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Johnson SP, Ogunlade O, Lythgoe MF, Beard P, Pedley RB. Longitudinal Photoacoustic Imaging of the Pharmacodynamic Effect of Vascular Targeted Therapy on Tumors. Clin Cancer Res 2019; 25:7436-7447. [PMID: 31551349 PMCID: PMC7611302 DOI: 10.1158/1078-0432.ccr-19-0360] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2019] [Revised: 07/29/2019] [Accepted: 09/19/2019] [Indexed: 11/16/2022]
Abstract
PURPOSE Photoacoustic imaging (PAI) is a novel noninvasive and nonionizing imaging technique that allows longitudinal imaging of tumor vasculature in vivo and monitoring of response to therapy, especially for vascular targeted chemotherapy agents. In this study, we used a novel high-resolution all-optical PAI scanner to observe the pharmacodynamic response to the vascular-disrupting agent OXi4503. EXPERIMENTAL DESIGN Two models of colorectal carcinoma (SW1222 and LS174T) that possess differing pathophysiologic vascularization were established as subcutaneous tumors in mice. Monitoring of response was performed over a 16-day "regrowth" period following treatment at 40 mg/kg, and at day 2 for a "dose response" study at 40 mg/kg, 10 mg/kg, 1 mg/kg, and sham dose. RESULTS Qualitative and quantitative changes in PA signal are observed, with an initial decrease followed by a plateau and subsequent return of signal indicating regrowth. Both tumor types exhibited a decrease in signal; however, the more vascularized SW1222 tumors show greater response to treatment. Decreasing the dose of OXi4503 led to a decrease in PA signal intensity of 60%, 52%, and 20% in SW1222 tumors and 30%, 26%, and 4% for LS174T tumors. CONCLUSIONS We have shown for the first time that PAI can observe the pharmacodynamic response of tumor vasculature to drug treatment both longitudinally and at different dose levels. Assessment of differing response to treatment based on vascular pathophysiologic differences among patients has the potential to provide personalized drug therapy; we have demonstrated that PAI, which is clinically translatable, could be a powerful tool for this purpose.
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Affiliation(s)
- S Peter Johnson
- UCL Cancer Institute, University College London, London, United Kingdom.
| | - Olumide Ogunlade
- UCL Department of Medical Physics and Biomedical Engineering, University College London, London, United Kingdom
| | - Mark F Lythgoe
- UCL Centre for Advanced Biomedical Imaging, Division of Medicine, University College London, London, United Kingdom
| | - Paul Beard
- UCL Department of Medical Physics and Biomedical Engineering, University College London, London, United Kingdom
| | - R Barbara Pedley
- UCL Cancer Institute, University College London, London, United Kingdom
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Gonçalves MR, Peter Johnson S, Ramasawmy R, Barbara Pedley R, Lythgoe MF, Walker-Samuel S. Decomposition of spontaneous fluctuations in tumour oxygenation using BOLD MRI and independent component analysis. Br J Cancer 2016; 114:e13. [PMID: 27228297 PMCID: PMC4984470 DOI: 10.1038/bjc.2016.140] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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Ramasawmy R, Johnson SP, Roberts TA, Stuckey DJ, David AL, Pedley RB, Lythgoe MF, Siow B, Walker-Samuel S. Monitoring the Growth of an Orthotopic Tumour Xenograft Model: Multi-Modal Imaging Assessment with Benchtop MRI (1T), High-Field MRI (9.4T), Ultrasound and Bioluminescence. PLoS One 2016; 11:e0156162. [PMID: 27223614 PMCID: PMC4880291 DOI: 10.1371/journal.pone.0156162] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2015] [Accepted: 05/10/2016] [Indexed: 12/25/2022] Open
Abstract
BACKGROUND Research using orthotopic and transgenic models of cancer requires imaging methods to non-invasively quantify tumour burden. As the choice of appropriate imaging modality is wide-ranging, this study aimed to compare low-field (1T) magnetic resonance imaging (MRI), a novel and relatively low-cost system, against established preclinical techniques: bioluminescence imaging (BLI), ultrasound imaging (US), and high-field (9.4T) MRI. METHODS A model of colorectal metastasis to the liver was established in eight mice, which were imaged with each modality over four weeks post-implantation. Tumour burden was assessed from manually segmented regions. RESULTS All four imaging systems provided sufficient contrast to detect tumours in all of the mice after two weeks. No significant difference was detected between tumour doubling times estimated by low-field MRI, ultrasound imaging or high-field MRI. A strong correlation was measured between high-field MRI estimates of tumour burden and all the other modalities (p < 0.001, Pearson). CONCLUSION These results suggest that both low-field MRI and ultrasound imaging are accurate modalities for characterising the growth of preclinical tumour models.
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Affiliation(s)
- Rajiv Ramasawmy
- UCL Centre for Advanced Biomedical Imaging, Division of Medicine, London, United Kingdom
- UCL Cancer Institute, London, United Kingdom
| | - S. Peter Johnson
- UCL Centre for Advanced Biomedical Imaging, Division of Medicine, London, United Kingdom
- UCL Cancer Institute, London, United Kingdom
| | - Thomas A. Roberts
- UCL Centre for Advanced Biomedical Imaging, Division of Medicine, London, United Kingdom
| | - Daniel J. Stuckey
- UCL Centre for Advanced Biomedical Imaging, Division of Medicine, London, United Kingdom
| | - Anna L. David
- UCL Institute for Women’s Health, London, United Kingdom
| | | | - Mark F. Lythgoe
- UCL Centre for Advanced Biomedical Imaging, Division of Medicine, London, United Kingdom
| | - Bernard Siow
- UCL Centre for Advanced Biomedical Imaging, Division of Medicine, London, United Kingdom
| | - Simon Walker-Samuel
- UCL Centre for Advanced Biomedical Imaging, Division of Medicine, London, United Kingdom
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Johnson SP, Ramasawmy R, Campbell-Washburn AE, Wells JA, Robson M, Rajkumar V, Lythgoe MF, Pedley RB, Walker-Samuel S. Acute changes in liver tumour perfusion measured non-invasively with arterial spin labelling. Br J Cancer 2016; 114:897-904. [PMID: 27031853 PMCID: PMC4984798 DOI: 10.1038/bjc.2016.51] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Revised: 01/26/2016] [Accepted: 02/04/2016] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND Non-invasive measures of tumour vascular perfusion are desirable, in order to assess response to vascular targeting (or modifying) therapies. In this study, hepatic arterial spin labelling (ASL) magnetic resonance imaging (MRI) was investigated to measure acute changes in perfusion of colorectal cancer in the liver, in response to vascular disruption therapy with OXi4503. METHODS SW1222 and LS174T tumours were established in the liver of MF1 nu/nu mice via intrasplenic injection. Perfusion and R2(*) MRI measurements were acquired with an Agilent 9.4T horizontal bore scanner, before and at 90 min after 40 mg kg(-1) OXi4503. RESULTS A significant decrease in SW1222 tumour perfusion was observed (-43±33%, P<0.005). LS174T tumours had a significantly lower baseline level of perfusion. Intrinsic susceptibility MRI showed a significant increase in R2(*) in LS174T tumours (28±25%, P<0.05). An association was found between the change in tumour perfusion and the proximity to large vessels, with pre-treatment blood flow predictive of subsequent response. Histological evaluation confirmed the onset of necrosis and evidence of heterogeneous response between tumour deposits. CONCLUSIONS Hepatic ASL-MRI can detect acute response to targeted tumour vascular disruption entirely non-invasively. Hepatic ASL of liver tumours has potential for use in a clinical setting.
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Affiliation(s)
- S Peter Johnson
- UCL Cancer Institute, University College London, Paul O'Gorman Building, 72 Huntley Street, London WC1E 6DD, UK
- UCL Centre for Advanced Biomedical Imaging, University College London, Paul O'Gorman Building, 72 Huntley Street, London WC1E 6DD, UK
| | - Rajiv Ramasawmy
- UCL Cancer Institute, University College London, Paul O'Gorman Building, 72 Huntley Street, London WC1E 6DD, UK
- UCL Centre for Advanced Biomedical Imaging, University College London, Paul O'Gorman Building, 72 Huntley Street, London WC1E 6DD, UK
| | - Adrienne E Campbell-Washburn
- UCL Centre for Advanced Biomedical Imaging, University College London, Paul O'Gorman Building, 72 Huntley Street, London WC1E 6DD, UK
- Cardiovascular and Pulmonary Branch, Division of Intramural Research, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Jack A Wells
- UCL Centre for Advanced Biomedical Imaging, University College London, Paul O'Gorman Building, 72 Huntley Street, London WC1E 6DD, UK
| | - Mathew Robson
- UCL Cancer Institute, University College London, Paul O'Gorman Building, 72 Huntley Street, London WC1E 6DD, UK
| | - Vineeth Rajkumar
- UCL Cancer Institute, University College London, Paul O'Gorman Building, 72 Huntley Street, London WC1E 6DD, UK
| | - Mark F Lythgoe
- UCL Centre for Advanced Biomedical Imaging, University College London, Paul O'Gorman Building, 72 Huntley Street, London WC1E 6DD, UK
| | - R Barbara Pedley
- UCL Cancer Institute, University College London, Paul O'Gorman Building, 72 Huntley Street, London WC1E 6DD, UK
| | - Simon Walker-Samuel
- UCL Centre for Advanced Biomedical Imaging, University College London, Paul O'Gorman Building, 72 Huntley Street, London WC1E 6DD, UK
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Gonçalves MR, Johnson SP, Ramasawmy R, Pedley RB, Lythgoe MF, Walker-Samuel S. Decomposition of spontaneous fluctuations in tumour oxygenation using BOLD MRI and independent component analysis. Br J Cancer 2015; 113:1168-77. [PMID: 26484634 PMCID: PMC4647875 DOI: 10.1038/bjc.2015.270] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Revised: 05/26/2015] [Accepted: 06/29/2015] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND Solid tumours can undergo cycles of hypoxia, followed by reoxygenation, which can have significant implications for the success of anticancer therapies. A need therefore exists to develop methods to aid its detection and to further characterise its biological basis. We present here a novel method for decomposing systemic and tumour-specific contributions to fluctuations in tumour deoxyhaemoglobin concentration, based on magnetic resonance imaging measurements. METHODS Fluctuations in deoxyhaemoglobin concentration in two tumour xenograft models of colorectal carcinoma were decomposed into distinct contributions using independent component analysis. These components were then correlated with systemic pulse oximetry measurements to assess the influence of systemic variations in blood oxygenation in tumours, compared with those that arise within the tumour itself (tumour-specific). Immunohistochemical staining was used to assess the physiological basis of each source of fluctuation. RESULTS Systemic fluctuations in blood oxygenation were found to contribute to cycling hypoxia in tumours, but tumour-specific fluctuations were also evident. Moreover, the size of the tumours was found to influence the degree of systemic, but not tumour-specific, oscillations. The degree of vessel maturation was related to the amplitude of tumour-specific, but not systemic, oscillations. CONCLUSIONS Our results provide further insights into the complexity of spontaneous fluctuations in tumour oxygenation and its relationship with tumour pathophysiology. These observations could be used to develop improved drug delivery strategies.
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Affiliation(s)
- Miguel R Gonçalves
- Centre for Advanced Biomedical Imaging, Division of Medicine, University College London, London WC1E 6DD, UK
| | - S Peter Johnson
- Centre for Advanced Biomedical Imaging, Division of Medicine, University College London, London WC1E 6DD, UK
- Cancer Institute, University College London, London WC1E 6DD, UK
| | - Rajiv Ramasawmy
- Centre for Advanced Biomedical Imaging, Division of Medicine, University College London, London WC1E 6DD, UK
| | - R Barbara Pedley
- Cancer Institute, University College London, London WC1E 6DD, UK
| | - Mark F Lythgoe
- Centre for Advanced Biomedical Imaging, Division of Medicine, University College London, London WC1E 6DD, UK
| | - Simon Walker-Samuel
- Centre for Advanced Biomedical Imaging, Division of Medicine, University College London, London WC1E 6DD, UK
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Ramasawmy R, Campbell-Washburn AE, Wells JA, Johnson SP, Pedley RB, Walker-Samuel S, Lythgoe MF. Hepatic arterial spin labelling MRI: an initial evaluation in mice. NMR Biomed 2015; 28:272-80. [PMID: 25522098 PMCID: PMC4670473 DOI: 10.1002/nbm.3251] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2014] [Revised: 10/09/2014] [Accepted: 11/26/2014] [Indexed: 05/20/2023]
Abstract
The development of strategies to combat hepatic disease and augment tissue regeneration has created a need for methods to assess regional liver function. Liver perfusion imaging has the potential to fulfil this need, across a range of hepatic diseases, alongside the assessment of therapeutic response. In this study, the feasibility of hepatic arterial spin labelling (HASL) was assessed for the first time in mice at 9.4 T, its variability and repeatability were evaluated, and it was applied to a model of colorectal liver metastasis. Data were acquired using flow-sensitive alternating inversion recovery-arterial spin labelling (FAIR-ASL) with a Look-Locker readout, and analysed using retrospective respiratory gating and a T1 -based quantification. This study shows that preclinical HASL is feasible and exhibits good repeatability and reproducibility. Mean estimated liver perfusion was 2.2 ± 0.8 mL/g/min (mean ± standard error, n = 10), which agrees well with previous measurements using invasive approaches. Estimates of the variation gave a within-session coefficient of variation (CVWS) of 7%, a between-session coefficient of variation (CVBS) of 9% and a between-animal coefficient of variation (CVA) of 15%. The within-session Bland-Altman repeatability coefficient (RCWS) was 18% and the between-session repeatability coefficient (RCBS) was 29%. Finally, the HASL method was applied to a mouse model of liver metastasis, in which significantly lower mean perfusion (1.1 ± 0.5 mL/g/min, n = 6) was measured within the tumours, as seen by fluorescence histology. These data indicate that precise and accurate liver perfusion estimates can be achieved using ASL techniques, and provide a platform for future studies investigating hepatic perfusion in mouse models of disease.
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Affiliation(s)
- R Ramasawmy
- UCL Centre for Advanced Biomedical ImagingPaul O'Gorman Building, London, UK
- UCL Cancer InstitutePaul O'Gorman Building, London, UK
| | | | - J A Wells
- UCL Centre for Advanced Biomedical ImagingPaul O'Gorman Building, London, UK
| | - S P Johnson
- UCL Centre for Advanced Biomedical ImagingPaul O'Gorman Building, London, UK
- UCL Cancer InstitutePaul O'Gorman Building, London, UK
| | - R B Pedley
- UCL Cancer InstitutePaul O'Gorman Building, London, UK
| | - S Walker-Samuel
- UCL Centre for Advanced Biomedical ImagingPaul O'Gorman Building, London, UK
| | - M F Lythgoe
- UCL Centre for Advanced Biomedical ImagingPaul O'Gorman Building, London, UK
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Panagiotaki E, Walker-Samuel S, Siow B, Johnson SP, Rajkumar V, Pedley RB, Lythgoe MF, Alexander DC. Noninvasive quantification of solid tumor microstructure using VERDICT MRI. Cancer Res 2014; 74:1902-12. [PMID: 24491802 DOI: 10.1158/0008-5472.can-13-2511] [Citation(s) in RCA: 143] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
There is a need for biomarkers that are useful for noninvasive imaging of tumor pathophysiology and drug efficacy. Through its use of endogenous water, diffusion-weighted MRI (DW-MRI) can be used to probe local tissue architecture and structure. However, most DW-MRI studies of cancer tissues have relied on simplistic mathematical models, such as apparent diffusion coefficient (ADC) or intravoxel incoherent motion (IVIM) models, which produce equivocal results on the relation of the model parameter estimate with the underlying tissue microstructure. Here, we present a novel technique called VERDICT (Vascular, Extracellular and Restricted Diffusion for Cytometry in Tumors) to quantify and map histologic features of tumors in vivo. VERDICT couples DW-MRI to a mathematical model of tumor tissue to access features such as cell size, vascular volume fraction, intra- and extracellular volume fractions, and pseudo-diffusivity associated with blood flow. To illustrate VERDICT, we used two tumor xenograft models of colorectal cancer with different cellular and vascular phenotypes. Our experiments visualized known differences in the tissue microstructure of each model and the significant decrease in cell volume resulting from administration of the cytotoxic drug gemcitabine, reflecting the apoptotic volume decrease. In contrast, the standard ADC and IVIM models failed to detect either of these differences. Our results illustrate the superior features of VERDICT for cancer imaging, establishing it as a noninvasive method to monitor and stratify treatment responses.
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Affiliation(s)
- Eletheria Panagiotaki
- Authors' Affiliations: Department of Computer Science, Centre for Medical Image Computing; Division of Medicine, Centre for Advanced Biomedical Imaging; UCL Cancer Institute, University College London, London, United Kingdom
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Abstract
In order to evaluate the following potential mechanisms underlying atypical gaze following in autism, impaired reflexive gaze following, difficulty integrating gaze and affect, or reduced understanding of the referential significance of gaze, we administered three paradigms to young children with autism (N = 21) and chronological (N = 21) and nonverbal mental age (N = 21) matched controls. Children with autism exhibited impaired reflexive gaze following. The absence of evidence of integration of gaze and affect, regardless of diagnosis, indicates ineffective measurement of this construct. Reduced gaze following was apparent among children with autism during eye-tracking and in-person assessments. Word learning from gaze cues was better explained by developmental level than autism. Thus, gaze following may traverse an atypical, rather than just delayed, trajectory in autism.
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Affiliation(s)
- K Gillespie-Lynch
- Department of Psychology, College of Staten Island, City University of New York, Staten Island, NY, USA,
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Walker-Samuel S, Ramasawmy R, Torrealdea F, Rega M, Rajkumar V, Johnson SP, Richardson S, Gonçalves M, Parkes HG, Arstad E, Thomas DL, Pedley RB, Lythgoe MF, Golay X. In vivo imaging of glucose uptake and metabolism in tumors. Nat Med 2013; 19:1067-72. [PMID: 23832090 PMCID: PMC5275770 DOI: 10.1038/nm.3252] [Citation(s) in RCA: 364] [Impact Index Per Article: 33.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2012] [Accepted: 10/26/2012] [Indexed: 01/01/2023]
Abstract
Tumors have a greater reliance on anaerobic glycolysis for energy production than normal tissues. We developed a noninvasive method for imaging glucose uptake in vivo that is based on magnetic resonance imaging and allows the uptake of unlabeled glucose to be measured through the chemical exchange of protons between hydroxyl groups and water. This method differs from existing molecular imaging methods because it permits detection of the delivery and uptake of a metabolically active compound in physiological quantities. We show that our technique, named glucose chemical exchange saturation transfer (glucoCEST), is sensitive to tumor glucose accumulation in colorectal tumor models and can distinguish tumor types with differing metabolic characteristics and pathophysiologies. The results of this study suggest that glucoCEST has potential as a useful and cost-effective method for characterizing disease and assessing response to therapy in the clinic.
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Affiliation(s)
- Simon Walker-Samuel
- University College London Centre for Advanced Biomedical Imaging, Division of Medicine and Institute of Child Health, London, UK.
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Walker-Samuel S, Johnson SP, Pedley B, Lythgoe MF, Golay X. Extracranial measurements of amide proton transfer using exchange-modulated point-resolved spectroscopy (EXPRESS). NMR Biomed 2012; 25:829-834. [PMID: 22135248 DOI: 10.1002/nbm.1798] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2011] [Revised: 09/03/2011] [Accepted: 09/12/2011] [Indexed: 05/31/2023]
Abstract
Chemical exchange saturation transfer (CEST) imaging has been used experimentally in a large range of applications. However, full quantification of CEST effects in vivo using standard imaging sequences is time consuming as a large number of saturation frequency offsets, each followed by an imaging readout, are required to define a z spectrum. Furthermore, outside the brain, the presence of fat can confound the interpretation of z spectra. A novel acquisition and post-processing technique is presented in this study, named exchange-modulated point-resolved spectroscopy (EXPRESS), which aims to address these limitations and to enable spatially localised, high signal-to-noise measurements of CEST effects in vivo. Using amide proton exchange (APT) measurements in tumours, it is demonstrated that the acquisition of two-dimensional EXPRESS spectra composed of chemical shift and saturation frequency offset dimensions allows the correction of CEST data containing both fat and water signals, which is a common confounding property of tissues found outside the brain.
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Affiliation(s)
- Simon Walker-Samuel
- UCL Centre for Advanced Biomedical Imaging, Department of Medicine and Institute of Child Health, University College London, London, UK.
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Abstract
AIMS To evaluate the association between vitamin D insufficiency and peripheral neuropathy in a nationally representative sample of adults with diagnosed diabetes. METHODS Vitamin D concentrations, medical examination variables and questionnaire results from the 2001-2004 National Health and Nutrition Examination Survey were analysed for adults ≥ 40 years old with diagnosed diabetes (unweighted n = 591, weighted n = 8.82 million). Neuropathy was defined as self report of peripheral neuropathy symptoms of painful sensation, tingling, numbness or loss of feeling in hands or feet. Additionally, Semmes-Weinstein monofilament test results were used as an indicator of neuropathy. Insufficient vitamin D was characterized as < 30 ng/ml. RESULTS In the weighted population, 81% of adults with diabetes had vitamin D insufficiency. Vitamin D insufficiency was more common among Hispanics (92%) and non-Hispanic black people (98%) than among non-Hispanic white people (76%). Within the 3 months preceding the questionnaire, 50% reported experiencing pain or numbness (paresthesia) in their hands or feet; 37% reported pain or tingling in hands or feet; and 38% reported numbness or loss of feeling in hands or feet. Eight per cent had 4-6 insensate areas on their feet as determined by the Semmes-Weinstein monofilament test. Logistic regressions demonstrate vitamin D insufficiency is associated with the adjusted composite paresthesia measure (odds ratio 2.12; 95% CI 1.17-3.85) and the adjusted numbness measure (odds ratio 2.04; 95% CI 1.18-3.52). CONCLUSIONS Vitamin D insufficiency is associated with self-reported peripheral neuropathy symptoms even after adjusting for demographic factors, obesity, co-morbidities, use of medications for neuropathy and diabetes duration and control.
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Affiliation(s)
- L H Soderstrom
- Department of Medicine, Division of Biostatistics and Epidemiology, Medical University of South Carolina, Charleston, SC 29425, USA
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Johnson SP, Welsh TM, Miller LK, Altus DE. Participatory management: Maintaining staff performance in a university housing cooperative. J Appl Behav Anal 2010; 24:119-27. [PMID: 16795739 PMCID: PMC1279553 DOI: 10.1901/jaba.1991.24-119] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
To apply behavior analysis to normal adults in non institutional settings, we may have to encourage their participation in the design and implementation of behavioral technology. This study evaluates a technology by which the members of a student housing cooperative manage their own staff with a minimum of supervision by one of the program designers. This staff management system consisted of prompts, self-reports, spot checks, and contingent rent reductions. Six resident staff members performed substantially more of their assigned tasks when this system was used. In addition, the management system was acceptable to the members, was affordable, and maintained high levels of staff performance during a 5-year follow-up. Participation by the members in the design and implementation of this system appears to have been useful in helping the behavior analysts to develop an unusually durable management system.
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Cui B, Johnson SP, Bullock N, Ali-Osman F, Bigner DD, Friedman HS. Bifunctional DNA alkylator 1,3-bis(2-chloroethyl)-1-nitrosourea activates the ATR-Chk1 pathway independently of the mismatch repair pathway. Mol Pharmacol 2009; 75:1356-63. [PMID: 19261750 DOI: 10.1124/mol.108.053124] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
The presence of DNA damage initiates signaling through the ataxia-telangiectasia mutated kinase (ATM) and the ATM- and the Rad3-related kinase (ATR), which phosphorylate, thus activating, the checkpoint kinases (Chk) 1 and 2, which leads to cell cycle arrest. The bifunctional DNA alkylator 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU) is cytotoxic primarily by inducing DNA monoadducts and ultimately, interstrand cross-links, which block DNA replication. In this study, we investigated the activation of the ATR-Chk1 pathway in response to BCNU treatment and the dependence of this response on the DNA mismatch repair (MMR) capacity. Medulloblastoma cells were exposed to low and moderate doses of BCNU, and the effects on this DNA damage signaling pathway were examined. In response to BCNU, Chk1 was found to be phosphorylated at serine 345 and exhibited increased kinase activity. Caffeine and wortmannin, which are broad-spectrum inhibitors of ATM and ATR, reduced this phosphorylation. Cell cycle analysis further revealed an accumulation of cells in the S phase in response to BCNU, an effect that was attenuated by caffeine. Small interfering RNA knockdown of ATR also reduced Chk1 phosphorylation after exposure to BCNU. However, knockdown of ATM had no effect on the observed Chk1 phosphorylation, suggesting that ATR was primarily responsible for Chk1 activation. Analysis of Chk1 activation in cells deficient in MMR proteins MutLalpha or MutSalpha indicated that the DNA damage response induced by BCNU was independent of the MMR apparatus. This MMR-independent activation seems to be the result of DNA interstrand cross-link formation.
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Affiliation(s)
- B Cui
- Departments of Surgery, Duke University Medical Center, Durham, NC 27710, USA
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Castellino RC, Elion GB, Keir ST, Houghton PJ, Johnson SP, Bigner DD, Friedman HS. Schedule-dependent activity of irinotecan plus BCNU against malignant glioma xenografts. Cancer Chemother Pharmacol 2001; 45:345-9. [PMID: 10755324 DOI: 10.1007/s002800050050] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
PURPOSE To further evaluate the activity of irinotecan (CPT-11) plus 1,3-bis-(chloroethyl)-1-nitrosourea (BCNU) in the treatment of central nervous system tumor-derived xenografts in athymic nude mice. METHODS We report studies evaluating the schedule-dependence of this regimen in the treatment of the malignant glioma xenograft D-54 MG. RESULTS The combination of BCNU and CPT-11 showed the highest enhancement index (2.0-3.3) when BCNU was given on day 1 and CPT-11 was given on days 1-5 and 8-12. Delay of CPT-11 administration to day 3 or day 5 substantially decreased activity with enhancement indices of 1.6-1.8 and 0.6-1.0, respectively. Delay of BCNU administration to day 8 also reduced the CPT-11 activity with enhancement indices of 1.2-1.4. CONCLUSIONS These results suggest that the presence of a BCNU-induced adduct or possibly crosslink prior to administration of CPT-11 is critical for enhanced activity. Although the mechanism of this enhancement is not currently known, a phase I trial of CPT-11 plus BCNU for adults with recurrent malignant glioma based on these results is in progress.
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Affiliation(s)
- R C Castellino
- Department of Surgery, Duke University Medical Center, Durham, NC 27710, USA
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Johnson SP, Aslin RN. Infants' perception of transparency. Dev Psychol 2000; 36:808-16. [PMID: 11081703] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/18/2023]
Abstract
Four- and 7-month-old infants' perception of transparency was investigated with computer-generated achromatic or color displays depicting a semitransparent box occluding the center of a rod. Following habituation, infants viewed test displays consisting of either a two-color rod (corresponding to the habituation display's proximal characteristics) or a solid rod (corresponding to the distal characteristics of the event depicted by the habituation display). Looking-time results from 4-month-olds suggested perception of transparency in color displays but not in an achromatic display. An additional condition indicated that transparency perception may rely on the visibility of background texture through the transparent surface. Seven-month-olds, in contrast, provided some evidence of transparency perception in the achromatic display. Implications for the development of infants' responses to object properties and perceptual segregation are discussed.
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Affiliation(s)
- S P Johnson
- Department of Psychology, Cornell University, Ithaca, New York 14853, USA.
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Vaidyanathan G, Affleck DJ, Cavazos CM, Johnson SP, Shankar S, Friedman HS, Colvin MO, Zalutsky MR. Radiolabeled guanine derivatives for the in vivo mapping of O(6)-alkylguanine-DNA alkyltransferase: 6-(4-[(18)F]Fluoro-benzyloxy)-9H-purin-2-ylamine and 6-(3-[(131)I]Iodo-benzyloxy)-9H-purin-2-ylamine. Bioconjug Chem 2000; 11:868-75. [PMID: 11087336 DOI: 10.1021/bc0000435] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Two radiolabeled analogues of 6-benzyloxy-9H-purin-2-ylamine (O(6)-benzylguanine; BG) potentially useful in the in vivo mapping of O(6)-alkylguanine-DNA alkyltransferase (AGT) were synthesized. Fluorine-18 labeling of the known 6-(4-fluoro-benzyloxy)-9H-purin-2-ylamine (FBG; 6) was accomplished by the condensation of 4-[(18)F]fluorobenzyl alcohol with 2-aminopurin-6-yltrimethylammonium chloride (4) or 2-amino-6-chloropurine in average decay-corrected radiochemical yields of 40 and 25%, respectively. Unlabeled 6-(3-iodo-benzyloxy)-9H-purin-2-ylamine (IBG; 7) was prepared from 4 and 3-iodobenzyl alcohol. Radioiodination of 9, prepared from 7 in two steps, and subsequent deprotection gave [(131)I]7 in about 70% overall radiochemical yield. The IC(50) values for the inactivation of AGT from CHO cells transfected with pCMV-AGT were 15 nM for IBG and 50 nM for FBG. The binding of [(18)F]6 and [(131)I]7 to purified AGT was specific and saturable with both exhibiting similar IC(50) values (5-6 microM).
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Affiliation(s)
- G Vaidyanathan
- Departments of Radiology, Pediatrics, Surgery and Medicine, and School of Medicine, Duke University Medical Center, Durham, North Carolina 27710, USA.
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Patel VJ, Elion GB, Houghton PJ, Keir S, Pegg AE, Johnson SP, Dolan ME, Bigner DD, Friedman HS. Schedule-dependent activity of temozolomide plus CPT-11 against a human central nervous system tumor-derived xenograft. Clin Cancer Res 2000; 6:4154-7. [PMID: 11051270] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/18/2023]
Abstract
Temozolomide, an imidazole tetrazinone, and CPT-11, a camptothecin derivative, have previously been shown to have anti-central nervous system tumor activity in laboratory and clinical studies. The current experiments were designed to evaluate the activity of temozolomide plus CPT-11 against a malignant glioma-derived xenograft, D-54 MG, growing s.c. in athymic nude mice. The initial schedule of i.p. drug administration was temozolomide at 0.1 LD10 on day 1 and CPT-11 at 0.1 LD10 on days 1-5 and 8-14. The combination of these two agents produced greater than additive activity against D-54 MG. This enhanced activity was maintained when the initial administration of CPT-11 was delayed to day 3 or day 5. However, when CPT-11 was administered first on day 1 using 0.5 LD10 (for the single dose schedule) followed by temozolomide (0.1 LD10) 5 h, 3 days, or 5 days later, the enhancement of activity was substantially reduced. These results demonstrate that the combination of temozolomide plus CPT-11 displays a schedule-dependent enhancement of antitumor activity, suggest a mechanistic explanation for the enhanced activity, and provide the rationale for a Phase I trial of this regimen.
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Affiliation(s)
- V J Patel
- Department of Surgery, Pathology [Duke University Medical Center, Durham, North Carolina 27710, USA
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Gulland FM, Stoskopf MK, Johnson SP, Riviere J, Papich MG. Amoxicillin pharmacokinetics in harbor seals (Phoca vitulina) and northern elephant seals (Mirounga angustirostris) following single dose intravenous administration: implications for interspecific dose scaling. J Vet Pharmacol Ther 2000; 23:223-8. [PMID: 11126323 DOI: 10.1046/j.1365-2885.2000.00263.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The pharmacokinetics of sodium amoxicillin after a single intravenous dose of 20 mg/kg were determined in ten harbor seals (Phoca vitulina) and ten northern elephant seals (Mirounga angustirostris). The seals ranged in age from 1 to 6 months and the mean weights were 11.7 kg (range, 9.5-18.5 kg) for harbor seals and 47.1 kg (range, 39.5-61.4 kg) for elephant seals. The median half-life of amoxicillin (quartiles) in harbor seals, 1.5 (1.0-3.1) h. was not statistically different from that of elephant seals, 2.0 (1.4-3.8) h, nor were the differences between the terminal elimination rate constants between the two species. The only statistically significant differences between species were for area-under-the-curve (AUC), and total systemic clearance. The lack of statistical significance for differences in the volume of distribution at steady-state (Vss) may have been due to minor differences in the time frame of data collection and dose administered between the two groups. A true physiologic difference in drug handling, possibly related to renal perfusion or tubal secretory efficiency could affect amoxicillin kinetics in these species, and longer administration intervals may be appropriate for elephant seals as compared to harbor seals when administering multiple dose amoxicillin therapy at 20 mg/kg.
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Affiliation(s)
- F M Gulland
- The Marine Mammal Center, Marin Headlands, GGNRA, Sausalito, CA 94965, USA
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19
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Abstract
Young infants have been reported to perceive the unity of a center-occluded object when the visible ends of the object undergo common motion, but not on the basis of stationary information (e.g., P. J. Kellman & E. S. Spelke, 1983). We investigated the possibility that 4-month-old infants will attend to and utilize the global configuration (i.e., the "good form") of a partly occluded, moving object to perceive its unity and coherence behind the occluder. In the first experiment, infants viewed a partly occluded circle or cross that translated laterally. Infants who habituated in the minimum number of trials ("fast habituators") showed a reliable posthabituation preference for a broken object over a complete object, indicating perception of unity in the habituation display. Slow habituators exhibited no posthabituation preference. In the second experiment, infants were presented with small ring and cross displays, and the infants looked longer at the broken object. There were no reliable differences in performance between fast and slow habituators. A control group demonstrated no reliable posthabituation preference. In three additional conditions, infants viewed either a partly occluded half ring or a display in which two rod parts were either relatable and nonaligned or nonrelatable. The results indicated that curvature per se provided information in support of completion, in addition to global configuration and motion. Implications for theories of infants' visual development are discussed.
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Affiliation(s)
- S P Johnson
- Department of Psychology, Cornell University, Ithaca, NY 14853, USA.
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20
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Abstract
Adults and infants display a robust ability to perceive the unity of a center-occluded object when the visible ends of the object undergo common motion (e.g. Kellman, P.J., Spelke, E.S., 1983. Perception of partly occluded objects in infancy. Cognitive Psychology 15, 483-524). Ecologically oriented accounts of this ability focus on the primary of motion in the perception of segregated objects, but Gestalt theory suggests a broader possibility: observers may perceive object unity by detecting patterns of synchronous change, of which common motion is a special case. We investigated this possibility with observations of adults and 4-month-old infants. Participants viewed a center-occluded object whose visible surfaces were either misaligned or aligned, stationary or moving, and unchanging or synchronously changing in color or brightness in various temporal patterns (e.g. flashing). Both alignment and common motion contributed to adults' perception of object unity, but synchronous color changes did not. For infants, motion was an important determinant of object unity, but other synchronous changes and edge alignment were not. When a stationary object with aligned edges underwent synchronous changes in color or brightness, infants showed high levels of attention to the object, but their perception of its unity appeared to be indeterminate. An inherent preference for fast over slow flash rates, and a novelty preference elicited by a change in rate, both indicated that infants detected the synchronous changes, although they failed to use them as information for object unity. These findings favor ecologically oriented accounts of object perception in which surface motion plays a privileged role.
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Affiliation(s)
- P W Jusczyk
- Department of Psychology, Johns Hopkins University, Baltimore, MD 21218-2685, USA.
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Johnson SP, Durham JD, Subber SW, Gordon M, Rutherford R, Law C, Krysl J, Kumpe DA. Acute arterial occlusions of the small vessels of the hand and forearm: treatment with regional urokinase therapy. J Vasc Interv Radiol 1999; 10:869-76. [PMID: 10435703 DOI: 10.1016/s1051-0443(99)70130-2] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
PURPOSE Arterial occlusions of the small vessels of the forearm and hand may have the same consequences as arterial occlusions in the distal lower extremity. There is limited reported experience with the regional thrombolytic therapy in this setting. The authors reviewed their experience with thrombolytic therapy in acute and subacute arterial occlusions of the distal upper extremity to further clarify its role. MATERIALS AND METHODS Twelve patients with acute or subacute arterial occlusions of the forearm and hand who had ischemic digits and were treated with regional urokinase infusion were identified retrospectively. Their medical and radiology records were reviewed. RESULTS All 12 patients demonstrated angiographic improvement and 11 patients demonstrated clinical improvement after treatment. Tissue necrosis in four patients led to partial amputation of one digit in two patients and three digits in two patients. Three of these patients had category III ischemia at presentation. The level of resulting amputation was altered in all but one patient. Vasospasm was noted frequently but responded to vasodilators. No significant complications occurred. CONCLUSIONS When therapeutic alternatives are limited to anticoagulation and expectant amputation, regional urokinase infusion can optimize distal runoff, obviate or improve the options for distal surgical bypass, and limit tissue loss.
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Affiliation(s)
- S P Johnson
- Department of Radiology, University of Colorado Health Sciences Center, Denver 80262, USA
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Friedman HS, Pegg AE, Johnson SP, Loktionova NA, Dolan ME, Modrich P, Moschel RC, Struck R, Brent TP, Ludeman S, Bullock N, Kilborn C, Keir S, Dong Q, Bigner DD, Colvin OM. Modulation of cyclophosphamide activity by O6-alkylguanine-DNA alkyltransferase. Cancer Chemother Pharmacol 1999; 43:80-5. [PMID: 9923545 DOI: 10.1007/s002800050866] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
PURPOSE The human medulloblastoma cell line D283 Med (4-HCR), a line resistant to 4-hydroperoxycyclophosphamide (4-HC), displays enhanced repair of DNA interstrand crosslinks induced by phosphoramide mustard. D283 Med (4-HCR) cells are cross-resistant to 1,3-bis(2-chloroethyl)- -nitrosourea, but partial sensitivity is restored after elevated levels of O6-alkylguanine-DNA alkyltransferase (AGT) are depleted by O6-benzylguanine (O6-BG). Studies were conducted to define the activity of 4-HC and 4-hydroperoxydidechlorocyclophosphamide against D283 Med (4-HCR) after AGT is depleted by O6-BG. METHODS Limiting dilution and xenograft studies were conducted to define the activity of 4-HC and 4-hydroperoxydidechlorocyclophosphamide with or without O6-BG. RESULTS The activity of 4-HC and 4-hydroperoxydidechlorocyclophosphamide against D283 Med (4-HCR) was increased after AGT depletion by O6-BG preincubation. Similar studies with Chinese hamster ovary cells, with or without stable transfection with a plasmid expressing the human AGT protein, revealed that the AGT-expressing cells were significantly less sensitive to 4-HC and 4-hydroperoxydidechlorocyclophosphamide. Reaction of DNA with 4-HC, phosphoramide mustard, or acrolein revealed that only 4-HC and acrolein caused a decrease in AGT levels. CONCLUSIONS We propose that a small but potentially significant part of the cellular toxicity of cyclophosphamide in these cells is due to acrolein, and that this toxicity is abrogated by removal of the acrolein adduct from DNA by AGT.
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Affiliation(s)
- H S Friedman
- Department of Pediatrics, Duke University Medical Center, Durham, NC 27710, USA
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Dong Q, Johnson SP, Colvin OM, Bullock N, Kilborn C, Runyon G, Sullivan DM, Easton J, Bigner DD, Nahta R, Marks J, Modrich P, Friedman HS. Multiple DNA repair mechanisms and alkylator resistance in the human medulloblastoma cell line D-283 Med (4-HCR). Cancer Chemother Pharmacol 1999; 43:73-9. [PMID: 9923544 DOI: 10.1007/s002800050865] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
PURPOSE We have previously reported preferential repair of DNA interstrand crosslinks in the 4-hydroperoxycyclophosphamide-resistant human medulloblastoma cell line D-283 Med (4-HCR). We now report further studies that explored the potential mechanisms underlying this repair. METHODS Limiting dilution assays and Western, Southern, and Northern blots were used to compare specific differences between D-283 Med (4-HCR) and its parental line D-283 Med. RESULTS D-283 Med (4-HCR) was cross-resistant to melphalan and 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU), with O6-alkylguanine-DNA alkyltransferase (AGT) levels of 466+/-164 fmol/mg protein; AGT levels in the parental line, D-283 Med, were 76+/-96 fmol/mg. The increase in AGT activity was not a result of gene amplification. Depleting AGT with O6-benzylguanine partially restored sensitivity to BCNU. Both cell lines were deficient in the human mismatch protein MutLalpha. ERCC4 mRNA and poly(ADP-ribose) polymerase levels were similar in both cell lines, and ERCC1 mRNA levels were 2- to 2.5-fold lower in D-283 Med (4-HCR). Topoisomerase I levels were 2- to 2.5-fold higher in D-283 Med compared with D-283 Med (4-HCR). CONCLUSION These results, while illustrating the multiple differences between D-283 Med and D-283 Med (4-HCR), do not explain the enhanced DNA interstrand crosslink repair seen in D-283 Med (4-HCR).
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Affiliation(s)
- Q Dong
- Department of Pediatrics, Duke University Medical Center, Durham, NC 27710, USA
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Loomer DC, Johnson SP, Diffin DC, DeMaioribus CA. Superior mesenteric artery stent placement in a patient with acute mesenteric ischemia. J Vasc Interv Radiol 1999; 10:29-32. [PMID: 10872486 DOI: 10.1016/s1051-0443(99)70005-9] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Affiliation(s)
- D C Loomer
- Department of Radiology, USAF Medical Center, Lackland AFB, TX 78236, USA
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25
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Goldstein T, Johnson SP, Werner LJ, Nolan S, Hilliard BA. Causes of erroneous white blood cell counts and differentials in clinically healthy young northern elephant seals (Mirounga angustirostris). J Zoo Wildl Med 1998; 29:408-12. [PMID: 10065848] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/11/2023] Open
Abstract
From 1993 to 1995, approximately 10% of the clinically healthy northern elephant seals (Mirounga angustirostris) at The Marine Mammal Center in California exhibited a large unexplained increase in their white blood cell (WBC) count. In these animals, WBC counts ranged from 28,780 to 125,000/mm3, with a mean of 50,087/mm3. Significant correlations between the leukocytosis and weight gain and day of admittance were identified, but no correlation existed between leukocytosis and general state of health, sex, length of stay, or diet. Bone marrow contamination of blood samples, erroneous automated leukocyte counts, and leukogram changes consistent with subclinical inflammation were the major factors contributing to the elevated WBC counts in these apparently clinically healthy animals.
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Affiliation(s)
- T Goldstein
- The Marine Mammal Center, Marin Headlands, Golden Gate National Recreation Area, Sausalito, California 94965, USA
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26
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Abstract
Ninety-six 4-month-old infants were habituated to one of three computer-generated displays depicting two rod parts above and below an occluding box. In the first display, the surfaces and boundaries of the rod and box were specified by dense surface texture. Their depth segregation was specified by accretion and deletion of background texture and motion shear. In the second display, the unity of the rod parts and box, and their depth segregation, were specified only by illusory contours. In the third display, the boundaries of the rod and box were specified by illusory contours, perceptible only via spatiotemporal integration of accretion and deletion of sparse-background-texture elements. Infants appeared to perceive object unity, and segregate the rod and box surfaces, in all three displays, indicating use of illusory contours to perceive bounded surfaces in depth. The results suggest a cognitive contribution to perception of some illusory contours, abilities which seem to be present by at least 4 months of age.
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Affiliation(s)
- S P Johnson
- Department of Psychology, Texas A&M University, College Station 77843, USA.
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Diffin DC, Leyendecker JR, Johnson SP, Zucker RJ, Grebe PJ. Effect of anatomic distribution of pulmonary emboli on interobserver agreement in the interpretation of pulmonary angiography. AJR Am J Roentgenol 1998; 171:1085-9. [PMID: 9763002 DOI: 10.2214/ajr.171.4.9763002] [Citation(s) in RCA: 164] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
OBJECTIVE This study examines the anatomic distribution of emboli on pulmonary angiography and attempts to determine the relationship of vessel size to interobserver agreement, two factors having important implications in comparing pulmonary angiography with cross-sectional imaging for pulmonary embolism. MATERIALS AND METHODS One hundred twenty-five consecutive pulmonary angiograms were reviewed retrospectively by three interventional radiologists. Initial interpretations were recorded and compared to determine interobserver agreement on a per-patient and per-embolus basis. Discordant interpretations were reviewed by all radiologists for a consensus interpretation. RESULTS Unanimous per-patient agreement occurred in 91% (114/125) of initial interpretations. The largest artery containing acute pulmonary embolism was segmental or larger in 24 patients (83% of patients with acute positive findings, 19% of all patients) and subsegmental in only five patients (17% and 4%, respectively). On a per-patient basis, initial interobserver agreement averaged 45% and unanimous consensus agreement was achieved for 79% of patients having isolated subsegmental pulmonary embolism. Consensus readings altered initial per-patient interpretations for 30% of patients having only subsegmental pulmonary embolism; per-embolus interpretations were altered for 37% of all subsegmental emboli. CONCLUSION Subsegmental emboli occurring as isolated findings are relatively rare. Approximately one third of subsegmental emboli and one third of patients having isolated subsegmental emboli may be initially misdiagnosed on pulmonary angiography. Objections to cross-sectional imaging for pulmonary embolism based on the inability to detect subsegmental pulmonary embolism when compared with pulmonary angiography should be reexamined with this data in mind.
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Affiliation(s)
- D C Diffin
- Department of Radiology, MTRD, Wilford Hall Medical Center, Lackland Air Force Base, TX 78236-5300, USA
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Johnson SP, Nolan S, Gulland FM. Antimicrobial susceptibility of bacteria isolated from pinnipeds stranded in central and northern California. J Zoo Wildl Med 1998; 29:288-94. [PMID: 9809600] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2023] Open
Abstract
Over a 2-yr period (1994-1995), the antimicrobial susceptibilities of 129 bacterial isolates recovered from live stranded California sea lions (Zalophus californianus), harbor seals (Phoca vitulina), and northern elephant seals (Mirounga angustirostris) were studied. Nineteen genera of bacteria were isolated from various sites of inflammation; abscesses and umbilici were the most common sites. Seventy-two percent of the bacterial isolated were gram negative, and the Enterobacteriaceae (Escherichia coli, Proteus spp., Klebsiella spp., Salmonella spp.) accounted for 75% of the gram-negative isolates. All of the gram-positive isolates were either Enterococcus spp. or Staphylococcus aureus. Multiple drug resistance was present in all but one of the bacterial isolates. The gram-positive bacteria were most susceptible to amoxicillin-clavulanic acid (77% of 36 isolates) and least susceptible to lincomycin (18% of 11 isolates). The gram-negative bacteria were most susceptible to amikacin (91% of 91 isolates) and least susceptible to clindamycin (3% of 109 isolates).
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Affiliation(s)
- S P Johnson
- The Marine Mammal Center, Golden Gate National Recreation Area, Sausalito, California 94965, USA
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Johnson SP, Raiken DP, Grebe PJ, Diffin DC, Leyendecker JR. Single institution prospective evaluation of the over-the-wire Greenfield vena caval filter. J Vasc Interv Radiol 1998; 9:766-73. [PMID: 9756064 DOI: 10.1016/s1051-0443(98)70389-6] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
PURPOSE To assess the technical and clinical success of the over-the-wire (OTW) Greenfield inferior vena caval (IVC) filter. MATERIALS AND METHODS Prospective evaluation of the OTW Greenfield filter in 47 patients was performed during the course of 18 months. Technical success and deployment problems were documented. Caval perforation, leg asymmetry, and tilt were evaluated with a postprocedure, noncontrast computed tomographic (CT) scan. Follow-up was performed at 6- and 12-month intervals after the procedure and included a clinical history, chart review, and magnetic resonance (MR) imaging examination of the IVC. RESULTS Ninety-one percent of filters were placed without technical difficulties and 100% were successfully deployed. Technical difficulties included sheath kinking prior to deployment (n = 3), initial incomplete filter opening (n = 1), and wire entrapment within the filter (n = 1). Of 38 patients evaluated with CT, there was no case of caval perforation. Twenty-one patients (55%) demonstrated tilt and 14 (37%) had leg asymmetry. Tilting occurred more frequently when the filter was placed from a femoral approach (51%) than from a jugular approach (12%). Of patients with leg asymmetry, the vena cava was narrow in anteroposterior (AP) dimension in five (36%). Of 13 deaths, none were attributed to pulmonary embolism. One patient (2%) had a recurrent pulmonary embolus. Two of 16 patients (12%) with MR imaging follow-up had documented IVC thrombosis. CONCLUSIONS The OTW Greenfield filter has an effective delivery system, with few difficulties encountered during deployment. Filter tilt and leg asymmetry are common. The etiology of leg asymmetry is likely multifactorial but is often associated with a cava with a small AP diameter. Because OTW deployment appears to offer no benefit in centering the filter, the authors have elected to remove the wire prior to filter deployment to avoid possible entanglement. MR imaging follow-up reveals an acceptable incidence of IVC thrombosis.
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Affiliation(s)
- S P Johnson
- Department of Radiology, Wilford Hall Medical Center, San Antonio, TX 78236, USA
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Leyendecker JR, Elsass KD, Johnson SP, Diffin DC, Cull DL, Light JT, Dawson DL. The role of infrapopliteal MR angiography in patients undergoing optimal contrast angiography for chronic limb-threatening ischemia. J Vasc Interv Radiol 1998; 9:545-51. [PMID: 9684821 DOI: 10.1016/s1051-0443(98)70319-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
PURPOSE To determine the benefit of infrapopliteal magnetic resonance angiography (MRA) in patients with chronic limb-threatening ischemia who have undergone optimal contrast angiography (CA). PATIENTS AND METHODS Thirty-four patients (37 limbs) with limb-threatening chronic lower extremity ischemia underwent MRA and CA of the symptomatic extremity. Selective, vasodilator-enhanced digital subtraction angiography of the infrapopliteal vessels was possible for 34 limbs. Two vascular surgeons retrospectively formulated treatment plans based on CA. They then formulated treatment plans based on CA and MRA together. RESULTS CA clearly visualized 495 of 888 vascular segments as patent, while MRA clearly visualized 412 of 888 segments. Treatment plans differed for at least one of two surgeons in eight limbs, but MRA would possibly have improved clinical outcome in only one. The amount of inflow disease did not appear to influence segment visualization or treatment planning. In eight of 11 limbs that eventually required below- or above-knee amputation, CA clearly visualized more vascular segments than MRA. One patient developed renal insufficiency after CA. CONCLUSION Most patients undergoing optimal CA for chronic limb-threatening ischemia will not benefit from the addition of MRA. However, MRA should be considered when CA is suboptimal and when it is necessary to conserve contrast material.
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Affiliation(s)
- J R Leyendecker
- Department of Radiology, Wilford Hall Medical Center, Lackland AFB, TX 78236, USA
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Lee SE, Johnson SP, Hale LP, Li J, Bullock N, Fuchs H, Friedman A, McLendon R, Bigner DD, Modrich P, Friedman HS. Analysis of DNA mismatch repair proteins in human medulloblastoma. Clin Cancer Res 1998; 4:1415-9. [PMID: 9626457] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
During replication, the primary function of the eukaryotic DNA mismatch repair (MMR) system is to recognize and correct mismatched base pairs within the DNA helix. Deficiencies in MMR have been reported previously in cases of hereditary nonpolyposis colorectal cancer and sporadic tumors occurring in a variety of tissues including gliomas. Furthermore, recent evidence indicates that the MMR system may be involved in mediating therapeutic sensitivity to alkylating agents. In this study, 22 neoplastic tissue samples from 22 patients who underwent surgical resection for medulloblastoma, a common cerebellar tumor of childhood, were assayed for the presence or absence of MMR polypeptides using Western blot and immunohistochemical techniques. Results from these experiments indicate that the MMR system is not commonly deficient in medulloblastoma.
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Affiliation(s)
- S E Lee
- Department of Pathology, Duke University Medical Center, Durham, North Carolina 27710, USA
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32
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Affiliation(s)
- C E Johnson
- Wilford Hall Medical Center, Lackland Air Force Base, TX 78236, USA
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Leyendecker JR, Rivera E, Washburn WK, Johnson SP, Diffin DC, Eason JD. MR angiography of the portal venous system: techniques, interpretation, and clinical applications. Radiographics 1997; 17:1425-43. [PMID: 9397456 DOI: 10.1148/radiographics.17.6.9397456] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Magnetic resonance (MR) angiography is a noninvasive means of assessing the portal venous system that has potential advantages over currently used modalities. Time-of-flight and phase-contrast MR angiography are useful techniques that differ fundamentally in their means of data acquisition but are comparable in their ability to demonstrate normal anatomy as well as abnormalities of the portal venous system. Occasionally, artifacts caused by respiratory motion, implanted metallic devices or surgical clips, in-plane saturation, or areas of complex flow are seen at MR angiography of the portal venous system. However, most artifacts can easily be identified as such and either remedied or ignored. In addition, the suppression of signal from surrounding soft tissues may result in poor detection of parenchymal lesions. The utility of standard projection angiograms and source images can be increased through the use of intravenously administered contrast material and postprocessing techniques such as partial-volume maximum intensity projection reconstructions and shaded surface renderings. In addition to providing information on portal venous anatomy and portosystemic collateral vessels, MR angiography of the portal vein has clinical application in portal venous thrombosis and stenosis, liver transplantation, and the evaluation and planning of surgical and transjugular intrahepatic portosystemic shunts.
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Affiliation(s)
- J R Leyendecker
- Department of Radiology, Wilford Hall Medical Center, Lackland Air Force Base, San Antonio, TX 78236-5300, USA
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Leyendecker JR, Johnson SP, Diffin DC, Elsass K, Bifano SL. Time-of-flight MR arteriography of below-knee arteries with maximum-intensity-projection reconstruction: is interpretation of the axial source images helpful? AJR Am J Roentgenol 1997; 169:1145-9. [PMID: 9308479 DOI: 10.2214/ajr.169.4.9308479] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
OBJECTIVE We evaluated the extent to which detailed review of axial source images enhances the interpretation of projectional reconstructions of two-dimensional time-of-flight MR arteriograms of the tibial vessels. SUBJECTS AND METHODS Thirty-one patients (34 limbs) with limb-threatening ischemia underwent two-dimensional time-of-flight imaging and contrast-enhanced angiography of the below-knee arteries. Maximum-intensity-projection (MIP) reconstructions of the MR arteriograms were independently interpreted by three observers. The studies were then reinterpreted after detailed review of the axial source images. A consensus reading of each study was performed as well. The observers commented on the patency of 816 vascular segments and graded the extent of disease for 272 vessels. Interobserver agreement and correlation with contrast-enhanced angiography were determined. RESULTS On average, the addition of axial images altered the observers' interpretation of MR arteriograms in 13% of segments for patency and in 18% of vessels for grading of disease severity. For determining the patency of vascular segments, mean interobserver agreement was 0.79 without and 0.80 with axial image interpretation, and mean agreement with contrast-enhanced angiography improved from 0.69 to 0.72 with the addition of axial images. When evaluating the extent of disease, correlation between observers improved for all combinations of observers with the addition of axial images, and correlation with contrast-enhanced angiography improved for two of three observers. Based on the consensus interpretation of the MR arteriograms, review of axial images was found to improve agreement with contrast-enhanced angiography in 34 vascular segments. In addition, axial image review correctly altered the number of stenoses identified in 12 vessels. When consensus interpretation identified a vessel as patent without significant stenosis on the MIP images, the MIP-based interpretation was found to be correct in all cases. CONCLUSION Review of axial source images provides limited benefit to interpretation of MR arteriograms of the distal lower extremity in patients with peripheral vascular disease. Although selective review of axial source images may be appropriate, axial images can improve interpretation when MIP images are complicated by the presence of patient motion, difficult anatomy, or artifacts. Axial image review may also be appropriate when a significant stenosis is identified on the MIP images.
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Affiliation(s)
- J R Leyendecker
- Department of Radiology/PSRD, Wilford Hall Medical Center, Lackland Air Force Base, TX 78236, USA
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Carrier DA, Arriaga MA, Gorum MJ, Dahlen RT, Johnson SP. Preoperative embolization of anastomoses of the jugular bulb: an adjuvant in jugular foramen surgery. AJNR Am J Neuroradiol 1997; 18:1252-6. [PMID: 9282850 PMCID: PMC8338038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
We describe the technique of preoperative embolization of the inferior petrosal sinus/anterior condylar vein complex and the posterior condylar vein in three patients undergoing skull base surgery that required opening of the jugular bulb. Contrary to the usual situation, essentially no blood was lost during the operation, resulting in decreased surgical time and reduced risk to the lower cranial nerves.
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Affiliation(s)
- D A Carrier
- Department of Radiology, Wilford Hall Medical Center, Lackland Air Force Base, Texas, USA
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Friedman HS, Johnson SP, Dong Q, Schold SC, Rasheed BK, Bigner SH, Ali-Osman F, Dolan E, Colvin OM, Houghton P, Germain G, Drummond JT, Keir S, Marcelli S, Bigner DD, Modrich P. Methylator resistance mediated by mismatch repair deficiency in a glioblastoma multiforme xenograft. Cancer Res 1997; 57:2933-6. [PMID: 9230204] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
A methylator-resistant human glioblastoma multiforme xenograft, D-245 MG (PR), in athymic nude mice was established by serially treating the parent xenograft D-245 MG with procarbazine. D-245 MG xenografts were sensitive to procarbazine, temozolomide, N-methyl-N-nitrosourea, 1,3-bis(2-chloroethyl)-1-nitrosourea, 9-aminocamptothecin, topotecan, CPT-11, cyclophosphamide, and busulfan. D-245 MG (PR) xenografts were resistant to procarbazine, temozolomide, N-methyl-N-nitrosourea, and busulfan, but they were sensitive to the other agents. Both D-245 MG and D-245 MG (PR) xenografts displayed no O6-alkylguanine-DNA alkyltransferase activity, and their levels of glutathione and glutathione-S-transferase were similar. D-245 MG xenografts expressed the human mismatch repair proteins hMSH2 and hMLH1, whereas D-245 MG (PR) expressed hMLH1 but not hMSH2.
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Affiliation(s)
- H S Friedman
- Department of Pediatrics, Duke University Medical Center, Durham, North Carolina 27710, USA
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Abstract
1. Broiler chickens were killed using 90% argon in air, or 30% carbon dioxide and 60% argon in air or 120 mA per bird in a waterbath with a 50 Hz alternating electric current. Ventral or unilateral neck cutting was performed at 1, 3 or 5 min after killing. In addition, a group of broilers was stunned with 120 mA per bird in a waterbath using 1500 Hz alternating current and were bled out-with a ventral neck cut within 20 s from stunning. 2. Blood leaving the neck wound was collected in a bin placed on an electronic balance and a computer program calculated the cumulative blood loss up to 100 s after neck cutting. 3. Bleed-out was significantly affected by killing method and time of neck cutting. Broilers killed with the carbon dioxide-argon mixture bled-out less than those killed with argon or 50 Hz electric current. When compared with the 1 min neck cutting interval, a delay of 3-or 5 min resulted in a lower bleed-out. High frequency electrical stunning and ventral neck cutting within 20 s resulted in a slightly higher bleed-out than those recorded for the killing methods. However, within argon killing, a delay of 3 or 5 min in ventral or unilateral neck cutting had no significant effect on the bleed-out. In broilers killed with the carbon dioxide-argon mixture a 3 min delay in ventral neck cutting or a 5 min delay in unilateral neck cutting resulted in lower bleed-out. 4. Neck cutting of broilers within 5 min after argon killing or 3 min after killing with the carbon dioxide-argon mixture would result in a satisfactory bleed-out.
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Affiliation(s)
- A B Raj
- Division of Food Animal Science, University of Bristol, England
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Raj AB, Johnson SP, Wotton SB, McInstry JL. Welfare implications of gas stunning pigs: 3. The time to loss of somatosensory evoked potentials and spontaneous electrocorticogram of pigs during exposure to gases. Vet J 1997; 153:329-39. [PMID: 9232122 DOI: 10.1016/s1090-0233(97)80067-6] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Changes in the spontaneous electrocorticogram (ECoG) and somatosensory evoked potentials (SEPs) were recorded in 12 pigs in each of three gas killing treatments. The treatments were 90% argon in air with 2% residual oxygen; a mixture of 30% carbon dioxide and 60% argon in air with 2% residual oxygen; or 80-90% carbon dioxide in air. The mean times to loss of SEPs were 15, 17 and 21 s, respectively. The mean time to loss of SEPs recorded during killing with a high concentration of carbon dioxide was significantly longer than those recorded for the other two gas killing treatments (P < 0.05). Slow waves (high amplitude and low frequency) appeared on average 15 s after exposure to argon. In some pigs killed with the carbon dioxide-argon mixture, a decrease in the frequency of electrical activity was apparent, although slow waves did not appear during killing with a higher concentration of carbon dioxide. A suppressed ECoG (reduction in amplitude of signals) was recorded at 22 and 20 s respectively, during exposure to the carbon dioxide-argon mixture and 80-90% carbon dioxide in air, but the onset of ECoG suppression could not be determined exactly during exposure to 90% argon in air. The time to onset of an isoelectric ECoG was 54, 39d and 32 s after exposure to argon, carbon dioxide-argon mixture and a high concentration of carbon dioxide, respectively. The mean time to the onset of an isoelectric ECoG during exposure to argon was significantly longer than that recorded for the other two gas killing treatments (P < 0.05). Based on the time to loss of SEPs, it is concluded that during killing with a high concentration of carbon dioxide, pigs would have to endure a moderate to severe respiratory distress induced with this gas for a considerable period of time prior to the loss of brain responsiveness. Argon-induced anoxia appears to be the first choice from a welfare point of view for killing pigs, based on its lack of aversive properties and its effectiveness in rapidly abolishing brain responsiveness. A mixture of 30% carbon dioxide and 60% argon in air is considered to be more humane than using a high concentration of carbon dioxide, as the time to loss of brain responsiveness is similar to that using 90% argon in air.
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Affiliation(s)
- A B Raj
- Department of Clinical Veterinary Science, University of Bristol, Langford, UK
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Raj AB, Wilkins LJ, Richardson RI, Johnson SP, Wotton SB. Carcase and meat quality in broilers either killed with a gas mixture or stunned with an electric current under commercial processing conditions. Br Poult Sci 1997; 38:169-74. [PMID: 9158892 DOI: 10.1080/00071669708417964] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
1. Carcase and meat quality were evaluated under commercial conditions in 400 broilers either killed with a mixture of 30% carbon dioxide and 60% argon in air or stunned with a 50 Hz AC with clipped sine wave. 2. Compared with electrical stunning, killing broilers with the gas mixture eliminated or substantially reduced the prevalence of carcase and meat quality defects. 3. The results also showed that killing broilers with a mixture of 30% carbon dioxide and 60% argon would enable filleting (deboning) to be performed at 4 h post mortem without adversely affecting the cook loss or texture of breast meat.
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Affiliation(s)
- A B Raj
- Division of Food Animal Science, University of Bristol, England
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40
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Johnson SP, Fujitani RM, Leyendecker JR, Joseph FB. Stent deformation and intimal hyperplasia complicating treatment of a post-carotid endarterectomy intimal flap with a Palmaz stent. J Vasc Surg 1997; 25:764-8. [PMID: 9129637 DOI: 10.1016/s0741-5214(97)70308-2] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
We report a case of common carotid artery Palmaz stent placement for treatment of an intimal flap after surgical endarterectomy. Despite technical success with an excellent immediate result, a significant stenosis detected by duplex sonographic examination developed at 10 months. This stenosis, the result of stent compression and intimal hyperplasia, illustrates the previously theoretic risk associated with placement of the balloon-expandable stent in a compressible site such as the cervical carotid artery. In addition, we demonstrate that significant intimal hyperplasia may occur after carotid artery stent placement, potentially limiting long-term patency.
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Affiliation(s)
- S P Johnson
- Department of Radiology, Wilford Hall Medical Center, Lackland AFB, TX 78236-5300, USA
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41
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Johnson SP. Fluoxetine and amitriptyline in the treatment of fibromyalgia. J Fam Pract 1997; 44:128-130. [PMID: 9040508] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Affiliation(s)
- S P Johnson
- University of Virginia, Charlottesville, USA.
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Abstract
In an ongoing study involving seven hospitals in London and surrounding areas, 55,237 fetuses were examined by ultrasound at 10-14 weeks of gestation. There were 47 fetuses (1 in 1175) with anencephaly which presented with acrania with varying degrees of cerebral degeneration. The first audit of results was performed in April 1995. During the first phase of the study 34,830 fetuses were examined and in eight of the 31 with anencephaly the diagnosis was not made at the 10-14-week scan. Following the audit, 20,407 fetuses were examined and in all 16 with anencephaly the diagnosis was made at the 10-14-week scan (p = 0.03). These findings demonstrate that anencephaly can be reliably diagnosed at the routine 10-14-week ultrasound scan, provided a specific search is made for the sonographic features for this condition.
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Affiliation(s)
- S P Johnson
- Harris Birthright Research Centre for Fetal Medicine, King's College Hospital Medical School, London, UK
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Johnson SP, Leyendecker JR, Joseph FB, Joseph AE, Diffin DC, Devoid D, Eason J. Transjugular portosystemic shunts in pediatric patients awaiting liver transplantation. Transplantation 1996; 62:1178-81. [PMID: 8900323 DOI: 10.1097/00007890-199610270-00027] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Three pediatric patients from 6 to 11 years of age awaiting liver transplantation for end stage liver disease underwent transjugular intrahepatic portosystemic shunt (TIPS) placement for control of variceal bleeding. Two of the three procedures were performed emergently after endoscopic sclerotherapy failed to stop active bleeding. One procedure was performed electively after multiple prior bleeding episodes. The shunts were created from the middle or left hepatic vein to the left portal vein, and none of the subsequent transplant surgeries was complicated by the presence of the stents. No major or minor complications were related to TIPS placement. Two patients underwent concomitant variceal embolization. Bleeding was successfully controlled in each patient. We conclude that TIPS placement in children is technically feasible, does not complicate subsequent surgery, and is useful treating acute variceal hemorrhage in pediatric patients awaiting liver transplantation.
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Affiliation(s)
- S P Johnson
- Department of Radiology, Wilford Hall Medical Center, Lackland Air Force Base, San Antonio, Texas 78236-5300, USA
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44
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Wood JD, Brown SN, Nute GR, Whittington FM, Perry AM, Johnson SP, Enser M. Effects of breed, feed level and conditioning time on the tenderness of pork. Meat Sci 1996; 44:105-12. [PMID: 22060760 DOI: 10.1016/s0309-1740(96)00044-7] [Citation(s) in RCA: 98] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/1995] [Accepted: 03/20/1996] [Indexed: 11/28/2022]
Affiliation(s)
- J D Wood
- Division of Food Animal Science, School of Veterinary Science, University of Bristol, Langford, Bristol BS18 7DY, UK
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45
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Leyendecker JR, Buehrer JL, Johnson SP, McDonald KD. Thrombosed superficial femoral artery aneurysms in a child: failure of limb salvage with catheter-directed thrombolysis. J Vasc Interv Radiol 1996; 7:691-4. [PMID: 8897334 DOI: 10.1016/s1051-0443(96)70830-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Affiliation(s)
- J R Leyendecker
- Department of Radiology, Wilford Hall Medical Center, TX 78236, USA
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46
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Abstract
We have studied the DNA sequence elements of the murine MHC class II A beta gene involved in transcriptional regulation in macrophages. For this study, the A beta promoter was fused to the human growth hormone gene and transfected into bone marrow-derived macrophages. These macrophages were stimulated by interferon-gamma (IFN-gamma), after which cellular RNA was assayed for the amount of human growth hormone transcripts. A -146 to +14 fragment of the A beta promoter was found to be sufficient to confer positive regulation by IFN-gamma. Induction was suppressed by bacterial lipopolysaccharide, tumor necrosis factor (TNF-alpha), or maley-lated bovine serum albumin. Substitution mutations were made within each of the conserved sequence elements of the promoter as well as within the spacer regions between these elements. All four conserved sequences found in class II promoters, the H, X1, X2, and Y elements, were found to be essential for promoter activation in macrophages.
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Affiliation(s)
- S P Johnson
- Department of Pathology, Duke University Medical Center, Durham, North Carolina 27710, USA
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47
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Pandya PP, Snijders RJ, Johnson SP, De Lourdes Brizot M, Nicolaides KH. Screening for fetal trisomies by maternal age and fetal nuchal translucency thickness at 10 to 14 weeks of gestation. Br J Obstet Gynaecol 1995; 102:957-62. [PMID: 8652486 DOI: 10.1111/j.1471-0528.1995.tb10902.x] [Citation(s) in RCA: 302] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
OBJECTIVE To evaluate screening for chromosomal defects by a combination of fetal nuchal translucency thickness and maternal age. DESIGN A prospective multicentre screening study where fetal nuchal translucency thickness was measured at 10 to 14 weeks of gestation. SUBJECTS 20,804 women with singleton pregnancies screened at 10 to 14 weeks of gestation from 1 September 1992 to 28 October 1994. MAIN OUTCOME MEASURES Trisomy 21 and other chromosomal defects identified by increased nuchal translucency thickness and by a combination of nuchal translucency thickness and maternal age. RESULTS In normal fetuses nuchal translucency thickness increased significantly with crown-rump length. The nuchal translucency was above the 95th centile in 77% (66 of 86) of fetuses with trisomy 21 and in 78% (61 of 78) of those with other chromosomal defects. On the basis of the distribution of nuchal translucency measurements in normal fetuses and those with trisomy 21, a new method of screening is proposed which involves assessment of individual risk based on the combination of fetal nuchal translucency, crown-rump length and maternal age. The minimum risk was 1/100 in 4.9% of the normal pregnancies, in 80% of those with trisomy 21 and in 77% of those with other chromosomal defects. CONCLUSION Screening for fetal trisomy 21 can be carried out effectively during the first trimester of pregnancy.
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Affiliation(s)
- P P Pandya
- Harris Birthright Research Centre for Fetal Medicine, King's College Hospital Medical School, London, UK
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48
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Abstract
Hepatopulmonary syndrome is a complication of chronic liver disease in which arterial hypoxemia results from abnormalities in pulmonary blood flow. Severe hypoxemia can lead to clinical deterioration and death. Although the etiology is unknown, portal hypertension seems to be an important factor in the development of hepatopulmonary syndrome. No effective pharmacological therapy has been identified, but liver transplantation may be curative. Arterial hypoxemia may complicate transplant surgery, however, and resolution of the syndrome after liver transplantation is performed may be delayed. In addition, it seems that complete reversal of oxygenation abnormalities after liver transplantation is performed is unpredictable. We described a patient with hepatopulmonary syndrome who noted improvement in symptoms of dyspnea after the placement of a transjugular intrahepatic portosystemic shunt. Arterial oxygenation and calculated shunt fraction improved significantly during the follow-up period, and liver transplantation was subsequently performed without difficulty. Portal decompression using transjugular intrahepatic portosystemic shunt may represent a palliative therapy for hepatopulmonary syndrome in patients awaiting liver transplantation.
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Affiliation(s)
- J L Riegler
- Department of Medicine, Wilford Hall Medical Center, Lackland Air Force Base, Texas, USA
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Vonstein V, Johnson SP, Yu H, Casadaban MJ, Pagratis NC, Weber JM, Demirjian DC. Molecular cloning of the pyrE gene from the extreme thermophile Thermus flavus. J Bacteriol 1995; 177:4540-3. [PMID: 7635839 PMCID: PMC177211 DOI: 10.1128/jb.177.15.4540-4543.1995] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Mutants of the extreme thermophile Thermus flavus in the pyrimidine biosynthetic pathway (Pyr-) were isolated by resistance to 5-fluoroorotic acid. The pyrE gene, which codes for the orotate phosphoribosyltransferase, was cloned by recombination with one of the isolated Pyr- T. flavus mutant strains. It was subcloned by complementation of an Escherichia coli pyrE mutant strain and was sequenced. The deduced polypeptide sequence extends over 183 amino acids. Several independent Pyr- mutations were mapped within the pyrE locus by recombination with fragments of the cloned gene.
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Affiliation(s)
- V Vonstein
- ThermoGen, Inc., Chicago, Illinois 60612, USA
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50
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Thai SF, Lewis JG, Williams RB, Johnson SP, Adams DO. Effects of oxidized LDL on mononuclear phagocytes: inhibition of induction of four inflammatory cytokine gene RNAs, release of NO, and cytolysis of tumor cells. J Leukoc Biol 1995; 57:427-33. [PMID: 7884314 DOI: 10.1002/jlb.57.3.427] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
A critical step in development of atherosclerosis is the interaction of oxidized low-density lipoprotein (LDL) with mononuclear phagocytes. Oxidized LDL, as well as acetyl-LDL, is rapidly taken up into macrophages via a family of scavenger receptors. We report that macrophages treated with oxidized LDL have markedly lower levels of mRNA specific for the genes MCP-1, TNF-alpha, IL-1 alpha, and KC as measured by Northern blot analyses of lipopolysaccharide (LPS)-stimulated macrophages. By contrast, acetyl-LDL does not inhibit these genes at the doses at which oxidized-LDL is effective. Similar effects are observed whether the LDL is oxidized in the presence of Cu2+ or of Fe2+. Such inhibition also occurs when maleylated bovine serum albumin (BSA), which also clears by one or more scavenger receptors on macrophages, is used as the stimulant. Fe2+ or Cu2+ oxidized LDL inhibits release of nitric oxide when triggered by LPS and direct cytolysis of tumor cells when triggered by maleylated BSA or LPS. Taken together, the data presented indicate that oxidized LDL inhibits induction of several important gene RNAs as well as functional markers that characterize the development of inflammatory and fully activated macrophages.
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Affiliation(s)
- S F Thai
- Department of Pathology, Duke University Medical Center, Durham, North Carolina 27710
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