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Jin Z, Bertholf RL, Yi X. Assessment of Iohexol Serum Clearance by LC-MS/MS with Isotopically Labeled Internal Standard. Methods Mol Biol 2024; 2737:319-327. [PMID: 38036833 DOI: 10.1007/978-1-0716-3541-4_29] [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] [Indexed: 12/02/2023]
Abstract
Accurate measurement of the glomerular filtration rate (GFR) is essential for detecting renal insufficiency in living kidney donors. Iohexol is a "near-ideal" exogenous filtration marker for GFR measurement that has attracted increasing interest in clinical practice because it is non-toxic, non-radioactive, readily available, and easy to measure. In this chapter, we describe a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method to measure iohexol in serum and to calculate GFR based on the rate of iohexol clearance. In this procedure, the contrast agent iohexol is administrated to the study subject in an outpatient setting, and three timed blood samples are collected. The serum proteins are precipitated, and the supernatant containing iohexol and the internal standard 2H5-iohexol is diluted prior to LC-MS/MS analysis. The LC-MS/MS method utilizes a Thermo Vanquish UHPLC coupled with TSQ Endura triple quadruple mass spectrometer, with a total run time of 2.5 min. The LC-MS/MS method has demonstrated good analytical performances, and the workflow can be used to reliably measure GFR in apparently healthy individuals without impaired renal function, such as living kidney donors.
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Affiliation(s)
- Zhicheng Jin
- Department of Pathology and Laboratory Medicine, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI, USA
| | - Roger L Bertholf
- Department of Pathology and Genomic Medicine, Houston Methodist Hospital, Houston, TX, USA
- Department of Pathology and Laboratory Medicine, Weill Cornell Medical College, New York, NY, USA
| | - Xin Yi
- Department of Pathology and Genomic Medicine, Houston Methodist Hospital, Houston, TX, USA.
- Department of Pathology and Laboratory Medicine, Weill Cornell Medical College, New York, NY, USA.
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Zhou LY, Liu K, Yin WJ, Xie YL, Wang JL, Zuo SR, Tang ZY, Wu YF, Zuo XC. Arginase2 mediates contrast-induced acute kidney injury via facilitating nitrosative stress in tubular cells. Redox Biol 2023; 67:102929. [PMID: 37856999 PMCID: PMC10587771 DOI: 10.1016/j.redox.2023.102929] [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: 09/26/2023] [Accepted: 10/07/2023] [Indexed: 10/21/2023] Open
Abstract
Contrast-induced acute kidney injury(CI-AKI) is the third cause of AKI. Although tubular injury has been regarded as an important pathophysiology of CI-AKI, the underlying mechanism remains elusive. Here, we found arginase2(ARG2) accumulated in the tubules of CI-AKI mice, and was upregulated in iohexol treated kidney tubular cells and in blood samples of CI-AKI mice and patients, accompanied by increased nitrosative stress and apoptosis. However, all of the above were reversed in ARG2 knockout mice, as evidenced by the ameliorated kidney dysfunction and the tubular injury, and decreased nitrosative stress and apoptosis. Mechanistically, HO-1 upregulation could alleviate iohexol or ARG2 overexpression mediated nitrosative stress. Silencing and overexpressing ARG2 was able to upregulate and downregulate HO-1 expression, respectively, while HO-1 siRNA had no effect on ARG2 expression, indicating that ARG2 might inhibit HO-1 expression at the transcriptional level, which facilitated nitrosative stress during CI-AKI. Additionally, CREB1, a transcription factor, bound to the promoter region of ARG2 and stimulated its transcription. Similar findings were yielded in cisplatin- or vancomycin-induced AKI models. Taken together, ARG2 is a crucial target of CI-AKI, and activating CREB1/ARG2/HO-1 axis can mediate tubular injury by promoting nitrosative stress, highlighting potential therapeutic strategy for treating CI-AKI.
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Affiliation(s)
- Ling-Yun Zhou
- Department of Pharmacy, The Third Xiangya Hospital, Central South University, Changsha, China
| | - Kun Liu
- Department of Pharmacy, The Third Xiangya Hospital, Central South University, Changsha, China
| | - Wen-Jun Yin
- Department of Pharmacy, The Third Xiangya Hospital, Central South University, Changsha, China
| | - Yue-Liang Xie
- Department of Pharmacy, The Third Xiangya Hospital, Central South University, Changsha, China
| | - Jiang-Lin Wang
- Department of Pharmacy, The Third Xiangya Hospital, Central South University, Changsha, China
| | - Shan-Ru Zuo
- Department of Pharmacy, The Third Xiangya Hospital, Central South University, Changsha, China
| | - Zhi-Yao Tang
- Department of Pharmacy, The Third Xiangya Hospital, Central South University, Changsha, China
| | - Yi-Feng Wu
- Department of Pharmacy, The Third Xiangya Hospital, Central South University, Changsha, China
| | - Xiao-Cong Zuo
- Department of Pharmacy, The Third Xiangya Hospital, Central South University, Changsha, China; Center of Clinical Pharmacology, The Third Xiangya Hospital, Central South University, Changsha, China.
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Salvador CL, Flemmen PTK, Tøndel C, Bliksrud YT, Tsui EFF, Brun A, Bjerre A, Mørkrid L. Renal function, sex and age influence purines and pyrimidines in urine and could lead to diagnostic misinterpretation. Mol Genet Metab 2023; 140:107649. [PMID: 37517327 DOI: 10.1016/j.ymgme.2023.107649] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/05/2022] [Revised: 06/28/2023] [Accepted: 07/01/2023] [Indexed: 08/01/2023]
Abstract
Glomerular filtration rate (GFR) is commonly used in clinical practice for the diagnosis and follow-up of chronic kidney disease. Screening for inborn errors of metabolism (IEM) is based on analysis of biomarkers in urine, reported by their ratio to urinary creatinine (crn). Impaired renal function may complicate the interpretation of several biomarkers used for screening of IEM. Our goal was to investigate the influence of kidney function, in terms of measured GFR (mGFR) on purines and pyrimidines in urine, in addition to the relationship to sex, age, pH and ketosis. Children (n = 96) with chronic kidney disease (CKD), in different CKD stages, were included. Urine samples were obtained prior to the injection of iohexol. Serum samples at 7 time-points were used to calculate mGFR based on iohexol plasma clearance. The association with sex, age, ketosis and pH was examined in samples of the laboratory production from 2015 to 2021 (n = 8192). Age was a highly significant covariate for all markers. GFR correlated positively to several purines and pyrimidines; the ratios hypoxanthine/crn, xanthine/crn and urate/crn (p = 2.0 × 10-14, < 3 × 10-15 and 7.2 × 10-4, respectively), and the ratios orotic acid/crn, uracil/crn, and carbamyl-β-alanine/crn (p = 0.03, 1.4 × 10-6 and 0.003, respectively). The values of urate/crn, xanthine/crn, uracil/crn, and carbamyl-β-alanine/crn were higher in females above 16 years of age. Ketosis and pH influenced some markers. In conclusion, decreased renal function interferes with the excretion of urinary purines and pyrimidines, and this could change decision limits substantially, e.g. result in false negative results in Lesch-Nyhan syndrome. SYNOPSIS: GFR influences purines and pyrimidines in urine. Clinical Trial Registration: ClinicalTrials.gov, Identifier NCT01092260, https://clinicaltrials.gov/ct2/show/NCT01092260?term=tondel&rank=2.
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Affiliation(s)
| | | | - Camilla Tøndel
- Department of Pediatrics, Haukeland University Hospital, Bergen, Norway; Department of Clinical Science, University of Bergen, Bergen, Norway
| | | | | | - Atle Brun
- Department of Clinical Science, University of Bergen, Bergen, Norway; Department of Medical Biochemistry and Pharmacology, Haukeland University Hospital, Bergen, Norway
| | - Anna Bjerre
- Department of Pediatrics, Oslo University Hospital, Oslo, Norway; Institute of Clinical Medicine, University of Oslo, Oslo, Norway
| | - Lars Mørkrid
- Department of Medical Biochemistry, Oslo University Hospital, Oslo, Norway; Institute of Clinical Medicine, University of Oslo, Oslo, Norway
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Yang D, Yang X, Chen S, Lv M, Tan J, Yang D. Ox-LDL aggravates contrast-induced injury of renal tubular epithelial cells. J Biochem Mol Toxicol 2023; 37:e23379. [PMID: 37186061 DOI: 10.1002/jbt.23379] [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] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Revised: 02/04/2023] [Accepted: 04/14/2023] [Indexed: 05/17/2023]
Abstract
Hypercholesterolemia can aggravate contrast-induced acute kidney injury, and the exacerbation of renal tubular epithelial cell (RTEC) injury is a major cause. However, the exact mechanisms remain obscure. Mitophagy, a type of autophagy, selectively eliminates damaged mitochondria and reduces mitochondrial oxidative stress, which is strongly implicated in cell homeostasis and acute kidney injury. Oxidized low-density lipoprotein (Ox-LDL) is accumulated in hypercholesterolemia and has a cytotoxic effect. This study aimed to determine whether and how ox-LDL exacerbates contrast-induced injury in RTECs and to further explore whether PINK1/Parkin-dependent mitophagy is involved in this process. Iohexol and ox-LDL were used alone or in combination to treat HK-2 cells. Rapamycin pretreatment was utilized to enhance mitophagy. Cell viability, apoptosis, mitochondrial membrane potential (MMP) and mitochondrial reactive oxygen species (mtROS) were detected by cell counting kit-8, TUNEL staining, JC-1 kit and MitoSOX fluorescence, respectively. The expression of mitophagy-related proteins (including PINK1, Parkin, and so on) and cleaved caspase-3 was confirmed by western blot. Colocalization of MitoTracker-labeled mitochondria and LysoTracker-labeled lysosomes was observed by fluorescence microscopy to evaluate mitophagy. The results of our study showed that ox-LDL aggravated MMP decline, mtROS release and apoptosis in iohexol-treated HK-2 cells, accompanied by a further increased autophagy level. Enhancement of PINK1/Parkin-dependent mitophagy by rapamycin alleviated apoptosis and mitochondrial injury in HK-2 cells in response to iohexol under ox-LDL condition. Therefore, our findings indicate that ox-LDL aggravates contrast-induced injury of RTECs by increasing mitochondrial damage and mitochondrial oxidative stress, which may be associated with the relative insufficiency of PINK1/Parkin-dependent mitophagy.
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Affiliation(s)
- Dingwei Yang
- Department of Nephrology, Tianjin Hospital of Tianjin University, Tianjin, China
| | - Xueyan Yang
- Department of Nephrology, Renmin Hospital of Wuhan University, Wuhan, Hubei, China
| | - Sha Chen
- Department of Nephrology, Tianjin Hospital of Tianjin University, Tianjin, China
| | - Meiling Lv
- Clinical College of Orthopedics, Tianjin Medical University, Tianjin, China
| | - Jin Tan
- Department of Geriatrics, Tianjin Medical University General Hospital, Tianjin Geriatrics Institute, Tianjin, China
| | - Dingping Yang
- Department of Nephrology, Renmin Hospital of Wuhan University, Wuhan, Hubei, China
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Woillard JB, Salmon Gandonnière C, Destere A, Ehrmann S, Merdji H, Mathonnet A, Marquet P, Barin-Le Guellec C. A Machine Learning Approach to Estimate the Glomerular Filtration Rate in Intensive Care Unit Patients Based on Plasma Iohexol Concentrations and Covariates. Clin Pharmacokinet 2020; 60:223-233. [PMID: 32794122 DOI: 10.1007/s40262-020-00927-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
OBJECTIVE This work aims to evaluate whether a machine learning approach is appropriate to estimate the glomerular filtration rate in intensive care unit patients based on sparse iohexol pharmacokinetic data and a limited number of predictors. METHODS Eighty-six unstable patients received 3250 mg of iohexol intravenously and had nine blood samples collected 5, 30, 60, 180, 360, 540, 720, 1080, and 1440 min thereafter. Data splitting was performed to obtain a training (75%) and a test set (25%). To estimate the glomerular filtration rate, 37 candidate potential predictors were considered and the best machine learning approach among multivariate-adaptive regression spline and extreme gradient boosting (Xgboost) was selected based on the root-mean-square error. The approach associated with the best results in a ten-fold cross-validation experiment was then used to select the best limited combination of predictors in the training set, which was finally evaluated in the test set. RESULTS The Xgboost approach yielded the best performance in the training set. The best combination of covariates comprised iohexol concentrations at times 180 and 720 min; the relative deviation from these theoretical times; the difference between these two concentrations; the Simplified Acute Physiology Score II; serum creatinine; and the fluid balance. It resulted in a root-mean-square error of 6.2 mL/min and an r2 of 0.866 in the test set. Interestingly, the eight patients in the test set with a glomerular filtration rate < 30 mL/min were all predicted accordingly. CONCLUSIONS Xgboost provided accurate glomerular filtration rate estimation in intensive care unit patients based on two timed blood concentrations after iohexol intravenous administration and three additional predictors.
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Affiliation(s)
- Jean-Baptiste Woillard
- Faculté de Médecine de Limoges, University of Limoges, IPPRITT, 2 rue du docteur Marcland, 87025, Limoges cedex, France.
- INSERM, IPPRITT, U1248, 87000, Limoges, France.
- Department of Pharmacology and Toxicology, CHU Limoges, 87000, Limoges, France.
| | - Charlotte Salmon Gandonnière
- Médecine Intensive Réanimation, INSERM CIC 1415, CRICS-TriggerSep Research Network, CHRU de Tours, 37044, Tours, France
| | - Alexandre Destere
- Faculté de Médecine de Limoges, University of Limoges, IPPRITT, 2 rue du docteur Marcland, 87025, Limoges cedex, France
- INSERM, IPPRITT, U1248, 87000, Limoges, France
- Department of Pharmacology and Toxicology, CHU Limoges, 87000, Limoges, France
| | - Stephan Ehrmann
- Médecine Intensive Réanimation, INSERM CIC 1415, CRICS-TriggerSep Research Network, CHRU de Tours, 37044, Tours, France
- Centre D'étude Des Pathologies Respiratoires INSERM U1100, Faculté de médecine, Université de Tours, Tours, France
| | - Hamid Merdji
- Faculté de Médecine, Hôpitaux universitaires de Strasbourg, Nouvel Hôpital Civil, Service de réanimation, Université de Strasbourg (UNISTRA), Strasbourg, France
- UMR 1260, Regenerative Nano Medecine, INSERM, Fédération de Médecine Translationnelle de Strasbourg (FMTS), Université de Strasbourg, Strasbourg, France
| | - Armelle Mathonnet
- Médecin Intensive Réanimation, Centre Hospitalier Régional D'Orléans, Orléans, France
| | - Pierre Marquet
- Faculté de Médecine de Limoges, University of Limoges, IPPRITT, 2 rue du docteur Marcland, 87025, Limoges cedex, France
- INSERM, IPPRITT, U1248, 87000, Limoges, France
- Department of Pharmacology and Toxicology, CHU Limoges, 87000, Limoges, France
| | - Chantal Barin-Le Guellec
- INSERM, IPPRITT, U1248, 87000, Limoges, France
- Laboratoire de Biochimie Et de Biologie Moléculaire, CHU de Tours, 37044, Tours, France
- Université de Tours, 37044, Tours, France
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Snead EC, Milo JE, McCrea CA, Montgomery JE, Feng CX, Wesolowski MJ, Wanasundara SN, Wesolowski CA. Tikhonov gamma variate adaptive regularization applied to technetium Tc 99m diethylenetriamine pentaacetic acid plasma clearance, compared with three other methods, for measuring glomerular filtration rate in cats. Am J Vet Res 2019; 80:416-424. [PMID: 30919678 DOI: 10.2460/ajvr.80.4.416] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To evaluate agreement of 4 methods (Tikhonov gamma variate adaptive regularization of plasma concentration-time curve fitting applied to technetium Tc 99m diethylenetriamine pentaacetic acid [99mTc-DTPA] plasma clearance [Tk-GV], plasma clearance of exogenous creatinine [CrCL], Gates gamma camera-based measurement method with 99mTc-DTPA renal clearance and dynamic scintigraphy [GTS], and iohexol renal clearance assessed with dynamic CT with Patlak plotting [CT-Pp]) for measuring glomerular filtration rates (GFR) in healthy cats. ANIMALS 7 healthy, laboratory-raised cats. PROCEDURES Each method for measuring GFR was performed twice in 7 cats at 24-day intervals. The Wilcoxon signed-rank sum test was used to compare the results obtained from the 14 studies for each method. Results from the 4 methods were assessed for agreement and correlation. RESULTS The median GFR values were 2.75, 2.83, 3.14, and 4.26 mL/min/kg, for Tk-GV, CT-Pp, plasma CrCL, and GTS, respectively. Analysis with Wilcoxon signed-rank sum tests identified significant pairwise differences between results obtained with the Tk-GV versus the plasma CrCL method, the Tk-GV versus the GTS method, and the plasma CrCL versus the GTS method. The least variable method was Tk-GV, with an SD of 1.27 (mL/min/kg). CONCLUSIONS AND CLINICAL RELEVANCE Findings indicated that Tk-GV yielded GFR measurements comparable with those obtained with CT-Pp, plasma CrCL, and GTS; however, the Tk-GV method yielded the tightest range of results among the methods evaluated.
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Lv XD, Cui YH, Xue WJ, Yang SQ, Li JY, Liu ZQ. Comparison of inert and non-inert cathode in cathode/Fe 3+/Peroxymonosulfate processes on iohexol degradation. Chemosphere 2019; 223:494-503. [PMID: 30784756 DOI: 10.1016/j.chemosphere.2019.02.079] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2018] [Revised: 01/13/2019] [Accepted: 02/13/2019] [Indexed: 06/09/2023]
Abstract
To investigate the effect of cathode materials on organics degradation in a cathode/Fe3+/PMS process, different cathode materials (platinum, copper and iron) were selected and their performances were compared with iohexol as target organics. The optimal conditions were found to be different for different cathode/Fe3+/PMS processes. With a relatively high cathodic current input (2.0 mA/cm2), similar results were found for all the three cathode/Fe3+/PMS processes. With a small cathodic current input (not higher than 1.0 mA/cm2), the iohexol removal followed the order of Fe-cathode/Fe3+/PMS > Cu-cathode/Fe3+/PMS > Pt-cathode/Fe3+/PMS, due to the corrosion of Cu-cathode and Fe-cathode and the more serious corrosion of Fe-cathode than Cu-cathode. The corrosion of non-inert cathode materials (Cu-cathode and Fe-cathode) meant that these cathodes not only transmitted electrons but also participated in aqueous reactions, which complicated the mechanisms of cathode/Fe3+/PMS processes. The radical identification experiments indicated that SO4- was more important than OH for iohexol degradation in Cu-cathode/Fe3+/PMS process, while OH played a major role in Pt-cathode/Fe3+/PMS and Fe-cathode/Fe3+/PMS processes. The different reaction mechanisms resulted in different iohexol transformation pathways in cathode/Fe3+/PMS processes with different cathode materials.
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Affiliation(s)
- Xu-Dong Lv
- School of Environmental Science and Engineering, Huazhong University of Science and Technology, No. 1037 Luoyu Road, Wuhan 430074, PR China; School of Environmental Science and Engineering, Sun Yat-Sen University, No. 135, Xingang Xi Road, Guangzhou 510275, PR China
| | - Yu-Hong Cui
- School of Environmental Science and Engineering, Huazhong University of Science and Technology, No. 1037 Luoyu Road, Wuhan 430074, PR China.
| | - Wei-Jun Xue
- School of Environmental Science and Engineering, Huazhong University of Science and Technology, No. 1037 Luoyu Road, Wuhan 430074, PR China
| | - Sui-Qin Yang
- School of Environmental Science and Engineering, Huazhong University of Science and Technology, No. 1037 Luoyu Road, Wuhan 430074, PR China
| | - Jia-Ying Li
- School of Environmental Science and Engineering, Huazhong University of Science and Technology, No. 1037 Luoyu Road, Wuhan 430074, PR China
| | - Zheng-Qian Liu
- School of Environmental Science and Engineering, Huazhong University of Science and Technology, No. 1037 Luoyu Road, Wuhan 430074, PR China.
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Staples A, Wong C, Schwartz GJ. Iohexol-measured glomerular filtration rate in children and adolescents with chronic kidney disease: a pilot study comparing venous and finger stick methods. Pediatr Nephrol 2019; 34:459-464. [PMID: 30315406 PMCID: PMC6581035 DOI: 10.1007/s00467-018-4110-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/26/2018] [Revised: 09/28/2018] [Accepted: 10/02/2018] [Indexed: 11/27/2022]
Abstract
BACKGROUND Measurement of glomerular filtration rate by iohexol disappearance (iGFR) has become a gold standard in the pediatric chronic kidney disease (CKD) population. The need for serial phlebotomy can be difficult and minimizing venipunctures would be beneficial. Furthermore, finger stick collection for dried blood spot (DBS) may be more tolerable in the pediatric population, and equivalence between these two methods may further simplify the process. METHODS This was a cross-sectional study in children and adolescents 1 to 21 years with stages I-IV CKD. Iohexol was infused and blood drawn 10, 30, 120, and 300 min later. Blood spots on filter paper were collected by finger stick after each of the latter two blood draws. The rate of iohexol plasma disappearance was used to calculate GFR. Pearson's correlation coefficient and bias, Students t test, and Bland-Altman graphical representations were used to compare methods. RESULTS Forty-one patients were recruited. The mean creatinine was 1.13 mg/dL (SD 0.45), the mean 4-point iGFR was 73.2 ml/min/1.73m2 (SD 27.5) and the mean 2-point iGFR was 75.6 ml/min/1.73m2 (SD 27.3). Correlation between 2-point and 4-point venous GFR was r = 0.97; p < 0.001. The correlation between the DBS and the 2-point venous GFR was r = 0.95; p < 0.001, with no significant bias. Ninety-four percent of the 2-point GFR's were within 10% of the 4-point GFR's and 80% of DBS-GFRs were within 10% of the 2-point GFR's. CONCLUSIONS The 2-point iGFR was highly correlated and agreed well with the 4-point iGFR. The same was true for the DBS method and the 2-point venous method. DBS sampling by finger stick sampling at 2 time points after iohexol infusion gave an acceptably accurate measurement of GFR.
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Affiliation(s)
- Amy Staples
- University of New Mexico, MSC10-5590, Albuquerque, NM, 87131, USA.
| | - Craig Wong
- University of New Mexico, MSC10-5590, Albuquerque, NM, 87131, USA
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Zhang Y, Lyu T, Zhang L, Button M, Arias CA, Weber KP, Shi J, Chen Z, Brix H, Carvalho PN. Microbial community metabolic profiles in saturated constructed wetlands treating iohexol and ibuprofen. Sci Total Environ 2019; 651:1926-1934. [PMID: 30317179 DOI: 10.1016/j.scitotenv.2018.10.103] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/23/2018] [Revised: 10/08/2018] [Accepted: 10/08/2018] [Indexed: 06/08/2023]
Abstract
The aim of the present study was to elucidate the microbial community metabolic profiles in saturated constructed wetland (CW) mesocosms planted with five different wetland plant species fed with water individually spiked with 100 μg L-1 ibuprofen or iohexol. Community-level physiological profiling (CLPP) using Biolog Ecoplates was performed and coupled with the assessment of water quality parameters (water temperature, pH, DO and TOC, TN, NH4-N, PO4-P removal efficiency). The microbial community metabolic profiles (microbial activity, richness, and carbon source utilization), as well as the water quality parameters revealed similar trends among the control mesocosms and the mesocosms fed with water spiked with iohexol and ibuprofen. Significant differences were observed between the planted and unplanted mesocosms and between seasons (summer and winter) within each of the feeding lines (control, iohexol or ibuprofen). The microbial community metabolic profiles in the saturated CW were shaped by plant presence and plant species, while no negative impact of iohexol and ibuprofen presence was noticed at the 100 μg L-1. In addition, the microbial activity and richness were generally higher in planted mesocosms than in the unplanted systems in the summer. For the first time, a positive correlation between iohexol removal and the microbial community metabolic profiles (activity, richness and amines and amides utilization in summer, and carbohydrates utilization in winter) in the saturated mesocosms was observed. Putrescine utilization in the summer and d-cellobiose, d,l-alpha-glycerol phosphate in winter were linked with the metabolic processing of iohexol, while glycogen in summer and l-phenylalanine, Glycyl-l-glutamic acid in winter were linked with ibuprofen removal efficiency in the saturated CW.
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Affiliation(s)
- Yang Zhang
- Department of Bioscience, Aarhus University, Aarhus 8000C, Denmark; School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, PR China; College of Life Science, South China Normal University, Guangzhou 510631, PR China
| | - Tao Lyu
- Department of Bioscience, Aarhus University, Aarhus 8000C, Denmark; School of Animal, Rural and Environmental Science, Nottingham Trent University, Nottinghamshire NG25 0QF, UK
| | - Liang Zhang
- Department of Bioscience, Aarhus University, Aarhus 8000C, Denmark
| | - Mark Button
- Department of Chemistry and Chemical Engineering, Royal Military College of Canada, Kingston, ON K7K 7B4, Canada; Fipke Laboratory for Trace Element Research, Earth, Environmental and Geographic Sciences, University of British Columbia Okanagan, Kelowna V1V 1V7, BC, Canada
| | - Carlos A Arias
- Department of Bioscience, Aarhus University, Aarhus 8000C, Denmark; WATEC - Centre for Water Technology, Aarhus University, Aarhus 8000C, Denmark
| | - Kela P Weber
- Department of Chemistry and Chemical Engineering, Royal Military College of Canada, Kingston, ON K7K 7B4, Canada
| | - Jianghong Shi
- School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, PR China
| | - Zhanghe Chen
- College of Life Science, South China Normal University, Guangzhou 510631, PR China
| | - Hans Brix
- Department of Bioscience, Aarhus University, Aarhus 8000C, Denmark; WATEC - Centre for Water Technology, Aarhus University, Aarhus 8000C, Denmark
| | - Pedro N Carvalho
- Department of Bioscience, Aarhus University, Aarhus 8000C, Denmark; WATEC - Centre for Water Technology, Aarhus University, Aarhus 8000C, Denmark; Department of Environmental Science, Aarhus University, Frederiksborgsvej 399, 4000 Roskilde, Denmark.
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Ng DK, Schwartz GJ, Schneider MF, Furth SL, Warady BA. Combination of pediatric and adult formulas yield valid glomerular filtration rate estimates in young adults with a history of pediatric chronic kidney disease. Kidney Int 2018; 94:170-177. [PMID: 29735307 PMCID: PMC6015546 DOI: 10.1016/j.kint.2018.01.034] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2017] [Revised: 01/19/2018] [Accepted: 01/25/2018] [Indexed: 02/06/2023]
Abstract
As patients with chronic kidney disease (CKD) transition from pediatric nephrology care to adult care, their kidney function is clinically assessed by estimated glomerular filtration rate (eGFR) using both pediatric and adult equations, which may not be congruent. Here we evaluated commonly used eGFR equations and directly measured iohexol GFR (iGFR) among participants between ages 18 and 26 with a diagnosis of pediatric CKD in the Chronic Kidney Disease in Children (CKiD) cohort. The bedside serum creatinine (SCr)-only equation (CKiDSCr), the SCr-only CKD-EPI (CKD-EPISCr), the cystatin C (Cys)-only CKD-EPI (CKD-EPICys) and the combined SCr and Cys CKD-EPI (CKD-EPISCr-Cys) were compared with a) 279 measured iGFRs obtained from 187 participants and b) 548 eGFRs from the SCr and Cys-based CKiD equation (CKiDSCr-Cys) obtained from 219 participants. Among emerging adults with a median iGFR of 49 ml/min/1.73m2, the CKiDSCr-Cys equation had low bias (+1.5 ml/min/1.73m2) and high correlation (0.94), while CKiDSCr underestimated iGFR and CKiDSCr-Cys (-5.6 and -7.4 ml/min/1.73m2, respectively) and CKD-EPISCr had an overestimation bias (+8.2 and +6.1 ml/min/1.73m2, respectively). However, the CKD-EPICys and CKD-EPISCr-Cys exhibited strong agreement with both iGFR and CKiDSCr-Cys. GFR may also be validly estimated in this population by taking the simple average of CKiDSCr and CKD-EPISCr (average bias +1.3 compared to iGFR and -0.6 compared to CKiDSCr-Cys). Clinicians should be aware that individually the pediatric and adult SCr-based estimates of GFR had large discrepancies among emerging adults with pediatric CKD. Thus, when cystatin C is not available, we recommend the average of pediatric and adult SCr-based eGFR as a valid tool for clinical use.
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Affiliation(s)
- Derek K Ng
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA.
| | - George J Schwartz
- Department of Pediatrics, Division of Pediatric Nephrology, University of Rochester Medical Center, Rochester, New York, USA
| | - Michael F Schneider
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA
| | - Susan L Furth
- Department of Pediatrics, Division of Nephrology, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA; Center for Clinical Epidemiology and Biostatistics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Bradley A Warady
- Division of Pediatric Nephrology, Children's Mercy Kansas City, Kansas City, Missouri, USA
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11
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Bukabau JB, Sumaili EK, Cavalier E, Pottel H, Kifakiou B, Nkodila A, Makulo JRR, Mokoli VM, Zinga CV, Longo AL, Engole YM, Nlandu YM, Lepira FB, Nseka NM, Krzesinski JM, Delanaye P. Performance of glomerular filtration rate estimation equations in Congolese healthy adults: The inopportunity of the ethnic correction. PLoS One 2018; 13:e0193384. [PMID: 29499039 PMCID: PMC5834186 DOI: 10.1371/journal.pone.0193384] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2017] [Accepted: 02/11/2018] [Indexed: 11/26/2022] Open
Abstract
Context and objective In the estimation of glomerular filtration rate (GFR), ethnicity is an important determinant. However, all existing equations have been built solely from Caucasian and Afro-American populations and they are potentially inaccurate for estimating GFR in African populations. We therefore evaluated the performance of different estimated GFR (eGFR) equations in predicting measured GFR (mGFR). Methods In a cross-sectional study, 93 healthy adults were randomly selected in the general population of Kinshasa, Democratic Republic of the Congo, between June 2015 and April 2016. We compared mGFR by plasma clearance of iohexol with eGFR obtained with the Modified Diet in Renal Disease (MDRD) equation with and without ethnic factor, the Chronic Kidney Disease Epidemiology (CKD-EPI) serum creatinine (SCr)-based equation, with and without ethnic factor, the cystatin C-based CKD-EPI equation (CKD-EPI SCys) and with the combined equation (CKD-EPI SCrCys) with and without ethnic factor. The performance of the equations was studied by calculating bias, precision and accuracy within 30% (P30) of mGFR. Results There were 48 women and 45 men. Their mean age was 45.0±15.7 years and the average body surface area was 1.68±0.16m2. Mean mGFR was 92.0±17.2 mL/min/1.73m2 (range of 57 to 141 mL/min/1.73m2). Mean eGFRs with the different equations were 105.5±30.1 and 87.2±24.8 mL/min/1.73m2 for MDRD with and without ethnic factor, respectively; 108.8±24.1 and 94.3x20.9 mL/min/1.73m2 for CKD-EPI SCr with and without ethnic factor, respectively, 93.5±18.6 mL/min/1.73m2 for CKD-EPI SCys; 93.5±18.0 and 101±19.6 mL/min/ 1.73m2 for CKD-EPI SCrCys with and without ethnic factor, respectively. All equations slightly overestimated mGFR except MDRD without ethnic factor which underestimated by -3.8±23.0 mL/min /1.73m2. Both CKD-EPI SCr and MDRD with ethnic factors highly overestimated mGFR with a bias of 17.9±19.2 and 14.5±27.1 mL/min/1.73m2, respectively. There was a trend for better P30 for MDRD and CKD-EPI SCr without than with the ethnic factor [86.0% versus 79.6% for MDRD (p = 0.21) and 81.7% versus 73.1% for the CKD-EPI SCr equations (p = 0.057)]. CKD-EPI SCrCys and CKD-EPI SCys were more effective than creatinine-based equations. Conclusion In the Congolese healthy population, MDRD and CKD-EPI equations without ethnic factors had better performance than the same equations with ethnic factor. The equations using Cys C (alone or combined with SCr) performed better than the creatinine-based equations.
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Affiliation(s)
- Justine B. Bukabau
- Renal Unit, Department of Internal medicine, Kinshasa University Hospital, University of Kinshasa, Kinshasa, Democratic Republic of the Congo
- * E-mail:
| | - Ernest K. Sumaili
- Renal Unit, Department of Internal medicine, Kinshasa University Hospital, University of Kinshasa, Kinshasa, Democratic Republic of the Congo
| | - Etienne Cavalier
- Division of Clinical Chemistry, CHU Sart Tilman (ULg CHU), University of Liège, Liège, Belgium
| | - Hans Pottel
- Division of Public Health and Primary Care, KU Leuven Campus Kulak Kortrijk, Kortrijk, Belgium
| | - Bejos Kifakiou
- Renal Unit, Department of Internal medicine, Kinshasa University Hospital, University of Kinshasa, Kinshasa, Democratic Republic of the Congo
| | - Aliocha Nkodila
- Renal Unit, Department of Internal medicine, Kinshasa University Hospital, University of Kinshasa, Kinshasa, Democratic Republic of the Congo
| | - Jean Robert R. Makulo
- Renal Unit, Department of Internal medicine, Kinshasa University Hospital, University of Kinshasa, Kinshasa, Democratic Republic of the Congo
| | - Vieux M. Mokoli
- Renal Unit, Department of Internal medicine, Kinshasa University Hospital, University of Kinshasa, Kinshasa, Democratic Republic of the Congo
| | - Chantal V. Zinga
- Renal Unit, Department of Internal medicine, Kinshasa University Hospital, University of Kinshasa, Kinshasa, Democratic Republic of the Congo
| | - Augustin L. Longo
- Renal Unit, Department of Internal medicine, Kinshasa University Hospital, University of Kinshasa, Kinshasa, Democratic Republic of the Congo
| | - Yannick M. Engole
- Renal Unit, Department of Internal medicine, Kinshasa University Hospital, University of Kinshasa, Kinshasa, Democratic Republic of the Congo
| | - Yannick M. Nlandu
- Renal Unit, Department of Internal medicine, Kinshasa University Hospital, University of Kinshasa, Kinshasa, Democratic Republic of the Congo
| | - François B. Lepira
- Renal Unit, Department of Internal medicine, Kinshasa University Hospital, University of Kinshasa, Kinshasa, Democratic Republic of the Congo
| | - Nazaire M. Nseka
- Renal Unit, Department of Internal medicine, Kinshasa University Hospital, University of Kinshasa, Kinshasa, Democratic Republic of the Congo
| | - Jean Marie Krzesinski
- Division of Nephrology-Dialysis-Transplantation, CHU Sart Tilman (ULg CHU), University of Liège, Liège, Belgium
| | - Pierre Delanaye
- Division of Nephrology-Dialysis-Transplantation, CHU Sart Tilman (ULg CHU), University of Liège, Liège, Belgium
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Selistre LDS, Cochat P, Rech DL, Parant F, de Souza VC, Dubourg L. Association between glomerular filtration rate (measured by high-performance liquid chromatography with iohexol) and plasma oxalate. J Bras Nefrol 2018; 40:73-76. [PMID: 29738022 PMCID: PMC6533971 DOI: 10.1590/1678-4685-jbn-3743] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2017] [Accepted: 08/31/2017] [Indexed: 11/22/2022] Open
Abstract
INTRODUCTION Secondary hyperoxalemia is a multifactorial disease that affects several organs and tissues in patients with native or transplanted kidneys. Plasma oxalate may increase during renal failure because it is cleared from the body by the kidneys. However, there is scarce evidence about the association between glomerular filtration rate and plasma oxalate, especially in the early stages of chronic kidney disease (CKD). METHODS A case series focuses on the description of variations in clinical presentation. A pilot study was conducted using a cross-sectional analysis with 72 subjects. The glomerular filtration rate (GFR) and plasma oxalate levels were measured for all patients. Results: Median (IQR) GFR was 70.50 [39.0; 91.0] mL/min/1.73 m2. Plasma oxalate was < 5.0 µmol/L in all patients with a GFR > 30 mL/min/1.73m2. Among the 14 patients with severe CKD (GFR < 30 mL/min/1.73 m2) only 4 patients showed a slightly increased plasma oxalate level (between 6 and 12 µmol/L). CONCLUSION In non-primary hyperoxaluria, plasma oxalate concentration increases when GFR < 30mL/min/1.73 m2 and, in our opinion, values greater than 5 µmol/L with a GFR > 30 mL/min/1.73 m2 are suggestive of primary hyperoxaluria. Further studies are necessary to confirm plasma oxalate increase in patients with low GFR levels (< 30mL/min/1.73 m2).
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Affiliation(s)
| | - Pierre Cochat
- Université Claude-Bernard Lyon, Centre de Référence des Maladies
Rénales Rares Nephrogones, Service de Néphrologie et Rhumatologie Pédiatriques,
Lyon, France
| | | | - François Parant
- Hospices Civils de Lyon, GHS - Centre de Biologie Sud, UM
Pharmacologie - Toxicologie, F-69495, Pierre Bénite, France
| | | | - Laurence Dubourg
- Université Claude-Bernard, Groupement Hospitalier Edouard Herriot,
Hospices Civils de Lyon, UMR 5305, Rhone-Alpes, Lyon, France
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Cruz-Zavala AS, Pat-Espadas AM, Rangel-Mendez JR, Chazaro-Ruiz LF, Ascacio-Valdes JA, Aguilar CN, Cervantes FJ. Immobilization of metal-humic acid complexes in anaerobic granular sludge for their application as solid-phase redox mediators in the biotransformation of iopromide in UASB reactors. Bioresour Technol 2016; 207:39-45. [PMID: 26868154] [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] [Subscribe] [Scholar Register] [Received: 12/16/2015] [Revised: 01/21/2016] [Accepted: 01/30/2016] [Indexed: 06/05/2023]
Abstract
Metal-humic acid complexes were synthesized and immobilized by a granulation process in anaerobic sludge for their application as solid-phase redox mediators (RM) in the biotransformation of iopromide. Characterization of Ca- and Fe-humic acid complexes revealed electron accepting capacities of 0.472 and 0.556milli-equivalentsg(-1), respectively. Once immobilized, metal-humic acid complexes significantly increased the biotransformation of iopromide in upflow anaerobic sludge blanket (UASB) reactors. Control UASB reactor (without humic material) achieved 31.6% of iopromide removal, while 80% was removed in UASB reactors supplied with each metal-humic acid complex. Further analyses indicated multiple transformation reactions taking place in iopromide including deiodination, N-dealkylation, decarboxylation and deacetylation. This is the first successful application of immobilized RM, which does not require a supporting material to maintain the solid-phase RM in long term operation of bioreactors. The proposed redox catalyst could be suitable for enhancing the redox conversion of different recalcitrant pollutants present in industrial effluents.
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Affiliation(s)
- Aracely S Cruz-Zavala
- División de Ciencias Ambientales, Instituto Potosino de Investigación Científica y Tecnológica (IPICYT), Camino a la Presa San José 2055, Col. Lomas 4ª. Sección, C. P. 78216 San Luis Potosí, SLP, Mexico
| | - Aurora M Pat-Espadas
- División de Ciencias Ambientales, Instituto Potosino de Investigación Científica y Tecnológica (IPICYT), Camino a la Presa San José 2055, Col. Lomas 4ª. Sección, C. P. 78216 San Luis Potosí, SLP, Mexico
| | - J Rene Rangel-Mendez
- División de Ciencias Ambientales, Instituto Potosino de Investigación Científica y Tecnológica (IPICYT), Camino a la Presa San José 2055, Col. Lomas 4ª. Sección, C. P. 78216 San Luis Potosí, SLP, Mexico
| | - Luis F Chazaro-Ruiz
- División de Ciencias Ambientales, Instituto Potosino de Investigación Científica y Tecnológica (IPICYT), Camino a la Presa San José 2055, Col. Lomas 4ª. Sección, C. P. 78216 San Luis Potosí, SLP, Mexico
| | - Juan A Ascacio-Valdes
- Facultad de Ciencias Químicas, Departamento de Investigación en Alimentos (DIA-UAdeC), Universidad Autónoma de Coahuila, Saltillo 25280, Coahuila, Mexico
| | - Cristobal N Aguilar
- Facultad de Ciencias Químicas, Departamento de Investigación en Alimentos (DIA-UAdeC), Universidad Autónoma de Coahuila, Saltillo 25280, Coahuila, Mexico
| | - Francisco J Cervantes
- División de Ciencias Ambientales, Instituto Potosino de Investigación Científica y Tecnológica (IPICYT), Camino a la Presa San José 2055, Col. Lomas 4ª. Sección, C. P. 78216 San Luis Potosí, SLP, Mexico.
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Zhang Y, Lv T, Carvalho PN, Arias CA, Chen Z, Brix H. Removal of the pharmaceuticals ibuprofen and iohexol by four wetland plant species in hydroponic culture: plant uptake and microbial degradation. Environ Sci Pollut Res Int 2016; 23:2890-2898. [PMID: 26490885 DOI: 10.1007/s11356-015-5552-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/04/2015] [Accepted: 10/05/2015] [Indexed: 05/29/2023]
Abstract
We aimed at assessing the effects of four wetland plant species commonly used in constructed wetland systems: Typha, Phragmites, Iris and Juncus for removing ibuprofen (IBU) and iohexol (IOH) from spiked culture solution and exploring the mechanisms responsible for the removal. IBU was nearly completely removed by all plant species during the 24-day experiment, whereas the IOH removal varied between 13 and 80 %. Typha and Phragmites were the most efficient in removing IBU and IOH, respectively, with first-order removal rate constants of 0.38 and 0.06 day(-1), respectively. The pharmaceuticals were taken up by the roots and translocated to the aerial tissues. However, at the end of the experiment, plant accumulation constituted only up to 1.1 and 5.7 % of the amount of IBU and IOH spiked initially. The data suggest that the plants mainly function by facilitating pharmaceutical degradation in the rhizosphere through release of root exudates.
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15
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Keen OS, Love NG, Aga DS, Linden KG. Biodegradability of iopromide products after UV/H₂O₂ advanced oxidation. Chemosphere 2016; 144:989-994. [PMID: 26433937 DOI: 10.1016/j.chemosphere.2015.09.072] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2015] [Revised: 09/14/2015] [Accepted: 09/18/2015] [Indexed: 06/05/2023]
Abstract
Iopromide is an X-ray and MRI contrast agent that is virtually non-biodegradable and persistent through typical wastewater treatment processes. This study determined whether molecular transformation of iopromide in a UV/H2O2 advanced oxidation process (AOP) can result in biodegradable products. The experiments used iopromide labeled with carbon-14 on the aromatic ring to trace degradation of iopromide through UV/H2O2 advanced oxidation and subsequent biodegradation. The biotransformation assay tracked the formation of radiolabeled (14)CO2 which indicated full mineralization of the molecule. The results indicated that AOP formed biodegradable iopromide products. There was no (14)C released from the pre-AOP samples, but up to 20% of all radiolabeled carbon transformed into (14)CO2 over the course of 42 days of biodegradation after iopromide was exposed to advanced oxidation (compared to 10% transformation in inactivated post-AOP controls). In addition, the quantum yield of photolysis of iopromide was determined using low pressure (LP) and medium pressure (MP) mercury lamps as 0.069 ± 0.005 and 0.080 ± 0.007 respectively. The difference in the quantum yields for the two UV sources was not statistically significant at the 95% confidence interval (p = 0.08), which indicates the equivalency of using LP or MP UV sources for iopromide treatment. The reaction rate between iopromide and hydroxyl radicals was measured to be (2.5 ± 0.2) × 10(9) M(-1) s(-1). These results indicate that direct photolysis is a dominant degradation pathway in UV/H2O2 AOP treatment of iopromide. Other iodinated contrast media may also become biodegradable after exposure to UV or UV/H2O2.
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Affiliation(s)
- Olya S Keen
- Department of Civil, Environmental and Architectural Engineering, University of Colorado, UCB 428, Boulder, CO 80309, USA; Department of Civil and Environmental Engineering, University of North Carolina, 9201 University City Blvd, Charlotte, NC 28223, USA.
| | - Nancy G Love
- Civil and Environmental Engineering Department, University of Michigan, Ann Arbor, MI 48109, USA
| | - Diana S Aga
- Chemistry Department, University at Buffalo, The State University of New York, Buffalo, NY 14260, USA
| | - Karl G Linden
- Department of Civil, Environmental and Architectural Engineering, University of Colorado, UCB 428, Boulder, CO 80309, USA
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Yardman-Frank JM, Mercier RC, Wong CS, Vilay AM. Iohexol transmembrane clearance during modeled continuous renal replacement therapy. Blood Purif 2015; 39:188-192. [PMID: 25765443 DOI: 10.1159/000371755] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2014] [Accepted: 12/23/2014] [Indexed: 11/19/2022]
Abstract
BACKGROUND/AIMS Urea clearance during continuous renal replacement therapy (CRRT) is not representative of middle molecular weight solute clearances. We aimed to characterize iohexol, molecular weight 821 Da, clearance during continuous hemofiltration (CH) and continuous hemodialysis (CHD). METHODS Using an in vitro model, iohexol sieving coefficients (SC) and saturation coefficients (SA) were determined with the M100 membrane at ultrafiltration/dialysate rates of 1, 2, 3, 4, and 6 l/h. Iohexol transmembrane clearance was calculated using the measured SC and SA. RESULTS During CH, the value of iohexol SC remained approximately 1 at all ultrafiltration rates studied. In contrast, during CHD iohexol the mean SA was 1.02 ± 0.05 at a dialysate rate 1 l/h and decreased significantly with higher dialysate rates to a mean SA of 0.57 ± 0.12 at a dialysate rate of 6 l/h. CONCLUSIONS At higher effluent flow rates, CH was more effective in removing iohexol than CHD. CH transmembrane clearance of iohexol appears to approximate the ultrafiltration rate.
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Zachwieja K, Korohoda P, Kwinta-Rybicka J, Miklaszewska M, Moczulska A, Bugajska J, Berska J, Drożdż D, Pietrzyk JA. Which equations should and which should not be employed in calculating eGFR in children? Adv Med Sci 2015; 60:31-40. [PMID: 25265381 DOI: 10.1016/j.advms.2014.08.007] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2014] [Revised: 08/16/2014] [Accepted: 08/20/2014] [Indexed: 12/20/2022]
Abstract
PURPOSE We assessed the reliability of calculating eGFR in children as compared to the iohexol disappearance test (GFR-I), which was performed 417 times in 353 children aged 2 and more. MATERIAL/METHODS eGFR was estimated with equations based on serum creatinine: Schwartz (1: eGFR-Scr), Cockroft-Gault (2: eGFR-CG) and MDRD (3: eGFR-MDRD), and on creatinine clearance (4: eGFR-U), or relying on serum cystatin C: Hoeck (5: eGFR-H), Bokenkamp (6: eGFR-B) and Filler (7: eGFR-F), and on the three Schwartz markers (8: eGFR-S3M). Mean relative error (RE), correlation (R), Bland-Altman analysis and accuracy of GFR-I were studied in all patients and in subgroups: at GFR<60ml/min/1.73m(2); in children aged ≤12 and >12. RESULTS The results by eGFR-Scr, eGFR-S3M demonstrated no statistical difference to GFR-I at GFR<60ml/min/1.73m(2), but underestimated eGFR at higher filtration values by 11.6±15.1% and 19.1±16.4, respectively (p<0.0000). The eGFR-B, eGFR-F and eGFR-MDRD equations illustrated important overestimation of reference GFR results (RE: 84±44.2%; 29.5±27.9%, 35.6±62%; p<0.0000 for all). The MDRD and C-G formulas showed statistically better consistency in children aged >12. A good agreement was achieved by the eGFR-H equation (5.1±21.9%; p<0.0000; R=0.78). CONCLUSIONS (1) Schwartz equations show a good conformity at GFR<60ml/min/1.73m(2), but underestimate the results at higher GFR values. (2) The Bokenkamp equation with original coefficient should not be employed in children. (3) The use of the Hoeck formula in all children and C-G and MDRD formula in children aged >12 is possible. (4) The error of eGFR calculations increases at higher GFR values.
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Affiliation(s)
- Katarzyna Zachwieja
- Department of Pediatric Nephrology, Jagiellonian University Medical College, Cracow, Poland.
| | - Przemysław Korohoda
- Department of Electronics, Faculty of Computer Science, Electronics and Telecommunications, AGH University of Science and Technology, Cracow, Poland
| | - Joanna Kwinta-Rybicka
- Department of Pediatric Nephrology, Children's University Hospital of Cracow, Cracow, Poland
| | - Monika Miklaszewska
- Department of Pediatric Nephrology, Jagiellonian University Medical College, Cracow, Poland
| | - Anna Moczulska
- Department of Pediatric Nephrology, Jagiellonian University Medical College, Cracow, Poland
| | - Jolanta Bugajska
- Clinical Biochemistry Department, Jagiellonian University Medical College, Cracow, Poland
| | - Joanna Berska
- Clinical Biochemistry Department, Jagiellonian University Medical College, Cracow, Poland
| | - Dorota Drożdż
- Department of Pediatric Nephrology, Jagiellonian University Medical College, Cracow, Poland
| | - Jacek A Pietrzyk
- Department of Pediatric Nephrology, Jagiellonian University Medical College, Cracow, Poland
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Djabri A, van't Hoff W, Brock P, Wong ICK, Guy RH, Delgado-Charro MB. Iontophoretic transdermal sampling of iohexol as a non-invasive tool to assess glomerular filtration rate. Pharm Res 2014; 32:590-603. [PMID: 25190007 DOI: 10.1007/s11095-014-1488-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2014] [Accepted: 08/15/2014] [Indexed: 11/26/2022]
Abstract
PURPOSE To explore the potential of non-invasive reverse iontophoresis transdermal extraction of iohexol as a marker of glomerular filtration rate. METHODS A series of in vitro experiments were undertaken to establish the feasibility of iohexol reverse iontophoresis and to determine the optimal conditions for the approach. Subsequently, a pilot study in paediatric patients was performed to provide proof-of-concept. RESULTS The iontophoretic extraction fluxes of iohexol in vitro were proportional to the marker subdermal concentration and the reverse iontophoretic technique was able to track changes dynamically in simulated pharmacokinetic profiles. Reverse iontophoresis sampling was well tolerated by the four paediatric participants. The deduced values of the iohexol terminal elimination rate constant from transdermal reverse iontophoresis sampling agreed with those estimated by conventional blood sampling. CONCLUSIONS Reverse iontophoretic transdermal extraction fluxes mirrored the subdermal concentration profiles of iohexol, a relatively large neutral marker of glomerular filtration both in vitro and in vivo. The efficiency of extraction in vivo was well predicted by the in vitro model used.
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Affiliation(s)
- Asma Djabri
- Department of Pharmacy and Pharmacology, University of Bath, Claverton Down, Bath, BA1 7AY, UK
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Gros M, Cruz-Morato C, Marco-Urrea E, Longrée P, Singer H, Sarrà M, Hollender J, Vicent T, Rodriguez-Mozaz S, Barceló D. Biodegradation of the X-ray contrast agent iopromide and the fluoroquinolone antibiotic ofloxacin by the white rot fungus Trametes versicolor in hospital wastewaters and identification of degradation products. Water Res 2014; 60:228-241. [PMID: 24867600 DOI: 10.1016/j.watres.2014.04.042] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/16/2013] [Revised: 03/03/2014] [Accepted: 04/22/2014] [Indexed: 06/03/2023]
Abstract
This paper describes the degradation of the X-ray contrast agent iopromide (IOP) and the antibiotic ofloxacin (OFLOX) by the white-rot-fungus Trametes versicolor. Batch studies in synthetic medium revealed that between 60 and 80% of IOP and OFLOX were removed when spiked at approximately 12 mg L(-1) and 10 mg L(-1), respectively. A significant number of transformation products (TPs) were identified for both pharmaceuticals, confirming their degradation. IOP TPs were attributed to two principal reactions: (i) sequential deiodination of the aromatic ring and (ii) N-dealkylation of the amide at the hydroxylated side chain of the molecule. On the other hand, OFLOX transformation products were attributed mainly to the oxidation, hydroxylation and cleavage of the piperazine ring. Experiments in 10 L-bioreactor with fungal biomass fluidized by air pulses operated in batch achieved high percentage of degradation of IOP and OFLOX when load with sterile (87% IOP, 98.5% OFLOX) and unsterile (65.4% IOP, 99% OFLOX) hospital wastewater (HWW) at their real concentration (μg L(-1) level). Some of the most relevant IOP and OFLOX TPs identified in synthetic medium were also detected in bioreactor samples. Acute toxicity tests indicated a reduction of the toxicity in the final culture broth from both experiments in synthetic medium and in batch bioreactor.
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Affiliation(s)
- Meritxell Gros
- Catalan Institute for Water Research (ICRA), Scientific and Technological Park of the University of Girona, C/Emili Grahit, 101 Girona, Spain; Commonwealth Scientific and Industrial Research Organization (CSIRO), Land and Water Division, Waite Road Gate 4, Urrbrae, 5064 Adelaide, SA, Australia
| | - Carles Cruz-Morato
- Departament d'Enginyeria Química, Escola d'Enginyeria, Universitat Autònoma de Barcelona (UAB), 08193 Bellaterra, Spain
| | - Ernest Marco-Urrea
- Departament d'Enginyeria Química, Escola d'Enginyeria, Universitat Autònoma de Barcelona (UAB), 08193 Bellaterra, Spain
| | - Philipp Longrée
- Eawag, Swiss Federal Institute of Aquatic Science and Technology, 8600 Dübendorf, Switzerland
| | - Heinz Singer
- Eawag, Swiss Federal Institute of Aquatic Science and Technology, 8600 Dübendorf, Switzerland
| | - Montserrat Sarrà
- Departament d'Enginyeria Química, Escola d'Enginyeria, Universitat Autònoma de Barcelona (UAB), 08193 Bellaterra, Spain
| | - Juliane Hollender
- Eawag, Swiss Federal Institute of Aquatic Science and Technology, 8600 Dübendorf, Switzerland
| | - Teresa Vicent
- Departament d'Enginyeria Química, Escola d'Enginyeria, Universitat Autònoma de Barcelona (UAB), 08193 Bellaterra, Spain
| | - Sara Rodriguez-Mozaz
- Catalan Institute for Water Research (ICRA), Scientific and Technological Park of the University of Girona, C/Emili Grahit, 101 Girona, Spain.
| | - Damià Barceló
- Catalan Institute for Water Research (ICRA), Scientific and Technological Park of the University of Girona, C/Emili Grahit, 101 Girona, Spain; Water and Soil Quality Research Group, Department of Environmental Chemistry IDAEA-CSIC, Jordi Girona 18-26, E-08034 Barcelona, Spain
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Xu BJ, Gao P, Xue G, He MQ, Wu F. [Study on the iopromide-degrading characteristics of strain Pseudomonas sp. I-24 via co-metabolism]. Huan Jing Ke Xue 2014; 35:1443-1448. [PMID: 24946600] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Strain Pseudomonas sp. I-24 (I-24) cannot utilize iopromide (IOP) as the sole carbon and energy source, so different carbon sources (starch, malt sugar, glucose and glycerol) were used as the additional carbon sources to study their effects on I-24 growth and IOP degradation in flask tests. The results showed that the IOP degradation process by I-24 matched the first-order kinetics. Among these four co-substrates, starch was found to be the most efficient to enhance IOP degradation. The corresponding degradation efficiency was as high as 92.7% and the highest enzymatic activity of 0.182 mU appeared in the third day. The optimum starch concentration was 1 g x L(-1). Since glucose and malt sugar better promoted I-24 growth and electron transport system activity (ETSA), indicating that the IOP degradation process would probably be restrained by excess growth, which decreased the degradation efficiency of IOP. In addition, no direct correlation between ETSA and co-metabolism process was found. The detected enzymatic activity of I-24 in control sample indicated that the key enzymes could be still induced in low-concentration of co-substrates.
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Fadrowski JJ, Abraham AG, Navas-Acien A, Guallar E, Weaver VM, Furth SL. Blood lead level and measured glomerular filtration rate in children with chronic kidney disease. Environ Health Perspect 2013; 121:965-70. [PMID: 23694739 PMCID: PMC3734488 DOI: 10.1289/ehp.1205164] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2012] [Accepted: 05/20/2013] [Indexed: 05/24/2023]
Abstract
BACKGROUND The role of environmental exposure to lead as a risk factor for chronic kidney disease (CKD) and its progression remains controversial, and most studies have been limited by a lack of direct glomerular filtration rate (GFR) measurement. OBJECTIVE We evaluated the association between lead exposure and GFR in children with CKD. METHODS In this cross-sectional study, we examined the association between blood lead levels (BLLs) and GFR measured by the plasma disappearance of iohexol among 391 participants in the Chronic Kidney Disease in Children (CKiD) prospective cohort study. RESULTS Median BLL and GFR were 1.2 µg/dL and 44.4 mL/min per 1.73 m2, respectively. The average percent change in GFR for each 1-µg/dL increase in BLL was -2.1 (95% CI: -6.0, 1.8). In analyses stratified by CKD diagnosis, the association between BLL and GFR was stronger among children with glomerular disease underlying CKD; in this group, each 1-µg/dL increase in BLL was associated with a -12.1 (95% CI: -22.2, -1.9) percent change in GFR. In analyses stratified by anemia status, each 1-µg/dL increase in BLL among those with and without anemia was associated with a -0.3 (95% CI: -7.2, 6.6) and -4.6 (95% CI: -8.9, -0.3) percent change in GFR, respectively. CONCLUSIONS There was no significant association between BLL and directly measured GFR in this relatively large cohort of children with CKD, although associations were observed in some subgroups. Longitudinal analyses are needed to examine the temporal relationship between lead and GFR decline, and to further examine the impact of underlying cause of CKD and anemia/hemoglobin status among patients with CKD.
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Affiliation(s)
- Jeffrey J Fadrowski
- Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.
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Liu Y, Hu J, Xu B, He J, Gao P, Liu K, Xue G, Ognier S. Isolation and identification of an iopromide-degrading strain and its application in an A2/O system. Bioresour Technol 2013; 134:36-42. [PMID: 23500557 DOI: 10.1016/j.biortech.2013.02.043] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2013] [Revised: 02/15/2013] [Accepted: 02/16/2013] [Indexed: 06/01/2023]
Abstract
An iopromide (IOPr)-degrading bacterium was isolated from activated sludge of a wastewater treatment plant in Shanghai. Based on its morphology, physiological-biochemical characteristics and a phylogenetic analysis of its 16S rRNA sequence, the bacterium was identified and named as Pseudomonas sp. I-24. The optimum condition for degrading IOPr was at 30°C and pH 7.0. After 5 days, strain I-24 could degrade 30 mg/L IOPr by 99% in a basal salts medium with a 5% (V/V) inoculum and 200 mg/L starch as the primary substrate. When applied to an Anaerobic-Anoxic/Aerobic (A2/O) process, with the coexistence of other bacteria, the strain I-24 got lower (61.3%) IOPr removal, but in two A2/O systems (with and without I-24 inoculation), the CODcr removal were both approximately 95%. The trial dosed with strain I-24 showed better IOPr removal than the un-dosed one. I-24 sustained its abundance in the A2/O system during the experiment.
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Affiliation(s)
- Yanan Liu
- School of Environmental Science and Engineering, Dong Hua University, Shanghai 201620, China.
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Ruggenenti P, Gaspari F, Cannata A, Carrara F, Cella C, Ferrari S, Stucchi N, Prandini S, Ene-Iordache B, Diadei O, Perico N, Ondei P, Pisani A, Buongiorno E, Messa P, Dugo M, Remuzzi G. Measuring and estimating GFR and treatment effect in ADPKD patients: results and implications of a longitudinal cohort study. PLoS One 2012; 7:e32533. [PMID: 22393413 PMCID: PMC3291245 DOI: 10.1371/journal.pone.0032533] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2011] [Accepted: 01/31/2012] [Indexed: 02/08/2023] Open
Abstract
Trials failed to demonstrate protective effects of investigational treatments on glomerular filtration rate (GFR) reduction in Autosomal Dominant Polycystic Kidney Disease (ADPKD). To assess whether above findings were explained by unreliable GFR estimates, in this academic study we compared GFR values centrally measured by iohexol plasma clearance with corresponding values estimated by Chronic Kidney Disease Epidemiology Collaboration (CKD-Epi) and abbreviated Modification of Diet in Renal Disease (aMDRD) formulas in ADPKD patients retrieved from four clinical trials run by a Clinical Research Center and five Nephrology Units in Italy. Measured baseline GFRs and one-year GFR changes averaged 78.6±26.7 and 8.4±10.3 mL/min/1.73 m2 in 111 and 71 ADPKD patients, respectively. CKD-Epi significantly overestimated and aMDRD underestimated baseline GFRs. Less than half estimates deviated by <10% from measured values. One-year estimated GFR changes did not detect measured changes. Both formulas underestimated GFR changes by 50%. Less than 9% of estimates deviated <10% from measured changes. Extent of deviations even exceeded that of measured one-year GFR changes. In ADPKD, prediction formulas unreliably estimate actual GFR values and fail to detect their changes over time. Direct kidney function measurements by appropriate techniques are needed to adequately evaluate treatment effects in clinics and research.
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Affiliation(s)
- Piero Ruggenenti
- Clinical Research Center for Rare Diseases Aldo & Cele Daccò, Mario Negri Institute for Pharmacological Research, Bergamo, Italy
- Unit of Nephrology, Azienda Ospedaliera Ospedali Riuniti di Bergamo, Bergamo, Italy
| | - Flavio Gaspari
- Clinical Research Center for Rare Diseases Aldo & Cele Daccò, Mario Negri Institute for Pharmacological Research, Bergamo, Italy
| | - Antonio Cannata
- Clinical Research Center for Rare Diseases Aldo & Cele Daccò, Mario Negri Institute for Pharmacological Research, Bergamo, Italy
| | - Fabiola Carrara
- Clinical Research Center for Rare Diseases Aldo & Cele Daccò, Mario Negri Institute for Pharmacological Research, Bergamo, Italy
| | - Claudia Cella
- Clinical Research Center for Rare Diseases Aldo & Cele Daccò, Mario Negri Institute for Pharmacological Research, Bergamo, Italy
| | - Silvia Ferrari
- Clinical Research Center for Rare Diseases Aldo & Cele Daccò, Mario Negri Institute for Pharmacological Research, Bergamo, Italy
| | - Nadia Stucchi
- Clinical Research Center for Rare Diseases Aldo & Cele Daccò, Mario Negri Institute for Pharmacological Research, Bergamo, Italy
| | - Silvia Prandini
- Clinical Research Center for Rare Diseases Aldo & Cele Daccò, Mario Negri Institute for Pharmacological Research, Bergamo, Italy
| | - Bogdan Ene-Iordache
- Clinical Research Center for Rare Diseases Aldo & Cele Daccò, Mario Negri Institute for Pharmacological Research, Bergamo, Italy
| | - Olimpia Diadei
- Clinical Research Center for Rare Diseases Aldo & Cele Daccò, Mario Negri Institute for Pharmacological Research, Bergamo, Italy
| | - Norberto Perico
- Clinical Research Center for Rare Diseases Aldo & Cele Daccò, Mario Negri Institute for Pharmacological Research, Bergamo, Italy
| | - Patrizia Ondei
- Unit of Nephrology, Azienda Ospedaliera Ospedali Riuniti di Bergamo, Bergamo, Italy
| | - Antonio Pisani
- Azienda Ospedaliera Universitaria Federico II, Napoli, Italy
| | | | - Piergiorgio Messa
- Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milano, Italy
| | - Mauro Dugo
- Azienda ULSS 9 – Ospedale S. Maria di Ca' Foncello, Treviso, Italy
| | - Giuseppe Remuzzi
- Clinical Research Center for Rare Diseases Aldo & Cele Daccò, Mario Negri Institute for Pharmacological Research, Bergamo, Italy
- Unit of Nephrology, Azienda Ospedaliera Ospedali Riuniti di Bergamo, Bergamo, Italy
- * E-mail:
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Khunjar WO, Love NG. Sorption of carbamazepine, 17α-ethinylestradiol, iopromide and trimethoprim to biomass involves interactions with exocellular polymeric substances. Chemosphere 2011; 82:917-22. [PMID: 21111443 DOI: 10.1016/j.chemosphere.2010.10.046] [Citation(s) in RCA: 6] [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] [Received: 04/19/2010] [Revised: 10/11/2010] [Accepted: 10/12/2010] [Indexed: 05/06/2023]
Abstract
The sorption of carbamazepine (CBZ), iopromide (IOP), trimethoprim (TMP) and 17α-ethinylestradiol (EE2) was evaluated using four biomass types (pure ammonia oxidizing bacterial culture, two heterotrophic enrichment cultures with varying levels of oxygenase activity, and a full-scale nitrifying activated sludge (NAS) culture). CBZ and IOP did not sorb to the four biomass types. EE2 did not sorb to the pure culture but sorbed significantly to the heterotrophic cultures and NAS. TMP sorbed to the heterotrophic cultures and NAS, and was not evaluated for the pure culture. Three floc characteristics (hydrophobicity, median particle size, organic matter content) correlated moderately well with the EE2 organic matter sorption coefficient (KOM,EE2). Zeta potential did not correlate well with KOM,EE2 but did with KOM,TMP, indicating that TMP sorption is more influenced by electrostatic factors than EE2. Once divalent cation-linked exocellular polymeric substances (EPS) were removed from flocs, EE2 and TMP sorption to the non-EPS (cellular) fraction decreased by approximately 50%. The correlation between KOM,EE2 for the non-EPS cellular fraction deteriorated while the correlation between KOM,TMP improved. EE2 seemed to sorb more strongly to EPS protein whereas TMP sorbed equally to polysaccharide and protein EPS. Attempts to develop predictive models were not successful. Pharmaceuticals that sorbed to biomass samples underwent biodegradation whereas those that did not sorb were not biodegraded, suggesting a relationship between sorption and pharmaceutical biotransformation.
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Affiliation(s)
- Wendell O Khunjar
- Charles E. Via Jr. Department of Civil and Environmental Engineering, Virginia Polytechnic Institute and State University, 418 Durham Hall (0246), Blacksburg, VA 24061, United States
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Mu Y, Radjenovic J, Shen J, Rozendal RA, Rabaey K, Keller J. Dehalogenation of iodinated X-ray contrast media in a bioelectrochemical system. Environ Sci Technol 2011; 45:782-788. [PMID: 21141818 DOI: 10.1021/es1022812] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Iodinated X-ray contrast media (ICM) are only to a limited extent removed from conventional wastewater treatment plants, due to their high recalcitrance. This work reports on the cathodic dehalogenation of the ICM iopromide in a bioelectrochemical system (BES), fed with acetate at the anode and iopromide at the cathode. When the granular graphite cathode potential was decreased from -500 to -850 mV vs standard hydrogen electrode (SHE), the iopromide removal and the iodide release rates increased from 0 to 4.62 ± 0.01 mmol m(-3) TCC d(-1) and 0 to 13.4 ± 0.16 mmol m(-3) TCC d(-1) (Total Cathodic Compartment, TCC) respectively. Correspondingly, the power consumption increased from 0.4 ± 1 to 20.5 ± 3.3 W m(-3) TCC. The Coulombic efficiency of the iopromide dehalogenation at the cathode was less than 1%, while the Coulombic efficiency of the acetate oxidation at the anode was lower than 50% at various granular graphite cathode potentials. The results suggest that iopromide could be completely dehalogenated in BESs when the granular graphite cathode potential was controlled at -800 mV vs SHE or lower. This finding was further confirmed using mass spectrometry to identify the dehalogenated intermediates and products of iopromide in BESs. Kinetic analysis indicates that iopromide dehalogenation in batch experiments can be described by a first-order model at various cathode potentials. This work demonstrates that the BESs have a potential for efficient dehalogenation of ICM from wastewater or environmental streams.
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Affiliation(s)
- Yang Mu
- Advanced Water Management Centre, The University of Queensland, St. Lucia, Queensland, Australia.
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Zipor G, Brocard C, Gerst JE. Isolation of mRNAs encoding peroxisomal proteins from yeast using a combined cell fractionation and affinity purification procedure. Methods Mol Biol 2011; 714:323-33. [PMID: 21431750 DOI: 10.1007/978-1-61779-005-8_20] [Citation(s) in RCA: 2] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/05/2022]
Abstract
Targeted mRNA localization to distinct subcellular sites occurs throughout the eukaryotes and presumably allows for the localized translation of proteins near their site of function. Specific mRNAs have been localized in cells using a variety of reliable methods, such as fluorescence in situ hybridization with labeled RNA probes, mRNA tagging using RNA aptamers and fluorescent proteins that recognize these aptamers, and quenched fluorescent RNA probes that become activated upon binding to mRNAs. However, fluorescence-based RNA localization studies can be strengthened when coupled with cell fractionation and membrane isolation techniques in order to identify mRNAs associated with specific organelles or other subcellular structures. Here we describe a novel method to isolate mRNAs associated with peroxisomes in the yeast, Saccharomyces cerevisiae. This method employs a combination of density gradient centrifugation and affinity purification to yield a highly enriched peroxisome fraction suitable for RNA isolation and reverse transcription-polymerase chain reaction detection of mRNAs bound to peroxisome membranes. The method is presented for the analysis of peroxisome-associated mRNAs; however it is applicable to studies on other subcellular compartments.
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Affiliation(s)
- Gadi Zipor
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
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Korohoda P, Zachwieja K, Pietrzyk JA, Sułowicz W. [GFR estimation based upon cystatin C concentration as a substance marker--proposal of a new formula]. Przegl Lek 2009; 66:1020-1026. [PMID: 20514898] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Glomerular filtration rate (GFR) estimation is very important for evaluation of kidney function. Its calculation is based upon a 24 hour urine collection and serum creatinine concentration values or on the basis of developed for this purpose numerous formulas with special attention dedicated to the abbreviated MDRD formula and Cockcroft-Gault formulas for adults and Schwartz et al. and Counahan et al. formulas for children. Future expectations are related to GFR estimation based on serum cystatin C concentration and formulas specially developed for this cause. The aim of the study was the comparative analysis of GFR results based on Filler's and Lapage's, Grubb's et al. and Schwartz's et al. formulas and reference values obtained in 93 patients after measuring iohexol concentration after its single injection. Significant differences between the results obtained from employed formulas for high, as well as for low values of GFR were shown, respectively. Serial calculations were performed allowing to finding out a new prescription for GFR calculation. A new formula for GFR calculation based on cystatin C concentration: GFR = -7.28+82.29 x C(-1) was proposed.
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Danila D, Partha R, Elrod DB, Lackey M, Casscells SW, Conyers JL. Antibody-labeled liposomes for CT imaging of atherosclerotic plaques: in vitro investigation of an anti-ICAM antibody-labeled liposome containing iohexol for molecular imaging of atherosclerotic plaques via computed tomography. Tex Heart Inst J 2009; 36:393-403. [PMID: 19876414 PMCID: PMC2763481] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
We evaluated the specific binding of anti-intercellular adhesion molecule 1 (ICAM-1) conjugated liposomes (immunoliposomes, or ILs) to activated human coronary artery endothelial cells (HCAEC) with the purpose of designing a computed tomographic imaging agent for early detection of atherosclerotic plaques. Covalent attachment of anti-ICAM-1 monoclonal antibodies to pre-formed liposomes stabilized with polyethylene glycol yielded ILs, with a coupling efficiency of the ICAM-1 to the liposomes of 10% to 24%. The anti-ICAM-1-labeled ILs had an average diameter of 136 nm as determined by dynamic light-scattering and cryogenic electron microscopy. The ILs' encapsulation of 5-[N-acetyl-(2,3-dihydroxypropyl)-amino)-N, N'-bis(2,3-dihydroxypropyl)-2,4,6-triiodo-benzene-1,3-dicarboxamide (iohexol) was determined to be 18% to 19% by a dialysis technique coupled with ultraviolet detection of free iohexol. This encapsulation corresponded to 30 to 38 mg iodine per mL IL solution, and the ILs exhibited 91% to 98.5% iohexol retention at room temperature and under physiologic conditions. The specific binding of the ILs to cultured, activated HCAEC was measured using flow cytometry, enzyme-linked immunosorbent assays, and fluorescence microscopy. The immunosorbent assays demonstrated the specificity of binding of anti-ICAM-1 to ICAM-1 compared with control studies using nonspecific immunoglobulin G-labeled ILs. Flow cytometry and fluorescence microscopy experiments demonstrated the expression of ICAM-1 on the surface of activated HCAEC. Therefore, our iohexol-filled ILs demonstrated potential for implementation in computed tomographic angiography to noninvasively detect atherosclerotic plaques that are prone to rupture.
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Affiliation(s)
- Delia Danila
- Department of Internal Medicine, Division of Cardiology, The University of Texas Health Science Center at Houston, Houston, Texas 77030, USA
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Schulz M, Löffler D, Wagner M, Ternes TA. Transformation of the X-ray contrast medium iopromide in soil and biological wastewater treatment. Environ Sci Technol 2008; 42:7207-17. [PMID: 18939548 DOI: 10.1021/es800789r] [Citation(s) in RCA: 97] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
In water/soil systems, the iodinated contrast medium iopromide was quantitatively biotransformed into several transformation products (TPs). Twelve TPs were identified via HPLC-UV and LC tandem MS. The chemical structures of the TPs were elucidated via fragmentation in MS2 and MS3 of LC tandem MS with a linear ion trap and 1H and 13C NMR analyses. All TPs exhibited transformations at the side chains containing either carboxylic moieties and/or primary and secondary amide moieties, while the triiodoisophthalic acid structure remained unaltered. A transformation pathway was proposed based on the sequence of TP formation in aerobic batch experiments. Additionally, the occurrence of iopromide TPs was investigated in native water samples. All TPs identified were found in municipal WWTP effluents because of their formation during biological wastewater treatment with maximum concentrations of up to 3.7 +/- 0.9 microg/L (TP 819). Predominantly, those TPs were present at higher concentrations in WWTP effluents which were formed at the beginning of the transformation pathway. Furthermore, four TPs formed at the end of the transformation pathway (TP 759, 701A/B, and 643) were also found in bank filtrate up to 0.050 microg/L and in groundwater of an wastewater irrigation area up to 4.6 microg/L.
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Affiliation(s)
- Manoj Schulz
- Federal Institute of Hydrology (BFG), Am Mainzer Tor 1, D-56068 Koblenz, Germany
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Hansson LO, Wadström J, Lipcsey M, Biglarnia A, Larsson A. [Current Swedish renal function tests must be better. Uncertain diagnosis with routine formulas--great risk of wrong drug dosages]. Lakartidningen 2008; 105:731-734. [PMID: 18422239] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
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Björk J, Bäck SE, Sterner G, Carlson J, Lindstrom V, Bakoush O, Simonsson P, Grubb A, Nyman U. Prediction of relative glomerular filtration rate in adults: new improved equations based on Swedish Caucasians and standardized plasma-creatinine assays. Scand J Clin Lab Invest 2008; 67:678-95. [PMID: 17852799 DOI: 10.1080/00365510701326891] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
OBJECTIVE To evaluate newly developed equations predicting relative glomerular filtration rate(GFR) in adult Swedish Caucasians and to compare with the Modification of Diet in Renal Disease(MDRD) and Mayo Clinic equations using enzymatic and zero-calibrated plasma creatinine assays. MATERIAL AND METHODS GFR was measured with iohexol clearance adjusted to 1.73 m(2). One population sample (n=436/Lund) was used to derive an equation based on plasma-creatinine/age/gender, and a second with the addition of lean body mass (LBM). Both equations were validated in a separate sample (n=414/Malmö). The coefficients of the equations were eventually fine-tuned using all 850 patients and yielding Lund-Malmö equations without (LM) and with LBM-term (LM(LBM)). Their performance was compared with the MDRD(CC) (conventional creatinine calibration), MDRD(IDMS) (isotope dilution mass spectroscopy traceable calibration) and Mayo Clinic equations. RESULTS The Lund equations performed similarly in both samples. In the combined set, the Mayo Clinic/MDRD(CC) resulted in +19.0/+10.2 % median bias, while bias for the other equations was < 10 %. LM(LBM) had the highest accuracy (86 % of estimates within 30 % of measured GFR), significantly (p < 0.001) better than for MDRD(IDMS) (80 %). In men with BMI < 20 kg/m(2), MDRD(IDMS)/LM had +46 %/+19 % median bias. MDRD(IDMS) also overestimated GFR by 22 %/14 % in men/women above 80 years of age. The LM(LBM) equation had < 10 % bias irrespective of BMI, age or GFR except for a 15 % negative bias at GFR > 90 mL/min/1.73 m(2). CONCLUSION The newly developed Lund-Malmö equations for GFR estimation performed better than the MDRD(IDMS) and Mayo Clinic equations in a Swedish Caucasian sample. Inclusion of an LBM term improved performance markedly in certain subgroups.
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Affiliation(s)
- J Björk
- Competence Centre for Clinical Research, University Hospital, Lund, Sweden
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Abstract
Contrast-induced nephropathy (CIN) after angiographic procedures results in significant morbidity, mortality, and costs. Given the limitations of current prophylactic measures, we have tested the hypothesis that the majority of the contrast injected into a coronary artery can be captured from the coronary sinus before it enters the systemic circulation. The current study involves coronary venous capture after coronary angiography in dogs with determination of contrast capture using quantitative fluoroscopy. Venous contrast capture (VCC) was achieved with a balloon tipped through lumen catheter introduced into the coronary sinus via the superior vena cava. After selective injection of iohexol contrast into the left main coronary artery, the coronary sinus was balloon occluded in order to capture all contrast. The venous blood was subsequently withdrawn from the coronary sinus catheter, and then the balloon was deflated. By quantitative fluoroscopy we could demonstrate that an average 70 +/- 6% of the injected contrast could be captured without complications. Coronary sinus VCC is a novel approach to remove the majority of contrast selectively injected into coronary arteries. As an adjunct procedure in coronary angiography, VCC has the potential to significantly reduce the risk of CIN in patients at risk.
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Affiliation(s)
- Markus Meyer
- Division of Cardiology, College of Medicine, University of Vermont, Burlington, Vermont, USA.
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Michel AD, Chambers LJ, Clay WC, Condreay JP, Walter DS, Chessell IP. Direct labelling of the human P2X7 receptor and identification of positive and negative cooperativity of binding. Br J Pharmacol 2007; 151:103-14. [PMID: 17339830 PMCID: PMC2012979 DOI: 10.1038/sj.bjp.0707196] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
BACKGROUND AND PURPOSE The P2X(7) receptor exhibits complex pharmacological properties. In this study, binding of a [(3)H]-labelled P2X(7) receptor antagonist to human P2X(7) receptors has been examined to further understand ligand interactions with this receptor. EXPERIMENTAL APPROACH The P2X(7) receptor antagonist, N-[2-({2-[(2-hydroxyethyl)amino]ethyl}amino)-5-quinolinyl]-2-tricyclo[3.3.1.1(3,7)]dec-1-ylacetamide (compound-17), was radiolabelled with tritium and binding studies were performed using membranes prepared from U-2 OS or HEK293 cells expressing human recombinant P2X(7) receptors. KEY RESULTS Binding of [(3)H]-compound-17 was higher in membranes prepared from cells expressing P2X(7) receptors than from control cells and was inhibited by ATP suggesting labelled sites represented human P2X(7) receptors. Binding was reversible, saturable and modulated by P2X(7) receptor ligands (Brilliant Blue G, KN62, ATP, decavanadate). Furthermore, ATP potency was reduced in the presence of divalent cations or NaCl. Radioligand binding exhibited both positive and negative cooperativity. Positive cooperativity was evident from bell shaped Scatchard plots, reduction in radioligand dissociation rate by unlabelled compound-17 and enhancement of radioligand binding by KN62 and unlabelled compound-17. ATP and decavanadate inhibited binding in a negative cooperative manner as they enhanced radioligand dissociation. CONCLUSIONS These data demonstrate that human P2X(7) receptors can be directly labelled and provide novel insights into receptor function. The positive cooperativity observed suggests that binding of compound-17 to one subunit in the P2X(7) receptor complex enhances subsequent binding to other P2X(7) subunits in the same complex. The negative cooperative effects of ATP suggest that ATP and compound-17 bind at separate, interacting, sites on the P2X(7) receptor.
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Affiliation(s)
- A D Michel
- Neurology & GI Centre of Excellence for Drug Discovery, GlaxoSmithKline Research and Development Limited, Harlow, Essex, UK.
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Abstract
Iopromide (an X-ray contrast agent) and trimethoprim (an antibacterial drug) are frequently detected pharmaceuticals in effluents of wastewater treatment plants (WWTPs) and in surface waters due to their persistence and high usage. Laboratory-scale experiments showed that a significantly higher removal rate in nitrifying activated sludge as compared to conventional activated sludge was observed for both iopromide and trimethoprim. When the activity of the nitrifying bacteria was inhibited, the percent removal of iopromide decreased from 97 to 86% while trimethoprim removal decreased from 70 to 25%. The metabolite of iopromide identified when nitrification was not inhibited was a dehydroxylated iopromide at the two side chains. However, when the nitrifying bacteria were inhibited the metabolite identified was a carboxylate, formed during the oxidation of the primary alcohol on the side chain of iopromide. These results suggest that the nitrifying bacteria are important in the observed biodegradation of iopromide in the activated sludge with higher solid retention time (SRT). Results from the laboratory-scale study were corroborated by the observed removal efficiencies in a full-scale municipal WWTP, which showed that iopromide (ranging from 0.10 to 0.27 microg/L) and trimethoprim (ranging from 0.0.08 to 0.53 microg/L) were removed more effectively in the nitrifying activate sludge which has a higher SRT (49 days) than in the conventional activated sludge (SRT of 6 days). In nitrifying activated sludge, the percent removal of iopromide in the WWTP reached 61%, while in conventional activated sludge, average removal was negligible. For trimethoprim, removal was limited to about 1% in the conventional activated sludge, while in the nitrifying activated sludge, the removal was increased to 50%.
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Affiliation(s)
- Angela L Batt
- Department of Chemistry, The State University of New York at Buffalo, 608 Natural Sciences Complex, Buffalo, New York 14260-3000, USA
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Michel A, Jacob GB. Comment to "Transplacental passage of a nonionic contrast agent". Eur J Pediatr 2006; 165:667; author reply 668-9. [PMID: 16532319 DOI: 10.1007/s00431-005-0071-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/08/2005] [Accepted: 12/15/2005] [Indexed: 10/24/2022]
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Pérez S, Eichhorn P, Celiz MD, Aga DS. Structural Characterization of Metabolites of the X-ray Contrast Agent Iopromide in Activated Sludge Using Ion Trap Mass Spectrometry. Anal Chem 2006; 78:1866-74. [PMID: 16536422 DOI: 10.1021/ac0518809] [Citation(s) in RCA: 83] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Identification of degradation products of environmental contaminants is a challenging task because not only are they present in very low concentrations but they are also mixed with complex matrixes that interfere with detection. This work illustrates a simple approach using ion trap mass spectrometry combined with H/D-exchange experiments to elucidate the structures of iopromide metabolites formed during biodegradation in activated sludge. Iopromide is an X-ray contrast agent that has been detected frequently in effluents of wastewater treatment plants and in surface waters due to its persistence and high usage. Three metabolites produced by oxidation of the primary alcohols (forming carboxylates) on the side chains of iopromide were identified in a batch reactor with mixed liquor from a conventional activated sludge. Derivatization of the carboxylic acid to form a methyl ester and interpretation of the MS2 data of this derivative aided in the confirmation of the identities of these metabolites. Furthermore, one metabolite formed by dehydroxylation at the two side chains was identified in a batch reactor with mixed liquor from a nitrifying activated sludge. The MS2 fragmentation pattern of iopromide and its metabolites revealed that the iodinated ring remains intact and that minor transformations in the structure occur during biodegradation of iopromide in biological wastewater treatment plants.
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Affiliation(s)
- Sandra Pérez
- Chemistry Department, State University of New York at Buffalo, 611 Natural Sciences Complex, Buffalo, New York 14260, USA
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Vanhaesebrouck P, Verstraete AG, De Praeter C, Smets K, Zecic A, Craen M. Transplacental passage of a nonionic contrast agent. Eur J Pediatr 2005; 164:408-10. [PMID: 15798909 DOI: 10.1007/s00431-005-1659-2] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/04/2005] [Accepted: 02/16/2005] [Indexed: 01/28/2023]
Abstract
UNLABELLED We report the presence of iopromide in the bowel and urine of a preterm infant, born 10 days after intravenous administration of the nonionic monomer to his mother. Excessive urinary iodine excretion and borderline hyperthyrotropinaemia were observed in the infant. Moreover, crossing of the fetal blood-brain barrier was demonstrated by detection of the angiographic material in CSF and thus direct fetal neurotoxic effects cannot be excluded. CONCLUSION These widely used contrast media may cross the placenta and accumulate in various fetal tissues in significant amounts causing possible neonatal toxicity. Therefore the perinatal safety of these diagnostic agents should at least be questioned.
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Affiliation(s)
- Piet Vanhaesebrouck
- Department of Neonatology, Ghent University Hospital, De Pintelaan 185, 9000 Ghent, Belgium.
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Schumacher J, Pi YZ, Jekel M. Ozonation of persistent DOC in municipal WWTP effluent for groundwater recharge. Water Sci Technol 2004; 49:305-310. [PMID: 15077988] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Groundwater recharge is becoming common in areas where the withdrawal of groundwater exceeds its natural recharge. Wastewater treatment plant (WWTP) effluent can be used for this purpose, but persistent organic compounds can only be partly removed during soil passage. This point was confirmed in degradation tests using soil columns in which the DOC of a membrane bioreactor (MBR) permeate could only be reduced by 15% and adsorbable organic iodine (AOI) by 2%. However, ozonation was found to improve biodegradation and at the maximum formation of biodegradable DOC at 2.5 mg O3/mg DOC0, the DOC values of MBR permeate (11-13 mg/L) could be reduced in aerobic degradation batch tests to the DOC of Berlin drinking water (3-5 mg/L). A combination of ozonation at 1.9 g O3/g DOC0 with soil passage could adjust DOC, UVA254, colour (436 nm) and the molecular DOC size distribution to drinking water ranges, but AOI was only reduced from 143 microg/L to 92 microg/L and remained high compared to tap water (2.2 microg/L). The extremely persistent X-ray contrast compound iopromide, which represents part of AOI, was spiked into MBR permeate at a low concentration. Iopromide was reduced by 88% during ozonation, but AOI only decreased by 23% indicating that a transformation, but not a mineralization, of iodinated organic compounds occurs.
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Affiliation(s)
- J Schumacher
- Department of Water Quality Control, Secr. KF4, Fasanenstrasse 1A, Technical University Berlin, 10623 Berlin, Germany.
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Abstract
BACKGROUND 3-Hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase inhibitors increase renal blood flow independent of their lipid-lowering properties. In organ transplantation, the calcineurin inhibitor cyclosporine A (CyA) is the immunosuppressant of choice. However, its renal vasoconstrictor properties limit its use. This study aimed to determine the effect of an HMG-CoA reductase inhibitor, simvastatin (Zocor), on renal function in rats after ischemia/reperfusion injury (I/R) with concomitant CyA treatment. METHODS Male Wistar rats (250 g) were anesthetized and the suprarenal aorta clamped for 40 minutes. The right kidney was removed. After recovery, the rats were divided into 5 groups: (1) control rats, no ischemia, no treatment; (2) ischemia with no treatment; (3) ischemia plus CyA only; (4) ischemia plus CyA and low-dose simvastatin; and (5) ischemia plus CyA and high-dose simvastatin. Five to 7 days after I/R injury, glomerular filtration rate (GFR) was determined using urinary iohexol clearance. RESULTS The GFR values (mL/min) for all 5 groups were as follows: (1) 1.23 +/- 0.08; (2) 1.05 +/- 0.10; (3) 0.44 +/- 0.06 (P < 0.05 versus groups 1, 2, and 5; one-way analysis of variance); (4) 0.51 +/- 0.04 (P < 0.05 versus groups 1, 2, and 5; one-way analysis of variance); and (5) 0.85 +/- 0.11. CONCLUSIONS After I/R injury and cyclosporine treatment, simvastatin preserved renal function compared with cyclosporine treatment alone because it may not have a direct vasoconstrictor effect on the renal microcirculation. In fact, it may exhibit vasodilator properties on the renal microcirculation mediated by nitric oxide.
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Affiliation(s)
- Sharon R Inman
- College of Osteopathic Medicine, Ohio University, Athens, OH 45701, USA.
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Christensson A, Ekberg J, Grubb A, Ekberg H, Lindström V, Lilja H. Serum cystatin C is a more sensitive and more accurate marker of glomerular filtration rate than enzymatic measurements of creatinine in renal transplantation. Nephron Physiol 2003; 94:p19-27. [PMID: 12845219 DOI: 10.1159/000071287] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2002] [Accepted: 04/01/2003] [Indexed: 11/19/2022]
Abstract
BACKGROUND/AIMS Serum creatinine has several drawbacks as marker of glomerular filtration rate (GFR), and therefore serum cystatin C has been proposed as a more optimal GFR marker. Previous reports have suggested benefits of serum cystatin C measurements in patients with renal transplants. The purpose of the present study was to evaluate the diagnostic accuracy of cystatin C measurements compared with enzymatic creatinine measurements as serum markers of GFR (established from plasma clearance of iohexol) in a large cohort of stable renal transplant recipients and in the early postoperative phase. METHODS Renal transplant patients (n = 125) with stable graft function were evaluated from reciprocals of serum creatinine and cystatin C compared with iohexol clearance. Fourteen patients were examined immediately after the onset of renal function. Cystatin C was measured by a particle-enhanced turbidimetric method and creatinine by an enzymatic method. RESULTS In stable renal transplant recipients, serum cystatin C showed a significantly (p = 0.033) closer correlation (r = 0.89 or 79% co-variance) with iohexol clearance than did serum creatinine (r = 0.81 or 66% co-variance). Using the chi(2) test and a cut-off at 60 ml/min/1.73 m(2), serum cystatin C levels demonstrated significantly higher sensitivity for early GFR impairment (p = 0.0045) compared with serum creatinine measurements. On the first day after transplantation, serum cystatin C fell more rapidly than serum creatinine. CONCLUSION Serum cystatin C levels correlate significantly closer to accurate measurements of GFR and are significantly more sensitive to detect early GFR impairment than enzymatic measurements of creatinine in serum.
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Affiliation(s)
- Anders Christensson
- Department of Nephrology and Transplantation, Malmö University Hospital, Malmö, Sweden.
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Steger-Hartmann T, Länge R, Schweinfurth H, Tschampel M, Rehmann I. Investigations into the environmental fate and effects of iopromide (ultravist), a widely used iodinated X-ray contrast medium. Water Res 2002; 36:266-74. [PMID: 11766804 DOI: 10.1016/s0043-1354(01)00241-x] [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] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
lodinated X-ray contrast media are pharmaceuticals which are biologically inert and metabolically stable during their passage through the body and are excreted almost completely within a day into waste water. They are not readily biodegradable. However, in a test system simulating sewage treatment, we were able to show that the model compound iopromide (N,N'-bis(2,3-dihydroxypropyl)-2,4,6-triiodo-5-methoxyacetylamino-N-methyliso-phthalamide) was amenable to primary degradation. The resulting degradation product (5-amino-N'N'-bis(2,3-dihydroxypropyl)-2,4,6-triiodo-N-methyliso-phthalamide) showed a faster photolysis than the parent compound. Additionally this product was further degraded in a test system simulating surface water conditions. Short-term toxicity of the primary degradation product was low, i.e. no effects on any of various aquatic species could be found even at concentrations of 1 gl(-1). Additionally no chronic toxicity of the degradation product was observed in an early-life stage test with zebrafish at the highest tested concentration of 100mgl(-1). Based on the results from model systems a degradation pathway for iopromide is postulated. Though further work showing the transferability of the laboratory results to environmental conditions is necessary the presently available information on the environmental fate and effects of iopromide and its degradation products do not provide evidence of a risk for aquatic life caused by the introduction of this contrast medium into waste water.
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Halme L, Turunen U, Tuominen J, Forsström T, Turpeinen U. Comparison of iohexol and lactulose-mannitol tests as markers of disease activity in patients with inflammatory bowel disease. Scand J Clin Lab Invest 2000; 60:695-701. [PMID: 11218152 DOI: 10.1080/00365510050216420] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
Abstract
Increased intestinal permeability has been proposed as one aetiological factor for inflammatory bowel diseases (IBD). We have previously found that intestinal permeability of a water-soluble contrast medium, iohexol, correlates with disease activity. The objective was to compare the iohexol test with the lactulose-mannitol ratio, which is a more extensively studied permeability marker, in patients with active IBD. Urinary excretion of iohexol was compared to the lactulose-mannitol ratio in 22 patients with an exacerbation of IBD and in 10 healthy controls. Median intestinal absorption of iohexol was 0.64% (range 0.13-3.8%) in the 22 patients and 0.3% (range 0.15-0.54%) in the controls (p = 0.016), whereas the median lactulose-mannitol ratio was 0.037 (range 0.01-0.260) in patients and 0.03 (range 0.004-0.063) in controls (N.S.). Correlation between urinary excretion of iohexol and lactulose-mannitol ratio was positive (R = +0.41, p = 0.018). The urinary excretion of iohexol correlated positively with endoscopic disease activity (R = +0.74, p < 0.001) and the modified Harvey-Bradshaw index (R = +0.44, p = 0.04). The lactulose-mannitol ratio correlated positively with endoscopic disease activity (R = +0.44, p = 0.05), but correlations with clinical index or c-reactive protein were poor. In conclusion, the iohexol test is a superior activity marker compared to the lactulose-mannitol ratio which probably reflects, instead, some pathogenic property of IBD.
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Affiliation(s)
- L Halme
- Fourth Department of Surgery, Helsinki University Hospital, Finland.
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Abstract
RATIONALE AND OBJECTIVES Most radiographic contrast media (CM) are hyperosmotic and pose an osmotic threat to cells they are in contact with. To study these effects at the cellular level, cell volume regulatory mechanisms were observed in proximal renal tubules following exposure to the CM iohexol, ioxaglate, and iodixanol. MATERIALS AND METHODS Isolated renal tubules from trout (Salmo trutta) were exposed to 5% vol/vol iohexol (326 mOsm), ioxaglate (314 mOsm), or iodixanol (300 mOsm) or mannitol (to achieve the same osmolalities), and cell volume changes were observed videometrically. RESULTS Iohexol and ioxaglate solutions induced a rapid shrinkage (12%-13%) not followed by cell volume regulation. Without CM (same osmolality), the cells shrank 11% but then showed a 77%-88% volume recovery. This reswelling was inhibited by 55% with the Na+, K+, Cl- symporter inhibitor bumetanide (50 micromol/L). Iodixanol did not significantly affect cell volume. Tubules preincubated with CM or mannitol were then stimulated with a hypoosmotic Ringer solution (160 mOsm) resulting in a 26%-36% cellular volume increase. Compared with results of experiments without mannitol and CM, preexposure to iohexol or ioxaglate almost completely inhibited the expected regulatory shrinkage phase, while previous exposure to hyperosmotic solutions with mannitol reduced the shrinkage response by 40%-53%. CONCLUSION In this system, the hyperosmotic iohexol and ioxaglate cause cell shrinkage followed by an impaired cell volume regulatory response. Exposure to these two CM also inhibits cell volume regulation on hypoosmotic stimulation. The isosmotic iodixanol has no such effects. These changes appear to some extent to be a result of the CM's degree of hyperosmolality, but this property alone does not explain these findings.
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Affiliation(s)
- H K Galtung
- Department of Biology, University of Oslo, Norway
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Abstract
The degradation of the iodinated contrast media diatrizoate and iopromide was investigated in laboratory tests. With regard to the expected behaviour of the contrast media in the environment, test systems with activated sludge, river water and river water plus sediment were established. In some of the experiments 14C-labelled contrast media were used to study degradation at low concentrations and to detect the transformation products. Degradation by as well as binding to aerobic-activated sludge of diatrizoate was poor, suggesting that this substance is hardly retained in sewage treatment plants. In systems with river water and sediment deacetylation of diatrizoate started after a lag period of 3 weeks and followed first order kinetics with rate constants of approximately 0.15 day-1. Two metabolites were formed that were stable until day 200 of aerobic incubation. Finally, further transformation of the aerobic metabolites was observed under anoxic conditions. In activated sludge, approximately 85% of iopromide were transformed into two metabolites. Like the parent compound they were highly hydrophilic and less than 16% were bound to sludge solids. In water/sediment systems, disappearance of iopromide started spontaneously with a first order constant of 0.04 day-1. One metabolite that was stable throughout the incubation period was formed with a delay of 20 days. In river water the concentration-dependent disappearance of iopromide was studied. The shortest half-life was 3.1 days at a concentration of 16.0 mumol l-1 and increased at concentrations below and above this value. The metabolites of iopromide were not identified, but partial deiodination of iopromide was shown. Mineralisation of the two contrast media or their metabolites to carbon dioxide was not observed.
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Affiliation(s)
- W Kalsch
- ECT Oekotoxikologie GmbH, Floersheim, Germany.
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Prangé T, Neuman A, Corot C, Meyer D. Study of the complex between the contrast agent Iobitridol (Xenetix) and Elastase (PPE): a model for hydrophobic site protection in drug-protein interactions. Pharm Res 1997; 14:1713-7. [PMID: 9453058 DOI: 10.1023/a:1012123628123] [Citation(s) in RCA: 4] [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] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
PURPOSE The concept of Hydrophilic Sphere Stabilization, or Hydrophobic Shielding, has been postulated in the synthesis of biocompatible contrast agents in vascular imaging. To improve the safety of these polyiodinated agents, interactions with protein hydrophobic sites in biomacromolecules should be kept as low as possible. In order to evaluate the level of interactions with proteins, we have selected the serine proteinase Elastase, in presence of Iobitridol (Xenetix), as a model. METHODS The complex between Iobitridol and Pancreatic Porcine Elastase was investigated by X-ray diffraction techniques, on saturated monocrystals, using the synchrotron radiation at 0.98A. RESULTS In contrast to Iohexol, which displays several interactions including one in the active site, Iobitridol is unable to interact directly with elastase. Only one partially occupied site is found in between two molecules of the crystal packing. CONCLUSIONS The validation of the "hydrophobic shielding" concept, which was at the origin of the design of the Iobitridol molecule, has been proven to be an essential feature in minimizing in vivo protein interactions.
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Affiliation(s)
- T Prangé
- Chimie Structurale Biomoleculaire (URA-1430 CNRS, Bobigny, France.
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Sterner NG, Nilsson H, Rosén U, Lilja B, Sundkvist G. Relationships among glomerular filtration rate, albuminuria, and autonomic nerve function in insulin-dependent and non-insulin-dependent diabetes mellitus. J Diabetes Complications 1997; 11:188-93. [PMID: 9174901 DOI: 10.1016/s1056-8727(96)00021-9] [Citation(s) in RCA: 4] [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: 02/04/2023]
Abstract
The associations among autonomic neuropathy, urinary albumin excretion, and glomerular filtration rate (GFR) measured with 51Cr-EDTA and iohexol clearance were studied in 41 patients with insulin-dependent diabetes mellitus (IDDM) and 15 patients with non-insulin-dependent diabetes mellitus (NIDDM). The study showed that increased urinary albumin excretion was more common in NIDDM than in IDDM. In contrast with IDDM, albuminuria in NIDDM was not related to GFR. Autonomic neuropathy was common in IDDM as well as in NIDDM, and also in patients without nephropathy, but was not connected with hyperfiltration. Low brake index, an ortostatic autonomic index, was associated with nephropathy in NIDDM. Iohexol, a non-ionic contrast medium, was found to be a useful alternative to 51Cr-EDTA for determination of GFR. Moreover, comparison between conventional four-sample plasma clearance and single-sample clearance showed a close correlation. Accordingly, assessment of GFR using a single plasma sample provides reliable results even at high GFR values.
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Affiliation(s)
- N G Sterner
- Department of Vascular and Renal Diseases, Malmö University Hospital, Sweden
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Abstract
This paper analyses the arterial enhancement produced by short intravenous boluses of iodinated contrast medium, with particular attention to the differences between various types of contrast media. A theoretical discussion is presented, followed by a small experimental study. The characteristics of the arterial time-attenuation curve are a function of the rate of contrast medium transit to the extracellular fluid (ECF), osmolality driven transit of water from the ECF into the plasma, direct effects on the heart and pulmonary circulation, the distribution of transit times in the cardiopulmonary circulation and recirculation. Theory predicts that while differences in peak arterial attenuation/peak height (PH) will be small, alterations in the areas under the time-attenuation curve (AUC) will reflect early-phase rate constants in the absence of major inotropic effects. The AUC should be higher for non-ionic than ionic media reflecting these lower rate constants. An experimental study on three healthy dogs confirmed these theoretical observations, with a slightly higher PH (6.5% higher) using a non-ionic medium but a substantially higher AUC (22% higher). (Differences significant at the 5% level, two-tailed paired t-test.) Our theoretical predictions and experimental findings suggest non-ionic media produce superior vascular enhancement, particularly shortly after injection. Possible clinical implications, particularly in dynamic enhanced computed tomography, are discussed.
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Affiliation(s)
- M J Blomley
- Department of Radiology, University of Chicago Hospitals, Illinois, USA
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Abstract
The aim of this study was to compare the in vitro effects of different classes of contrast media on both the blood coagulation system and on platelet function. Global tests (APTT, TT) and FpA and F1 + 2 generation measurements showed that ioxaglate (ionic dimer) presents the highest anticoagulant potential. The anticoagulant effects of nonionic agents were less marked, iodixanol (nonionic dimer) being significantly less anticoagulant than iohexol (nonionic monomer). Major platelet activation was observed with release of PF4, serotonin and PDGF-AB when iohexol was incubated for 1 min in whole blood. Iodixanol showed no effect over the same period, while moderate platelet activation was observed after 30 min. Under the same experimental conditions, ioxaglate had no effect on platelets even after incubation for 30 min, whereas activation was observed with 9 g/l saline control at this time. Prevention of thrombin formation and platelet activation is only achieved with ioxaglate, the ionic dimer. These findings may be clinically important in the thrombotic environment of radiological procedures and may explain the increased thrombotic risks observed with nonionic agents in interventional procedures.
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Affiliation(s)
- C Corot
- Andreas Gruentzig Cardiovascular Center, Emory University Hospital, Atlanta, USA
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Abstract
BACKGROUND Plasma clearance of iohexol (Omnipaque) is well suited for determination of glomerular filtration rate (GFR) during pregnancy. OBJECTIVE To settle guidelines for the use of iohexol clearance in diabetic pregnancy. STUDY DESIGN Prospective comparative. MATERIAL AND METHODS Iohexol (5 ml) was injected intravenously and plasma concentrations determined by high pressure liquid chromatography after 180-240 min in 44 diabetic pregnant women. RESULTS Iohexol clearance was normal in most cases of nephropathy or albuminuria. Iohexol clearance correlated negatively with blood pressure, S-Urate, and S-Creatinine. When S-Urate was < 232 mumol/l or S-Creatinine < 70 mumol/l, iohexol clearance was always normal (sensitivity = 1.0). When, in combination, S-Urate was > 345 mumol/l, and S-Creatinine > 70 mumol/l, iohexol clearance was always subnormal (sensitivity = specificity = Kappa index = 1.0). CONCLUSIONS In diabetic pregnancy, nephropathy or albuminuria cannot solely be used for selection of candidates for iohexol clearance determination. A S-Urate < 230 mumol/l (3.9 mg/dl) or S-Creatinine < 70 mumol/l (0.92 mg/dl) was reassuring for a normal GFR. We suggest iohexol clearance determinations in diabetic pregnancies when S-Urate is > 350 mumol/l (5.9 mg/dl) and/or S-Creatinine > 70 mumol/L.
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Affiliation(s)
- P Olofsson
- Department of Obstetrics and Gynecology, University of Lund, Sweden
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Fiirgaard B, Madsen HH, Svare U, Skjødt T, Zeeberg I. [Intracranial distribution of iohexol and iotrolan after cervical myelography]. Ugeskr Laeger 1995; 157:3901-4. [PMID: 7645065] [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: 01/26/2023]
Abstract
Twenty-eight consecutive patients undergoing cervical myelography were examined with either iohexol (14) or iotrolan (14). Just before the myelography a cranial CT was performed and control CT (3-5 slices) examinations were performed three, six, 24 and 48 hours afterwards. In all 28 patients CT showed intracranial contrast medium distribution after cervical myelography. The contrast medium distributed mainly in the subarachnoid space, first to the basal cisterns and the insular fissures, and to the 4th ventricle. The densities in the subarachnoid spaces were significantly higher after iotrolan than iohexol in the basal cisterns three and six hours after myelography, and in the 4th ventricle. The subcortical density was still increasing 48 hours after iotrolanmyelography while the subcortical density reached the maximum 24 hours after iohexolmyelography. Following cervical myelography the contrast media iohexol and iotrolan distribute intracranially and iotrolan seems to be eliminated more slowly than iohexol.
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Affiliation(s)
- B Fiirgaard
- Røntgenafdelingen og neurologisk afdeling, Vejle Sygehus
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