共查询到20条相似文献,搜索用时 21 毫秒
1.
Objectives
To determine use of 2-[N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)amino]-2-deoxy-D-glucose (2-NBDG) as a tracer for detection of hypermetabolic circulating tumor cells (CTC) by fluorescence imaging.Procedures
Human breast cancer cells were implanted in the mammary gland fat pad of athymic mice to establish orthotopic human breast cancer xenografts as a mouse model of circulating breast cancer cells. Near-infrared fluorescence imaging of the tumor-bearing mice injected with 2-DeoxyGlucosone 750 (2-DG 750) was conducted to assess glucose metabolism of xenograft tumors. Following incubation with fluorescent 2-NBDG, circulating breast cancer cells in the blood samples collected from the tumor-bearing mice were collected by magnetic separation, followed by fluorescence imaging for 2-NBDG uptake by circulating breast cancer cells, and correlation of the number of hypermetabolic circulating breast cancer cells with tumor size at the time when the blood samples were collected.Results
Human breast cancer xenograft tumors derived from MDA-MB-231, BT474, or SKBR-3 cells were visualized on near-infrared fluorescence imaging of the tumor-bearing mice injected with 2-DG 750. Hypermetabolic circulating breast cancer cells with increased uptake of fluorescent 2-NBDG were detected in the blood samples from tumor-bearing mice and visualized by fluorescence imaging, but not in the blood samples from normal control mice. The number of hypermetabolic circulating breast cancer cells increased along with growth of xenograft tumors, with the number of hypermetabolic circulating breast cancer cells detected in the mice bearing MDA-MB231 xenografts larger than those in the mice bearing BT474 or SKBR-3 xenograft tumors.Conclusions
Circulating breast cancer cells with increased uptake of fluorescent 2-NBDG were detected in mice bearing human breast cancer xenograft tumors by fluorescence imaging, suggesting clinical use of 2-NBDG as a tracer for fluorescence imaging of hypermetabolic circulating breast cancer cells. 相似文献2.
Background
Activation of extracellular signal-regulated protein kinase (ERK), a member of mitogen-activated protein kinase (MAPK) family, has been proposed to mediate neurite outgrowth-promoting effects of several neurotrophic factors in vitro. However, the precise activity of ERK during axonal regeneration in vivo remains unclear. Peripheral axotomy has been shown to activate ERK in the cell bodies of primary afferent neurons and associated satellite cells. Nevertheless, whether ERK is also activated in the axons and surrounded Schwann cells which also play a key role in the regeneration process has not been clarified.Results
Phosphorylation of ERK in the sciatic nerve in several time-points after crush injury has been examined. Higher phosphorylation of ERK was observed in the proximal and distal nerve stumps compared to the contralateral intact nerve from one day to one month after crush. The activation of ERK was mainly localized in the axons of the proximal segments. In the distal segments, however, active ERK was predominantly found in Schwann cells forming Bungner's bands.Conclusion
The findings indicate that ERK is activated in both the proximal and distal nerve stumps following nerve injury. The role of activated ERK in Wallerian degeneration and subsequent regeneration in vivo remains to be elucidated. 相似文献3.
4.
4-Hetero-1-yl-2-bromothieno[3,2-c]pyridines 3(a–d) were synthesized by the reaction of 2-bromo-4-chlorothieno[3,2-c]pyridine (1) and cyclic amine 2(a–d), which on Suzuki coupling with substituted boronic acids 4(a–f) exclusively converted to corresponding 4-hetero -1-yl-2-arylthieno[3,2-c]pyridine 5(a–x) in good yields. The effect of donor-acceptor substituent on absorption emission properties and fluorescent quantum yield of new thienopyridine derivatives 5(a-x) were studied. 相似文献
5.
Myriam Gastard 《BMC neuroscience》2000,1(1):1-6
Background
The delta(δ)-opioid receptors belong to the G protein-coupled receptors and in vitro studies have shown that δ-opioid receptors undergo an internalization process in response to agonist stimulation. The immediate consequence is the disappearance of receptors from the plasma membrane. This adaptation process reveals the cell's capacity to desensitize after a strong agonist stimulus. This process, if it occurs in vivo, could contribute to the tolerance phenomenon observed after opiate treatment. To study the mechanisms underlying regulation of the δ-opioid receptors in vivo, the effects of an application of the drug dermenkephalin, a potent and selective agonist of the δ-opioid receptor, were analysed in the rat spinal cord.Results
Using immunocytochemistry and electron microscopy, we observed in control rats that membrane labelling was strictly localized at the interface between two neurites. Fifteen minutes after dermenkephalin stimulation, the plasma membrane labelling was associated with invaginated areas. Thirty minutes after stimulation, labelled vesicles were found in the cytoplasm confirming the internalization process.Conclusions
The present findings support the view that δ-opioid receptors are internalized in response to prolonged exposure to dermenkephalin in vivo and confirm the presynaptic localization of δ-opioid receptors in the dorsal horn of the rat spinal cord. 相似文献6.
Fabian Heisig Sabrina Gollos Sven J. Freudenthal Ali El-Tayeb Jamshed Iqbal Christa E. Müller 《Journal of fluorescence》2014,24(1):213-230
The goal of the present study was to design small, functionalized green-emitting BODIPY dyes, which can readily be coupled to target molecules such as receptor ligands, or even be integrated into their pharmacophores. A simple two-step one-pot procedure starting from 2,4-dimethylpyrrole and ω-bromoalkylcarboxylic acid chlorides was used to obtain new ω-bromoalkyl-substituted BODIPY fluorophores (1a–1f) connected via alkyl spacers of different length to the 8-position of the fluorescent dye. The addition of radical inhibitors reduced the amount of side products. The ω-bromoalkyl-substituted BODIPYs were further converted to introduce various functional groups: iodo-substituted dyes were obtained by Finkelstein reaction in excellent yields; microwave-assisted reaction with methanolic ammonia led to fast and clean conversion to the amino-substituted dyes; a hydroxyl-substituted derivative was prepared by reaction with sodium ethylate, and thiol-substituted BODIPYs were obtained by reaction of 1a–1f with potassium thioacetate followed by alkaline cleavage of the thioesters. Water-soluble derivatives were prepared by introducing sulfonate groups into the 2- and 6-position of the BODIPY core. The synthesized BODIPY derivatives showed high fluorescent yields and appeared to be stable under basic, reducing and oxidative conditions. As a proof of concept, 2-thioadenosine was alkylated with bromoethyl-BODIPY 1b. The resulting fluorescent 2-substituted adenosine derivative 15 displayed selectivity for the A3 adenosine receptor (ARs) over the other AR subtypes, showed agonistic activity, and may thus become a useful tool for studying A3ARs, or a lead structure for further optimization. The new functionalized dyes may be widely used for fluorescent labeling allowing the investigation of biological targets and processes. 相似文献
7.
Fu Xiong Shaobo Xiao Meijuan Yu Wanyi Li Hui Zheng Yanchang Shang Funing Peng Cuiping Zhao Wenliang Zhou Huanchun Chen Liurong Fang Jeffrey S Chamberlain Cheng Zhang 《BMC neuroscience》2007,8(1):1-9
Background
Duchenne musclar dystrophy (DMD) is an X-linked recessive disease caused by mutations of dystrophin gene, there is no effective treatment for this disorder at present. Plasmid-mediated gene therapy is a promising therapeutical approach for the treatment of DMD. One of the major issues with plasmid-mediated gene therapy for DMD is poor transfection efficiency and distribution. The herpes simplex virus protein VP22 has the capacity to spread from a primary transduced cell to surrounding cells and improve the outcome of gene transfer. To improve the efficiency of plasmid-mediated gene therapy and investigate the utility of the intercellular trafficking properties of VP22-linked protein for the treatment for DMD, expression vectors for C-terminal versions of VP22-microdystrophin fusion protein was constructed and the VP22-mediated shuttle effect was evaluated both in vitro and in vivo.Results
Our results clearly demonstrate that the VP22-microdystrophin fusion protein could transport into C2C12 cells from 3T3 cells, moreover, the VP22-microdystrophin fusion protein enhanced greatly the amount of microdystrophin that accumulated following microdystrophin gene transfer in both transfected 3T3 cells and in the muscles of dystrophin-deficient (mdx) mice.Conclusion
These results highlight the efficiency of the VP22-mediated intercellular protein delivery for potential therapy of DMD and suggested that protein transduction may be a potential and versatile tool to enhance the effects of gene delivery for somatic gene therapy of DMD. 相似文献8.
Charles A Gullo William YK Hwang Chye K Poh Melvin Au Geraline Cow Gerrard Teoh 《Journal of immune based therapies and vaccines》2008,6(1):1-10
Background
As the eradication of tumor cells in vivo is most efficiently performed by cytolytic T lymphocytes (CTL), various methods for priming tumor-reactive lymphocytes have been developed. In this study, a method of priming CTLs with ultraviolet (UV)-irradiated tumor cells, which results in termination of tumor cell proliferation, apoptosis, as well as upregulation of heat shock proteins (HSP) expression is described.Methods
Peripheral blood mononuclear cells (PBMC) were primed weekly with UV-irradiated or mitomycin-treated RPMI 8226 multiple myeloma cells. Following three rounds of stimulation over 21 days, the lymphocytes from the mixed culture conditions were analyzed for anti-MM cell reactivity.Results
By day 10 of cultures, PBMCs primed using UV-irradiated tumor cells demonstrated a higher percentage of activated CD8+/CD4- T lymphocytes than non-primed PBMCs or PBMCs primed using mitomycin-treated MM cells. Cytotoxicity assays revealed that primed PBMCs were markedly more effective (p < 0.01) than non-primed PBMCs in killing RPMI 8226 MM cells. Surface expression of glucose regulated protein 94 (Grp94/Gp96) and Grp78 were both found to be induced in UV-treated MM cells.Conclusion
Since, HSP-associated peptides are known to mediate tumor rejection; these data suggest that immune-mediated eradication of MM cells could be elicited via a UV-induced HSP process. The finding that the addition of 17-allylamide-17-demethoxygeldanamycin (17AAG, an inhibitor of HSP 90-peptide interactions) resulted in decreased CTL-induced cytotoxicity supported this hypothesis. Our study, therefore, provides the framework for the development of anti-tumor CTL cellular vaccines for treating MM using UV-irradiated tumor cells as immunogens. 相似文献9.
Brian Drozdowski Yuhong Zhou Brad Kline Jared Spidel Yin Yin Chan Earl Albone Howard Turchin Qimin Chao Marianne Henry Jacqueline Balogach Eric Routhier Sina Bavari Nicholas C Nicolaides Philip M Sass Luigi Grasso 《Journal of immune based therapies and vaccines》2010,8(1):1-9
Background
Staphylococcal enterotoxins are considered potential biowarfare agents that can be spread through ingestion or inhalation. Staphylococcal enterotoxin B (SEB) is a widely studied superantigen that can directly stimulate T-cells to release a massive amount of proinflammatory cytokines by bridging the MHC II molecules on an antigen presenting cell (APC) and the Vβ chains of the T-cell receptor (TCR). This potentially can lead to toxic, debilitating and lethal effects. Currently, there are no preventative measures for SEB exposure, only supportive therapies.Methods
To develop a potential therapeutic candidate to combat SEB exposure, we have generated three human B-cell hybridomas that produce human monoclonal antibodies (HuMAbs) to SEB. These HuMAbs were screened for specificity, affinity and the ability to block SEB activity in vitro as well as its lethal effect in vivo.Results
The high-affinity HuMAbs, as determined by BiaCore analysis, were specific to SEB with minimal crossreactivity to related toxins by ELISA. In an immunoblotting experiment, our HuMAbs bound SEB mixed in a cell lysate and did not bind any of the lysate proteins. In an in vitro cell-based assay, these HuMAbs could inhibit SEB-induced secretion of the proinflammatory cytokines (INF-γ and TNF-α) by primary human lymphocytes with high potency. In an in vivo LPS-potentiated mouse model, our lead antibody, HuMAb-154, was capable of neutralizing up to 100 μg of SEB challenge equivalent to 500 times over the reported LD50 (0.2 μg), protecting mice from death. Extended survival was also observed when HuMAb-154 was administered after SEB challenge.Conclusion
We have generated high-affinity SEB-specific antibodies capable of neutralizing SEB in vitro as well as in vivo in a mouse model. Taken together, these results suggest that our antibodies hold the potential as passive immunotherapies for both prophylactic and therapeutic countermeasures of SEB exposure. 相似文献10.
Muhammad Saleem Anser Ali Chang-Shik Choi Bong Joo Park Eun Ha Choi Ki Hwan Lee 《Journal of fluorescence》2014,24(4):995-1001
In recent years, fluorescent probes for the detection of environmentally and biologically important metal cations have received extensive attention for designing and development of fluorescent chemosensors. Herein, we report the photophysical results of 2-(2-fluorobenzoyl)-N-(2-methoxyphenyl) hydrazinecarbothioamide (4) functionalized as Ni (II) sensor in micromolar concentration level. Through fluorescence titration at 488 nm, we were confirmed that ligand 4 showed the remarkable emission by complexation between 4 and Ni (II) while it appeared no emission in case of the competitive ions (Cr3+, Fe2+, Co2+, Ba2+, Cu2+, Ca2+, Na+, K+, Cu+, Cs+). Furthermore, ligand 4 exhibited no toxicity with precise cell permeability toward normal living cells using L929 cell lines in bio imaging experiment investigated through confocal fluorescence microscope. The non-toxic behavior of ligand 4 (assessed by MTT assay) and its ability to track the Ni2+ in living cells suggest its possibility to use in biological system as nickel sensor. Figure
? 相似文献
11.
Purpose
The regional uptake of glucose in rat brain in vivo was measured at high resolution using spin-lock magnetic resonance imaging after infusion of the glucose analogue 2-deoxy-d-glucose (2DG). Previous studies of glucose metabolism have used 13C-labeled 2DG and NMR spectroscopy, 18F-labeled fluorodeoxyglucose (FDG) and PET, or chemical exchange saturation transfer (CEST) MRI, all of which have practical limitations. Our goal was to explore the ability of spin-lock sequences to detect specific chemically-exchanging species in vivo and to compare the effects of 2DG in brain tissue on CEST images.Methods
Numerical simulations of R1p and CEST contrasts for a variety of sample parameters were performed to evaluate the potential specificity of each method for detecting the exchange contributions of 2DG. Experimental measurements were made in tissue phantoms and in rat brain in vivo which demonstrated the ability of spin-lock sequences for detecting 2DG.Results
R1p contrast acquired with appropriate spin-lock sequences can isolate the contribution of exchanging protons in 2DG in vivo and appears to have better sensitivity and more specificity to 2DG–water exchange effects than CEST.Conclusion
Spin-lock imaging provides a novel approach to the detection and measurement of glucose uptake in brain in vivo. 相似文献12.
13.
Sebastian Illes Stephan Theiss Hans-Peter Hartung Mario Siebler Marcel Dihné 《BMC neuroscience》2009,10(1):1-16
Background
Minocycline, a second-generation tetracycline with anti-inflammatory and anti-apoptotic properties, has been shown to promote therapeutic benefits in experimental stroke. However, equally compelling evidence demonstrates that the drug exerts variable and even detrimental effects in many neurological disease models. Assessment of the mechanism underlying minocycline neuroprotection should clarify the drug's clinical value in acute stroke setting.Results
Here, we demonstrate that minocycline attenuates both in vitro (oxygen glucose deprivation) and in vivo (middle cerebral artery occlusion) experimentally induced ischemic deficits by direct inhibition of apoptotic-like neuronal cell death involving the anti-apoptotic Bcl-2/cytochrome c pathway. Such anti-apoptotic effect of minocycline is seen in neurons, but not apparent in astrocytes. Our data further indicate that the neuroprotection is dose-dependent, in that only low dose minocycline inhibits neuronal cell death cascades at the acute stroke phase, whereas the high dose exacerbates the ischemic injury.Conclusion
The present study advises our community to proceed with caution to use the minimally invasive intravenous delivery of low dose minocycline in order to afford neuroprotection that is safe for stroke. 相似文献14.
Novel carbazole based styryl derivatives (6a–6c) having styryl group at third position and a methoxy substitution were synthesized by condensing 4-methoxy-9-methyl-9H-carbazole-3-carbaldehyde 3 and different active methylene derivatives (5a–5c). Evaluated photophysical properties of these synthesized novel chromophores, studied the effect of solvent polarity on absorption, emission and quantum yield of these styryl derivatives. DFT and TD-DFT computations are carried out to study structural, molecular, electronic and photophysical parameters of dyes. The ratio of ground state to excited state dipole moment was calculated using Bakhshiev and Kawski-Chamma-Viallet correlations. 相似文献
15.
Blue light-emitting spiro[benzotetraphene-fluorene] (SBTF)-based host materials, 3-(1-naphthyl)-10-naphthylspiro[benzo[ij]tetraphene-7,9′-fluorene] (1), 3-(2-naphthyl)-10-naphthylspiro[benzo[ij]tetraphene-7,9′-fluorene] (2), and 3-[2-(6-phenyl)naphthyl]-10-naphthylspiro[benzo[ij]tetraphene-7,9′-fluorene] (3) were designed and prepared via multi-step Suzuki coupling reactions. Introducing various aromatic groups into SBTF core lead to a reduction in band gap and a determination of the color purity and luminescence efficiency. Typical sky-blue fluorescent organic light emitting diodes with the configuration of ITO/N,N′-di(1-naphthyl)-N,N′-bis[(4-diphenylamino)phenyl]-biphenyl-4,4′-diamie (60 nm)/N,N,N′,N′-tetra(1-biphenyl)-biphenyl-4,4′-diamine (30 nm)/host: dopant (30 nm, 5 %)/LG201 (electron transporting layer, 20 nm)/LiF/Al were developed using SBTF derivatives as a host material and p-bis(p-N,N-diphenyl-aminostyryl)benzene (DSA-Ph) as a sky-blue dopant material. A device obtained from three materials doped with DSA-Ph showed color purity of 0.148 and 0.239, a luminance efficiency of 7.91 cd/A, and an external quantum efficiency >4.75 % at 5 V. 相似文献
16.
Koji Tsunekawa Fumio Kondo Teruhiko Okada Guo-Gang Feng Lei Huang Naohisa Ishikawa Shoshiro Okada 《BMC neuroscience》2013,14(1):1-11
Background
Domoic acid (DA) is an excitatory amino acid analogue of kainic acid (KA) that acts via activation of glutamate receptors to elicit a rapid and potent excitotoxic response, resulting in neuronal cell death. Recently, DA was shown to elicit reactive oxygen species (ROS) production and induce apoptosis accompanied by activation of p38 mitogen-activated protein kinase (MAPK) in vitro. We have reported that WDR35, a WD-repeat protein, may mediate apoptosis in several animal models. In the present study, we administered DA to rats intraperitoneally, then used liquid chromatography/ion trap tandem mass spectrometry (LC-MS/MS) to identify and quantify DA in the brains of the rats and performed histological examinations of the hippocampus. We further investigated the potential involvement of glutamate receptors, ROS, p38 MAPK, and WDR35 in DA-induced toxicity in vivo.Results
Our results showed that intraperitoneally administered DA was present in the brain and induced neurodegenerative changes including apoptosis in the CA1 region of the hippocampus. DA also increased the expression of WDR35 mRNA and protein in a dose- and time-dependent manner in the hippocampus. In experiments using glutamate receptor antagonists, the AMPA/KA receptor antagonist NBQX significantly attenuated the DA-induced increase in WDR35 protein expression, but the NMDA receptor antagonist MK-801 did not. In addition, the radical scavenger edaravone significantly attenuated the DA-induced increase in WDR35 protein expression. Furthermore, NBQX and edaravone significantly attenuated the DA-induced increase in p38 MAPK phosphorylation.Conclusion
In summary, our results indicated that DA activated AMPA/KA receptors and induced ROS production and p38 MAPK phosphorylation, resulting in an increase in the expression of WDR35 in vivo. 相似文献17.
Bishwapran Kashyap Kaku Dutta Diganta Kumar Das Prodeep Phukan 《Journal of fluorescence》2014,24(3):975-981
Three new ferrocene based Schiff bases 4-{[(E)-ferrocenylmethylidene] amino}benzenethiol (1b), 3-{[(E)-ferrocenylmethylidene]amino} benzenethiol (1c), 2-{[(E)-ferrocenylmethylidene]amino} benzenethiol (1d) have been synthesized to study their sensor property to various metal ions. It has been observed that 1b is highly fluorescent and its fluorescence changes in presence of metal ions. It was further observed that compound 1b is highly selective towards Cd2+ ion in solution. 相似文献
18.
Man Li Di Zhang Yaqi Liu Peigang Ding Yong Ye Yufen Zhao 《Journal of fluorescence》2014,24(1):119-127
A novel colorimetric and off–on fluorescent chemosensor 2 was designed and synthesized, which showed reversible and highly selective and sensitive recognition toward Cr3+ over other examined metal ions in aqueous solution. Upon addition of Cr3+, the solution of chemosensor 2 resulted in a color change from colorless to obvious pink color, these significant changes in color could be used for naked-eye detection. Chemosensor 2 exhibited a stable response for Cr3+ in the range 0–10 μM with a detection limit of 1 ppm. Furthermore, fluorescence imaging experiments of Cr3+ ions in living MGC803 cells demonstrated its value of practical applications in biological systems. 相似文献
19.
P2X receptors are hetero-oligomeric proteins that function as membrane ion channels and are gated by extracellular ATP. The hP2X $_{3}$ subunit is a constituent of the channels on a subset of sensory neurons involved in pain signaling, where ATP released by damaged and inflamed tissue can initiate action potentials. Hence, the inhibition of ATP-activated P2X $_{3}$ receptor is an exciting approach for the treatment of inflammatory and neuropathic pain. Recently, the crystal structures of zebrafish P2X $_{4}$ (zP2X $_{4})$ were obtained in closed, apo state (PDB ID: 3I5D) and ATP-bound, open state (PDB ID: 4DW1). These structures were used to develop a homology model of human P2X $_{3}$ (hP2X $_{3})$ in order to identify through docking studies, the binding modes of known P2X $_{3}$ inhibitors and their key active site interactions, along with a pharmacophore-based 3D-QSAR model for a series of 136 Pyrid-2-yl and 2-CyanoPhenyl fused heterocyclic compounds. These 3D-QSAR models have been developed with different combinations of training and test set divisions obtained by random separation, Jarvis–Patrick clustering, K-means clustering and sphere exclusion methods. The best predictive 3D-QSAR model resulted in training set R $^{2 }$ of 0.75, internal test set Q $^{2}$ of 0.74, Pearson-R value of 0.87 and root mean square error of 0.37. The information generated by the pharmacophore model and docking analyses using the homology model provides valuable clues to design novel potent hP2X $_{3}$ inhibitors. 相似文献
20.
José Jiun-Shian Wu Wei-Pang Chang Hsi-Chien Shih Chen-Tung Yen Bai Chuang Shyu 《BMC neuroscience》2014,15(1):1-17