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Johnson N, Ebersole JL, Kryscio RJ, Danaher RJ, Dawson D, Al-Sabbagh M, Miller CS. Rapid assessment of salivary MMP-8 and periodontal disease using lateral flow immunoassay. Oral Dis 2016; 22:681-7. [PMID: 27273425 DOI: 10.1111/odi.12521] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2016] [Revised: 05/04/2016] [Accepted: 06/03/2016] [Indexed: 12/26/2022]
Abstract
OBJECTIVE The objective of this study was to determine the efficacy of a novel point-of-care immunoflow device (POCID) for detecting matrix metalloproteinase (MMP)-8 concentrations in oral fluids in comparison with a gold standard laboratory-based immunoassay. METHODS Oral rinse fluid and whole expectorated saliva samples were collected from 41 participants clinically classified as periodontally healthy or diseased. Samples were analyzed for MMP-8 by Luminex immunoassay and POCID. Photographed POCID results were assessed by optical scan and visually by two examiners. Data were analyzed by Pearson's correlation and receiver-operating characteristics. RESULTS MMP-8 was readily detected by the POCID, and concentrations correlated well with Luminex for both saliva and rinse fluids (r = 0.57-0.93). Thresholds that distinguished periodontitis from health were delineated from both the optical scans and visual reads of the POCID (sensitivity: 0.7-0.9, specificity: 0.5-0.7; P < 0.05). CONCLUSIONS Performance of this POCID for detecting MMP-8 in oral rinse fluid or saliva was excellent. These findings help demonstrate the utility of salivary biomarkers for distinguishing periodontal disease from health using a rapid point-of-care approach.
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Simpkins C, Cota AM, Johnson N. Lateral cutaneous nerve of thigh injury following TEPP laparoscopic inguinal hernia repair. Scott Med J 2016. [DOI: 10.1258/rsmsmj.52.4.54e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
A 40-year-old gentleman underwent a routine TEPP (trans-extraperitoneal) procedure without the use of staples to fix the mesh. He presented with symptoms of lateral cutaneous nerve of the thigh injury. We present this rare complication and its management.
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Farrier AJ, Sanchez Franco LC, Shoaib A, Gulati V, Johnson N, Uzoigwe CE, Choudhury MZ. New anti-resorptives and antibody mediated anti-resorptive therapy. Bone Joint J 2016; 98-B:160-5. [PMID: 26850419 DOI: 10.1302/0301-620x.98b2.36161] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
UNLABELLED The ageing population and an increase in both the incidence and prevalence of cancer pose a healthcare challenge, some of which is borne by the orthopaedic community in the form of osteoporotic fractures and metastatic bone disease. In recent years there has been an increasing understanding of the pathways involved in bone metabolism relevant to osteoporosis and metastases in bone. Newer therapies may aid the management of these problems. One group of drugs, the antibody mediated anti-resorptive therapies (AMARTs) use antibodies to block bone resorption pathways. This review seeks to present a synopsis of the guidelines, pharmacology and potential pathophysiology of AMARTs and other new anti-resorptive drugs. We evaluate the literature relating to AMARTs and new anti-resorptives with special attention on those approved for use in clinical practice. Denosumab, a monoclonal antibody against Receptor Activator for Nuclear Factor Kappa-B Ligand. It is the first AMART approved by the National Institute for Health and Clinical Excellence and the US Food and Drug Administration. Other novel anti-resorptives awaiting approval for clinical use include Odanacatib. Denosumab is indicated for the treatment of osteoporosis and prevention of the complications of bone metastases. Recent evidence suggests, however, that denosumab may have an adverse event profile similar to bisphosphonates, including atypical femoral fractures. It is, therefore, essential that orthopaedic surgeons are conversant with these medications and their safe usage. TAKE HOME MESSAGE Denosumab has important orthopaedic indications and has been shown to significantly reduce patient morbidity in osteoporosis and metastatic bone disease.
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Miles T, Johnson N, Powell M. Fat is a realist's issue. BJOG 2016; 123:299. [PMID: 26839973 DOI: 10.1111/1471-0528.13793] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Parker H, O'Connor H, Cohn J, Garg M, Caterson I, George J, Johnson N. Effect of combined fish oil plus coenzyme Q 10 supplementation on Omega-3 Index and cardiovascular risk markers in overweight men. JOURNAL OF NUTRITION & INTERMEDIARY METABOLISM 2016. [DOI: 10.1016/j.jnim.2015.12.200] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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81
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Johnson N. Two large randomised trials show ovarian cancer screening has minimal impact on survival. BJOG 2016; 125:524-525. [DOI: 10.1111/1471-0528.14052] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/29/2016] [Indexed: 11/30/2022]
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82
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Norris C, Johnson N, Hardwicke-Brown E, McEwan M, Pelletier R, Pilote L. Sex Differences in Health Status May be Better Explained by Gender Related Characteristics, than Biological Sex Characteristics. Can J Cardiol 2016. [DOI: 10.1016/j.cjca.2016.02.044] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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83
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Kataoka M, Johnson N, Emary C, See P, Griffiths JP, Jones GAC, Farrer I, Ritchie DA, Pepper M, Janssen TJBM. Time-of-Flight Measurements of Single-Electron Wave Packets in Quantum Hall Edge States. PHYSICAL REVIEW LETTERS 2016; 116:126803. [PMID: 27058091 DOI: 10.1103/physrevlett.116.126803] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2015] [Indexed: 06/05/2023]
Abstract
We report time-of-flight measurements on electrons traveling in quantum Hall edge states. Hot-electron wave packets are emitted one per cycle into edge states formed along a depleted sample boundary. The electron arrival time is detected by driving a detector barrier with a square wave that acts as a shutter. By adding an extra path using a deflection barrier, we measure a delay in the arrival time, from which the edge-state velocity v is deduced. We find that v follows 1/B dependence, in good agreement with the E[over →]×B[over →] drift. The edge potential is estimated from the energy dependence of v using a harmonic approximation.
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Keating S, Hackett D, Way K, Parker H, Sainsbury A, Baker M, Chuter V, Caterson I, Johnson N, George J. Effect of progressive resistance training on liver fat in overweight adults: Moving beyond weight loss. J Sci Med Sport 2015. [DOI: 10.1016/j.jsams.2015.12.358] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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85
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Johnson N, Keating S, Way K, Sainsbury A, Baker M, Chuter V, Caterson I, George J. Exercise and visceral fat loss: is waist circumference a useful predictor? J Sci Med Sport 2015. [DOI: 10.1016/j.jsams.2015.12.179] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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86
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Pascal J, Johnson N, Dickson-Swift V, McGrath P, Dangerfield F. Understanding receptivity to informal supportive cancer care in regional and rural Australia: a Heideggerian analysis. Eur J Cancer Care (Engl) 2015; 25:381-90. [PMID: 26047366 DOI: 10.1111/ecc.12337] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/27/2015] [Indexed: 11/30/2022]
Abstract
The concept of receptivity is a new way of understanding the personal and social factors that affect a person living with and beyond cancer, and how these factors influence access to formal supportive care service provision and planning. This article contributes to new knowledge through applying the concept of receptivity to informal supportive cancer care in regional Australia. Literature indicates that a cancer diagnosis is a life-changing experience, particularly in regional communities, where survival rates are lower and there are significant barriers to accessing services. Heideggerian phenomenology informed the design of the study and allowed for a rich and nuanced understanding of participants lived experiences of informal supportive cancer care. These experiences were captured using in-depth interviews, which were subsequently thematically analysed. Nineteen participants were recruited from across regional Victoria, Australia. Participants self-reported a range of stages and types of cancer. Significantly, findings revealed that most participants were not referred to, and did not seek, formal supportive care. Instead, they were receptive to informal supportive care. Understanding receptivity and the role of anxiety and fear of death has implications for partners, family, community members, as well as professionals working with people with living with and beyond cancer.
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Woodhouse N, DiBiase A, Johnson N, Slipper C, Grant J, Alsaleh M, Donaldson A, Cobourne M. Supplemental Vibrational Force During Orthodontic Alignment. J Dent Res 2015; 94:682-9. [DOI: 10.1177/0022034515576195] [Citation(s) in RCA: 75] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
This prospective 3-arm parallel-group randomized clinical trial investigated the effect of supplemental vibrational force on rate of orthodontic tooth alignment with fixed appliances. Eighty-one subjects (40 males, 41 females; mean age, 14.1 y) undergoing first premolar extraction-based fixed appliance treatment were randomly allocated to treatment supplemented with daily use (20 min) of a removable intraoral vibrational device (AcceleDent; OrthoAccel Technologies Inc.; n = 29), an identical nonfunctional (sham) device ( n = 25), or fixed appliances only ( n = 27). Mandibular study casts were taken at baseline (treatment start: placement of 0.014-in. nickel-titanium arch wire), initial alignment (0.018-in. nickel-titanium arch wire), and final alignment (0.019 x 0.025–in. stainless steel arch wire). Overall mean irregularity index in the mandibular arch at baseline was 8.5 ± 3.8 mm (95% CI, 7.6 to 9.3) with no significant difference between groups ( P = 0.73). For the total sample, mean irregularity index at initial alignment was 2.7 ± 2.8 mm (95% CI, 2.2 to 3.4) with no significant difference between groups ( P = 0.40). Mean time from baseline to initial alignment was 59 ± 25 d (95% CI, 54.5 to 65.6); from initial to final alignment, 150 ± 62.5 d (95% CI, 136 to 165); and baseline to final alignment, 209 ± 65 d (95% CI, 195 to 224). Kaplan-Meier analysis demonstrated that patterns of alignment were not significantly different among the 3 groups ( P = 0.66). Multivariate linear regression for initial and overall alignment rates using initial irregularity index as the covariate showed no significant differences among groups. The most important influence on both initial and overall rates of alignment was initial irregularity ( P = 0.1 × 10−4). This prospective randomized clinical trial found no evidence that supplemental vibrational force can significantly increase the rate of initial tooth movement or reduce the amount of time required to achieve final alignment when used in conjunction with a preadjusted edgewise fixed appliance ( ClinicalTrials.gov NCT02314975).
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Mahadevan D, Johnson N, Pandey M, Chandler J, Cooke L. Novel mutational profiles in relapsed/refractory advanced cancer patients' pre- and post-targeted therapy. Ann Oncol 2015. [DOI: 10.1093/annonc/mdv097.6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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89
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Mackenzie-Impoinvil L, Impoinvil DE, Galbraith SE, Dillon RJ, Ranson H, Johnson N, Fooks AR, Solomon T, Baylis M. Evaluation of a temperate climate mosquito, Ochlerotatus detritus (=Aedes detritus), as a potential vector of Japanese encephalitis virus. MEDICAL AND VETERINARY ENTOMOLOGY 2015; 29:1-9. [PMID: 25087926 DOI: 10.1111/mve.12083] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2013] [Revised: 05/10/2014] [Accepted: 05/28/2014] [Indexed: 06/03/2023]
Abstract
The U.K. has not yet experienced a confirmed outbreak of mosquito-borne virus transmission to people or livestock despite numerous autochthonous epizootic and human outbreaks of mosquito-borne diseases on the European mainland. Indeed, whether or not British mosquitoes are competent to transmit arboviruses has not been established. Therefore, the competence of a local (temperate) British mosquito species, Ochlerotatus detritus (=Aedes detritus) (Diptera: Culicidae) for transmission of a member of the genus Flavivirus, Japanese encephalitis virus (JEV) as a model for mosquito-borne virus transmission was assessed. The JEV competence in a laboratory strain of Culex quinquefasciatus (Diptera: Culicidae), a previously incriminated JEV vector, was also evaluated as a positive control. Ochlerotatus detritus adults were reared from field-collected juvenile stages. In oral infection bioassays, adult females developed disseminated infections and were able to transmit virus as determined by the isolation of virus in saliva secretions. When pooled at 7-21 days post-infection, 13% and 25% of O. detritus were able to transmit JEV when held at 23 °C and 28 °C, respectively. Similar results were obtained for C. quinquefasciatus. To our knowledge, this study is the first to demonstrate that a British mosquito species, O. detritus, is a potential vector of an exotic flavivirus.
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Singewald T, Patel M, Racadio J, Johnson N, Aguado A, Nachabe R. Clinical relevance of ultra low-dose digital subtraction angiography in pediatric patients. J Vasc Interv Radiol 2015. [DOI: 10.1016/j.jvir.2014.12.096] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022] Open
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91
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Plotnikoff R, Costigan S, Short C, Grunseit A, James E, Johnson N, Bauman A, D’Este C, van der Ploeg H, Rhodes R. Factors associated with sitting time in adults with chronic disease or psychological distress: Findings from the 45 & Up Study. J Sci Med Sport 2014. [DOI: 10.1016/j.jsams.2014.11.158] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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92
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Soucheray M, Kikuchi E, Pulido I, Akbay E, Becker J, Christensen C, Johnson N, Patel T, Carretero J, Wong K, Shimamura T. 593 Strategies to overcome resistance to BET bromodomain inhibitor in KRAS/LKB1 mutant NSCLC. Eur J Cancer 2014. [DOI: 10.1016/s0959-8049(14)70719-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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93
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Mohammad H, Smitheman K, van Aller G, Cusan M, Kamat S, Liu Y, Johnson N, Hann C, Armstrong S, Kruger R. 212 Novel anti-tumor activity of targeted LSD1 inhibition by GSK2879552. Eur J Cancer 2014. [DOI: 10.1016/s0959-8049(14)70338-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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94
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Johnson S, Johnson N, Chi D, Primack B, Cruz C, Stover D, Greifenberg A, Cao S, O'Connor K, Baselga J, Balmaña J, Serra V, Geyer M, D'Andrea A, Lim E, Shapiro G. 238 Reversal of primary and acquired PARP-inhibitor resistance in BRCA-mutated triple-negative breast cancers by inhibition of transcriptional cyclin-dependent kinases (CDKs). Eur J Cancer 2014. [DOI: 10.1016/s0959-8049(14)70364-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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95
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Pascal J, Johnson N, Dickson-Swift V, Kenny A. Returning home: psychosocial care during the re-entry phase of cancer survivorship in rural Australia. Eur J Cancer Care (Engl) 2014; 24:39-49. [PMID: 25163537 DOI: 10.1111/ecc.12232] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/29/2014] [Indexed: 11/30/2022]
Abstract
The purpose of this research was to highlight gaps in formal psychosocial care for cancer survivors in rural communities. The study was conducted in rural Victoria, Australia, and involved interviews with people with various stages of cancer progression, cancer diagnoses and survival times, who were interviewed about their experiences of psychosocial cancer care. Interviews focused on their experience of psychosocial care and were audio-recorded and transcribed verbatim. Data were thematically analysed to identify key themes. Findings demonstrate that psychosocial care is essentially informal within the re-entry period after cancer diagnosis and treatment. Despite current Australian clinical guidelines on psychosocial care for people with cancer, which indicate the need for the provision of formal psychosocial care, participants in this study largely cared for themselves, or received informal support from family, friends and community members. Many psychosocial needs remained unmet and professional support was lacking. While this study was conducted in rural Australia, many of our findings have been echoed in studies from other countries. The findings have implications for treatment protocols and discharge planning, health professional-patient-family relationships, and the long-term well-being of cancer survivors living in rural communities. A model for understanding the experience of formal supportive care during the re-entry phase of survivorship is proposed.
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Fooks AR, Horton DL, Phipps LP, Mansfield KL, McCracken F, Jeffries CL, Johnson N, Wrigley S, Deuchande R, Toth B, Alzola R. Suspect West Nile encephalitis in a horse imported into the UK from Europe. VETERINARY RECORD CASE REPORTS 2014. [DOI: 10.1136/vetreccr-2014-000104] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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97
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Park JT, Johnson N, Liu S, Levesque M, Wang YJ, Ho H, Huso D, Maitra A, Parsons MJ, Prescott JD, Leach SD. Differential in vivo tumorigenicity of diverse KRAS mutations in vertebrate pancreas: A comprehensive survey. Oncogene 2014; 34:2801-6. [PMID: 25065594 PMCID: PMC4836617 DOI: 10.1038/onc.2014.223] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2014] [Revised: 06/09/2014] [Accepted: 06/15/2014] [Indexed: 12/30/2022]
Abstract
Somatic activation of the KRAS proto-oncogene is evident in almost all pancreatic cancers, and appears to represent an initiating event. These mutations occur primarily at codon 12 and less frequently at codons 13 and 61. While some studies have suggested that different KRAS mutations may have variable oncogenic properties, to date there has been no comprehensive functional comparison of multiple KRAS mutations in an in vivo vertebrate tumorigenesis system. We generated a Gal4/UAS-based zebrafish model of pancreatic tumorigenesis in which the pancreatic expression of UAS-regulated oncogenes is driven by a ptf1a:Gal4-VP16 driver line. This system allowed us to rapidly compare the ability of 12 different KRAS mutations (G12A, G12C, G12D, G12F, G12R, G12S, G12V, G13C, G13D, Q61L, Q61R, and A146T) to drive pancreatic tumorigenesis in vivo. Among fish injected with one of five KRAS mutations reported in other tumor types but not in human pancreatic cancer, 2/79 (0.25%) developed pancreatic tumors, with both tumors arising in fish injected with A146T. In contrast, among fish injected with one of seven KRAS mutations known to occur in human pancreatic cancer, 22/106 (20.8%) developed pancreatic cancer. All eight tumorigenic KRAS mutations were associated with downstream MAPK/ERK pathway activation in preneoplastic pancreatic epithelium, while non-tumorigenic mutations were not. These results suggest that the spectrum of KRAS mutations observed in human pancreatic cancer reflects selection based upon variable tumorigenic capacities, including the ability to activate MAPK/ERK signaling.
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98
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Odderson I, Bentley T, Wissel J, Dashtipour K, Johnson N, Evans C, Gillard P, Zorowitz R. Development of a picture guide to identify common postures of spasticity. Ann Phys Rehabil Med 2014. [DOI: 10.1016/j.rehab.2014.03.165] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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99
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Johnson N, Chang Z, Bravo Almeida C, Michel M, Iversen C, Callanan M. Evaluation of indirect impedance for measuring microbial growth in complex food matrices. Food Microbiol 2014; 42:8-13. [PMID: 24929710 DOI: 10.1016/j.fm.2014.02.014] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2013] [Revised: 02/13/2014] [Accepted: 02/17/2014] [Indexed: 10/25/2022]
Abstract
The suitability of indirect impedance to accurately measure microbial growth in real food matrices was investigated. A variety of semi-solid and liquid food products were inoculated with Bacillus cereus, Listeria monocytogenes, Staphylococcus aureus, Lactobacillus plantarum, Pseudomonas aeruginosa, Escherichia coli, Salmonella enteriditis, Candida tropicalis or Zygosaccharomyces rouxii and CO2 production was monitored using a conductimetric (Don Whitely R.A.B.I.T.) system. The majority (80%) of food and microbe combinations produced a detectable growth signal. The linearity of conductance responses in selected food products was investigated and a good correlation (R(2) ≥ 0.84) was observed between inoculum levels and times to detection. Specific growth rate estimations from the data were sufficiently accurate for predictive modeling in some cases. This initial evaluation of the suitability of indirect impedance to generate microbial growth data in complex food matrices indicates significant potential for the technology as an alternative to plating methods.
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Petibon Y, El Fakhri G, Nezafat R, Johnson N, Brady T, Ouyang J. Towards coronary plaque imaging using simultaneous PET-MR: a simulation study. Phys Med Biol 2014; 59:1203-22. [PMID: 24556608 DOI: 10.1088/0031-9155/59/5/1203] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Coronary atherosclerotic plaque rupture is the main cause of myocardial infarction and the leading killer in the US. Inflammation is a known bio-marker of plaque vulnerability and can be assessed non-invasively using fluorodeoxyglucose-positron emission tomography imaging (FDG-PET). However, cardiac and respiratory motion of the heart makes PET detection of coronary plaque very challenging. Fat surrounding coronary arteries allows the use of MRI to track plaque motion during simultaneous PET-MR examination. In this study, we proposed and assessed the performance of a fat-MR based coronary motion correction technique for improved FDG-PET coronary plaque imaging in simultaneous PET-MR. The proposed methods were evaluated in a realistic four-dimensional PET-MR simulation study obtained by combining patient water-fat separated MRI and XCAT anthropomorphic phantom. Five small lesions were digitally inserted inside the patients coronary vessels to mimic coronary atherosclerotic plaques. The heart of the XCAT phantom was digitally replaced with the patient's heart. Motion-dependent activity distributions, attenuation maps, and fat-MR volumes of the heart, were generated using the XCAT cardiac and respiratory motion fields. A full Monte Carlo simulation using Siemens mMR's geometry was performed for each motion phase. Cardiac/respiratory motion fields were estimated using non-rigid registration of the transformed fat-MR volumes and incorporated directly into the system matrix of PET reconstruction along with motion-dependent attenuation maps. The proposed motion correction method was compared to conventional PET reconstruction techniques such as no motion correction, cardiac gating, and dual cardiac-respiratory gating. Compared to uncorrected reconstructions, fat-MR based motion compensation yielded an average improvement of plaque-to-background contrast of 29.6%, 43.7%, 57.2%, and 70.6% for true plaque-to-blood ratios of 10, 15, 20 and 25:1, respectively. Channelized Hotelling observer (CHO) signal-to-noise ratio (SNR) was used to quantify plaque detectability. CHO-SNR improvement ranged from 105% to 128% for fat-MR-based motion correction as compared to no motion correction. Likewise, CHO-SNR improvement ranged from 348% to 396% as compared to both cardiac and dual cardiac-respiratory gating approaches. Based on this study, our approach, a fat-MR based motion correction for coronary plaque PET imaging using simultaneous PET-MR, offers great potential for clinical practice. The ultimate performance and limitation of our approach, however, must be fully evaluated in patient studies.
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