124 results on '"Marshall JG"'
Search Results
2. OR 59 Dentinal crack incidence and post removal time by ultrasonic or mechanical force
- Author
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Altshul, JH, primary, Marshall, JG, additional, Morgan, LA, additional, and Baumgartner, JC, additional
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- 1997
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3. The health sciences librarian in medical education: a vital pathways project task force.
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Schwartz DG, Blobaum PM, Shipman JP, Markwell LG, and Marshall JG
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Objectives: The Medical Education Task Force of the Task Force on Vital Pathways for Hospital Librarians reviewed current and future roles of health sciences librarians in medical education at the graduate and undergraduate levels and worked with national organizations to integrate library services, education, and staff into the requirements for training medical students and residents. Methods: Standards for medical education accreditation programs were studied, and a literature search was conducted on the topic of the role of the health sciences librarian in medical education. Results: Expectations for library and information services in current standards were documented, and a draft standard prepared. A comprehensive bibliography on the role of the health sciences librarian in medical education was completed, and an analysis of the services provided by health sciences librarians was created. Conclusion: An essential role and responsibility of the health sciences librarian will be to provide the health care professional with the skills needed to access, manage, and use library and information resources effectively. Validation and recognition of the health sciences librarian's contributions to medical education by accrediting agencies will be critical. The opportunity lies in health sciences librarians embracing the diverse roles that can be served in this vital activity, regardless of accrediting agency mandates. [ABSTRACT FROM AUTHOR]
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- 2009
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4. Cancer screening in women with chronic illness: the unanswered questions.
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Marshall JG
- Abstract
The literature offers conflicting results regarding whether the cancer screening needs of women with chronic illness are being met. Cancer screening in this population of women is in need of further investigation to address its cost effectiveness, the health care system's priority and management of screening the risks of cancer-related illness in women with co-morbidities, and the perceptions of the affected women. While other care providers are often focused on disease management, nurses who pride themselves with providing holistic care can take an active role in ensuring all women receive preventive health screening. [ABSTRACT FROM AUTHOR]
- Published
- 2004
5. Building a model business case: current awareness service in a special library.
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Harris G and Marshall JG
- Published
- 1996
6. End-user training: does it make a difference?
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Marshall JG
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- 1989
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7. Heparin-Lock Maintenance Solutions
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Marshall Jg
- Subjects
Heparin lock ,business.industry ,Anesthesia ,medicine ,General Medicine ,Heparin ,business ,medicine.drug - Published
- 1976
8. Trypsin Digestion Conditions of Human Plasma for Observation of Peptides and Proteins from Tandem Mass Spectrometry.
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Chen ZZ, Dufresne J, Bowden P, Miao M, and Marshall JG
- Abstract
Previous meta-analysis indicated that plasma or serum proteome groups using various experimental conditions detected different peptides from the same plasma proteins, which is strong evidence for the veracity of blood fluid LC-ESI-MS/MS but also evidences that the trypsin digestion step is a key source of variation in plasma proteomics. Agreement between different digestion conditions and MS/MS algorithms may serve as an independent confirmation of the validity of the LC-ESI-MS/MS analysis of plasma peptides. Plasma contains a high percentage of albumin held together by multiple disulfide bonds; hence, reduction and/or alkylation may greatly enhance the digestion efficiency of albumin. Plasma proteins were precipitated in 90% acetonitrile, collected over quaternary amine resin, and eluted in NaCl prior to digestion treatments. To determine the effect of trypsin digestion methods, the plasma proteins were digested in 600 mM urea and 5% acetonitrile with trypsin alone, or reduced with 2 mM DTT followed by trypsin, or DTT followed by 15 mM iodoacetamide and then trypsin. The resulting peptides were analyzed by LC-ESI-MS/MS with a linear quadrupole ion trap (LIT). The MS/MS spectra were directly fit to peptides by the X!TANDEM and SEQUEST algorithms. Blank noise injections served as the analytical control, and 30 million random MS/MS served as the statistical control. Digesting human plasma with DTT reduction, or reduction and alkylation, resulted in a dramatic increase in the number and observation frequency of albumin peptides. In contrast, digestion with trypsin alone suppressed the observation of albumin, and instead, many low abundance plasma and cellular proteins showed higher observation frequency. Digestion with trypsin alone increased the observation frequency of APOC1, ACAN, ATRN, CPB2, GP2, GPX3, HBA1, PAPD5, PKD1, and many cellular proteins. After correction against noise and random controls, SEQUEST showed good agreement with the true positive plasma proteins identified by X!TANDEM and resulted in an R -squared of 0.5238 with an F -statistic of 10,930 on 9,935 protein gene symbols with a p -value < 2.2e-16. Digestion of plasma with trypsin alone avoids the complete digestion of albumin and permits the enhanced detection of some other cellular proteins from plasma. Different digestion approaches were complimentary and together resulted in a more comprehensive plasma proteome. The protein FDR q -values, the modest effect of background and Monte Carlo correction, and the significant STRING analysis were all consistent with the high fidelity of the rigorous X!TANDEM algorithm. In contrast, SEQUEST required significant correction against noise and statistical controls and selection of high cross correlation (XCorr) scores to show good agreement with X!TANDEM. There was qualitative and quantitative agreement between plasma proteins digested without alkylation from the orbital ion trap (OIT) versus the LIT instrument that showed highly significant regression against the X!TANDEM OIT monoisotopic results, those from heavy isotopes and other masses from X!TANDEM, and with those from MaxQuant. There was significant qualitative and quantitative agreement between the complementary digestion conditions consistent with the good fidelity of plasma analysis by LC-ESI-MS/MS with a sensitive linear ion trap., Competing Interests: The authors declare no competing financial interest., (© 2024 The Authors. Published by American Chemical Society.)
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- 2024
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9. Extraction of naturally occurring peptides versus the tryptic digestion of proteins from fetal versus adult bovine serum for LC-ESI-MS/MS.
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Chen ZZ, Dufresne J, Bowden P, Miao M, and Marshall JG
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- Peptides chemistry, Blood Proteins analysis, Digestion, Tandem Mass Spectrometry methods, Spectrometry, Mass, Electrospray Ionization methods
- Abstract
The naturally occurring peptides and digested proteins of fetal versus adult bovine serum were compared by LC-ESI-MS/MS after correction against noise from blank injections and random MS/MS spectra as statistical controls. Serum peptides were extracted by differential precipitation with mixtures of acetonitrile and water. Serum proteins were separated by partition chromatography over quaternary amine resin followed by tryptic digestion. The rigorous X!TANDEM goodness of fit algorithm that has a low error rate as demonstrated by low FDR q-values (q ≤ 0.01) showed qualitative and quantitative agreement with the SEQUEST cross correlation algorithm on 12,052 protein gene symbols. Tryptic digestion provided a quantitative identification of the serum proteins where observation frequency reflected known high abundance. In contrast, the naturally occurring peptides reflected the cleavage of common serum proteins such as C4A, C3, FGB, HPX, A2M but also proteins in lower concentration such as F13A1, IK, collagens and protocadherins. Proteins associated with cellular growth and development such as actins (ACT), ribosomal proteins like Ribosomal protein S6 (RPS6), synthetic enzymes and extracellular matrix factors were enriched in fetal calf serum. In contrast to the large literature from cord blood, IgG light chains were absent from fetal serum as observed by LC-ESI-MS/MS and confirmed by ELISA., Competing Interests: Declaration of competing interest The authors declare that they have no competing interests., (Copyright © 2024 Elsevier Inc. All rights reserved.)
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- 2024
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10. Mitochondria and cytochrome components released into the plasma of severe COVID-19 and ICU acute respiratory distress syndrome patients.
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Chen ZZ, Johnson L, Trahtemberg U, Baker A, Huq S, Dufresne J, Bowden P, Miao M, Ho JA, Hsu CC, Dos Santos CC, and Marshall JG
- Abstract
Introduction: Proteomic analysis of human plasma by LC-ESI-MS/MS has discovered a limited number of new cellular protein biomarkers that may be confirmed by independent biochemical methods. Analysis of COVID-19 plasma has indicated the re-purposing of known biomarkers that might be used as prognostic markers of COVID-19 infection. However, multiple molecular approaches have previously indicated that the SARS-COV2 infection cycle is linked to the biology of mitochondria and that the response to infections may involve the action of heme containing oxidative enzymes., Methods: Human plasma from COVID-19 and ICU-ARDS was analyzed by classical analytical biochemistry techniques and classical frequency-based statistical approaches to look for prognostic markers of severe COVID-19 lung damage. Plasma proteins from COVID-19 and ICU-ARDS were identified and enumerated versus the controls of normal human plasma (NHP) by LC-ESI-MS/MS. The observation frequency of proteins detected in COVID-19 and ICU-ARDS patients were compared to normal human plasma, alongside random and noise MS/MS spectra controls, using the Chi Square (χ
2 ) distribution., Results: PCR showed the presence of MT-ND1 DNA in the plasma of COVID-19, ICU-ARDS, as well as normal human plasma. Mitochondrial proteins such as MRPL, L2HGDH, ATP, CYB, CYTB, CYP, NDUF and others, were increased in COVID-19 and ICU-ARDS plasma. The apparent activity of the cytochrome components were tested alongside NHP by dot blotting on PVDF against a purified cytochrome c standard preparation for H2 O2 dependent reaction with luminol as measured by enhanced chemiluminescence (ECL) that showed increased activity in COVID-19 and ICU-ARDS patients., Discussion: The results from PCR, LC-ESI-MS/MS of tryptic peptides, and cytochrome ECL assays confirmed that mitochondrial components were present in the plasma, in agreement with the established central role of the mitochondria in SARS-COV-2 biology. The cytochrome activity assay showed that there was the equivalent of at least nanogram amounts of cytochrome(s) in the plasma sample that should be clearly detectable by LC-ESI-MS/MS. The release of the luminol oxidase activity from cells into plasma forms the basis of a simple and rapid test for the severity of cell damage and lung injury in COVID-19 infection and ICU-ARDS., (© 2023. The Author(s).)- Published
- 2023
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11. LEDGF is a new growth factor in fetal serum.
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Chen ZZ, Bowden P, Dufresne J, Miao M, and Marshall JG
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- Animals, Epidermal Growth Factor pharmacology, Intercellular Signaling Peptides and Proteins, Mammals metabolism, Transcription Factors genetics, Insulins, Tandem Mass Spectrometry
- Abstract
Fetal serum supports the immortal growth of mammalian cell lines in culture while adult serum leads to the terminal differentiation and death of cells in culture. Many of the proteins in fetal serum that support the indefinite division and growth of cancerous cell lines remain obscure. The peptides and proteins of fetal versus adult serum were analyzed by liquid chromatography, nano electrospray ionization and tandem mass spectrometry (LC-ESI-MS/MS). Three batches of fetal serum contained the Alpha Fetoprotein marker while adult serum batches did not. Insulin (INS), and insulin-like growth factor (ILGF), fibroblast growth factor (FGF), epidermal growth factor (EGF) and platelet derived growth factor (PDGF) were increased in fetal serum. New fetal growth factors including MEGF, HDGFRP and PSIP1 and soluble growth receptors such as TNFR, EGFR, NTRK2 and THRA were discovered. Addition of insulin or the homeotic transcription factor PSIP1, also referred to as Lens Epithelium Derived Growth Factor (LEDGF), partially restored the rounded phenotype of rapidly dividing cells but was not as effective as fetal serum. Thus, a new growth factor in fetal serum, LEDGF/PSIP1, was directly observed by tandem mass spectrometry and confirmed by add back experiments to cell culture media alongside insulin., Competing Interests: Declaration of competing interest The authors declare that they have no competing interests., (Copyright © 2022. Published by Elsevier Inc.)
- Published
- 2022
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12. The plasma peptides of Alzheimer's disease.
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Florentinus-Mefailoski A, Bowden P, Scheltens P, Killestein J, Teunissen C, and Marshall JG
- Abstract
Background: A practical strategy to discover proteins specific to Alzheimer's dementia (AD) may be to compare the plasma peptides and proteins from patients with dementia to normal controls and patients with neurological conditions like multiple sclerosis or other diseases. The aim was a proof of principle for a method to discover proteins and/or peptides of plasma that show greater observation frequency and/or precursor intensity in AD. The endogenous tryptic peptides of Alzheimer's were compared to normals, multiple sclerosis, ovarian cancer, breast cancer, female normal, sepsis, ICU Control, heart attack, along with their institution-matched controls, and normal samples collected directly onto ice., Methods: Endogenous tryptic peptides were extracted from blinded, individual AD and control EDTA plasma samples in a step gradient of acetonitrile for random and independent sampling by LC-ESI-MS/MS with a set of robust and sensitive linear quadrupole ion traps. The MS/MS spectra were fit to fully tryptic peptides within proteins identified using the X!TANDEM algorithm. Observation frequency of the identified proteins was counted using SEQUEST algorithm. The proteins with apparently increased observation frequency in AD versus AD Control were revealed graphically and subsequently tested by Chi Square analysis. The proteins specific to AD plasma by Chi Square with FDR correction were analyzed by the STRING algorithm. The average protein or peptide log
10 precursor intensity was compared across disease and control treatments by ANOVA in the R statistical system., Results: Peptides and/or phosphopeptides of common plasma proteins such as complement C2, C7, and C1QBP among others showed increased observation frequency by Chi Square and/or precursor intensity in AD. Cellular gene symbols with large Chi Square values (χ2 ≥ 25, p ≤ 0.001) from tryptic peptides included KIF12, DISC1, OR8B12, ZC3H12A, TNF, TBC1D8B, GALNT3, EME2, CD1B, BAG1, CPSF2, MMP15, DNAJC2, PHACTR4, OR8B3, GCK, EXOSC7, HMGA1 and NT5C3A among others. Similarly, increased frequency of tryptic phosphopeptides were observed from MOK, SMIM19, NXNL1, SLC24A2, Nbla10317, AHRR, C10orf90, MAEA, SRSF8, TBATA, TNIK, UBE2G1, PDE4C, PCGF2, KIR3DP1, TJP2, CPNE8, and NGF amongst others. STRING analysis showed an increase in cytoplasmic proteins and proteins associated with alternate splicing, exocytosis of luminal proteins, and proteins involved in the regulation of the cell cycle, mitochondrial functions or metabolism and apoptosis. Increases in mean precursor intensity of peptides from common plasma proteins such as DISC1, EXOSC5, UBE2G1, SMIM19, NXNL1, PANO, EIF4G1, KIR3DP1, MED25, MGRN1, OR8B3, MGC24039, POLR1A, SYTL4, RNF111, IREB2, ANKMY2, SGKL, SLC25A5, CHMP3 among others were associated with AD. Tryptic peptides from the highly conserved C-terminus of DISC1 within the sequence MPGGGPQGAPAAAGGGGVSHRAGSRDCLPPAACFR and ARQCGLDSR showed a higher frequency and highest intensity in AD compared to all other disease and controls., Conclusion: Proteins apparently expressed in the brain that were directly related to Alzheimer's including Nerve Growth Factor (NFG), Sphingomyelin Phosphodiesterase, Disrupted in Schizophrenia 1 (DISC1), the cell death regulator retinitis pigmentosa (NXNl1) that governs the loss of nerve cells in the retina and the cell death regulator ZC3H12A showed much higher observation frequency in AD plasma vs the matched control. There was a striking agreement between the proteins known to be mutated or dis-regulated in the brains of AD patients with the proteins observed in the plasma of AD patients from endogenous peptides including NBN, BAG1, NOX1, PDCD5, SGK3, UBE2G1, SMPD3 neuronal proteins associated with synapse function such as KSYTL4, VTI1B and brain specific proteins such as TBATA.- Published
- 2021
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13. Linear and Gaussian Analysis of a Single Enzyme Molecule by LC-MS.
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Cheng N, Chen ZZ, Florentinus-Mefailoski A, Miao M, and Marshall JG
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- Adenosine Monophosphate metabolism, Alkaline Phosphatase chemistry, Enzymes analysis, Limit of Detection, Normal Distribution, Single Molecule Imaging statistics & numerical data, Streptavidin analysis, Streptavidin chemistry, Alkaline Phosphatase analysis, Chromatography, Liquid methods, Single Molecule Imaging methods, Spectrometry, Mass, Electrospray Ionization methods
- Abstract
The alkaline phosphatase-streptavidin enzyme amplification conjugate (APSA) was diluted and quantified to the equivalent of one enzyme molecule injected on column by monitoring the production of excess adenosine from adenosine monophosphate (AMP) using sensitive and selective enzyme-linked mass spectrometric assay. The APSA enzyme conjugate has a mass of about 195 kDa and catalyzed the production of millions of enzyme products over the course of incubation that may be sensitively quantified by liquid chromatography, electrospray ionization, and mass spectrometry. APSA enzyme conjugate from fg/mL to ag/mL alongside 0 g/mL (control) was incubated with the substrate 1 mM AMP for 2 h in free solution before collecting a 1 μL of sample of the enzyme product adenosine for injection and analysis by LC-MS. The enzyme product adenosine showed a Gaussian distribution after log
10 transformation. The safe limit of detection and quantification was approximately 250 zg of APSA enzyme conjugate injected on column. A linear signal with acceptable error was observed at the mass of the enzyme product adenosine from 10 to 10000 zg of APSA enzyme conjugate injected, compared to controls without enzyme. It was possible to make a linear and Gaussian measurement to the single molecule range of the universal APSA enzyme amplification conjugate per micro liter injected with approximately 10% error. This study describes the first linear and Gaussian quantification of enzyme product from the equivalent of one enzyme conjugate molecule injected onto LC-MS for analysis.- Published
- 2021
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14. The plasma peptides of sepsis.
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Thavarajah T, Dos Santos CC, Slutsky AS, Marshall JC, Bowden P, Romaschin A, and Marshall JG
- Abstract
Background: A practical strategy to discover sepsis specific proteins may be to compare the plasma peptides and proteins from patients in the intensive care unit with and without sepsis. The aim was to discover proteins and/or peptides that show greater observation frequency and/or precursor intensity in sepsis. The endogenous tryptic peptides of ICU-Sepsis were compared to ICU Control, ovarian cancer, breast cancer, female normal, sepsis, heart attack, Alzheimer's and multiple sclerosis along with their institution-matched controls, female normals and normal samples collected directly onto ice., Methods: Endogenous tryptic peptides were extracted from individual sepsis and control EDTA plasma samples in a step gradient of acetonitrile for random and independent sampling by LC-ESI-MS/MS with a set of robust and sensitive linear quadrupole ion traps. The MS/MS spectra were fit to fully tryptic peptides within proteins using the X!TANDEM algorithm. The protein observation frequency was counted using the SEQUEST algorithm after selecting the single best charge state and peptide sequence for each MS/MS spectra. The protein observation frequency of ICU-sepsis versus ICU Control was subsequently tested by Chi square analysis. The average protein or peptide log
10 precursor intensity was compared across disease and control treatments by ANOVA in the R statistical system., Results: Peptides and/or phosphopeptides of common plasma proteins such as ITIH3, SAA2, SAA1, and FN1 showed increased observation frequency by Chi square (χ2 > 9, p < 0.003) and/or precursor intensity in sepsis. Cellular gene symbols with large Chi square values from tryptic peptides included POTEB, CTNNA1, U2SURP, KIF24, NLGN2, KSR1, GTF2H1, KIT, RPS6KL1, VAV2, HSPA7, SMC2, TCEB3B, ZNF300, SUPV3L1, ADAMTS20, LAMB4, MCCC1, SUPT6H, SCN9A, SBNO1, EPHA1, ABLIM2, cB5E3.2, EPHA10, GRIN2B, HIVEP2, CCL16, TKT, LRP2 and TMF1 amongst others showed increased observation frequency. Similarly, increased frequency of tryptic phosphopeptides were observed from POM121C, SCN8A, TMED8, NSUN7, SLX4, MADD, DNLZ, PDE3B, UTY, DEPDC7, MTX1, MYO1E, RXRB, SYDE1, FN1, PUS7L, FYCO1, USP26, ACAP2, AHI1, KSR2, LMAN1, ZNF280D and SLC8A2 amongst others. Increases in mean precursor intensity in peptides from common plasma proteins such as ITIH3, SAA2, SAA1, and FN1 as well as cellular proteins such as COL24A1, POTEB, KANK1, SDCBP2, DNAH11, ADAMTS7, MLLT1, TTC21A, TSHR, SLX4, MTCH1, and PUS7L among others were associated with sepsis. The processing of SAA1 included the cleavage of the terminal peptide D/PNHFRPAGLPEKY from the most hydrophilic point of SAA1 on the COOH side of the cystatin C binding that was most apparent in ICU-Sepsis patients compared to all other diseases and controls. Additional cleavage of SAA1 on the NH2 terminus side of the cystatin binding site were observed in ICU-Sepsis. Thus there was disease associated variation in the processing of SAA1 in ICU-Sepsis versus ICU controls or other diseases and controls., Conclusion: Specific proteins and peptides that vary between diseases might be discovered by the random and independent sampling of multiple disease and control plasma from different hospital and clinics by LC-ESI-MS/MS for storage in a relational SQL Server database and analysis with the R statistical system that will be a powerful tool for clinical research. The processing of SAA1 may play an unappreciated role in the inflammatory response to Sepsis., Competing Interests: Competing interestsThe authors declare that they have no competing interests., (© The Author(s) 2020.)- Published
- 2020
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15. Re-evaluation of the 18 non-human protein standards used to create the empirical statistical model for decoy library searching.
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Thavarajah T, Tucholska M, Zhu PH, Bowden P, and Marshall JG
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- Animals, Humans, Reference Standards, Tandem Mass Spectrometry, Databases, Protein, Proteins standards
- Abstract
The Empirical Statistical Model (ESM) for decoy library searching fused the expected amino acid sequence of 18 non-human protein standards to a human decoy library. The ESM assumed a priori the standards were pure such that only the 18 nominal proteins were true positive, all other proteins were false positive, there was no overlap in the peptides of non-human proteins versus human proteins, and that the score distribution of individual peptides would resolve true positive from false positive results or noise. The results of random and independent sampling by LC-ESI-MS/MS indicated that the fundamental assumptions of the ESM were not in good agreement with the actual purity of the commercial test standards and so the method showed a 99.7% false negative rate. The ESM for decoy library searching apparently showed poor agreement with SDS-PAGE using silver staining, goodness of fit of MS/MS spectra by X!TANDEM, FDR correction by Benjamini and Hochberg, or comparison to the observation frequency of null random MS/MS spectra, that all confirmed the standards contain hundreds of proteins with a low FDR of primary structural identification. The protein observation frequency increased with abundance and the log
10 precursor intensity distributions were Gaussian and nearly ideal for relative quantification., (Copyright © 2020. Published by Elsevier Inc.)- Published
- 2020
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16. Accuracy of Presurgical Limited Field of View Cone-beam Computed Tomography in Predicting Intraoperative Buccal Cortical Bone.
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Mayo CV Jr, Replogle KJ, Marshall JG, Best AM, Sehgal HS, Sousa Melo SL, and Sedgley CM
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- Cortical Bone diagnostic imaging, Humans, Retrospective Studies, Cone-Beam Computed Tomography, Microsurgery
- Abstract
Introduction: Limited field of view cone-beam computed tomography (LFOV CBCT) is the primary imaging modality recommended for treatment planning before endodontic microsurgery (EMS). Persistent apical periodontitis, often treated with EMS, results in changes in the buccal cortical plate that may detrimentally impact prognosis. The accuracy of a preoperative LFOV CBCT to predict intraoperative findings is unclear., Methods: Electronic health records (EHRs) of EMS performed at 2 endodontic offices between 2016 and 2018 were reviewed retrospectively. EHR data extracted were documented for surgical findings of intact buccal cortical plate, fenestration, dehiscence, and height of remaining buccal collar of bone. Two calibrated, independent reviewers evaluated presurgical LFOV CBCTs in the multiplanar paraxial and parasagittal planes at 2 different reconstructed viewing plane thicknesses. Reviewer findings were compared with EHR documentation. Data were analyzed by using χ
2 , logistic regression, and multivariable analysis. Significance was set at P < .05., Results: Within the 125 EMS cases included in the study, the EHR prevalence of intact buccal cortical plate was 49%, dehiscence 7%, and fenestration 44%. The imaging predictive value, whether it was negative (NPV) or positive (PPV), was higher when predicting presence of buccal bone (PPV of intact buccal cortical plate = 86.5%; NPV of dehiscence = 96%; NPV of fenestration = 89%). Sensitivity and specificity ranged from 80%-90%. Accuracy in prediction was high for all variables, exceeding 80%. Accuracy was not significantly influenced by reconstructed viewing slice thickness, viewing plane, or reviewer., Conclusion: Preoperative LFOV CBCT was highly discriminatory and accurately predicted intraoperative buccal cortical bone status, especially intact buccal cortical plate and fenestration., (Copyright © 2019 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.)- Published
- 2020
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17. The plasma peptides of breast versus ovarian cancer.
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Dufresne J, Bowden P, Thavarajah T, Florentinus-Mefailoski A, Chen ZZ, Tucholska M, Norzin T, Ho MT, Phan M, Mohamed N, Ravandi A, Stanton E, Slutsky AS, Dos Santos CC, Romaschin A, Marshall JC, Addison C, Malone S, Heyland D, Scheltens P, Killestein J, Teunissen C, Diamandis EP, Siu KWM, and Marshall JG
- Abstract
Background: There is a need to demonstrate a proof of principle that proteomics has the capacity to analyze plasma from breast cancer versus other diseases and controls in a multisite clinical trial design. The peptides or proteins that show a high observation frequency, and/or precursor intensity, specific to breast cancer plasma might be discovered by comparison to other diseases and matched controls. The endogenous tryptic peptides of breast cancer plasma were compared to ovarian cancer, female normal, sepsis, heart attack, Alzheimer's and multiple sclerosis along with the institution-matched normal and control samples collected directly onto ice., Methods: Endogenous tryptic peptides were extracted from individual breast cancer and control EDTA plasma samples in a step gradient of acetonitrile, and collected over preparative C18 for LC-ESI-MS/MS with a set of LTQ XL linear quadrupole ion traps working together in parallel to randomly and independently sample clinical populations. The MS/MS spectra were fit to fully tryptic peptides or phosphopeptides within proteins using the X!TANDEM algorithm. The protein observation frequency was counted using the SEQUEST algorithm after selecting the single best charge state and peptide sequence for each MS/MS spectra. The observation frequency was subsequently tested by Chi Square analysis. The log
10 precursor intensity was compared by ANOVA in the R statistical system., Results: Peptides and/or phosphopeptides of common plasma proteins such as APOE, C4A, C4B, C3, APOA1, APOC2, APOC4, ITIH3 and ITIH4 showed increased observation frequency and/or precursor intensity in breast cancer. Many cellular proteins also showed large changes in frequency by Chi Square (χ2 > 100, p < 0.0001) in the breast cancer samples such as CPEB1, LTBP4, HIF-1A, IGHE, RAB44, NEFM, C19orf82, SLC35B1, 1D12A, C8orf34, HIF1A, OCLN, EYA1, HLA-DRB1, LARS, PTPDC1, WWC1, ZNF562, PTMA, MGAT1, NDUFA1, NOGOC, OR1E1, OR1E2, CFI, HSA12, GCSH, ELTD1, TBX15, NR2C2, FLJ00045, PDLIM1, GALNT9, ASH2L, PPFIBP1, LRRC4B, SLCO3A1, BHMT2, CS, FAM188B2, LGALS7, SAT2, SFRS8, SLC22A12, WNT9B, SLC2A4, ZNF101, WT1, CCDC47, ERLIN1, SPFH1, EID2, THOC1, DDX47, MREG, PTPRE, EMILIN1, DKFZp779G1236 and MAP3K8 among others. The protein gene symbols with large Chi Square values were significantly enriched in proteins that showed a complex set of previously established functional and structural relationships by STRING analysis. An increase in mean precursor intensity of peptides was observed for QSER1 as well as SLC35B1, IQCJ-SCHIP1, MREG, BHMT2, LGALS7, THOC1, ANXA4, DHDDS, SAT2, PTMA and FYCO1 among others. In contrast, the QSER1 peptide QPKVKAEPPPK was apparently specific to ovarian cancer., Conclusion: There was striking agreement between the breast cancer plasma peptides and proteins discovered by LC-ESI-MS/MS with previous biomarkers from tumors, cells lines or body fluids by genetic or biochemical methods. The results indicate that variation in plasma peptides from breast cancer versus ovarian cancer may be directly discovered by LC-ESI-MS/MS that will be a powerful tool for clinical research. It may be possible to use a battery of sensitive and robust linear quadrupole ion traps for random and independent sampling of plasma from a multisite clinical trial., Competing Interests: Competing interestsThe authors declare that they have no competing interests., (© The Author(s) 2019.)- Published
- 2019
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18. The plasma peptides of ovarian cancer.
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Dufresne J, Bowden P, Thavarajah T, Florentinus-Mefailoski A, Chen ZZ, Tucholska M, Norzin T, Ho MT, Phan M, Mohamed N, Ravandi A, Stanton E, Slutsky AS, Dos Santos CC, Romaschin A, Marshall JC, Addison C, Malone S, Heyland D, Scheltens P, Killestein J, Teunissen CE, Diamandis EP, Michael Siu KW, and Marshall JG
- Abstract
Background: It may be possible to discover new diagnostic or therapeutic peptides or proteins from blood plasma by using liquid chromatography and tandem mass spectrometry to identify, quantify and compare the peptides cleaved ex vivo from different clinical populations. The endogenous tryptic peptides of ovarian cancer plasma were compared to breast cancer and female cancer normal controls, other diseases with their matched or normal controls, plus ice cold plasma to control for pre-analytical variation., Methods: The endogenous tryptic peptides or tryptic phospho peptides (i.e. without exogenous digestion) were analyzed from 200 μl of EDTA plasma. The plasma peptides were extracted by a step gradient of organic/water with differential centrifugation, dried, and collected over C18 for analytical HPLC nano electrospray ionization and tandem mass spectrometry (LC-ESI-MS/MS) with a linear quadrupole ion trap. The endogenous peptides of ovarian cancer were compared to multiple disease and normal samples from different institutions alongside ice cold controls. Peptides were randomly and independently sampled by LC-ESI-MS/MS. Precursor ions from peptides > E4 counts were identified by the SEQUEST and X!TANDEM algorithms, filtered in SQL Server, before testing of frequency counts by Chi Square (χ
2 ), for analysis with the STRING algorithm, and comparison of precursor intensity by ANOVA in the R statistical system with the Tukey-Kramer Honestly Significant Difference (HSD) test., Results: Peptides and/or phosphopeptides of common plasma proteins such as HPR, HP, HPX, and SERPINA1 showed increased observation frequency and/or precursor intensity in ovarian cancer. Many cellular proteins showed large changes in frequency by Chi Square (χ2 > 60, p < 0.0001) in the ovarian cancer samples such as ZNF91, ZNF254, F13A1, LOC102723511, ZNF253, QSER1, P4HA1, GPC6, LMNB2, PYGB, NBR1, CCNI2, LOC101930455, TRPM5, IGSF1, ITGB1, CHD6, SIRT1, NEFM, SKOR2, SUPT20HL1, PLCE1, CCDC148, CPSF3, MORN3, NMI, XTP11, LOC101927572, SMC5, SEMA6B, LOXL3, SEZ6L2, and DHCR24. The protein gene symbols with large Chi Square values were significantly enriched in proteins that showed a complex set of previously established functional and structural relationships by STRING analysis. Analysis of the frequently observed proteins by ANOVA confirmed increases in mean precursor intensity in ZFN91, TRPM5, SIRT1, CHD6, RIMS1, LOC101930455 (XP_005275896), CCDC37 and GIMAP4 between ovarian cancer versus normal female and other diseases or controls by the Tukey-Kramer HSD test., Conclusion: Here we show that separation of endogenous peptides with a step gradient of organic/water and differential centrifugation followed by random and independent sampling by LC-ESI-MS/MS with analysis of peptide frequency and intensity by SQL Server and R revealed significant difference in the ex vivo cleavage of peptides between ovarian cancer and other clinical treatments. There was striking agreement between the proteins discovered from cancer plasma versus previous biomarkers discovered in tumors by genetic or biochemical methods. The results indicate that variation in plasma proteins from ovarian cancer may be directly discovered by LC-ESI-MS/MS that will be a powerful tool for clinical research.- Published
- 2018
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19. The plasma peptidome.
- Author
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Dufresne J, Bowden P, Thavarajah T, Florentinus-Mefailoski A, Chen ZZ, Tucholska M, Norzin T, Ho MT, Phan M, Mohamed N, Ravandi A, Stanton E, Slutsky AS, Dos Santos CC, Romaschin A, Marshall JC, Addison C, Malone S, Heyland D, Scheltens P, Killestein J, Teunissen C, Diamandis EP, Siu KWM, and Marshall JG
- Abstract
Background: It may be possible to discover new diagnostic or therapeutic peptides or proteins from blood plasma using LC-ESI-MS/MS to identify, with a linear quadrupole ion trap to identify, quantify and compare the statistical distributions of peptides cleaved ex vivo from plasma samples from different clinical populations., Methods: A systematic method for the organic fractionation of plasma peptides was applied to identify and quantify the endogenous tryptic peptides from human plasma from multiple institutions by C18 HPLC followed nano electrospray ionization and tandem mass spectrometry (LC-ESI-MS/MS) with a linear quadrupole ion trap. The endogenous tryptic peptides, or tryptic phospho peptides (i.e. without exogenous digestion), were extracted in a mixture of organic solvent and water, dried and collected by preparative C18. The tryptic peptides from 6 institutions with 12 different disease and normal EDTA plasma populations, alongside ice cold controls for pre-analytical variation, were characterized by mass spectrometry. Each patient plasma was precipitated in 90% acetonitrile and the endogenous tryptic peptides extracted by a stepwise gradient of increasing water and then formic acid resulting in 10 sub-fractions. The fractionated peptides were manually collected over preparative C18 and injected for 1508 LC-ESI-MS/MS experiments analyzed in SQL Server R., Results: Peptides that were cleaved in human plasma by a tryptic activity ex vivo provided convenient and sensitive access to most human proteins in plasma that show differences in the frequency or intensity of proteins observed across populations that may have clinical significance. Combination of step wise organic extraction of 200 μL of plasma with nano electrospray resulted in the confident identification and quantification ~ 14,000 gene symbols by X!TANDEM that is the largest number of blood proteins identified to date and shows that you can monitor the ex vivo proteolysis of most human proteins, including interleukins, from blood. A total of 15,968,550 MS/MS spectra ≥ E4 intensity counts were correlated by the SEQUEST and X!TANDEM algorithms to a federated library of 157,478 protein sequences that were filtered for best charge state (2+ or 3+) and peptide sequence in SQL Server resulting in 1,916,672 distinct best-fit peptide correlations for analysis with the R statistical system. SEQUEST identified some 140,054 protein accessions, or some ~ 26,000 gene symbols, proteins or loci, with at least 5 independent correlations. The X!TANDEM algorithm made at least 5 best fit correlations to more than 14,000 protein gene symbols with p-values and FDR corrected q-values of ~ 0.001 or less. Log
10 peptide intensity values showed a Gaussian distribution from E8 to E4 arbitrary counts by quantile plot, and significant variation in average precursor intensity across the disease and controls treatments by ANOVA with means compared by the Tukey-Kramer test. STRING analysis of the top 2000 gene symbols showed a tight association of cellular proteins that were apparently present in the plasma as protein complexes with related cellular components, molecular functions and biological processes., Conclusions: The random and independent sampling of pre-fractionated blood peptides by LC-ESI-MS/MS with SQL Server-R analysis revealed the largest plasma proteome to date and was a practical method to quantify and compare the frequency or log10 intensity of individual proteins cleaved ex vivo across populations of plasma samples from multiple clinical locations to discover treatment-specific variation using classical statistics suitable for clinical science. It was possible to identify and quantify nearly all human proteins from EDTA plasma and compare the results of thousands of LC-ESI-MS/MS experiments from multiple clinical populations using standard database methods in SQL Server and classical statistical strategies in the R data analysis system.- Published
- 2018
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20. Re-evaluation of the rabbit myosin protein standard used to create the empirical statistical model for decoy library searching.
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Dufresne J, Florentinus-Mefailoski A, Zhu PH, Bowden P, and Marshall JG
- Subjects
- Animals, Chromatography, Liquid methods, Immunoglobulin G chemistry, Models, Statistical, Peptides chemistry, Rabbits, Reference Standards, Spectrometry, Mass, Electrospray Ionization methods, Tandem Mass Spectrometry methods, Myosins chemistry, Myosins standards
- Abstract
A Rabbit myosin standard, like that used to create the empirical statistical model, was randomly and independently sampled by liquid chromatography micro electrospray ionization and tandem mass spectrometry (LC-ESI-MS/MS) with a linear quadrupole ion trap. The rabbit myosin protein standard appeared pure by SDS-PAGE and CBBR staining but showed many other proteins by silver staining. The LC-MS intensity from myosin and IgG samples were above the 99% safe limit of detection and quantification computed from 36 blank LC-ESI-MS/MS runs. The myosin contained ≤406 Gene Symbols, open reading frames or loci where 79 protein types showed ≥3 peptides from X!TANDEM. Myosins, actin, troponin, other proteins showed 95%-100% homology between the rabbit versus the human decoy library. The myosin protein complex from STRING was true positive compared to random or noise spectra MS/MS with a low type I error (p-value) and low FDR (q-value) computed in R. SDS-PAGE, Western blot, comparison to random and noise MS/MS spectra, X!TANDEM p-values, FDR corrected q-values, and STRING all agreed that the error rate of LC-ESI-MS/MS with a quadrupole ion trap is far below that assumed a priori by the design of the empirical statistical model for decoy library searching., (Copyright © 2018. Published by Elsevier Inc.)
- Published
- 2018
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21. A method for the extraction of the endogenous tryptic peptides (peptidome) from human EDTA plasma.
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Dufresne J, Florentinus-Mefailoski A, Bowden P, and Marshall JG
- Subjects
- Chromatography, High Pressure Liquid methods, Humans, Blood Proteins chemistry, Blood Proteins metabolism, Databases, Protein, Peptide Library, Spectrometry, Mass, Electrospray Ionization methods, Trypsin chemistry
- Abstract
The proteins identified from endogenous peptides agreed between serum versus plasma, and tryptic versus non-tryptic peptides, when collected by C18 alone and analyzed by liquid chromatography electrospray ionization and tandem mass spectrometry (LC-ESI-MS/MS) including amyloids, apolipoproteins, haptoglobin, complements, fibrinogens, hemopexin, antitrypsin and alpha 2 macroglobulin. Precipitation of polypeptides from plasma in 9 vol of 100% organic solvent followed by stepwise extraction of the insoluble pellet with an increasing fraction of water identified thousands of proteins. A Coomassie-blue protein binding assay, and tricine SDS-PAGE, showed that Acetonitrile-Water (AH) resulted in a greater relative enrichment of low molecular weight plasma polypeptides than Acetonitrile-Methanol Water (AMH). A total of 905,386 MS/MS spectra greater than ~10,000 (E4) counts were correlated by X!TANDEM to a federated human protein library of 153,124 different protein sequences that resulted in 58,223 fully tryptic peptides from 3463 Gene Symbols of which 1880 had ≥ 5 independent peptides (p ≤ 0.00001). The results were filtered and organized in an SQL database for analysis using the generic R statistical analysis system. Cellular proteins including secreted and exosome proteins, signaling factors, nucleic acid binding proteins, metabolic enzymes and uncharacterized factors were observed with a significant enrichment of expected protein-protein interactions by STRING analysis., (Copyright © 2018. Published by Elsevier Inc.)
- Published
- 2018
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22. Examining the role of MEDLINE as a patient care information resource: an analysis of data from the Value of Libraries study.
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Dunn K, Marshall JG, Wells AL, and Backus JEB
- Subjects
- Computer Literacy, Consumer Health Information statistics & numerical data, Female, Humans, Male, Periodicals as Topic, Databases, Bibliographic statistics & numerical data, Faculty, Medical, Libraries, Medical statistics & numerical data, MEDLINE statistics & numerical data
- Abstract
Objective: This study analyzed data from a study on the value of libraries to understand the specific role that the MEDLINE database plays in relation to other information resources that are available to health care providers and its role in positively impacting patient care., Methods: A previous study on the use of health information resources for patient care obtained 16,122 responses from health care providers in 56 hospitals about how providers make decisions affecting patient care and the role of information resources in that process. Respondents indicated resources used in answering a specific clinical question from a list of 19 possible resources, including MEDLINE. Study data were examined using descriptive statistics and regression analysis to determine the number of information resources used and how they were used in combination with one another., Results: Health care professionals used 3.5 resources, on average, to aid in patient care. The 2 most frequently used resources were journals (print and online) and the MEDLINE database. Using a higher number of information resources was significantly associated with a higher probability of making changes to patient care and avoiding adverse events. MEDLINE was the most likely to be among consulted resources compared to any other information resource other than journals., Conclusions: MEDLINE is a critical clinical care tool that health care professionals use to avoid adverse events, make changes to patient care, and answer clinical questions., Competing Interests: COMPETING INTERESTS Kathel Dunn and Joyce Backus are employed by the National Library of Medicine (NLM), the producer of the MEDLINE database. Joanne Gard Marshall and Amber L. Wells were paid through an interagency agreement between NLM and the US Department of Energy (DOE) with Oak Ridge Associated Universities (ORAU) for their participation in re-analyzing data from the original value of libraries study and for interpreting data and writing the current paper.
- Published
- 2017
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23. Nonsteroidal Anti-inflammatory Drugs for Managing Postoperative Endodontic Pain in Patients Who Present with Preoperative Pain: A Systematic Review and Meta-analysis.
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Smith EA, Marshall JG, Selph SS, Barker DR, and Sedgley CM
- Subjects
- Humans, Ibuprofen therapeutic use, Naproxen therapeutic use, Toothache drug therapy, Toothache surgery, Analgesics, Non-Narcotic therapeutic use, Anti-Inflammatory Agents, Non-Steroidal therapeutic use, Pain, Postoperative drug therapy, Root Canal Therapy adverse effects
- Abstract
Introduction: Nonsteroidal anti-inflammatory drugs (NSAIDs) have been commonly used to treat endodontic postoperative pain. The purpose of this study was to address the following Population, Intervention, Comparator, Outcome, Timing, Study design and setting question: in patients with preoperative pain who undergo initial orthograde endodontic treatment, what is the comparative efficacy of NSAIDS compared with non-narcotic analgesics or placebo in reducing postoperative pain and the incidence of adverse events., Methods: Ovid MEDLINE (1946-December 15, 2015), the Cochrane Database of Systematic Reviews (2005-December 15, 2015), and the Cochrane Central Register of Controlled Trials (to December 15, 2015) were searched using included drugs, indications, and study designs as search terms. Hand searches in texts were also conducted. Two independent reviewers assessed eligibility for inclusion, extracted data, and assessed quality using the risk of bias tool. L'Abbe plots were used for qualitative review. Where applicable, meta-analysis was conducted on the pooled effect size (ES)., Results: Two thousand two hundred eighty-four studies were identified through the database searches; 405 full-text articles were assessed. Fifteen articles met the inclusion criteria; qualitative analysis revealed all studies had a moderate to high risk of bias. Ibuprofen was the most studied NSAID. The L'Abbe plots showed that NSAIDS are effective at relieving postoperative endodontic pain overall. Meta-analysis showed that ibuprofen 600 mg is more effective than placebo at 6 hours postoperatively (ES = 10.50, P = .037), and ibuprofen 600 mg + acetaminophen 1000 mg combination is more effective than placebo (ES = 34.89, P = .000) but not significantly different than ibuprofen (ES = 13.94, P = .317). Five studies reported patients experiencing adverse events such as drowsiness, dizziness, nausea, and emesis; 2 studies reported that patients experienced no adverse events., Conclusions: A combination of ibuprofen 600 mg and acetaminophen 1000 mg is more effective than placebo but not significantly different than ibuprofen 600 mg at 6 hours postoperatively. Ibuprofen 600 mg is more effective than placebo at 6 hours postoperatively; however, there are insufficient data to recommend the most effective NSAID, dose amount, or dose interval for the relief of postoperative endodontic pain of longer duration in patients with preoperative pain., (Copyright © 2016 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.)
- Published
- 2017
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24. OxLDL receptor chromatography from live human U937 cells identifies SYK(L) that regulates phagocytosis of oxLDL.
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Howard JC, Florentinus-Mefailoski A, Bowden P, Trimble W, Grinstein S, and Marshall JG
- Subjects
- Chromatography, Liquid, Humans, Immunoglobulin G chemistry, Receptors, Fc chemistry, Receptors, Fc metabolism, Syk Kinase antagonists & inhibitors, Syk Kinase isolation & purification, Syk Kinase metabolism, Toll-Like Receptor 4 chemistry, Toll-Like Receptor 4 metabolism, U937 Cells, Lipoproteins, LDL chemistry, Phagocytosis, Receptors, Oxidized LDL chemistry, Syk Kinase chemistry
- Abstract
The binding and activation of macrophages by microscopic aggregates of oxLDL in the intima of the arteries may be an important step towards atherosclerosis leading to heart attack and stroke. Microbeads coated with oxLDL were used to activate, capture and isolate the oxLDL receptor complex from the surface of live cells. Analysis of the resulting tryptic peptides by liquid chromatography and tandem mass spectrometry revealed the Spleen Tyrosine Kinase (SYK), and many of SYK's known interaction network including Fc receptors (FCGR2A, FCER1G and FCGR1A) Toll receptor 4 (TLR4), receptor kinases like EGFRs, as well as RNA binding and metabolism proteins. High-intensity precursor ions (∼9*E3 to 2*E5 counts) were correlated to peptides and specific phosphopeptides from long isoform of SYK (SYK-L) by the SEQUEST, OMSSA and X!TANDEM algorithms. Peptides or phosphopeptides from SYK were observed with the oxLDL-microbeads. Pharmacological inhibitors of SYK activity significantly reduced the engulfment of oxLDL microbeads in the presence of serum factors, but had little effect on IgG phagocytosis. Anti SYK siRNA regulated oxLD engulfment in the context of serum factors and or SYK-L siRNA significantly inhibited engulfment of oxLDL microbeads, but not IgG microbeads., (Copyright © 2016 Elsevier Inc. All rights reserved.)
- Published
- 2016
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25. Linear quantification of a streptavidin-alkaline phosphatase probe for enzyme-linked immuno mass spectrometric assay.
- Author
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Florentinus-Mefailoski A and Marshall JG
- Subjects
- Alkaline Phosphatase analysis, Female, Humans, Male, Streptavidin analysis, Alkaline Phosphatase chemistry, Enzyme-Linked Immunosorbent Assay, Molecular Probes analysis, Molecular Probes chemistry, Prostate-Specific Antigen blood, Spectrometry, Mass, Electrospray Ionization methods, Streptavidin chemistry
- Abstract
The alkaline phosphatase-streptavidin (AP-SA) probe released adenosine (∼267.2 Da) from the substrate adenosine monophosphate (AMP), where a signal may be detected from as little as 0.5 μl of a 0.1-pg/ml dilution of the probe (2.6 × 10(-22) mol). The signal from the AP-SA probe was linear from 1 to 50 pg/ml by monitoring adenosine release at 268 m/z (M + H) with liquid chromatography, electrospray ionization, and quadrupole mass spectrometry (LC-ESI-MS). The safe limit of detection and quantification of the AP-SA probe was approximately 0.5 pg/well or 5 pg/ml. Enzyme-linked immuno mass spectrometric assay (ELIMSA) using the AP-SA probe provided a linear signal response for prostate-specific antigen (PSA) against external standards from 1 to 500 pg/ml. The ELIMSA showed a safe limit of detection and quantification at 5 pg PSA/well or 50 pg/ml (false positive detection rate P ≤ 0.01). Female samples of 100 μl plasma/well were read against standards and blanks made in normal female plasma, and the lowest sample quantified was approximately 9.8 pg/well or 98 pg/ml. Here ELIMSA was applied to measure PSA in plasma from female, normal male, prostatectomy patient, and cancer patient samples that showed significant differences by analysis of variance (ANOVA)., (Copyright © 2016. Published by Elsevier Inc.)
- Published
- 2016
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26. A phagocytosis assay for oxidized low-density lipoprotein versus immunoglobulin G-coated microbeads in human U937 macrophages.
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Vance DT, Dufresne J, Florentinus-Mefailoski A, Tucholska M, Trimble W, Grinstein S, and Marshall JG
- Subjects
- Chromatography, Liquid, Humans, Spectrometry, Mass, Electrospray Ionization, U937 Cells, Immunoglobulin G metabolism, Lipoproteins, LDL metabolism, Macrophages metabolism, Phagocytosis
- Abstract
The human monocyte cell line U937 was differentiated into an adherent macrophage phenotype using phorbol 12-myristate 13-acetate (PMA) to assay the phagocytosis of oxidized low-density lipoprotein (oxLDL) that may play a role in atherosclerosis. Microbeads were coated with the inflammatory ligand oxLDL to create a novel phagocytosis assay that models the binding of macrophages to oxLDL in the solid phase such as found in the fatty streaks of the arteries. The oxLDL was prepared with LDL from human ethylenediaminetetraacetic acid (EDTA) plasma oxidized with an excess (5 mM) of the strong oxidizing agent CuSO4 and characterized by sodium dodecyl sulfate-polyacrylamide gel electrophoresis with Western blot. The binding of the oxLDL to the beads was confirmed by DilC18-oxLDL staining and confocal microscopy in addition to trypsin digestion of the microbeads for liquid chromatography, electrospray ionization, and tandem mass spectrometry. Phagocytosis of the oxLDL versus human bulk immunoglobulin G1 (IgG1)-coated microbeads was assayed over time, in the presence and absence of serum factors, by pulse chase and with enzyme inhibitor treatments. The ligand beads were then stained with specific antibodies to oxLDL versus human IgG to differentially stain external versus engulfed ligand microbeads. The phagocytosis of oxLDL and IgG ligand microbeads was abolished by the actin polymerization inhibitors cytochalasin D and latrunculin. Pharmacological inhibitors of the receptor enzymes JAK, SRC, and PLC prevented both IgG and oxLDL receptor function. In contrast, the function of the oxLDL phagocytic receptor complex was more sensitive to inhibition of PTK2, PKC, and SYK activity., (Copyright © 2016 Elsevier Inc. All rights reserved.)
- Published
- 2016
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27. David Lawrence Sackett (born 17 November 1934; died 13 May 2015).
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Booth A and Marshall JG
- Subjects
- Aged, 80 and over, Humans, Male, Death, Epidemiology trends, Physicians trends
- Published
- 2015
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28. AMP-Activated Protein Kinase Regulates the Cell Surface Proteome and Integrin Membrane Traffic.
- Author
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Ross E, Ata R, Thavarajah T, Medvedev S, Bowden P, Marshall JG, and Antonescu CN
- Subjects
- Biotinylation, Biphenyl Compounds, Cell Adhesion drug effects, Cell Line, Cell Movement drug effects, Gene Expression Regulation, Humans, Mass Spectrometry, Protein Transport drug effects, Proteome drug effects, AMP-Activated Protein Kinases metabolism, Cell Membrane metabolism, Integrins metabolism, Proteome metabolism, Pyrones pharmacology, Thiophenes pharmacology
- Abstract
The cell surface proteome controls numerous cellular functions including cell migration and adhesion, intercellular communication and nutrient uptake. Cell surface proteins are controlled by acute changes in protein abundance at the plasma membrane through regulation of endocytosis and recycling (endomembrane traffic). Many cellular signals regulate endomembrane traffic, including metabolic signaling; however, the extent to which the cell surface proteome is controlled by acute regulation of endomembrane traffic under various conditions remains incompletely understood. AMP-activated protein kinase (AMPK) is a key metabolic sensor that is activated upon reduced cellular energy availability. AMPK activation alters the endomembrane traffic of a few specific proteins, as part of an adaptive response to increase energy intake and reduce energy expenditure. How increased AMPK activity during energy stress may globally regulate the cell surface proteome is not well understood. To study how AMPK may regulate the cell surface proteome, we used cell-impermeable biotinylation to selectively purify cell surface proteins under various conditions. Using ESI-MS/MS, we found that acute (90 min) treatment with the AMPK activator A-769662 elicits broad control of the cell surface abundance of diverse proteins. In particular, A-769662 treatment depleted from the cell surface proteins with functions in cell migration and adhesion. To complement our mass spectrometry results, we used other methods to show that A-769662 treatment results in impaired cell migration. Further, A-769662 treatment reduced the cell surface abundance of β1-integrin, a key cell migration protein, and AMPK gene silencing prevented this effect. While the control of the cell surface abundance of various proteins by A-769662 treatment was broad, it was also selective, as this treatment did not change the cell surface abundance of the transferrin receptor. Hence, the cell surface proteome is subject to acute regulation by treatment with A-769662, at least some of which is mediated by the metabolic sensor AMPK.
- Published
- 2015
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29. An enzyme-linked immuno-mass spectrometric assay with the substrate adenosine monophosphate.
- Author
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Florentinus-Mefailoski A, Soosaipillai A, Dufresne J, Diamandis EP, and Marshall JG
- Subjects
- Female, Humans, Kallikreins blood, Male, Prostate-Specific Antigen blood, Substrate Specificity, Adenosine Monophosphate chemistry, Alkaline Phosphatase chemistry, Enzyme-Linked Immunosorbent Assay methods, Kallikreins analysis, Prostate-Specific Antigen analysis, Spectrometry, Mass, Electrospray Ionization methods, Streptavidin chemistry
- Abstract
An enzyme-linked immuno-mass spectrometric assay (ELIMSA) with the specific detection probe streptavidin conjugated to alkaline phosphatase catalyzed the production of adenosine from the substrate adenosine monophosphate (AMP) for sensitive quantification of prostate-specific antigen (PSA) by mass spectrometry. Adenosine ionized efficiently and was measured to the femtomole range by dilution and direct analysis with micro-liquid chromatography, electrospray ionization, and mass spectrometry (LC-ESI-MS). The LC-ESI-MS assay for adenosine production was shown to be linear and accurate using internal (13)C(15)N adenosine isotope dilution, internal (13)C(15)N adenosine one-point calibration, and external adenosine standard curves with close agreement. The detection limits of LC-ESI-MS for alkaline phosphatase-streptavidin (AP-SA, ∼190,000 Da) was tested by injecting 0.1 μl of a 1 pg/ml solution, i.e., 100 attograms or 526 yoctomole (5.26E-22) of the alkaline-phosphatase labeled probe on column (about 315 AP-SA molecules). The ELIMSA for PSA was linear and showed strong signals across the picogram per milliliter range and could robustly detect PSA from all of the prostatectomy patients and all of the female plasma samples that ranged as low as 70 pg/ml with strong signals well separated from the background and well within the limit of quantification of the AP-SA probe. The results of the ELIMSA assay for PSA are normal and homogenous when independently replicated with a fresh standard over multiple days, and intra and inter diem assay variation was less than 10 % of the mean. In a blind comparison, ELIMSA showed excellent agreement with, but was more sensitive than, the present gold standard commercial fluorescent ELISA, or ECL-based detection, of PSA from normal and prostatectomy samples, respectively.
- Published
- 2015
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30. Pyridoxamine-5-phosphate enzyme-linked immune mass spectrometric assay substrate for linear absolute quantification of alkaline phosphatase to the yoctomole range applied to prostate specific antigen.
- Author
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Florentinus-Mefailoski A and Marshall JG
- Subjects
- Calibration, Limit of Detection, Pyridoxamine metabolism, Alkaline Phosphatase metabolism, Enzyme-Linked Immunosorbent Assay methods, Mass Spectrometry methods, Prostate-Specific Antigen metabolism, Pyridoxamine analogs & derivatives
- Abstract
There is a need to measure proteins that are present in concentrations below the detection limits of existing colorimetric approaches with enzyme-linked immunoabsorbent assays (ELISA). The powerful enzyme alkaline phosphatase conjugated to the highly specific bacterial protein streptavidin binds to biotinylated macromolecules like proteins, antibodies, or other ligands and receptors with a high affinity. The binding of the biotinylated detection antibody, with resulting amplification of the signal by the catalytic production of reporter molecules, is key to the sensitivity of ELISA. The specificity and amplification of the signal by the enzyme alkaline phosphatase in ELISA together with the sensitivity of liquid chromatography electrospray ionization and mass spectrometry (LC-ESI-MS) to detect femtomole to picomole amounts of reporter molecules results in an ultrasensitive enzyme-linked immune mass spectrometric assay (ELIMSA). The novel ELIMSA substrate pyridoxamine-5-phosphate (PA5P) is cleaved by the enzyme alkaline phosphatase to yield the basic and hydrophilic product pyridoxamine (PA) that elutes rapidly with symmetrical peaks and a flat baseline. Pyridoxamine (PA) and (13)C PA were both observed to show a linear relationship between log ion intensity and quantity from picomole to femtomole amounts by liquid chromatography-electrospray ionization and mass spectrometry. Four independent methods, (i) internal (13)C isotope PA dilution curves, (ii) internal (13)C isotope one-point calibration, (iii) external PA standard curve, and (iv) external (13)C PA standard curve, all agreed within 1 digit in the same order of magnitude on the linear quantification of PA. Hence, a mass spectrometer can be used to robustly detect 526 ymol of the alkaline phosphatase streptavidin probe and accurately quantify zeptomole amounts of PSA against log linear absolute standard by micro electrospray on a simple ion trap.
- Published
- 2014
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31. Enzyme linked immuno mass spectrometric assay (ELIMSA).
- Author
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Florentinus-Mefailoski A, Safi F, and Marshall JG
- Subjects
- Enzyme-Linked Immunosorbent Assay methods, Humans, Sensitivity and Specificity, Mass Spectrometry methods
- Abstract
A new technology termed ELIMSA combines the specificity and enzymatic amplification of Enzyme Linked Immunosorbent assay (ELISA) with the sensitivity and flexibility of mass spectrometry (MS). At present, substrates for the reporter enzymes horseradish peroxidase (HRP) or alkaline phosphatase (AP) yield colored, fluorescent or luminescent products. The central concept of ELIMSA is that the reporter enzymes HRP and AP yield products that ionize efficiently with a high signal to noise ratio that can be measured by mass spectrometry. The reporter enzymes HRP or AP may be covalently attached to a specific detection probe such as a protein or an antibody to bind their target analyte and then catalyze the rapid production of ionizable, small-molecules. The use of mass spectrometry to measure small molecule products may commonly reach femto to picomol amounts on the column with high signal to noise ratio. Mass spectrometry combined with the enzyme amplification in ELISA provides absolute sensitivity to detect attomol of PSA and was comparable to, or more sensitive, than radio immune assays and electrochemical detectors but with only existing reagents and equipment. ELIMSA permits monitoring of multiple substrates and products and provides comparison to absolute standards., Biological Significance: There is an urgent need to detect and quantify low abundance proteins such as hormones, chemokines, cytokines, and others that exist at attomolar concentrations under physiological conditions by ELIMSA. A sensitive method for the quantification of immunological assays is obtained by applying mass spectrometry to detect the products of the alkaline phosphatase (AP) and horseradish peroxidase (HRP) enzyme reactions. There are many molecules from human subjects or micro-organisms that are of great importance to medicine, industry, nutrition or the environment that need to be repeatedly analyzed and are often near to, or beyond, the edge of existing analytical technology. The presence of molecules in biological samples, industrial products or the environment may be detected by probes that bind to the target analyte. Combining the reporter enzymes from ELISA with sensitive liquid chromatography (LC), electrospray ionization (ESI) and tandem mass spectrometry (MS/MS) will permit the sensitive detection and quantification of the molecular probes by Enzyme Linked Immuno Mass Spectrometric Assay (ELIMSA). The flexibility and sensitivity of mass spectrometry to measure large numbers of compounds simultaneously should permit the quantification of multiple ELIMSA reactions at separate mass-to-charge (m/z) ratios. Hence ELIMSA and it variants should permit the rapid and simple detection and quantification of many molecules over the complete range of biologically important concentrations without the use of radiolabels using only existing antibodies, reagents and instruments. Antibodies coupled to reporter enzymes that are widely used in biomedical and environmental applications can now be detected and quantified using ultra sensitive mass spectrometry to create a sensitive and flexible ELIMSA system. Absolute standards of analytes or enzyme product may serve as a reference., (Copyright © 2013 Elsevier B.V. All rights reserved.)
- Published
- 2014
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32. Library and information services: impact on patient care quality.
- Author
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Marshall JG, Morgan JC, Thompson CA, and Wells AL
- Subjects
- Canada, Evidence-Based Medicine, Hospital Bed Capacity, Humans, Library Services statistics & numerical data, Medical Errors prevention & control, Time Factors, United States, Information Services statistics & numerical data, Patient Care methods, Quality of Health Care organization & administration
- Abstract
Purpose: The purpose of this paper is to explore library and information service impact on patient care quality., Design/methodology/approach: A large-scale critical incident survey of physicians and residents at 56 library sites serving 118 hospitals in the USA and Canada. Respondents were asked to base their answers on a recent incident in which they had used library resources to search for information related to a specific clinical case., Findings: Of 4,520 respondents, 75 percent said that they definitely or probably handled patient care differently using information obtained through the library. In a multivariate analysis, three summary clinical outcome measures were used as value and impact indicators: first, time saved; second, patient care changes; and third, adverse events avoided. The outcomes were examined in relation to four information access methods: first, asking librarian for assistance; second, performing search in a physical library; third, searching library's web site; or fourth, searching library resources on an institutional intranet. All library access methods had consistently positive relationships with the clinical outcomes, providing evidence that library services have a positive impact on patient care quality., Originality/value: Electronic collections and services provided by the library and the librarian contribute to patient care quality.
- Published
- 2014
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33. Linking research to practice: the rise of evidence-based health sciences librarianship.
- Author
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Marshall JG
- Subjects
- Humans, Libraries, Medical, Professional Role, Evidence-Based Practice, Library Science trends
- Abstract
Purpose: The lecture explores the origins of evidence-based practice (EBP) in health sciences librarianship beginning with examples from the work of Janet Doe and past Doe lecturers. Additional sources of evidence are used to document the rise of research and EBP as integral components of our professional work., Methods: FOUR SOURCES OF EVIDENCE ARE USED TO EXAMINE THE RISE OF EBP: (1) a publication by Doe and research-related content in past Doe lectures, (2) research-related word usage in articles in the Bulletin of the Medical Library Association and Journal of the Medical Library Association between 1961 and 2010, (3) Medical Library Association activities, and (4) EBP as an international movement., Results: These sources of evidence confirm the rise of EBP in health sciences librarianship. International initiatives sparked the rise of evidence-based librarianship and continue to characterize the movement. This review shows the emergence of a unique form of EBP that, although inspired by evidence-based medicine (EBM), has developed its own view of evidence and its application in library and information practice., Implications: Health sciences librarians have played a key role in initiating, nurturing, and spreading EBP in other branches of our profession. Our close association with EBM set the stage for developing our own EBP. While we relied on EBM as a model for our early efforts, we can observe the continuing evolution of our own unique approach to using, creating, and applying evidence from a variety of sources to improve the quality of health information services.
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- 2014
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34. The value of library and information services in patient care: results of a multisite study.
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Marshall JG, Sollenberger J, Easterby-Gannett S, Morgan LK, Klem ML, Cavanaugh SK, Oliver KB, Thompson CA, Romanosky N, and Hunter S
- Subjects
- Adult, Data Collection, Female, Focus Groups, Humans, Information Seeking Behavior, Interviews as Topic, Male, Middle Aged, Physicians, Information Services standards, Library Services standards, Patient Care
- Abstract
Objective: The research conducted a large-scale, multisite study on the value and impact of library and information services on patient care., Methods: THE STUDY USED: (1) 2 initial focus groups of librarians; (2) a web-based survey of physicians, residents, and nurses at 56 library sites serving 118 hospitals; and (3) 24 follow-up telephone interviews. Survey respondents were asked to base their responses on a recent incident in which they had sought information for patient care., Results: Of the 16,122 survey respondents, 3/4 said that they had definitely or probably handled aspects of the patient care situation differently as a result of the information. Among the reported changes were advice given to the patient (48%), diagnosis (25%), and choice of drugs (33%), other treatment (31%), and tests (23%). Almost all of the respondents (95%) said the information resulted in a better informed clinical decision. Respondents reported that the information allowed them to avoid the following adverse events: patient misunderstanding of the disease (23%), additional tests (19%), misdiagnosis (13%), adverse drug reactions (13%), medication errors (12%), and patient mortality (6%)., Conclusions: Library and information resources were perceived as valuable, and the information obtained was seen as having an impact on patient care.
- Published
- 2013
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35. Quantitative statistical analysis of standard and human blood proteins from liquid chromatography, electrospray ionization, and tandem mass spectrometry.
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Bowden P, Thavarajah T, Zhu P, McDonell M, Thiele H, and Marshall JG
- Subjects
- Chromatography, Liquid statistics & numerical data, Humans, Proteomics statistics & numerical data, Spectrometry, Mass, Electrospray Ionization statistics & numerical data, Statistics as Topic, Tandem Mass Spectrometry, Blood Proteins analysis, Chromatography, Liquid methods, Proteomics methods, Spectrometry, Mass, Electrospray Ionization methods
- Abstract
It will be important to determine if the parent and fragment ion intensity results of liquid chromatography, electrospray ionization and tandem mass spectrometry (LC-ESI-MS/MS) experiments have been randomly and independently sampled from a normal population for the purpose of statistical analysis by general linear models and ANOVA. The tryptic parent peptide and fragment ion m/z and intensity data in the mascot generic files from LC-ESI-MS/MS of purified standard proteins, and human blood protein fractionated by partition chromatography, were parsed into a Structured Query Language (SQL) database and were matched with protein and peptide sequences provided by the X!TANDEM algorithm. The many parent and/or fragment ion intensity values were log transformed, tested for normality, and analyzed using the generic Statistical Analysis System (SAS). Transformation of both parent and fragment intensity values by logarithmic functions yielded intensity distributions that closely approximate the log-normal distribution. ANOVA models of the transformed parent and fragment intensity values showed significant effects of treatments, proteins, and peptides, as well as parent versus fragment ion types, with a low probability of false positive results. Transformed parent and fragment intensity values were compared over all sample treatments, proteins or peptides by the Tukey-Kramer Honestly Significant Difference (HSD) test. The approach provided a complete and quantitative statistical analysis of LC-ESI-MS/MS data from human blood.
- Published
- 2012
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36. Identification and quantification of peptides and proteins secreted from prostate epithelial cells by unbiased liquid chromatography tandem mass spectrometry using goodness of fit and analysis of variance.
- Author
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Florentinus AK, Bowden P, Sardana G, Diamandis EP, and Marshall JG
- Subjects
- 14-3-3 Proteins metabolism, Algorithms, Analysis of Variance, False Positive Reactions, Humans, Ions, Male, Models, Statistical, Reproducibility of Results, Software, Chromatography, Liquid methods, Epithelial Cells metabolism, Peptides chemistry, Prostate metabolism, Tandem Mass Spectrometry methods
- Abstract
The proteins secreted by prostate cancer cells (PC3(AR)6) were separated by strong anion exchange chromatography, digested with trypsin and analyzed by unbiased liquid chromatography tandem mass spectrometry with an ion trap. The spectra were matched to peptides within proteins using a goodness of fit algorithm that showed a low false positive rate. The parent ions for MS/MS were randomly and independently sampled from a log-normal population and therefore could be analyzed by ANOVA. Normal distribution analysis confirmed that the parent and fragment ion intensity distributions were sampled over 99.9% of their range that was above the background noise. Arranging the ion intensity data with the identified peptide and protein sequences in structured query language (SQL) permitted the quantification of ion intensity across treatments, proteins and peptides. The intensity of 101,905 fragment ions from 1421 peptide precursors of 583 peptides from 233 proteins separated over 11 sample treatments were computed together in one ANOVA model using the statistical analysis system (SAS) prior to Tukey-Kramer honestly significant difference (HSD) testing. Thus complex mixtures of proteins were identified and quantified with a high degree of confidence using an ion trap without isotopic labels, multivariate analysis or comparing chromatographic retention times., (Copyright © 2011 Elsevier B.V. All rights reserved.)
- Published
- 2012
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37. A dominantly acting murine allele of Mcm4 causes chromosomal abnormalities and promotes tumorigenesis.
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Bagley BN, Keane TM, Maklakova VI, Marshall JG, Lester RA, Cancel MM, Paulsen AR, Bendzick LE, Been RA, Kogan SC, Cormier RT, Kendziorski C, Adams DJ, and Collier LS
- Subjects
- Alleles, Animals, Chromosomal Instability, DNA Helicases metabolism, DNA Replication, Disease Models, Animal, Genes, Dominant, Humans, Mice, Minichromosome Maintenance Complex Component 4, Mutation, Receptor, Notch1 genetics, Receptor, Notch1 metabolism, Reticulocytes cytology, Reticulocytes metabolism, Saccharomyces cerevisiae genetics, Saccharomyces cerevisiae metabolism, Cell Transformation, Neoplastic genetics, Chromosome Aberrations, DNA Helicases genetics, Precursor T-Cell Lymphoblastic Leukemia-Lymphoma genetics
- Abstract
Here we report the isolation of a murine model for heritable T cell lymphoblastic leukemia/lymphoma (T-ALL) called Spontaneous dominant leukemia (Sdl). Sdl heterozygous mice develop disease with a short latency and high penetrance, while mice homozygous for the mutation die early during embryonic development. Sdl mice exhibit an increase in the frequency of micronucleated reticulocytes, and T-ALLs from Sdl mice harbor small amplifications and deletions, including activating deletions at the Notch1 locus. Using exome sequencing it was determined that Sdl mice harbor a spontaneously acquired mutation in Mcm4 (Mcm4(D573H)). MCM4 is part of the heterohexameric complex of MCM2-7 that is important for licensing of DNA origins prior to S phase and also serves as the core of the replicative helicase that unwinds DNA at replication forks. Previous studies in murine models have discovered that genetic reductions of MCM complex levels promote tumor formation by causing genomic instability. However, Sdl mice possess normal levels of Mcms, and there is no evidence for loss-of-heterozygosity at the Mcm4 locus in Sdl leukemias. Studies in Saccharomyces cerevisiae indicate that the Sdl mutation produces a biologically inactive helicase. Together, these data support a model in which chromosomal abnormalities in Sdl mice result from the ability of MCM4(D573H) to incorporate into MCM complexes and render them inactive. Our studies indicate that dominantly acting alleles of MCMs can be compatible with viability but have dramatic oncogenic consequences by causing chromosomal abnormalities., Competing Interests: The authors have declared that no competing interests exist.
- Published
- 2012
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38. Clinical proteomics.
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Végvári A, Kondo T, and Marshall JG
- Published
- 2012
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39. The Fc receptor-cytoskeleton complex from human neutrophils.
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Florentinus AK, Jankowski A, Petrenko V, Bowden P, and Marshall JG
- Subjects
- Actins metabolism, Humans, Microspheres, Phagocytosis physiology, Protein Interaction Maps, Spectrometry, Mass, Electrospray Ionization, Cytoskeletal Proteins analysis, Cytoskeleton metabolism, Immunoglobulin G metabolism, Neutrophils metabolism, Receptors, Fc metabolism
- Abstract
The Fc receptor complex and its associated phagocytic cytoskeleton machinery were captured from the surface of live cells by IgG coated microbeads and identified by mass spectrometry. The random and independently sampled intensity values of peptides were similar in the control and IgG samples. After log transformation, the parent and fragment intensity values showed a normal distribution where ≥99.9% of the data was well above the background noise. Some proteins showed significant differences in intensity between the IgG and control samples by ANOVA followed by the Tukey-Kramer honestly significant difference test. However many proteins were specific to the IgG beads or the control beads. The set of detected cytoskeleton proteins, binding proteins and enzymes detected on the IgG beads were used to predict the network of actin-associated regulatory factors. Signaling factors/proteins such as PIK3, PLC, GTPases (such CDC42, Rho GAPs/GEFs), annexins and inositol triphosphate receptors were all identified as being specific to the activated receptor complex by mass spectrometry. In addition, the tyrosine kinase Fak was detected with the IgG coated beads. Hence, an activated receptor cytoskeleton complex and its associated regulatory proteins were captured from the surface of live human primary leukocytes., (Copyright © 2011 Elsevier B.V. All rights reserved.)
- Published
- 2011
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40. Mass spectrometry of peptides and proteins from human blood.
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Zhu P, Bowden P, Zhang D, and Marshall JG
- Subjects
- Blood Proteins metabolism, Databases, Protein, Endopeptidases chemistry, Humans, Mass Spectrometry instrumentation, Proteolysis, Reference Standards, Sensitivity and Specificity, Specimen Handling, Blood Proteins isolation & purification, Mass Spectrometry methods, Protein Processing, Post-Translational
- Abstract
It is difficult to convey the accelerating rate and growing importance of mass spectrometry applications to human blood proteins and peptides. Mass spectrometry can rapidly detect and identify the ionizable peptides from the proteins in a simple mixture and reveal many of their post-translational modifications. However, blood is a complex mixture that may contain many proteins first expressed in cells and tissues. The complete analysis of blood proteins is a daunting task that will rely on a wide range of disciplines from physics, chemistry, biochemistry, genetics, electromagnetic instrumentation, mathematics and computation. Therefore the comprehensive discovery and analysis of blood proteins will rank among the great technical challenges and require the cumulative sum of many of mankind's scientific achievements together. A variety of methods have been used to fractionate, analyze and identify proteins from blood, each yielding a small piece of the whole and throwing the great size of the task into sharp relief. The approaches attempted to date clearly indicate that enumerating the proteins and peptides of blood can be accomplished. There is no doubt that the mass spectrometry of blood will be crucial to the discovery and analysis of proteins, enzyme activities, and post-translational processes that underlay the mechanisms of disease. At present both discovery and quantification of proteins from blood are commonly reaching sensitivities of ∼1 ng/mL., (Copyright © 2010 Wiley Periodicals, Inc.)
- Published
- 2011
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41. Peptide-to-protein distribution versus a competition for significance to estimate error rate in blood protein identification.
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Zhu P, Bowden P, Tucholska M, Zhang D, and Marshall JG
- Subjects
- Algorithms, Amino Acid Sequence, Animals, Databases, Protein, Humans, Molecular Sequence Data, Zebrafish, Blood Proteins chemistry, Chromatography, High Pressure Liquid methods, Peptides chemistry, Spectrometry, Mass, Electrospray Ionization methods
- Abstract
The simplest model-that authentic tandem mass spectrometry (MS/MS) spectra are no different from noise, random spectra, or false-positive results-may be directly examined by chi-square comparison of the peptide-to-protein distribution. The peptide-to-protein distribution of a set of 4151 redundant blood proteins identified by X!TANDEM indicated that there is a low probability that the authentic data were the same as noise, random spectra, or false-positive correlations (P<0.0001). In contrast, a competition for significance failed to distinguish approximately 90% of authentic blood proteins from those of noise, random spectra, or false-positive results (P<0.01) and apparently incurred a large type II error (false negative). The chi-square test of peptide-to-protein frequency distributions was found to be an efficient means to distinguish authentic data from false-positive results. Frequency-based statistics unambiguously demonstrated that proteins can be identified by liquid chromatography-electrospray ionization-MS/MS from human blood with acceptable confidence. Thus, the chi-square fit of the peptide-to-protein distribution could distinguish authentic data from random or false-positive data, but the score distribution method could not separate real results from false results., (Copyright © 2010 Elsevier Inc. All rights reserved.)
- Published
- 2011
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42. Comparison of intracanal EndoSequence Root Repair Material and ProRoot MTA to induce pH changes in simulated root resorption defects over 4 weeks in matched pairs of human teeth.
- Author
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Hansen SW, Marshall JG, and Sedgley CM
- Subjects
- Aluminum Compounds chemistry, Calcium Compounds chemistry, Calcium Hydroxide chemistry, Calcium Hydroxide therapeutic use, Calcium Phosphates chemistry, Case-Control Studies, Dental Pulp Cavity metabolism, Dentin metabolism, Diffusion, Drug Combinations, Humans, Hydrogen-Ion Concentration, Hydroxides metabolism, Materials Testing, Oxides chemistry, Root Canal Filling Materials chemistry, Root Canal Irrigants therapeutic use, Root Canal Preparation methods, Root Resorption physiopathology, Silicates chemistry, Sodium Chloride, Sodium Hypochlorite therapeutic use, Tantalum chemistry, Time Factors, Zirconium chemistry, Aluminum Compounds therapeutic use, Calcium Compounds therapeutic use, Calcium Phosphates therapeutic use, Oxides therapeutic use, Root Canal Filling Materials therapeutic use, Root Resorption therapy, Silicates therapeutic use, Tantalum therapeutic use, Zirconium therapeutic use
- Abstract
Introduction: Intracanal mineral trioxide aggregate (MTA) may provide an alternative to calcium hydroxide in the treatment of external inflammatory root resorption. This in vitro study using human matched pairs of teeth compared white ProRoot MTA (WMTA; (Dentsply Tulsa Dental Specialties, Tulsa, OK) and an alternative material with purportedly improved handling properties, EndoSequence Root Repair Material (ES; Brasseler USA, Savannah, GA), by measuring pH in simulated root surface resorptive defects after intracanal placement. The null hypothesis tested was that there is no difference between WMTA and ES., Methods: Bilaterally matched pairs (n = 24) of extracted, human, single-rooted teeth were instrumented to apical size 50/.06, and root surface cavities were prepared at 5 mm and 2 mm from the apex. Root canals of experimental matched pairs (n = 20) were filled with WMTA or ES; control pairs (n = 4) were filled with calcium hydroxide (positive control [POS]) or saline (negative control [NEG]). Teeth were sealed coronally and apically and immersed in saline. The pH in root surface cavities was measured at 20 minutes, 3 hours, 24 hours, 1 week, 2 weeks, 3 weeks, and 4 weeks., Results: The pH at 5 mm when compared with the 2-mm level was significantly higher for the WMTA, ES, and POS groups (P < .05, paired t tests); therefore, each level was analyzed separately. At both the 2-mm and 5-mm levels, significant pH changes occurred over time in the WMTA, ES (both P < .0001, repeated-measures analysis of variance), and POS (P < .0001, Friedman test) groups and not in the NEG group (mean pH = 7.32 ± 0.04, P > .05). There were no differences between WMTA and ES at 20 minutes and 3 hours at both levels or at 24 hours at 5mm. The pH of WMTA was higher than ES by 24 hours at the 2-mm level (8.79 vs 8.56, P < .05, paired t test) and after 1 week at the 5-mm level (8.91 vs 8.05, P < .0001) and was thereafter always significantly higher in WMTA compared with ES (P < .0001). The null hypothesis was rejected., Conclusions: In matched pairs of teeth, intracanal placement of WMTA compared with ES resulted in a higher pH in simulated root resorption defects that was time and root level dependent., (Copyright © 2011 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.)
- Published
- 2011
- Full Text
- View/download PDF
43. Chi-square comparison of tryptic peptide-to-protein distributions of tandem mass spectrometry from blood with those of random expectation.
- Author
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Zhu P, Bowden P, Tucholska M, and Marshall JG
- Subjects
- Algorithms, Chromatography, Liquid, False Positive Reactions, Humans, Proteome analysis, Proteomics methods, Spectrometry, Mass, Electrospray Ionization, Blood Proteins analysis, Peptides analysis, Proteins analysis, Tandem Mass Spectrometry methods
- Abstract
Proteomics uses tandem mass spectrometers and correlation algorithms to match peptides and their fragment spectra to amino acid sequences. The replication of multiple liquid chromatography experiments with electrospray ionization of peptides and tandem mass spectrometry (LC-ESI-MS/MS) produces large sets of MS/MS spectra. There is a need to assess the quality of large sets of experimental results by statistical comparison with that of random expectation. Classical frequency-based statistics such as goodness-of-fit tests for peptide-to-protein distributions could be used to calculate the probability that an entire set of experimental results has arisen by random chance. The frequency distributions of authentic MS/MS spectra from human blood were compared with those of false positive MS/MS spectra generated by a computer, or instrument noise, using the chi-square test. Here the mechanics of the chi-square test to compare the results in toto from a set of LC-ESI-MS/MS experiments with those of random expectation is detailed. The chi-square analysis of authentic spectra demonstrates unambiguously that the analysis of blood proteins separated by partition chromatography prior to tryptic digestions has a low probability that the cumulative peptide-to-protein distribution is the same as that of random or noise false positive spectra., (Copyright © 2010 Elsevier Inc. All rights reserved.)
- Published
- 2011
- Full Text
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44. The endogenous peptides of normal human serum extracted from the acetonitrile-insoluble precipitate using modified aqueous buffer with analysis by LC-ESI-Paul ion trap and Qq-TOF.
- Author
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Tucholska M, Florentinus A, Williams D, and Marshall JG
- Subjects
- Algorithms, Amino Acid Sequence, Chromatography methods, Electrophoresis, Polyacrylamide Gel, Humans, Ions, Molecular Sequence Data, Proteome, Acetonitriles chemistry, Blood Proteins chemistry, Chromatography, Liquid methods, Peptides chemistry, Proteomics methods, Spectrometry, Mass, Electrospray Ionization methods
- Abstract
Many peptides of biological or medicinal importance may be derived from proteolytic actions and are found at low concentrations in human blood fluids. Endogenous polypeptides from human serum were precipitated in acetonitrile and the precipitate was then selectively extracted with water modified by organic solvents and collected over C18 resin. Extraction of serum with C18 alone, and the acetonitrile supernatant or ultrafiltration collected over C18, served as controls. The samples were analyzed by SDS-PAGE, or C18 high pressure liquid chromatography with electrospray ionization using a Paul ion trap and Qq-TOF. Spectra were correlated without specifying an enzyme using the X!TANDEM or the Paragon algorithms. Multiple endogenous peptides from plasminogen, coagulation factors, collagens, serum amyloid, receptors, zinc finger/bromo peptide proteins, ryanodine receptor, calmodulin binding activator, erythroid differentiation factor, testes cancer antigen, extracellular matrix protein, myeloid/lymphoid leukemia 2 and many low abundance proteins were correlated by X!TANDEM with protein expect values of approximately E-16 or less. Proteins with binding sites for nucleic acids, phosphoinositides, and other cellular locations were also observed using the Qq-TOF and Paragon algorithm. Proteins with low expectation scores and overlapping peptides sequences were observed. The existence of these proteins in serum has been confirmed by tryptic digestion and LC-ESI-MS/MS. The presence of plasminogen, serum amyloid and zinc finger RNA binding proteins were confirmed by Western blot. There was agreement on the detection of endogenous peptides from low abundance proteins associated with the biology of cancer from the examination of the blood peptides by ion trap and Qq-TOF, tryptic digests of blood proteins, and Western blot., (Copyright 2010. Published by Elsevier B.V.)
- Published
- 2010
- Full Text
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45. Meta sequence analysis of human blood peptides and their parent proteins.
- Author
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Bowden P, Pendrak V, Zhu P, and Marshall JG
- Subjects
- Algorithms, Chromatography, Liquid methods, False Negative Reactions, False Positive Reactions, Humans, Models, Statistical, Peptides chemistry, Proteins chemistry, Proteome, Spectrometry, Mass, Electrospray Ionization methods, Tandem Mass Spectrometry methods, Trypsin chemistry, Blood Proteins chemistry, Proteomics methods
- Abstract
Sequence analysis of the blood peptides and their qualities will be key to understanding the mechanisms that contribute to error in LC-ESI-MS/MS. Analysis of peptides and their proteins at the level of sequences is much more direct and informative than the comparison of disparate accession numbers. A portable database of all blood peptide and protein sequences with descriptor fields and gene ontology terms might be useful for designing immunological or MRM assays from human blood. The results of twelve studies of human blood peptides and/or proteins identified by LC-MS/MS and correlated against a disparate array of genetic libraries were parsed and matched to proteins from the human ENSEMBL, SwissProt and RefSeq databases by SQL. The reported peptide and protein sequences were organized into an SQL database with full protein sequences and up to five unique peptides in order of prevalence along with the peptide count for each protein. Structured query language or BLAST was used to acquire descriptive information in current databases. Sampling error at the level of peptides is the largest source of disparity between groups. Chi Square analysis of peptide to protein distributions confirmed the significant agreement between groups on identified proteins., (Copyright 2010. Published by Elsevier B.V.)
- Published
- 2010
- Full Text
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46. Precipitation and selective extraction of human serum endogenous peptides with analysis by quadrupole time-of-flight mass spectrometry reveals posttranslational modifications and low-abundance peptides.
- Author
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Williams D, Ackloo S, Zhu P, Bowden P, Evans KR, Addison CL, Lock C, and Marshall JG
- Subjects
- Amino Acid Sequence, Chemical Precipitation, Electrophoresis, Polyacrylamide Gel, Humans, Molecular Sequence Data, Peptides analysis, Sensitivity and Specificity, Spectrometry, Mass, Electrospray Ionization methods, Tandem Mass Spectrometry methods, Peptides blood, Peptides metabolism, Protein Processing, Post-Translational, Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization methods
- Abstract
The endogenous peptides of human serum may have regulatory functions, have been associated with physiological states, and their modifications may reveal some mechanisms of disease. In order to correlate levels of specific peptides with disease alongside internal standards, the polypeptides must first be reliably extracted and identified. Endogenous blood peptides can be effectively enriched by precipitation of the serum with organic solvents followed by selective extraction of peptides using aqueous solutions modified with organic solvents. Polypeptides on filter paper were assayed with Coomasie brilliant blue binding. The polypeptides were resolved by detergent tricine polyacrylamide electrophoresis and visualized by diamine silver staining. Peptides in the extracts were collected by C18 and analyzed by matrix-assisted laser desorption/ionization and liquid chromatography-electrospray ionization-tandem mass spectrometry (MS/MS) quadrupole time-of-flight MS/MS. Peptides were resolved as multiple isotopic peaks in MS mode with mass deviation of 0.1 Da or less and similar accuracy for fragments. The sensitivity of MS and MS/MS analysis was estimated to be in the picomolar range or less. The peptide composition of the extracts was dependent on solvent formulation. Multiple peptides from apolipoproteins, complement proteins, coagulation factors, and many others were identified by X!Tandem with high mass accuracy of peptide ions and fragments from collision-induced dissociation. Many previously unreported posttranslational modifications of peptides including phosphorylations, oxidations, glycosylations, and others were detected with high mass accuracy and may be of clinical importance. About 4,630 redundant peptides were identified with 99% confidence separately, and together some 1,251 distinct proteins were identified with 99% confidence or greater using the Paragon algorithm.
- Published
- 2010
- Full Text
- View/download PDF
47. Regional variations in cancer screening rates found in women with diabetes.
- Author
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Marshall JG, Cowell JM, Campbell ES, and McNaughton DB
- Subjects
- Adult, Aged, Behavioral Risk Factor Surveillance System, Breast Neoplasms prevention & control, Comorbidity, Diabetes Mellitus, Type 2 prevention & control, Female, Health Knowledge, Attitudes, Practice, Humans, Logistic Models, Middle Aged, Patient Acceptance of Health Care psychology, Risk Factors, Sickness Impact Profile, Socioeconomic Factors, United States epidemiology, Uterine Cervical Neoplasms prevention & control, Women's Health, Breast Neoplasms epidemiology, Diabetes Mellitus, Type 2 epidemiology, Mammography statistics & numerical data, Mass Screening statistics & numerical data, Patient Acceptance of Health Care statistics & numerical data, Uterine Cervical Neoplasms epidemiology
- Abstract
Background: A review of the literature gives conflicting findings regarding gender-specific cancer screening rates found in women with chronic illness., Objectives: The purpose of this study was to determine if women with diabetes have different patterns of cancer screening than women of the general population, and if so, to identify the determinants of these screening patterns guided by the Predisposing, Reinforcing, and Enabling Constructs in Educational Diagnosis and Evaluation (PRECEDE) model., Methods: The 12 states using the optional women's health module for the 2003 Behavioral Risk Factor Surveillance System were downloaded into the STATA software. Contingency tables were used to identify the prevalence of cancer screening in women who self-report that they have diabetes in comparison with women who report being nondiabetic. Logistic regression was used to examine the association between the PRECEDE model determinants and the screening behaviors., Results: No significant association was found between having a diagnosis of diabetes and having mammography screening rates (F = 1.5, p =.22). However, cervical cancer screening rates were statistically significantly different between the two groups of women (F = 39.01, p <.01). A gap in cervical cancer screening rates was identified among women with diabetes as compared with women without diabetes (78% versus 86%, respectively). Regional exceptions were noted between the 12 states. Ten of the 11 PRECEDE variables demonstrated a significant association with Papanicolaou test screening rates. The states demonstrating inadequate screening rates were the states with the most negative PRECEDE factors., Discussion: Research has shown that the primary reason women seek cancer screening is when they are encouraged by a healthcare provider. If other care providers are focused on disease management, nurses who provide holistic care can build on the advocacy role inherent in nursing and encourage screening in underserved areas of the country.
- Published
- 2010
- Full Text
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48. Measuring the value and impact of health sciences libraries: planning an update and replication of the Rochester Study.
- Author
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Dunn K, Brewer K, Marshall JG, and Sollenberger J
- Subjects
- Library Associations, Library Services, Planning Techniques, Research Design, United States, Libraries, Medical, Outcome Assessment, Health Care methods
- Published
- 2009
- Full Text
- View/download PDF
49. An in vivo comparison of the Root ZX II, the Apex NRG XFR, and Mini Apex Locator by using rotary nickel-titanium files.
- Author
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Siu C, Marshall JG, and Baumgartner JC
- Subjects
- Adult, Aged, Dental Alloys, Electric Impedance, Electrical Equipment and Supplies, Humans, Middle Aged, Nickel, Stainless Steel, Titanium, Dental Instruments, Dental Pulp Cavity anatomy & histology, Root Canal Preparation instrumentation, Tooth Apex anatomy & histology
- Abstract
Introduction: The purpose of this study was to compare the accuracy of working length (WL) measurements by using the Root ZX II, Apex NRG XFR, and Mini Apex Locator with rotary nickel-titanium (NiTi) instruments., Methods: Twenty-eight teeth had their WLs determined with each electronic apex locator (EAL) by using 0.04 taper ProFiles sizes 40-20 in a crown-down technique until WL was reached. Four control teeth had their WL determined by using stainless steel hand files. The files were cemented at WL, and the teeth were extracted. The apical 4 mm of each root was shaved to the apical constriction, exposing the file. Photographs were taken under 15x and 30x magnification and projected at 360x and 720x for evaluation., Results: The accuracy of the Root ZX II, Apex NRG XFR, and Mini Apex Locator in locating the minor diameter within +/-0.5 mm was 50%, 46.43%, and 39.29%, respectively. There was no statistically significant difference between the EALs in locating the minor diameter. The determination of WL by using hand files in the control teeth was more accurate., Conclusions: The Root ZX II, Apex NRG XFR, and Mini Apex Locator used with rotary NiTi files were able to locate the apical constriction within +/-0.5 mm only 50% or less of the time.
- Published
- 2009
- Full Text
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50. Future of academic and health libraries: personal perspectives.
- Author
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Haines M and Marshall JG
- Subjects
- Anecdotes as Topic, Humans, Interprofessional Relations, Professional Role, United Kingdom, Information Dissemination methods, Information Storage and Retrieval methods, Librarians, Libraries, Medical organization & administration, Library Services organization & administration
- Published
- 2008
- Full Text
- View/download PDF
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