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Find video protocols related to scientific articles indexed in Pubmed.
Chemical Modifications of Therapeutic Proteins Induced by Residual Ethylene Oxide.
J Pharm Sci
PUBLISHED: 09-10-2014
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Ethylene oxide (EtO) is widely used in sterilization of drug product primary containers and medical devices. The impact of residual EtO on protein therapeutics is of significant interest in the biopharmaceutical industry. The potential for EtO to modify individual amino acids in proteins has been previously reported. However, specific identification of EtO adducts in proteins and the effect of residual EtO on the stability of therapeutic proteins has not been reported to date. This paper describes studies of residual EtO with two therapeutic proteins, a PEGylated form of the recombinant human granulocyte colony-stimulating factor (Peg-GCSF) and recombinant human erythropoietin (EPO) formulated with human serum albumin (HSA). Peg-GCSF was filled in an EtO sterilized delivery device and incubated at accelerated stress conditions. Glu-C peptide mapping and LC-MS analyses revealed residual EtO reacted with Peg-GCSF and resulted in EtO modifications at two methionine residues (Met-127 and Met-138). In addition, tryptic peptide mapping and LC-MS analyses revealed residual EtO in plastic vials reacted with HSA in EPO formulation at Met-328 and Cys-34. This paper details the work conducted to understand the effects of residual EtO on the chemical stability of protein therapeutics. © 2014 Wiley Periodicals, Inc. and the American Pharmacists Association J Pharm Sci.
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Proteomics analysis of altered cellular metabolism induced by insufficient copper level.
J. Biotechnol.
PUBLISHED: 08-20-2014
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Insufficient copper level in the mammalian cell culture medium resulted in lactate accumulation while maintaining similar growth and culture viability profiles. Label-free, LC-MS/MS-based shotgun proteomics method was applied to compare the protein expression profiles obtained from the cultures exposed to suboptimal copper level to those provided with sufficient amount of copper. Under copper deficient condition, a substantial reduction of the protein levels of the multiple subunits of Complex IV, also known as cytochrome c oxidase, of the mitochondrial electron transport chain was observed for all three different Chinese Hamster Ovary (CHO) cell lines expressing therapeutic monoclonal antibodies tested. Additional proteins affected by suboptimal copper level included peroxiredoxin (PRDX) and hepatocyte-derived growth factor (HDGF), which were affected during early phase of the fed-batch production, several days prior to initiation of lactate accumulation. In contrast, proteins such as syntenin (SDCBP) and integral membrane 2C (ITM2C) showed altered expression patterns toward the end of culture duration, after lactate divergence had occurred. For all conditions tested, time was the most predominant factor facilitating the direction of global protein expression trend, with substantial number of proteins subjected to time-dependent changes in expression, independent of copper.
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[Prevention and management of complications after laparoscopic gastric bypass operation].
Zhonghua Wei Chang Wai Ke Za Zhi
PUBLISHED: 07-30-2014
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To investigate the prevention and management of complications after laparoscopic gastric bypass (LRYGB) operation.
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Acculturation and perceived stress in HIV+ immigrants: depression symptomatology in Asian and Pacific Islanders.
AIDS Care
PUBLISHED: 07-25-2014
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Asians and Pacific Islanders (API) are among the fastest growing minority groups within the USA, and this growth has been accompanied by an increase in HIV incidence. Between 2000 and 2010, the API HIV infection rate increased from 4.5% to 8.7%; however, there is a paucity of HIV-related research for this group, and even less is known about the prevalence and correlates of antiretroviral therapy adherence behavior, quality of life, impact of stress, and efficacious self-management among HIV+ API Americans. This paper examines how acculturation and perceived stress affect depression symptomatology and treatment seeking in the HIV+ API population. A series of cross-sectional audio computer-assisted self-interviews were conducted with a convenience sample of 50 HIV+ API (29 in San Francisco and 21 in New York City). The relationship between acculturation and perceived stress was analyzed, and the results indicate that for those HIV+ API who reported low or moderate acculturation (as compared to those who reported high acculturation), stress was significantly mediated by depression symptomology. Interventions to address acculturation and reduce perceived stress among API generally and Asians specifically are therefore needed.
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Laparoscopic Roux-en-Y Gastric Bypass for Type 2 Diabetes Mellitus in Nonobese Chinese Patients.
Surg Laparosc Endosc Percutan Tech
PUBLISHED: 07-24-2014
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Although bariatric surgery performed for morbid obesity has been shown to significantly improve type 2 diabetes mellitus (T2DM), data on its effectiveness to improve T2DM in nonobese patients are scarce. The present pilot study evaluated the clinical effects of laparoscopic Roux-en-Y gastric bypass surgery (LRYGB) in Chinese T2DM patients with body mass index (BMI) ?27.5 kg/m.
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Indirect genetic effects underlie oxygen-limited thermal tolerance within a coastal population of chinook salmon.
Proc. Biol. Sci.
PUBLISHED: 07-11-2014
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With global temperatures projected to surpass the limits of thermal tolerance for many species, evaluating the heritable variation underlying thermal tolerance is critical for understanding the potential for adaptation to climate change. We examined the evolutionary potential of thermal tolerance within a population of chinook salmon (Oncorhynchus tshawytscha) by conducting a full-factorial breeding design and measuring the thermal performance of cardiac function and the critical thermal maximum (CTmax) of offspring from each family. Additive genetic variation in offspring phenotype was mostly negligible, although these direct genetic effects explained 53% of the variation in resting heart rate (fH). Conversely, maternal effects had a significant influence on resting fH, scope for fH, cardiac arrhythmia temperature and CTmax. These maternal effects were associated with egg size, as indicated by strong relationships between the mean egg diameter of mothers and offspring thermal tolerance. Because egg size can be highly heritable in chinook salmon, our finding indicates that the maternal effects of egg size constitute an indirect genetic effect contributing to thermal tolerance. Such indirect genetic effects could accelerate evolutionary responses to the selection imposed by rising temperatures and could contribute to the population-specific thermal tolerance that has recently been uncovered among Pacific salmon populations.
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Spatial coating inhomogeneity of highly reflective mirrors determined by cavity ringdown measurements.
Appl Opt
PUBLISHED: 06-13-2014
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The inhomogeneity of high-reflectivity mirror coatings is a potential error source in the application of the cavity ringdown technique. Here, the ringdown times for different transverse modes were recorded. Together with the observed spatial distribution of these modes the ringdown times can be used to approximately locate the position of coating defects. A simple model based on a weighted sum of Hermite-Gaussian mode functions is used to explain the experimental results.
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Quantitative NTCP pharmacophore and lack of association between DILI and NTCP Inhibition.
Eur J Pharm Sci
PUBLISHED: 06-10-2014
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The human sodium taurocholate cotransporting polypeptide (NTCP) is a hepatic bile acid transporter. Inhibition of NTCP uptake may potentially also prevent hepatitis B virus (HBV) infection. The first objective was to develop a quantitative pharmacophore for NTCP inhibition. Recent studies showed that hepatotoxic drugs could inhibit bile acid uptake into hepatocytes, without inhibiting canalicular efflux, and cause bile acid elevation in plasma. Hence, a second objective was to examine whether NTCP inhibition is associated with drug induced liver injury (DILI). Twenty-seven drugs from our previous study were used as the training set to develop a quantitative pharmacophore. From secondary screening from a drug database, six retrieved drugs and three drugs not retrieved by the model were tested for NTCP inhibition. Tertiary screening involved drugs known to cause DILI and not cause DILI. Overall, ninety-four drugs were assessed for hepatotoxicity and were assessed relative to NTCP inhibition. The quantitative pharmacophore possessed one hydrogen bond acceptor, one hydrogen bond donor, a hydrophobic feature, and excluded volumes. From 94 drugs, NTCP inhibitors and non-inhibitors were approximately equally distributed across the drugs of most DILI concern, less DILI concern, and no DILI concern, indicating no relationship between NTCP inhibition and DILI risk. Hence, an approach to treat HBV via NTCP inhibition is not expected to be associated with DILI.
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Lipase immobilized catalytically active membrane for synthesis of lauryl stearate in a pervaporation membrane reactor.
Bioresour. Technol.
PUBLISHED: 05-21-2014
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A composite catalytically active membrane immobilized with Candida rugosa lipase has been prepared by immersion phase inversion technique for enzymatic synthesis of lauryl stearate in a pervaporation membrane reactor. SEM images showed that a "sandwich-like" membrane structure with a porous lipase-PVA catalytic layer uniformly coated on a polyvinyl alcohol (PVA)/polyethersulfone (PES) bilayer was obtained. Optimum conditions for lipase immobilization in the catalytic layer were determined. The membrane was proved to exhibit superior thermal stability, pH stability and reusability than free lipase under similar conditions. In the case of pervaporation coupled synthesis of lauryl stearate, benefited from in-situ water removal by the membrane, a conversion enhancement of approximately 40% was achieved in comparison to the equilibrium conversion obtained in batch reactors. In addition to conversion enhancement, it was also found that excess water removal by the catalytically active membrane appears to improve activity of the lipase immobilized.
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Immobilization of lipase on porous monodisperse chitosan microspheres.
Biotechnol. Appl. Biochem.
PUBLISHED: 05-07-2014
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Porous monodisperse chitosan microspheres were synthesized for enzyme immobilization. The microspheres were prepared using microchannels and modified with glutaraldehyde. The microspheres had a mean diameter of 495 µm; the polydispersity indices were less than 0.08, and the specific surface area was between 121 and 173 m(2) /g. Candida sp. 1619 lipase was selected as a model lipase. Immobilization conditions such as enzyme loading, glutaraldehyde concentration, and immobilization time were optimized. The temperature, pH, and storage stability of the free and immobilized enzymes were also investigated. The immobilized enzyme had broad-ranging pH and temperature optima as compared with free enzyme. The storage stability of the immobilized enzyme was higher than that of the free enzyme.
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Identification of a mosquitocidal toxin from Bacillus thuringiensis using mass spectrometry.
World J. Microbiol. Biotechnol.
PUBLISHED: 05-05-2014
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The Bacillus thuringiensis strain S2160-1 has previously been identified as being highly toxic to mosquito larvae and a viable alternative to strains currently used commercially to control these insects. A PCR approach had identified the presence of four putative insecticidal toxin genes (cry30Ea, cry30 Ga, cry50Ba and cry54Ba) in this strain, but did not identify the genes that encoding three of the main crystal toxin proteins of size 140 and 130 and 30 kDa. In this study we used mass spectrometry to identify the 130 kDa toxin as a rare Cry4 toxin (Cry4Cb3). The gene encoding this toxin was cloned and expressed and the toxin shown to have mosquitocidal activity against Culex quinquefasciatus.
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Discovery and characterization of a photo-oxidative histidine-histidine cross-link in IgG1 antibody utilizing ¹?O-labeling and mass spectrometry.
Anal. Chem.
PUBLISHED: 05-02-2014
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A novel photo-oxidative cross-linking between two histidines (His-His) has been discovered and characterized in an IgG1 antibody via the workflow of XChem-Finder, (18)O labeling and mass spectrometry (Anal. Chem. 2013, 85, 5900-5908). Its structure was elucidated by peptide mapping with multiple proteases with various specificities (e.g., trypsin, Asp-N, and GluC combined with trypsin or Asp-N) and mass spectrometry with complementary fragmentation modes (e.g., collision-induced dissociation (CID) and electron-transfer dissociation (ETD)). Our data indicated that cross-linking occurred across two identical conserved histidine residues on two separate heavy chains in the hinge region, which is highly flexible and solvent accessible. On the basis of model studies with short peptides, it has been proposed that singlet oxygen reacts with the histidyl imidazole ring to form an endoperoxide and then converted to the 2-oxo-histidine (2-oxo-His) and His+32 intermediates, the latter is subject to a nucleophilic attack by the unmodified histidine; and finally, elimination of a water molecule leads to the final adduct with a net mass increase of 14 Da. Our findings are consistent with this mechanism. Successful discovery of cross-linked His-His again demonstrates the broad applicability and utility of our XChem-Finder approach in the discovery and elucidation of protein cross-linking, particularly without a priori knowledge of the chemical nature and site of cross-linking.
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Biochars derived from various crop straws: characterization and Cd(II) removal potential.
Ecotoxicol. Environ. Saf.
PUBLISHED: 04-29-2014
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Five types of biochars prepared from four crop straws and one wood shaving at 600 °C were characterized, and their sorption to Cd(II) were determined to investigate the differences in capacity to function as sorbents to heavy metals. Surface areas and pore volumes of the biochars were inversely correlated to the lignin content of raw biomass. The biochars derived from crop straws displayed more developed pore structure than wood char due to the higher lignin content of wood. Sorption capacity of the biochars to Cd(II) followed the order of corn straw>cotton straw>wheat straw>rice straw>poplar shaving, which was not strictly consistent with the surface area of the chars. The surface characteristics of chars before and after Cd(II) sorption were investigated with scanning electron microscopy equipped with an energy dispersive X-ray spectroscopy and Fourier transform infrared spectroscopy, which suggested that the higher sorption of Cd(II) on corn straw chars was mainly attributed to cation exchange, surface precipitation of carbonate, and surface complexation with oxygen-containing groups. This study indicated that crop straw biochars exhibit distinct sorption capacities to heavy metals due to various surface characteristics, and thus the sorption efficiency should be carefully evaluated specific to target contaminant.
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Non-invasive prediction of hemoglobin levels by principal component and back propagation artificial neural network.
Biomed Opt Express
PUBLISHED: 04-01-2014
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To facilitate non-invasive diagnosis of anemia, specific equipment was developed, and non-invasive hemoglobin (HB) detection method based on back propagation artificial neural network (BP-ANN) was studied. In this paper, we combined a broadband light source composed of 9 LEDs with grating spectrograph and Si photodiode array, and then developed a high-performance spectrophotometric system. By using this equipment, fingertip spectra of 109 volunteers were measured. In order to deduct the interference of redundant data, principal component analysis (PCA) was applied to reduce the dimensionality of collected spectra. Then the principal components of the spectra were taken as input of BP-ANN model. On this basis we obtained the optimal network structure, in which node numbers of input layer, hidden layer, and output layer was 9, 11, and 1. Calibration and correction sample sets were used for analyzing the accuracy of non-invasive hemoglobin measurement, and prediction sample set was used for testing the adaptability of the model. The correlation coefficient of network model established by this method is 0.94, standard error of calibration, correction, and prediction are 11.29g/L, 11.47g/L, and 11.01g/L respectively. The result proves that there exist good correlations between spectra of three sample sets and actual hemoglobin level, and the model has a good robustness. It is indicated that the developed spectrophotometric system has potential for the non-invasive detection of HB levels with the method of BP-ANN combined with PCA.
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Adoptive transfer of MART-1 T-cell receptor transgenic lymphocytes and dendritic cell vaccination in patients with metastatic melanoma.
Clin. Cancer Res.
PUBLISHED: 03-14-2014
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It has been demonstrated that large numbers of tumor-specific T cells for adoptive cell transfer (ACT) can be manufactured by retroviral genetic engineering of autologous peripheral blood lymphocytes and expanding them over several weeks. In mouse models, this therapy is optimized when administered with dendritic cell (DC) vaccination. We developed a short 1-week manufacture protocol to determine the feasibility, safety, and antitumor efficacy of this double cell therapy.
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Neural stem cells improve intracranial nanoparticle retention and tumor-selective distribution.
Future Oncol
PUBLISHED: 02-25-2014
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The purpose of this work is to determine if tumor-tropic neural stem cells (NSCs) can improve the tumor-selective distribution and retention of nanoparticles (NPs) within invasive brain tumors.
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Pressure-assisted electrokinetic injection stacking for verteporfin drug to achieve highly sensitive enantioseparation and detection in artificial urine by capillary electrophoresis.
J Chromatogr A
PUBLISHED: 02-06-2014
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Pressure-assisted electrokinetic injection (PAEKI) was applied for negatively charged verteporfin (VER) overloading and inline stacking, which targeted highly sensitive enantioseparation by CE. The essential step of PAEKI is a constant pressure used to counterbalance the electroosmotic flow (EOF), consequently, the large amount of analyte could be permitted into capillary and concentrated at the motionless boundary of the sample zone and background electrolyte (BGE). Aiming to know the balance, the velocity of the whole BGE in capillary by the impetus of pressure (0.2-2.0psi), and the velocity of EOF depending on the length of sample plug and voltage (5.0-20kV) was investigated, respectively. The velocity of bulk flow in capillary has good linearity with the pressure or applied voltage. Through the pattern of EOF marked peak and analyte peaks (dissolved in pure water), the constant pressure (0.8psi) vs. the added voltage (-10.3kV) during PAEKI was confirmed to immobilize the bulk flow of BGE, thus the sample injection time could sustain 2.0min without compromising separation efficiency. The obtained LOD (S/N=3) of each isomer at UV detection (428nm) was around 10.3?g/L, which was improved to 116 and 39-fold in comparison with normal hydrodynamic injection (HDI) and electrokinetic injection (EKI). The LOD is far below the reported value with LIF detection of VER. The RSD (n=5) of migration time and peak area was, respectively, around 3.5% and 5.7% for the proposed PAEKI method. Finally, PAEKI was used for the detection of VER in artificial urine to investigate the matrix interference.
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Giant appendiceal neurofibroma in von Recklinghausen's disease: A case report and literature review.
Oncol Lett
PUBLISHED: 01-22-2014
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A 62-year-old female with neurofibromatosis type 1 (NF1; also von Recklinghausen's disease) was diagnosed with a giant, thick-walled tubular mass, mainly located in the right abdominal area on computed tomography, following an examination for intermittent abdominal pain and increasing abdominal distension. According to the clinical manifestations and imaging features, the giant tubular mass was considered most likely to be a dilated fallopian tube associated with infection, while the possibility of obstructed bowel loops was excluded. However, the subsequent laparotomy revealed a giant appendix, caused by a large neurofibroma in the root region of the appendix, which occluded the lumen. Neurofibroma of the appendix is extremely rare, even in patients with NF1. To the best of our knowledge, only three such cases have previously been reported in the English literature to date.
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LC-MS/MS peptide mapping with automated data processing for routine profiling of N-glycans in immunoglobulins.
J. Am. Soc. Mass Spectrom.
PUBLISHED: 01-06-2014
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Protein N-Glycan analysis is traditionally performed by high pH anion exchange chromatography (HPAEC), reversed phase liquid chromatography (RPLC), or hydrophilic interaction liquid chromatography (HILIC) on fluorescence-labeled glycans enzymatically released from the glycoprotein. These methods require time-consuming sample preparations and do not provide site-specific glycosylation information. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) peptide mapping is frequently used for protein structural characterization and, as a bonus, can potentially provide glycan profile on each individual glycosylation site. In this work, a recently developed glycopeptide fragmentation model was used for automated identification, based on their MS/MS, of N-glycopeptides from proteolytic digestion of monoclonal antibodies (mAbs). Experimental conditions were optimized to achieve accurate profiling of glycoforms. Glycan profiles obtained from LC-MS/MS peptide mapping were compared with those obtained from HPAEC, RPLC, and HILIC analyses of released glycans for several mAb molecules. Accuracy, reproducibility, and linearity of the LC-MS/MS peptide mapping method for glycan profiling were evaluated. The LC-MS/MS peptide mapping method with fully automated data analysis requires less sample preparation, provides site-specific information, and may serve as an alternative method for routine profiling of N-glycans on immunoglobulins as well as other glycoproteins with simple N-glycans.
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The impact of pri-miR-218 rs11134527 on the risk and prognosis of patients with esophageal squamous cell carcinoma.
Int J Clin Exp Pathol
PUBLISHED: 01-01-2014
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MicroRNA-218 (miR-218) acts as a tumor suppressor in numerous types of cancer by regulation of the expression of target genes. The aim of this study was to investigate whether polymorphisms in miR-218 LAMB3 pathway were associated with the risk and prognosis of esophageal squamous cell carcinoma (ESCC). Pri-mir-218 rs11134527 and LAMB3 rs2566 were genotyped in ESCC patients and 745 controls to assess their associations with cancer risk and overall survival. Pri-mir-218 rs11134527 was significantly associated with a decreased risk of ESCC under codominant, recessive and additive models. Although there was a significant association between rs11134527 and better survival of ESCC patients under codominant, recessive and additive models, the association disappeared after adjustment for TNM and LNM. However, further stratified analysis revealed that the association remained significant in patients with TNM stages I and II or non-LNM. Our data suggest that pri-miR-218 rs11134527 may contribute to the genetic susceptibility and prognosis for ESCC in Chinese Han population.
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Risk factors for long-term outcome of drug-eluting stenting in adults with early-onset coronary artery disease.
Int J Med Sci
PUBLISHED: 01-01-2014
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We lack data on the long-term outcome of drug-eluting stenting in patients with early-onset coronary artery disease (CAD). Here, we investigated the association of traditional risk factors and major adverse cardiovascular events (MACEs) after drug-eluting stenting in patients with CAD who were < 50 years old.
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Association between low serum magnesium level and major adverse cardiac events in patients treated with drug-eluting stents for acute myocardial infarction.
PLoS ONE
PUBLISHED: 01-01-2014
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We investigated the association of serum magnesium (Mg) levels and major adverse cardiac events (MACEs) after drug-eluting stent (DES) implantation.
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G/U and certain wobble position mismatches as possible main causes of amino acid misincorporations.
Biochemistry
PUBLISHED: 10-31-2013
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A mass spectrometry-based method was developed to measure amino acid substitutions directly in proteins down to a level of 0.001%. When applied to recombinant proteins expressed in Escherichia coli, monoclonal antibodies expressed in mammalian cells, and human serum albumin purified from three human subjects, the method revealed a large number of amino acid misincorporations at levels of 0.001-0.1%. The detected misincorporations were not random but involved a single-base difference between the codons of the corresponding amino acids. The most frequent base differences included a change from G to A, corresponding to a G(mRNA)/U(tRNA) base pair mismatch during translation. We concluded that under balanced nutrients, G(mRNA)/U(tRNA) mismatches at any of the three codon positions and certain additional wobble position mismatches (C/U and/or U/U) are the main causes of amino acid misincorporations. The hypothesis was tested experimentally by monitoring the levels of misincorporation at several amino acid sites encoded by different codons, when a protein with the same amino acid sequence was expressed in E. coli using 13 different DNA sequences. The observed levels of misincorporation were different for different codons and agreed with the predicted levels. Other less frequent misincorporations may occur due to G(DNA)/U(mRNA) mismatch during transcription, mRNA editing, U(mRNA)/G(tRNA) mismatch during translation, and tRNA mischarging.
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An energy efficient stable election-based routing algorithm for wireless sensor networks.
Sensors (Basel)
PUBLISHED: 09-09-2013
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Sensor nodes usually have limited energy supply and they are impractical to recharge. How to balance traffic load in sensors in order to increase network lifetime is a very challenging research issue. Many clustering algorithms have been proposed recently for wireless sensor networks (WSNs). However, sensor networks with one fixed sink node often suffer from a hot spots problem since nodes near sinks have more traffic burden to forward during a multi-hop transmission process. The use of mobile sinks has been shown to be an effective technique to enhance network performance features such as latency, energy efficiency, network lifetime, etc. In this paper, a modified Stable Election Protocol (SEP), which employs a mobile sink, has been proposed for WSNs with non-uniform node distribution. The decision of selecting cluster heads by the sink is based on the minimization of the associated additional energy and residual energy at each node. Besides, the cluster head selects the shortest path to reach the sink between the direct approach and the indirect approach with the use of the nearest cluster head. Simulation results demonstrate that our algorithm has better performance than traditional routing algorithms, such as LEACH and SEP.
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DNA aggregation and cleavage in CGE induced by high electric field in aqueous solution accompanying electrokinetic sample injection.
Electrophoresis
PUBLISHED: 08-02-2013
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The phenomenon of peak area decrease due to high injection voltage (Vinj , e.g. 10-30 kV, 200-600 V/cm in the 50 cm capillary) was found in the analysis of very dilute DNA fragments (<0.2 mg/L) by using high-sensitive electrokinetic supercharging-CGE. The possibility of DNA cleavage in aqueous solution was suggested, in addition to the aggregation phenomenon that is already known. The analysis of intentionally voltage-affected fragments (at 200 V/cm) also showed decreased peak areas depending on the time of the voltage being applied. Computer simulation suggested that a high electric field (a few kV/cm or more) could be generated partly between the electrode and the capillary end during electrokinetic injection (EKI) process. After thorough experimental verification, it was found that the factors affecting the damage during EKI were the magnitude of electric field, the distance between tips of electrode and capillary (De/c ), sample concentration and traveling time during EKI in sample vials. Furthermore, these factors are correlating with each other. A low conductivity of diluted sample would cause a high electric field (over a few hundred volts per centimeter), while the longer De/c results in a longer traveling time during EKI, which may cause a larger degree of damage (aggregation and cleavage) on the DNA fragments. As an important practical implication of this study, when the dilute DNA fragments (sub mg/L) are to be analyzed by CGE using EKI, injection voltage should be kept as low as possible.
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Effects of prophylactic and therapeutic teriflunomide in transcranial magnetic stimulation-induced motor-evoked potentials in the dark agouti rat model of experimental autoimmune encephalomyelitis.
J. Pharmacol. Exp. Ther.
PUBLISHED: 07-26-2013
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Teriflunomide is a once-daily oral immunomodulatory agent recently approved in the United States for the treatment of relapsing multiple sclerosis (RMS). This study investigated neurophysiological deficits in descending spinal cord motor tracts during experimental autoimmune encephalomyelitis (EAE; a model of multiple sclerosis) and the functional effectiveness of prophylactic or therapeutic teriflunomide treatment in preventing the debilitating paralysis observed in this model. Relapsing-remitting EAE was induced in Dark Agouti rats using rat spinal cord homogenate. Animals were treated with oral teriflunomide (10 mg/kg daily) prophylactically, therapeutically, or with vehicle (control). Transcranial magnetic motor-evoked potentials were measured throughout the disease to provide quantitative assessment of the neurophysiological status of descending motor tracts. Axonal damage was quantified histologically by silver staining. Both prophylactic and therapeutic teriflunomide treatment significantly reduced maximum EAE disease scores (P < 0.0001 and P = 0.0001, respectively) compared with vehicle-treated rats. Electrophysiological recordings demonstrated that both teriflunomide treatment regimens prevented a delay in wave-form latency and a decrease in wave-form amplitude compared with that observed in vehicle-treated animals. A significant reduction in axonal loss was observed with both teriflunomide treatment regimens compared with vehicle (P < 0.0001 and P = 0.0014, respectively). The results of this study suggest that therapeutic teriflunomide can prevent the deficits observed in this animal model in descending spinal cord motor tracts. The mechanism behind reduced axonal loss and improved motor function may be primarily the reduced inflammation and consequent demyelination observed in these animals through the known effects of teriflunomide on impairing proliferation of stimulated T cells. These findings may have significant implications for patients with RMS.
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Association between TLR4 polymorphism and periodontitis susceptibility: a meta-analysis.
Crit. Rev. Eukaryot. Gene Expr.
PUBLISHED: 07-25-2013
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TLR4 has been implicated in periodontal disease, but the association between the TLR4 Asp299Gly and Thr399Ile polymorphisms and the risk of periodontal disease remains unclear. Therefore, the aim of this study was to investigate the association between the TLR4 Asp299Gly and Thr399Ile polymorphism and periodontal disease. A search of electronic databases identified previous studies evaluating the association of the polymorphisms of TLR4 and periodontitis risk. The association was evaluated by odds ratio (OR) and its 95% confidence interval (CI). The results showed that TLR4 Asp299Gly and Thr399Ile were not associated with a significant risk of periodontitis (OR = 0.96, 95% CI = 0.80-1.16 for G versus A; OR = 1.39, 95% CI = 0.82-2.36 for AG/GG versus AA; OR = 1.05, 95% CI = 0.52-2.15 for T versus C; OR = 0.76, 95% CI = 0.55-1.04 for CT/TT versus CC). In the stratified analyses, there was no significantly increased risk for the studies of chronic periodontitis and aggressive periodontitis. Our meta-analysis revealed that the two common TLR4 polymorphisms, Asp299Gly and Thr399Ile, have no association with the likelihood of periodontitis. In a subgroup analysis by ethnicity and periodontitis type, the results also did not show any association. However, there was a significant increased risk for periodontitis in recessive models of Asp299Gly. The effect of genetic networks and their mutual interactions in the TLR4 signaling pathway on periodontitis susceptibility needs further study.
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Characterization of organic phosphorus in lake sediments by sequential fractionation and enzymatic hydrolysis.
Environ. Sci. Technol.
PUBLISHED: 06-27-2013
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The role of sediment-bound organic phosphorus (Po) on lake eutrophication was studied using sequential extraction and enzymatic hydrolysis by collecting sediments from Dianchi Lake, China. Bioavailable Po species including labile monoester P, diester P, and phytate-like P were identified in the sequential extractions by H2O, NaHCO3, and NaOH. For the H2O-Po, 36.7% (average) was labile monoester P, 14.8% was diester P, and 69.9% was phytate-like P. In NaHCO3-Po, 19.9% was labile monoester P, 17.5% was diester P, and 58.8% was phytate-like P. For NaOH-Po, 25.6% was labile monoester P, 7.9% was diester P, and 35.9% was phytate-like P. Labile monoester P was active to support growth of algae to form blooms. Diester P mainly distributed in labile H2O and NaHCO3 fractions was readily available to cyanobacteria. Phytate-like P represents a major portion of the Po in the NaOH fractions, also in the more labile H2O and NaHCO3 fractions. Based on results of sequential extraction of Po and enzymatic hydrolysis, lability and bioavailability was in decreasing order as follows: H2O-Po > NaHCO3-Po > NaOH-Po, and bioavailable Po accounted for only 12.1-27.2% of total Po in sediments. These results suggest that the biogeochemical cycle of bioavailable Po might play an important role in maintaining the eutrophic status of lakes.
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Sites of acetylation on newly synthesized histone H4 are required for chromatin assembly and DNA damage response signaling.
Mol. Cell. Biol.
PUBLISHED: 06-17-2013
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The best-characterized acetylation of newly synthesized histone H4 is the diacetylation of the NH2-terminal tail on lysines 5 and 12. Despite its evolutionary conservation, this pattern of modification has not been shown to be essential for either viability or chromatin assembly in any model organism. We demonstrate that mutations in histone H4 lysines 5 and 12 in yeast confer hypersensitivity to replication stress and DNA-damaging agents when combined with mutations in histone H4 lysine 91, which has also been found to be a site of acetylation on soluble histone H4. In addition, these mutations confer a dramatic decrease in cell viability when combined with mutations in histone H3 lysine 56. We also show that mutation of the sites of acetylation on newly synthesized histone H4 results in defects in the reassembly of chromatin structure that accompanies the repair of HO-mediated double-strand breaks. This defect is not due to a decrease in the level of histone H3 lysine 56 acetylation. Intriguingly, mutations that alter the sites of newly synthesized histone H4 acetylation display a marked decrease in levels of phosphorylated H2A (?-H2AX) in chromatin surrounding the double-strand break. These results indicate that the sites of acetylation on newly synthesized histones H3 and H4 can function in nonoverlapping ways that are required for chromatin assembly, viability, and DNA damage response signaling.
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Ischemia/Reperfusion-Inducible Protein Modulates the Function of Organic Cation Transporter 1 and Multidrug and Toxin Extrusion 1.
Mol. Pharm.
PUBLISHED: 06-03-2013
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The recently identified ischemia/reperfusion-inducible protein (IRIP) has been reported to negatively modulate the activities of several transporters in cell culture systems. The goal of this study is to determine whether IRIP regulates the activities of OCT1 and MATE1, and hence the disposition in vivo of their substrate metformin, a therapeutic drug for diabetes and other obesity-related syndromes. In the uptake studies in the human embryonic kidney 293 cells overexpressing IRIP with and without OCT1 or MATE1, IRIP overexpression was found to significantly inhibit the uptake of 1-methyl-4-phenylpyridinium mediated by OCT1 or MATE1. In contrast, knockdown of IRIP by small hairpin RNA (shRNA) increased the transporter activities in vitro. IRIP overexpression decreased the membrane localization of transporter proteins without any changes in transcript levels in cells. By overexpressing IRIP in mouse liver via hydrodynamic tail vein injection, we demonstrated that increased IRIP expression could cause a significant reduction in hepatic accumulation of metformin (P < 0.01). In addition, we observed that the expression of IRIP was approximately half (P < 0.01) in ob/ob mice when compared to their lean littermates, with significant increases in hepatic Oct1 protein expression and metformin accumulation. In conclusion, IRIP negatively modulates the function of OCT1 and MATE1 in cells. Importantly, we provide in vivo evidence for such modulation that may cause an alteration in drug disposition. The regulation by IRIP on transporter activities likely occurs at a post-transcriptional level, and future studies are needed to characterize the exact mechanism.
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Histone acetyl transferase 1 is essential for mammalian development, genome stability, and the processing of newly synthesized histones H3 and H4.
PLoS Genet.
PUBLISHED: 06-01-2013
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Histone acetyltransferase 1 is an evolutionarily conserved type B histone acetyltransferase that is thought to be responsible for the diacetylation of newly synthesized histone H4 on lysines 5 and 12 during chromatin assembly. To understand the function of this enzyme in a complex organism, we have constructed a conditional mouse knockout model of Hat1. Murine Hat1 is essential for viability, as homozygous deletion of Hat1 results in neonatal lethality. The lungs of embryos and pups genetically deficient in Hat1 were much less mature upon histological evaluation. The neonatal lethality is due to severe defects in lung development that result in less aeration and respiratory distress. Many of the Hat1(-/-) neonates also display significant craniofacial defects with abnormalities in the bones of the skull and jaw. Hat1(-/-) mouse embryonic fibroblasts (MEFs) are defective in cell proliferation and are sensitive to DNA damaging agents. In addition, the Hat1(-/-) MEFs display a marked increase in genome instability. Analysis of histone dynamics at sites of replication-coupled chromatin assembly demonstrates that Hat1 is not only responsible for the acetylation of newly synthesized histone H4 but is also required to maintain the acetylation of histone H3 on lysines 9, 18, and 27 during replication-coupled chromatin assembly.
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Discovery of undefined protein cross-linking chemistry: a comprehensive methodology utilizing 18O-labeling and mass spectrometry.
Anal. Chem.
PUBLISHED: 05-28-2013
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Characterization of protein cross-linking, particularly without prior knowledge of the chemical nature and site of cross-linking, poses a significant challenge, because of their intrinsic structural complexity and the lack of a comprehensive analytical approach. Toward this end, we have developed a generally applicable workflow-XChem-Finder-that involves four stages: (1) detection of cross-linked peptides via (18)O-labeling at C-termini; (2) determination of the putative partial sequences of each cross-linked peptide pair using a fragment ion mass database search against known protein sequences coupled with a de novo sequence tag search; (3) extension to full sequences based on protease specificity, the unique combination of mass, and other constraints; and (4) deduction of cross-linking chemistry and site. The mass difference between the sum of two putative full-length peptides and the cross-linked peptide provides the formulas (elemental composition analysis) for the functional groups involved in each cross-linking. Combined with sequence restraint from MS/MS data, plausible cross-linking chemistry and site were inferred, and ultimately confirmed, by matching with all data. Applying our approach to a stressed IgG2 antibody, 10 cross-linked peptides were discovered and found to be connected via thioethers originating from disulfides at locations that had not been previously recognized. Furthermore, once the cross-link chemistry was revealed, a targeted cross-link search yielded 4 additional cross-linked peptides that all contain the C-terminus of the light chain.
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[A case of large foreign body in hypopharynx and upper esophagus].
Lin Chung Er Bi Yan Hou Tou Jing Wai Ke Za Zhi
PUBLISHED: 05-25-2013
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A case of large artificial teeth in hypopharynx and upper esophagus was reported. Physical signs of laryngeal obstruction were detected. CT showed foreign body in right pyriform sinus. Acute tracheotomy was performed before removal of the large foreign body with the help of esophagoscope and mouth-gag.
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Ondansetron can enhance cisplatin-induced nephrotoxicity via inhibition of multiple toxin and extrusion proteins (MATEs).
Toxicol. Appl. Pharmacol.
PUBLISHED: 05-14-2013
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The nephrotoxicity limits the clinical application of cisplatin. Human organic cation transporter 2 (OCT2) and multidrug and toxin extrusion proteins (MATEs) work in concert in the elimination of cationic drugs such as cisplatin from the kidney. We hypothesized that co-administration of ondansetron would have an effect on cisplatin nephrotoxicity by altering the function of cisplatin transporters. The inhibitory potencies of ondansetron on metformin accumulation mediated by OCT2 and MATEs were determined in the stable HEK-293 cells expressing these transporters. The effects of ondansetron on drug disposition in vivo were examined by conducting the pharmacokinetics of metformin, a classical substrate for OCTs and MATEs, in wild-type and Mate1-/- mice. The nephrotoxicity was assessed in the wild-type and Mate1-/- mice received cisplatin with and without ondansetron. Both MATEs, including human MATE1, human MATE2-K, and mouse Mate1, and OCT2 (human and mouse) were subject to ondansetron inhibition, with much greater potencies by ondansetron on MATEs. Ondansetron significantly increased tissue accumulation and pharmacokinetic exposure of metformin in wild-type but not in Mate1-/- mice. Moreover, ondansetron treatment significantly enhanced renal accumulation of cisplatin and cisplatin-induced nephrotoxicity which were indicated by increased levels of biochemical and molecular biomarkers and more severe pathohistological changes in mice. Similar increases in nephrotoxicity were caused by genetic deficiency of MATE function in mice. Therefore, the potent inhibition of MATEs by ondansetron enhances the nephrotoxicity associated with cisplatin treatment in mice. Potential nephrotoxic effects of combining the chemotherapeutic cisplatin and the antiemetic 5-hydroxytryptamine-3 (5-HT3) receptor antagonists, such as ondansetron, should be investigated in patients.
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Effect of lignocellulosic composition and structure on the bioethanol production from different poplar lines.
Bioresour. Technol.
PUBLISHED: 03-26-2013
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Branches from three transgenic poplar lines and their wild type line 107 were used to study the effect of lignocellulosic composition and structure on the production of glucose and ethanol. Experimental results showed that the transgenic line 18-1 had the high cellulose content and amorphous fibril structure. After poplar meals were pretreated with 10% NaOH and a mixture of hydrogen peroxide and acetic acid, their lateral order index decreased significantly. The highest glucose yield in enzymatic hydrolysis and ethanol yield from the substrate of 18-1 was much higher than that from feedstock of 107 by 192.7% and 108.7%, respectively. Scanning electron microscopy images confirmed that lignocellulose from the 18-1 could be destroyed by chemicals more easily than those from other lines. These results demonstrated that changing lignocellulose structure could be more effective on improving the digestibility and enzymatic hydrolysis of poplar biomass than increasing the cellulose content in biomass.
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Multifunctional T-cell analyses to study response and progression in adoptive cell transfer immunotherapy.
Cancer Discov
PUBLISHED: 03-21-2013
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Adoptive cell transfer (ACT) of genetically engineered T cells expressing cancer-specific T-cell receptors (TCR) is a promising cancer treatment. Here, we investigate the in vivo functional activity and dynamics of the transferred cells by analyzing samples from 3 representative patients with melanoma enrolled in a clinical trial of ACT with TCR transgenic T cells targeted against the melanosomal antigen MART-1. The analyses included evaluating 19 secreted proteins from individual cells from phenotypically defined T-cell subpopulations, as well as the enumeration of T cells with TCR antigen specificity for 36 melanoma antigens. These analyses revealed the coordinated functional dynamics of the adoptively transferred, as well as endogenous, T cells, and the importance of highly functional T cells in dominating the antitumor immune response. This study highlights the need to develop approaches to maintaining antitumor T-cell functionality with the aim of increasing the long-term efficacy of TCR-engineered ACT immunotherapy.
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Mechanistic understanding of tetracycline sorption on waste tire powder and its chars as affected by Cu(2+) and pH.
Environ. Pollut.
PUBLISHED: 02-19-2013
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The sorption characteristics of tetracycline (TC) by waste tire powder and its chars were investigated to explore the potential of using waste tires as effective sorbents for removal of TC from aqueous solution. Naphthalene (NAPH), a typical hydrophobic organic compound, was selected as asorbate for comparison. TC displayed much lower sorption affinity to tire powder than NAPH. However, it exhibited similar adsorption affinity as NAPH on the pyrolyzed tire chars, which was mainly attributed to ?-? electron-donor-acceptor interactions of TC with the graphite surface of chars. TC and Cu(2+) could mutually facilitate the sorption of each other on both tire powder and pyrolyzed chars in a wide pH range. This could be explained by the metallic complexation and/or surface-bridging mechanisms (i.e., Cu- or TC-bridging). However, Cu(2+) and NAPH depressed the sorption of each other on tire powder and displayed negligible impact to each other on the highly pyrolyzed chars.
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Structure-activity relationship for FDA approved drugs as inhibitors of the human sodium taurocholate cotransporting polypeptide (NTCP).
Mol. Pharm.
PUBLISHED: 02-12-2013
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The hepatic bile acid uptake transporter sodium taurocholate cotransporting polypeptide (NTCP) is less well characterized than its ileal paralog, the apical sodium dependent bile acid transporter (ASBT), in terms of drug inhibition requirements. The objectives of this study were (a) to identify FDA approved drugs that inhibit human NTCP, (b) to develop pharmacophore and Bayesian computational models for NTCP inhibition, and (c) to compare NTCP and ASBT transport inhibition requirements. A series of NTCP inhibition studies were performed using FDA approved drugs, in concert with iterative computational model development. Screening studies identified 27 drugs as novel NTCP inhibitors, including irbesartan (Ki = 11.9 ?M) and ezetimibe (Ki = 25.0 ?M). The common feature pharmacophore indicated that two hydrophobes and one hydrogen bond acceptor were important for inhibition of NTCP. From 72 drugs screened in vitro, a total of 31 drugs inhibited NTCP, while 51 drugs (i.e., more than half) inhibited ASBT. Hence, while there was inhibitor overlap, ASBT unexpectedly was more permissive to drug inhibition than was NTCP, and this may be related to NTCP possessing fewer pharmacophore features. Findings reflected that a combination of computational and in vitro approaches enriched the understanding of these poorly characterized transporters and yielded additional chemical probes for possible drug-transporter interaction determinations.
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Reanalysis of generalized sensitivity factors for optical-axis perturbation in nonplanar ring resonators.
Opt Express
PUBLISHED: 02-08-2013
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By utilizing the novel coordinate system for Gaussian beam reflection and the generalized ray matrix for spherical mirror reflection, the generalized sensitivity factors SD1, ST1, SD2 and ST2 influenced by both the radial and axial displacements of a spherical mirror in a nonplanar ring resonator have been obtained. Besides, the singular points of different kinds of non-planar ring resonators under the conditions of incident angle A ranging from 0° to 45° or total coordinate rotation angle ? ranging from 0° to 360° have also been obtained through the analysis of the determinant of the coefficient matrix of the linear equations. The analysis in this paper is important to the cavity design of non-planar ring resonators and it could be helpful to avoid the violent movement of the optical-axis to small misalignment of the mirrors in non-planar ring resonators.
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Electrokinetic supercharging preconcentration prior to CGE analysis of DNA: sensitivity depends on buffer viscosity and electrode configuration.
Electrophoresis
PUBLISHED: 01-22-2013
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Aiming to high sensitivity DNA analysis by CGE, electrokinetic supercharging (EKS) approach was adopted in this article. EKS is known as an online preconcentration technique that combines electrokinetic sample injection (EKI) with transient ITP (tITP). Herein, two factors of buffer viscosity and electrode configuration were studied to further improve EKS performance. An ultralow-viscosity Tris-Boric acid-EDTA (TBE) buffer solution, consisted of 2% low-molecular-weight hydroxypropyl methyl cellulose (HPMC) and 6% mannitol and with pH 8.0 adjusted by boric acid, was applied. The boric acid would make a complex with mannitol and generates borate polyanion, which acts as the leading ion for tITP process. The new electrode configuration, a Pt ring around capillary, was modified on Agilent CE system to lead large amount sample introduction during EKS. The standard DNA sample of ?X174/HaeIII digest was used to evaluate the qualitative and quantitative abilities of the proposed strategy. The 170,000-fold highly diluted sample at concentration of 3.0 ng/mL was enriched by EKS and detected by normal UV detection method. The obtained LOD of the weakest peak of 72 bp fragment was around 7.7 pg/mL, apparently improved more than 10,000-fold in comparison with conventional CGE with UV detection.
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Matrix metalloproteinase-1 gene polymorphisms and periodontitis susceptibility: a meta-analysis based on 11 case-control studies.
Gene
PUBLISHED: 01-20-2013
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Matrix metalloproteinase-1 has been implicated in periodontal disease, but the association between the most-studied Matrix metalloproteinase-1 1G-to-2G polymorphism and the risk of periodontal disease were reported with inconclusive results. Therefore, the aim of this study was to investigate the association between the Matrix metalloproteinase-1 1G-to-2G polymorphism and periodontal disease. Electronic databases search yielded 11 studies with 1447 patients and 1710 control subjects evaluated the association of the polymorphisms of Matrix metalloproteinase-1 1G-to-2G and periodontitis risk were brought into this study. The association was evaluated by odds ratio (OR) and its 95% confidence interval (CI). The overall results showed that the variant genotypes were associated with a significantly increased risk of periodontitis (OR=1.45, 95% CI=1.02-1.26 for 2G/2G vs 1G/1G, and OR=2.27, 95% CI=1.22-4.23 for 2G/2G vs 1G/2G+1G/1G). In the stratified analyses, there was a significantly increased risk for the studies of periodontitis (OR=1.59, 95% CI=1.15-2.21 for 2G/2G vs 1G/1G; OR=3.48, 95% CI=1.39-8.71 for 2G/2G vs 1G/2G+1G/1G), which remained for the studies of Asian populations. And there was a significantly increased risk of severe periodontitis (OR=2.15, 95% CI=1.35-3.43 for 2G/2G vs 1G/1G; OR=2.86, 95% CI=1.31-2.64 for 2G/2G vs 1G/2G+1G/1G; OR=1.6, 95% CI=1.12-2.39 for 1G/2G+2G/2G vs 1G/1G; OR=1.61, 95% CI=1.28-2.03 for 2G allele vs 1G allele). The current study demonstrated that the Matrix metalloproteinase-1-1607 1G-to-2G polymorphism was associated with susceptibility to periodontitis, apparently, severe periodontitis.
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Estrogen receptor-?36 is involved in development of acquired tamoxifen resistance via regulating the growth status switch in breast cancer cells.
Mol Oncol
PUBLISHED: 01-08-2013
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Acquired tamoxifen (TAM) resistance limits the therapeutic benefit of TAM in patients with hormone-dependent breast cancer. The switch from estrogen-dependent to growth factor-dependent growth is a critical step in this process. However, the molecular mechanisms underlying this switch remain poorly understood. In this study, we established a TAM resistant cell sub line (MCF-7/TAM) from estrogen receptor-? (ER-?66) positive breast cancer MCF-7 cells by culturing ER-?66-positive MCF-7 cells in medium plus 1 ?M TAM over 6 months. MCF-7/TAM cells were then found to exhibit accelerated proliferation rate together with enhanced in vitro migratory and invasive ability. And the estrogen receptor-?36 (ER-?36), a novel 36-kDa variant of ER-?66, was dramatically overexpressed in this in vitro model, compared to the parental MCF-7 cells. Meanwhile, the expression of epidermal growth factor receptor (EGFR) in MCF-7/TAM cells was significantly up-regulated both in mRNA level and protein level, and the expression of ER-?66 was greatly down-regulated oppositely. In the subsequent studies, we overexpressed ER-?36 in MCF-7 cells by stable transfection and found that ER-?36 transfected MCF-7 cells (MCF-7/ER-?36) similarly exhibited decreased sensitivity to TAM, accelerated proliferative rate and enhanced in vitro migratory and invasive ability, compared to empty vector transfected MCF-7 cells (MCF-7/V). Real-time qPCR and Western blotting analysis revealed that MCF-7/ER-?36 cells possessed increased EGFR expression but decreased ER-?66 expression both in mRNA level and protein level, compared to MCF-7/V cells. This change in MCF-7/ER-?36 cells could be reversed by neutralizing anti-ER-?36 antibody treatment. Furthermore, knock-down of ER-?36 expression in MCF-7/TAM cells resulted in reduced proliferation rate together with decreased in vitro migratory and invasive ability. Decreased EGFR mRNA and protein expression as well as increased ER-?66 mRNA expression were also observed in MCF-7/TAM cells with down-regulated ER-?36 expression. In addition, blocking EGFR/ERK signaling in MCF-7/ER-?36 cells could restore the expression of ER-?66 partly, suggesting a regulatory function of EGFR/ERK signaling in down-regulation of ER-?66 expression. In conclusion, our results indicated for the first time a regulatory role of ER-?36 in up-regulation of EGFR expression and down-regulation of ER-?66 expression, which could be an underlying mechanism for the growth status switch in breast tumors that contribute to the generation of acquired TAM resistance. And ER-?36 could be considered a potential new therapeutic target in breast tumors which have acquired resistance to TAM.
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Teriflunomide attenuates immunopathological changes in the dark agouti rat model of experimental autoimmune encephalomyelitis.
Front Neurol
PUBLISHED: 01-01-2013
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Teriflunomide is an oral disease-modifying therapy recently approved in several locations for relapsing-remitting multiple sclerosis. To gain insight into the effects of teriflunomide, immunocyte population changes were measured during progression of experimental autoimmune encephalomyelitis in Dark Agouti rats. Treatment with teriflunomide attenuated levels of spinal cord-infiltrating T cells, natural killer cells, macrophages, and neutrophils. Teriflunomide also mitigated the disease-induced changes in immune cell populations in the blood and spleen suggesting an inhibitory effect on pathogenic immune responses.
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Prediction of collision-induced-dissociation spectra of peptides with post-translational or process-induced modifications.
Anal. Chem.
PUBLISHED: 10-28-2011
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Mass spectrometry, combined with collision-induced dissociation (CID), has become the method of choice for analyzing protein post-translational and process-induced modifications. However, confident and automated identification of modifications and modification sites is often challenged by the diversity of modifications and their labile nature under typical CID conditions. An accurate prediction of the CID spectra of modified peptides will improve the reliability of automated determination of modifications and modification sites. In this article, the kinetic model for the prediction of peptide CID spectra is extended to the prediction of the CID spectra of modified peptides. The mathematical model for predicting CID spectra of peptides with enzymatic and chemical modifications such as (1) phosphorylation of serine, threonine, and tyrosine, (2) S-carboxymethylation and carbamidomethylation of cysteine, (3) different stages of oxidation of methionine, tryptophan, and cysteine, (4) glycation of lysine, (5) O-mannosylation of serine, (6) hydroxylation of lysine, and (7) N-monomethylation and N-dimethylation of lysine is described. The mathematical model, once established with CID spectra of peptides with known modifications and modification sites, is able to predict CID spectra with excellent accuracy in ion intensities, facilitating more reliable identification of modification and modification sites.
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The human histone chaperone sNASP interacts with linker and core histones through distinct mechanisms.
Nucleic Acids Res.
PUBLISHED: 09-29-2011
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Somatic nuclear autoantigenic sperm protein (sNASP) is a human homolog of the N1/N2 family of histone chaperones. sNASP contains the domain structure characteristic of this family, which includes a large acidic patch flanked by several tetratricopeptide repeat (TPR) motifs. sNASP possesses a unique binding specificity in that it forms specific complexes with both histone H1 and histones H3/H4. Based on the binding affinities of sNASP variants to histones H1, H3.3, H4 and H3.3/H4 complexes, sNASP uses distinct structural domains to interact with linker and core histones. For example, one of the acidic patches of sNASP was essential for linker histone binding but not for core histone interactions. The fourth TPR of sNASP played a critical role in interactions with histone H3/H4 complexes, but did not influence histone H1 binding. Finally, analysis of cellular proteins demonstrated that sNASP existed in distinct complexes that contained either linker or core histones.
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Rapid LC-MS screening for IgG Fc modifications and allelic variants in blood.
Mol. Immunol.
PUBLISHED: 08-08-2011
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A new method for simultaneously screening allelic variants and certain Fc modifications on endogenous human IgG1 and IgG2 directly from blood samples is described. The IdeS endoproteinase was used to cleave IgG in serum to generate Fc, which, after denaturation, was analyzed directly as monomeric Fc (Fc/2) by LC-MS to identify the haplotype(s) present in each individual. The relative levels of IgG isotype and haplotype ratios were generated along with the profile of the major Fc glycans and several other modifications associated with each IgG1 or IgG2 haplotype. Since only minute quantities (5 ?L) of blood are required and analysis can be highly automated, this approach lends itself to screening large populations. We demonstrate its utility in examining possible correlations between Fc properties and allelic variants. IgG1 core fucosylation, which significantly impacts antibody dependent cellular cytotoxicity (ADCC), showed an asymmetric distribution, with a small number of individuals showing unexpectedly high core afucosylation levels. In these individuals, IgG2 afucosylation levels were normal. Finally, a new IgG1 allotype, previously not characterized, was identified using this analytical methodology.
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Relative changes in krill abundance inferred from Antarctic fur seal.
PLoS ONE
PUBLISHED: 06-30-2011
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Antarctic krill Euphausia superba is a predominant species in the Southern Ocean, it is very sensitive to climate change, and it supports large stocks of fishes, seabirds, seals and whales in Antarctic marine ecosystems. Modern krill stocks have been estimated directly by net hauls and acoustic surveys; the historical krill density especially the long-term one in the Southern Ocean, however, is unknown. Here we inferred the relative krill population changes along the West Antarctic Peninsula (WAP) over the 20th century from the trophic level change of Antarctic fur seal Arctocephalus gazella using stable carbon (?(13)C) and nitrogen (?(15)N) isotopes of archival seal hairs. Since Antarctic fur seals feed preferentially on krill, the variation of ?(15)N in seal hair indicates a change in the proportion of krill in the seals diets and thus the krill availability in local seawater. For the past century, enriching fur seal ?(15)N values indicated decreasing krill availability. This is agreement with direct observation for the past ?30 years and suggests that the recently documented decline in krill populations began in the early parts of the 20th century. This novel method makes it possible to infer past krill population changes from ancient tissues of krill predators.
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Heterogeneity in primary colorectal cancer and its corresponding metastases: a potential reason of EGFR-targeted therapy failure?
Hepatogastroenterology
PUBLISHED: 06-14-2011
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Epidermal growth factor receptor (EGFR)-targeted therapy represents an important approach in metastatic colorectal cancer (CRC) therapy. However, a number of CRC patients show intrinsic or acquired resistance to EGFR-targeted therapy. EGFR antibody therapy is established in CRC patients with wild-type KRAS. However, up to half of these patients do not respond to this therapy. This phenomenon implied some potential mechanisms of resistance to EGFR inhibitors might exist. One of the potential reasons to explain this phenomenon is heterogeneity of CRC. The heterogeneity of CRC has been well described at the morphological, molecular and genomic levels. This review discussed the potential relationship of heterogeneity, including intratumor heterogeneity of CRC and heterogeneity in primary CRC and its corresponding metastases, to EGFR-targeted therapy failure.
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[Effects of Feiyanning on the expression of epithelial-mesenchymal factors in highly metastatic lung cancer cells 95-D].
Zhongguo Fei Ai Za Zhi
PUBLISHED: 06-08-2011
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Our previous in vivo experiment (paper has been published) has confirmed Feiyannings regulation effect on epithelial cell markers Alpha-catenin, beta-catenin, E-Cadherin and mesenchymal cell markers N-cadherin, Fibronectin, vimentin. Based on previous study, the objective of this study is to further investigate the expression of epithelial-mesenchymal cell marker gene and protein intervened by Feiyanning in highly metastatic lung cancer cells 95-D in vitro.
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Poorer prognosis and higher prevalence of BRAF (V600E) mutation in synchronous bilateral papillary thyroid carcinoma.
Ann. Surg. Oncol.
PUBLISHED: 04-18-2011
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The clinical significance of synchronous bilateral papillary thyroid carcinoma (SBiPTC) has not been fully defined, and the prevalence of BRAF (V600E) mutation in SBiPTC remains unknown. The purpose of this study is to compare the clinical outcomes and BRAF (V600E) mutation incidence of SBiPTC patients with those of unilateral papillary thyroid carcinoma (UiPTC) patients.
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Genetic interactions between POB3 and the acetylation of newly synthesized histones.
Curr. Genet.
PUBLISHED: 04-01-2011
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Pob3p is an essential component of the S. cerevisiae FACT complex (yFACT). Several lines of evidence indicate that the yFACT complex plays an important role in chromatin assembly including the observation that the pob3 Q308K allele is synthetically lethal with an allele of histone H4 that prevents the diacetylation of newly synthesized molecules. We have analyzed the genetic interactions between the Q308K allele of POB3 and mutations in all of the sites of acetylation that have been identified on newly synthesized histones. Genetic interactions were observed between POB3 and sites of acetylation on the NH(2)-terminal tails of H3 and H4. For histone H3, lysine residues 14 and 23 were particularly important when POB3 activity is compromised. Surprisingly, synthetic defects observed when the pob3 Q308K allele was combined with mutations of H4 lysines 5 and 12, were not phenocopied by deletion of HAT1, which encodes the enzyme that is thought to generate this pattern of acetylation on H4. Genetic interactions were also observed between POB3 and sites of acetylation found in the core domain of newly synthesized histones H3 and H4. These include synthetic lethality with an allele of H4 lysine 91 that mimics constitutive acetylation. While the mutations that alter H4 lysines 5, 12 and 91 do not affect binding to Pob3p, mutation of histone H3 lysine 56 decreases the association of histones with Pob3p. These results support the model that the yFACT complex plays a central role in chromatin assembly pathways regulated by acetylation of newly synthesized histones.
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High-mannose glycans on the Fc region of therapeutic IgG antibodies increase serum clearance in humans.
Glycobiology
PUBLISHED: 03-18-2011
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Glycan structures attached to the C(H)2 domain of the Fc region of immunoglobulin G (IgG) are essential for specific effector functions but their role in modulating clearance is less clear. Clearance is of obvious importance for therapeutic monoclonal antibodies (Mabs) as it directly impacts efficacy. Here, we study the impact of Fc glycan structure on the clearance of four therapeutic human IgGs (one IgG1 and three IgG2s) in humans. The therapeutic IgGs were affinity purified from serum samples from human pharmacokinetic studies, and changes to the glycan profile over time were determined by peptide mapping employing high-resolution mass spectrometry. Relative levels of high-mannose 5 (M5) glycan decreased as a function of circulation time, whereas other glycans remained constant. These results demonstrate that therapeutic IgGs containing Fc high-mannose glycans are cleared more rapidly in humans than other glycan forms. The quantitative effect of this on pharmacokinetic area under the curve was calculated and shown to be relatively minor for three of the four molecules studied, but, depending on the dosing regimen and the relative level of the high-mannose glycan, this can also have significant impact. High-mannose content of therapeutic Mabs should be considered an important product quality attribute which may affect pharmacokinetic properties of therapeutic antibodies.
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Nuclear Hat1p complex (NuB4) components participate in DNA repair-linked chromatin reassembly.
J. Biol. Chem.
PUBLISHED: 03-17-2011
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Chromatin is disassembled and reassembled during DNA repair. To assay chromatin reassembly accompanying DNA double strand break repair, ChIP analysis can be used to monitor the presence of histone H3 near the lesion. The chromatin assembly factor Asf1p, as well as the acetylation of histone H3 lysine 56, have been shown to promote chromatin reassembly when DNA double strand break repair is complete. Using Gal-HO-mediated double strand break repair, we have tested each of the components of the nuclear Hat1p-containing type B histone acetyltransferase complex (NuB4) and have found that they can affect repair-linked chromatin reassembly but that their contributions are not equivalent. In particular, deletion of the catalytic subunit, Hat1p, caused a significant defect in chromatin reassembly. In addition, loss of the histone chaperone Hif1p, when combined with an allele of H3 that mutates lysines 14 and 23 to arginine, has a pronounced effect on chromatin reassembly that is similar to that observed in an asf1?. The role of Hat1p and Hif1p is at least partially redundant with the role of Asf1p. Consistent with a more prominent role for Hif1p in chromatin reassembly than either Hat1p or Hat2p, Hif1p exists in complex(es) independent of Hat1p and Hat2p and influences the activity of an H3-specific histone acetyltransferase activity. Our data directly demonstrate the role of the nuclear HAT1 complex (NuB4) components in DNA repair-linked chromatin reassembly.
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Effects of different potato cropping system approaches and water management on soilborne diseases and soil microbial communities.
Phytopathology
PUBLISHED: 02-25-2011
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Four different potato cropping systems, designed to address specific management goals of soil conservation, soil improvement, disease suppression, and a status quo standard rotation control, were evaluated for their effects on soilborne diseases of potato and soil microbial community characteristics. The status quo system (SQ) consisted of barley underseeded with red clover followed by potato (2-year). The soil-conserving system (SC) featured an additional year of forage grass and reduced tillage (3-year, barley/timothy-timothy-potato). The soil-improving system (SI) added yearly compost amendments to the SC rotation, and the disease-suppressive system (DS) featured diverse crops with known disease-suppressive capability (3-year, mustard/rapeseed-sudangrass/rye-potato). Each system was also compared with a continuous potato control (PP) and evaluated under both irrigated and nonirrigated conditions. Data collected over three potato seasons following full rotation cycles demonstrated that all rotations reduced stem canker (10 to 50%) relative to PP. The SQ, SC, and DS systems reduced black scurf (18 to 58%) relative to PP; SI reduced scurf under nonirrigated but not irrigated conditions; and scurf was lower in DS than all other systems. The SQ, SC, and DS systems also reduced common scab (15 to 45%), and scab was lower in DS than all other systems. Irrigation increased black scurf and common scab but also resulted in higher yields for most rotations. SI produced the highest yields under nonirrigated conditions, and DS produced high yields and low disease under both irrigation regimes. Each cropping system resulted in distinctive changes in soil microbial community characteristics as represented by microbial populations, substrate utilization, and fatty acid methyl-ester (FAME) profiles. SI tended to increase soil moisture, microbial populations, and activity, as well result in higher proportions of monounsaturated FAMEs and the FAME biomarker for mycorrhizae (16:1 ?6c) relative to most other rotations. DS resulted in moderate microbial populations and activity but higher substrate richness and diversity in substrate utilization profiles. DS also resulted in relatively higher proportions of FAME biomarkers for fungi (18:2 ?6c), actinomycetes, and gram-positive bacteria than most other systems, whereas PP resulted in the lowest microbial populations and activity; substrate richness and diversity; proportions of monounsaturated and polyunsaturated FAME classes; and fungal, mycorrhizae, and actinomycete FAME biomarkers of all cropping systems. Overall, soil water, soil quality, and soilborne diseases were all important factors affecting productivity, and cropping systems addressing these constraints improved production. Cropping system approaches will need to balance these factors to achieve sustainable production and disease management.
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Extranodal follicular dendritic cell sarcoma in mesentery: A case report.
Oncol Lett
PUBLISHED: 02-09-2011
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Extranodal follicular dendritic cell (FDC) sarcomas are not a common phenomenon. Due to the scarcity of the identified cases reported in the literature, FDC is probably under-recognized and commonly misdiagnosed. The diagnosis of FDC sarcomas is based on node-based spindle cell lesions, and the expression of CD21, CD35 and clusterin. The most commonly involved extranodal sites include the oral cavity, tonsil, gastrointestinal tract and liver. With the aid of immunohistochemical analysis and the two most reliable FDC markers, CD21 and CD35, the diagnostic accuracy has improved. When FDC sarcoma is suspected histologically, immunohistochemical stains for FDC differentiation should be performed to avoid potential misdiagnosis. This case report concerns the evaluation of a 43-year-old male Chinese patient with a large extranodal FDC sarcoma (20×18×9 cm) in the mesentery with elevated serum CA125 (76.9 U/ml). The diagnosis and treatment of this disease are also discussed.
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Electrokinetic supercharging with a system-induced terminator and an optimized capillary versus electrode configuration for parts-per-trillion detection of rare-earth elements in CZE.
Electrophoresis
PUBLISHED: 01-10-2011
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A further improvement of electrokinetic supercharging (EKS) methodology has been proposed, with the objective to enhance the sensitivity of the conventional CZE-UV method down to a single-digit part per trillion (ppt) level. The advanced EKS procedure is based on a novel phenomenon displaying the formation of a zone with an increased concentration of the hydrogen ion, capable to perform the function of a terminator, behind the sample zone upon electrokinetic injection. In combination with a visualizing co-ion of BGE, protonated 4-methylbenzylamine, acting as the leading ion, such system-induced terminator a effected the transient ITP state to efficiently concentrate cationic analytes prior to CZE. Furthermore, to amass more analyte ions within the effective electric field at the injection stage, a standard sample vial was replaced with an elongated vial that allowed the sample volume to be increased from 500 to 900 ?L. Alongside, this replacement made the upright distance between the electrode and the capillary tips prolonged to 40.0 mm to achieve high-efficiency electrokinetic injection. The computer simulation was used for profiling analyte concentration, pH, and field strength in order to delineate formation of the terminator during sample injection. The proposed preconcentration strategy afforded an enrichment factor of 80,000 and thereby the LODs of rare-earth metal ions at the ppt level, e.g. 0.04 nM (6.7 ng/L) for erbium(III).
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Automated in-solution protein digestion using a commonly available high-performance liquid chromatography autosampler.
Anal. Biochem.
PUBLISHED: 01-10-2011
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A completely automated peptide mapping liquid chromatography/mass spectrometry (LC/MS) system for characterization of therapeutic proteins in which a common high-performance liquid chromatography (HPLC) autosampler is used for automated sample preparation, including protein denaturation, reduction, alkylation, and enzymatic digestion, is described. The digested protein samples are then automatically subjected to LC/MS analysis using the same HPLC system. The system was used for peptide mapping of monoclonal antibodies (mAbs), known as a challenging group of therapeutic proteins for achieving complete coverage and quantitative representation of all peptides. Detailed sample preparation protocols, using an Agilent HPLC system, are described for Lys-C digestion of mAbs with intact disulfide bonds and tryptic digestion of mAbs after reduction and alkylation. The automated procedure of Lys-C digestion of nonreduced antibody, followed by postdigestion disulfide reduction, produces both the nonreduced and reduced digests that facilitate disulfide linkage analysis. The automated peptide mapping LC/MS system has great utility in preparing and analyzing multiple samples for protein characterization, identification, and quantification of posttranslational modifications during process and formulation development as well as for protein identity and quality control.
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Vaccine-induced control of viral shedding following rhesus cytomegalovirus challenge in rhesus macaques.
J. Virol.
PUBLISHED: 12-29-2010
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The use of animal models of human cytomegalovirus (HCMV) infection is critical to refine HCMV vaccine candidates. Previous reports have demonstrated that immunization of rhesus monkeys against rhesus cytomegalovirus (RhCMV) can reduce both local and systemic replication of RhCMV following experimental RhCMV challenge. These studies used prime/boost combinations of DNA expression plasmids alone or DNA priming and boosting with either inactivated virion particles or modified vaccinia virus Ankara (MVA) expressing the same antigens. Viral outcomes included reduced RhCMV replication at the site of subcutaneous inoculation and RhCMV viremia following intravenous inoculation. Since shedding of cytomegalovirus from mucosal surfaces is critical for horizontal transmission of the virus, DNA priming/MVA boosting was evaluated for the ability to reduce oral shedding of RhCMV following subcutaneous challenge. Of six rhesus monkeys vaccinated exclusively against RhCMV glycoprotein B (gB), phosphoprotein 65 (pp65), and immediate-early 1 (IE1), half showed viral loads in saliva that were lower than those of control monkeys by 1 to 3 orders of magnitude. Further, there was a strong association of memory pp65 T cell responses postchallenge in animals exhibiting the greatest reduction in oral shedding. These results highlight the fact that a DNA/MVA vaccination regimen can achieve a notable reduction in a critical parameter of viral replication postchallenge. The recently completed clinical trial of a gB subunit vaccine in which the rate of HCMV infection was reduced by 50% in the individuals receiving the vaccine is consistent with the results of this study suggesting that additional immunogens are likely essential for maximum protection in an outbred human population.
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[The inhibition activity of chemical constituents in hawthorn fruit and their synergistic action to HMG-CoA reductase].
Zhongguo Zhong Yao Za Zhi
PUBLISHED: 12-15-2010
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To study the hypolipidemic active compounds from Crataegus pinnatifida and mechanism of action of those.
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Another approach toward over 100,000-fold sensitivity increase in capillary electrophoresis: electrokinetic supercharging with optimized sample injection.
Anal. Chem.
PUBLISHED: 12-13-2010
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Electrokinetic supercharging (EKS) is a powerful and practical method for multifold in-line concentration of various analytes prior to capillary electrophoresis (CE) analysis. However, a problem of insufficient sensitivity has always existed when trace analyte quantification by EKS-CE is a target, especially when coupled with conventional detectors. Normally this requires a greatly increased amount of analyte injected without separation degradation. In this contribution, we have shown that it is possible to substantially improve analyte loading and hence CE method detectability by modifying sample introduction configuration. The volume of sample vial was increased (from typical 500 ?L to 17 mL), the common wire electrode was replaced by a ring electrode, and the sample solution was stirred. With these alterations, more analyte ions are accumulated within the effective electric field during electrokinetic injection and then maintained as focused zones due to transient isotachophoresis. The versatility of the customized EKS-CE approach for sample concentration was demonstrated for a mixture of seven rare-earth metal ions with an enrichment factor of 500?000 giving detection limits at or below 1 ng/L. These detection limits are over 100?000 times better than can be achieved by normal hydrodynamic injection, 1000 times better than the sensitivity thresholds of inductively coupled plasma atomic emission spectrometry (ICP-AES), and even close to those of inductively coupled plasma mass spectrometry (ICPMS).
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Prediction of collision-induced dissociation spectra of common N-glycopeptides for glycoform identification.
Anal. Chem.
PUBLISHED: 11-23-2010
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Confident identification of the glycan moieties in glycopeptides by collision-induced dissociation (CID) requires accurate prediction of the CID spectrum of the glycopeptides. In this Article, the kinetic model for the prediction of peptide CID spectra is extended to predict the CID spectra of N-glycopeptides. The model was trained with 1831 ion-trap CID spectra of N-glycopeptides and is able to predict ion-trap CID spectra with excellent accuracy in ion intensities for N-glycopeptides up to 8000 u in mass. A total of 524 common glycoforms including complex N-glycans with 2-4 antennas, plus high-mannose type and hybrid type, can be predicted.
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High-performance soft x-ray spectromicroscopy beamline at SSRF.
Rev Sci Instrum
PUBLISHED: 11-02-2010
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The Shanghai Synchrotron Radiation Facility (SSRF) is the first third-generation synchrotron facility in China and operated at an electron energy of 3.5 GeV. One of the seven beamlines in the first construction phase is devoted to soft x-ray spectromicroscopy and is equipped with an elliptically polarized undulator light source, a plane grating monochromator, and a scanning transmission x-ray microscope end station. Initial results reveal the high performance of this beamline, with an energy resolving power estimated to be over 10,000 at the argon L-edge and a spatial resolution better than 30 nm.
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Ultrahigh resolution mass spectrometry and indicator species analysis to identify marker components of soil- and plant biomass- derived organic matter fractions.
Environ. Sci. Technol.
PUBLISHED: 10-21-2010
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The chemical properties of organic matter affect important soil processes such as speciation, solubilization, and transport of plant nutrients and metals. This work uses ultrahigh resolution electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry to determine the molecular composition of three organic matter fractions of soils and aqueous extracts of crop biomass. Comparison of the van Krevelen plots allowed tracking the changes in organic matter with increasing humification. Aqueous plant biomass extracts contain a diverse mixture of lipids, proteins, and lignins. Soil aqueous extracts were marked by increases in lignin and carbohydrate components and decrease in the protein component as compared to the plant extract. Refractory humic acid fractions were marked by decrease in the lignin component and increases in the lipid and condensed aromatic components. The multivariate indicator species analysis was used to identify marker components of the four organic matter types investigated. The plant extract group had 772 marker components compared to 237 for soil aqueous extract, 92 for mobile humic acid, and 418 for calcium humic acid. This study demonstrates that ultrahigh resolution mass spectrometry and multivariate methods can be used to identify marker components to gain a molecular-scale description and understanding of C dynamics.
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[Metabolism, transformation and distribution of Coptis chinensis total alkaloids in rat].
Zhongguo Zhong Yao Za Zhi
PUBLISHED: 10-12-2010
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To determine the pharmacokinetics, distribution and mutual transformation of the total alkaloids, jatrorrhizine, coptisine, berberine and palmatine from Coptis chinensis in rats.
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Investigation of the pH gradient formation and cathodic drift in microchip isoelectric focusing with imaged UV detection.
Electrophoresis
PUBLISHED: 10-07-2010
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This paper reports the protein analysis by using microchip IEF carried on an automated chip system. We herein focused on two important topics of microchip IEF, the pH gradient and cathodic drift. The computer simulation clarified that the EOF could delay the establishment of pH gradient and move the carrier ampholytes (CAs) to cathode, which probably caused a cathodic drift to happen. After focusing, the peak positions of components in a calibration kit with broad pI were plotted against their pI values to know the actual pH gradient in a microchannel varying time. It was found that the formed pH gradient was stable, not decayed after readily steady state, and migrated to cathode at a rate of 10.0??m/s that determined by the experimental conditions such as chip material, internal surface coating and field strength. The theoretical pH gradient was parallel with the actual pH gradient, which was demonstrated in two types of microchip with different channel lengths. No compression of pH gradient was observed when 2% w/v hydroxypropyl methyl cellulose was added in sample and electrolytes. The effect of CAs concentration on current and cathodic drift was also explored. With the current automatic chip system, the calculated peak capacity was 23-48, and the minimal pI difference was 0.20-0.42 for the used single channel microchip with the effective length of 40.5?mm. The LOD for the analysis of CA-I and CA-II was around 0.32??g/mL by using normal imaged UV detection, the detected amount is ca. 0.07?ng.
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Enhanced neuronal expression of major histocompatibility complex class I leads to aberrations in neurodevelopment and neurorepair.
J. Neuroimmunol.
PUBLISHED: 08-24-2010
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Mice deficient in classical major histocompatibility complex class I (MHCI) have aberrations in neurodevelopment. The consequences of upregulated neuronal MHCI expression have not been examined. We found that transgenic C57Bl/6 mice that are engineered to express higher levels of self-D(b) on their CNS neurons have alterations in their hippocampal morphology and retinogeniculate projections, as well as impaired neurorepair responses. Thus, enhanced neuronal classical MHCI expression can lead to aberrations in neural circuitry and neurorepair. These findings complement a growing body of knowledge concerning the neurobiological activities of MHCI and may have potential clinical relevance.
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Major histocompatibility complex class I-mediated inhibition of neurite outgrowth from peripheral nerves.
Immunol. Lett.
PUBLISHED: 06-25-2010
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Studies of mice deficient in classical major histocompatability complex class I (MHCI) revealed that MHCI plays an important role in neurodevelopment in the central nervous system. We previously studied the effects of recombinant MHCI molecules on wildtype retina explants and observed that MHCI can inhibit retina neurite outgrowth, with self-MHCI molecules having greater inhibitory effect than non-self MHCI molecules. Here, we examined classical MHCIs effects on axon outgrowth from neurons of the peripheral nervous system (PNS). We used the embryonic dorsal root ganglia (DRG) explant model since their neurons express MHCI and because DRG explants have been widely used to assess the effects of molecules on axonal outgrowth from PNS neurons. We observed that picomolar levels of a recombinant self-MHCI molecule, but not non-self MHCI molecules, inhibited axon outgrowth from DRG explants. This differential sensitivity to self- vs. non-self MHCI suggests that early in development, self-MHCI may "educate" PNS neurons to express appropriate MHCI receptors, as occurs during natural killer cell development. Furthermore, we observed that a MHCI tetramer stained embryonic DRG neurons, indicating the expression of classical MHCI receptors. These results suggest that MHCI and MHCI receptors play roles during early stages of PNS development and may provide new targets of therapeutic strategies to promote neuronal outgrowth after PNS injury.
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Transgenic mice with enhanced neuronal major histocompatibility complex class I expression recover locomotor function better after spinal cord injury.
J. Neurosci. Res.
PUBLISHED: 06-23-2010
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Mice that are deficient in classical major histocompatibility complex class I (MHCI) have abnormalities in synaptic plasticity and neurodevelopment and have more extensive loss of synapses and reduced axon regeneration after sciatic nerve transection, suggesting that MHCI participates in maintaining synapses and axon regeneration. Little is known about the biological consequences of up-regulating MHCIs expression on neurons. To understand MHCIs neurobiological activity better, and in particular its role in neurorepair after injury, we have studied neurorepair in a transgenic mouse model in which classical MHCI expression is up-regulated only on neurons. Using a well-established spinal cord injury (SCI) model, we observed that transgenic mice with elevated neuronal MHCI expression had significantly better recovery of locomotor abilities after SCI than wild-type mice. Although previous studies have implicated inflammation as both deleterious and beneficial for recovery after SCI, our results point directly to enhanced neuronal MHCI expression as a beneficial factor for promoting recovery of locomotor function after SCI.
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The synthesis and biological evaluation of quinolyl-piperazinyl piperidines as potent serotonin 5-HT1A antagonists.
J. Med. Chem.
PUBLISHED: 05-07-2010
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As part of an effort to identify 5-HT(1A) antagonists that did not possess typical arylalkylamine or keto/amido-alkyl aryl piperazine scaffolds, prototype compound 10a was identified from earlier work in a combined 5-HT(1A) antagonist/SSRI program. This quinolyl-piperazinyl piperidine analogue displayed potent, selective 5-HT(1A) antagonism but suffered from poor oxidative metabolic stability, resulting in low exposure following oral administration. SAR studies, driven primarily by in vitro liver microsomal stability assessment, identified compound 10b, which displayed improved oral bioavailability and lower intrinsic clearance. Further changes to the scaffold (e.g., 10r) resulted in a loss in potency. Compound 10b displayed cognitive enhancing effects in a number of animal models of learning and memory, enhanced the antidepressant-like effects of the SSRI fluoxetine, and reversed the sexual dysfunction induced by chronic fluoxetine treatment.
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JoVE Visualize is a tool created to match the last 5 years of PubMed publications to methods in JoVE's video library.

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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.