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Beckers C, Vasilikos L, Sanchez Fernandez A, Moor L, Pruschy M. Targeting the survival kinase DYRK1B: A novel approach to overcome radiotherapy-related treatment resistance. Radiother Oncol 2024; 190:110039. [PMID: 38040123 DOI: 10.1016/j.radonc.2023.110039] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Revised: 11/07/2023] [Accepted: 11/23/2023] [Indexed: 12/03/2023]
Abstract
BACKGROUND Cancer cell survival under stress conditions is a prerequisite for the development of treatment resistance. The survival kinase DYRK1B is a key regulator of stress survival pathways and might thereby also contribute to radiation resistance. Here we investigate the strategy of targeting DYRK1B in combination with ionizing radiation (IR) to enhance tumor cell killing under stress conditions. METHODS DYRK1B expression, ROS formation and DNA damage were investigated under serum-starvation (0.1% FBS), hypoxia (0.2%, 1% O2) and IR. The combined treatment modality of IR and DYRK1B inhibition was investigated in 2D and in spheroids derived from the colorectal cancer cell line SW620, and in primary patient-derived colorectal carcinoma (CRC) organoids. RESULTS Expression of DYRK1B was upregulated under starvation and hypoxia, but not in response to IR. The small molecule DYRK1B inhibitor AZ191 and shRNA-mediated DYRK1B knockdown significantly reduced proliferative activity and clonogenicity of SW620 tumor cells alone and in combination with IR under serum-starved conditions, which correlated with increased ROS levels and DNA damage. Furthermore, AZ191 successfully targeted the hypoxic core of tumor spheroids while IR preferentially targeted normoxic cells in the rim of the spheroids. A combined treatment effect was also observed in CRC-organoids but not in healthy tissue-derived organoids. CONCLUSION Combined treatment with the DYRK1B inhibitor AZ191 and IR resulted in (supra-) additive tumor cell killing in colorectal tumor cell systems and in primary CRC organoids. Mechanistic investigations support the rational to target the stress-enhanced survival kinase DYRK1B in combination with irradiation to overcome hypoxia- and starvation-induced treatment resistances.
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Affiliation(s)
- Claire Beckers
- Laboratory for Applied Radiobiology, Department of Radiation Oncology, University Hospital Zurich, University of Zurich, Zurich, Switzerland.
| | - Lazaros Vasilikos
- Laboratory for Applied Radiobiology, Department of Radiation Oncology, University Hospital Zurich, University of Zurich, Zurich, Switzerland.
| | - Alba Sanchez Fernandez
- Laboratory for Applied Radiobiology, Department of Radiation Oncology, University Hospital Zurich, University of Zurich, Zurich, Switzerland.
| | - Lorena Moor
- Laboratory for Applied Radiobiology, Department of Radiation Oncology, University Hospital Zurich, University of Zurich, Zurich, Switzerland.
| | - Martin Pruschy
- Laboratory for Applied Radiobiology, Department of Radiation Oncology, University Hospital Zurich, University of Zurich, Zurich, Switzerland.
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Beckers C, Pruschy M, Vetrugno I. Tumor hypoxia and radiotherapy: A major driver of resistance even for novel radiotherapy modalities. Semin Cancer Biol 2024; 98:19-30. [PMID: 38040401 DOI: 10.1016/j.semcancer.2023.11.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2023] [Revised: 11/16/2023] [Accepted: 11/22/2023] [Indexed: 12/03/2023]
Abstract
Hypoxia in solid tumors is an important predictor of poor clinical outcome to radiotherapy. Both physicochemical and biological processes contribute to a reduced sensitivity of hypoxic tumor cells to ionizing radiation and hypoxia-related treatment resistances. A conventional low-dose fractionated radiotherapy regimen exploits iterative reoxygenation in between the individual fractions, nevertheless tumor hypoxia still remains a major hurdle for successful treatment outcome. The technological advances achieved in image guidance and highly conformal dose delivery make it nowadays possible to prescribe larger doses to the tumor as part of single high-dose or hypofractionated radiotherapy, while keeping an acceptable level of normal tissue complication in the co-irradiated organs at risk. However, we insufficiently understand the impact of tumor hypoxia to single high-doses of RT and hypofractionated RT. So-called FLASH radiotherapy, which delivers ionizing radiation at ultrahigh dose rates (> 40 Gy/sec), has recently emerged as an important breakthrough in the radiotherapy field to reduce normal tissue toxicity compared to irradiation at conventional dose rates (few Gy/min). Not surprisingly, oxygen consumption and tumor hypoxia also seem to play an intriguing role for FLASH radiotherapy. Here we will discuss the role of tumor hypoxia for radiotherapy in general and in the context of novel radiotherapy treatment approaches.
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Affiliation(s)
- Claire Beckers
- Laboratory for Applied Radiobiology, Department of Radiation Oncology, University Hospital Zurich, University of Zurich, Zurich, Switzerland
| | - Martin Pruschy
- Laboratory for Applied Radiobiology, Department of Radiation Oncology, University Hospital Zurich, University of Zurich, Zurich, Switzerland.
| | - Irene Vetrugno
- Laboratory for Applied Radiobiology, Department of Radiation Oncology, University Hospital Zurich, University of Zurich, Zurich, Switzerland
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Cuypers ML, Chanteux H, Gillent E, Bonnaillie P, Saunders K, Beckers C, Delatour C, Dell'Aiera S, Ungell AL, Nicolaï J. (-)- N-3-Benzylphenobarbital Is Superior to Omeprazole and (+)- N-3-Benzylnirvanol as a CYP2C19 Inhibitor in Suspended Human Hepatocytes. Drug Metab Dispos 2020; 48:1121-1128. [PMID: 32839278 DOI: 10.1124/dmd.120.000089] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2020] [Accepted: 07/31/2020] [Indexed: 11/22/2022] Open
Abstract
Early assessment of metabolism pathways of new chemical entities guides the understanding of drug-drug interactions. Selective enzyme inhibitors are indispensable in CYP reaction phenotyping. The most commonly applied CYP2C19 inhibitor, omeprazole, lacks selectivity. Two promising alternatives, (+)-N-3-benzylnirvanol and (-)-N-3-benzylphenobarbital, are already used as CYP2C19 inhibitors in some in vitro studies with suspended human hepatocytes. However, a full validation proving their suitability in terms of CYP and non-CYP selectivity has not been presented in literature. The present study provides a thorough comparison between omeprazole, (+)-N-3-benzylnirvanol, and (-)-N-3-benzylphenobarbital in terms of potency and selectivity and shows the superiority of (-)-N-3-benzylphenobarbital as a CYP2C19 inhibitor in suspended human hepatocytes. Furthermore, we evaluated the application of (-)-N-3-benzylphenobarbital to predict the in vivo contribution of CYP2C19 to drug metabolism [fraction metabolized (fm) of CYP2C19, fmCYP2C19]. A set of 10 clinically used CYP2C19 substrates with reported in vivo fmCYP2C19 data was evaluated. fmCYP2C19, which was predicted using data from suspended human hepatocyte incubations, underestimated the in vivo fmCYP2C19 The use of a different hepatocyte batch with a different CYP3A4/CYP2C19 activity ratio showed the impact of intrinsic CYP activities on the determination of fmCYP2C19 Overall, this study confirms the selective CYP2C19 inhibition by (-)-N-3-benzylphenobarbital over other CYP isoforms (CYP1A2, CYP2B6, CYP2C8, CYP2C9, CYP2D6, and CYP3A4) and clinically relevant non-CYP enzymes [aldehyde oxidase, flavin-containing monooxygenase 3, N-acetyltransferase 2, uridine diphosphate glucuronosyltransferase (UGT) 1A1, UGT1A4, UGT2B7, UGT2B15] in suspended human hepatocytes. (-)-N-3-benzylphenobarbital is therefore the preferred CYP2C19 inhibitor to assess fmCYP2C19 in suspended human hepatocytes in comparison with omeprazole and (+)-N-3-benzylnirvanol. SIGNIFICANCE STATEMENT: (-)-N-3-Benzylphenobarbital is a more potent and selective inhibitor of CYP2C19 in suspended human hepatocytes than omeprazole and (+)-N-3-benzylnirvanol. (-)-N-3-Benzylphenobarbital can be used to predict the fraction metabolized by CYP2C19 in suspended human hepatocytes.
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Affiliation(s)
- Marie-Lynn Cuypers
- Pharmaceutical Sciences, KU Leuven, Leuven, Belgium (M.-L.C., C.B.) and Development Science, UCB Biopharma SRL, Braine-l'Alleud, Belgium (H.C., E.G., P.B., K.S., C.D., S.D., A.-L.U., J.N.)
| | - Hugues Chanteux
- Pharmaceutical Sciences, KU Leuven, Leuven, Belgium (M.-L.C., C.B.) and Development Science, UCB Biopharma SRL, Braine-l'Alleud, Belgium (H.C., E.G., P.B., K.S., C.D., S.D., A.-L.U., J.N.)
| | - Eric Gillent
- Pharmaceutical Sciences, KU Leuven, Leuven, Belgium (M.-L.C., C.B.) and Development Science, UCB Biopharma SRL, Braine-l'Alleud, Belgium (H.C., E.G., P.B., K.S., C.D., S.D., A.-L.U., J.N.)
| | - Pierre Bonnaillie
- Pharmaceutical Sciences, KU Leuven, Leuven, Belgium (M.-L.C., C.B.) and Development Science, UCB Biopharma SRL, Braine-l'Alleud, Belgium (H.C., E.G., P.B., K.S., C.D., S.D., A.-L.U., J.N.)
| | - Kenneth Saunders
- Pharmaceutical Sciences, KU Leuven, Leuven, Belgium (M.-L.C., C.B.) and Development Science, UCB Biopharma SRL, Braine-l'Alleud, Belgium (H.C., E.G., P.B., K.S., C.D., S.D., A.-L.U., J.N.)
| | - Claire Beckers
- Pharmaceutical Sciences, KU Leuven, Leuven, Belgium (M.-L.C., C.B.) and Development Science, UCB Biopharma SRL, Braine-l'Alleud, Belgium (H.C., E.G., P.B., K.S., C.D., S.D., A.-L.U., J.N.)
| | - Claude Delatour
- Pharmaceutical Sciences, KU Leuven, Leuven, Belgium (M.-L.C., C.B.) and Development Science, UCB Biopharma SRL, Braine-l'Alleud, Belgium (H.C., E.G., P.B., K.S., C.D., S.D., A.-L.U., J.N.)
| | - Sylvie Dell'Aiera
- Pharmaceutical Sciences, KU Leuven, Leuven, Belgium (M.-L.C., C.B.) and Development Science, UCB Biopharma SRL, Braine-l'Alleud, Belgium (H.C., E.G., P.B., K.S., C.D., S.D., A.-L.U., J.N.)
| | - Anna-Lena Ungell
- Pharmaceutical Sciences, KU Leuven, Leuven, Belgium (M.-L.C., C.B.) and Development Science, UCB Biopharma SRL, Braine-l'Alleud, Belgium (H.C., E.G., P.B., K.S., C.D., S.D., A.-L.U., J.N.)
| | - Johan Nicolaï
- Pharmaceutical Sciences, KU Leuven, Leuven, Belgium (M.-L.C., C.B.) and Development Science, UCB Biopharma SRL, Braine-l'Alleud, Belgium (H.C., E.G., P.B., K.S., C.D., S.D., A.-L.U., J.N.)
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Borosch S, Kraemer S, Dahmen E, Hoß M, Denecke B, Beckers C, Stoppe C, Goetzenich A, Autschbach R. Extracellular Vesicles: New Mediators in Cardiac Preconditioning? Thorac Cardiovasc Surg 2017. [DOI: 10.1055/s-0037-1598937] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Affiliation(s)
- S. Borosch
- University Hospital Aachen, Department of Thoracic and Cardiovascular Surgery, Aachen, Germany
| | - S. Kraemer
- University Hospital Aachen, Department of Thoracic and Cardiovascular Surgery, Aachen, Germany
| | - E. Dahmen
- University Hospital Aachen, Department of Thoracic and Cardiovascular Surgery, Aachen, Germany
| | - M. Hoß
- University Hospital Aachen, Electron Microscopic Facility, Institute of Pathology, Aachen, Germany
| | - B. Denecke
- University Hospital Aachen, Interdisciplinary Center for Clinical Research, Aachen, Germany
| | - C. Beckers
- University Hospital Aachen, Department of Thoracic and Cardiovascular Surgery, Aachen, Germany
| | - C. Stoppe
- University Hospital Aachen, Department of Intensive Care Medicine, Aachen, Germany
| | - A. Goetzenich
- University Hospital Aachen, Department of Thoracic and Cardiovascular Surgery, Aachen, Germany
| | - R. Autschbach
- University Hospital Aachen, Department of Thoracic and Cardiovascular Surgery, Aachen, Germany
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5
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Borosch S, Kraemer S, Nosirov B, Habibullo S, Beckers C, Stoppe C, Goetzenich A, Autschbach R. Cardioprotective Effects of Dantrolene and Thymoquinone in H9c2 Cells: Does the Phenotype Matter? Thorac Cardiovasc Surg 2017. [DOI: 10.1055/s-0037-1598944] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Affiliation(s)
- S. Borosch
- University Hospital Aachen, Department of Thoracic and Cardiovascular Surgery, Aachen, Germany
| | - S. Kraemer
- University Hospital Aachen, Department of Thoracic and Cardiovascular Surgery, Aachen, Germany
| | - B. Nosirov
- University Hospital Aachen, Department of Thoracic and Cardiovascular Surgery, Aachen, Germany
| | - S. Habibullo
- University Hospital Aachen, Department of Thoracic and Cardiovascular Surgery, Aachen, Germany
| | - C. Beckers
- University Hospital Aachen, Department of Thoracic and Cardiovascular Surgery, Aachen, Germany
| | - C. Stoppe
- University Hospital Aachen, Department of Intensive Care Medicine, Aachen, Germany
| | - A. Goetzenich
- University Hospital Aachen, Department of Thoracic and Cardiovascular Surgery, Aachen, Germany
| | - R. Autschbach
- University Hospital Aachen, Department of Thoracic and Cardiovascular Surgery, Aachen, Germany
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6
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De Nayer P, Sauvage P, De Coster P, Hermans J, Beckers C. Abstracts of the meeting of the Belgian Society of Endocrinology (20 October & 17 November 1984). Acta Clin Belg 2016. [DOI: 10.1080/22953337.1985.11719055] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Affiliation(s)
- Th. Weber
- Services de Pneumologie, CHU Sart Tilman, 4000 Lifcge
| | - C. Beckers
- Services de Pneumologie, CHU Sart Tilman, 4000 Lifcge
| | - O. Kaye
- Nephrologie, CHU Sart Tilman, 4000 Lifcge
| | - Y. Comhaire
- Rhumatologieet, CHU Sart Tilman, 4000 Lifcge
| | - M. Malaise
- Onhtalmologie, CHU Sart Tilman, 4000 Lifcge
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8
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Kraemer S, Beckers C, Stoppe C, Goetzenich A, Autschbach R. Exosomes in Cardiac Preconditioning with Isoflurane and Hypoxia. Thorac Cardiovasc Surg 2015. [DOI: 10.1055/s-0035-1544519] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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9
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Delanaye P, Beckers C, Hustinx R. Le néphrogramme isotopique (méthode de « Gates ») permet-il une estimation correcte du débit de filtration glomérulaire ? Revue de la littérature. Nephrol Ther 2014. [DOI: 10.1016/j.nephro.2014.07.142] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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10
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Cousin F, Alvarez V, Beckers C, Hustinx R, Simoni P. [Image of the month: Neurogenic myositis ossificans]. Rev Med Liege 2013; 68:53-55. [PMID: 23469483] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Affiliation(s)
- F Cousin
- Service d'Imagerie Médicale, CHU de Liège
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Vander Borght T, Pauwels S, Lambotte L, De Saeger C, Beckers C. Synthesis of [2-14C]thymidine: A potential route for [2-11C]thymidine. J Labelled Comp Radiopharm 2006. [DOI: 10.1002/jlcr.2580280711] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Affiliation(s)
- B F C Kafsack
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, 615 North Wolfe Street, Baltimore, MD 21205-1918, USA.
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Beckers C, Foidart J, Thiry A, Malaise MG. [Synovial metastases from colonic cancer presenting as arthritis of the knee. Characterization by 18FDG PET scan]. Rev Med Liege 2002; 57:467-74. [PMID: 12233224] [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: 02/26/2023]
Abstract
A case of carcinomatous monoarthritis involving the left knee due to colonic adenocarcinoma is described. Large recurrent synovial effusion, that will be later hematic, lytic lesion of the bones and chondrolysis were noted. Knee positron emitting tomography scan using FDG (FDG-PET) revealed a diffuse increased uptake in soft tissues assumed to be synovium, the hypertrophy of which was identified by ultrasonography. Whole body PET scan showed extensive lymph node, visceral and bone metastases, suggesting that the increase in the synovium could also be of metastatic origin. The final diagnosis of synovial carcinomatosis secondary to the known colonic adenocarcinoma was confirmed by histological analysis of biopsies obtained by arthroscopy. A review of the literature is realised. To our knowledge, this is the first synovial metastasis studied by FDG-PET.
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Affiliation(s)
- C Beckers
- Département de Médecine Interne, Service de Médecine Nucléaire, CHU Sart Tilman
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14
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Belhocine T, Kaye O, Delanaye P, Corman V, Baghaie M, Deprez M, Daenen F, De Barsy C, Beckers C, Gomez P, Hustinx R, Foidart-Willems J, Demonty J, Malaise M, Rigo P. [Horton's disease and extra-temporal vessel locations: role of 18FDG PET scan. Report of 3 cases and review of the literature]. Rev Med Interne 2002; 23:584-91. [PMID: 12162214 DOI: 10.1016/s0248-8663(02)00620-3] [Citation(s) in RCA: 20] [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] [Indexed: 11/19/2022]
Abstract
PURPOSE We report three cases of Horton's disease, in which F18-Fluorine-2-Deoxy-D-Glucose (18FDG) positron emission tomography (PET) demonstrated a clinically unsuspected extra-cranial vessels hypermetabolism. METHODS Fully corrected whole-body PET was performed in three patients (two women, one man) for exploring a marked inflammatory syndrome. Scanning was acquired 60 min after i.v. injection of 222 MBq of 18FDG in average. RESULTS In two patients with histologically proven Horton's disease, PET alone showed increased glucose metabolism involving the carotid and sub-clavian arteries as well as the ascending aorta, aortic arch, thoracic and abdominal aorta, and the iliac and femoral arteries. In the third patient, by detecting cervical, thoracic and abdominal vessel hypermetabolism, PET non-invasively contributed to the diagnosis of giant cell arteritis. All patients had complete clinical and biological response to corticoids. PET controls performed 3- to 6-months post-treatment, confirmed the disappearance of the metabolic stigma. CONCLUSION 18FDG PET may show an increased glucose metabolism in asymptomatic extracranial vessels locations of Horton's arterities. If these observations are confirmed on controlled trials, PET could be particularly useful for non-invasive diagnosing, staging and monitoring atypical clinical forms of Horton's disease. The metabolic imaging could also contribute to a better understanding of the pathogenesis of GCA.
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Affiliation(s)
- T Belhocine
- Service de médecine nucléaire, CHU de Liège, Sart Tilman, Bât.35, 4000 Liège, Belgique.
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Jamar F, Houssiau FA, Devogelaer JP, Chapman PT, Haskard DO, Beaujean V, Beckers C, Manicourt DH, Peters AM. Scintigraphy using a technetium 99m-labelled anti-E-selectin Fab fragment in rheumatoid arthritis. Rheumatology (Oxford) 2002; 41:53-61. [PMID: 11792880 DOI: 10.1093/rheumatology/41.1.53] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.0] [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: 11/13/2022] Open
Abstract
OBJECTIVE We previously described a novel radiolabelled monoclonal antibody (1.2B6), which reacts with porcine E-selectin, for targeting activated endothelium as a means of imaging inflammatory disorders, and presented initial clinical work based on (111)In-labelled antibody. The aim of the present study was to evaluate a Fab fragment of 1.2B6 labelled with (99m)Tc in patients with rheumatoid arthritis (RA) by comparison with (i) (111)In-labelled 1.2B6 F(ab')(2) and (ii) conventional bone scanning. METHODS (99m)Tc-1.2B6-Fab ( approximately 440 MBq) and (111)In-1.2B6-F(ab')(2) ( approximately 27 MBq) were compared in 10 patients using a double-isotope protocol. Images were obtained 4 and 20-24 h after injection. Two normal volunteers were also imaged. In a separate group of 16 patients, (99m)Tc-1.2B6-Fab and (99m)Tc-oxidronate ((99m)Tc-HDP) ( approximately 740 MBq) were compared on the basis of visual and semi-quantitative analysis of joint uptake (joint/soft tissue ratios) 4 h after injection. The respective biodistributions and blood clearances of the two 1.2B6 fragments were also compared. RESULTS Image contrast was slightly better with (99m)Tc-Fab at 4 h but equal for the two tracers at 24 h. Diagnostic accuracy, taking joint tenderness or swelling as the clinical endpoint, was 76% for both fragments at 24 h. Plasma clearance of (99m)Tc-Fab was faster than that of (111)In-F(ab')(2) (t(1/2) 142 vs 421 min; P<0.0001). (99m)Tc-Fab appeared somewhat unstable in vivo, as shown by activity in the thyroid gland and bowel. The diagnostic accuracy of (99m)Tc-Fab was 88%, higher than that of (99m)Tc-HDP (57%) as a result of the low specificity of the latter in RA. Receiver operating characteristic (ROC) curve analysis using joint/soft tissue ratios as a variable cut-off showed that (99m)Tc-Fab discriminates better than (99m)Tc-HDP between actively inflamed and silent joints (Z=4.72; P<0.0001). No uptake of (99m)Tc-Fab was observed by inactive or normal joints, whereas (99m)Tc-HDP was taken up by all joints to a variable degree, making the decision as to whether a particular joint is actively involved or chronically damaged very difficult. CONCLUSION (99m)Tc-anti-E-selectin-Fab scintigraphy can be used successfully to image synovitis with better specificity than (99m)Tc-HDP bone scanning. The advantages over (111)In-1.2B6-F(ab')(2) are easier availability of the radionuclide, improved physical properties and optimal imaging 4 h after injection.
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Affiliation(s)
- F Jamar
- Centre of Nuclear Medicine, University of Louvain Medical School, Brussels, Belgium
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Abstract
Electron microscopic examination of detergent-extracted Toxoplasma tachyzoites reveals the presence of a mechanically stable cytoskeletal structure associated with the pellicle of this parasite. This structure, composed of interwoven 8-10 nm filaments, is associated with the cytoplasmic face of the pellicle and surrounds the microtubule-based cytoskeleton. Two protein components of this network, TgIMC1 and TgIMC2, were identified. Both are novel proteins, but have a resemblance to mammalian filament proteins in that they are predicted to have extended, coiled-coil domains. TgIMC1 is also homologous to articulins, the major components of the membrane skeleton of algae and free-living protists. A homologue of TgIMC1 in the related malaria parasite Plasmodium falciparum was also identified suggesting the presence of structurally similar membrane skeletons in all apicomplexan parasites. We suggest that the subpellicular network, formed by TgIMC1 and 2 in Toxoplasma gondii and related parasites, plays a role in the determination of cell shape and is a source of mechanical strength.
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Affiliation(s)
- T Mann
- Department of Cell Biology, University of Alabama at Birmingham, BBRB 540, 845 19th Street South, 35294-2170, Birmingham, AL, USA
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Kieschnick H, Wakefield T, Narducci CA, Beckers C. Toxoplasma gondii attachment to host cells is regulated by a calmodulin-like domain protein kinase. J Biol Chem 2001; 276:12369-77. [PMID: 11154702 DOI: 10.1074/jbc.m011045200] [Citation(s) in RCA: 118] [Impact Index Per Article: 5.1] [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: 11/06/2022] Open
Abstract
The role of calcium-dependent protein kinases in the invasion of Toxoplasma gondii into its animal host cells was analyzed. KT5926, an inhibitor of calcium-dependent protein kinases in other systems, is known to block the motility of Toxoplasma tachyzoites and their attachment to host cells. In vivo, KT5926 blocks the phosphorylation of only three parasite proteins, and in parasite extracts only a single KT5926-sensitive protein kinase activity was detected. This activity was calcium-dependent but did not require calmodulin. In a search for calcium-dependent protein kinases in Toxoplasma, two members of the class of calmodulin-like domain protein kinases (CDPKs) were detected. TgCDPK2 was only expressed at the mRNA level in tachyzoites, but no protein was detected. TgCDPK1 protein was expressed in Toxoplasma tachyzoites and cofractionated precisely with the peak of KT5926-sensitive protein kinase activity. TgCDPK1 kinase activity was calcium-dependent but did not require calmodulin or phospholipids. TgCDPK1 was found to be inhibited effectively by KT5926 at concentrations that block parasite attachment to host cells. In vitro, TgCDPK1 phosphorylated three parasite proteins that migrated identical to the three KT5926-sensitive phosphoproteins detected in vivo. Based on these observations, a central role is suggested for TgCDPK1 in regulating Toxoplasma motility and host cell invasion.
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Affiliation(s)
- H Kieschnick
- Division of Geographic Medicine, Department of Cell Biology, University of Alabama at Birmingham, Birmingham, Alabama 35294, USA
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Horak F, Unkauf M, Beckers C, Mittermaier EM. Efficacy and tolerability of intranasally applied dimetindene maleate solution versus placebo in the treatment of seasonal allergic rhinitis. Arzneimittelforschung 2000; 50:1099-105. [PMID: 11190775 DOI: 10.1055/s-0031-1300341] [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: 10/28/2022]
Abstract
The aim of this study was to investigate the efficacy and tolerability of a 0.1% dimetindene maleate spray (Fenistil Nasal Dosierspray) compared to placebo when applied intranasally. Dimetindene (dimetindene maleate, CAS 3614-69-5, DMM) is a very potent and well established H1-receptor antagonist. A total of 36 asymptomatic patients (17 female, 19 male), suffering from seasonal allergic rhinitis from grass pollen, were randomly assigned to treatment with matching topicalnasal sprays with either dimetindene maleate 0.1% or placebo as control in a double-blind, randomised, cross-over-design, with 2 weeks wash-out periods between. The trial period was chosen in a pollen-free time from 20th October to 5th November 1998 to guarantee asymptomatic patients. The patients being allergic to grass pollen, verified by positive case history, positive skin prick test and positive nasal provocation test, were challenged under controlled conditions with purified airborne grass pollen in the Vienna Challenge Chamber. The nasal spray were applied as single doses (1 puff = 0.14 ml of the respective solution with or without 0.14 mg dimetindene maleate) in the evening before at 7.30 p.m. and in the morning at 7.30 a.m. to each nostril exactly 15 min before the onset of allergen provocation. The dosage scheme relates to a daily dose of 0.56 mg DMM in the active treatment group. Subjective nasal and ocular symptoms were measured on-line in time intervals of 30 min during the 4 h allergen provocation. The statistical analysis was a priori sequentially ordered to account for multiple testing and keep the 5% level of significance. All measured primary criteria, Total Nasal Symptom Score (p < 0.0001) calculated from the three single symptoms running of the nose (p = 0.0032) sneezing stimulus (p < 0.0001) and nasal itching (p < 0.0001), as well nasal secretion (p = 0.0031), resulted consistently in a statistically significant and clinically relevant superiority of 0.1% DMM compared to placebo. The same superior treatment effect was observed for all the other criteria, despite the nasal flow, but including the ocular variables. This can be interpreted as a positive efficacy also in secondary allergic conjunctivitis. No systemic or topical adverse events were reported. The results of the study demonstrate that 0.1% DMM as nasal spray is an efficient and safe application form for patients suffering from seasonal allergic rhinitis.
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Affiliation(s)
- F Horak
- Universitäts-Klinik für Hals-Nasan-Ohrenheilkunde, Allgemeines Krankenhaus der Stadt Wien, Vienna, Austria
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19
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Englisch W, Beckers C, Unkauf M, Ruepp M, Zinserling V. Efficacy of Artichoke dry extract in patients with hyperlipoproteinemia. Arzneimittelforschung 2000; 50:260-5. [PMID: 10758778 DOI: 10.1055/s-0031-1300196] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
Efficacy and tolerability of artichoke dry extract (drug/extract ratio 25-35:1, aquous extract, CY450) as coated tablets containing 450 mg extract (tradename: Valverde Artischocke bei Verdauungsbeschwerden) was investigated in the treatment of hyperlipoproteinemia and compared with placebo. 143 adult patients with initial total cholesterol of > 7.3 mmol/l (> 280 mg/dl) were included in a double blind, randomized, placebo controlled, multi-center clinical trial. Patients received 1,800 mg artichoke dry extract per day or placebo over 6 weeks. Changes of total cholesterol and LDL-cholesterol from baseline to the end of treatment showed a statistically significant superiority (p = 0.0001) of artichoke dry extract over placebo. The decrease of total cholesterol in the CY450 group was 18.5% compared to 8.6% in the placebo group. LDL-cholesterol decrease in the CY450 group was 22.9% and 6.3% for placebo. LDL/HDL ratio showed a decrease of 20.2% in the CY450 group and 7.2% in the placebo group. There were no drug related adverse events during this study indicating an excellent tolerability of artichoke dry extract. This prospective study could contribute clear evidence to recommend artichoke dry extract CY450 for treating hyperlipoproteinemia and, thus, prevention of atherosclerosis and coronary heart disease.
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Affiliation(s)
- W Englisch
- Novartis Consumer Health GmbH, Munich, Germany
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20
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Beckers C. 131I therapy of toxic and non-toxic goiters. Q J Nucl Med 1999; 43:291-6. [PMID: 10731779] [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: 02/15/2023]
Abstract
For more than 50 years, 131I has been recognized as an effective tool for controlling thyroid hyperplasia and hyperactivity. The fixed dose administration is the simplest method with doses of 111-370 MBq (3 to 10 mCi) 131I being administered. More sophisticated methods aiming to deliver a well-defined amount of 131I per gram of thyroid tissue are handicapped by problems related to the evaluation of the goiter size and the prediction of the sensitivity of thyroid cells to radiation. The use of 131I in nontoxic multinodular goiter is to be reserved for specific situations.
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Affiliation(s)
- C Beckers
- Centre of Nuclear Medicine, University of Louvain Medical School, Brussels, Belgium.
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21
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Beckers C. Radioiodine and thyroid-associated ophthalmopathy: from the myth to the reality. J Endocrinol Invest 1999; 22:705-7. [PMID: 10595836 DOI: 10.1007/bf03343634] [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] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- C Beckers
- Centre de Médecine Nucléaire, University of Louvain Medical School, Brussels, Belgium
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22
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Roelants V, Beckers C. 99mTc-MIBI in differentiated thyroid carcinoma. J Nucl Med 1999; 40:1769. [PMID: 10520721] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/14/2023] Open
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23
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van den Hove MF, Beckers C, Devlieger H, de Zegher F, De Nayer P. Hormone synthesis and storage in the thyroid of human preterm and term newborns: effect of thyroxine treatment. Biochimie 1999; 81:563-70. [PMID: 10403191 DOI: 10.1016/s0300-9084(99)80111-4] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.4] [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: 11/24/2022]
Abstract
Iodine and thyroglobulin concentrations, as well as iodine, T3, T4 and sialic acid contents of thyroglobulin, were measured in thyroid glands collected postmortem from 42 human premature or term newborns and infants. Three groups were considered: very preterm newborns (24-32 postmenstrual weeks, < 5 days postnatal life), preterm and term newborns (34-41 postmenstrual weeks, < 5 days postnatal life) and infants (born at term, postnatal age 1-8 months). Five very preterm and seven preterm newborns received a daily dose of 10 microg/kg L-T4 for at least 3 days. Thyroid weight and sialic acid content of thyroglobulin progressed with maturation. Intrathyroidal concentrations of iodine and thyroglobulin did not increase significantly before the 42nd week of postmenstrual age. The level of thyroglobulin iodination increased during the postnatal life, except in the very preterm neonates. T4 and T3 content of thyroglobulin was directly proportional to its degree of iodination and positively related to its sialic acid content. L-T4 treatment of preterm newborns increased thyroglobulin iodination and T4-T3 content, without increasing thyroglobulin concentration in the thyroid. It was concluded that the storage of thyroglobulin and iodine in the thyroid develops around term birth. This, associated with the resulting rapid theoretical turnover of the intrathyroidal pool of T4 in Tg, could be an important factor of increased risk of neonatal hypothyroxinemia in the premature infants. The L-T4 treatment of preterm newborns does not accelerate the maturational process of the thyroid gland.
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Affiliation(s)
- M F van den Hove
- Christian-de-Duve Institute of Cellular Pathology (ICP), Faculté de Médecine, Université Catholique de Louvain, Brussels, Belgium
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Schaffler K, Beckers C, Unkauf M, Kyrein HJ. Dimethindene maleate in the treatment of sunburn. A double-blind, placebo-controlled pilot study. Arzneimittelforschung 1999; 49:374-9. [PMID: 10337458 DOI: 10.1055/s-0031-1300429] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
The efficacy of topical dimethindene maleate (DMM, CAS 31614-69-5, Fenistil Gel) in the treatment of sunburn was evaluated in a placebo-controlled, 1-period crossover trial in 24 healthy volunteers. An UV-erythema (sunburn) of a well-defined intensity and extent was experimentally induced on three different skin test-areas by means of UV-A/B irradiation with three times the minimal erythema dose (MED). About 24 h after irradiation, one skin test-area was subjected to a 1-h occlusive treatment with DMM gel, the second test area was subjected to treatment with a placebo gel and the third one remained untreated. As objective-quantitative indicators of tenderness, a key symptom of sunburn, sensory and pain thresholds to CO2-Laser stimulation and laser somatosensory evoked potentials (SEPs) in Vertex-EEG were assessed about 1.5 h postdose. The reaction times (RTs) to painless and painful CO2-laser stimulation (sensory and pain threshold level, respectively) on the DMM-treated area were significantly longer than RTs to stimulation on the placebo-treated area. Thresholds in terms of laser energy showed no differences between the treatments. The SEP N1-amplitude on the DMM-area was markedly decreased in comparison to placebo. With regard to subjective sensations of pain, itching and tenderness assessed by means of visual analogue scales (VAS), no clinically relevant differences between treatments were observed after sole UV-irradiation. After additional laser stimulation tenderness was--objectively but not subjectively--decreased on the DMM-area versus placebo. Both gel preparations were well tolerated.
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Affiliation(s)
- K Schaffler
- IPR Phoenix International GmbH, Munich, Germany
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25
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Abstract
Absorbed doses to family members of patients treated with (131)I were measured using thermoluminescent dosimeters worn on the chest. Twenty-two patients with thyroid cancer were hospitalized for 2 d for treatment with 3,700-7,400 MBq, and 18 hyperthyroid patients were treated on an outpatient basis with 200-600 MBq. Doses were measured over periods of 15-21 d following the administration of radioiodine in 35 partners and 38 children, aged 4 mo to 25 y. These results were correlated with dose rate measurements performed with an ionization chamber, and residual thyroid uptake was assessed by scintigraphy over the same period. In the cancer group, the residual activity in thyroid remnants was less than 50 MBq in all cases at day 4 following treatment and decayed with a mean half-life of 2.2 (SD: 0.8) d. The dose measured with thermoluminescent dosimeters was lower than 0.5 mSv in all partners and children. In the hyperthyroid group, the effective half-life averaged 6.2 (SD: 1.2) d. The median of the doses measured in partners and children were 1.04 mSv (range: 0.05-5.2) and 0.13 mSv (range: 0.04-3.1), respectively. Fifteen children (88%) received less than the dose constraint of 0.5 mSv. The ICRP recommend an annual limit of 1 mSv for the members of the public. In addition, dose constraints (for example: 0.5 mSv) should be complied with whenever possible. The recommended dose limits are generally well met among family members of patients treated with 1311 for cancer. The higher doses measured in hyperthyroid patients, compared to thyroid cancer patients, relate to a higher (131)I retention by the gland and justify more extended and stringent restriction periods, based on residual thyroid activity.
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Affiliation(s)
- I Mathieu
- Center of Nuclear Medicine, University of Louvain Medical School, Brussels, Belgium
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Otmani A, Tribouilloy C, Leborgne L, Vermes E, Trojette F, Beckers C, Remond A, Fonroget J, Rey JL, Lesbre JP. [Diagnostic value of echocardiography and thoracic spiral CT angiography in the diagnosis of acute pulmonary embolism]. Ann Cardiol Angeiol (Paris) 1998; 47:707-15. [PMID: 9922847] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/10/2023]
Abstract
The objective of this study was to define the limits of echocardiography and to evaluate thoracic spiral CT angiography (TSCTA) for the diagnosis of pulmonary embolism (PE). One hundred twelve consecutive patients, hospitalised for suspected PE, were included in this prospective study. All were investigated by pulmonary ventilation-perfusion scintigraphy (Sc) and 50 had a high probability of PE on this examination. Sc was normal in 22 patients. Forty patients were excluded because of an intermediate probability. In 50 patients with PE confirmed on Sc, transthoracic echocardiography (TTE) showed only indirect evidence of PE (intracavitary thrombus in 4% of cases). TSCTA demonstrated PE in 82% of cases and did not show any thrombus image when Sc was normal. Its negative predictive value was therefore 70% and its positive predictive value was 100%. Its sensitivity varied according to degree of perfusion defect (96% in the case of lobar lesion, 66% in the case of segmental lesion and 16% for a subsegmental lesion). Multidimensional transoesophageal echocardiography (TOE), performed in 37 of the 50 patients with PE, only revealed thrombi in the pulmonary tree in 3 patients (8%), all presenting severe PE. No thrombus was visualized on TOE in patients with non-serious PE. All thrombi observed on TOE were also demonstrated by TSCTA. In conclusion, TTE usually provides only indirect signs of PE. TOE has a poor diagnostic sensitivity for PE. TSCTA has a better sensitivity than TOE for the detection of thrombi in the pulmonary artery trunk and proximal centimetres of its two branches, but normal CT angiography cannot exclude a distal PE.
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Affiliation(s)
- A Otmani
- Département de Cardiologie, Hôpital sud, Amiens
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Saginario C, Sterling H, Beckers C, Kobayashi R, Solimena M, Ullu E, Vignery A. MFR, a putative receptor mediating the fusion of macrophages. Mol Cell Biol 1998; 18:6213-23. [PMID: 9774638 PMCID: PMC109208 DOI: 10.1128/mcb.18.11.6213] [Citation(s) in RCA: 127] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/1998] [Accepted: 07/31/1998] [Indexed: 11/20/2022] Open
Abstract
We had previously identified a macrophage surface protein whose expression is highly induced, transient, and specific, as it is restricted to actively fusing macrophages in vitro and in vivo. This protein is recognized by monoclonal antibodies that block macrophage fusion. We have now purified this protein and cloned its corresponding cDNA. This protein belongs to the superfamily of immunoglobulins and is similar to immune antigen receptors such as the T-cell receptor, B-cell receptor, and viral receptors such as CD4. We have therefore named this protein macrophage fusion receptor (MFR). We show that the extracellular domain of MFR prevents fusion of macrophages in vitro and therefore propose that MFR belongs to the fusion machinery of macrophages. MFR is identical to SHPS-1 and BIT and is a homologue of P84, SIRPalpha, and MyD-1, all of which have been recently cloned and implicated in cell signaling and cell-cell interaction events.
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Affiliation(s)
- C Saginario
- Department of Cell Biology, Yale University School of Medicine, New Haven, Connecticut, USA
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Roelants V, Goulios C, Beckers C, Jamar F. Iodine-131-MIBG scintigraphy in adults: interpretation revisited? J Nucl Med 1998; 39:1007-12. [PMID: 9627334] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
UNLABELLED Iodine-131-metaiodobenzylguanidine (MIBG) scintigraphy is a reliable method used to diagnose pheochromocytoma. Although the adrenal medulla usually is not visualized, faint uptake can be observed in 16% of the patients 48-72 hr after injection of 18.5-37 MBq 131I-MIBG. We recently observed an increase in the frequency of visualization of the adrenal medulla in patients injected with 74 MBq 131I-MIBG. Therefore, we retrospectively evaluated the pattern of uptake and potential changes between 1984 and 1994. METHODS Scintigraphic data from 103 patients referred for suspected pheochromocytoma were reviewed randomly. Data from 19 patients with medullary thyroid carcinoma were analyzed separately. Patients were injected with 74 MBq 131I-MIBG and imaged at 24 hr postinjection, 48 hr postinjection, or both. Adrenal uptake was scored visually as 0 (no visible uptake) and 1 (uptake just visible) to 4 (most intense activity in the picture). Semiquantitative indicies were evaluated for discriminating between normal adrenal medullae and pheochromocytomas. Twenty-seven pheochromocytomas were surgically proven in 25 patients. RESULTS A visual score > or =3 was noted in 81% and 90% of the pheochromocytomas at 24 hr and 48 hr postinjection, respectively. From 1984 to 1988, 16% and 31% of adrenal medullae were seen at 24 and 48 hr postinjection, respectively, whereas from 1989 to 1994, 56% and 73% were visualized at 24 and 48 hr postinjection, respectively. Before 1989, the best cutoff criterion to identify a pheochromocytoma, determined from receiver operating characteristic curve analysis, was a score > or =1 at 24 hr and > or =3 at 48 hr postinjection, with a sensitivity and specificity of 92% and 84% at 24 hr and 92% and 99% at 48 hr postinjection. From 1989, the best cutoff was a score > or =3 at both imaging sessions, with a sensitivity and specificity of 82% and 100% at 24 hr and 100% and 97% at 48 hr postinjection. Among the semiquantitative indicies, the adrenal-to-liver and adrenal-to-heart ratios were the best discriminators between normal and pathological adrenals. They were, however, of little use because of the overlap between normal adrenal medullae and pheochromocytomas. CONCLUSION The high rate of visualization of the normal adrenal medulla in this study was related to the larger-than-usual injected dose (74 MBq). Over recent years, however, this rate has been increasing, possibly because of the increased specific activity of 31I-MIBG. Adequate interpretation should take into account that a faint or definite uptake may be visible in more than 50% of normal adrenal medullae.
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Affiliation(s)
- V Roelants
- Center of Nuclear Medicine, University of Louvain Medical School, Brussels, Belgium
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29
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Silverman JA, Qi H, Riehl A, Beckers C, Nakaar V, Joiner KA. Induced activation of the Toxoplasma gondii nucleoside triphosphate hydrolase leads to depletion of host cell ATP levels and rapid exit of intracellular parasites from infected cells. J Biol Chem 1998; 273:12352-9. [PMID: 9575188 DOI: 10.1074/jbc.273.20.12352] [Citation(s) in RCA: 64] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The nucleoside triphosphate hydrolase of Toxoplasma gondii is a potent apyrase. The protein is synthesized in large amounts and transported through the secretory pathway of the parasite and into the vacuolar space in an oxidized and thereby enzymatically inactive form. Complete activation of the purified enzyme is known to require dithiols (e.g. DTT); subcellular fractionation demonstrates that little if any (<5%) of the enzyme in the vacuolar space is active in the absence of DTT. Both native and epitope-tagged nucleoside triphosphate hydrolase (NTPase) were partially activated during immunoprecipitation, precluding precise assessment of enzyme activity in the vacuolar space but suggesting that protein-protein interactions may trigger activation. When infected cells were treated with DTT, the NTPase was activated in a dose-response fashion, as assessed by migration on SDS-polyacrylamide gel electrophoresis and by an increase in enzymatic activity. After activation, enzyme activity decreased with time in the presence of DTT; this inactivation was slowed by the presence of excess ATP. A rapid fall in host cell ATP was accompanied by an abrupt exit of parasites from cells. These results demonstrate that the oxidation/reduction status of the NTPase, the only parasite dense granule protein that contains disulfide bonds, is tightly controlled within the vacuolar space and may influence parasite exit from cells.
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Affiliation(s)
- J A Silverman
- Section of Infectious Diseases, Yale University School of Medicine, New Haven, Connecticut 06520-8022, USA
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Jamar F, Leners N, Beckers C, Manicourt DH. 99mTc-labelled immunoglobulin scintigraphy in arthritis: an analysis of synovial fluid activity. Scand J Clin Lab Invest 1997; 57:621-8. [PMID: 9397494 DOI: 10.3109/00365519709055286] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The distribution of 99mTc-labelled human polyclonal non-specific immunoglobulin G (HIG) in the synovial fluid was studied in 14 patients with rheumatoid and non-rheumatoid arthritides. Analysis included the determination of the total activity per ml synovial fluid 6 h post-injection (p.i.) of the tracer as well as of the protein- and cell-bound fractions. At 6 h p.i., > 60% of the injected dose remained in plasma as protein-bound radioactivity. Values in the synovial fluid ranged between 0.001 and 0.009% of the injected dose per ml. Importantly, the synovial fluid to plasma ratio was consistently < 1 (range: 0.09-0.43), which is in the range of ratios observed for endogenous proteins in vivo. Similar values were obtained in samples of synovial tissue obtained at surgery in two patients. These data are consistent with the hypothesis that labelled HIG accumulates in the extracellular fluid (both within the synovial tissue and fluid) by non-specific mechanisms (such as increased blood pool and capillary permeability) and does not equilibrate with circulating plasma proteins in accordance with basic knowledge of synovial physiology. In addition, it was found that most of the activity remained bound to the proteins in the fluid and that cell-binding occurred to a very low degree that cannot be considered an important mechanism of uptake of this radiolabelled agent in vivo. These results provide the first evidence in an in vivo human setting that radiolabelled HIG accumulates mainly by non-specific mechanisms in inflamed joints.
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Affiliation(s)
- F Jamar
- Centre of Nuclear Medicine, University of Louvain Medical School, Brussels, Belgium
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Roelants V, Nayer PD, Bouckaert A, Beckers C. The predictive value of serum thyroglobulin in the follow-up of differentiated thyroid cancer. Eur J Nucl Med 1997; 24:722-7. [PMID: 9211756 DOI: 10.1007/bf00879658] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
A strict and careful strategy has to be adopted to cure thyroid cancer. Diagnostic iodine-131 whole-body scan (WBS) and serum thyroglobulin (Tg) are important tools to detect thyroid remnants after thyroidectomy and radioiodine therapy. The aim of this retrospective study was to compare the relative sensitivity of WBS and Tg in the detection of thyroid remnants or metastases and to evaluate the predictive value of Tg in the clinical and scintigraphic course of the disease. Ninety-three patients were followed up after total thyroidectomy and the administration 4-6 weeks later of an ablative dose of 100 or 150 mCi 131I. Eighty-five percent of the patients were free of regional or distant metastases. The follow-up scheme included clinical examination of the patient followed by WBS, Tg, thyroid-stimulating hormone and free thyroxine measurements performed 4 weeks after thyroxine withdrawal and the observance of a low-iodine diet for at least 1 week. WBS (+) patients received a 100- or 150-mCi therapeutic dose of 131I. All patients were further followed up in the same way every 6 months until both WBS and Tg became negative, and thereafter at 1-, 2- and 4-year intervals. Six months after the postoperative radioiodine treatment (first visit), the sensitivity of WBS and Tg was 87% and 26% respectively. Among patients who were WBS(+) at the first visit, 95% of those who were Tg(-) and 47% of those who were Tg(+) had become disease-free at a median of 4 years after surgery (chi2=13.6; P<0.05). Patients whose tests were both positive required more radioiodine to be cured (335+/-90 vs 250+/-95 mCi; P<0.05). Our data indicate that in early diagnosed thyroid cancer, serum Tg measured 6 months after the postoperative 131I ablative dose is less sensitive than WBS for the demonstration of persistence of residual thyroid tissue but provides predictive information on the disease course. WBS(+) and Tg(-) patients are cured earlier and with less radioiodine than those who remain Tg(+).
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Affiliation(s)
- V Roelants
- Center of Nuclear Medicine, University of Louvain Medical School, Brussels, Belgium
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Abstract
The European Union recently adopted the main International Commission on Radiological Protection (ICRP) recommendations on radiation protection. The annual limit for the members of the public on continuous exposure is 1 mSv/year, with a constraint dose of 0.3 mSv. Such regulation may raise a number of practical problems for 131I-treated patients, particularly those receiving radioiodine as outpatients. The radiation exposure evaluated on the basis of dose rate assessments and dose occupancy usually leads to results significantly higher than those obtained by direct measurements with thermoluminescent dosimeters carried for 2-3 weeks by the family members of the patient. From these direct measurements, it appears that reasonable instructions given to 131I-treated patients allow us to respond positively to the ICRP recommendations without disturbing too excessively the patient's daily life. Educational action remains essential in radiation protection.
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Affiliation(s)
- C Beckers
- Centre de Médecine Nucléaire, University of Louvain Medical School, Brussels, Belgium
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Stoffel M, Jamar F, Donckier J, Hainaut P, Decoster P, Beckers C, Pauwels S. Increased uptake of indium-111 pentetreotide up to 10 years after external thoracic irradiation: report of two cases. Eur J Nucl Med 1996; 23:723-6. [PMID: 8662109 DOI: 10.1007/bf00834537] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Indium-111 pentetreotide scintigraphy was performed in two patients for the localization of recurrent medullary thyroid carcinoma treated by surgery and external radiotherapy 1 and 10 years earlier. A marked uptake of the radiopharmaceutical was demonstrated in the lung areas that had been irradiated. These cases strongly suggest that this uptake is related to pulmonary fibrosis, a well-known complication of radiotherapy, even long after the irradiation. Therefore, attention must be paid to the avoidance of false-positive interpretation of somatostatin receptor scintigraphy in patients previously treated by radiotherapy.
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Affiliation(s)
- M Stoffel
- Department of Nuclear Medicine, University of Louvain (UCL), Mont-Godinne, Belgium
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35
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Beckers C, Alexander WD, Burger A, Lazarus J, Krenning E, Schlumberger M, Williams D. 131I therapy for thyrotoxicosis towards 2000. Eur J Nucl Med Mol Imaging 1996. [DOI: 10.1007/bf01247386] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Stoffel M, Jamar F, Van Nerom C, Verbruggen A, Besse T, Squifflet JP, Beckers C. Technetium-99m L,L-ethylenedicysteine clearance and correlation with iodine-125 orthoiodohippurate for the determination of effective renal plasma flow. Eur J Nucl Med 1996; 23:365-70. [PMID: 8612654 DOI: 10.1007/bf01247362] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Technetium-99m L,L-ethylenedicysteine (99mTc-L,L-EC) is a new renal tubular tracer that allows the determination of the effective renal plasma flow (ERPF). The aim of this study was to derive simplified methods for the estimation of 99mTc-L,L-EC clearance using one or two plasma samples after bolus injection. Fifty-nine multiple plasma dual-tracer samples (nine samples from 5 to 120 min after injection) were obtained after injection of kit-formulated 99mTc-L,L-EC and iodine-125 orthoiodohippurate (OIH). The studies were performed in 25 stable and 24 unstable transplant recipients, in five patients with renal insufficiency (four on chronic haemodialysis) and in five normal volunteers. This allowed a wide range of renal function values to be covered, with ERPF (estimated by OIH clearance) ranging from 25.4 to 604.0 ml/min. The reference 99mTc-L,L-EC clearance, as calculated from the multisample model, could be estimated from two samples at 15 and 90 min with an error of 11.3 ml/min and from one sample at 90 min with an error of 17.8 ml/min. Using appropriate linear regression analysis, ERPF could be estimated by the two- and one-sample 99mTc-L,L-EC clearance with an error of 24.2 and 22.8 ml/min, respectively. In conclusion, 99mTc-L,L-EC clearance can be accurately estimated by simplified one- or two-sample methods. Moreover, these methods can be used to estimate ERPF with an error that remains acceptable for clinical purposes.
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Affiliation(s)
- M Stoffel
- Centre of Nuclear Medicine, University of Louvain (UCL), Brussels, Belgium
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Jamitzky T, Lange O, Reinartz J, Beckers C, Emde H, Scheef W. PP-8-31 Intra-arterial liver chemoinfusion in patients with metastatic breast cancer. Eur J Cancer 1996. [DOI: 10.1016/0959-8049(96)84264-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Jamar F, Manicourt DH, Leners N, Vanden Berghe M, Beckers C. Evaluation of disease activity in rheumatoid arthritis and other arthritides using 99mtechnetium labeled nonspecific human immunoglobulin. J Rheumatol 1995; 22:850-4. [PMID: 8587071] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
OBJECTIVE To determine the usefulness of 99mtechnetium (99mTc) immunoglobulin scintigraphy (99mTc IgG) in rheumatoid arthritis (RA) and in other arthritides. METHODS Scintigraphic scores were compared with the Ritchie index and biochemical variables of disease activity. RESULTS In RA, scintigraphic scores were reproducible and seemed to perform better than clinical scores. Moreover, the scores of synovial uptake correlated significantly with systemic variables of inflammation. Other inflammatory arthritides also disclosed uptake of 99mTc IgG but noninflammatory joints did not. CONCLUSION Although nonspecific for RA, 99mTc IgG scintigraphy is a reliable tool to evaluate the degree and extent of joint inflammation.
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Affiliation(s)
- F Jamar
- Center of Nuclear Medicine, University of Louvain Medical School, Brussels, Belgium
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39
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Jamar F, Topcuoglu R, Cauwe F, De Coster P, Roelants V, Beckers C, Wijns W, Melin JA. Exercise gated planar myocardial perfusion imaging using technetium-99m sestamibi for the diagnosis of coronary artery disease: an alternative to exercise tomographic imaging. Eur J Nucl Med 1995; 22:40-8. [PMID: 7698154 DOI: 10.1007/bf00997246] [Citation(s) in RCA: 3] [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: 01/26/2023]
Abstract
Single-photon emission tomography (SPET) using technetium-99m labelled myocardial tracers (e.g. 99mTc-sestamibi) has become one of the most popular myocardial imaging methods for the diagnosis of coronary artery disease (CAD). This prospective study was designed to evaluate the diagnostic performance of 99mTc-sestamibi exercise gated planar myocardial imaging by comparison with both visual and quantitative analyses of SPET. The study was conducted in 115 consecutive patients with known or suspected CAD, including 54 patients with a previous myocardial infarction (MI), referred for exercise testing prior to coronary angiography. Multi-gated planar imaging and SPET were performed after bicycle exercise. The end-diastolic (ED) and SPET images were visually scored (SVi). Myocardial uptake was quantitated on SPET slices using maximum count circumferential profiles (SQu) and defect extent was measured by comparison with gender-matched data sets obtained from 27 controls (< 5% likelihood of CAD). CAD was defined as coronary artery stenosis > 50% and/or regional wall motion abnormality. The cut-off criteria for positivity of the three procedures were determined from receiver operating characteristic (ROC) curves derived from the data of patients without previous MI. The area under the ROC curves was similar for ED, SVi and SQu. This was confirmed by the analysis of sensitivity performed using the ROC curve-derived cut-off criteria, in patients with or without previous MI. SVi was more sensitive than ED in identifying the diseased vessel(s) (ED: 41% vs SVi: 80%; P < 0.0005) but ED was more specific in this respect (ED: 79% vs SVi: 61%; P < 0.0005).(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- F Jamar
- Centre of Nuclear Medicine, University of Louvain Medical School, Brussels, Belgium
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40
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Stoffel M, Jamar F, Van Nerom C, Verbruggen A, Mourad M, Leners N, Squifflet JP, Beckers C. Evaluation of technetium-99m-L,L-EC in renal transplant recipients: a comparative study with technetium-99m-MAG3 and iodine-125-OIH. J Nucl Med 1994; 35:1951-8. [PMID: 7989976] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
UNLABELLED The clinical usefulness of kit-formulated 99mTc-L,L-EC, a new renal tubular tracer agent based on a diaminodithiol ligand was evaluated in a large population of renal transplant recipients. METHODS Fifty patients with transplants were studied. Five patients with renal insufficiency and five normal volunteers were also included to extend the range of renal function values. The labeling efficiency of 99mTc-L,L-EC in routine conditions, i.e., without HPLC purification, and the safety of the tracer were evaluated. RESULTS The mean radiochemical purity of 99mTc-L,L-EC determined by thin-layer chromatography was 97.4%. No side effects or significant biochemical changes were observed. The clearance of 99mTc-L,L-EC and 125I-OIH ranged from 10.7 to 417.5 and from 27.6 to 602.7 ml/min/1.73 m2, respectively. The clearance of 99mTc-L,L-EC and 99mTc-MAG3 averaged respectively 71% and 52% of that of 125I-OIH. CONCLUSION The labeling procedure of kit-formulated 99mTc-L,L-EC is easy and efficient. This tracer is safe and suitable for both imaging and quantitative measurement of the renal tubular function. Technetium-99m-L,L-EC represents an excellent alternative to 99mTc-MAG3.
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Affiliation(s)
- M Stoffel
- Center of Nuclear Medicine, University of Louvain Medical School, Brussels; Belgium
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41
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Hotez P, Cappello M, Hawdon J, Beckers C, Sakanari J. Hyaluronidases of the gastrointestinal invasive nematodes Ancylostoma caninum and Anisakis simplex: possible functions in the pathogenesis of human zoonoses. J Infect Dis 1994; 170:918-26. [PMID: 7930737 DOI: 10.1093/infdis/170.4.918] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
The gastrointestinal invasive stages of two parasitic nematodes, Ancylostoma caninum and Anisakis simplex, were each found to release in vitro a hydrolytic enzyme that degrades the glycosaminoglycan hyaluronic acid. The parasite hyaluronidases were partially purified by ion-exchange chromatography and biochemically characterized. The hyaluronidase from A. caninum adult worms had a molecular weight of 65,000 and a pH optimum of 6 with activity at neutral pH, while the hyaluronidase from A. simplex larvae had a molecular weight of 40,000 and a pH optimum of 4 with no activity at neutral pH. Both parasite hyaluronidases also degraded the glycosaminoglycan chondroitin sulfate A. Cupric sulfate and high concentrations of sodium chloride were inhibitory. The nematode hyaluronidases are postulated to have a role in tissue histolysis and mucosal invasion; their distinct biochemical properties have relevance to the pathogenesis of the zoonoses anisakiasis and eosinophilic enteritis.
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Affiliation(s)
- P Hotez
- Department of Pediatrics, Yale University School of Medicine, New Haven, CT 06510
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42
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Kirchhoff R, Beckers C, Kirchhoff GM, Trinczek-Gärtner H, Petrowicz O, Reimann HJ. Increase in choleresis by means of artichoke extract. Phytomedicine 1994; 1:107-115. [PMID: 23195882 DOI: 10.1016/s0944-7113(11)80027-9] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
The choleretic action of artichoke extract [main ingredient: cynarin (1.5-di-caffeoyl-D-quinc acid)] was investigated in a randomised placebo-controlled double-blind cross-over study (pilot study) [n = 20]. The effect of the standardized, artichoke extract: Hepar SL forte (administered as a single dose: 1.92 g, by the intraduodenal route in a solution of 50 ml of water) was studied by measuring intra-duodenal bile secretion using multi-channel probes. Thirty minutes after the test-substance was administered, a 127.3% increase in bile secretion was recorded, after 60 minutes, 151.5%, and after another 60 minutes, 94.3%, each in relation to the initial value. The relevant differences for the placebo were significant to the extent of p < 0.01 and were clinically relevant. The highest increase in the case of the placebo (139.5%) was seen after 30 minutes. At 120 and 150 minutes the volume of bile secreted under the active treatment was also significantly higher than under the placebo (p < 0.05). In the placebo group, bile secretion fell below the initial level after 3 hours. An effective period of about 120-150 minutes was regarded as satisfactory to influence enzymatic digestion and the motor function of the intestine when the test substance was given postprandially. No side effects nor changes in the laboratory parameters in connection with the experiment were observed. Results indicate that artichoke extract can be recommended for the treatment of dyspepsia, especially when the cause may be attributed to dyskinesia of the bile ducts or disorder in the assimilation of fat.
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Affiliation(s)
- R Kirchhoff
- Vera-Med.-Klinik, Schulstr. 4, 79669 Zell, Germany
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43
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Granier P, Manicourt DH, Pauwels S, Nagant de Deuxchaisnes C, Beckers C. [Semi-quantitative analysis of 3-phase bone scintigraphy data in algodystrophy of the limbs]. Rev Rhum Ed Fr 1994; 61:179-88. [PMID: 7920514] [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: 01/27/2023]
Abstract
Three-phase bone scanning of the extremities (foot or hand) was performed in 40 normal subjects and in 56 patients with an unequivocal clinical diagnosis of reflex sympathetic dystrophy. Ten patients were in the "cold" or atrophic stage of the disease process, whereas 46 were in the "hot" or acute phase. The scintigraphic parameters studied were the ratios of tracer activity in the affected side over the healthy side established for blood flow (BF), blood pool (BP), early vasculo-tissular fixation (EF), and late bone fixation (LF). In the controls, blood flow, blood pool, and early fixation showed considerable interindividual variation and only the variation of late fixation remained within narrow limits. Among the patients, those at the hot stage of the disease had significantly higher values for all four parameters than those at the cold stage. The group at the cold stage did not differ from the controls except for a significantly higher late fixation value. Furthermore, among hot stage patients, 15% to 25% had normal or diminished blood flow, blood pool and early fixation values. At the cold stage of the disease, radionuclide parameters were similar in affected feet and hands, whereas at the hot stage values at the feet were double those at the hands. Finally, statistical analysis revealed that late fixation was most closely correlated with early fixation, which in turn was most close correlated with blood pool. The clinical and pathophysiological significance of these data is discussed.
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Affiliation(s)
- P Granier
- Service de Médecine Nucléaire, Hôpital Universitaire Saint-Luc, Université de Louvain, Bruxelles, Belgique
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Antoine N, Beckers C, Marcoty C, Bosseloir A, Beguin Y, Schaaf-Lafontaine N, Simar LJ. [Expression of DRC1 antigen by leukemic cells]. Rev Med Liege 1992; 47:95-9. [PMID: 1546224] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- N Antoine
- Université de Liège, Service d'Histologie humaine
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45
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Jamar F, Piret L, Wese FX, Beckers C. Influence of ureteral status on kidney washout during technetium-99m-DTPA diuresis renography in children. J Nucl Med 1992; 33:73-8. [PMID: 1731000] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
To assess the influence of the ureter on renal washout during 99mTc-DTPA diuresis renography, ureteral images were reviewed in 42 children (median age: 5 mo) referred for hydronephrosis. Sixty-minute acquisitions were obtained in hydrated patients under bladder drainage. Furosemide was injected at 30 min. An abnormal ureter was defined as an intense and continuous image of greater than 10 min. A washout index was determined on renal (KT1/2) and ureteral (UT1/2) curves. Curve patterns corresponding to normal (type I), obstructive (II) and nonobstructive (III) cases were described. Compared with the x-ray data, diuresis renography was highly sensitive (91%) and specific (98%) for detecting any abnormality. Despite an obstructive KT1/2 (greater than 20 min), no patient with an abnormal ureter underwent therapy at the ureteropelvic junction. After surgery at the lower level, hydronephrosis regressed. Our data indicate that abnormal ureter findings at diuresis renography have to be recognized before planning therapy for children with hydronephrosis.
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Affiliation(s)
- F Jamar
- Centre de Médecine Nucléaire, University of Louvain Medical School, Brussels, Belgium
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46
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Vander Borght T, Lambotte L, Pauwels S, Labar D, Beckers C, Dive C. Noninvasive measurement of liver regeneration with positron emission tomography and [2-11C]thymidine. Gastroenterology 1991; 101:794-9. [PMID: 1860641 DOI: 10.1016/0016-5085(91)90541-r] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The feasibility of liver regeneration determination with [2-11C]thymidine and positron emission tomography was investigated in partially hepatectomized rats. Serial tomographic scans were performed over a 120-minute period after injection of [2-11C]thymidine together with tritium-labeled thymidine. Within 10 minutes after injection, positron emission tomography scans showed a twofold higher hepatic uptake in regenerating than in nonregenerating livers. Time-activity curves over the liver area indicated that the maximal uptake was followed by a faster decrease of 11C radioactivity in controls than in regenerating animals, so that total 11C activity remaining in the liver at 120 minutes accounted for 68% of maximum in regenerating and only 38% in controls. Tissue distribution studies performed at 120 minutes showed that total 11C radioactivity, expressed in percent injected dose per gram, was six times higher in regenerating livers than in controls (0.62% +/- 0.07% in regenerating livers and 0.10% +/- 0.03% in nonregenerating livers; P less than 0.001) and correlated with 3H radioactivity measured in the nuclear fraction (r = 0.92; P less than 0.001). When the hepatic uptake was expressed in percent of dose per organ, the difference between both groups increased (2.31% +/- 0.23% in regenerating livers and 0.29% +/- 0.02% in nonregenerating livers; P less than 0.001) because of higher weight of regenerating livers than of nonregenerating livers (3.83 +/- 0.11 g in regenerating livers and 2.96 +/- 0.16 g in nonregenerating livers; P less than 0.001). In other organs examined, no difference in 11C radioactivity was found between the two groups of rats. These results indicated the potential usefulness of [2-11C]thymidine and positron emission tomography for noninvasive measurement of liver regeneration.
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Affiliation(s)
- T Vander Borght
- Department of Gastroenterology, University of Louvain Medical School, Brussels, Belgium
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47
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De Coster PM, Wijns W, Cauwe F, Robert A, Beckers C, Melin JA. Area-at-risk determination by technetium-99m-hexakis-2-methoxyisobutyl isonitrile in experimental reperfused myocardial infarction. Circulation 1990; 82:2152-62. [PMID: 2242539 DOI: 10.1161/01.cir.82.6.2152] [Citation(s) in RCA: 66] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
In a canine model of reperfused myocardial infarction, we tested the hypothesis that after reperfusion, technetium-99m-hexakis-2-methoxyisobutyl isonitrile (Tc-MIBI) tomographic imaging still reflects occlusion blood flow when the tracer is injected before reperfusion. Nine anesthetized dogs underwent 2 hours of coronary occlusion followed by 3 hours of reperfusion ending by being killed. Reference coronary blood flow was determined by radioactive microspheres injected during occlusion and after reperfusion. Biopsies in normal and ischemic myocardium and single photon emission computed tomography were obtained during occlusion and after reperfusion. Circumferential profiles were applied to axial slices divided into 5-degree sectors. The sectors were divided into 3 groups selected on the occlusion acquisition (normal, mildly reduced, and severely reduced) and compared with the postreperfusion acquisition. Tissular Tc-MIBI kinetics was assessed both by Tc-MIBI time-activity curves of normal and ischemic tissue obtained by biopsy and by the relative gradient between normal, ischemic, and necrotic postmortem tissue samples. In biopsy samples, Tc-MIBI content remained unchanged during occlusion and after reperfusion in normal as well as in ischemic tissue (4,662 +/- 2,237 counts/min/mg vs. 4,599 +/- 1,577 counts/min/mg in normal tissue, NS; 941 +/- 903 counts/min/mg vs. 1,087 +/- 721 counts/min/mg in ischemic tissue, NS). In postmortem tissue samples, there was a good correlation between occlusion microsphere blood flow and Tc-MIBI activity (r = 0.91). In the necrotic samples, mean normalized Tc-MIBI activity (10 +/- 17%) was slightly higher than the normalized microsphere blood flow (3 +/- 3%, p less than 0.001) but markedly lower than the normalized microsphere reperfusion blood flow (63 +/- 31%, p less than 0.001). Comparing the single photon emission computed tomographic acquisitions before and after reperfusion, Tc-MIBI activity remained unchanged in normal as well as in mildly reduced or severely reduced segments. Thus, our data are consistent with the hypothesis that Tc-MIBI traces blood flow, does not redistribute significantly despite reperfusion, and can be used for imaging the area at risk.
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Affiliation(s)
- P M De Coster
- Division of Cardiology, University of Louvain Medical School, Brussels, Belgium
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48
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Melin JA, Robert A, Luwaert R, Beckers C, Detry JM. Additional prognostic value of exercise testing and thallium-201 scintigraphy in catheterized patients without previous myocardial infarction. Int J Cardiol 1990; 27:235-43. [PMID: 2365512 DOI: 10.1016/0167-5273(90)90165-2] [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] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
To determine whether exercise testing and thallium scintigraphy provide additional prognostic information in symptomatic patients undergoing catheterization, we studied 432 consecutive male patients without a previous myocardial infarction by means of an exercise test, thallium scintigraphy and catheterization. The follow-up period was 46 +/- 24 months (from 12 to 96). Events were defined as death (27 patients), nonfatal myocardial infarction (occurring in 27 patients) or late (greater than 60 days after test) surgery or dilatation (needed in 45 patients). The 5 year survival rate was 89% and the event-free rate was 72%. History, noninvasive and invasive variables were submitted to a stepwise Cox regression analysis. By multivariate analysis, the significant variables related to death were the number of diseased vessels and exercise workload; the selected variables for all cardiac events were the number of diseased vessels; the score at thallium exercise testing and exercise workload. Among the subgroups of 337 coronary patients, the predictive variables for death were exercise workload and the number of diseased vessels. For all cardiac events, the selected variables were the number of diseased vessels, the score of defects during thallium exercise and exercise workload. Thus, in patients without a previous myocardial infarction, noninvasive variables do provide prognostic information which is not available either from the history or from catheterization.
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Affiliation(s)
- J A Melin
- Division of Cardiology, University of Louvain Medical School, Brussels, Belgium
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49
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Daumerie C, Mahieu P, Lienard JC, Beckers C. Interest of gallium hepatic scintigraphy in hepatic abscess: a case study. Acta Clin Belg 1990; 45:264-8. [PMID: 2173319 DOI: 10.1080/17843286.1990.11718096] [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: 12/30/2022]
Abstract
The interest of 67Ga-citrate scintigraphy in the diagnosis of hepatic abscess is illustrated by a study of a 56-year-old man, who was admitted to the hospital for upper abdominal pain. Ultrasound (US) and X-ray CT scan examinations suggested the presence of a liquid mass, the origin of which was unclear. Liver scintigraphy with 67Ga-citrate disclosed a lacunar zone surrounded by a rim of increased uptake, an image strongly suggestive of abscess or necrotic tumor. A US-guided needle aspiration of the hepatic mass yielded a purulent liquid, from which Streptococcus milleri were grown. This observation suggests that, despite the development of other diagnostic procedures, hepatic gallium scintigraphy still remains sometimes useful for the investigation of poorly characterized hepatic masses.
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Affiliation(s)
- C Daumerie
- Department of Nuclear Medicine, University of Louvain Medical School, Bruxelles, Belgium
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50
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Lambert M, De Nayer P, Ghysen J, Cornette C, Beckers C, van Ypersele de Strihou C. Decreased serum TBG concentration in the face of normal T4-binding capacity in patients on hemodialysis. Clin Nephrol 1989; 32:129-32. [PMID: 2507207] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Serum TBG concentrations were evaluated in 34 patients on regular hemodialysis. Mean serum TBG level measured by two different radioimmunoassays was markedly decreased (1.24 +/- 0.08 mg/dl - normal limits 1.6-2.4 mg/dl). Twenty-seven (79%) patients had values below 1.6 mg/dl, which contrasted in 21 of them with a lack of reciprocal elevation of T3RU values. By contrast, T4-binding capacity of TBG measured in 14 patients with low TBG concentration was normal, suggesting that the low TBG values were an artefact resulting from an altered immunoreactivity of the protein. In 2 patients with low TBG while on hemodialysis, TBG levels increased significantly after renal transplantation. This suggests that the "low TBG syndrome" (altered immunoreactivity in the face of normal T4-binding capacity) observed in patients on chronic hemodialysis is a consequence of uremia.
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Affiliation(s)
- M Lambert
- Department of Internal Medicine, Saint-Luc University Hospital, Louvain Medical School of Medicine, Brussels, Belgium
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