1
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Kratochvil MJ, Kaber G, Demirdjian S, Cai PC, Burgener EB, Nagy N, Barlow GL, Popescu M, Nicolls MR, Ozawa MG, Regula DP, Pacheco-Navarro AE, Yang S, de Jesus Perez VA, Karmouty-Quintana H, Peters AM, Zhao B, Buja ML, Johnson PY, Vernon RB, Wight TN, Milla CE, Rogers AJ, Spakowitz AJ, Heilshorn SC, Bollyky PL. Biochemical, biophysical, and immunological characterization of respiratory secretions in severe SARS-CoV-2 infections. JCI Insight 2022; 7:152629. [PMID: 35730564 PMCID: PMC9309048 DOI: 10.1172/jci.insight.152629] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2021] [Accepted: 05/10/2022] [Indexed: 01/27/2023] Open
Abstract
Thick, viscous respiratory secretions are a major pathogenic feature of COVID-19, but the composition and physical properties of these secretions are poorly understood. We characterized the composition and rheological properties (i.e., resistance to flow) of respiratory secretions collected from intubated COVID-19 patients. We found the percentages of solids and protein content were greatly elevated in COVID-19 compared with heathy control samples and closely resembled levels seen in cystic fibrosis, a genetic disease known for thick, tenacious respiratory secretions. DNA and hyaluronan (HA) were major components of respiratory secretions in COVID-19 and were likewise abundant in cadaveric lung tissues from these patients. COVID-19 secretions exhibited heterogeneous rheological behaviors, with thicker samples showing increased sensitivity to DNase and hyaluronidase treatment. In histologic sections from these same patients, we observed increased accumulation of HA and the hyaladherin versican but reduced tumor necrosis factor-stimulated gene-6 staining, consistent with the inflammatory nature of these secretions. Finally, we observed diminished type I interferon and enhanced inflammatory cytokines in these secretions. Overall, our studies indicated that increases in HA and DNA in COVID-19 respiratory secretion samples correlated with enhanced inflammatory burden and suggested that DNA and HA may be viable therapeutic targets in COVID-19 infection.
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Affiliation(s)
- Michael J. Kratochvil
- Division of Infectious Diseases and Geographic Medicine, Department of Medicine, Stanford University School of Medicine, Stanford, California, USA.,Department of Materials Science and Engineering and
| | - Gernot Kaber
- Division of Infectious Diseases and Geographic Medicine, Department of Medicine, Stanford University School of Medicine, Stanford, California, USA
| | - Sally Demirdjian
- Division of Infectious Diseases and Geographic Medicine, Department of Medicine, Stanford University School of Medicine, Stanford, California, USA
| | - Pamela C. Cai
- Department of Chemical Engineering, Stanford University, Stanford, California, USA
| | | | - Nadine Nagy
- Division of Infectious Diseases and Geographic Medicine, Department of Medicine, Stanford University School of Medicine, Stanford, California, USA
| | - Graham L. Barlow
- Division of Infectious Diseases and Geographic Medicine, Department of Medicine, Stanford University School of Medicine, Stanford, California, USA
| | - Medeea Popescu
- Division of Infectious Diseases and Geographic Medicine, Department of Medicine, Stanford University School of Medicine, Stanford, California, USA
| | - Mark R. Nicolls
- Department of Pulmonology, Allergy and Critical Care Medicine
| | | | | | | | - Samuel Yang
- Department of Emergency Medicine, Stanford University School of Medicine, Stanford, California, USA
| | | | - Harry Karmouty-Quintana
- Department of Biochemistry and Molecular Biology;,Divisions of Critical Care Medicine and Pulmonary and Sleep Medicine, Department of Internal Medicine
| | | | - Bihong Zhao
- Department of Pathology and Laboratory Medicine; and,Department of Internal Medicine, University of Texas Health Science Center — McGovern Medical School, Houston, Texas, USA
| | - Maximilian L. Buja
- Department of Pathology and Laboratory Medicine; and,Department of Internal Medicine, University of Texas Health Science Center — McGovern Medical School, Houston, Texas, USA
| | - Pamela Y. Johnson
- Matrix Biology Program, Benaroya Research Institute, Seattle, Washington, USA
| | - Robert B. Vernon
- Matrix Biology Program, Benaroya Research Institute, Seattle, Washington, USA
| | - Thomas N. Wight
- Matrix Biology Program, Benaroya Research Institute, Seattle, Washington, USA
| | | | - Carlos E. Milla
- Center for Excellence in Pulmonary Biology, Department of Pediatrics
| | | | - Andrew J. Spakowitz
- Department of Chemical Engineering, Stanford University, Stanford, California, USA
| | | | - Paul L. Bollyky
- Division of Infectious Diseases and Geographic Medicine, Department of Medicine, Stanford University School of Medicine, Stanford, California, USA
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2
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Kratochvil MJ, Kaber G, Demirdjian S, Cai PC, Burgener EB, Nagy N, Barlow GL, Popescu M, Nicolls MR, Ozawa MG, Regula DP, Pacheco-navarro AE, Yang S, de Jesus Perez VA, Karmouty-quintana H, Peters AM, Zhao B, Buja ML, Johnson PY, Vernon RB, Wight TN, Milla CE, Rogers AJ, Spakowitz AJ, Heilshorn SC, Bollyky PL, Stanford COVID-19 Biobank Study Group. Biochemical, Biophysical, and Immunological Characterization of Respiratory Secretions in Severe SARS-CoV-2 (COVID-19) Infections.. [PMID: 35411348 PMCID: PMC8996635 DOI: 10.1101/2022.03.28.22272848] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Thick, viscous respiratory secretions are a major pathogenic feature of COVID-19 disease, but the composition and physical properties of these secretions are poorly understood. We characterized the composition and rheological properties (i.e. resistance to flow) of respiratory secretions collected from intubated COVID-19 patients. We find the percent solids and protein content are greatly elevated in COVID-19 compared to heathy control samples and closely resemble levels seen in cystic fibrosis, a genetic disease known for thick, tenacious respiratory secretions. DNA and hyaluronan (HA) are major components of respiratory secretions in COVID-19 and are likewise abundant in cadaveric lung tissues from these patients. COVID-19 secretions exhibit heterogeneous rheological behaviors with thicker samples showing increased sensitivity to DNase and hyaluronidase treatment. In histologic sections from these same patients, we observe increased accumulation of HA and the hyaladherin versican but reduced tumor necrosis factor–stimulated gene-6 (TSG6) staining, consistent with the inflammatory nature of these secretions. Finally, we observed diminished type I interferon and enhanced inflammatory cytokines in these secretions. Overall, our studies indicate that increases in HA and DNA in COVID-19 respiratory secretion samples correlate with enhanced inflammatory burden and suggest that DNA and HA may be viable therapeutic targets in COVID-19 infection.
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3
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Zhou Z, Peters AM, Wang S, Janda A, Chen J, Zhou P, Arthur E, Kwartler CS, Milewicz DM. Reversal of Aortic Enlargement Induced by Increased Biomechanical Forces Requires AT1R Inhibition in Conjunction With AT2R Activation. Arterioscler Thromb Vasc Biol 2019; 39:459-466. [PMID: 30602301 PMCID: PMC6400319 DOI: 10.1161/atvbaha.118.312158] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [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] [Indexed: 12/20/2022]
Abstract
Objective- Pharmacological inhibition of the AT1R (angiotensin II type 1 receptor) with losartan can attenuate ascending aortic remodeling induced by transverse aortic constriction (TAC). In this study, we investigated the role of the AT2R (angiotensin II type 2 receptor) and MasR (Mas receptor) in TAC-induced ascending aortic dilation and remodeling. Approach and Results- Wild-type C57BL/6J mice were subjected to sham or TAC surgeries in the presence and absence of various drugs. Aortic diameters were assessed by echocardiography, central blood pressure was measured in the ascending aorta 2 weeks post-operation, and histology and gene expression analyses completed. An angiotensin-converting enzyme inhibitor, captopril, decreased systolic blood pressure to the same level as losartan but did not attenuate aortic dilation, adventitial inflammation, medial collagen deposition, elastin breakage, or Mmp9 (matrix metalloproteinase-9) expression when compared with TAC mice. In contrast, co-administration of captopril with an AT2R agonist, compound 21, attenuated aortic dilation, medial collagen content, elastin breaks, and Mmp9 expression, whereas co-administration of captopril with a MasR agonist (AVE0991) did not reverse aortic dilation and led to aberrant aortic remodeling. An AT2R antagonist, PD123319, reversed the protective effects of losartan in TAC mice. Treatment with compound 21 alone showed no effect on TAC-induced aortic enlargement, blood pressure, elastin breakage, or Mmp9 expression. Conclusions- Our data indicate that when AT1R signaling is blocked, AT2R activation is a key modulator to prevent aortic dilation that occurs with TAC. These data suggest that angiotensin-converting enzyme inhibitor may not be as effective as losartan for slowing aneurysm growth because losartan requires intact AT2R signaling to prevent aortic enlargement.
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Affiliation(s)
- Zhen Zhou
- From the Division of Medical Genetics, Department of Internal Medicine, The University of Texas Health Science Center at Houston (Z.Z., A.M.P., S.W., A.J., J.C., P.Z., E.A., C.S.K., D.M.M.)
- Department of Cardiovascular Surgery, Renmin Hospital of Wuhan University, Wuhan, Hubei, People's Republic of China (Z.Z.)
| | - Andrew M Peters
- From the Division of Medical Genetics, Department of Internal Medicine, The University of Texas Health Science Center at Houston (Z.Z., A.M.P., S.W., A.J., J.C., P.Z., E.A., C.S.K., D.M.M.)
| | - Shanzhi Wang
- From the Division of Medical Genetics, Department of Internal Medicine, The University of Texas Health Science Center at Houston (Z.Z., A.M.P., S.W., A.J., J.C., P.Z., E.A., C.S.K., D.M.M.)
| | - Alexandra Janda
- From the Division of Medical Genetics, Department of Internal Medicine, The University of Texas Health Science Center at Houston (Z.Z., A.M.P., S.W., A.J., J.C., P.Z., E.A., C.S.K., D.M.M.)
| | - Jiyuan Chen
- From the Division of Medical Genetics, Department of Internal Medicine, The University of Texas Health Science Center at Houston (Z.Z., A.M.P., S.W., A.J., J.C., P.Z., E.A., C.S.K., D.M.M.)
| | - Ping Zhou
- From the Division of Medical Genetics, Department of Internal Medicine, The University of Texas Health Science Center at Houston (Z.Z., A.M.P., S.W., A.J., J.C., P.Z., E.A., C.S.K., D.M.M.)
| | - Erin Arthur
- From the Division of Medical Genetics, Department of Internal Medicine, The University of Texas Health Science Center at Houston (Z.Z., A.M.P., S.W., A.J., J.C., P.Z., E.A., C.S.K., D.M.M.)
| | - Callie S Kwartler
- From the Division of Medical Genetics, Department of Internal Medicine, The University of Texas Health Science Center at Houston (Z.Z., A.M.P., S.W., A.J., J.C., P.Z., E.A., C.S.K., D.M.M.)
| | - Dianna M Milewicz
- From the Division of Medical Genetics, Department of Internal Medicine, The University of Texas Health Science Center at Houston (Z.Z., A.M.P., S.W., A.J., J.C., P.Z., E.A., C.S.K., D.M.M.)
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Lane IF, Lumley P, Michael MF, Peters AM, McCollum CN. A Specific Thromboxane Receptor Blocking Drug, AH23848, Reduces Platelet Deposition on Vascular Grafts in Man. Thromb Haemost 2018. [DOI: 10.1055/s-0038-1647321] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
SummaryThe antithrombotic effect of a specific thromboxane A2 receptor blocking drug, AH23848, on radio-labelled platelet deposition in mature Dacron aorto-bifemoral grafts has been evaluated in patients. Thirty patients were randomly allocated to AH23848 70 mg, aspirin 300 mg plus dipyridamole 75 mg or placebo 8-hourly for 9 days. AH23848 inhibited platelet aggregarion induced by the thromboxane ,A2 mimetic U-46619; no such effect was observed with aspirin plus dipyridamole. 111In-platelet uptake was measured as the thrombogenicity index (TI) which is a measure of the daily rate of accumulation of platelets by the graft. The mean (s.e. mean) value of 0.193 (0.029) on placebo was significantly reduced to 0.115 (0.022) by AH23848 (p <0.05) but only to 0.175 (0.028) by aspirin plus dipyridamole. There was no difference in mean platelet life span between the three treatment groups. The pronounced antithrombotic effect of AH23848 implicates thromboxane ,A2 in the process of platelet deposition in arterial prostheses and demonstrates the considerable promise of thromboxane receptor blocking drugs as antithrombotic therapy.
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Affiliation(s)
- I F Lane
- The Department of Surgery, Charing Cross Hospital, London
| | - P Lumley
- Glaxo Group Research Ltd, Ware, Hertfordshire, U. K
| | - M F Michael
- Glaxo Group Research Ltd, Ware, Hertfordshire, U. K
| | - A M Peters
- Glaxo Group Research Ltd, Ware, Hertfordshire, U. K
| | - C N McCollum
- The Department of Surgery, Charing Cross Hospital, London
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5
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Abstract
SummaryThe intrahepatic kinetics of 111indium-labelled platelets have been studied using dynamic gamma camera scintigraphy immediately following injection. Platelets labelled in saline with mIn-oxine or 111In-acetylacetonate underwent rapidly reversible hepatic sequestration, indicating that they were “activated”. Platelets labelled in plasma with 111In-tropolonate, however, did not display this phenomenon. On the assumption that plasma-labelled platelets display a normal initial bio-distribution, mean intrahepatic platelet transit time, as a factor of the transit time of 99m-Tc labelled red cells, was 1.45 ± SE 0.12 (n = 6), implying the normal presence of a small intrahepatic platelet pool. Unlike the liver, transit through the spleen was not sensitive to the labelling medium; thus the mean intrasplenic transit time of plasma-labelled platelets was 9.3 ± SE 0.7 min (n = 10), and of saline-labelled platelets 9.5 ± SE 0.3 min (n = 8).
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Affiliation(s)
- A M Peters
- The Department of Diagnostic Radiology, Royal Postgraduate Medical School, London, UK
| | - S H Saverymuttu
- The Department of Medicine, Royal Postgraduate Medical School, London, UK
| | - F Malik
- The Department of Diagnostic Radiology, Royal Postgraduate Medical School, London, UK
| | - P W Ind
- The Department of Medicine, Royal Postgraduate Medical School, London, UK
| | - J P Lavender
- The Department of Diagnostic Radiology, Royal Postgraduate Medical School, London, UK
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6
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Peters AM, Lane IF, Sinclair M, Irwin JTC, McCollum CN. The Effects of Thromboxane Antagonism on the Transit Time of Platelets Through the Spleen. Thromb Haemost 2018. [DOI: 10.1055/s-0038-1657881] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
SummaryThe spleen is well-known as a site for platelet pooling, although the mechanisms controlling intrasplenic platelet transit are essentially unknown. We tested the possibility that thromboxane A2 might be involved in this control by measuring intrasplenic platelet transit time in 10 subjects receiving a specific thromboxane A2 receptor antagonist (AH23848B; 70 mg; Glaxo Group Research Ltd), in 10 receiving aspirin (300 mg) plus dipyridamole (75 mg), and in 9 receiving placebo. All doses were administered 3 times daily commencing 4 days prior to transit time measurement.Mean intrasplenic platelet transit time was measured by monitoring the kinetics of equilibration of 111In radiolabelled platelets between blood and spleen following intravenous injection. There was no difference between the mean transit time in the 3 groups of subjects, lending no support to the hypothesis that thromboxane A2 is involved in the control of platelet traffic through the spleen.
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Affiliation(s)
| | - I F Lane
- The Department of Surgery, Charing Cross Hospital, London
| | - M Sinclair
- The Department Nuclear Medicine, Charing Cross Hospital, London
| | - J T C Irwin
- The Department of Surgery, Charing Cross Hospital, London
| | - C N McCollum
- The Department of Surgery, Charing Cross Hospital, London
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7
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Zhou Z, Peters AM, Wang S, Chen J, Arthur E, Milewicz DM. Abstract 115: AT2 Receptor Regulates Ascending Aortic Dilation during AT1 Receptor Blockade in Transverse Aortic Constriction Mouse Model. Arterioscler Thromb Vasc Biol 2018. [DOI: 10.1161/atvb.38.suppl_1.115] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Introduction:
The angiotensin II (Ang II) type 1 receptor (AT1R) antagonist losartan can slow aortic enlargement in mouse models and patients with Marfan syndrome. We have previously shown that losartan attenuates aortic enlargement and remodeling induced by thoracic aortic constriction (TAC).
Objective:
We investigated the role of the Ang II type 2 receptor (AT2R) in an acute hypertensive remodeling of the ascending aorta induced by TAC.
Methods:
160 male C57BL/6J mice were subjected to TAC surgeries with 27-gauge needle or sham surgery. Echocardiography measurements were performed 2 weeks post-operation using the Vevo 3100 imaging system. Blood pressure was measured in the ascending aorta using a Millar catheter introduced through the right common carotid artery.
Results:
TAC induced significant enlargement in aortic root and ascending aorta two weeks after surgery. The angiotensin converting enzyme inhibitor, captopril, decreased intraluminal systolic blood pressure (SBP) to the same degree as losartan, but did not prevent the increased aortic dilation, adventitial inflammation, medial elastin breakage, or
Mmp9
expression compared with TAC mice. Captopril plus an AT2R agonist, compound 21 (C21) attenuated TAC-indcued aortic dilation, elastin break numbers and
Mmp9
expression similar to losartan, despite an increase in SBP compared with captopril-treated TAC mice. Consistent with these results, treatment with losartan and an AT2R antagonist, PD123319, reversed the protective effects of losartan on TAC-induced aortic enlargement and remodeling. Note that treating with captopril and a Mas receptor agonist AVE0991 did not prevent TAC-induced aortic enlargement. Importantly, treating with C21 alone did not prevent TAC-induced aortic dilation, elastin breakage or
Mmp9
expression despite significantly decreased SBP.
Conclusions:
These data indicate signaling through both AT1R and AT2R are key modulators in aortic dilation and remodeling with acute increases in biomechanical forces induced by TAC and these protective effects are independent of alterations in blood pressure.
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Affiliation(s)
- Zhen Zhou
- UT Health Science Cntr at Houston, Houston, TX
| | | | | | - Jiyuan Chen
- UT Health Science Cntr at Houston, Houston, TX
| | - Erin Arthur
- UT Health Science Cntr at Houston, Houston, TX
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8
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Abstract
PURPOSE This work describes the development of a method to measure the variation of apparent diffusion coefficient (ADC) with diffusion time (Δ) in the brachial plexus, as a potential method of probing microstructure. METHODS Diffusion-weighted MRI with body signal suppression was used to highlight the nerves from surrounding tissues, and sequence parameters were optimized for sensitivity to change with diffusion time. A porous media-restricted diffusion model based on the Latour-Mitra equation was fitted to the diffusion time-dependent ADC data from the brachial plexus nerves and cord. RESULTS The ADC was observed to reduce at long diffusion times, confirming that diffusion was restricted in the nerves and cord in healthy subjects. T2 of the nerves was measured to be 80 ± 5 ms, the diffusion coefficient was found to vary from (1.5 ± 0.1) × 10-3 mm2 /s at a diffusion time of 18.3 ms to (1.0 ± 0.2) × 10-3 mm2 /s at a diffusion time of 81.3 ms. CONCLUSION A novel method of probing restricted diffusion in the brachial plexus was developed. Resulting parameters were comparable with values obtained previously on biological systems. Magn Reson Med 79:789-795, 2018. © 2017 International Society for Magnetic Resonance in Medicine.
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Affiliation(s)
- Zaid B Mahbub
- Department of Arts & Sciences, Ahsanullah University of Science & Technology, Dhaka, Bangladesh.,Sir Peter Mansfield Imaging Centre, School of Physics & Astronomy, University of Nottingham, United Kingdom
| | - Andrew M Peters
- Sir Peter Mansfield Imaging Centre, School of Physics & Astronomy, University of Nottingham, United Kingdom
| | - Penny A Gowland
- Sir Peter Mansfield Imaging Centre, School of Physics & Astronomy, University of Nottingham, United Kingdom
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9
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de Weerd-de Jong E, Peters AM, Rahamat-Langendoen JC, Blijlevens NMA. [Current dilemmas on the transmission of hepatitis E virus]. Ned Tijdschr Geneeskd 2017; 161:D1951. [PMID: 29192575] [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] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Immunocompromised patients are especially at risk for developing chronic hepatitis E virus (HEV) infection, which may result in progressive liver disease and cirrhosis. In addition, treatment of chronic HEV infection in these patients often includes dose reduction of immunosuppressive therapy and this may lead to severe flare-ups of the underlying condition or even rejection of transplant material. Therefore prevention of HEV transmission is being more and more recognised as an essential step to stop increasing HEV seroprevalence. The Dutch National Institute for Public Health and the Environment (RIVM) has recently warned immunocompromised patients following haematopoietic stem cell and solid organ transplantations for the risk of infection by HEV through eating of contaminated products from pig meat. Furthermore, the Dutch blood bank recently decided to start screening all blood products for HEV to prevent iatrogenic transmission of HEV. We describe two patients with HEV infection and discuss risk of infection for immunocompromised patients, transmission routes and the importance of prevention of iatrogenic transfusion related transmission.
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10
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Keramida G, Dunford A, Siddique M, Cook GJ, Peters AM. Relationships of body habitus and SUV indices with signal-to-noise ratio of hepatic (18)F-FDG PET. Eur J Radiol 2016; 85:1012-5. [PMID: 27130064 DOI: 10.1016/j.ejrad.2016.02.026] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [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: 02/17/2016] [Accepted: 02/26/2016] [Indexed: 11/15/2022]
Abstract
OBJECTIVE Tissue accumulation of (18)F-FDG is quantified as standardised uptake value (SUV), which may be expressed as the voxel maximum (SUVmax) or mean (SUVmean). SUVmax/SUVmean may be a marker of hepatic steatosis, while the coefficient of variation (CV) of SUV may be a marker of hepatic fat distribution heterogeneity (HFDH). Alternatively, they may reflect low signal-to-noise ratio ('noise') in obese persons in whom hepatic steatosis is common. The study aim was to compare the impact of body size on noise versus SUV and CT density (CTD). METHODS Dynamic PET was performed (30×1min frames) following FDG injection in 60 patients undergoing routine PET/CT. Hepatic FDG clearance was measured using Patlak-Rutland graphical analysis with abdominal aorta as input. Noise was quantified as the standard deviation (SD) of the plot residuals (ignoring the first 2 frames), normalised to the intercept (NRMSD). SUVmax, SUVmean and CTD were measured from 60min whole body PET/CT. CV of SUV and SD of CTD were quantified in 28/60 patients using texture analysis. RESULTS NRMSD correlated with weight (r=0.49; p<0.0001) and BMI (r=0.48; p=0.0001). SUVmax, SUVmean, SUVmax/SUVmean, CV of SUV, CTD, and SD of CTD all correlated strongly with weight and BMI (p<0.0001). However, they correlated weakly with NRMSD, the strongest being SUVmax (r=0.34; p=0.008) and SD of CTD (r=0.42; n=28; p=0.026). CONCLUSIONS Noise is increased in overweight/obese persons but has little effect on SUV indices, CTD and their variabilities. SUVmax/SUVmean and CV of SUV are therefore, to some extent, markers of hepatic steatosis and HFDH, respectively.
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Affiliation(s)
- G Keramida
- Clinical Imaging Sciences Centre, Brighton and Sussex Medical School, Brighton, UK
| | - A Dunford
- Department of Nuclear Medicine, Brighton and Sussex University Hospitals NHS Trust, Brighton, UK
| | - M Siddique
- Imaging Sciences and Biomedical Engineering, King's College, London, UK
| | - G J Cook
- Imaging Sciences and Biomedical Engineering, King's College, London, UK
| | - A M Peters
- Division of Clinical and Laboratory Investigation, Brighton and Sussex Medical School, Brighton, UK.
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11
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Kuang SQ, Medina-Martinez O, Guo DC, Gong L, Regalado ES, Reynolds CL, Boileau C, Jondeau G, Prakash SK, Kwartler CS, Zhu LY, Peters AM, Duan XY, Bamshad MJ, Shendure J, Nickerson DA, Santos-Cortez RL, Dong X, Leal SM, Majesky MW, Swindell EC, Jamrich M, Milewicz DM. FOXE3 mutations predispose to thoracic aortic aneurysms and dissections. J Clin Invest 2016; 126:948-61. [PMID: 26854927 DOI: 10.1172/jci83778] [Citation(s) in RCA: 73] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2015] [Accepted: 12/10/2015] [Indexed: 12/11/2022] Open
Abstract
The ascending thoracic aorta is designed to withstand biomechanical forces from pulsatile blood. Thoracic aortic aneurysms and acute aortic dissections (TAADs) occur as a result of genetically triggered defects in aortic structure and a dysfunctional response to these forces. Here, we describe mutations in the forkhead transcription factor FOXE3 that predispose mutation-bearing individuals to TAAD. We performed exome sequencing of a large family with multiple members with TAADs and identified a rare variant in FOXE3 with an altered amino acid in the DNA-binding domain (p.Asp153His) that segregated with disease in this family. Additional pathogenic FOXE3 variants were identified in unrelated TAAD families. In mice, Foxe3 deficiency reduced smooth muscle cell (SMC) density and impaired SMC differentiation in the ascending aorta. Foxe3 expression was induced in aortic SMCs after transverse aortic constriction, and Foxe3 deficiency increased SMC apoptosis and ascending aortic rupture with increased aortic pressure. These phenotypes were rescued by inhibiting p53 activity, either by administration of a p53 inhibitor (pifithrin-α), or by crossing Foxe3-/- mice with p53-/- mice. Our data demonstrate that FOXE3 mutations lead to a reduced number of aortic SMCs during development and increased SMC apoptosis in the ascending aorta in response to increased biomechanical forces, thus defining an additional molecular pathway that leads to familial thoracic aortic disease.
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MESH Headings
- Adult
- Aortic Dissection/genetics
- Aortic Dissection/metabolism
- Aortic Dissection/pathology
- Animals
- Aorta/metabolism
- Aorta/pathology
- Aortic Aneurysm, Thoracic/genetics
- Aortic Aneurysm, Thoracic/metabolism
- Aortic Aneurysm, Thoracic/pathology
- Apoptosis
- Cells, Cultured
- Cyclin-Dependent Kinase Inhibitor p21/metabolism
- Female
- Forkhead Transcription Factors/genetics
- Gene Expression
- Genetic Association Studies
- Genetic Predisposition to Disease
- Humans
- Male
- Mice, Inbred C57BL
- Mice, Knockout
- Middle Aged
- Muscle, Smooth, Vascular/pathology
- Mutation, Missense
- Myocytes, Smooth Muscle/physiology
- Pedigree
- Tumor Suppressor Protein p53/genetics
- Vascular Remodeling
- Zebrafish
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12
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Keramida G, Hunter J, Dizdarevic S, Peters AM. The appropriate whole-body index on which to base standardized uptake value in 2-deoxy-2-[(18)F]fludeoxyglucose PET. Br J Radiol 2015; 88:20140520. [PMID: 26081445 DOI: 10.1259/bjr.20140520] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
OBJECTIVE Tissue uptake of 2-deoxy-2-fluorine-18 fludeoxyglucose ((18)F-FDG) is routinely quantified as standardized uptake value (SUV), which in general is the fraction (F) of administered activity per millilitre of tissue multiplied by an index of body size, usually weight (W), i.e. F/ml × W = SUV or F/ml = SUV × (1/W). Other indices have been suggested as preferable to W, especially lean body mass (LBM) and body surface area (BSA). The second equation mentioned above shows that the reciprocal of the ideal index should correlate closely with F/ml and give a regression line through the origin. The purpose of this study was to determine which of these three indices best meets these criteria. METHODS Data were evaluated from 49 males and 51 females undergoing routine (18)F-FDG positron emission tomography/CT. A 3 cm diameter region of interest was drawn over the liver and F/ml recorded. LBM and BSA were estimated from height and weight. RESULTS Based on all patients, the reciprocals of the three indices gave similar correlation coefficients with F/ml, but only 1/LBM gave regressions close to the origin. Intercepts were significantly higher for females for 1/W and 1/BSA, consistent with females having more body fat, but there was no significant difference with 1/LBM. CONCLUSION LBM is the best index on which to base SUV because adipose tissue accumulates less (18)F-FDG than other soft tissues. ADVANCES IN KNOWLEDGE The value of this study lies in its use of a novel, more rational approach than previously to confirm that SUV should be based on LBM.
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Affiliation(s)
- G Keramida
- 1 Clinical Imaging Sciences Centre, Brighton Sussex Medical School, University of Sussex, Brighton, UK.,2 Department of Nuclear Medicine, Brighton Sussex University Hospitals NHS Trust, Brighton, UK
| | - J Hunter
- 1 Clinical Imaging Sciences Centre, Brighton Sussex Medical School, University of Sussex, Brighton, UK
| | - S Dizdarevic
- 1 Clinical Imaging Sciences Centre, Brighton Sussex Medical School, University of Sussex, Brighton, UK.,2 Department of Nuclear Medicine, Brighton Sussex University Hospitals NHS Trust, Brighton, UK
| | - A M Peters
- 2 Department of Nuclear Medicine, Brighton Sussex University Hospitals NHS Trust, Brighton, UK
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Cariati M, Bains SK, Grootendorst MR, Suyoi A, Peters AM, Mortimer P, Ellis P, Harries M, Van Hemelrijck M, Purushotham AD. Adjuvant taxanes and the development of breast cancer-related arm lymphoedema. Br J Surg 2015; 102:1071-8. [PMID: 26040263 DOI: 10.1002/bjs.9846] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2014] [Revised: 02/24/2015] [Accepted: 04/07/2015] [Indexed: 11/08/2022]
Abstract
BACKGROUND Despite affecting approximately one-quarter of all patients undergoing axillary lymph node dissection, the pathophysiology of breast cancer-related lymphoedema (BCRL) remains poorly understood. More extensive locoregional treatment and higher body mass index have long been identified as major risk factors. This study aimed to identify risk factors for BCRL with a specific focus on the potential impact of chemotherapy on the risk of BCRL. METHODS This was a retrospective analysis of a cohort of consecutive patients with breast cancer treated at a major London regional teaching hospital between 1 January 2010 and 31 December 2012. All patients had node-positive disease and underwent axillary lymph node dissection. Data regarding tumour-, patient- and treatment-related characteristics were collected prospectively. The diagnosis of BCRL was based on both subjective and objective criteria. Multivariable Cox proportional hazards regression was used to assess the association between treatment and risk of BCRL. RESULTS Some 27.1 per cent of all patients (74 of 273) developed BCRL over the study period. Administration of taxanes showed a strong association with the development of BCRL, as 52 (33.5 per cent) of 155 patients who received taxanes developed BCRL. Multivariable Cox regression analysis demonstrated that patients who received taxanes were nearly three times more likely to develop BCRL than patients who had no chemotherapy (hazard ratio 2.82, 95 per cent c.i. 1.31 to 6.06). No such increase was observed when taxanes were administered in the neoadjuvant setting. CONCLUSION The present findings suggest that adjuvant taxanes play a key role in the development of BCRL after surgery. This may support the use of taxanes in a neoadjuvant rather than adjuvant setting.
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Affiliation(s)
- M Cariati
- Section of Research Oncology, King's College London, London, UK.,Directorate of Haematology and Oncology, Guy's and St Thomas' NHS Foundation Trust, London, UK
| | - S K Bains
- Section of Research Oncology, King's College London, London, UK
| | | | - A Suyoi
- Directorate of Haematology and Oncology, Guy's and St Thomas' NHS Foundation Trust, London, UK
| | - A M Peters
- Department of Nuclear Medicine, Brighton and Sussex University Hospitals NHS Trust, Brighton, UK
| | - P Mortimer
- Department of Clinical Sciences, St George's, University of London, London, UK
| | - P Ellis
- Section of Research Oncology, King's College London, London, UK.,Directorate of Haematology and Oncology, Guy's and St Thomas' NHS Foundation Trust, London, UK
| | - M Harries
- Section of Research Oncology, King's College London, London, UK.,Directorate of Haematology and Oncology, Guy's and St Thomas' NHS Foundation Trust, London, UK
| | - M Van Hemelrijck
- School of Medicine, Cancer Epidemiology Group, Division of Cancer Studies, King's College London, London, UK
| | - A D Purushotham
- Section of Research Oncology, King's College London, London, UK.,Directorate of Haematology and Oncology, Guy's and St Thomas' NHS Foundation Trust, London, UK
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Stuttle AW, Klosok J, Peters AM, Henderson BL, Lavender JP. Imaging venous thrombosis with indium-111 labelled P256 Fab'. Curr Stud Hematol Blood Transfus 2015:200-4. [PMID: 1954768 DOI: 10.1159/000419362] [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] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
- A W Stuttle
- Department of Medical Physics, Royal Postgraduate Medical School, Hammersmith Hospital, London, UK
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15
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Peters AM, Gunasekera RD, Lavender JP, Myers MJ, Gordon I, Ash JM, Gilday DL. Noninvasive measurement of renal blood flow using DTPA. Contrib Nephrol 2015; 56:26-30. [PMID: 3608498 DOI: 10.1159/000413776] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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16
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Bains SK, Peters AM, Zammit C, Ryan N, Ballinger J, Glass DM, Allen S, Stanton AWB, Mortimer PS, Purushotham AD. Global abnormalities in lymphatic function following systemic therapy in patients with breast cancer. Br J Surg 2015; 102:534-40. [DOI: 10.1002/bjs.9766] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2014] [Revised: 08/20/2014] [Accepted: 12/04/2014] [Indexed: 11/07/2022]
Abstract
Abstract
Background
Breast cancer-related lymphoedema (BCRL) is a result of interaction between several pathophysiological processes, and is not simply a ‘stopcock’ effect resulting from removal of axillary lymph nodes. The aim of this study was to test the hypothesis that there is a constitutional ‘global’ lymphatic dysfunction in patients who develop BCRL.
Methods
Lower-limb lymphoscintigraphy was performed in 30 women who had undergone axillary lymph node dissection at least 3 years previously, of whom 15 had BCRL and 15 did not. No patient had any clinical abnormality of the lower limb. The control group comprised 24 women with no history of cancer or lower-limb lymphoedema. 99mTc-Nanocoll was injected subcutaneously into the first webspace of each foot, followed by whole-body imaging. Scans were reported as abnormal if there was delay in lymph transport or rerouting through skin or deep system. Quantification was expressed as the percentage injected activity accumulating in ilioinguinal nodes.
Results
Mean(s.d.) ilioinguinal nodal accumulation at 150 min was significantly lower in women with BCRL than in those without (2·7(2·5) versus 5·9(4·8) per cent respectively; P = 0·006). Abnormal findings on lower-limb lymphoscintigraphy were observed in 17 of the 30 patients: ten of the 15 women who had BCRL and seven of the 15 who did not. None of the 24 control subjects had abnormal scan findings.
Conclusion
Women with BCRL had reduced lower-limb lymph drainage, supporting the hypothesis of a predisposition to BCRL. A surprisingly high proportion of patients with breast cancer also demonstrated lymphatic dysfunction, despite clinically normal lower limbs. Possible explanations could be a systemic effect of breast cancer or its treatment, or an unidentified association between breast cancer and lymphatic dysfunction. Registration number: ISRCTN84866416 (http://www.isrctn.com).
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Affiliation(s)
- S K Bains
- Division of Cancer Studies, King's College London, St George's, University of London, London, UK
- Department of Breast Surgery, St George's, University of London, London, UK
| | - A M Peters
- Department of Nuclear Medicine, Brighton and Sussex University Hospitals NHS Trust, Brighton, UK
| | - C Zammit
- Department of Breast Surgery, Brighton and Sussex University Hospitals NHS Trust, Brighton, UK
| | - N Ryan
- Department of Nuclear Medicine, Brighton and Sussex University Hospitals NHS Trust, Brighton, UK
| | - J Ballinger
- Department of Nuclear Medicine, Guy's and St Thomas' NHS Foundation Trust, St George's, University of London, London, UK
| | - D M Glass
- Department of Molecular Imaging Centre, Harley Street Clinic, St George's, University of London, London, UK
| | - S Allen
- Department of Nuclear Medicine, Guy's and St Thomas' NHS Foundation Trust, St George's, University of London, London, UK
| | - A W B Stanton
- Department of Clinical Sciences, St George's, University of London, London, UK
| | - P S Mortimer
- Department of Clinical Sciences, St George's, University of London, London, UK
| | - A D Purushotham
- Division of Cancer Studies, King's College London, St George's, University of London, London, UK
- Department of Breast Surgery, St George's, University of London, London, UK
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Bains SK, Stanton AWB, Cintolesi V, Ballinger J, Allen S, Zammit C, Levick JR, Mortimer PS, Peters AM, Purushotham AD. A constitutional predisposition to breast cancer-related lymphoedema and effect of axillary lymph node surgery on forearm muscle lymph flow. Breast 2014; 24:68-74. [PMID: 25491189 DOI: 10.1016/j.breast.2014.11.010] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2014] [Revised: 08/13/2014] [Accepted: 11/19/2014] [Indexed: 11/24/2022] Open
Abstract
AIM The aims of this prospective study were (a) to examine the relationship between pre-operative muscle lymph flow and the predisposition to BCRL in women treated by axillary nodal surgery for breast cancer; and (b) to test the 'stopcock' hypothesis that axillary lymph node surgery impairs forearm lymph flow in the short term. METHODS (99m)Tc-nanocoll was injected intramuscularly into both forearms of women undergoing surgery for breast cancer. Lymphatic clearance rate constant, k, representing lymph flow per unit interstitial fluid volume, was measured as the fractional disappearance rate of radioactivity from the depot site by gamma camera imaging. Axillary lymph node activity was calculated as percentage injected activity. BCRL was assessed by clinical examination and upper limb perometry. RESULTS Of 38 pre-operative women, 33 attended at 8 ± 6 weeks post-operatively and 31 at 58 ± 9 weeks post-operatively. Seven patients (18%) developed BCRL. Prior to surgery the BCRL-destined patients had a higher mean k (0.0962 ± 0.034%/min) than non-BCRL patients (0.0830 ± 0.019%/min) (p = 0.10, unpaired t test). Post-operative k values were not significantly different from pre-operative, in either the ipsilateral (operated) or contralateral limb. Also, post-operative k values did not differ significantly between both upper limbs. Furthermore, there was no significant difference between pre- and post-operative axillary activity. CONCLUSION Patients who develop BCRL have high lymph flow pre-surgery, which may predispose them to lymphatic overload and failure. Axillary lymph node surgery has no early, measurable effect on forearm muscle lymph flow despite surgical disruption of routes of lymph drainage.
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Affiliation(s)
- S K Bains
- Division of Cancer Studies, King's College London, United Kingdom; Guy's & St Thomas' NHS Foundation Trust, United Kingdom
| | - A W B Stanton
- Clinical Sciences, St George's, University of London, United Kingdom
| | - V Cintolesi
- Clinical Sciences, St George's, University of London, United Kingdom
| | - J Ballinger
- Guy's & St Thomas' NHS Foundation Trust, United Kingdom
| | - S Allen
- Guy's & St Thomas' NHS Foundation Trust, United Kingdom
| | - C Zammit
- Department of Breast Surgery, Brighton and Sussex University Hospitals NHS Trust, United Kingdom
| | - J R Levick
- Clinical Sciences, St George's, University of London, United Kingdom
| | - P S Mortimer
- Clinical Sciences, St George's, University of London, United Kingdom
| | - A M Peters
- Department of Nuclear Medicine, Brighton and Sussex University Hospitals NHS Trust, United Kingdom
| | - A D Purushotham
- Division of Cancer Studies, King's College London, United Kingdom; Guy's & St Thomas' NHS Foundation Trust, United Kingdom.
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Finch NC, Heiene R, Elliott J, Syme HM, Peters AM. Determination of extracellular fluid volume in healthy and azotemic cats. J Vet Intern Med 2014; 29:35-42. [PMID: 25406506 PMCID: PMC4858083 DOI: 10.1111/jvim.12506] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2014] [Revised: 07/22/2014] [Accepted: 10/21/2014] [Indexed: 11/27/2022] Open
Abstract
BACKGROUND Methods for determining extracellular fluid volume (ECFV) are important clinically for cats. Bromide dilution has been studied in cats to estimate ECFV. Markers of GFR also distribute in ECFV and can be used for its measurement. HYPOTHESIS/OBJECTIVES The primary objective was to develop a method of determining ECFV from iohexol clearance in cats and evaluate agreement with that determined using bromide dilution. Additional objectives were to compare ECFV between azotemic and nonazotemic cats and evaluate appropriate methods of standardizing ECFV. ANIMALS Client-owned cats with varying renal function. METHODS Validation of ECFV determined from slope-intercept iohexol clearance was performed in 18 healthy nonazotemic cats. ECFV was then determined using the validated method and bromide dilution and agreement assessed. Appropriateness of standardization to body weight (BW) and body surface area (BSA) was evaluated. RESULTS Extracellular fluid volume determined from slope-intercept iohexol clearance and bromide dilution was 0.84 ± 0.32 L and 0.85 ± 0.19 L (mean ± SD), respectively. There were wide limits of agreement between the methods (-0.58 to 0.54 L) and therefore, agreement was considered to be poor. ECFV did not differ significantly between azotemic and nonazotemic cats (P = .177). BSA was found to be the best method for standardizing ECFV measurement in cats. CONCLUSIONS AND CLINICAL IMPORTANCE This study developed a method for determining ECFV from slope-intercept iohexol clearance which provides simultaneous assessment of renal function and an estimate of ECFV. ECFV does not differ between azotemic and nonazotemic cats, which suggests fluid volume loss or overload is not an important clinical feature in cats with mild chronic kidney disease.
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Affiliation(s)
- N C Finch
- Royal Veterinary College, London, UK
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19
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Ding Y, Ward WOC, Wästerlid T, Gowland PA, Peters AM, Yang J, Nakagawa S, Bai L. Three-dimensional vessel segmentation using a novel combinatory filter framework. Phys Med Biol 2014; 59:7013-29. [DOI: 10.1088/0031-9155/59/22/7013] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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20
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Kuang SQ, Geng L, Prakash SK, Cao JM, Guo S, Villamizar C, Kwartler CS, Peters AM, Brasier AR, Milewicz DM. Aortic remodeling after transverse aortic constriction in mice is attenuated with AT1 receptor blockade. Arterioscler Thromb Vasc Biol 2013; 33:2172-9. [PMID: 23868934 DOI: 10.1161/atvbaha.113.301624] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
OBJECTIVE Although hypertension is the most common risk factor for thoracic aortic diseases, it is not understood how increased pressures on the ascending aorta lead to aortic aneurysms. We investigated the role of angiotensin II type 1 receptor activation in ascending aortic remodeling in response to increased biomechanical forces using a transverse aortic constriction (TAC) mouse model. APPROACH AND RESULTS Two weeks after TAC, the increased biomechanical pressures led to ascending aortic dilatation and thickening of the medial and adventitial layers of the aorta. There was significant adventitial hyperplasia and inflammatory responses in TAC ascending aortas were accompanied by increased adventitial collagen, elevated inflammatory and proliferative markers, and increased cell density attributable to accumulation of myofibroblasts and macrophages. Treatment with losartan significantly blocked TAC-induced vascular inflammation and macrophage accumulation. However, losartan only partially prevented TAC-induced adventitial hyperplasia, collagen accumulation, and ascending aortic dilatation. Increased Tgfb2 expression and phosphorylated-Smad2 staining in the medial layer of TAC ascending aortas were effectively blocked with losartan. In contrast, the increased Tgfb1 expression and adventitial phospho-Smad2 staining were only partially attenuated by losartan. In addition, losartan significantly blocked extracellular signal-regulated kinase activation and reactive oxygen species production in the TAC ascending aorta. CONCLUSIONS Inhibition of the angiotensin II type 1 receptor using losartan significantly attenuated the vascular remodeling associated with TAC but did not completely block the increased transforming growth factor-β1 expression, adventitial Smad2 signaling, and collagen accumulation. These results help to delineate the aortic transforming growth factor-β signaling that is dependent and independent of the angiotensin II type 1 receptor after TAC.
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Affiliation(s)
- Shao-Qing Kuang
- Department of Internal Medicine, University of Texas Health Science Center at Houston, University of Texas Medical Branch, Houston, TX 77030, USA
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Acharya S, Peters AM, Norton AS, Murdoch GK, Hill RA. Change in Nox4 expression is accompanied by changes in myogenic marker expression in differentiating C2C12 myoblasts. Pflugers Arch 2013; 465:1181-96. [PMID: 23503725 DOI: 10.1007/s00424-013-1241-0] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2012] [Revised: 01/10/2013] [Accepted: 02/04/2013] [Indexed: 01/10/2023]
Abstract
Myoblast differentiation is mediated by a cascade of changes in gene expression including transcription factors such as myogenin. Subsequent to myoblast differentiation, there is an increase in expression of the transmembrane protein NADPH oxidase (Nox). Nox is one of the primary factors for the generation of reactive oxygen species (ROS) in myogenic (C2C12) cells. Recently, ROS have been shown to be important regulators of several intracellular signaling pathways, and the full extent of their regulatory roles is yet to be discovered. In the present study, qRT PCR analysis demonstrated that Nox4 isoform is primarily expressed in differentiating C2C12 cells and contributes to the generation of ROS in C2C12 myoblast during differentiation. Over-expression and silencing of Nox4 expression during myoblast differentiation was accompanied by a reduction in intracellular ROS concentrations and an alteration in the expression patterns of Myf5, Pax7, MyoD1, and myogenin. This modulation was found to be associated with ERK1/2 phosphorylation. In both over-expression and reduced expression of Nox4, we found significant reductions in ERK1/2 phosphorylation. This indicates that cellular differentiation may be affected by Nox4-mediated endogenous ROS generation. These data suggest a new opportunity to study the temporal expression of Nox4 in the generation of ROS accompanying changes in myogenic differentiation.
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Affiliation(s)
- S Acharya
- Department of Animal and Veterinary Science, University of Idaho, Moscow, ID 83844, USA
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22
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Modi BN, Brown JLE, Kumar G, Driver RM, Kelion AD, Peters AM, Fowler JC. A qualitative and quantitative assessment of the impact of three processing algorithms with halving of study count statistics in myocardial perfusion imaging: filtered backprojection, maximal likelihood expectation maximisation and ordered subset expectation maximisation with resolution recovery. J Nucl Cardiol 2012; 19:945-57. [PMID: 22753073 DOI: 10.1007/s12350-012-9575-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2011] [Accepted: 04/26/2012] [Indexed: 11/28/2022]
Abstract
INTRODUCTION Ordered subset expectation maximisation with depth-dependent resolution recovery (OSEM-RR) is a processing algorithm reported to improve images with halved tracer activity in myocardial perfusion scintigraphy (MPS) compared to filtered backprojection (FBP) using conventional activities. OSEM-RR has not yet been compared with maximal likelihood expectation maximisation (MLEM). METHODS 39 patients undergoing MPS and two anthropomorphic phantoms (one with, one without an inferior wall insert) had full-time (FT) and half-time (HT) SPECT datasets acquired simultaneously and processed by FBP, MLEM and OSEM-RR. Two experienced reporters scored images of all clinical studies (n=234) for conspicuity of a perfusion defect, with results being compared using Wilcoxon paired and Kappa tests. A quantitative assessment based on mean segmental pixel counts taken from numbers automatically displayed over the 20 segments of Cedars Sinai Autoquant QPS image were compared using Pearson's correlation and Bland Altman analysis. RESULTS A small but consistent superior concurrence between FT and HT datasets for OSEM-RR compared to FBP and MLEM was observed for both qualitative and quantitative analyses. OSEM-RR resulted in better definition of the inferior wall defect on the phantom study. CONCLUSION OSEM-RR appears superior to both FBP and MLEM in terms of handling reduced count statistics.
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Affiliation(s)
- B N Modi
- Nuclear Medicine Department, Luton & Dunstable NHS Foundation Trust, Luton, UK
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23
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Lotfipour AK, Wharton S, Schwarz ST, Gontu V, Schäfer A, Peters AM, Bowtell RW, Auer DP, Gowland PA, Bajaj NP. High resolution magnetic susceptibility mapping of the substantia nigra in Parkinson's disease. J Magn Reson Imaging 2011; 35:48-55. [DOI: 10.1002/jmri.22752] [Citation(s) in RCA: 166] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2011] [Accepted: 07/21/2011] [Indexed: 01/06/2023] Open
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Abstract
BACKGROUND In adults, dosages of some anaesthetic agents are based on lean body mass (LBM) rather than body weight. Our aim was to derive an equation for estimating LBM in children. METHODS Patients comprised three groups: prospective kidney transplant donors from two separate centres (centres 1 and 3) and children referred to a further centre (centre 2) for the routine clinical measurement of glomerular filtration rate (GFR). GFR and extracellular fluid volume (ECV) were measured using Cr-51-EDTA. LBM was directly estimated (eLBM) in adults using an equation based on height and weight. ECV in children was estimated (eECV) from another equation based on height and weight, converted to eLBM using the relationship between eLBM and ECV determined in the adults from centre 1 and then compared with adult data from centre 3. RESULTS In children, the ratio of eECV to ECV was 1.04 (SD 0.18). In centre 1, eLBM (kg) was 3.81 (SD 0.55) times greater than ECV (litres) in men (n=50) and 3.77 (0.77) times greater in women (n=51). eLBM in children was therefore derived by multiplying eECV by 3.8. In children, eLBM showed a close linear correlation with measured ECV (eLBM=3.50ECV+2.0; R(2)=0.857), similar to adults (eLBM=2.82ECV+14.5; R(2)=0.582). In all groups, eLBM/weight correlated inversely with weight. CONCLUSIONS In terms of the relationships between eLBM, ECV, and weight, children are similar to adults. Therefore, drug dosage in children should also be based on eLBM rather than weight.
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Affiliation(s)
- A M Peters
- Department of Nuclear Medicine, Harley St Clinic, London, UK.
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Abstract
Primary intrinsic and/or acquired multidrug resistance (MDR) is the main obstacle to successful cancer treatment. Functional molecular imaging of MDR in cancer using single photon or positron emitters may be helpful to identify multidrug-resistant tumours and predict not only those patients who are resistant to treatment, with a clinically unfavourable prognosis, but also those who are susceptible to the development of drug toxicity or even certain tumours . Variations in the mdr1 gene product may directly affect the therapeutic effectiveness, and single nucleotide polymorphisms for the mdr1 gene may be associated with altered oral bioavailability of MDR1 substrates, drug resistance, and a susceptibility to some human diseases. The challenge of translating the concept of MDR modulation in vivo involves a complex cellular interplay between both malignant and normal cells. Integration and correlation of functional single photon emission tomography or positron emission tomography imaging findings with mdr1 genotype and clinical data may contribute to efficient management by selecting cancer patients with the appropriate molecular phenotype for maximal individual therapeutic benefit, as well as those who are non-responders. This review describes a role for functional imaging of classical mechanisms of MDR with an emphasis on readily available [99mTc]MIBI scintigraphy. MIBI scintigraphy has been shown to be a non-invasive cost-effective in vivo assay of ATP-binding cassette transporters associated with MDR in cancer, including P-glycoprotein, multidrug-resistant protein 1 and breast cancer resistant protein. New imaging agents for molecular targets such as vascular endothelial growth factor and HER2 receptors, may potentially be combined with MDR imaging substrates to more accurately predict the therapeutic response to anticancer drugs, guiding individualised treatment while minimising the economic health costs of ineffective therapy in an era of personalised medicine.
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Affiliation(s)
- S Dizdarevic
- Department of Nuclear Medicine, Brighton and Sussex University Hospitals NHS Trust, Brighton, UK.
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26
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Bennett Britton TM, Wallace SML, Wilkinson IB, Mortimer PS, Peters AM, Purushotham AD. Sympathetic nerve damage as a potential cause of lymphoedema after axillary dissection for breast cancer. Br J Surg 2009; 96:865-9. [PMID: 19591159 DOI: 10.1002/bjs.6660] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
BACKGROUND The physiological disturbances leading to lymphoedema after breast cancer surgery are poorly understood. Damage to sympathetic nerves during axillary lymph node dissection (ALND), leading to increased capillary fluid filtration, was investigated as a possible contributory factor. METHODS The integrity of the upper limb sympathetic nervous system was tested in 36 patients before, and 3 and 12 months after ALND. Forearm vascular resistance (FVR), calculated from forearm blood flow and mean systemic arterial pressure, was measured before and after exposure to lower-body negative pressure. Forearm venous compliance was measured using (99m)Tc-labelled autologous erythrocytes and radionuclide plethysmography before and after cold water immersion of the feet. RESULTS There were clear changes in FVR and venous compliance in response to sympathetic stimulation but no differences attributable to surgery or between the nine patients who developed lymphoedema and the 27 who did not; nor were there differences between the two arms. There was a trend towards lower preoperative FVR in patients who developed lymphoedema. CONCLUSION Lymphoedema is not the result of sympathetic nerve damage sustained during ALND. Preoperative FVR may help predict who will get lymphoedema following this surgery.
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Affiliation(s)
- T M Bennett Britton
- Department of Research Oncology, King's College London and Guy's and St Thomas' NHS Foundation Trust, Bermondsey Wing, Guy's Hospital, London, UK
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Peters AM, Pirat C, Sbragaglia M, Borkent BM, Wessling M, Lohse D, Lammertink RGH. Cassie-Baxter to Wenzel state wetting transition: scaling of the front velocity. Eur Phys J E Soft Matter 2009; 29:391-397. [PMID: 19669178 DOI: 10.1140/epje/i2009-10489-3] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2009] [Accepted: 07/08/2009] [Indexed: 05/28/2023]
Abstract
We experimentally study the dynamics of water in the Cassie-Baxter state to Wenzel state transition on surfaces decorated with assemblies of micrometer-size square pillars arranged on a square lattice. The transition on the micro-patterned superhydrophobic polymer surfaces is followed with a high-speed camera. Detailed analysis of the movement of the liquid during this transition reveals the wetting front velocity dependence on the geometry and material properties. We show that a decrease in gap size as well as an increase in pillar height and intrinsic material hydrophobicity result in a lower front velocity. Scaling arguments based on balancing surface forces and viscous dissipation allow us to derive a relation with which we can rescale all experimentally measured front velocities, obtained for various pattern geometries and materials, on one single curve.
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Affiliation(s)
- A M Peters
- Membrane Technology Group, Faculty of Science and Technology, Mesa+ Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands
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Peters AM, Ciapryna MB, Bowles PF, Glass DM. Obesity does not accelerate the decline in glomerular filtration rate associated with advancing age. Int J Obes (Lond) 2009; 33:379-81. [PMID: 19188924 DOI: 10.1038/ijo.2009.6] [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] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Obesity has been suggested as a risk factor for chronic kidney disease. However, it has also been suggested that the association between obesity and impaired glomerular filtration rate (GFR) arises from the invalid use of body surface area (BSA) for scaling. This study assesses the effect of obesity on GFR by comparing the age-dependent decline in obese (body mass index (BMI) >30 kg/m(2); n=149) and non-obese patients (n=589), aged >30 years, referred for measurement of GFR (Cr-51-EDTA and three blood samples). GFR was scaled to a BSA of 1.73 m(2) (GFR/BSA) and extracellular fluid volume of 13 l (GFR/ECV), both corrected for the one-compartment assumption. When non-obese patients were categorized into 10-year age brackets (from 31 to >70), GFR/BSA and GFR/ECV declined from 92 ml per min per 1.73 m(2) and 95 ml per min per 13 l, respectively, at 31-40 years to 58 and 59 at >70. The declines in obese patients were similar with corresponding values of 88 ml per min per 1.73 m(2) and 97 ml per min per 13 l at 31-40 and 57 and 59 at >70 years. Linear regression analysis of non-categorized data from age 40 years showed rates of decline slightly slower in the obese (0.82 vs 0.95 ml per min per 1.73 m(2) per year and 0.87 vs 1.02 ml per min per 13 l per year). No effect of obesity on renal function was shown. Scaling to BSA did not distort the results.
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Affiliation(s)
- A M Peters
- Nuclear Medicine, Brighton and Sussex Medical School, Eastern Road, Brighton, UK.
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29
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Affiliation(s)
- P Ruparelia
- Department of Medicine, University of Cambridge School of Clinical Medicine, Addenbrooke's Hospital, Cambridge, UK
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30
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Bird NJ, Peters C, Michell AR, Peters AM. Reliability of the MDRD method for estimating glomerular filtration rate in relation to gender, body mass index and extracellular fluid volume. Eur J Clin Invest 2008; 38:486-93. [PMID: 18578690 DOI: 10.1111/j.1365-2362.2008.01960.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
BACKGROUND The accuracy of estimating glomerular filtration rate from plasma creatinine (eGFR) has been questioned but it is unclear how much covert error in several reference methods that have been used has contributed to this perceived inaccuracy. The aim of the study was to evaluate eGFR in comparison with a second 'gold standard' to test the performance of the primary gold standard and to examine the influence of patient demographics (age, body mass index (BMI), extracellular fluid volume (ECV) and gender). DESIGN Non-fasting multisample GFR and ECV were measured in 80 subjects simultaneously and independently with Cr-51-EDTA (GFR(EDTA)) and iohexol (GFR(iohexol)). Percentage bias and imprecision in the prediction of, and disagreement with, GFR(EDTA) were compared between eGFR and GFR(iohexol). Another simplified method for measuring GFR, the slope-only method ((SO)GFR), was also evaluated against multisample GFR (measured with the opposing indicator). Accuracies were assessed in all subjects and across age, BMI and ECV boundaries of 65 y, 29 kg m(-2) and 14 L. RESULTS eGFR was less precise than GFR(iohexol) (imprecisions of 22.3% and 12.9%; P < 0.01). The precision of (SO)GFR was intermediate between eGFR and GFR(iohexol). Both GFR(iohexol) and eGFR were less precise in the elderly, the obese and men, but minimally influenced by ECV. (SO)GFR was minimally influenced by subject demographics. CONCLUSION Although eGFR does not predict GFR (based on a primary gold standard) as accurately as a second gold standard, a significant component of its poor performance is the result of inaccuracy in the primary gold standard. (SO)GFR measured with Cr-51-EDTA is superior to eGFR.
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Affiliation(s)
- N J Bird
- Department of Nuclear Medicine, Addenbrooke's Hospital, Cambridge, UK
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31
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Brookes MJ, Vrba J, Robinson SE, Stevenson CM, Peters AM, Barnes GR, Hillebrand A, Morris PG. Optimising experimental design for MEG beamformer imaging. Neuroimage 2007; 39:1788-802. [PMID: 18155612 DOI: 10.1016/j.neuroimage.2007.09.050] [Citation(s) in RCA: 195] [Impact Index Per Article: 11.5] [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] [Received: 03/26/2007] [Revised: 09/19/2007] [Accepted: 09/22/2007] [Indexed: 11/17/2022] Open
Abstract
In recent years, the use of beamformers for source localisation has significantly improved the spatial accuracy of magnetoencephalography. In this paper, we examine techniques by which to optimise experimental design, and ensure that the application of beamformers yields accurate results. We show that variation in the experimental duration, or variation in the bandwidth of a signal of interest, can significantly affect the accuracy of a beamformer reconstruction of source power. Specifically, power will usually be underestimated if covariance windows are made too short, or bandwidths too narrow. The accuracy of spatial localisation may also be reduced. We conclude that for optimum accuracy, experimenters should aim to collect as much data as possible, and use a bandwidth spanning the entire frequency distribution of the signal of interest. This minimises distortion to reconstructed source images, time courses and power estimation. In the case where experimental duration is short, and small covariance windows are therefore used, we show that accurate power estimation can be achieved by matrix regularisation. However, large amounts of regularisation cause a loss in the spatial resolution of the MEG beamformer, hence regularisation should be used carefully, particularly if multiple sources in close proximity are expected.
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Affiliation(s)
- Matthew J Brookes
- Sir Peter Mansfield Magnetic Resonance Centre, School of Physics and Astronomy, University of Nottingham, University Park, Nottingham, UK.
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Meissner PE, Jappe U, Niemeyer CM, Peters AM, Kulozik A, Zilow EP. Pyoderma Gangraenosum, a Rare, but Potentially Fatal Complication in Paediatric Oncology Patients. Klin Padiatr 2007; 219:296-9. [PMID: 16865656 DOI: 10.1055/s-2006-933544] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Pyoderma gangraenosum (PG) is a serious chronic, ulcerative skin disorder afflicting both adults and children. As PG is often associated with systemic diseases (>50%) such as inflammatory bowel disease, rheumatoid arthritis or haematological disorders, it requires a multidisciplinary approach. This disorder is not commonly reported in paediatrics; therefore children with PG represent a particularly difficult diagnostic challenge. Clinical diagnosis is often delayed and PG is only considered after eliminating other causes of cutaneous ulcers. We report a 4-year-old boy with secondary myelodysplastic syndrome following treatment for acute lymphoblastic leukaemia who presented with a massive inflammatory, ulcerative proliferation of the lower lip which was diagnosed as PG. We have reviewed the literature with reference to diagnostic criteria and treatment options of this disorder that is particularly rare in childhood.
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Affiliation(s)
- P E Meissner
- Department of Neonatology, Heidelberg University, Germany.
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Chapman GE, Ballinger JR, Norton MJ, Parry-Jones DR, Beharry NA, Cousins C, Dash CH, Peters AM. The clearance kinetics of autologous RhD-positive erythrocytes coated ex vivo with novel recombinant and monoclonal anti-D antibodies. Clin Exp Immunol 2007; 150:30-41. [PMID: 17680827 PMCID: PMC2219283 DOI: 10.1111/j.1365-2249.2007.03458.x] [Citation(s) in RCA: 6] [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: 11/27/2022] Open
Abstract
Anti-D is given routinely to pregnant RhD-negative women to prevent haemolytic disease of the fetus and newborn. To overcome the potential drawbacks associated with plasma-derived products, monoclonal and recombinant forms of anti-D have been developed. The ability of two such antibodies, BRAD-3/5 monoclonal anti-D IgG (MAD) and rBRAD-3/5 recombinant anti-D IgG (RAD), to clear RhD-positive erythrocytes from the circulation was compared using a dual radiolabelling technique. Six RhD-positive males received autologous erythrocytes radiolabelled with (99m)Tc and (51)Cr and coated ex vivo with MAD and RAD. Blood samples were collected up to 1 h following intravenous injection, and percentage dose of radioactivity in the samples determined. Three different levels of coating were used on three separate occasions. No significant differences between MAD and RAD were observed in the initial clearance rate constant at any dose level. The log[activity]-time clearance plots were curved, showing a reduction in the clearance rate constant with time. This reduction was more marked for RAD than for MAD. The results support a dynamic model for the clearance of antibody-coated erythrocytes that may have wider relevance for the therapeutic use of antibodies.
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Affiliation(s)
- G E Chapman
- Bio Products Laboratory, Elstree, Hertfordshire, UK
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34
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Sumner P, Nachev P, Morris P, Peters AM, Jackson SR, Kennard C, Husain M. Human medial frontal cortex mediates unconscious inhibition of voluntary action. Neuron 2007; 54:697-711. [PMID: 17553420 PMCID: PMC1890004 DOI: 10.1016/j.neuron.2007.05.016] [Citation(s) in RCA: 224] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2006] [Revised: 03/09/2007] [Accepted: 05/04/2007] [Indexed: 11/27/2022]
Abstract
Within the medial frontal cortex, the supplementary eye field (SEF), supplementary motor area (SMA), and pre-SMA have been implicated in the control of voluntary action, especially during motor sequences or tasks involving rapid choices between competing response plans. However, the precise roles of these areas remain controversial. Here, we study two extremely rare patients with microlesions of the SEF and SMA to demonstrate that these areas are critically involved in unconscious and involuntary motor control. We employed masked-prime stimuli that evoked automatic inhibition in healthy people and control patients with lateral premotor or pre-SMA damage. In contrast, our SEF/SMA patients showed a complete reversal of the normal inhibitory effect--ocular or manual--corresponding to the functional subregion lesioned. These findings imply that the SEF and SMA mediate automatic effector-specific suppression of motor plans. This automatic mechanism may contribute to the participation of these areas in the voluntary control of action.
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Affiliation(s)
- Petroc Sumner
- School of Psychology, Cardiff University, Tower Building, Park Place, Cardiff CF10 3AT, UK
- Corresponding author
| | - Parashkev Nachev
- Division of Neuroscience, Faculty of Medicine, Imperial College London, St Dunstan's Road, London W6 8RP, UK
| | - Peter Morris
- Magnetic Resonance Centre, School of Physics and Astronomy, University of Nottingham, University Park, Nottingham NG7 2RD, UK
| | - Andrew M. Peters
- Magnetic Resonance Centre, School of Physics and Astronomy, University of Nottingham, University Park, Nottingham NG7 2RD, UK
| | - Stephen R. Jackson
- School of Psychology, University of Nottingham, University Park, Nottingham NG7 2RD, UK
| | - Christopher Kennard
- Division of Neuroscience, Faculty of Medicine, Imperial College London, St Dunstan's Road, London W6 8RP, UK
| | - Masud Husain
- Institute of Neurology and Institute of Cognitive Neuroscience, University College London, 17 Queen Square, London WC1N 3AR, UK
- Corresponding author
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Peters AM, Brookes MJ, Hoogenraad FG, Gowland PA, Francis ST, Morris PG, Bowtell R. T2* measurements in human brain at 1.5, 3 and 7 T. Magn Reson Imaging 2007; 25:748-53. [PMID: 17459640 DOI: 10.1016/j.mri.2007.02.014] [Citation(s) in RCA: 166] [Impact Index Per Article: 9.8] [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] [Received: 01/11/2007] [Indexed: 12/30/2022]
Abstract
Measurements have been carried out in six subjects at magnetic fields of 1.5, 3 and 7 T, with the aim of characterizing the variation of T2* with field strength in human brain. Accurate measurement of T2* in the presence of macroscopic magnetic field inhomogeneity is problematic due to signal decay resulting from through-slice dephasing. The approach employed here allowed the signal decay due to through-slice dephasing to be characterized and removed from data, thus facilitating an accurate measurement of T2* even at ultrahigh field. Using double inversion recovery turbo spin-echo images for tissue classification, an analysis of T2* relaxation times in cortical grey matter and white matter was carried out, along with an evaluation of the variation of T2* with field strength in the caudate nucleus and putamen. The results show an approximately linear increase in relaxation rate R2* with field strength for all tissues, leading to a greater range of relaxation times across tissue types at 7 T that can be exploited in high-resolution T2*-weighted imaging.
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Affiliation(s)
- Andrew M Peters
- Sir Peter Mansfield Magnetic Resonance Center, School of Physics and Astronomy, University of Nottingham, NG7 2RD Nottingham, UK
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36
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Modi S, Stanton AWB, Svensson WE, Peters AM, Mortimer PS, Levick JR. Human lymphatic pumping measured in healthy and lymphoedematous arms by lymphatic congestion lymphoscintigraphy. J Physiol 2007; 583:271-85. [PMID: 17569739 PMCID: PMC2277237 DOI: 10.1113/jphysiol.2007.130401] [Citation(s) in RCA: 114] [Impact Index Per Article: 6.7] [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: 01/13/2023] Open
Abstract
Axillary surgery for breast cancer partially obstructs lymph outflow from the arm, chronically raising the lymphatic smooth muscle afterload. This may lead to pump failure, as in hypertensive cardiac failure, and could explain features of breast cancer treatment-related lymphoedema (BCRL) such as its delayed onset. A new method was developed to measure human lymphatic contractility non-invasively and test the hypothesis of contractile impairment. 99mTc-human IgG (Tc-HIG), injected into the hand dermis, drained into the arm lymphatic system which was imaged using a gamma-camera. Lymph transit time from hand to axilla, ttransit, was 9.6+/-7.2 min (mean+/-s.d.) (velocity 8.9 cm min(-1)) in seven normal subjects. To assess lymphatic contractility, a sphygmomanometer cuff around the upper arm was inflated to 60 mmHg (Pcuff) before 99mTc-HIG injection and maintained for>>ttransit. When Pcuff exceeded the maximum pressure generated by the lymphatic pump (Ppump), radiolabelled lymph was held up at the distal cuff border. Pcuff was then lowered in 10 mmHg steps until 99mTc-HIG began to flow under the cuff to the axilla, indicating Ppump>or=Pcuff. In 16 normal subjects Ppump was 39+/-14 mmHg. Ppump was 38% lower in 16 women with BCRL, namely 24+/-19 mmHg (P=0.014, Student's unpaired t test), and correlated negatively with the degree of swelling (12-56%). Blood radiolabel accumulation proved an unreliable measure of lymphatic pump function. Lymphatic congestion lymphoscintigraphy thus provided a quantitative measure of human lymphatic contractility without surgical cut-down, and the results supported the hypothesis of lymphatic pump failure in BCRL.
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Affiliation(s)
- S Modi
- Cardiac and Vascular Sciences, St George's Hospital Medical School, University of London, Cranmer Terrace, London SW17 0RE, UK
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37
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O'Mahony S, Britton TMB, Solanki CK, Ballinger JR, Pain SJ, Mortimer PS, Purushotham AD, Peters AM. Lymphatic transfer studies with immunoglobulin scintigraphy after axillary surgery. Eur J Surg Oncol 2007; 33:1052-60. [PMID: 17499475 DOI: 10.1016/j.ejso.2007.03.012] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [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] [Received: 10/03/2006] [Accepted: 03/14/2007] [Indexed: 10/23/2022] Open
Abstract
AIMS The study objective was to investigate the effects of axillary lymph node clearance surgery on the function and morphology of the lymphatic system of the upper limb in women with breast cancer. METHODS Nineteen women were studied before and 3 months after surgery. Fifteen were studied again 12 months after surgery. On each occasion, scintigraphy following intradermal hand webspace injection of Tc-99m-human polyclonal immunoglobulin was performed to include the affected upper limb and torso. RESULTS There was considerable functional variability in response to surgery. Seven patients subsequently developed breast cancer-related lymphedema (BCRL). Neither lymph re-routing (defined as a change in lymph vessel morphology or definition) nor linear velocity of protein transit up the arm was associated with the development of BCRL. Blood pool activity, judged from visual inspection of the cardiac blood pool on the whole body images, was earlier and more marked 3 and 12 months after surgery than before. The count rate (per 100 pixels/MBq injected activity), measured in a cardiac region of interest, was significantly higher after surgery than before, was higher in patients who developed BCRL and, in the patient population as a whole, correlated positively with arm swelling. CONCLUSION The consequences of axillary lymph node clearance were variable, unexpected and largely persistent. An increased rate of access of intradermally injected protein into the blood pool is significantly associated with BCRL.
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Affiliation(s)
- S O'Mahony
- Cambridge Breast Unit, Addenbrooke's Hospital, Cambridge University Hospitals NHS Trust, Cambridge, UK
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38
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Fowler JC, Beadsmoore C, Gaskarth MTG, Cheow HK, Bernal R, Hegarty P, Bullock KN, Taylor H, Dixon AK, Peters AM. A simple processing method allowing comparison of renal enhancing volumes derived from standard portal venous phase contrast-enhanced multidetector CT images to derive a CT estimate of differential renal function with equivalent results to nuclear medicine quantification. Br J Radiol 2006; 79:935-42. [PMID: 16971420 DOI: 10.1259/bjr/53140218] [Citation(s) in RCA: 14] [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: 11/05/2022] Open
Abstract
As iodinated contrast medium is cleared by glomerular filtration, it should be possible to apply the same principles utilized in radionuclide studies to derive differential renal function by comparison of enhancing renal volumes derived from contrast enhanced multidetector CT (CEMDCT). Having established a technique iteratively which appeared successful, a retrospective study was performed using 25 consecutive patients with a wide range of urological conditions who had undergone both CEMDCT, including the renal area in the portal venous phase, and nuclear medicine (NM) assessment of renal function with no urological intervention between the studies. Proprietary volume software was used to quantify the volume and attenuation of each kidney, the products of which (after subtraction of soft tissue attenuation derived from a region of interest over psoas) gave right and left enhancing renal volumes. The contribution by each kidney as a percentage of total renal enhancing tissue was derived. Comparison with NM studies resulted in excellent correlation of relative renal function by CEMDCT and NM assessments having a regression of near unity and a Pearson's correlation coefficient of 0.96. Bland Altman and Passing Bablock tests confirmed good agreement between the two methods with no bias. This is a simple, practicable processing technique using standard portal venous phase CEMDCT images to quantify differential function. This technique may allow a one-stop CT assessment of both anatomy and function.
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Affiliation(s)
- J C Fowler
- Department of Radiology, Addenbrooke's Hospital and the University of Cambridge, Cambridge, UK
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39
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Peters AM, Blair CK, Verneris MR, Neglia JP, Robison LL, Spector LG, Reaman GH, Felix CA, Ross JA. Maternal hemoglobin concentration during pregnancy and risk of infant leukaemia: a children's oncology group study. Br J Cancer 2006; 95:1274-6. [PMID: 17003777 PMCID: PMC2360554 DOI: 10.1038/sj.bjc.6603388] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
In contrast to the positive association found in three studies between maternal anaemia during pregnancy and childhood leukaemia, no such association was found in infant leukaemia (odds ratio 0.85, 95% confidence interval 0.53–1.37).
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Affiliation(s)
- A M Peters
- Department of Pediatrics, University of Minnesota, 420 Delaware St. SE, Minneapolis, MN 55455, USA
| | - C K Blair
- Department of Pediatrics, University of Minnesota, 420 Delaware St. SE, Minneapolis, MN 55455, USA
| | - M R Verneris
- Department of Pediatrics, University of Minnesota, 420 Delaware St. SE, Minneapolis, MN 55455, USA
| | - J P Neglia
- Department of Pediatrics, University of Minnesota, 420 Delaware St. SE, Minneapolis, MN 55455, USA
- Children's Oncology Group, 440 E. Huntington Drive, Suite 300, Arcadia, CA 91006, USA
| | - L L Robison
- Children's Oncology Group, 440 E. Huntington Drive, Suite 300, Arcadia, CA 91006, USA
- St. Jude's Research Hospital, 332 North Lauderdale St., Memphis, TN 38105, USA
| | - L G Spector
- Department of Pediatrics, University of Minnesota, 420 Delaware St. SE, Minneapolis, MN 55455, USA
- Children's Oncology Group, 440 E. Huntington Drive, Suite 300, Arcadia, CA 91006, USA
| | - G H Reaman
- Children's Oncology Group, 440 E. Huntington Drive, Suite 300, Arcadia, CA 91006, USA
- Children's Oncology Group—Chair's Office, 4600 East West Highway, Bethesda, MD 20814, USA
| | - C A Felix
- Children's Oncology Group, 440 E. Huntington Drive, Suite 300, Arcadia, CA 91006, USA
- Children's Hospital of Philadelphia, 3516 Civic Center Boulevard, Philadelphia, PA 19104, USA
| | - J A Ross
- Department of Pediatrics, University of Minnesota, 420 Delaware St. SE, Minneapolis, MN 55455, USA
- Children's Oncology Group, 440 E. Huntington Drive, Suite 300, Arcadia, CA 91006, USA
- Division of Pediatric Epidemiology & Clinical Research, University of Minnesota Department of Pediatrics, 420 Delaware St. SE, MMC 422, Minneapolis, MN 55455, USA. E-mail:
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Abstract
The advantages of event-related functional Magnetic Resonance Imaging (fMRI) and the increasing use of fMRI in cognitive experiments are both driving the development of techniques that allow images sensitive to the blood oxygen level-dependent effect to be acquired at ever-higher temporal resolution. Here, we present a technique based on the use of echo shifting (ES) in conjunction with a multislice (MS) echo planar imaging (EPI) readout, which allows T2*-weighted images to be generated with a repetition time per slice that is less than the echo time (TE). Using this ES-MS-EPI approach, it is shown that images with a TE of 40 ms can be acquired with an acquisition time per slice of only 27 ms. The utility of the MS-ES-EPI sequence is demonstrated in a visual-motor, event-related fMRI study in which nine-slice image volumes are acquired continuously at a rate of 4.1 Hz. The sequence is shown to produce reliable activation associated with both visual stimuli and motor actions.
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Affiliation(s)
- Andrew Gibson
- Sir Peter Mansfield Magnetic Resonance Centre, School of Physics and Astronomy, University of Nottingham, NG7 2RD Nottingham, UK
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Peters AM. A brief history of cell labelling. Q J Nucl Med Mol Imaging 2005; 49:304-7. [PMID: 16407813] [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] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
The term cell labelling is usually used in the context of labelled leukocytes for imaging inflammation and labelled platelets for imaging thrombosis. Erythrocyte labelling for in vitro measurements of red cell life span, in vivo measurements of splenic red cell pooling, radionuclide ventriculography and imaging sites of bleeding has developed rather separately and has a different history. Labelled platelets and leukocytes were originally developed for cell kinetic studies. Since the current-day applications of labelled platelets and leukocytes depend on a clear understanding of cell kinetics, these classical studies are important and relevant to the history of cell labelling.
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Affiliation(s)
- A M Peters
- School of Applied Physiology, Brighton and Sussex Medical School, Royal Sussex County Hospital, Eastern Road, Brighton BN2 4BE, UK.
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Beadsmoore CJ, Cheow HK, Dutton JAE, Peters AM. Polycystic kidneys and renal transplant imaging. Clin Nucl Med 2005; 30:537-9. [PMID: 16024947 DOI: 10.1097/01.rlu.0000170011.45545.5f] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Renal transplantation is an ever-increasing procedure. Baseline DTPA renography is routinely performed in these patients in many centers to assess transplant perfusion and function. This report describes 2 cases of unusual appearance at renography resulting from the native polycystic kidneys.
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Affiliation(s)
- C J Beadsmoore
- Department of Nuclear Medicine, Addenbrooke's Hospital, Cambridge, UK
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Stanton AWB, Mellor RH, Cook GJ, Svensson WE, Peters AM, Levick JR, Mortimer PS. Impairment of lymph drainage in subfascial compartment of forearm in breast cancer-related lymphedema. Lymphat Res Biol 2005; 1:121-32. [PMID: 15624420 PMCID: PMC1351042 DOI: 10.1089/153968503321642615] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.7] [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: 11/13/2022] Open
Abstract
BACKGROUND In arm lymphedema secondary to axillary surgery and radiotherapy (breast cancer-related lymphedema), the swelling is largely epifascial and lymph flow per unit epifascial volume is impaired. The subfascial muscle compartment is not measurably swollen despite the iatrogenic damage to its axillary drainage pathway, but this could be due to its low compliance. Our aim was to test the hypothesis that subfascial lymph drainage too is impaired. METHODS AND RESULTS Quantitative lymphoscintigraphy was used to measure the removal rate constant (local lymph flow per unit distribution volume) for technetium-99m-human immunoglobulin G injected intramuscularly in the forearms of nine women with unilateral lymphedema. The removal rate constant was on average 31% lower in the ipsilateral swollen forearm than in the contralateral forearm (swollen arm: -0.096+/-0.041% min(-1), contralateral arm: -0.138+/-0.037% min(-1); mean+/-SD, p = 0.037). The decrease in subfascial rate constant correlated strongly with increase in arm volume (r = -0.88, p = 0.002), even though the swelling is mainly epifascial. There was no convincing evidence of dermal backflow. CONCLUSIONS Lymph flow in the subfascial muscle compartment is decreased in breast cancer-related lymphedema. The correlation between impairment of subfascial drainage and epifascial arm swelling could be because both depend on the severity of axillary damage, or because loss of function in subfascial lymphatics impairs drainage from the epifascial to the subfascial system.
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Affiliation(s)
- A W B Stanton
- Department of Medicine, St George's Hospital Medical School, London.
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Patel A, Pain SJ, Britton P, Sinnatamby R, Warren R, Bobrow L, Barber RW, Peters AM, Purushotham AD. Radioguided occult lesion localisation (ROLL) and sentinel node biopsy for impalpable invasive breast cancer. Eur J Surg Oncol 2004; 30:918-23. [PMID: 15498634 DOI: 10.1016/j.ejso.2004.07.008] [Citation(s) in RCA: 11] [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] [Accepted: 07/05/2004] [Indexed: 10/26/2022] Open
Abstract
AIM The aim of this study was to simplify the technique of ROLL and sentinel node biopsy without compromising tumour excision and sentinel node biopsy. METHODS Twenty patients with impalpable primary invasive breast carcinoma underwent an injection of 99mTc-nanocolloid mixed with radiographic contrast medium Iohexol into the centre of the lesion under ultrasound or stereotactic guidance pre-operatively. No guidewire localisation was performed. Under general anaesthesia, a periareolar intradermal/subcutaneous injection of patent blue-V dye was performed. The sentinel node was identified by blue-stained lymphatics and node and a hot spot on the gamma probe. Surgical excision of the primary tumour was then carried out using the gamma probe. RESULTS In eight of 20 cases an immediate re-excision was carried out and on histological assessment, all 20 patients were clear of invasive disease at the margins. In two patients, in situ disease was present at the margins and a further re-excision was therefore performed. The sentinel node was identified in all cases. In all, five of 20 patients were node positive on routine HE staining. In a further two patients, tumour cells were identified by immunohistochemistry with CAM5.2 antibody. Completion axillary clearance in six patients confirmed that the sentinel node was the only positive node. CONCLUSIONS This modification of the previously described ROLL technique is feasible and safe and does not compromise tumour excision or sentinel node detection.
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Affiliation(s)
- A Patel
- Cambridge Breast Unit, Addenbrooke's Hospital, Cambridge, UK
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Pain SJ, Purushotham AD, Barber RW, Ballinger JR, Solanki CK, Mortimer PS, Peters AM. Variation in lymphatic function may predispose to development of breast cancer-related lymphoedema. Eur J Surg Oncol 2004; 30:508-14. [PMID: 15135478 DOI: 10.1016/j.ejso.2004.02.008] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/18/2004] [Indexed: 10/26/2022] Open
Abstract
AIMS Breast cancer-related lymphoedema (BCRL) remains a common complication of breast cancer treatment. Many features of this condition remain poorly understood, such as why only approximately 25% of women are affected after similar treatment, and the phenomenon of 'sparing', in which regions of an otherwise swollen arm, most commonly the hand, remain unaffected. This study uses dual-isotope lymphoscintigraphy, involving measurement of rate of clearance of radiolabelled protein from a subcutaneous depot and subsequent appearance in blood, to quantify alterations in lymphatic function in women with BCRL, and to further investigate differences between those in whom the hand is involved with swelling and those in whom it is spared. METHODS Participants received a depot injection of human immunoglobulin G in the dorsum of both hands, labeled with technetium-99m on one side and indium-111 on the other. Rates of clearance from the depot and appearance in venous blood were measured at regular intervals over a 3 h period. RESULTS A total of 18 women with a history of BCRL were studied. Significant reductions in both depot clearance and venous appearance were observed in the affected arm compared with the unaffected contralateral control. On sub-group analysis, significant differences were also observed between swollen and spared hand groups, both for the affected and unaffected contralateral arm. DISCUSSION This study, as well as confirming impaired lymphatic function in arms affected by BCRL, also shows underlying variation in lymphatic function in the unaffected contralateral arm, between those with and without hand sparing. This raises the possibility that the risk of developing BCRL may be, in part, pre-determined.
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Affiliation(s)
- S J Pain
- Cambridge Breast Unit, Box 97, Addenbrooke's Hospital, Hills Road, Cambridge CB2 2QQ, UK
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Price CJS, Menon DK, Peters AM, Ballinger JR, Barber RW, Balan KK, Lynch A, Xuereb JH, Fryer T, Guadagno JV, Warburton EA. Cerebral neutrophil recruitment, histology, and outcome in acute ischemic stroke: an imaging-based study. Stroke 2004; 35:1659-64. [PMID: 15155970 DOI: 10.1161/01.str.0000130592.71028.92] [Citation(s) in RCA: 127] [Impact Index Per Article: 6.4] [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: 11/16/2022]
Abstract
BACKGROUND AND PURPOSE Evidence now exists for a pathogenic role for neutrophils in acute cerebral ischemia. We have studied the patterns and temporal profile of cerebral neutrophil recruitment to areas of acute ischemic stroke (IS) and have attempted to correlate this with neurological status and outcome. METHODS Patients with cortical middle cerebral artery (MCA) IS were recruited within 24 hours of clinical onset. Neutrophil recruitment was studied using indium-111 (111In) troponolate-labeled neutrophils, planar imaging, and single-photon emission computed tomography (SPECT). Volume of brain infarction was calculated from concurrent computed tomography (CT). Hematoxylin and eosin sections were obtained postmortem (n=2). Outcome was measured using Barthel, Rankin, and National Institute of Health Stroke (NIHSS) scales. RESULTS Fifteen patients were studied. Significant 111In-neutrophil recruitment to ipsilateral hemisphere, as measured by asymmetry index (AI), was demonstrated within 24 hours of onset in 9 patients; this response was heterogenous between patients and on repeated measurement attenuated over time. Histologically, recruitment was confirmed within intravascular, intramural, and intraparenchymal compartments. Interindividual heterogeneity in neutrophil response did not correlate with infarct volume or outcome. In an exploratory analysis, neutrophil accumulation appeared to correlate significantly with infarct expansion (Spearman rho=0.66; P=0.03, n=12). CONCLUSIONS Neutrophils recruit to areas of ischemic brain within 24 hours of symptom onset. This recruitment attenuates over time and is confirmed histologically. While neutrophil accumulation may be associated with either the magnitude or the rate of infarct growth, these results require confirmation in future studies.
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Affiliation(s)
- C J S Price
- University of Cambridge Department of Medicine, Hospital, Cambridge, UK.
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Pain SJ, Barber RW, Ballinger JR, Solanki CK, Mortimer PS, Purushotham AD, Peters AM. Tissue-to-Blood Transport of Radiolabelled Immunoglobulin Injected into the Web Spaces of the Hands of Normal Subjects and Patients with Breast Cancer-Related Lymphoedema. J Vasc Res 2004; 41:183-92. [PMID: 15017112 DOI: 10.1159/000077289] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2003] [Accepted: 01/18/2004] [Indexed: 11/19/2022] Open
Abstract
AIM The ability to return interstitial protein to central blood is key to the defence against oedema. The aim of this study was to quantify this ability by measuring the rate at which radiolabelled human immunoglobulin (HIgG) accumulated in blood following injection into the subcutis of the hand in normal volunteers and in patients with breast cancer-related lymphoedema (BCRL). METHODS A total of 37 control subjects (healthy normal volunteers or breast cancer patients prior to treatment) and 18 women with BCRL were studied with dual-isotope lymphoscintigraphy. Each received bilateral subcutaneous depot injection in the dorsal web space of HIgG labelled with Tc-99m on one side and In-111 on the other. Activities remaining at the depot and accumulating in blood were measured at regular intervals for 3 h. Clearance from the depot was exponential and expressed as the rate constant k(depot) (min(-1)). Accumulation in blood was essentially linear and, using an estimate of blood volume based on height and weight, was expressed as the linear constant b(blood) (% administered activity x min(-1)). The time axis intercept of this linear fit was recorded as an index of the minimum time to arrival of radioprotein in blood. The efficiency with which radioprotein that has left the depot (extra-depot activity) is transported into blood [tissue-to-blood (T-B) transport] was quantified (1) as the quotient b(blood)/k(depot), and (2) as a function of time after injection by comparing the total amount of radioprotein in blood at any time with the total amount of radioprotein that was no longer in the depot at the same time. RESULTS Tc-99m-HIgG and In-111-HIgG behaved similarly and are interchangeable. At all times between 60 and 180 min in controls, about 50% of protein that had left the depot was present in blood. T-B transport was reduced to about 20% in BCRL arms in which the hand was involved in swelling (p < 0.001 versus controls), but remained unchanged in patients in whom the hand was spared. The minimum time to arrival of radioprotein in blood was not reduced in BCRL; on the contrary, there appeared to be a small proportion of injected activity that arrived rapidly in blood in BCRL patients but not in controls. CONCLUSION We conclude that T-B transport is only impaired in BCRL when radioprotein is injected into swollen tissue. Significant quantities of radioprotein may escape from the arm via local access to blood. Individual variation in this capacity may explain the regional sparing observed in BCRL.
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Affiliation(s)
- S J Pain
- Cambridge Breast Unit, Addenbrooke's Hospital, Cambridge, UK
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Hardy G, Worrell S, Hayes P, Barnett CM, Glass D, Pido-Lopez J, Imami N, Aspinall R, Dutton J, Gazzard B, Peters AM, Gotch FM. Evidence of thymic reconstitution after highly active antiretroviral therapy in HIV-1 infection. HIV Med 2004; 5:67-73. [PMID: 15012644 DOI: 10.1111/j.1468-1293.2004.00187.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [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: 11/28/2022]
Abstract
OBJECTIVES We aimed to provide evidence of thymic reconstitution after highly active antiretroviral therapy (HAART) in HIV-1 infected patients and to correlate this with the restoration of peripheral naïve T cells. METHODS Positron emission tomography (PET) enables definitive evidence of thymic activity, indicating functional potential. In this case study, a single patient who initiated HAART demonstrated reconstitution of the naïve T-cell pool and underwent thymic PET scans at baseline and 2 and 6 months following initiation of therapy. Two patients who failed to demonstrate such reconstitution acted as controls. These patients (mean age 27 years) had chronic HIV infection with low CD4 T-cell counts (mean 82, range 9-160 cells/microL blood). Increased function of the thymus visualized by PET was correlated with phenotypic changes in CD4 and CD8 T cells in the periphery measured by flow cytometry, and with numbers of recent thymic emigrants measured by quantification of the numbers of T-cell receptor excision circles (TRECs) in peripheral cells. RESULTS In one patient, clear correlations could be drawn between visible activity within the thymus, as measured by increased [F18]fluorodeoxyglucose (FDG) uptake, and regeneration of naïve CD4 (CD45RA/CD62L) T cells, increased numbers of CD4 T cells, controlled viraemia and increased numbers of recent thymic emigrants. A second patient displayed no increase in peripheral CD4 count and no increase in thymic activity. The third patient elected to stop therapy following the 2-month time point. CONCLUSIONS The use of PET suggests that thymic activity may increase after HAART, indicating that the thymus has the potential to be functional even in HIV-1 infected persons with low CD4 T-cell counts.
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Affiliation(s)
- G Hardy
- Department of Immunology, Imperial College London, Chelsea and Westminster Hospital, London, UK.
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