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Find video protocols related to scientific articles indexed in Pubmed.
Alpha-actinin 4 is Associated with Cancer Cell Motility and is a Potential Biomarker in Non-Small-Cell Lung Cancer.
J Thorac Oncol
PUBLISHED: 10-10-2014
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The differential expression and secretion of alpha-actinin 4 (ACTN4) in the lung cancer CL1-0 and CL1-5 cell lines has been reported in previous proteomics studies. The aim of this study is to investigate the functional properties of the ACTN4 protein in non-small-cell lung cancer cells (NSCLC) and evaluate its clinical value.
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The contribution of antibiotic resistance mechanisms in clinical Burkholderia cepacia complex isolates: an emphasis on efflux pump activity.
PLoS ONE
PUBLISHED: 08-25-2014
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Due to the limited information of the contribution of various antibiotic resistance mechanisms in clinical Burkholderia cepacia complex isolates, Antibiotic resistance mechanisms, including integron analysis, identification of quinolone resistance-determining region mutations, measurement of efflux pump activity, and sequence analysis of efflux pump regulators, were investigated in 66 clinical B. cepacia complex isolates. Species were identified via recA-RFLP and MALDI-TOF. Four genomovars were identified by recA-RFLP. B. cenocepacia (genomovar III) was the most prevalent genomovar (90.1%). Most isolates (60/66, 90.9%) were correctly identified by MALDI-TOF analysis. Clonal relatedness determined by PFGE analysis revealed 30 pulsotypes, including two major pulsotypes that comprised 22.7% and 18.2% of the isolates, respectively. Seventeen (25.8%) isolates harboured class 1 integron with various combinations of resistance genes. Among six levofloxacin-resistant isolates, five had single-base substitutions in the gyrA gene and three demonstrated efflux pump activities. Among the 42 isolates exhibiting resistance to at least one antimicrobial agent, 94.4% ceftazidime-resistant isolates (17/18) and 72.7% chloramphenicol-resistant isolates (16/22) demonstrated efflux pump activity. Quantitation of efflux pump RNA level and sequence analysis revealed that over-expression of the RND-3 efflux pump was attributable to specific mutations in the RND-3 efflux pump regulator gene. In conclusion, high-level expression of efflux pumps is prevalent in B. cepacia complex isolates. Mutations in the RND-3 efflux pump regulator gene are the major cause of efflux pump activity, resulting in the resistance to antibiotics in clinical B. cepacia complex isolates.
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Evaluation of the antioxidant activity and antiproliferative effect of the jaboticaba (Myrciaria cauliflora) seed extracts in oral carcinoma cells.
Biomed Res Int
PUBLISHED: 03-29-2014
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It is becoming increasingly evident that certain phytochemicals possess cancer chemopreventive properties. In this study, the antiproliferative activity of extracts from different parts of the jaboticaba (Myrciaria cauliflora) plant was evaluated for its effect on human oral carcinoma cell lines. The cytotoxicities of various plant extract concentrations were examined and the 50% maximal inhibitory concentration (IC50) was determined. Water extracts of jaboticaba seeds showed concentration-dependent antiproliferative effects. Annexin V/propidium iodide positivity with active caspase-3 induction indicated that the treated cells underwent apoptosis. Several important regulatory proteins (Bcl-2, Bcl-xL, Bid, and survivin) involved in apoptosis were also evaluated. The antioxidant activity of jaboticaba was investigated using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azinobis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) assays, and the drug concentration eliciting 50% maximum stimulation (SC50) was determined. The present findings suggest that water extracts of jaboticaba seeds exhibit an antiproliferative effect against oral cancer cells by inducing apoptosis through downregulating survivin expression and thereby activating caspase-mediated Bid cleavage.
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A proteomic view to characterize the effect of chitosan nanoparticle to hepatic cells: is chitosan nanoparticle an enhancer of PI3K/AKT1/mTOR pathway?
Biomed Res Int
PUBLISHED: 02-10-2014
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Chitosan nanoparticle, a biocompatible material, was used as a potential drug delivery system widely. Our current investigation studies were the bioeffects of the chitosan nanoparticle uptake by liver cells. In this experiment, the characterizations of chitosan nanoparticles were measured by transmission electron microscopy and particle size analyzer. The average size of the chitosan nanoparticle was 224.6 ± 11.2?nm, and the average zeta potential was +14.08 ± 0.7?mV. Moreover, using proteomic approaches to analyze the differential protein expression patterns resulted from the chitosan nanoparticle uptaken by HepG2 and CCL-13 cells identified several proteins involved in the PI3K/AKT1/mTOR pathway. Our experimental results have demonstrated that the chitosan nanoparticle may involve in the liver cancer cell metastasis and proliferation.
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Characterization of silk fibroin modified surface: a proteomic view of cellular response proteins induced by biomaterials.
Biomed Res Int
PUBLISHED: 01-18-2014
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The purpose of this study was to develop the pathway of silk fibroin (SF) biopolymer surface induced cell membrane protein activation. Fibroblasts were used as an experimental model to evaluate the responses of cellular proteins induced by biopolymer material using a mass spectrometry-based profiling system. The surface was covered by multiwalled carbon nanotubes (CNTs) and SF to increase the surface area, enhance the adhesion of biopolymer, and promote the rate of cell proliferation. The amount of adhered fibroblasts on CNTs/SF electrodes of quartz crystal microbalance (QCM) greatly exceeded those on other surfaces. Moreover, analyzing differential protein expressions of adhered fibroblasts on the biopolymer surface by proteomic approaches indicated that CD44 may be a key protein. Through this study, utilization of mass spectrometry-based proteomics in evaluation of cell adhesion on biopolymer was proposed.
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A mild removal of Fmoc group using sodium azide.
Amino Acids
PUBLISHED: 10-03-2013
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A mild method for effectively removing the fluorenylmethoxycarbonyl (Fmoc) group using sodium azide was developed. Without base, sodium azide completely deprotected N (?)-Fmoc-amino acids in hours. The solvent-dependent conditions were carefully studied and then optimized by screening different sodium azide amounts and reaction temperatures. A variety of Fmoc-protected amino acids containing residues masked with different protecting groups were efficiently and selectively deprotected by the optimized reaction. Finally, a biologically significant hexapeptide, angiotensin IV, was successfully synthesized by solid phase peptide synthesis using the developed sodium azide method for all Fmoc removals. The base-free condition provides a complement method for Fmoc deprotection in peptide chemistry and modern organic synthesis.
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The synthetic flavonoid WYC02-9 inhibits cervical cancer cell migration/invasion and angiogenesis via MAPK14 signaling.
Gynecol. Oncol.
PUBLISHED: 08-26-2013
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Development of flavonoids as potential chemotherapeutic agents for cervical cancer may open new avenues in anticancer drug design. In this study, the cytotoxic activity and anti-migration/invasion/angiogenesis efficiency of the synthetic flavonoid WYC02-9 on cervical cancer and the underlying mechanisms are explored.
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Determination of phosphoserine/threonine by nano ultra-performance liquid chromatography-tandem mass spectrometry coupled with microscale labeling.
Anal. Biochem.
PUBLISHED: 07-14-2013
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Protein phosphorylation is an important regulatory post-translational modification in many biochemical processes. The phosphopeptide analysis strategies developed in this study were all at microscale. After using a standard microwave oven to assist protein digestion, phosphoserine and phosphothreonine were tagged with chemical analogues, such as 2-mercaptoethanol and 3-mercapto-1-propanol, to enable simultaneously relative quantitation and identification. This method enabled the use of thio alcohols for direct labeling of phosphorylated sites (not labeled at the mercapto, amino, hydroxyl, or carboxyl groups) of phosphopeptides. Various digestion parameters (e.g., microwave power, reaction time, NH4HCO3 concentration) and derivatization efficiency parameters (e.g., reaction time, labeling tag concentration) were studied and optimized. In both control and experimental samples, microwave-assisted digestion coupled with relative quantitation using analogue tags enabled calculation of phosphopeptide ratios in the same sequence. A non-labeling method was also established for quantifying phosphopeptides in human plasma by using the abundant protein albumin as an internal control for normalizing relative quantities of phosphopeptides. Nano ultra-performance liquid chromatography (nanoUPLC) was combined with LTQ Orbitrap to enable simultaneous protein relative quantitation and identification. These strategies proved to be effective for quantifying phosphopeptides in biological samples.
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Proteomic profiling for peritoneal dialysate: differential protein expression in diabetes mellitus.
Biomed Res Int
PUBLISHED: 03-22-2013
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Peritoneal dialysis (PD) is an increasingly accepted modality of renal replacement therapy. It provides the advantages of having a flexible lifestyle, stable hemodynamics, and better preservation of residual renal function. To enhance our understanding of the peritoneal dialysate of diabetes mellitus (DM), peritoneal dialysate proteins were identified by two-dimensional gel electrophoresis (2DE) combined with reverse-phase nano-ultra performance liquid chromatography electrospray ionization tandem mass spectrometry (RP-nano-UPLC-ESI-MS/MS) followed by peptide fragmentation patterning. To validate the differential proteins, ELISA and Western blotting analyses were applied to detect candidate proteins that may be related to DM. We performed 2DE on the peritoneal dialysate samples, with detection of more than 300 spots. From this, 13 spots were excised, in-gel digested, and identified by RP-nano-UPLC-ESI-MS/MS. Ten of these showed significant differential expression between the DM and chronic glomerulonephritis (CGN) peritoneal dialysate samples. In this study, we conducted a comparative proteomic study on these two groups of dialysate that may provide evidence for understanding the different peritoneal protein changes. These proteins may not be new biomarkers; however, they may indicate a situation for possible drug treatment and can be the predictors of peritonitis for a validation study in the future.
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Changes in retinal aquaporin-9 (AQP9) expression in glaucoma.
Biosci. Rep.
PUBLISHED: 03-08-2013
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The eye contains numerous water channel proteins and the roles of aquaporins in the retina are blurred, especially under disease conditions. The purpose of this study was to investigate the expression of aquaporin-9 (AQP9) gene and proteins affected by elevated intraocular pressure (IOP) in a rat model of glaucoma induced by intravitreous injection of hypertonic saline into the episcleral veins. Expression of AQP9 was investigated by real-time PCR and Western blotting. The immunoreactive expression of AQP9, AQP4 and glial fibrillary acidic protein (GFAP) in the optic nerve of rats exposed to experimentally elevated intraocular pressure was detected by immunofluorescence microscopy. The mRNA and protein expression levels of AQP9 were up-regulated in the retina of an animal model of glaucoma. The immunoreactivities of the AQP9, AQP4 and GFAP were also detected and increased in the optic nerve region. The expression of AQP9 was up-regulated in this glaucoma model and the immunoreactivities of the AQP4 and GFAP were also detected as co-localizing with AQP9 in the optic nerve region indicating retina ganglion cells were surrounded by activated astrocytes. This may indicate that the injured neurons may rely on the astrocytes. The alterations of aquaporin expression may compensate the glaucomatous damages.
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Properties of osteoconductive biomaterials: calcium phosphate cement with different ratios of platelet-rich plasma as identifiers.
Mater Sci Eng C Mater Biol Appl
PUBLISHED: 03-01-2013
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This study aims to evaluate further the performance of a platelet-rich plasma (PRP) additive incorporated with calcium phosphate bone cement (CPC) in vitro to prove its efficiency as bone graft substitutes and its compatibility to be incorporated into the CPC with other techniques in clinical restoration in vivo. The growth factor release ability and the osteogenic evaluation of PRP, CPC, and PRP/CPC testing groups with 5, 10, and 15 wt.% PRP were compared in vitro. Four groups were measured using non-decalcified staining methods in vivo, which include the testing group of 10 wt.% PRP/CPC selected from the evaluation in vitro, by using both the autograft with rabbit trabecular and CPC-only as comparison groups and the group without grafting material as the control sample. The results obtained through specimen immersion show that growth factor release and alkaline phosphatase activities after osteoprogenitor cell culture had a significantly better effect on 10 and 15 wt.% PRP/CPC than on the other groups in vitro. Analysis results suggest that PRP was still retained in the CPC matrix even after 32 days of immersion. The results in vivo show that the histology of the autograft bone and the control group without grafting material exhibited fibrous connective and adipose tissues, which obviously filled the created cavity even at nine weeks after the operation. Osteoregeneration was more successful in the PRP-additive group, which accumulated bone remodeling than in the other groups. In conclusion, CPC could be a potential carrier with adequate PRP additives that bear a therapeutic potential for enhanced bone tissue regeneration.
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Brain perfusion SPECT in patients with Behçets disease.
J Neuroradiol
PUBLISHED: 01-04-2013
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The aim of this study was to detect brain functional deficits in patients with Behçets disease (BD) and signs or symptoms of central nervous system (CNS) involvement at different times in their clinical history. A total of 24 patients aged 20 to 53years (median age 39years; 20 women, four men) with Behçets syndrome fulfilling the diagnosis as defined by the syndrome classification were enrolled in this study. Single-photon emission computed tomography (SPECT) with (99m)Technetium (Tc)-hexamethylpropyleneamine oxime (HMPAO) as the perfusion tracer was performed to detect brain lesions. The results of (99m)Tc-HMPAO brain SPECT scans showed impaired perfusion in all cases with neurological complaints (24 out of 24, 100%). Temporal lobes and basal ganglia were the most common areas with such lesions. In contrast, brain MRI and CT images were normal or non-specific in all cases. In conclusion, (99m)Tc-HMPAO brain SPECT imaging is a powerful and sensitive tool for disclosing brain involvement in numerous clinical situations, even including patients with subtle neurological symptoms/signs such as headaches and dizziness. It is also a useful modality for evaluating the effects of treatment and disease monitoring to prevent CNS damage.
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Urinary protein profiling by liquid chromatography/tandem mass spectrometry: ADAM28 is overexpressed in bladder transitional cell carcinoma.
Rapid Commun. Mass Spectrom.
PUBLISHED: 09-14-2011
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Bladder cancer is the most common urological cancer with higher incidence rate in the endemic areas of Blackfoot disease (BFD) in southern Taiwan. The aim of this study was to utilize the proteomic approach to establish urinary protein patterns of bladder cancer. The experimental results showed that most patients with bladder cancer had proteinuria or albuminuria. The urine arsenic concentrations of bladder cancer patients in BFD areas were significantly higher than those patients from non-BFD areas. In the proteomic analysis, the urinary proteome was identified by nano-high-performance liquid chromatography/electrospray ionization tandem mass spectrometry (nano-HPLC/ESI-MS/MS) followed by peptide fragmentation pattern analysis. We categorized 2782 unique proteins of which 89 proteins were identified with at least three unique matching peptide sequences. Among these 89 proteins, thirteen of them were not found in the control group and may represent proteins specific for bladder cancer. In this study, three proteins, SPINK5, ADAM28 and PTP1, were also confirmed by Western blotting and showed significant differential expression compared with the control group. ADAM28 may be used as a possible biomarker of bladder cancer.
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Characterization of ADAM28 as a biomarker of bladder transitional cell carcinomas by urinary proteome analysis.
Biochem. Biophys. Res. Commun.
PUBLISHED: 06-25-2011
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Human urine contains a large number of proteins and peptides (the urinary proteome). Global analysis of the human urinary proteome is important for understanding urinary tract diseases. Bladder cancer is the most common urological cancer with higher incidence rates in endemic areas of Blackfoot disease (BFD) in southern Taiwan. The aim of this study was to use the proteomic approach to establish urinary protein biomarkers of bladder cancer. ADAM28, identified by proteomic approaches and confirmed by Western blotting, showed significant differences compared with normal individuals, so it may be a biomarker of bladder cancer.
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Protein profiling of human nonpigmented ciliary epithelium cell secretome: the differentiation factors characterization for retinal ganglion cell line.
J. Biomed. Biotechnol.
PUBLISHED: 04-05-2011
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The purpose of this paper was to characterize proteins secreted from the human nonpigmented ciliary epithelial (HNPE) cells, which have differentiated a rat retinal ganglion cell line, RGC-5. Undifferentiated RGC-5 cells have been shown to express several marker proteins characteristic of retinal ganglion cells. However, RGC-5 cells do not respond to N-methyl-D aspartate (NMDA), or glutamate. HNPE cells have been shown to secrete numbers of neuropeptides or neuroproteins also found in the aqueous humor, many of which have the ability to influence the activity of neuronal cells. This paper details the profile of HNPE cell-secreted proteins by proteomic approaches. The experimental results revealed the identification of 132 unique proteins from the HNPE cell-conditioned SF-medium. The biological functions of a portion of these identified proteins are involved in cell differentiation. We hypothesized that a differentiation system of HNPE cell-conditioned SF-medium with RGC-5 cells can induce a differentiated phenotype in RGC-5 cells, with functional characteristics that more closely resemble primary cultures of rat retinal ganglion cells. These proteins may replace harsh chemicals, which are currently used to induce cell differentiation.
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Characterization of surface modification on self-assembled monolayer-based piezoelectric crystal immunosensor for the quantification of serum ?-fetoprotein.
J Mater Sci Mater Med
PUBLISHED: 03-30-2011
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Self-assembled monolayers (SAMs) on coinage metallic material can provide versatile modeling systems for studies of interfacial electron transfer, biological interactions, molecular recognition and other interfacial phenomena. Recently, a bio-sensing system has been produced by analysis of the attachment of antibody using alkanethiols, to form SAMs on the face of Au-quartz crystal microbalance (QCM) surfaces. In this study, the attachment of anti-?-fetoprotein monoclonal antibody to a SAMs surface of 11-mercaptoundecanoic acid was achieved using water-soluble N-ethyl-N-(3-dimethylaminopropyl) carbodiimide hydrochloride and N-hydroxysuccinimide as coupling agents. Surface analyses were utilized by X-ray photoelectron spectroscopy and atomic force microscopy. The quantization of immobilized antibody was characterized by the frequency shift of QCM and the radioactivity change of ¹²?I labeled antibody. The limit of detection and linear range of the calibration curve of the QCM method were 15 ng/ml and 15-850 ng/ml. The correlation coefficients of ?-fetoprotein concentration between QCM and radioimmunoassay were 0.9903 and 0.9750 for the standards and serum samples, respectively. This report illustrates an investigation of SAMs for the preparation of covalently immobilized antibody biosensors.
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Angiotensin-converting enzyme gene and plasma protein level in Alzheimers disease in Taiwanese.
Age Ageing
PUBLISHED: 01-13-2011
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angiotensin-converting enzyme (ACE) gene insertion/deletion (indel) polymorphism is considered a biomarker for Alzheimers disease (AD). However, the associations of ACE gene and protein level to AD are undetermined among Taiwanese.
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PCP copolymers grafted with RGD enhance the rates of RGD-PCP micelles internalized into cells.
J Microencapsul
PUBLISHED: 06-22-2010
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RGD-PCP copolymers were fabricated by grafting Arg-Gly-Asp (RGD) peptide to poly(epsilon-caprolactone)-b-chitooligosaccharide-b-poly(ethylene glycol) (PCP) copolymers and the rate of internalization of RGD-PCP micelles by PC 12 cells were examined. Increasing intensity of the absorbance of amine groups in FT-IR spectra of RGD-PCP copolymers compared with those of PCP copolymers indicated the presence of RGD in new copolymers. Moreover, the grafting efficiency and molar ratio of RGD peptides to PCP copolymers were 88.2% and 0.45, respectively, analysed with HPLC. The RGD-PCP copolymers self-assemble to micelles at the critical micelle concentration (CMC) of 0.018 wt% (178 mg L(-1)) and with a mean diameter of 90 nm using a dynamic light-scattering (DLS) analyser. Interestingly, the internalization of DPH-loaded RGD-PCP micelles into PC 12 cells is much faster (e.g. within 5 min) than that of PCP micelles. The new RGD-PCP micelles may potentially be used in cellular drug delivery.
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The Asia Oceania Human Proteome Organisation Membrane Proteomics Initiative. Preparation and characterisation of the carbonate-washed membrane standard.
Proteomics
PUBLISHED: 05-21-2010
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The Asia Oceania Human Proteome Organisation (AOHUPO) has embarked on a Membrane Proteomics Initiative with goals of systematic comparison of strategies for analysis of membrane proteomes and discovery of membrane proteins. This multilaboratory project is based on the analysis of a subcellular fraction from mouse liver that contains endoplasmic reticulum and other organelles. In this study, we present the strategy used for the preparation and initial characterization of the membrane sample, including validation that the carbonate-washing step enriches for integral and lipid-anchored membrane proteins. Analysis of 17 independent data sets from five types of proteomic workflows is in progress.
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Assessing the binding selectivity of molecularly imprinted polymer artificial antibodies by mass spectrometry-based profiling system.
J Biomed Mater Res A
PUBLISHED: 10-03-2009
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Molecularly imprinted polymer (MIP) is a technique for generating polymer-bearing biomimetic receptors. It offers several advantages to the research such as analysis, sensors, extraction, or preconcentration of components. Myoglobin is known to be an important biological index for the diagnosis of cardiac diseases. The purpose of this research was to optimize the formation of myoglobin-imprinted polymer (Myo-MIP) and develop a mass spectrometry-based profiling system for assessing the binding selectivity of artificial antibodies formed by Myo-MIP. Experimental results showed that myoglobin and albumin were bound/absorbed onto Myo-MIP chips and not to nonimprinted polymer (NIP) chips. Other proteins, such as histidine-rich glycoprotein, immunoglobulins, proapolipoprotein, and leech-derived tryptase inhibitor, were also observed but with less reproducibility from the chips.
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Study of human neutrophil peptides in saliva by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry.
Rapid Commun. Mass Spectrom.
PUBLISHED: 09-01-2009
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Matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry is used to rapidly characterize the human neutrophil peptides - HNP 1, 2, and 3 - in saliva. The saliva excreted from the parotid and sublingual/submandibular glands of 70 individuals were collected and examined using MALDI-TOF. The MALDI approach requires no sample pretreatment other than mixing the saliva-absorbing material with the matrix and drying under ambient conditions. Tissue paper was the best material for collecting the saliva samples because of its strong texture and high absorbance, and sinapinic acid was the best MALDI matrix for the analysis of the HNPs. HNPs were detected in almost all the samples collected from the parotid glands, with no obvious differences among age or gender. In contrast, the distribution of the HNPs in the samples collected from the sublingual/submandibular glands was age-dependent: no HNPs were detected for those collected from individuals younger than 30, but the HNPs were present in all of the samples collected from those older than 60 years. The increased probability of detecting saliva HNPs with age suggests that HNPs may function as a biomarker for aging.
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Novel virus-associated proteins encoded by UL112-113 of human cytomegalovirus.
J. Gen. Virol.
PUBLISHED: 08-05-2009
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Evidence suggests that the products of the human cytomegalovirus (HCMV) UL112-113 genes are involved in viral DNA replication during lytic infection. A polyclonal antibody was raised against the UL112 open reading frame (ORF) to characterize its function in detail. Immunoblots utilizing the UL112 antibody identified seven distinct protein bands (p20, p26, p28, p34, p43, p50 and p84) expressed during the HCMV infectious cycle. After screening a cDNA library constructed from cells 72 h after infection with HCMV, only four different cDNA protein-producing constructs were obtained, and their ORFs corresponded to p34, p43, p50 and p84. The proteins p20, p26 and p28 were further shown to be selectively included within mature HCMV particles, virions, non-infectious enveloped particles and dense bodies. Immunoaffinity protein purification was used to prepare the samples for liquid chromatography coupled to tandem mass spectrometry. This analysis revealed that p20, p26 and p28 were derived from the UL112 ORF, most likely through post-translational proteolytic cleavage.
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Deriving fast setting properties of tetracalcium phosphate/dicalcium phosphate anhydrous bone cement with nanocrystallites on the reactant surfaces.
J Dent
PUBLISHED: 06-05-2009
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This study attempts to reveal how nanocrystallites on the ceramic surfaces of non-dispersive calcium phosphate cement (nd-CPC) participate in setting processes as compared with conventional CPC (c-CPC).
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Melamine contamination.
Anal Bioanal Chem
PUBLISHED: 05-24-2009
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In the summer of 2008, serious illnesses and deaths of babies in China were linked to melamine-tainted powdered infant formula. Melamine contains several metabolites, such as ammeline, ammelide, and cyanuric acid, and has been used for the adulteration of foods or milk to increase their apparent protein content. It is assumed that melamine and its metabolites are absorbed in the gastrointestinal tract, and precipitate in the kidney to form crystals. A new tolerable daily intake of 0.2 mg kg(-1) body weight was adapted by the World Health Organization in 2008. This paper reviews the variety of analytical methods that have been used for the analysis of melamine in food. The limit of detection of these various methods is 0.05-100 ppm. The maximum acceptable concentration in food has been set at 50 ppb by the US FDA. A fast and ultrasensitive procedure for screening, detection, and characterization of melamine and its derivative compounds needs to be established. Currently, mass-spectrometry technologies provide an alternative to derivatization for regulatory analysis of food.
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Sustained release of 5-FU from Poloxamer gels interpenetrated by crosslinking chitosan network.
Int J Pharm
PUBLISHED: 05-07-2009
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This study investigates in vitro the drug delivery characteristics of new thermo-sensitive gels, P-CS/GA gels, in which a chitosan (CS) network is crosslinked with various concentrations of glutaraldehyde (GA) that interpenetrates Poloxamer (P) gels. The results indicate that the swelling ratios of all P-CS/GA gels are markedly superior to those of non-swelling P and P-CS gels. For example, P-CS/GA (0.1 wt.%) gels have swelling ratios of 13.2+/-1.0, which are maintained for approximately 18 h in water at 37 degrees C. In vitro releases of 5-FU from P-CS/GA (0.1 wt.%) gels had significantly lower initial burst release (P<0.01) and lasted much longer than those from gels without a CS network. For example, the duration of release of 5-FU was in a significantly sustained manner for up to 52 h, which was about 10 times or longer than the period of delivery using P or P-CS gels. The release of drugs from gels with an interpenetrating CS network could be modeled by Fickian diffusion; the characteristic constant k of drug-gel systems decreased as increasing GA concentrations in the P-CS/GA gels, and increasing the viscosities of the P, P-CS and P-CS/GA solutions.
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Use of apparent diffusion coefficients in evaluating the response of vestibular schwannomas to Gamma Knife surgery.
J. Neurosurg.
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Cellular density is a major factor responsible for changes in apparent diffusion coefficients (ADCs). The authors hypothesized that loss of tumor cells after Gamma Knife surgery (GKS) might alter ADC values. Magnetic resonance imaging, including diffusion-weighted (DW) imaging, was performed to detect cellular changes in brain tumors so that the authors could evaluate the tumor response to GKS as well as the efficacy of the procedure.
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Assessing human urinary proteome using a mass spectrometry-based profiling system combined with magnetic nanoparticles.
Clin. Chim. Acta
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Samples originating from body fluids often contain a complex mixture of inorganic salts, buffers, chaotropic agents, surfactant/detergents, preservatives, and other solubilizing agents. The presence of those contaminants often precludes direct analysis by mass spectrometry. Urine, a blood filtrate produced by the urinary system, is an ideal bio-sample and a rich source of biomarkers for diagnostic information.
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Utilizing isotope dilution-matrix-assisted laser desorption ionization-time of flight mass spectrometry as a reference procedure for the radioimmunoassay of serum thyroxine.
Clin. Chim. Acta
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The thyroid hormone, thyroxine (T4), is a tyrosine-based hormone produced by the thyroid gland, which is essential in regulating a number of biological processes, including growth, neurodevelopment, carbohydrate metabolism, oxygen consumption and protein synthesis. Data on human thyroid hormone metabolism were gathered since the middle of the 1970s mainly by the use of radioactive iodinated ((125)I or (131)I) hormones.
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A comparative proteomics analysis of peritoneal dialysate before and after the occurrence of peritonitis episode by mass spectrometry.
Clin. Chim. Acta
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Peritoneal dialysis (PD) is one of the therapeutic options for the end-stage renal disease (ESRD) patients. The peritoneal membrane is immersed in a high glucose concentration of the peritoneal dialysate, which may cause structural and functional damage. Peritonitis is one of the major complications of PD, which will accelerate the damage of peritoneal membrane by increasing the peritoneal permeability and decrease the ultrafiltration efficiency. It will cause the peritoneal membrane dysfunction and the patient may have fluid overload related complications or hemodialysis.
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Determining early adhesion of cells on polysaccharides/PCL surfaces by a quartz crystal microbalance.
J Mater Sci Mater Med
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The early adhesions of cells to various biopolymers are important to their growths and proliferations. Here, the adhesion of cells (e.g., fibroblasts) on the electrode of a quartz crystal microbalance (QCM) that was coated by PCL or PEG/PCL and further adsorbed by chitosan (CS) or CS/hyaluronic acid (HA) layers, was examined by cell-counting technique, QCM method and MTS assay under a serum-free condition for 3 h. The surfaces on electrodes of the QCM were confirmed to have been modified by measuring their contact angles, FT-IR spectra and the weights of biopolymers affected the frequency shifts of the QCM. Among tested surfaces on electrodes, the adhesion of fibroblasts on a HA/CS/PCL surface was the most (e.g., 3.08 × 10(5) cells/cm(2)) while that on a PEG/PCL surface was the least (e.g., 0.7 × 10(5) cells/cm(2)), as determined by cell-counting technique. The frequency shift and the mass of adhering fibroblasts on HA/CS/PCL electrodes were -3,537 ± 770 Hz and 3.78 ± 0.22 ?g (n = 3), respectively, that were significantly exceeded those on other electrodes (-393 ± 58 Hz and 0.32 ± 0.06 ?g, n = 3, respectively, for PEG/PCL electrodes). These results were consistent with cell-counting technique. Although MTS assay yielded similar results, it was less sensitive than the two aforementioned methods. In conclusion, modified electrodes of a QCM provide a convenient and sensitive method for examining the early adhesion of cells (e.g., 3 h) to biopolymer surfaces.
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Assessing the responses of cellular proteins induced by hyaluronic acid-modified surfaces utilizing a mass spectrometry-based profiling system: over-expression of CD36, CD44, CDK9, and PP2A.
Analyst
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The cell responses to biopolymer surface at the early adhesion stages can be critical for cell survival. The purpose of this research was to assess formation of hyaluronic acid (HA) biopolymer surface, the fibroblasts were used as an experimental model to evaluate the responses of cellular proteins induced by biopolymer materials using a mass spectrometry-based profiling system. Surfaces were covered by multi-walled carbon nanotubes (CNT), chitosan (CS), and HA to increase the surface area, enhance the adhesion of biopolymer and promote the rate of cell proliferation. The amount of adhered fibroblasts on CNT/CS/HA electrodes of quartz crystal microbalance (QCM) were greatly exceeded those on other surfaces that were consistent with cell-count technique. Moreover, analyzing differential protein expressions of adhered fibroblasts on those biopolymer surfaces by proteomic approaches identified CD36, CD44, PP2A, and CDK9 as key proteins. To validate the influences of those four proteins on adhesions of fibroblasts on biopolymers, the cells were blocked by antibodies of the proteins and the adhesions of cells on the tested biopolymer surfaces were examined using a QCM technique, flow cytometric analysis and morphological observations. The results of significantly decreasing the weights and densities of the blocked fibroblasts adhering to CNT/CS/HA surfaces were obtained, and validate those proteins found by proteomic approaches. Utilizing mass spectrometry-based proteomics to evaluate cell adhesions on biopolymers is proposed.
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Activity-dependent neuroprotector homeobox protein: A candidate protein identified in serum as diagnostic biomarker for Alzheimers disease.
J Proteomics
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Alzheimers disease (AD) is the most common cause of dementia of late life. To enhance our understanding of AD proteome, the serum proteins were analyzed using two-dimensional gel electrophoresis (2DE) combined with nano-high performance liquid chromatography electrospray ionization tandem mass spectrometry (nano-HPLC-ESI-MS/MS) followed by peptide fragmentation patterning. In this study, six protein spots with differential expression were identified. Five up-regulated proteins were identified as actin, apolipoprotein A-IV (Apo A-IV), inter-alpha-trypsin inhibitor heavy chain H4 (ITIH4), alpha-1-antitrypsin (AAT), and antithrombin-III (AT-III); one protein, activity-dependent neuroprotector homeobox protein (ADNP) was down-regulated in AD patients. These proteins with differential expression in the serum may serve as potential indicators of AD. Our results suggested that ADNP may play an important role in slowing the progression of clinical symptoms of AD.
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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.