Pretreatment with Imperatorin (15 or 30 mg/kg) decreased lung wet-to-dry weight (W/D) ratio, the number of inflammatory cells and myeloperoxidase (MPO) activities. Additionally, Imperatorin attenuated lung histopathological changes and significantly inhibited the phosphorylation of I?B, JNK, ERK and p38/MAPK. These findings demonstrate that Imperatorin protects against LPS-induced ALI in mice.
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Measuring volumetric change after augmentation mammaplasty using a three-dimensional scanning technique: an innovative method.
Aesthetic Plast Surg
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Measurement of volumetric change after augmentation mammaplasty is of great significance to plastic surgeons. This study aimed to introduce a new method using a three-dimensional (3D) scanning technique to measure volumetric change after augmentation mammaplasty.
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Class 1 integron gene cassettes in multidrug-resistant Gram-negative bacteria in southern China.
Int. J. Antimicrob. Agents
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Non-duplicate multidrug-resistant Gram-negative bacteria (n=1447) isolated from January 2008 to December 2009 were investigated for the presence of integrons as well as characterisation of gene cassettes. Among 825 strains carrying the class 1 integrase gene intI1, 461 gene cassette-positive isolates were found. Thirty-eight distinct gene cassette arrays were identified by restriction fragment length polymorphism (RFLP) and DNA sequencing analyses. In addition, several novel gene cassette arrays detected in this study were reported for the first time in some species: one in Escherichia coli, six in Klebsiella pneumoniae, six in Enterobacter cloacae, three in Enterobacter aerogenes, one in Proteus mirabilis, one in Acinetobacter spp., one in Stenotrophomonas maltophilia and one in Pseudomonas putida. Among them, three cassettes, including HAD-like, ?MFS-1 and qnrVC-like genes, were originally detected in integrons.
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Simultaneous measurement of electro-optical and converse-piezoelectric coefficients of PMN-PT ceramics.
Opt Express
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A new scheme is proposed to measure the electro-optical (EO) and converse-piezoelectric (CPE) coefficients of the PMN-PT ceramics simultaneously, in which the PMN-PT ceramics acts as the guiding layer of a symmetrical metal-cladding waveguide. As the applied electric field exerts on the waveguide, the effective refractive index (RI) (or synchronous angle) can be effectively tuned from a selected mode to another adjacent mode owing to the high sensitivity and the small spacing of the ultra-high order modes. Subsequently, a correlation between EO and CPE coefficients is established. With this correlation and the measurement of the effective RI change to the applied voltage, the quadratic EO and CPE coefficients of PMN-PT ceramics are obtained simultaneously. The obtained results are further checked by fitting the variations of effective RI to a quadratic function. Our measurement method can be extended to a wide range of other materials.
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Evaluation of breast tumor margins in vivo with intraoperative photoacoustic imaging.
Opt Express
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The use of photoacoustic effect is a promising approach for biomedical imaging in living tissues. Photoacoustic tomography (PAT) has been demonstrated to image breast cancer, brain vasculature, arthritis and seizure focus owing to its rich optical contrast and high resolution in a single imaging modality. Here we report a microelectromechanical systems (MEMS)-based intraoperative PAT (iPAT) technique, and demonstrate its ability to accurately map tumors in three-dimension and to inspect the completeness of tumor resection during surgery in a tumor-bearing mouse model. The MEMS imaging probe is small and has the potential to be conveniently used to guide surgical resection of tumors in the breast.
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Evaluation of a MEMS-based dual metal-layer thin-film microelectrode array for suprachoroidal electrical stimulation.
IEEE Trans Neural Syst Rehabil Eng
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A double metal-layer thin-film platinum microelectrode array was fabricated for implantation between sclera and choroid based on MEMS processing techniques and photosensitive polyimide material. The array was composed of 60 stimulating sites (6 × 10) and four selectable returning electrodes. The diameter of each stimulating electrode was 350 ? m with a center-to-center spacing of 750 ?m. The transient voltage responses of the electrode to current pulse stimulation indicated a charge-injection capacity greater than 52.1 ? C/cm (2) . Acute in vivo animal experiments showed that the implicit time of electrically evoked potentials (EEPs) was 17.09±1.45 ms at a threshold current of 25.55 ±5.43 ?A for a full-row of simultaneously stimulated electrodes (i.e., current applied simultaneously to each of the 10 electrodes). Individual electrode stimulation threshold was 48.57 ±6.90 ?A. The corresponding threshold charge densities were 13.28 ±2.82 ?C/cm (2) and 25.24 ±3.59 ?C/cm (2) , respectively. The spatial spread of the maximally recorded P1 response in the EEPs indicated a correspondence between the retinal stimulation site and the focal response location in the cortex. This method of array fabrication is suitable for acute suprachoroidal stimulation, and has a potential use for the fabrication of a visual prosthesis.
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Ultrafast kinetic DNA hybridization assay based on the visualization of threshold turbidity.
Anal. Chem.
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We report herein the development of an ultrafast kinetic DNA hybridization assay system based on the visualization of threshold turbidity associated with the assembly of polystyrene nanospheres. Initial testing of our diagnostic protocol on a sequence associated with the anthrax lethal factor indicates that a visually identifiable, turbidity-definitive, and kinetic threshold state could be reached at a time as short as 1 min. The assay scheme allows for both target concentration quantification and differentiation of single base mismatches through registry of the threshold turbidity onset time. The positively charged environment on nanospheres not only contributes to expedited signal generation but also imparts cooperative DNA binding properties. The kinetic visual protocol complements conventionally used thermodynamic strategies and provides an entry point for the circumvention of assay issues associated with ill-defined thermodynamic end points.
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Using independent component analysis to remove artifacts in visual cortex responses elicited by electrical stimulation of the optic nerve.
J Neural Eng
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In visual prosthesis research, electrically evoked potentials (EEPs) can be elicited by one or more biphasic current pulses delivered to the optic nerve (ON) through penetrating electrodes. Multi-channel EEPs recorded from the visual cortex usually contain large stimulus artifacts caused by instantaneous electrotonic current spread through the brain tissue. These stimulus artifacts contaminate the EEP waveform and often make subsequent analysis of the underlying neural responses difficult. This is particularly serious when investigating EEPs in response to electrical stimulation with long duration and multi-pulses. We applied independent component analysis (ICA) to remove these electrical stimulation-induced artifacts during the development of a visual prosthesis. Multi-channel signals were recorded from visual cortices of five rabbits in response to ON electrical stimulation with various stimulus parameters. ON action potentials were then blocked by lidocaine in order to acquire cortical potentials only including stimulus artifacts. Correlation analysis of reconstructed artifacts by ICA and artifacts recorded after blocking the ON indicates successful removal of artifacts from electrical stimulation by the ICA method. This technique has potential applications in studies designed to optimize the electrical stimulation parameters used by visual prostheses.
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Refractive index measurement of acute rat brain tissue slices using optical coherence tomography.
Opt Express
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An optical coherence tomography (OCT) system employing a microelectromechanical system (MEMS) mirror was used to measure the refractive index (RI) of anatomically different regions in acute brain tissue slices, in which viability was maintained. RI was measured in white-matter and grey-matter regions, including the cerebral cortex, putamen, hippocampus, thalamus and corpus callosum. The RI in the corpus callosum was found to be ~4% higher than the RIs in other regions. Changes in RI with tissue deformation were also measured in the cerebral cortex and corpus callosum under uniform compression (20-80% strain). For 80% strain, measured RIs increased nonlinearly by up to 70% and 90% in the cerebral cortex and corpus callosum respectively. Knowledge of RI in heterogeneous tissues can be used to correct distorted optical images caused by RI variations between different regions. Also deformation-dependent changes in RI can be applied to OCT elastography or to mechanical tests based on optical imaging such as indentation tests.
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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.

How does it work?

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.