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Jin R, Fu X, Pu Y, Fu S, Liang H, Yang L, Nie Y, Ai H. Clinical translational barriers against nanoparticle-based imaging agents. Adv Drug Deliv Rev 2022; 191:114587. [PMID: 36309148 DOI: 10.1016/j.addr.2022.114587] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2022] [Revised: 09/22/2022] [Accepted: 10/20/2022] [Indexed: 01/24/2023]
Abstract
Nanoparticle based imaging agents (NIAs) have been intensively explored in bench studies. Unfortunately, only a few cases have made their ways to clinical translation. In this review, clinical trials of NIAs were investigated for understanding possible barriers behind that. First, the complexity of multifunctional NIAs is considered a main barrier because it brings uncertainty to batch-to-batch fabrication, and results in sophisticated in vivo behaviors. Second, inadequate biosafety studies slow down the translational work. Third, NIA uptake at disease sites is highly heterogeneous, and often exhibits poor targeting efficiency. Focusing on the aforementioned problems, key design parameters were analyzed including NIAs' size, composition, surface characteristics, dosage, administration route, toxicity, whole-body distribution and clearance in clinical trials. Possible strategies were suggested to overcome these barriers. Besides, regulatory guidelines as well as scale-up and reproducibility during manufacturing process were covered as they are also key factors to consider during clinical translation of NIAs.
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Affiliation(s)
- Rongrong Jin
- National Engineering Research Center for Biomaterials, Sichuan University, Chengdu 610064, China
| | - Xiaomin Fu
- National Engineering Research Center for Biomaterials, Sichuan University, Chengdu 610064, China
| | - Yiyao Pu
- National Engineering Research Center for Biomaterials, Sichuan University, Chengdu 610064, China
| | - Shengxiang Fu
- National Engineering Research Center for Biomaterials, Sichuan University, Chengdu 610064, China
| | - Hong Liang
- Department of Pharmacy, Sichuan Academy of Medical Sciences & Sichuan Provincial People's Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu 610072, China; Personalized Drug Therapy Key Laboratory of Sichuan Province, School of Medicine, University of Electronic Science and Technology of China, Chengdu 610072, China
| | - Li Yang
- National Engineering Research Center for Biomaterials, Sichuan University, Chengdu 610064, China
| | - Yu Nie
- National Engineering Research Center for Biomaterials, Sichuan University, Chengdu 610064, China.
| | - Hua Ai
- National Engineering Research Center for Biomaterials, Sichuan University, Chengdu 610064, China; Department of Radiology, West China Hospital, Sichuan University, Chengdu 610041, China.
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Hwang CH. Swallowing study using water-soluble contrast agents may increase aspiration sensitivity and antedate oral feeding without respiratory and drug complications: A STROBE-compliant prospective, observational, case-control trial. Medicine (Baltimore) 2022; 101:e29422. [PMID: 35801762 PMCID: PMC9259127 DOI: 10.1097/md.0000000000029422] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Although the modified barium swallowing study (MBSS) is considered the gold standard for assessing aspiration risk, aspiration of lipid-soluble barium can cause chemical pneumonitis or impair radiologic interpretation of the lungs. Water-soluble contrast agents (WSCAs) may avoid these complications while maintaining sensitivity on aspiration. This prospective, observational, case-control cohort trial evaluated all patients >3 years old referred for swallowing study from September 2015 to November 2017. Repeat evaluations of individuals were excluded. High-risk patients were evaluated by WSCA (iohexol)-based swallowing study (WSS) and others by MBSS. The study included 829 evaluations of 762 patients. After excluding 74 evaluations, 365 WSSs and 390 MBSSs were performed. The most frequent underlying condition was brain lesion, followed by aspiration pneumonia. Aspiration occurred more frequently in WSS (147 patients: 40.3%) than in MBSS (36 patients: 9.2%) (P = .00). However, neither aspiration volume (6.72 cc [3.09-10.35] vs 5.53 cc [2.21-8.85]) nor radiographic alterations differed between the 2 groups (P > .05). Moreover, the swallowed (16.62 cc [8.45-24.79]) and aspirated amounts of iohexol were not correlated with radiologic changes or deterioration (P > .05). Switching to oral feeding following WSS was more frequent (164 patients: 44.9%), whereas aspiration pneumonia was not (P = .00). WSS did not prolong the interval to patient discharge (P = .06) or induce an allergic reaction or chemotoxicity over 1 week. The absence of aspiration-induced complications and adverse drug effects suggests that, compared with MBSS, WSS may increase aspiration sensitivity and early switching to oral feeding.
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Affiliation(s)
- Chang Ho Hwang
- Department of Physical and Rehabilitation Medicine, Chungnam National University Sejong Hospital, College of Medicine, Chungnam National University, Sejong, Republic of Korea
- *Correspondence: Chang Ho Hwang, MD, PhD, Department of Physical and Rehabilitation Medicine, Chungnam National University Sejong Hospital, College of Medicine, Chungnam National University, 30099, 20, Bodeum 7-ro, Sejong, Republic of Korea (e-mail: )
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Di Gregorio E, Arena F, Gianolio E, Ferrauto G, Aime S. The interaction between iodinated X‐ray contrast agents and macrocyclic
GBCAs
provides a signal enhancement in
T
1
‐weighted MR
images: Insights into the renal excretion pathways of
Gd‐HPDO3A
and iodixanol in healthy mice. Magn Reson Med 2022; 88:357-364. [PMID: 35253921 PMCID: PMC9314041 DOI: 10.1002/mrm.29190] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2021] [Revised: 12/15/2021] [Accepted: 01/18/2022] [Indexed: 12/17/2022]
Abstract
Purpose This work aims to investigate the supramolecular binding interactions that occur between iodinated X‐ray contrast agents (CAs) and macrocyclic gadolinium (Gd)–based MRI contrast agents (GBCAs). This study provides some new insights in the renal excretion pathways of the two types of imaging probes. Methods The water‐proton relaxivities (r1) of clinically approved macrocyclic and linear GBCAs have been measured in the presence of different iodinated X‐ray contrast agents at different magnetic field strengths in buffer and in serum. The in vivo MRI and X‐ray CT of mice injected with either Gd‐HPDO3A or a Gd‐HPDO3A + iodixanol mixture were then acquired to assess the biodistribution of the two probes. Results A significant increase in r1 (up to approximately 200%) was observed for macrocyclic GBCAs when measured in the presence of an excess of iodinated X‐ray CAs (1:100 mol:mol) in serum. The co‐administration of Gd‐HPDO3A and iodixanol in vivo resulted in a marked increase in the signal intensity of the kidney regions in T1‐weighted MR images. Moreover, the co‐presence of the two agents resulted in the extended persistence of the MRI signal enhancement, suggesting that the Gd‐HPDO3A/iodixanol adduct was eliminated more slowly than the typical washing out of Gd‐HPDO3A. Conclusions The reported results show that it is possible to detect the co‐presence of iodinated agents and macrocyclic GBCAs in contrast‐enhanced MR images. The new information may be useful in the design of novel experiments toward improved diagnostic outcomes.
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Affiliation(s)
- Enza Di Gregorio
- Molecular Imaging Center, Department of Molecular Biotechnology and Health Sciences University of Turin Turin Italy
| | - Francesca Arena
- Molecular Imaging Center, Department of Molecular Biotechnology and Health Sciences University of Turin Turin Italy
| | - Eliana Gianolio
- Molecular Imaging Center, Department of Molecular Biotechnology and Health Sciences University of Turin Turin Italy
| | - Giuseppe Ferrauto
- Molecular Imaging Center, Department of Molecular Biotechnology and Health Sciences University of Turin Turin Italy
| | - Silvio Aime
- Istituto di ricovero e cura a carattere scientifico Naples Italy
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Shin H, Cho YM, Lee K, Lee CH, Choi BW, Kim B. Synthesis and characterization of ethosomal contrast agents containing iodine for computed tomography (CT) imaging applications. J Liposome Res 2013; 24:124-9. [PMID: 24188576 DOI: 10.3109/08982104.2013.850592] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
As a first step in the development of novel liver-specific contrast agents using ethosomes for computed tomography (CT) imaging applications, we entrapped iodine within ethosomes, which are phospholipid vesicular carriers containing relatively high alcohol concentrations, synthesized using several types of alcohol, such as methanol, ethanol, and propanol. The iodine containing ethosomes that were prepared using methanol showed the smallest vesicle size (392 nm) and the highest CT density (1107 HU). The incorporation of cholesterol into the ethosomal contrast agents improved the stability of the ethosomes but made the vesicle size large. The ethosomal contrast agents were taken up well by macrophage cells and showed no cellular toxicity. The results demonstrated that ethosomes containing iodine, as prepared in this study, have potential as contrast agents for applications in CT imaging.
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Affiliation(s)
- Hanjin Shin
- Department of Chemical Engineering, Hongik University , Seoul , Korea
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Na B, Choi BW, Kim B. Size and CT density of iodine-containing ethosomal vesicles obtained by membrane extrusion: Potential for use as CT contrast agents. Biotechnol J 2013; 8:1347-53. [DOI: 10.1002/biot.201300110] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2013] [Revised: 05/15/2013] [Accepted: 06/25/2013] [Indexed: 11/05/2022]
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In situ quantification of endothelial cell damage caused by iodinated contrast media using a rat vena cava model. Eur J Radiol 2012; 81:879-84. [DOI: 10.1016/j.ejrad.2011.02.035] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2010] [Revised: 02/07/2011] [Accepted: 02/07/2011] [Indexed: 12/19/2022]
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Rustighi I, Donati I, Ferluga M, Campa C, Pasqua AE, Rossi M, Paoletti S. Borate complexes of x-ray iodinated contrast agents: characterization and sorption studies for their removal from aqueous media. JOURNAL OF HAZARDOUS MATERIALS 2012; 205-206:10-16. [PMID: 22245510 DOI: 10.1016/j.jhazmat.2011.10.084] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2011] [Revised: 10/26/2011] [Accepted: 10/29/2011] [Indexed: 05/31/2023]
Abstract
Iodinated contrast media (ICM) are persistent and ubiquitous water pollutants. Because of their high water solubility and biochemical stability, their phase-separation and recovery from the aquatic environment is very difficult. Here, borate was chosen as a complexing agent of the two diagnostic aids iomeprol and iopamidol in order to provide them with a negative charge and to fix the resulting adducts on Dowex 1X4 ion exchangers. A systematic characterization study of the complex by means of capillary zone electrophoresis and 11B NMR revealed that iomeprol and iopamidol interact with borate anions in aqueous solutions giving a 1:1 single-charged adduct and that the association constant at 25 °C for both contrast agents is highest at pH 10.5. These findings allowed the proper calibration of experimental parameters for further batch adsorption-desorption trials, where the two ICM were shown to be almost completely removed from the water phase and released from the solid sorbents in mild conditions, enabling the recovery of functional resin.
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Affiliation(s)
- Isabella Rustighi
- Department of Life Sciences, University of Trieste, Via Licio Giorgieri 1, 34127 Trieste, Italy.
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Mitsuyama T, Sato S, Ishii A, Kawamata T. Contrast medium-induced seizures and prolonged motor weakness after cerebral angiography: case report. Neurosurgery 2010; 67:E1460-3; discussion E1463. [PMID: 20948393 DOI: 10.1227/neu.0b013e3181f352a1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND AND IMPORTANCE Neurological complications of cerebral angiography are usually embolic events resulting in stroke or seizure of vascular origin. Contrast media rarely induce neurological complications. CLINICAL PRESENTATION Repeated seizures and prolonged motor weakness developed in a 26-year-old woman after cerebral angiography. Neurological deficits remained the next day with slow recovery. Repeat magnetic resonance imaging did not demonstrate any cerebral ischemia even on diffusion-weighted images. The contrast medium was the most likely cause of the neurological deficits. She recovered completely after infusion of the osmotic diuretic. CONCLUSION Although rare, we should take into consideration that contrast media may induce neurological complications after cerebral angiography.
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Affiliation(s)
- Tetsuryu Mitsuyama
- Department of Neurosurgery, Tokyo Women's Medical University, Yachiyo Medical Center, Chiba, Japan
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ROMANO L, GRAZIOLI L, BONOMO L, XU JR, CHEN KM, DORE R, VANZULLI A, CATALANO C. Enhancement and safety of iomeprol-400 and iodixanol-320 in patients undergoing abdominal multidetector CT. Br J Radiol 2009; 82:204-11. [DOI: 10.1259/bjr/93627766] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
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Vijayalakshmi K, Kunadian B, Wright RA, Hall JA, Stewart MJ, Davies A, Sutton A, de Belder MA. A prospective randomised controlled trial to determine the early and late reactions after the use of iopamidol 340 (Niopam™) and iomeprol 350 (Iomeron®) in cardiac catheterisation. Eur J Radiol 2007; 61:342-50. [PMID: 17101256 DOI: 10.1016/j.ejrad.2006.09.013] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2006] [Revised: 09/08/2006] [Accepted: 09/28/2006] [Indexed: 11/28/2022]
Abstract
UNLABELLED A new generation of intravascular contrast agents, the non-ionic monomers have safety profiles that are superior to those of older ionic compounds. There are, however, significant differences between these agents. AIM The aim of this study was to determine the incidence of early (<24h) and late (>24h to 7 days) reactions to two non-ionic contrast agents currently used during cardiac catheterisation: iopamidol 340 (Niopam Bracco UK Ltd.) and iomeprol 350 (Iomeron Bracco UK Ltd.). METHODS This was a prospective, randomised, double blinded trial. One thousand nine hundred and eighty-five patients undergoing cardiac catheterisation received one of the following contrast agents on a weekly basis: iopamidol 340 (Niopam) and iomeprol 350 (Iomeron). Reactions that were possibly related to the contrast agents were recorded on predefined data collection forms during the first 24h of the procedure (early reaction) and after 24h to 7 days (late reaction) by means of a questionnaire. RESULTS The baseline characteristics were matched in both the groups. There was no significant difference in the incidence of heat sensation experienced between the two groups (p=0.1). Early non-heat reactions occurred in 2.7% of patients receiving iopamidol 340 (Niopam) and 4% of those receiving iomeprol 350 (Iomeron) (p=0.1). Significant electrocardiographic changes were recorded in 1.7% of patients who received iopamidol 340 (Niopam), and 1% of those who received iomeprol 350 (Iomeron) (p=0.2). Bradycardia occurred more frequently in the iopamidol 350 group (0.8%) compared to the iomeprol 350 group (0.1%) p=0.02. Late reactions occurred in 16.2% of those receiving iopamidol 340 (Niopam) and 21.7% of those receiving iomeprol 350 (Iomeron) (p=0.02). A total of 23 (3.7%) patients in the iopamidol group and 39 (6.2%) patients in the iomeprol group reported nausea, p=0.01. CONCLUSIONS The incidence of early adverse reactions was similar with the two non-ionic contrast agents. Although bradycardia was slightly more frequent using iopamidol 340, nausea was reported more commonly 24h after the procedure in patients receiving Iomeron 350 (Iomeron). We conclude that there were only minor clinical differences between these agents; both are safe and well tolerated.
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Affiliation(s)
- Kunadian Vijayalakshmi
- Department of Cardiology, The James Cook University Hospital, Marton Road, Middlesbrough TS4 3BW, United Kingdom.
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Downes MO. In Vitro Study of Various Iodinated Contrast Media. Radiology 2006; 239:918-9; author reply 919-21. [PMID: 16714470 DOI: 10.1148/radiol.2393051410] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Szebeni J. Complement activation-related pseudoallergy: a new class of drug-induced acute immune toxicity. Toxicology 2005; 216:106-21. [PMID: 16140450 DOI: 10.1016/j.tox.2005.07.023] [Citation(s) in RCA: 417] [Impact Index Per Article: 21.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2005] [Revised: 07/18/2005] [Accepted: 07/28/2005] [Indexed: 02/06/2023]
Abstract
A major goal in modern pharmacotechnology is to increase the therapeutic index of drugs by using nanoparticulate vehicle systems in order to ensure slow release or targeted delivery of drugs. With all great benefits, however, these innovative therapies can carry a risk for acute immune toxicity manifested in hypersensitivity reactions (HSRs) that do not involve IgE but arises as a consequence of activation of the complement (C) system. These anaphylactoid reactions can be distinguished within the Type I category of HSRs as "C activation-related pseudoallergy" (CARPA). Drugs and agents causing CARPA include radiocontrast media (RCM), liposomal drugs (Doxil, Ambisome and DaunoXome) and micellar solvents containing amphiphilic lipids (e.g., Cremophor EL, the vehicle of Taxol). These agents activate C through both the classical and the alternative pathways, giving rise to C3a and C5a anaphylatoxins that trigger mast cells and basophils for secretory response that underlies HSRs. Pigs provide a useful model for liposome-induced CARPA as minute amounts of reactogenic lipomes cause C activation with consequent dramatic cardiovascular and laboratory abnormalities that mimic some of the human symptoms. Consistent with the causal role of C activation in liposome-induced HSRs, a recent clinical study demonstrated correlation between the formation of C terminal complex (SC5b-9) in blood and the presence of HSRs in patients treated with liposomal doxorubicin (Doxil). Overall, the CARPA concept may help in the prediction, prevention and treatment of the acute immune toxicity of numerous state-of-the-art drugs.
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Affiliation(s)
- Janos Szebeni
- Department of Vaccine Production and Delivery, Division of Retrovirology, Walter Reed Army Institute of Research and Henry Jackson Foundation for Military Medical Research, Silver Spring, MD, USA.
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Heinrich MC, Kuhlmann MK, Grgic A, Heckmann M, Kramann B, Uder M. Cytotoxic effects of ionic high-osmolar, nonionic monomeric, and nonionic iso-osmolar dimeric iodinated contrast media on renal tubular cells in vitro. Radiology 2005; 235:843-9. [PMID: 15845795 DOI: 10.1148/radiol.2353040726] [Citation(s) in RCA: 135] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
PURPOSE To compare the cytotoxic effects of dimeric and monomeric iodinated contrast media on renal tubular cells in vitro with regard to osmolality. MATERIALS AND METHODS LLC-PK1 cells were incubated with ioxithalamate, ioversol, iomeprol-300, iomeprol-150, iodixanol, iotrolan, and hyperosmolar mannitol solutions for 1-24 hours at concentrations from 18.75 to 150 mg of iodine per milliliter. Cytotoxic effects were assessed with 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay. Data were analyzed with one-way analysis of variance; post hoc tests were performed. RESULTS At equal iodine concentrations, ioxithalamate showed stronger cytotoxic effects than did other contrast media (MTT conversion for ioxithalamate was 4% vs that for ioversol of 32%, that for iomeprol-300 of 34%, that for iodixanol of 40%, and that for iotrolan of 41% of undamaged control cells at 75 mg of iodine per milliliter, n = 61-90, P < .001); there was no significant difference between low-osmolar monomeric and iso-osmolar dimeric contrast media (P > .05). At equal molarity, dimeric contrast media induced significantly stronger cytotoxic effects than did low-osmolar monomeric contrast media (40% for iodixanol and 41% for iotrolan vs 64% for ioversol and 59% for iomeprol-300 at 98.5 mmol/L, n = 61-75, P < .001). At equimolar concentrations, both dimeric contrast media showed stronger cytotoxic effects than did iso-osmolar formulation of iomeprol-150 (51% for iodixanol and 50% for iotrolan vs 77% for iomeprol-150 at 98.5 mmol/L, n = 35-40, P < .001). Mannitol solutions induced weaker cytotoxic effects than did corresponding contrast media compounds (74% for mannitol-520 vs 34% for iomeprol-300 and 41% for mannitol-1860 vs 4% for ioxithalamate, P < .001). CONCLUSION Besides hyperosmolality, direct cytotoxic effects of contrast media molecules contribute to their cytotoxic effects. Results of this study indicate that dimeric contrast media molecules have a greater potential for cytotoxic effects on proximal renal tubular cells in vitro than do monomeric contrast media molecules.
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Affiliation(s)
- Marc C Heinrich
- Department of Diagnostic Radiology, Division of Nephrology and Hypertension, University Hospital of Saarland, Homburg/Saar, Germany
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Szebeni J. Hypersensitivity reactions to radiocontrast media: the role of complement activation. Curr Allergy Asthma Rep 2004; 4:25-30. [PMID: 14680617 DOI: 10.1007/s11882-004-0038-9] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Although intravenous use of radiocontrast media (RCM) for a variety of radiographic procedures is generally safe, clinically significant acute hypersensitivity reactions still occur in a significant percentage of patients. The mechanism of these anaphylactoid, or "pseudoallergic," reactions is complex, involving complement activation, direct degranulation of mast cells and basophils, and modulation of enzymes and proteolytic cascades in plasma. In this review, basic information on different RCMs and their reactogenicity is summarized and updated, and the prevalence, pathomechanism, prediction, prevention, treatment, and economic impact of hypersensitivity reactions are discussed. Particular attention is paid to the in vitro and in vivo evidence supporting complement activation as an underlying cause of RCM reactions.
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Affiliation(s)
- Janos Szebeni
- Department of Membrane Biochemistry, Walter Reed Army Institute of Research, 501 Robert Grant Avenue, Silver Spring, MD 20910, USA.
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Uder M, Humke U, Pahl M, Jansen A, Utz J, Kramann B. Nonionic contrast media iohexol and iomeprol decrease renal arterial tone: comparative studies on human and porcine isolated vascular segments. Invest Radiol 2002; 37:440-7. [PMID: 12138360 DOI: 10.1097/00004424-200208000-00005] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
RATIONALE AND OBJECTIVES The vasoconstriction of the renal arteries is frequently considered as a crucial factor for radiocontrast-induced nephropathy. A direct effect of iodinated radiographic contrast medium (RCM) on vascular smooth muscle is supposed to be one component of the vascular response. We studied the effect of the nonionic RCM iomeprol and iohexol on the tonus of isolated human and porcine renal arteries in vitro. METHODS In an organ bath renal arterial rings, uncontracted or precontracted by 10 micromol/L phenylephrine were incubated with increasing concentrations (15-103 mg iodine/mL) of iohexol, iomeprol, and mannitol solution isoosmolar to the contrast media. In a part of the preparations the endothelium was destroyed. Human vessels were obtained from tumor nephrectomy specimens of 10 patients. RESULTS In human experiments iomeprol and iohexol (P < 0.05) relaxed renal arterial rings whereas mannitol produced concentration-dependent contractions. The relaxation by both contrast media was slightly attenuated upon increasing their concentration. The differences between mannitol solutions and RCM were statistically significant (P < 0.001) at concentrations of 57 mg iodine/mL and higher. Precontracted rings were significantly stronger relaxed by the RCM compared with mannitol (P < 0.001). The contrast medium induced relaxation did not depend on the presence of an intact endothelium (P > 0.05). Experiments with renal arterial segments prepared from swine showed similar results, with stronger relaxations than the human preparations. CONCLUSION Iomeprol and iohexol relaxed isolated renal arterial segments. These observations are in contradiction with the hypothesis that contrast media induce nephropathy by a direct vasoconstrictive effect on vascular smooth muscle. They do not exclude, however, a reduction of renal blood flow by other factors like liberation of hormones.
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Affiliation(s)
- Michael Uder
- Department of Diagnostic Radiology, University Hospital of Saarland, Homburg/Saar, Germany.
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Frigeni V, Samuelli G, Miragoli L, Grotti A, Lorusso V. Effect of iomeprol on rat hippocampal slice synaptic transmission: comparison with other X-ray contrast agents. Invest Radiol 2002; 37:222-31. [PMID: 11923645 DOI: 10.1097/00004424-200204000-00008] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
RATIONALE AND OBJECTIVES All contrast agents should be neurologically safe because although some are not indicated for procedures, such as myelography, just the same they may come in contact with nervous tissue during contrast-enhanced imaging. This is because even when they are intravascularly injected, the presence of undiagnosed blood-brain barrier damage may allow them to penetrate the brain barrier. In the present study, we investigated the neurologic safety of iomeprol by studying in vitro its potential effects on the central nervous system (CNS) synaptic transmission. Other widely used x-ray contrast agents were also assessed for comparative purposes. METHODS CNS synaptic transmission was evaluated in terms of evoked field potentials recorded from the pyramidal region of rat hippocampal slices. The field potentials were evoked by electrical stimulation of the Schaffer collateral pathway. The effects of the contrast agents were evaluated in terms of number and amplitude of population spikes (PS) and as the maximal slope of the excitatory postsynaptic potentials (EPSP). The contrast agents were tested at final concentrations of 3, 10, and 30 mg(iodine)/mL in iso-osmolal condition with respect to artificial cerebrospinal fluid (CSF). RESULTS Iomeprol, like ioversol, principally exerted a mild inhibitory effect on CNS synaptic transmission, an effect that was preceded by a weak, transient excitation. Iopentol exerted a rapid and complete inhibition of synaptic transmission without showing any excitatory effects. Iobitridol, though belonging to the nonionic monomeric class, exerted, surprisingly, an epileptogenic action at the highest concentration, whereas its inhibitory action was slow and mild. Diatrizoate, as expected, exerted an epileptogenic activity even at the lowest concentration, followed by a marked inhibitory action. Ioxaglate, as expected because it is an ionic though dimeric contrast agent, exerted an epileptogenic action at the intermediate concentration, whereas it barely demonstrated an inhibitory effect at all. All the contrast agent effects observed in the study reversed or tended to reverse during washout. CONCLUSIONS Even taking in account the limitation because of the use of an in vitro approach and high contrast agent concentrations, we can conclude that the positive neuro-tolerability of iomeprol is further confirmed by this model as it proved to be devoid of epileptogenic activity and, among the contrast agents exhibiting inhibitory action, it was the contrast agent with the least amount of activity. In addition, contrary to that generally reported in the literature, nonionic, low osmolal contrast agents are not all identical in their neuro-tolerability when assessed in the rat hippocampal slice model.
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Uder M, Utz J, Pahl MB, Schneider G, Kramann B, Trautwein W. Iodinated radiographic contrast media inhibit the capacitative calcium entry into smooth muscle cells of the swine renal artery. Invest Radiol 2001; 36:734-42. [PMID: 11753145 DOI: 10.1097/00004424-200112000-00009] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
RATIONALE AND OBJECTIVES To investigate whether nonionic, iodinated, radiographic contrast media (RCM) could modulate calcium release from or calcium entry into smooth muscle cells of the swine renal artery. METHODS Intracellular calcium concentrations of isolated myocytes loaded with the calcium-sensitive dye fluo-3 were analyzed using a fluorescence imaging system. Calcium signals were compared with isometric contractions of vascular segments in an organ bath. The effects of the triiodinated monomer iomeprol were compared with those of a mannitol solution. RESULTS Stimulation of alpha-receptors by phenylephrine caused a biphasic calcium signal. Transient liberation of calcium from intracellular stores triggered the sustained entry of extracellular calcium (capacitative entry). Iomeprol and mannitol slightly inhibited the initial transient spike to the same extent. The calcium influx was reversibly inhibited by RCM by about 50%. Up to a concentration of 40 mmol/L, the inhibition induced by iomeprol was significantly higher than that induced by mannitol (P < 0.05-0.01). In isolated arterial segments, relaxation of the contraction phase depending on the calcium influx was significantly higher with the RCM than with mannitol (P < 0.01). CONCLUSIONS Vasodilatation by CM is associated with a reduction in the capacitative entry of calcium. The mechanism of this effect is not clear, but it can be ruled out that it is mainly due to the high osmolarity of these compounds.
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Affiliation(s)
- M Uder
- Department of Diagnostic Radiology, University Hospital, Kirrberger Strasse 1, 66 421 Homburg/Saar, Germany.
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