82 results on '"David D. Peterson"'
Search Results
2. ELECTROMYOGRAPHY (EMG) COMPARISON OF FOUR DIFFERENT BACK EXTENSION DEVICES
- Author
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Matt Beerse and David D. Peterson
- Subjects
medicine.medical_specialty ,Physical medicine and rehabilitation ,medicine.diagnostic_test ,Computer science ,General Engineering ,medicine ,Extension (predicate logic) ,Electromyography - Published
- 2021
3. Comparing Alternate Percent Body Fat Estimation Techniques for United States Navy Body Composition Assessment
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David D. Peterson, Austin W. Latour, and Daniel D. Riner
- Subjects
Navy ,Military personnel ,Aeronautics ,Body height ,Environmental science ,Fitness Testing ,Mandate ,ComputingMilieux_LEGALASPECTSOFCOMPUTING ,ComputerApplications_COMPUTERSINOTHERSYSTEMS ,Body weight ,Circumference measurements - Abstract
As a result of a Department of Defense (DoD) mandate, the U.S. Navy implemented its current body composition assessment (BCA) program in 1982. Despite the feasibility of the current program, its re...
- Published
- 2019
4. Periodic Fitness Testing: Not Just for Athletes Anymore
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David D. Peterson
- Subjects
021110 strategic, defence & security studies ,medicine.medical_specialty ,biology ,Athletes ,0211 other engineering and technologies ,Fitness Testing ,030229 sport sciences ,02 engineering and technology ,Physical strength ,biology.organism_classification ,03 medical and health sciences ,0302 clinical medicine ,Physical therapy ,medicine ,Anaerobic capacity ,Psychology ,Aerobic capacity - Published
- 2018
5. Comparing Alternate Aerobic Tests for United States Navy Physical Readiness Test
- Author
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Melissa A. Rittenhouse, Austin W. Latour, David D. Peterson, and Daniel D. Riner
- Subjects
Engineering ,medicine.medical_specialty ,Age differences ,business.industry ,Physical fitness ,Test (assessment) ,Navy ,Stationary bike ,Physical therapy ,medicine ,Cycle ergometer ,book.short_story ,Aerobic exercise ,business ,book ,Simulation ,Active duty military - Abstract
The current Navy Physical Readiness Test allows for several alternatives to test aerobic fitness. Two currently approved alternate aerobic devices (elliptical trainer and stationary bike) were tested for correlation to VO2max and measured 1.5-mile run times. Two additional devices (2-km rower and 5-km cycle ergometer) were also evaluated as possible alternates. 132 active duty military and Naval Academy midshipmen were recruited from the United States Naval Academy. Subjects participated in six testing sessions over an eight-week period. Subjects performed a VO2max test (n = 96), 1.5 mile run (n = 118), 12-minute stationary bike test (n = 115), 12-minute elliptical trainer test (n = 108), 5-km cycle ergometer test (n = 114), and 2-km rower test (n = 115). Performances in all tests were correlated with one another. The strongest correlation to VO2max existed with the 1.5-mile run (r = –0.84). The 5-km cycle ergometer test (r = –0.42), 2-km rower test (r = –0.42), 12-minute stationary bike test (r =...
- Published
- 2017
6. A Practical Guide to Personal Conditioning
- Author
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David D Peterson, Melissa Rittenhouse, David D Peterson, and Melissa Rittenhouse
- Subjects
- Nutrition, Exercise--Physiological aspects, Physical fitness--Physiological aspects, Physical fitness
- Abstract
A Practical Guide to Personal Conditioning presents a safe and scientific approach to exercise prescription, programming, and nutrition. Appropriate for an array of fitness and personal training courses, it provides readers with the information and resources necessary to develop an exercise and nutrition plan specifically designed and tailored to fit their personal fitness goals.
- Published
- 2019
7. The Navy Physical Fitness Test
- Author
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David D. Peterson
- Subjects
Navy ,Aeronautics ,business.industry ,Physical fitness ,business ,Psychology ,Test (assessment) - Published
- 2015
8. Comparing Performance Category Criteria for U.S. Navy Alternate Physical Readiness Tests
- Author
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Melissa A. Rittenhouse, Austin W. Latour, David D. Peterson, and Daniel D. Riner
- Subjects
Matching (statistics) ,Navy ,Serif ,Span (category theory) ,Trainer ,Stationary bike ,Applied psychology ,Aerobic exercise ,book.short_story ,Psychology ,book ,Test (assessment) - Abstract
1. Abstract The current Navy Physical Readiness Test (PRT) allows for several alternative methods, in lieu of the 1.5-mile run, with which to assess aerobic fitness. Two of these methods (elliptical trainer and stationary bike) and two additional devices (2-Km rower and 5-Km bike) were evaluated to determine if maximal effort on all devices produced the same performance category as the 1.5-mile run. One hundred thirty-two active-duty military and midshipmen were recruited from the United States Naval Academy and Naval Support Activity Annapolis. Subjects participated in six testing sessions over a six-week period. Subjects performed a 1.5-mile run (n = 118), 12-minute elliptical trainer test (n = 108), 12-minute stationary bike test (n = 115), 2-Km rower test (n = 115), and 5-Km bike test (n = 114). Each performance category attained from the alternate aerobic test device was compared to the performance category attained for the 1.5-mile run. None of the aerobic testing devices performance categories matched well to the 1.5-mile run. The results of the testing sessions support the mandated use of the 1.5-mile run as the sole method of assessing aerobic fitness. Additionally, if an alternate method must be used, the 12-minute stationary bike test using the revised Naval Health Research Center (NHRC) performance categories might be the best option because it has the largest number of performance matching categories. Finally, the results do not support the use of the 12-minute elliptical test, as an authorized alternative, due to its minimal number of matching categories. 2. Keywords : Navy; Physical; Readiness
- Published
- 2017
9. Proposed Performance Standards for the Plank for Inclusion Consideration Into the Navy's Physical Readiness Test
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David D. Peterson
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Navy ,Aeronautics ,business.industry ,Medicine ,business ,Inclusion (education) ,Plank ,Test (assessment) - Published
- 2013
10. Possible New Modalities for the Navy Physical Readiness Test
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Lawrence W. Weiss, Paul N. Whitehead, Brian K. Schilling, and David D. Peterson
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Adult ,Male ,medicine.medical_specialty ,Modalities ,business.industry ,Public Health, Environmental and Occupational Health ,Squat ,General Medicine ,Standing long jump ,United States ,Test (assessment) ,Military medicine ,Navy ,Military Personnel ,Physical Fitness ,Exercise Test ,Physical Endurance ,Physical therapy ,Humans ,Medicine ,Aerobic exercise ,Female ,Naval Medicine ,business ,Cadence - Abstract
The current U.S. Navy Physical Readiness Test (PRT) measures aerobic fitness and muscular endurance via a 1 1/2 mile run and curl-up/push-up tests, respectively. Nine new modalities were recommended to either replace or supplement the current PRT. Personnel and civilians (N = 179) were recruited from a local Navy base and participated in all modalities (duplicate if possible) over 4 weeks following familiarization sessions. Subjects performed single-leg plank, single-leg wall squat, cadence push-ups, leg/hip dynamometer, standing long jump, and pro-agility test. Cardiovascular modalities were also performed via the 300-yard shuttle, 2-km row, and 5-km bike. Performance in the modalities was correlated to the subjects' existing PRT scores as well as within the new modalities. Although most modalities could not be concretely recommended, the plank and wall squat were eliminated from consideration because of poor reliability scores. The strongest correlation existed between the standing long jump and pro-agility test for the entire sample. Correlation scores were also analyzed by gender. The cardiovascular modalities did not have strong enough scores to elicit a recommendation to replace the 1 1/2 mile run, but future considerations for similar testing would be to collect scores for the existing modalities in addition to the proposed modalities.
- Published
- 2012
11. History of the U.S. Navy Body Composition program
- Author
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David D. Peterson
- Subjects
Male ,Less invasive ,U s navy ,Composition analysis ,Body fat percentage ,History, 21st Century ,Aeronautics ,Medicine ,Humans ,Military Medicine ,Naval Medicine ,Circumference measurements ,business.industry ,Abdominal circumference ,Public Health, Environmental and Occupational Health ,General Medicine ,History, 20th Century ,Military personnel ,Navy ,Military Personnel ,Physical Fitness ,Aerospace Medicine ,Body Composition ,Female ,Waist Circumference ,business - Abstract
The Navy currently employs maximum weight-for-height tables and body fat prediction equations based on circumference measurements to assess body composition. However, many Sailors believe the current method fails to accurately predict body fat percentage. As a result, the Naval Health Research Center (NHRC) conducted numerous studies in an attempt to improve the accuracy and reliability of the Navy's Body Composition Analysis program. In 2012, NHRC conducted a study that researched the feasibility of using a single abdominal circumference (AC) measurement in lieu of circumference measurements. The Air Force and National Institutes of Health (NIH) employ a single AC measurement taken at the superior border of the iliac crest to assess body composition and all-cause mortality risk. Although the Air Force and NIH use the iliac crest, NHRC is proposing the Navy use the umbilicus as the AC site since it is less invasive and easier to identify. If implemented, the Navy would use cutoff values of 40 in. and 36 in. for males and females, respectively. The purpose of this article is to provide a brief history of the Navy's Body Composition Analysis program as well as propose the transition from circumference measurements to a single AC measurement.
- Published
- 2015
12. Vegetation of South Masailand, Tanzania a Range Habitat Classification
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David D. Peterson and Burd S. McGinnes
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Geography ,Tanzania ,biology ,Habitat ,Range (biology) ,medicine ,Physical geography ,medicine.symptom ,biology.organism_classification ,Vegetation (pathology) - Published
- 1979
13. Factors in a programmed approach to therapy
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David D. Peterson and Dolores S. Butt
- Subjects
Programmed Instructions as Topic ,Otorhinolaryngology ,Tape Recording ,Humans ,Psychology ,Reinforcement, Psychology ,Speech Disorders ,Feedback - Published
- 1972
14. Simulation at Mach 2 flow of ethylene/air reacting mixture within a cavity flame holder.
- Author
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Chapman Z, Peterson D, and Doom J
- Abstract
The ongoing simulation of flame holder cavities remains a pivotal aspect in the advancement of scramjet engine development. This study aims to evaluate the applicability of Reynolds Averaged Navier-Stokes (RANS) turbulence models in simulating supersonic reacting flows within flame holder cavities. RANS remains the standard approach for engineering simulations in this regime, so it is important to understand how different RANS models perform. Four RANS turbulence models, the k- ϵ , Realizable k- ϵ , k- ω SST, and v 2 ‾ - f models, are used for the simulation of a flame holder cavity at Mach 2 using two different chemical mechanisms. Results were compared to experimental data and prior simulation results from the Air Force Research Laboratory (AFRL). The v 2 ‾ - f turbulence model was found to provide the best overall results and often provided similar or superior results to previous results using a higher fidelity hybrid RANS/LES approach. Additionally, the two chemical mechanisms are compared, with the smaller of the two mechanisms being found to provide better results when used with the RANS models investigated in this work., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2024 The Author(s).)
- Published
- 2024
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15. Severe congenital neutropenia, SRP54 pathogenicity, and a framework for surveillance.
- Author
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Fan EM, Vagher J, Meznarich JA, Ubico EM, Goteti S, Peterson D, Rayes A, and Maese LD
- Subjects
- Infant, Humans, Virulence, Mutation, Congenital Bone Marrow Failure Syndromes genetics, Shwachman-Diamond Syndrome, Signal Recognition Particle genetics, Adaptor Proteins, Signal Transducing genetics, Neutropenia genetics, Neutropenia pathology
- Abstract
Severe congenital neutropenia (SCN) is a rare disorder, often due to pathogenic variants in genes such as ELANE, HAX1, and SBDS. SRP54 pathogenic variants are associated with SCN and Shwachman-Diamond-like syndrome. Thirty-eight patients with SRP54-related SCN are reported in the literature. We present an infant with SCN, without classic Shwachman-Diamond syndrome features, who presented with recurrent bacterial infections and an SRP54 (c.349_351del) pathogenic variant. Despite ongoing granulocyte colony-stimulating factor therapy, this patient has no evidence of malignant transformation. Here we establish a framework for the future development of universal guidelines to care for this patient population., (© 2023 Wiley Periodicals LLC.)
- Published
- 2023
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16. E-learning/online education in transfusion medicine: A cross-sectional international survey.
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Al-Riyami AZ, Peterson D, Vanden Broeck J, Das S, Saxon B, Lin Y, Rahimi-Levene N, So-Osman C, and Stanworth S
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- Humans, Cross-Sectional Studies, Pandemics, COVID-19, Education, Distance methods, Transfusion Medicine, Computer-Assisted Instruction
- Abstract
Objectives: This survey aims to assess the scope of transfusion e-learning courses in blood establishments and transfusion services internationally., Background: E-learning/online education is increasingly used in the education of medical professionals. There is limited published data on the use of e-learning for transfusion medicine., Material and Methods: An International survey was designed and distributed to all members of the International Society of Blood Transfusion to assess utilisation of e-learning in their institutions. Descriptive statistics were used to summarise the results., Results: A total of 177 respondents participated, 68 of which had e-learning modules in their institutions. Approximately two-thirds of the courses were developed in-house (66%), and 63% are available to learners from outside the host institutions. In one-third of institutions, these courses were established during the COVID-19 pandemic, while 15% had used e-learning courses for more than 10 years. The courses target different audiences and topics ranging from blood donation to hemovigilance. The most common audiences were physicians (71%), laboratory scientists/technologists (69%) and transfusion practitioners (63%). Formal assessment of learning outcomes is used in 70% of the programs., Conclusions: The survey demonstrates the widespread use of e-learning courses in transfusion education, with a substantial proportion being developed during the COVID-19 pandemic., (© 2022 British Blood Transfusion Society.)
- Published
- 2022
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17. Structure-based optimization of hydroxylactam as potent, cell-active inhibitors of lactate dehydrogenase.
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Wei B, Robarge K, Labadie SS, Chen J, Corson LB, DiPasquale A, Dragovich PS, Eigenbrot C, Evangelista M, Fauber BP, Hitz A, Hong R, Lai KW, Liu W, Ma S, Malek S, O'Brien T, Pang J, Peterson D, Salphati L, Sampath D, Sideris S, Ultsch M, Xu Z, Yen I, Yu D, Yue Q, Zhou A, and Purkey HE
- Subjects
- Animals, Cell Line, Dogs, Dose-Response Relationship, Drug, Enzyme Inhibitors chemistry, Humans, L-Lactate Dehydrogenase metabolism, Lactams chemistry, Mice, Microsomes, Liver chemistry, Microsomes, Liver metabolism, Molecular Structure, Structure-Activity Relationship, Enzyme Inhibitors pharmacology, L-Lactate Dehydrogenase antagonists & inhibitors, Lactams pharmacology
- Abstract
Structure-based design was utilized to optimize 6,6-diaryl substituted dihydropyrone and hydroxylactam to obtain inhibitors of lactate dehydrogenase (LDH) with low nanomolar biochemical and single-digit micromolar cellular potencies. Surprisingly the replacement of a phenyl with a pyridyl moiety in the chemical structure revealed a new binding mode for the inhibitors with subtle conformational change of the LDHA active site. This led to the identification of a potent, cell-active hydroxylactam inhibitor exhibiting an in vivo pharmacokinetic profile suitable for mouse tumor xenograft study., (Copyright © 2022 Elsevier Ltd. All rights reserved.)
- Published
- 2022
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18. Spinodal de-wetting of light liquids on graphene.
- Author
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Vanegas JM, Peterson D, Lakoba TI, and Kotov VN
- Abstract
We demonstrate theoretically the possibility of spinodal de-wetting in heterostructures made of light-atom liquids (hydrogen, helium, and nitrogen) deposited on suspended graphene. Extending our theory of film growth on two-dimensional (2D) materials to include analysis of surface instabilities via the hydrodynamic Cahn-Hilliard-type equation, we characterize in detail the spatial and temporal scales of the resulting spinodal de-wetting patterns. Both linear stability analysis and direct numerical simulations of the surface hydrodynamics show micron-sized (generally material dependent) patterns of 'dry' regions. The physical reason for the development of such instabilities on graphene can be traced back to the inherently weak van der Waals interactions between atomically thin materials and atoms in the liquid. Thus 2D materials could represent a new theoretical and technological platform for studies of spinodal de-wetting., (© 2022 IOP Publishing Ltd.)
- Published
- 2022
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19. Self-correction in science: The diagnostic and integrative motives for replication.
- Author
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Peterson D and Panofsky A
- Subjects
- Policy, Product Labeling
- Abstract
A series of failed replications and frauds have raised questions regarding self-correction in science. Metascientific activists have advocated policies that incentivize replications and make them more diagnostically potent. We argue that current debates, as well as research in science and technology studies, have paid little heed to a key dimension of replication practice. Although it sometimes serves a diagnostic function, replication is commonly motivated by a practical desire to extend research interests. The resulting replication, which we label 'integrative', is characterized by a pragmatic flexibility toward protocols. The goal is to appropriate what is useful, not test for truth. Within many experimental cultures, however, integrative replications can produce replications of ambiguous diagnostic power. Based on interviews with 60 members of the Board of Reviewing Editors for the journal Science , we show how the interplay between the diagnostic and integrative motives for replication differs between fields and produces different cultures of replication. We offer six theses that aim to put science and technology studies and science activism into dialog to show why effective reforms will need to confront issues of disciplinary difference.
- Published
- 2021
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20. The replication crisis won't be solved with broad brushstrokes.
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Peterson D
- Published
- 2021
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21. Quantitative Lesser Trochanter Profile Versus Cortical Step Sign in Assessing Femoral Malrotation After Femoral Nailing.
- Author
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Klaucke J, O'Hara NN, Peterson D, Gitajn IL, Natoli R, Sciadini MF, Manson TT, Nascone JW, Gage M, LeBrun C, Pollak AN, and O'Toole RV
- Subjects
- Femur diagnostic imaging, Femur surgery, Humans, Osteotomy, Femoral Fractures diagnostic imaging, Femoral Fractures surgery, Fracture Fixation, Intramedullary
- Abstract
We describe the novel quantitative lesser trochanter profile (QLTP) technique to determine the magnitude and direction of femoral malrotation and to compare its performance with the cortical step sign technique. For this assessment, 9 orthopaedic surgeons estimated the magnitude and direction of femoral malrotation with each technique in 198 anteroposterior view images of the proximal cadaveric femur and osteotomy sites. Based on the results, the main benefit of the QLTP technique over the cortical step sign technique is the ability to determine the direction of femoral malrotation. The QLTP technique was also more accurate in measuring malrotation and had less error. However, the QLTP technique requires additional imaging, and the mean difference in error between the 2 techniques might not be clinically meaningful.
- Published
- 2020
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22. Delayed periprosthetic collection after cervical disc arthroplasty.
- Author
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Harris L, Dyson E, Elliot M, Peterson D, Ulbricht C, and Casey A
- Abstract
Cervical disc arthroplasty is a treatment option for symptomatic cervical disc disease. There is a paucity of literature on long-term safety outcomes, durability, and device-related failure rates. The M6-C artificial cervical disc is a device with titanium alloy endplates and a complex polymeric centerpiece. To date, trials have exhibited acceptable safety profiles.This case series describes the presentation, management, and pathological findings of a delayed prevertebral periprosthetic mass anterior to the M6-C disc. Four patients at 3 different institutions underwent cervical disc replacement with the M6-C disc. Two to seven years postoperatively, they presented with dysphagia secondary to a compressive mass anterior to the disc. Case notes were reviewed to collect data on symptoms, management, and outcomes. The patients were systemically well and presented with progressive dysphagia. They had imaging findings of a mass anterior to the disc. They underwent a decompressive procedure, with 2 patients undergoing device removal and fusion. In 2 cases, a soft-tissue mass was seen intraoperatively, with frank pus. In 3 cases, Propionibacterium acnes was identified and antibiotic treatment given. Histopathology demonstrated mixed inflammatory infiltrates with foreign body-type granulomas. Postoperatively, the dysphagia resolved.The development of delayed dysphagia in a patient with an M6-C disc should prompt investigation to identify a mass lesion. To the authors' knowledge, this is the first report of delayed infection, or suspected delayed-type hypersensitivity reaction, following M6-C disc implantation. It is important for this to be added to the device safety concerns. Further prospective studies are needed to establish the incidence and the long-term safety and failure rates of the M6-C disc.
- Published
- 2019
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23. Imaging and Tissue Biomarkers of Choline Metabolism in Diffuse Adult Glioma: 18F-Fluoromethylcholine PET/CT, Magnetic Resonance Spectroscopy, and Choline Kinase α.
- Author
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Grech-Sollars M, Ordidge KL, Vaqas B, Davies C, Vaja V, Honeyfield L, Camp S, Towey D, Mayers H, Peterson D, O'Neill K, Roncaroli F, Barwick TD, and Waldman AD
- Abstract
The cellular and molecular basis of choline uptake on PET imaging and MRS-visible choline-containing compounds is not well understood. Choline kinase alpha (ChoKα) is an enzyme that phosphorylates choline, an essential step in membrane synthesis. We investigate choline metabolism through 18F-fluoromethylcholine (18F-FMC) PET, MRS, and tissue ChoKα in human glioma. Fourteen patients with a suspected diffuse glioma underwent multimodal 3T MRI and dynamic 18F-FMC PET/CT prior to surgery. Co-registered PET and MRI data were used to target biopsies to regions of high and low choline signal, and immunohistochemistry for ChoKα expression was performed. The 18F-FMC/PET differentiated WHO (World Health Organization) grade IV from grade II and III tumours, whereas MRS differentiated grade III/IV from grade II tumours. Tumoural 18F-FMC/PET uptake was higher than in normal-appearing white matter across all grades and markedly elevated within regions of contrast enhancement. The 18F-FMC/PET correlated weakly with MRS Cho ratios. ChoKα expression on IHC was negative or weak in all but one glioblastoma sample, and did not correlate with tumour grade or imaging choline markers. MRS and 18F-FMC/PET provide complimentary information on glioma choline metabolism. Tracer uptake is, however, potentially confounded by blood-brain barrier permeability. ChoKα overexpression does not appear to be a common feature in diffuse glioma.
- Published
- 2019
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24. Pan-Cancer Metabolic Signature Predicts Co-Dependency on Glutaminase and De Novo Glutathione Synthesis Linked to a High-Mesenchymal Cell State.
- Author
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Daemen A, Liu B, Song K, Kwong M, Gao M, Hong R, Nannini M, Peterson D, Liederer BM, de la Cruz C, Sangaraju D, Jaochico A, Zhao X, Sandoval W, Hunsaker T, Firestein R, Latham S, Sampath D, Evangelista M, and Hatzivassiliou G
- Subjects
- Animals, Biomarkers, Tumor metabolism, Cell Line, Tumor, Citric Acid metabolism, Databases, Genetic, Female, Glutathione metabolism, HEK293 Cells, Humans, Isoenzymes metabolism, Mice, Mice, Inbred BALB C, Mice, Nude, Mice, SCID, Tumor Stem Cell Assay, Xenograft Model Antitumor Assays, Breast Neoplasms drug therapy, Breast Neoplasms metabolism, Glutamate-Cysteine Ligase antagonists & inhibitors, Glutamate-Cysteine Ligase metabolism, Glutaminase antagonists & inhibitors, Glutaminase metabolism, Lung Neoplasms drug therapy, Lung Neoplasms metabolism, Mesenchymal Stem Cells drug effects, Mesenchymal Stem Cells pathology, Metabolome
- Abstract
The enzyme glutaminase (GLS1) is currently in clinical trials for oncology, yet there are no clear diagnostic criteria to identify responders. The evaluation of 25 basal breast lines expressing GLS1, predominantly through its splice isoform GAC, demonstrated that only GLS1-dependent basal B lines required it for maintaining de novo glutathione synthesis in addition to mitochondrial bioenergetics. Drug sensitivity profiling of 407 tumor lines with GLS1 and gamma-glutamylcysteine synthetase (GCS) inhibitors revealed a high degree of co-dependency on both enzymes across indications, suggesting that redox balance is a key function of GLS1 in tumors. To leverage these findings, we derived a pan-cancer metabolic signature predictive of GLS1/GCS co-dependency and validated it in vivo using four lung patient-derived xenograft models, revealing the additional requirement for expression of GAC above a threshold (log
2 RPKM + 1 ≥ 4.5, where RPKM is reads per kilobase per million mapped reads). Analysis of the pan-TCGA dataset with our signature identified multiple indications, including mesenchymal tumors, as putative responders to GLS1 inhibitors., (Copyright © 2018 Elsevier Inc. All rights reserved.)- Published
- 2018
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25. Expanding Our Work: A Multifaceted Approach to Improving Mental Health Access.
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Lehrmann J, Peterson D, Kerschner JE, and Raymond JR Sr
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- Humans, Medically Underserved Area, Models, Organizational, Quality Improvement, Schools, Medical, Wisconsin, Health Services Accessibility organization & administration, Mental Health Services organization & administration
- Published
- 2018
26. Objective image analysis of real-time three-dimensional intraoperative ultrasound for intrinsic brain tumour surgery.
- Author
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Camp SJ, Apostolopoulos V, Raptopoulos V, Mehta A, O'Neill K, Awad M, Vaqas B, Peterson D, Roncaroli F, and Nandi D
- Abstract
Background: There is growing evidence that maximal surgical resection of primary intrinsic brain tumours is beneficial, both by improving progression free and overall survival and also by facilitating postoperative chemotherapy and radiotherapy. Hence, there has been an increase in the popularity of real-time intraoperative imaging in brain tumour surgery. The complex theatre arrangements, prohibitive cost and prolonged theatre time of intraoperative MRI have restricted its application. By comparison, intraoperative three-dimensional ultrasound (i3DUS) is user friendly, cost-effective and portable and adds little to surgical time. However, operator-dependent image quality and image interpretation remain limiting factors to the wider application of this technique. The aim of this study was to explore objective i3DUS image analysis and its potential therapeutic role in brain tumour surgery., Methods: A prospective, observational study was undertaken (approved by the local Research and Ethics Committee prior to recruitment). Biopsies were taken from the solid, necrotic, periphery and brain/tumour interface of intrinsic primary brain tumours. Digital i3DUS images were analysed to extract quantitative parameters from these regions of interest (ROI) in the i3DUS images. These were then correlated with the histology of the relevant specimens. The histopathologist was blinded to the imaging findings., Results: Ninety-seven patients (62 males; mean 54 years) with varying gliomas (84 high grade) were included. Two hundred and ninety regions of interest were analysed. Mean pixel brightness (MPB) and standard deviation (SD) were correlated with histological features. Close correlations were noted between MPB and cellularity, and SD and intrinsic cellular diversity., Conclusions: MPB and SD are objective measures reflecting the sensitivity of i3DUS in detecting the presence and extent of intrinsic brain tumours. They indirectly suggest heterogeneity, cellularity and invasiveness, providing information of the nature of the tumour, and also reflect the sensitivity of intraoperative US to detect the presence of residual intrinsic brain tumours. Development of this paradigm will enhance i3DUS use as an adjunct in brain tumour surgery. Optimizing its intraoperative application will impact surgical resection and, hence, patient outcome.
- Published
- 2017
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27. The depth of fields: Managing focus in the epistemic subcultures of mind and brain science.
- Author
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Peterson D
- Subjects
- History, 20th Century, Knowledge, Neurosciences history, Philosophy history, Biological Science Disciplines history, Psychology history, Science history
- Abstract
The 'psy' sciences emerged from the tangled roots of philosophy, physiology, biology and medicine, and these origins have produced heterogeneous fields. Scientists in these areas work in a complex, overlapping ecology of fields that results in the constant co-presence of dissonant theories, methods and research objects. This raises questions regarding how conceptual clarity is maintained. Using the optical metaphor 'depth of field', I show how researchers in all fields marginalize potential threats to routine scientific work by framing them as either too broad and imprecise or too narrow and technical. The appearance of this defocusing and devaluing across sites suggests a general aspect of scientific cognition, rather than a by-product of any specific scientific dispute.
- Published
- 2017
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28. All The Catalytic Active Sites of MoS 2 for Hydrogen Evolution.
- Author
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Li G, Zhang D, Qiao Q, Yu Y, Peterson D, Zafar A, Kumar R, Curtarolo S, Hunte F, Shannon S, Zhu Y, Yang W, and Cao L
- Abstract
MoS
2 presents a promising low-cost catalyst for the hydrogen evolution reaction (HER), but the understanding about its active sites has remained limited. Here we present an unambiguous study of the catalytic activities of all possible reaction sites of MoS2 , including edge sites, sulfur vacancies, and grain boundaries. We demonstrate that, in addition to the well-known catalytically active edge sites, sulfur vacancies provide another major active site for the HER, while the catalytic activity of grain boundaries is much weaker. The intrinsic turnover frequencies (Tafel slopes) of the edge sites, sulfur vacancies, and grain boundaries are estimated to be 7.5 s-1 (65-75 mV/dec), 3.2 s-1 (65-85 mV/dec), and 0.1 s-1 (120-160 mV/dec), respectively. We also demonstrate that the catalytic activity of sulfur vacancies strongly depends on the density of the vacancies and the local crystalline structure in proximity to the vacancies. Unlike edge sites, whose catalytic activity linearly depends on the length, sulfur vacancies show optimal catalytic activities when the vacancy density is in the range of 7-10%, and the number of sulfur vacancies in high crystalline quality MoS2 is higher than that in low crystalline quality MoS2 , which may be related with the proximity of different local crystalline structures to the vacancies.- Published
- 2016
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29. Diffusion tensor imaging analysis of the brain in the canine model of Krabbe disease.
- Author
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Bradbury A, Peterson D, Vite C, Chen S, Ellinwood NM, and Provenzale J
- Subjects
- Animals, Anisotropy, Disease Models, Animal, Dogs, Image Processing, Computer-Assisted, Leukodystrophy, Globoid Cell diagnostic imaging, Leukodystrophy, Globoid Cell veterinary, Mice, White Matter diagnostic imaging, White Matter pathology, Brain diagnostic imaging, Diffusion Magnetic Resonance Imaging, Leukodystrophy, Globoid Cell pathology
- Abstract
Purpose: The goal of this study was to compare the diffusion tensor imaging (DTI) metrics from an end-stage canine Krabbe brain evaluated by MR imaging ex vivo to those of a normal dog brain. We hypothesized that the white matter of the canine Krabbe brain would show decreased fractional anisotropy (FA) values and increased apparent diffusion coefficient (ADC) and radial diffusivity (RD) values., Methods: An 11-week-old Krabbe dog was euthanized after disease progression. The brain was removed and was placed in a solution of 10% formalin. MR imaging was performed and compared to the brain images of a normal dog that was similarly fixed post-mortem. Both brains were scanned using similar protocols on a 7 T small-animal MRI system. For each brain, maps of ADC, FA, and RD were calculated for 11 white-matter regions and five control gray-matter regions., Results: Large decreases in FA values, increases in ADC values, and increases in RD (consistent with demyelination) values, were seen in white matter of the Krabbe brain but not gray matter. ADC values in gray matter of the Krabbe brain were decreased by approximately 29% but increased by approximately 3.6% in white matter of the Krabbe brain. FA values in gray matter were decreased by approximately 3.3% but decreased by approximately 29% in white matter. RD values were decreased by approximately 27.2% in gray matter but increased by approximately 20% in white matter., Conclusion: We found substantial abnormalities of FA, ADC, and RD values in an ex vivo canine Krabbe brain., (© The Author(s) 2016.)
- Published
- 2016
- Full Text
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30. Metabolic plasticity underpins innate and acquired resistance to LDHA inhibition.
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Boudreau A, Purkey HE, Hitz A, Robarge K, Peterson D, Labadie S, Kwong M, Hong R, Gao M, Del Nagro C, Pusapati R, Ma S, Salphati L, Pang J, Zhou A, Lai T, Li Y, Chen Z, Wei B, Yen I, Sideris S, McCleland M, Firestein R, Corson L, Vanderbilt A, Williams S, Daemen A, Belvin M, Eigenbrot C, Jackson PK, Malek S, Hatzivassiliou G, Sampath D, Evangelista M, and O'Brien T
- Subjects
- Cell Death drug effects, Cell Line, Tumor, Cell Proliferation drug effects, Dose-Response Relationship, Drug, Enzyme Inhibitors chemistry, Humans, L-Lactate Dehydrogenase metabolism, Models, Molecular, Molecular Structure, Pyridones chemistry, Structure-Activity Relationship, Thiophenes chemistry, Cell Plasticity drug effects, Enzyme Inhibitors pharmacology, L-Lactate Dehydrogenase antagonists & inhibitors, Pyridones pharmacology, Thiophenes pharmacology
- Abstract
Metabolic reprogramming in tumors represents a potential therapeutic target. Herein we used shRNA depletion and a novel lactate dehydrogenase (LDHA) inhibitor, GNE-140, to probe the role of LDHA in tumor growth in vitro and in vivo. In MIA PaCa-2 human pancreatic cells, LDHA inhibition rapidly affected global metabolism, although cell death only occurred after 2 d of continuous LDHA inhibition. Pancreatic cell lines that utilize oxidative phosphorylation (OXPHOS) rather than glycolysis were inherently resistant to GNE-140, but could be resensitized to GNE-140 with the OXPHOS inhibitor phenformin. Acquired resistance to GNE-140 was driven by activation of the AMPK-mTOR-S6K signaling pathway, which led to increased OXPHOS, and inhibitors targeting this pathway could prevent resistance. Thus, combining an LDHA inhibitor with compounds targeting the mitochondrial or AMPK-S6K signaling axis may not only broaden the clinical utility of LDHA inhibitors beyond glycolytically dependent tumors but also reduce the emergence of resistance to LDHA inhibition.
- Published
- 2016
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31. Cell Active Hydroxylactam Inhibitors of Human Lactate Dehydrogenase with Oral Bioavailability in Mice.
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Purkey HE, Robarge K, Chen J, Chen Z, Corson LB, Ding CZ, DiPasquale AG, Dragovich PS, Eigenbrot C, Evangelista M, Fauber BP, Gao Z, Ge H, Hitz A, Ho Q, Labadie SS, Lai KW, Liu W, Liu Y, Li C, Ma S, Malek S, O'Brien T, Pang J, Peterson D, Salphati L, Sideris S, Ultsch M, Wei B, Yen I, Yue Q, Zhang H, and Zhou A
- Abstract
A series of trisubstituted hydroxylactams was identified as potent enzymatic and cellular inhibitors of human lactate dehydrogenase A. Utilizing structure-based design and physical property optimization, multiple inhibitors were discovered with <10 μM lactate IC
50 in a MiaPaca2 cell line. Optimization of the series led to 29 , a potent cell active molecule (MiaPaca2 IC50 = 0.67 μM) that also possessed good exposure when dosed orally to mice.- Published
- 2016
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32. A Direct Comparison of Three Clinically Relevant Treatments in a Rat Model of Cervical Spinal Cord Injury.
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Hosier H, Peterson D, Tsymbalyuk O, Keledjian K, Smith BR, Ivanova S, Gerzanich V, Popovich PG, and Simard JM
- Subjects
- Animals, Behavior, Animal, Disease Models, Animal, Female, Glyburide administration & dosage, Glyburide adverse effects, Hypoglycemic Agents administration & dosage, Hypoglycemic Agents adverse effects, Motor Activity, Neuroprotective Agents administration & dosage, Neuroprotective Agents adverse effects, Rats, Rats, Long-Evans, Riluzole administration & dosage, Riluzole adverse effects, Spinal Cord Injuries drug therapy, Cervical Cord injuries, Glyburide pharmacology, Hypoglycemic Agents pharmacology, Hypothermia, Induced methods, Neuroprotective Agents pharmacology, Riluzole pharmacology, Spinal Cord Injuries therapy
- Abstract
Recent preclinical studies have identified three treatments that are especially promising for reducing acute lesion expansion following traumatic spinal cord injury (SCI): riluzole, systemic hypothermia, and glibenclamide. Each has demonstrated efficacy in multiple studies with independent replication, but there is no way to compare them in terms of efficacy or safety, since different models were used, different laboratories were involved, and different outcomes were evaluated. Here, using a model of lower cervical hemicord contusion, we compared safety and efficacy for the three treatments, administered beginning 4 h after trauma. Treatment-associated mortality was 30% (3/10), 30% (3/10), 12.5% (1/8), and 0% (0/7) in the control, riluzole, hypothermia, and glibenclamide groups, respectively. For survivors, all three treatments showed overall favorable efficacy, compared with controls. On open-field locomotor scores (modified Basso, Beattie, and Bresnahan scores), hypothermia- and glibenclamide-treated animals were largely indistinguishable throughout the study, whereas riluzole-treated rats underperformed for the first two weeks; during the last four weeks, scores for the three treatments were similar, and significantly different from controls. On beam balance, hypothermia and glibenclamide treatments showed significant advantages over riluzole. After trauma, rats in the glibenclamide group rapidly regained a normal pattern of weight gain that differed markedly and significantly from that in all other groups. Lesion volumes at six weeks were: 4.8±0.7, 3.5±0.4, 3.1±0.3 and 2.5±0.3 mm(3) in the control, riluzole, hypothermia, and glibenclamide groups, respectively; measurements of spared spinal cord tissue confirmed these results. Overall, in terms of safety and efficacy, systemic hypothermia and glibenclamide were superior to riluzole.
- Published
- 2015
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33. Metabolite profiling stratifies pancreatic ductal adenocarcinomas into subtypes with distinct sensitivities to metabolic inhibitors.
- Author
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Daemen A, Peterson D, Sahu N, McCord R, Du X, Liu B, Kowanetz K, Hong R, Moffat J, Gao M, Boudreau A, Mroue R, Corson L, O'Brien T, Qing J, Sampath D, Merchant M, Yauch R, Manning G, Settleman J, Hatzivassiliou G, and Evangelista M
- Subjects
- Adenocarcinoma genetics, Adenocarcinoma pathology, Biomarkers, Tumor metabolism, Carcinoma, Pancreatic Ductal genetics, Carcinoma, Pancreatic Ductal pathology, Cell Proliferation, Glucose metabolism, Glutamine metabolism, Glycolysis genetics, Humans, Inhibitory Concentration 50, Lipogenesis genetics, Mesoderm metabolism, Mesoderm pathology, Reproducibility of Results, Transcription, Genetic, Adenocarcinoma classification, Adenocarcinoma metabolism, Carcinoma, Pancreatic Ductal classification, Carcinoma, Pancreatic Ductal metabolism, Metabolome genetics, Metabolomics
- Abstract
Although targeting cancer metabolism is a promising therapeutic strategy, clinical success will depend on an accurate diagnostic identification of tumor subtypes with specific metabolic requirements. Through broad metabolite profiling, we successfully identified three highly distinct metabolic subtypes in pancreatic ductal adenocarcinoma (PDAC). One subtype was defined by reduced proliferative capacity, whereas the other two subtypes (glycolytic and lipogenic) showed distinct metabolite levels associated with glycolysis, lipogenesis, and redox pathways, confirmed at the transcriptional level. The glycolytic and lipogenic subtypes showed striking differences in glucose and glutamine utilization, as well as mitochondrial function, and corresponded to differences in cell sensitivity to inhibitors of glycolysis, glutamine metabolism, lipid synthesis, and redox balance. In PDAC clinical samples, the lipogenic subtype associated with the epithelial (classical) subtype, whereas the glycolytic subtype strongly associated with the mesenchymal (QM-PDA) subtype, suggesting functional relevance in disease progression. Pharmacogenomic screening of an additional ∼ 200 non-PDAC cell lines validated the association between mesenchymal status and metabolic drug response in other tumor indications. Our findings highlight the utility of broad metabolite profiling to predict sensitivity of tumors to a variety of metabolic inhibitors.
- Published
- 2015
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34. Hypertrophic pachymeningitis with sarcoidosis: a rare cause of craniocervical compression.
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Subrati N, Vaqas B, Peterson D, and Patel MC
- Subjects
- Decompression, Surgical methods, Female, Humans, Magnetic Resonance Imaging, Meningitis complications, Meningitis surgery, Middle Aged, Sarcoidosis complications, Spinal Cord Compression etiology, Spinal Cord Compression surgery, Tomography, X-Ray Computed, Treatment Outcome, Cervical Vertebrae pathology, Dura Mater pathology, Laminectomy methods, Meningitis diagnosis, Sarcoidosis diagnosis, Spinal Cord Compression diagnosis
- Abstract
We describe a case of a 58-year-old woman with a suspected dural tumour. She presented with progressive pyramidal weakness. MRI confirmed compression of the medulla oblongata and spinal cord at the level of C1-3. The localised dural mass lesion homogenously enhanced on T1 MRI and was considered most likely to be a meningioma. Incidentally, CT scan of the chest revealed peribronchial soft tissue thickening, suggestive of pulmonary sarcoidosis. Owing to the progressive nature of her weakness, she had a posterior occipitocervical decompression with a C1-3 laminectomy and resection of the thickened dura. Histology showed densely collagenous tissue with scanty psammoma bodies and multinucleate giant cells, consistent with hypertrophic pachymeningitis (HP)-a rare, chronic inflammatory condition, characterised by thickening and fibrosis of the dura. This case demonstrates that masses in the craniocervical junction can be varied in pathology and when there is evidence of systemic inflammation, HP should be considered., (2015 BMJ Publishing Group Ltd.)
- Published
- 2015
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35. Predictors of adverse cosmetic outcome in the RAPID trial: an exploratory analysis.
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Peterson D, Truong PT, Parpia S, Olivotto IA, Berrang T, Kim DH, Kong I, Germain I, Nichol A, Akra M, Roy I, Reed M, Fyles A, Trotter T, Perera F, Balkwill S, Lavertu S, Elliott E, Julian JA, Levine MN, and Whelan TJ
- Subjects
- Age Factors, Aged, Breast Diseases complications, Breast Neoplasms nursing, Breast Neoplasms pathology, Carcinoma, Ductal, Breast nursing, Carcinoma, Ductal, Breast pathology, Female, Humans, Infections complications, Logistic Models, Middle Aged, Radiation Injuries complications, Radiation Injuries nursing, Radiation Injuries pathology, Radiotherapy methods, Radiotherapy Dosage, Radiotherapy, Conformal methods, Risk Factors, Seroma complications, Seroma pathology, Time Factors, Treatment Outcome, Tumor Burden, Breast radiation effects, Breast Neoplasms radiotherapy, Carcinoma, Ductal, Breast radiotherapy, Esthetics, Radiotherapy, Conformal adverse effects
- Abstract
Purpose: To evaluate factors associated with adverse cosmesis outcome in breast cancer patients randomized to accelerated partial breast irradiation (APBI) using 3-dimensional conformal radiation therapy or whole-breast irradiation in the RAPID (Randomized Trial of Accelerated Partial Breast Irradiation) trial., Methods and Materials: Subjects were trial participants with nurse-assessed global cosmetic scores at baseline and at 3 years. Adverse cosmesis was defined as a score of fair or poor. Cosmetic deterioration was defined as any adverse change in score from baseline to 3 years. The analysis is based on data from the previously reported interim analysis. Logistic regression models were used to assess the association of risk factors for these outcomes among all patients and those treated with APBI only., Results: Clinicopathologic characteristics were similar between subjects randomized to APBI (n=569) or whole-breast irradiation (n=539). For all subjects, factors associated with adverse cosmesis at 3 years were older age, central/inner tumor location, breast infection, smoking, seroma volume, breast volume, and use of APBI; factors associated with cosmetic deterioration were smoking, seroma volume, and use of APBI (P<.05). For APBI subjects, tumor location, smoking, age, and seroma volume were associated with adverse cosmesis (P<.05), and smoking was associated with cosmetic deterioration (P=.02). An independent association between the V95/whole-breast volume ratio and adverse cosmesis (P=.28) or cosmetic deterioration (P=.07) was not detected. On further exploration a V95/whole-breast volume ratio <0.15 was associated with a lower risk of cosmetic deterioration (p=.04), but this accounted for only 11% of patients., Conclusion: In the RAPID trial, a number of patient tumor and treatment-related factors, including the use of APBI, were associated with adverse cosmesis and cosmetic deterioration. For patients treated with APBI alone, the high-dose treatment volume was not independently associated with an adverse cosmetic outcome, and a useful clinical threshold could not be identified., (Copyright © 2015 Elsevier Inc. All rights reserved.)
- Published
- 2015
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36. Optimization of 5-(2,6-dichlorophenyl)-3-hydroxy-2-mercaptocyclohex-2-enones as potent inhibitors of human lactate dehydrogenase.
- Author
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Labadie S, Dragovich PS, Chen J, Fauber BP, Boggs J, Corson LB, Ding CZ, Eigenbrot C, Ge H, Ho Q, Lai KW, Ma S, Malek S, Peterson D, Purkey HE, Robarge K, Salphati L, Sideris S, Ultsch M, VanderPorten E, Wei B, Xu Q, Yen I, Yue Q, Zhang H, Zhang X, and Zhou A
- Subjects
- Animals, Crystallography, X-Ray, Dogs, Enzyme Inhibitors metabolism, Enzyme Inhibitors pharmacology, Humans, L-Lactate Dehydrogenase metabolism, Madin Darby Canine Kidney Cells, Enzyme Inhibitors chemical synthesis, L-Lactate Dehydrogenase antagonists & inhibitors
- Abstract
Optimization of 5-(2,6-dichlorophenyl)-3-hydroxy-2-mercaptocyclohex-2-enone using structure-based design strategies resulted in inhibitors with considerable improvement in biochemical potency against human lactate dehydrogenase A (LDHA). These potent inhibitors were typically selective for LDHA over LDHB isoform (4–10 fold) and other structurally related malate dehydrogenases, MDH1 and MDH2 (>500 fold). An X-ray crystal structure of enzymatically most potent molecule bound to LDHA revealed two additional interactions associated with enhanced biochemical potency.
- Published
- 2015
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- View/download PDF
37. Need for studies to evaluate the role of endoscopic third ventriculostomy for post-operative hydrocephalus in Chiari I malformation.
- Author
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Vaqas B and Peterson D
- Subjects
- Female, Humans, Male, Arnold-Chiari Malformation surgery, Decompressive Craniectomy methods, Foramen Magnum surgery
- Published
- 2015
- Full Text
- View/download PDF
38. Identification of 3,6-disubstituted dihydropyrones as inhibitors of human lactate dehydrogenase.
- Author
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Fauber BP, Dragovich PS, Chen J, Corson LB, Ding CZ, Eigenbrot C, Labadie S, Malek S, Peterson D, Purkey HE, Robarge K, Sideris S, Ultsch M, Wei B, Yen I, Yue Q, and Zhou A
- Subjects
- Binding Sites, Crystallography, X-Ray, Humans, L-Lactate Dehydrogenase metabolism, Models, Molecular, Molecular Structure, Structure-Activity Relationship, Enzyme Inhibitors chemical synthesis, Enzyme Inhibitors pharmacology, L-Lactate Dehydrogenase antagonists & inhibitors, Pyrones chemical synthesis, Pyrones pharmacology
- Abstract
A series of 3,6-disubstituted dihydropyrones were identified as inhibitors of human lactate dehydrogenase (LDH)-A. Structure activity relationships were explored and a series of 6,6-spiro analogs led to improvements in LDHA potency (IC50 <350 nM). An X-ray crystal structure of an improved compound bound to human LDHA was obtained and it illustrated additional opportunities to enhance the potency of these compounds, resulting in the identification of 51 (IC50=30 nM)., (Copyright © 2014 Elsevier Ltd. All rights reserved.)
- Published
- 2014
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39. Identification of substituted 3-hydroxy-2-mercaptocyclohex-2-enones as potent inhibitors of human lactate dehydrogenase.
- Author
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Dragovich PS, Fauber BP, Boggs J, Chen J, Corson LB, Ding CZ, Eigenbrot C, Ge H, Giannetti AM, Hunsaker T, Labadie S, Li C, Liu Y, Liu Y, Ma S, Malek S, Peterson D, Pitts KE, Purkey HE, Robarge K, Salphati L, Sideris S, Ultsch M, VanderPorten E, Wang J, Wei B, Xu Q, Yen I, Yue Q, Zhang H, Zhang X, and Zhou A
- Subjects
- Administration, Oral, Animals, Cyclohexanones administration & dosage, Cyclohexanones chemistry, Dose-Response Relationship, Drug, Enzyme Inhibitors administration & dosage, Enzyme Inhibitors chemistry, High-Throughput Screening Assays, Humans, L-Lactate Dehydrogenase metabolism, Models, Molecular, Molecular Structure, Rats, Structure-Activity Relationship, Sulfhydryl Compounds administration & dosage, Sulfhydryl Compounds chemistry, Cyclohexanones pharmacology, Enzyme Inhibitors pharmacology, L-Lactate Dehydrogenase antagonists & inhibitors, Sulfhydryl Compounds pharmacology
- Abstract
A novel class of 3-hydroxy-2-mercaptocyclohex-2-enone-containing inhibitors of human lactate dehydrogenase (LDH) was identified through a high-throughput screening approach. Biochemical and surface plasmon resonance experiments performed with a screening hit (LDHA IC50=1.7 μM) indicated that the compound specifically associated with human LDHA in a manner that required simultaneous binding of the NADH co-factor. Structural variation of this screening hit resulted in significant improvements in LDHA biochemical inhibition activity (best IC50=0.18 μM). Two crystal structures of optimized compounds bound to human LDHA were obtained and explained many of the observed structure-activity relationships. In addition, an optimized inhibitor exhibited good pharmacokinetic properties after oral administration to rats (F=45%)., (Copyright © 2014 Elsevier Ltd. All rights reserved.)
- Published
- 2014
- Full Text
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40. Parietal skull reconstruction using immediate PEEK cranioplasty following resection for craniofacial fibrous dysplasia.
- Author
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Coulter C, Richards R, Peterson D, and Collier J
- Subjects
- Benzophenones, Biocompatible Materials, Female, Humans, Ketones, Middle Aged, Polyethylene Glycols, Polymers, Fibrous Dysplasia, Polyostotic surgery, Parietal Bone surgery, Prostheses and Implants, Sphenoid Bone surgery
- Published
- 2014
- Full Text
- View/download PDF
41. Closed-loop brain-machine-body interfaces for noninvasive rehabilitation of movement disorders.
- Author
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Broccard FD, Mullen T, Chi YM, Peterson D, Iversen JR, Arnold M, Kreutz-Delgado K, Jung TP, Makeig S, Poizner H, Sejnowski T, and Cauwenberghs G
- Subjects
- Animals, Brain physiology, Feedback, Physiological, Humans, Neuronal Plasticity, Movement Disorders therapy
- Abstract
Traditional approaches for neurological rehabilitation of patients affected with movement disorders, such as Parkinson's disease (PD), dystonia, and essential tremor (ET) consist mainly of oral medication, physical therapy, and botulinum toxin injections. Recently, the more invasive method of deep brain stimulation (DBS) showed significant improvement of the physical symptoms associated with these disorders. In the past several years, the adoption of feedback control theory helped DBS protocols to take into account the progressive and dynamic nature of these neurological movement disorders that had largely been ignored so far. As a result, a more efficient and effective management of PD cardinal symptoms has emerged. In this paper, we review closed-loop systems for rehabilitation of movement disorders, focusing on PD, for which several invasive and noninvasive methods have been developed during the last decade, reducing the complications and side effects associated with traditional rehabilitation approaches and paving the way for tailored individual therapeutics. We then present a novel, transformative, noninvasive closed-loop framework based on force neurofeedback and discuss several future developments of closed-loop systems that might bring us closer to individualized solutions for neurological rehabilitation of movement disorders.
- Published
- 2014
- Full Text
- View/download PDF
42. Dose-response and efficacy of spinal manipulation for care of chronic low back pain: a randomized controlled trial.
- Author
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Haas M, Vavrek D, Peterson D, Polissar N, and Neradilek MB
- Subjects
- Adult, Female, Humans, Male, Middle Aged, Treatment Outcome, Low Back Pain therapy, Manipulation, Spinal methods
- Abstract
Background Context: There have been no full-scale trials of the optimal number of visits for the care of any condition with spinal manipulation., Purpose: To identify the dose-response relationship between visits to a chiropractor for spinal manipulation and chronic low back pain (cLBP) outcomes and to determine the efficacy of manipulation by comparison with a light massage control., Study Design/setting: Practice-based randomized controlled trial., Patient Sample: Four hundred participants with cLBP., Outcome Measures: The primary cLBP outcomes were the 100-point modified Von Korff pain intensity and functional disability scales evaluated at the 12- and 24-week primary end points. Secondary outcomes included days with pain and functional disability, pain unpleasantness, global perceived improvement, medication use, and general health status., Methods: One hundred participants with cLBP were randomized to each of four dose levels of care: 0, 6, 12, or 18 sessions of spinal manipulation from a chiropractor. Participants were treated three times per week for 6 weeks. At sessions when manipulation was not assigned, they received a focused light massage control. Covariate-adjusted linear dose effects and comparisons with the no-manipulation control group were evaluated at 6, 12, 18, 24, 39, and 52 weeks., Results: For the primary outcomes, mean pain and disability improvement in the manipulation groups were 20 points by 12 weeks and sustainable to 52 weeks. Linear dose-response effects were small, reaching about two points per six manipulation sessions at 12 and 52 weeks for both variables (p<.025). At 12 weeks, the greatest differences from the no-manipulation control were found for 12 sessions (8.6 pain and 7.6 disability points, p<.025); at 24 weeks, differences were negligible; and at 52 weeks, the greatest group differences were seen for 18 visits (5.9 pain and 8.8 disability points, p<.025)., Conclusions: The number of spinal manipulation visits had modest effects on cLBP outcomes above those of 18 hands-on visits to a chiropractor. Overall, 12 visits yielded the most favorable results but was not well distinguished from other dose levels., (Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.)
- Published
- 2014
- Full Text
- View/download PDF
43. The cancer stem cell marker aldehyde dehydrogenase is required to maintain a drug-tolerant tumor cell subpopulation.
- Author
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Raha D, Wilson TR, Peng J, Peterson D, Yue P, Evangelista M, Wilson C, Merchant M, and Settleman J
- Subjects
- Aldehyde Dehydrogenase antagonists & inhibitors, Animals, Apoptosis drug effects, Cell Line, Tumor, Cell Survival, Crizotinib, DNA Damage, ErbB Receptors antagonists & inhibitors, Erlotinib Hydrochloride, Humans, Mice, Mice, Nude, Oxidative Stress, Protein Kinase Inhibitors pharmacology, Pyrazoles pharmacology, Pyridines pharmacology, Quinazolines pharmacology, RNA Interference, RNA, Small Interfering, Reactive Oxygen Species metabolism, Xenograft Model Antitumor Assays, Aldehyde Dehydrogenase metabolism, Disulfiram pharmacology, Drug Resistance, Neoplasm, Neoplastic Stem Cells drug effects, Neoplastic Stem Cells enzymology
- Abstract
Selective kinase inhibitors have emerged as an important class of cancer therapeutics, and several such drugs are now routinely used to treat advanced-stage disease. However, their clinical benefit is typically short-lived because of the relatively rapid acquisition of drug resistance following treatment response. Accumulating preclinical and clinical data point to a role for a heterogeneous response to treatment within a subpopulation of tumor cells that are intrinsically drug-resistant, such as cancer stem cells. We have previously described an epigenetically determined reversibly drug-tolerant subpopulation of cancer cells that share some properties with cancer stem cells. Here, we define a requirement for the previously established cancer stem cell marker ALDH (aldehyde dehydrogenase) in the maintenance of this drug-tolerant subpopulation. We find that ALDH protects the drug-tolerant subpopulation from the potentially toxic effects of elevated levels of reactive oxygen species (ROS) in these cells, and pharmacologic disruption of ALDH activity leads to accumulation of ROS to toxic levels, consequent DNA damage, and apoptosis specifically within the drug-tolerant subpopulation. Combining ALDH inhibition with other kinase-directed treatments delayed treatment relapse in vitro and in vivo, revealing a novel combination treatment strategy for cancers that might otherwise rapidly relapse following single-agent therapy., (©2014 American Association for Cancer Research.)
- Published
- 2014
- Full Text
- View/download PDF
44. Variants in PPP3R1 and MAPT are associated with more rapid functional decline in Alzheimer's disease: the Cache County Dementia Progression Study.
- Author
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Peterson D, Munger C, Crowley J, Corcoran C, Cruchaga C, Goate AM, Norton MC, Green RC, Munger RG, Breitner JC, Welsh-Bohmer KA, Lyketsos C, Tschanz J, and Kauwe JS
- Subjects
- Aged, Aged, 80 and over, Disease Progression, Female, Follow-Up Studies, Genetic Predisposition to Disease, Genotyping Techniques, Heterozygote, Humans, Linear Models, Male, Models, Genetic, Risk, Severity of Illness Index, Time Factors, Alzheimer Disease genetics, Alzheimer Disease physiopathology, Calcineurin genetics, Polymorphism, Single Nucleotide, tau Proteins genetics
- Abstract
Background: Single-nucleotide polymorphisms (SNPs) located in the gene encoding the regulatory subunit of the protein phosphatase 2B (PPP3R1, rs1868402) and the microtubule-associated protein tau (MAPT, rs3785883) gene were recently associated with higher cerebrospinal fluid (CSF) tau levels in samples from the Knight Alzheimer's Disease Research Center at Washington University (WU) and Alzheimer's Disease Neuroimaging Initiative (ADNI). In these same samples, these SNPs were also associated with faster functional decline, or progression of Alzheimer's disease (AD) as measured by the Clinical Dementia Rating sum of boxes scores (CDR-sb). We attempted to validate the latter association in an independent, population-based sample of incident AD cases from the Cache County Dementia Progression Study (DPS)., Methods: All 92 AD cases from the DPS with a global CDR-sb ≤1 (mild) at initial clinical assessment who were later assessed on CDR-sb data on at least two other time points were genotyped at the two SNPs of interest (rs1868402 and rs3785883). We used linear mixed models to estimate associations between these SNPs and CDR-sb trajectory. All analyses were performed using Proc Mixed in SAS., Results: Although we observed no association between rs3785883 or rs1868402 alone and change in CDR-sb (P > .10), there was a significant association between a combined genotype model and change in CDR-sb: carriers of the high-risk genotypes at both loci progressed >2.9 times faster than noncarriers (P = .015). When data from DPS were combined with previously published data from WU and ADNI, change in CDR-sb was 30% faster for each copy of the high-risk allele at rs3785883 (P = .0082) and carriers of both high-risk genotypes at both loci progressed 6 times faster (P < .0001) than all others combined., Conclusions: We replicate a previous report by Cruchaga et al that specific variations in rs3785883 and rs1868402 are associated with accelerated progression of AD. Further characterization of this association will provide a better understanding of how genetic factors influence the rate of progression of AD and could provide novel insights into preventative and therapeutic strategies., (Copyright © 2014 The Alzheimer's Association. Published by Elsevier Inc. All rights reserved.)
- Published
- 2014
- Full Text
- View/download PDF
45. AKT-induced tamoxifen resistance is overturned by RRM2 inhibition.
- Author
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Shah KN, Mehta KR, Peterson D, Evangelista M, Livesey JC, and Faridi JS
- Subjects
- Animals, Antineoplastic Agents, Hormonal pharmacology, Breast Neoplasms genetics, Breast Neoplasms metabolism, Breast Neoplasms pathology, Cell Growth Processes drug effects, Cell Movement drug effects, Cell Movement physiology, Drug Resistance, Neoplasm, Estrogen Receptor alpha biosynthesis, Female, Humans, Isoenzymes, MCF-7 Cells, Mice, Neoplasms, Hormone-Dependent drug therapy, Neoplasms, Hormone-Dependent genetics, Neoplasms, Hormone-Dependent metabolism, Neoplasms, Hormone-Dependent pathology, Signal Transduction, Xenograft Model Antitumor Assays, Breast Neoplasms drug therapy, Proto-Oncogene Proteins c-akt metabolism, Ribonucleoside Diphosphate Reductase antagonists & inhibitors, Tamoxifen pharmacology
- Abstract
Unlabelled: Acquired tamoxifen resistance develops in the majority of hormone-responsive breast cancers and frequently involves overexpression of the PI3K/AKT axis. Here, breast cancer cells with elevated endogenous AKT or overexpression of activated AKT exhibited tamoxifen-stimulated cell proliferation and enhanced cell motility. To gain mechanistic insight on AKT-induced endocrine resistance, gene expression profiling was performed to determine the transcripts that are differentially expressed post-tamoxifen therapy under conditions of AKT overexpression. Consistent with the biologic outcome, many of these transcripts function in cell proliferation and cell motility networks and were quantitatively validated in a larger panel of breast cancer cells. Moreover, ribonucleotide reductase M2 (RRM2) was revealed as a key contributor to AKT-induced tamoxifen resistance. Inhibition of RRM2 by RNA interference (RNAi)-mediated approaches significantly reversed the tamoxifen-resistant cell growth, inhibited cell motility, and activated DNA damage and proapoptotic pathways. In addition, treatment of tamoxifen-resistant breast cancer cells with the small molecule RRM inhibitor didox significantly reduced in vitro and in vivo growth. Thus, AKT-expressing breast cancer cells upregulate RRM2 expression, leading to increased DNA repair and protection from tamoxifen-induced apoptosis., Implications: These findings identify RRM2 as an AKT-regulated gene, which plays a role in tamoxifen resistance and may prove to be a novel target for effective diagnostic and preventative strategies.
- Published
- 2014
- Full Text
- View/download PDF
46. Deformable versus rigid registration of PET/CT images for radiation treatment planning of head and neck and lung cancer patients: a retrospective dosimetric comparison.
- Author
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Fortin D, Basran PS, Berrang T, Peterson D, and Wai ES
- Subjects
- Aged, Carcinoma, Non-Small-Cell Lung pathology, Head and Neck Neoplasms pathology, Humans, Image Processing, Computer-Assisted methods, Lung Neoplasms pathology, Middle Aged, Multimodal Imaging, Radiometry, Radiotherapy Dosage, Retrospective Studies, Software, Tumor Burden, Carcinoma, Non-Small-Cell Lung radiotherapy, Head and Neck Neoplasms radiotherapy, Lung Neoplasms radiotherapy, Positron-Emission Tomography, Radiotherapy Planning, Computer-Assisted methods, Tomography, X-Ray Computed
- Abstract
Background: The purpose of this study is to evaluate the clinical impact of using deformable registration in tumor volume definition between separately acquired PET/CT and planning CT images., Methods: Ten lung and 10 head and neck cancer patients were retrospectively selected. PET/CT images were registered with planning CT scans using commercially available software. Radiation oncologists defined two sets of gross tumor volumes based on either rigidly or deformably registered PET/CT images, and properties of these volumes were then compared., Results: The average displacement between rigid and deformable gross tumor volumes was 1.8 mm (0.7 mm) with a standard deviation of 1.0 mm (0.6 mm) for the head and neck (lung) cancer subjects. The Dice similarity coefficients ranged from 0.76-0.92 and 0.76-0.97 for the head and neck and lung subjects, respectively, indicating conformity. All gross tumor volumes received at least 95% of the prescribed dose to 99% of their volume. Differences in the mean radiation dose delivered to the gross tumor volumes were at most 2%. Differences in the fraction of the tumor volumes receiving 100% of the radiation dose were at most 5%., Conclusions: The study revealed limitations in the commercial software used to perform deformable registration. Unless significant anatomical differences between PET/CT and planning CT images are present, deformable registration was shown to be of marginal value when delineating gross tumor volumes.
- Published
- 2014
- Full Text
- View/download PDF
47. Stereotactic radiosurgery in the treatment of brain metastases: the current evidence.
- Author
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Lippitz B, Lindquist C, Paddick I, Peterson D, O'Neill K, and Beaney R
- Subjects
- Brain Neoplasms mortality, Brain Neoplasms secondary, Combined Modality Therapy, Humans, Quality of Life, Treatment Outcome, Whole-Body Irradiation, Brain Neoplasms surgery, Radiosurgery
- Abstract
Chemotherapy has made substantial progress in the therapy of systemic cancer, but the pharmacological efficacy is insufficient in the treatment of brain metastases. Fractionated whole brain radiotherapy (WBRT) has been a standard treatment of brain metastases, but provides limited local tumor control and often unsatisfactory clinical results. Stereotactic radiosurgery using Gamma Knife, Linac or Cyberknife has overcome several of these limitations, which has influenced recent treatment recommendations. This present review summarizes the current literature of single session radiosurgery concerning survival and quality of life, specific responses, tumor volumes and numbers, about potential treatment combinations and radioresistant metastases. Gamma Knife and Linac based radiosurgery provide consistent results with a reproducible local tumor control in both single and multiple brain metastases. Ideally minimum doses of ≥18Gy are applied. Reported local control rates were 90-94% for breast cancer metastases and 81-98% for brain metastases of lung cancer. Local tumor control rates after radiosurgery of otherwise radioresistant brain metastases were 73-90% for melanoma and 83-96% for renal cell cancer. Currently, there is a tendency to treat a larger number of brain metastases in a single radiosurgical session, since numerous studies document high local tumor control after radiosurgical treatment of >3 brain metastases. New remote brain metastases are reported in 33-42% after WBRT and in 39-52% after radiosurgery, but while WBRT is generally applied only once, radiosurgery can be used repeatedly for remote recurrences or new metastases after WBRT. Larger metastases (>8-10cc) should be removed surgically, but for smaller metastases Gamma Knife radiosurgery appears to be equally effective as surgical tumor resection (level I evidence). Radiosurgery avoids the impairments in cognition and quality of life that can be a consequence of WBRT (level I evidence). High local efficacy, preservation of cerebral functions, short hospitalization and the option to continue a systemic chemotherapy are factors in favor of a minimally invasive approach with stereotactic radiosurgery., (Copyright © 2013 The Authors. Published by Elsevier Ltd.. All rights reserved.)
- Published
- 2014
- Full Text
- View/download PDF
48. Identification of 2-amino-5-aryl-pyrazines as inhibitors of human lactate dehydrogenase.
- Author
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Fauber BP, Dragovich PS, Chen J, Corson LB, Ding CZ, Eigenbrot C, Giannetti AM, Hunsaker T, Labadie S, Liu Y, Liu Y, Malek S, Peterson D, Pitts K, Sideris S, Ultsch M, VanderPorten E, Wang J, Wei B, Yen I, and Yue Q
- Subjects
- Animals, Binding Sites, Crystallography, X-Ray, Enzyme Inhibitors chemical synthesis, Enzyme Inhibitors pharmacokinetics, Half-Life, Humans, L-Lactate Dehydrogenase metabolism, Male, Microsomes, Liver metabolism, Protein Structure, Tertiary, Pyrazines chemical synthesis, Pyrazines pharmacokinetics, Rats, Rats, Sprague-Dawley, Structure-Activity Relationship, Enzyme Inhibitors chemistry, L-Lactate Dehydrogenase antagonists & inhibitors, Pyrazines chemistry
- Abstract
A 2-amino-5-aryl-pyrazine was identified as an inhibitor of human lactate dehydrogenase A (LDHA) via a biochemical screening campaign. Biochemical and biophysical experiments demonstrated that the compound specifically interacted with human LDHA. Structural variation of the screening hit resulted in improvements in LDHA biochemical inhibition and pharmacokinetic properties. A crystal structure of an improved compound bound to human LDHA was also obtained and it explained many of the observed structure-activity relationships., (Copyright © 2013 Elsevier Ltd. All rights reserved.)
- Published
- 2013
- Full Text
- View/download PDF
49. Identification of substituted 2-thio-6-oxo-1,6-dihydropyrimidines as inhibitors of human lactate dehydrogenase.
- Author
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Dragovich PS, Fauber BP, Corson LB, Ding CZ, Eigenbrot C, Ge H, Giannetti AM, Hunsaker T, Labadie S, Liu Y, Malek S, Pan B, Peterson D, Pitts K, Purkey HE, Sideris S, Ultsch M, VanderPorten E, Wei B, Xu Q, Yen I, Yue Q, Zhang H, and Zhang X
- Subjects
- Binding Sites, Crystallography, X-Ray, Enzyme Inhibitors chemical synthesis, Enzyme Inhibitors metabolism, Humans, Hydrogen Bonding, L-Lactate Dehydrogenase metabolism, Magnetic Resonance Spectroscopy, NAD metabolism, Protein Binding, Protein Structure, Tertiary, Pyrimidines chemical synthesis, Pyrimidines metabolism, Structure-Activity Relationship, Surface Plasmon Resonance, Enzyme Inhibitors chemistry, L-Lactate Dehydrogenase antagonists & inhibitors, Pyrimidines chemistry
- Abstract
A novel 2-thio-6-oxo-1,6-dihydropyrimidine-containing inhibitor of human lactate dehydrogenase (LDH) was identified by high-throughput screening (IC50=8.1 μM). Biochemical, surface plasmon resonance, and saturation transfer difference NMR experiments indicated that the compound specifically associated with human LDHA in a manner that required simultaneous binding of the NADH co-factor. Structural variation of the screening hit resulted in significant improvements in LDHA biochemical inhibition activity (best IC50=0.48 μM). A crystal structure of an optimized compound bound to human LDHA was obtained and explained many of the observed structure-activity relationships., (Copyright © 2013 Elsevier Ltd. All rights reserved.)
- Published
- 2013
- Full Text
- View/download PDF
50. A simple high-content cell cycle assay reveals frequent discrepancies between cell number and ATP and MTS proliferation assays.
- Author
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Chan GK, Kleinheinz TL, Peterson D, and Moffat JG
- Subjects
- Adenosine Triphosphate, Cell Cycle physiology, Cell Line, Tumor, Dose-Response Relationship, Drug, Humans, Luminescent Measurements, Tetrazolium Salts, Antineoplastic Agents pharmacology, Cell Count methods, Cell Cycle drug effects, Cell Proliferation drug effects, Drug Discovery methods, High-Throughput Screening Assays methods
- Abstract
In order to efficiently characterize both antiproliferative potency and mechanism of action of small molecules targeting the cell cycle, we developed a high-throughput image-based assay to determine cell number and cell cycle phase distribution. Using this we profiled the effects of experimental and approved anti-cancer agents with a range mechanisms of action on a set of cell lines, comparing direct cell counting versus two metabolism-based cell viability/proliferation assay formats, ATP-dependent bioluminescence, MTS (3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium) reduction, and a whole-well DNA-binding dye fluorescence assay. We show that, depending on compound mechanisms of action, the metabolism-based proxy assays are frequently prone to 1) significant underestimation of compound potency and efficacy, and 2) non-monotonic dose-response curves due to concentration-dependent phenotypic 'switching'. In particular, potency and efficacy of DNA synthesis-targeting agents such as gemcitabine and etoposide could be profoundly underestimated by ATP and MTS-reduction assays. In the same image-based assay we showed that drug-induced increases in ATP content were associated with increased cell size and proportionate increases in mitochondrial content and respiratory flux concomitant with cell cycle arrest. Therefore, differences in compound mechanism of action and cell line-specific responses can yield significantly misleading results when using ATP or tetrazolium-reduction assays as a proxy for cell number when screening compounds for antiproliferative activity or profiling panels of cell lines for drug sensitivity.
- Published
- 2013
- Full Text
- View/download PDF
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