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Job KM, Roberts JK, Sherwin CM. Editorial: Methods and protocols in obstetric and pediatric pharmacology: 2022. Front Pharmacol 2023; 14:1205963. [PMID: 37251317 PMCID: PMC10213959 DOI: 10.3389/fphar.2023.1205963] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2023] [Accepted: 04/21/2023] [Indexed: 05/31/2023] Open
Affiliation(s)
- Kathleen M Job
- Division of Clinical Pharmacology, Department of Pediatrics, School of Medicine, The University of Utah, Salt Lake City, UT, United States
| | - Jessica K Roberts
- Simulations Plus, Inc., Cognigen Division, Lancaster, CA, United States
| | - Catherine M Sherwin
- Department of Pediatrics, Boonshoft School of Medicine, Wright State University, Dayton, OH, United States
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Job KM, Roberts JK, Enioutina EY, IIIamola SM, Kumar SS, Rashid J, Ward RM, Fukuda T, Sherbotie J, Sherwin CM. Treatment optimization of maintenance immunosuppressive agents in pediatric renal transplant recipients. Expert Opin Drug Metab Toxicol 2021; 17:747-765. [PMID: 34121566 PMCID: PMC10726690 DOI: 10.1080/17425255.2021.1943356] [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: 11/09/2020] [Accepted: 06/11/2021] [Indexed: 10/21/2022]
Abstract
Introduction: Graft survival in pediatric kidney transplant patients has increased significantly within the last three decades, correlating with the discovery and utilization of new immunosuppressants as well as improvements in patient care. Despite these developments in graft survival for patients, there is still improvement needed, particularly in long-term care in pediatric patients receiving grafts from deceased donor patients. Maintenance immunosuppressive therapies have narrow therapeutic indices and are associated with high inter-individual and intra-individual variability.Areas covered: In this review, we examine the impact of pharmacokinetic variability on renal transplantation and its association with age, genetic polymorphisms, drug-drug interactions, drug-disease interactions, renal insufficiency, route of administration, and branded versus generic drug formulation. Pharmacodynamics are outlined in terms of the mechanism of action for each immunosuppressant, potential adverse effects, and the utility of pharmacodynamic biomarkers.Expert opinion: Acquiring abetter quantitative understanding of immunosuppressant pharmacokinetics and pharmacodynamic components should help clinicians implement treatment regimens to maintain the balance between therapeutic efficacy and drug-related toxicity.
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Affiliation(s)
- Kathleen M Job
- Division of Clinical Pharmacology, Department of Pediatrics, University of Utah, Salt Lake City, UT, USA
| | - Jessica K Roberts
- Division of Clinical Pharmacology, Department of Pediatrics, University of Utah, Salt Lake City, UT, USA
| | - Elena Y Enioutina
- Division of Clinical Pharmacology, Department of Pediatrics, University of Utah, Salt Lake City, UT, USA
| | - Sílvia M IIIamola
- Department of Experimental and Clinical Pharmacology, College of Pharmacy, University of Minnesota, Minneapolis, MN, USA
| | - Shaun S Kumar
- Division of Clinical Pharmacology, Department of Pediatrics, University of Utah, Salt Lake City, UT, USA
| | - Jahidur Rashid
- Division of Clinical Pharmacology, Department of Pediatrics, University of Utah, Salt Lake City, UT, USA
| | - Robert M Ward
- Division of Clinical Pharmacology, Department of Pediatrics, University of Utah, Salt Lake City, UT, USA
- Department of Pediatrics, School of Medicine, University of Utah, Salt Lake City, UT, USA
| | - Tsuyoshi Fukuda
- Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH, USA
| | - Joseph Sherbotie
- Department of Pediatrics, School of Medicine, University of Utah, Salt Lake City, UT, USA
| | - Catherine M Sherwin
- Department of Experimental and Clinical Pharmacology, College of Pharmacy, University of Minnesota, Minneapolis, MN, USA
- Department of Pediatrics, Boonshoft School of Medicine, Dayton Children’s Hospital, Wright State University, Dayton, OH, USA
- Department of Pharmacotherapy, College of Pharmacy, University of Utah, Salt Lake City, UT, USA
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Panetta JC, Roberts JK, Huang J, Lin T, Daryani VM, Harstead KE, Patel YT, Onar-Thomas A, Campagne O, Ward DA, Broniscer A, Robinson G, Gajjar A, Stewart CF. Pharmacokinetic basis for dosing high-dose methotrexate in infants and young children with malignant brain tumours. Br J Clin Pharmacol 2020; 86:362-371. [PMID: 31657864 DOI: 10.1111/bcp.14160] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2019] [Revised: 10/03/2019] [Accepted: 10/15/2019] [Indexed: 01/17/2023] Open
Abstract
AIMS No population pharmacokinetic studies of high-dose methotrexate (HDMTX) have been conducted in infants with brain tumours, which are a vulnerable population. The aim of this study was to evaluate HDMTX disposition in these children to provide a rational basis for MTX dosing. METHODS Patients received 4 monthly courses of HDMTX (5 g/m2 or 2.5 g/m2 for infants aged ≤31 days) as a 24-h infusion. Serial samples were analysed for MTX by an enzyme immunoassay method. Pharmacokinetic parameters were estimated using nonlinear mixed effects population modelling. Demographics, concomitant medications and genetic polymorphisms were considered as pharmacokinetic covariates while MTX exposure and patient age were considered as covariates for Grade 3 and 4 toxicities. RESULTS The population pharmacokinetics of HDMTX were estimated in 178 patients (age range 0.02-4.7 years) in 648 courses. The population clearance and volume were 90 mL/min/m2 and 14.4 L/m2 , respectively. Significant covariates on body surface area adjusted MTX clearance included estimated glomerular filtration rate and co-treatment with dexamethasone or vancomycin. No significant association was observed between MTX toxicity and MTX exposure, patient age, leucovorin dosage or duration. MTX clearance in infants ≤31 days at enrolment was 44% lower than in older infants, but their incidence of toxicity was not higher since they also received a lower MTX dosage. CONCLUSIONS By aggressively following institutional clinical guidelines, HDMTX-related toxicities were low, and using covariates from the population pharmacokinetic model enabled the calculation of a rational dosage for this patient population for future clinical trials.
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Affiliation(s)
- John C Panetta
- Department of Pharmaceutical Sciences, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Jessica K Roberts
- Department of Pharmaceutical Sciences, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Jie Huang
- Department of Biostatistics, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Tong Lin
- Department of Biostatistics, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Vinay M Daryani
- Department of Pharmaceutical Sciences, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - K Elaine Harstead
- Department of Pharmaceutical Sciences, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Yogesh T Patel
- Department of Pharmaceutical Sciences, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Arzu Onar-Thomas
- Department of Biostatistics, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Olivia Campagne
- Department of Pharmaceutical Sciences, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Deborah A Ward
- Department of Pharmaceutical Sciences, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Alberto Broniscer
- Department of Oncology, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Giles Robinson
- Department of Oncology, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Amar Gajjar
- Department of Oncology, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Clinton F Stewart
- Department of Pharmaceutical Sciences, St. Jude Children's Research Hospital, Memphis, TN, USA
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Bauler M, Roberts JK, Wu CC, Fan B, Ferrara F, Yip BH, Diao S, Kim YI, Moore J, Zhou S, Wielgosz MM, Ryu B, Throm RE. Production of Lentiviral Vectors Using Suspension Cells Grown in Serum-free Media. Mol Ther Methods Clin Dev 2019; 17:58-68. [PMID: 31890741 PMCID: PMC6931067 DOI: 10.1016/j.omtm.2019.11.011] [Citation(s) in RCA: 51] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/31/2019] [Accepted: 11/15/2019] [Indexed: 02/09/2023]
Abstract
Lentiviral vectors are increasingly utilized in cell and gene therapy applications because they efficiently transduce target cells such as hematopoietic stem cells and T cells. Large-scale production of current Good Manufacturing Practices-grade lentiviral vectors is limited because of the adherent, serum-dependent nature of HEK293T cells used in the manufacturing process. To optimize large-scale clinical-grade lentiviral vector production, we developed an improved production scheme by adapting HEK293T cells to grow in suspension using commercially available and chemically defined serum-free media. Lentiviral vectors with titers equivalent to those of HEK293T cells were produced from SJ293TS cells using optimized transfection conditions that reduced the required amount of plasmid DNA by 50%. Furthermore, purification of SJ293TS-derived lentiviral vectors at 1 L yielded a recovery of 55% ± 14% (n = 138) of transducing units in the starting material, more than a 2-fold increase over historical yields from adherent HEK293T serum-dependent lentiviral vector preparations. SJ293TS cells were stable to produce lentiviral vectors over 4 months of continuous culture. SJ293TS-derived lentiviral vectors efficiently transduced primary hematopoietic stem cells and T cells from healthy donors. Overall, our SJ293TS cell line enables high-titer vector production in serum-free conditions while reducing the amount of input DNA required, resulting in a highly efficient manufacturing option.
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Affiliation(s)
- Matthew Bauler
- Vector Development and Production Laboratory, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Jessica K Roberts
- Vector Development and Production Laboratory, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Chang-Chih Wu
- Vector Development and Production Laboratory, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Baochang Fan
- Therapeutics Production and Quality, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Francesca Ferrara
- Vector Development and Production Laboratory, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Bon Ham Yip
- Vector Development and Production Laboratory, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Shiyong Diao
- Vector Development and Production Laboratory, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Young-In Kim
- Experimental Cell Therapeutics Lab, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Jennifer Moore
- Experimental Cell Therapeutics Lab, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Sheng Zhou
- Experimental Cell Therapeutics Lab, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Matthew M Wielgosz
- Vector Development and Production Laboratory, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Byoung Ryu
- Vector Development and Production Laboratory, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Robert E Throm
- Vector Development and Production Laboratory, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
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Roberts JK, Linakis MW, Liu X, Sherwin CMT, van den Anker JN. Evident bias in a paracetamol metabolite population pharmacokinetic model applied to an external dataset. Br J Clin Pharmacol 2018; 84:1628-1630. [PMID: 29667221 DOI: 10.1111/bcp.13588] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2017] [Revised: 02/26/2018] [Accepted: 03/05/2018] [Indexed: 11/28/2022] Open
Affiliation(s)
- Jessica K Roberts
- Division of Clinical Pharmacology, Department of Pediatrics, School of Medicine, University of Utah, Salt Lake City, Utah, USA
| | - Matthew W Linakis
- Division of Clinical Pharmacology, Department of Pediatrics, School of Medicine, University of Utah, Salt Lake City, Utah, USA.,Department of Pharmaceutics and Pharmaceutical Chemistry, College of Pharmacy, University of Utah, Salt Lake City, Utah, USA
| | - Xiaoxi Liu
- Division of Clinical Pharmacology, Department of Pediatrics, School of Medicine, University of Utah, Salt Lake City, Utah, USA
| | - Catherine M T Sherwin
- Division of Clinical Pharmacology, Department of Pediatrics, School of Medicine, University of Utah, Salt Lake City, Utah, USA.,Department of Pharmaceutics and Pharmaceutical Chemistry, College of Pharmacy, University of Utah, Salt Lake City, Utah, USA.,Department of Pharmacology and Toxicology, College of Pharmacy, University of Utah, Salt Lake City, Utah, USA
| | - John N van den Anker
- Division of Clinical Pharmacology, Children's National Health System, Washington, DC, USA.,Department of Pediatrics, Pharmacology and Physiology, School of Medicine and Health Sciences, George Washington University, Washington, DC, USA.,Intensive Care and Department of Pediatric Surgery, Erasmus Medical Center-Sophia Children's Hospital, Rotterdam, The Netherlands.,Division of Paediatric Pharmacology and Pharmacometrics, University Children's Hospital Basel, Basel, Switzerland
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6
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Ganguly S, Panetta JC, Roberts JK, Schuetz EG. Ketamine Pharmacokinetics and Pharmacodynamics Are Altered by P-Glycoprotein and Breast Cancer Resistance Protein Efflux Transporters in Mice. Drug Metab Dispos 2018; 46:1014-1022. [PMID: 29674491 DOI: 10.1124/dmd.117.078360] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Accepted: 04/16/2018] [Indexed: 01/16/2023] Open
Abstract
To understand the systemic impact of breast cancer resistance protein (Bcrp) and P-glycoprotein (Pgp) deletion, untargeted metabolomics was performed on cerebral spinal fluid (CSF) and plasma of wild-type (WT) and Pgp and Bcrp double-knockout (dKO) rats anesthetized with ketamine-xylazine. We unexpectedly found elevated ketamine levels in both CSF and plasma of dKO versus WT rats. Therefore, the effect of these transporters was investigated on the 1) oral and intraperitoneal serum pharmacokinetics (PK) of ketamine, using a liquid chromatography method (high-performance liquid chromatography with ultraviolet detection), and 2) the anesthetic effect of ketamine using a duration of loss-of-righting reflex (dLORR) test in WT, Bcrp knockout (KO), Pgp KO, and Pgp/Bcrp dKO mice. The PK data demonstrated a significantly increased oral bioavailability and serum exposure of ketamine in dKO > Pgp KO > Bcrp KO mice compared with WT mice. Intraperitoneal ketamine-induced dLORR was significantly longer in dKO > Pgp KO > Bcrp KO > WT mice compared with WT mice. Inhibition of Bcrp and Pgp in WT mice using the dual Pgp/Bcrp inhibitor elacridar increased the ketamine-induced dLORR compared with vehicle-treated mice. The ketamine intracellular concentration was significantly decreased in Madin-Darby canine kidney II BCRP/PGP cells compared with the parental cells. In total, these results demonstrate that ketamine appears to be a dual Pgp/Bcrp substrate whose PK and pharmacodynamics are affected by Pgp and Bcrp-mediated efflux.
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Affiliation(s)
- Samit Ganguly
- Department of Pharmaceutical Sciences, St. Jude Children's Research Hospital, Memphis, Tennessee, (S.G., J.C.P., J.K.R., E.G.S.); and Cancer and Developmental Biology Track, University of Tennessee Health Science Center, Memphis, Tennessee (S.G.)
| | - John C Panetta
- Department of Pharmaceutical Sciences, St. Jude Children's Research Hospital, Memphis, Tennessee, (S.G., J.C.P., J.K.R., E.G.S.); and Cancer and Developmental Biology Track, University of Tennessee Health Science Center, Memphis, Tennessee (S.G.)
| | - Jessica K Roberts
- Department of Pharmaceutical Sciences, St. Jude Children's Research Hospital, Memphis, Tennessee, (S.G., J.C.P., J.K.R., E.G.S.); and Cancer and Developmental Biology Track, University of Tennessee Health Science Center, Memphis, Tennessee (S.G.)
| | - Erin G Schuetz
- Department of Pharmaceutical Sciences, St. Jude Children's Research Hospital, Memphis, Tennessee, (S.G., J.C.P., J.K.R., E.G.S.); and Cancer and Developmental Biology Track, University of Tennessee Health Science Center, Memphis, Tennessee (S.G.)
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Linakis MW, Rower JE, Roberts JK, Miller EI, Wilkins DG, Sherwin CMT. Population pharmacokinetic model of transdermal nicotine delivered from a matrix-type patch. Br J Clin Pharmacol 2017; 83:2709-2717. [PMID: 28771779 DOI: 10.1111/bcp.13393] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2017] [Revised: 07/18/2017] [Accepted: 07/24/2017] [Indexed: 12/30/2022] Open
Abstract
AIMS Nicotine addiction is an issue faced by millions of individuals worldwide. As a result, nicotine replacement therapies, such as transdermal nicotine patches, have become widely distributed and used. While the pharmacokinetics of transdermal nicotine have been extensively described using noncompartmental methods, there are few data available describing the between-subject variability in transdermal nicotine pharmacokinetics. The aim of this investigation was to use population pharmacokinetic techniques to describe this variability, particularly as it pertains to the absorption of nicotine from the transdermal patch. METHODS A population pharmacokinetic parent-metabolite model was developed using plasma concentrations from 25 participants treated with transdermal nicotine. Covariates tested in this model included: body weight, body mass index, body surface area (calculated using the Mosteller equation) and sex. RESULTS Nicotine pharmacokinetics were best described with a one-compartment model with absorption based on a Weibull distribution and first-order elimination and a single compartment for the major metabolite, cotinine. Body weight was a significant covariate on apparent volume of distribution of nicotine (exponential scaling factor 1.42). After the inclusion of body weight in the model, no other covariates were significant. CONCLUSIONS This is the first population pharmacokinetic model to describe the absorption and disposition of transdermal nicotine and its metabolism to cotinine and the pharmacokinetic variability between individuals who were administered the patch.
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Affiliation(s)
- Matthew W Linakis
- Division of Clinical Pharmacology, Department of Pediatrics, University of Utah School of Medicine, Salt Lake City, Utah, USA.,Department of Pharmaceutics and Pharmaceutical Chemistry, University of Utah College of Pharmacy, Salt Lake City, Utah, USA
| | - Joseph E Rower
- Division of Clinical Pharmacology, Department of Pediatrics, University of Utah School of Medicine, Salt Lake City, Utah, USA
| | - Jessica K Roberts
- Division of Clinical Pharmacology, Department of Pediatrics, University of Utah School of Medicine, Salt Lake City, Utah, USA
| | - Eleanor I Miller
- Department of Pharmacology and Toxicology, Center for Human Toxicology, University of Utah, Salt Lake City, Utah, USA
| | - Diana G Wilkins
- Department of Pharmacology and Toxicology, Center for Human Toxicology, University of Utah, Salt Lake City, Utah, USA.,Division of Medical Laboratory Sciences, Department of Pathology, University of Utah School of Medicine, Salt Lake City, Utah, USA
| | - Catherine M T Sherwin
- Division of Clinical Pharmacology, Department of Pediatrics, University of Utah School of Medicine, Salt Lake City, Utah, USA.,Department of Pharmaceutics and Pharmaceutical Chemistry, University of Utah College of Pharmacy, Salt Lake City, Utah, USA
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Millisor VE, Roberts JK, Sun Y, Tang L, Daryani VM, Gregornik D, Cross SJ, Ward D, Pauley JL, Molinelli A, Brennan RC, Stewart CF. Derivation of new equations to estimate glomerular filtration rate in pediatric oncology patients. Pediatr Nephrol 2017; 32:1575-1584. [PMID: 28573537 PMCID: PMC5712286 DOI: 10.1007/s00467-017-3693-5] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/20/2016] [Revised: 04/27/2017] [Accepted: 04/28/2017] [Indexed: 11/25/2022]
Abstract
BACKGROUND AND OBJECTIVE Monitoring renal function is critical in treating pediatric patients, especially when dosing nephrotoxic agents. We evaluated the validity of the bedside Schwartz and Brandt equations in pediatric oncology patients and developed new equations for estimated glomerular filtration rate (eGFR) in these patients. METHODS A retrospective analysis was conducted comparing eGFR using the bedside Schwartz and Brandt equations to measured GFR (mGFR) from technetium-99m diethylenetriamine pentaacetic acid (99mTc-DTPA) between January 2007 and August 2013. An improved equation to estimate GFR was developed, simplified, and externally validated in a cohort of patients studied from September 2013 to June 2015. Carboplatin doses calculated from 99mTc-DTPA were compared with doses calculated by GFR-estimating equations. RESULTS Overall, the bedside Schwartz and Brandt equations did not precisely or accurately predict measured GFR (mGFR). Using a data subset, we developed a five-covariate equation, which included height, serum creatinine, age, blood urea nitrogen (BUN), and gender, and a simplified version (two-covariates), which contained height and serum creatinine. These equations were used to estimate GFR in 2036 studies, resulting in precise and accurate predictors of mGFR values. Equations were validated in an external cohort of 570 studies; both new equations were more accurate in calculating carboplatin doses than either the bedside Schwartz or Brandt equation. CONCLUSIONS Two new equations were developed to estimate GFR in pediatric oncology patients, both of which did a better job at estimating mGFR than published equations.
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Affiliation(s)
- Vanessa E Millisor
- Department of Pharmaceutical Sciences, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN, 38105, USA
| | - Jessica K Roberts
- Department of Pharmaceutical Sciences, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN, 38105, USA
| | - Yilun Sun
- Department of Biostatistics, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Li Tang
- Department of Biostatistics, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Vinay M Daryani
- Department of Pharmaceutical Sciences, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN, 38105, USA
| | - David Gregornik
- Department of Pharmaceutical Services, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Shane J Cross
- Department of Pharmaceutical Services, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Deborah Ward
- Department of Pharmaceutical Services, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Jennifer L Pauley
- Department of Pharmaceutical Services, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Alejandro Molinelli
- Department of Pharmaceutical Sciences, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN, 38105, USA
| | - Rachel C Brennan
- Department of Oncology, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Clinton F Stewart
- Department of Pharmaceutical Sciences, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN, 38105, USA.
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Barrette AM, Roberts JK, Chapin C, Egan EA, Segal MR, Oses-Prieto JA, Chand S, Burlingame AL, Ballard PL. Antiinflammatory Effects of Budesonide in Human Fetal Lung. Am J Respir Cell Mol Biol 2017; 55:623-632. [PMID: 27281349 DOI: 10.1165/rcmb.2016-0068oc] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Lung inflammation in premature infants contributes to the development of bronchopulmonary dysplasia (BPD), a chronic lung disease with long-term sequelae. Pilot studies administering budesonide suspended in surfactant have found reduced BPD without the apparent adverse effects that occur with systemic dexamethasone therapy. Our objective was to determine budesonide potency, stability, and antiinflammatory effects in human fetal lung. We cultured explants of second-trimester fetal lung with budesonide or dexamethasone and used microscopy, immunoassays, RNA sequencing, liquid chromatography/tandem mass spectrometry, and pulsating bubble surfactometry. Budesonide suppressed secreted chemokines IL-8 and CCL2 (MCP-1) within 4 hours, reaching a 90% decrease at 12 hours, which was fully reversed 72 hours after removal of the steroid. Half-maximal effects occurred at 0.04-0.05 nM, representing a fivefold greater potency than for dexamethasone. Budesonide significantly induced 3.6% and repressed 2.8% of 14,500 sequenced mRNAs by 1.6- to 95-fold, including 119 genes that contribute to the glucocorticoid inflammatory transcriptome; some are known targets of nuclear factor-κB. By global proteomics, 22 secreted inflammatory proteins were hormonally regulated. Two glucocorticoid-regulated genes of interest because of their association with lung disease are CHI3L1 and IL1RL1. Budesonide retained activity in the presence of surfactant and did not alter its surface properties. There was some formation of palmitate-budesonide in lung tissue but no detectable metabolism to inactive 16α-hydroxy prednisolone. We concluded that budesonide is a potent and stable antiinflammatory glucocorticoid in human fetal lung in vitro, supporting a beneficial antiinflammatory response to lung-targeted budesonide:surfactant treatment of infants for the prevention of BPD.
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Affiliation(s)
| | - Jessica K Roberts
- 2 Division of Clinical Pharmacology, Department of Pediatrics, University of Utah, Salt Lake City, Utah; and
| | | | - Edmund A Egan
- 3 Department of Pediatrics, University of Buffalo, Buffalo, New York
| | | | - Juan A Oses-Prieto
- 5 Chemistry & Pharmaceutical Chemistry, University of California, San Francisco, San Francisco, California
| | - Shreya Chand
- 5 Chemistry & Pharmaceutical Chemistry, University of California, San Francisco, San Francisco, California
| | - Alma L Burlingame
- 5 Chemistry & Pharmaceutical Chemistry, University of California, San Francisco, San Francisco, California
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Sun F, Gerrard GE, Roberts JK, Telford T, Namini S, Waller M, Flux G, Gill VM. Ten Year Experience of Radioiodine Dosimetry: is it Useful in the Management of Metastatic Differentiated Thyroid Cancer? Clin Oncol (R Coll Radiol) 2017; 29:310-315. [PMID: 28132755 DOI: 10.1016/j.clon.2017.01.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2016] [Accepted: 01/03/2017] [Indexed: 11/24/2022]
Abstract
AIMS When a fixed activity of radioiodine is given for differentiated thyroid cancer (DTC), absorbed doses of radioiodine can vary widely and are not usually measured. Leeds Cancer Centre has routinely used a form of lesion-specific dosimetry for radioiodine patients. This study investigated if the results of dosimetry influenced treatment decisions for patients with advanced DTC. MATERIALS AND METHODS Since 2005, patients with regionally advanced/metastatic DTC, who underwent radioiodine treatment together with dosimetry, were included in this study. Patients were excluded if their radioiodine post-treatment scan showed no abnormal uptake. Dosimetry was calculated using images taken 2, 3 and 7 days post-radioiodine. Regions of interest were drawn around lesions that required dosimetry and a time-dose activity curve was created. The total cumulative activity was equal to the area under the curve. Each patient's results were prospectively assessed by their oncologist regarding the usefulness of dosimetry in making management decisions. RESULTS Thirty patients were studied and underwent 102 admissions of radioiodine between them. Dosimetry was carried out during 83 of 102 admissions. An absorbed dose of >20 Gy was taken as significant from dosimetry calculations, following which further radioiodine was considered. In 80% of patients, dosimetry was found to be useful when making treatment decisions. Only on 1/19 admissions did dosimetry calculate a minimum dose above 20 Gy in patients who had a total of four or more admissions for radioiodine. Ten per cent (3/30) had a complete response to radioiodine, both biochemically and radiologically, with a median follow-up of 6.7 months. Thirty-three per cent had a partial response/stable disease to radioiodine. The remainder had progressive disease. The decision to discontinue radioiodine therapy was often based on dosimetry and thyroglobulin results. Dosimetry was very useful for patients with thyroglobulin antibodies. CONCLUSION Only 10% had a complete response. Therefore, a significant number of patients became refractory to radioiodine during a course of repeat admissions for treatment. Dosimetry (often together with thyroglobulin and anatomical scans) helped to identify these patients to avoid further futile radioiodine therapy.
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Affiliation(s)
- F Sun
- Leeds Cancer Centre, St James' University Hospital, Leeds, UK.
| | - G E Gerrard
- Leeds Cancer Centre, St James' University Hospital, Leeds, UK
| | - J K Roberts
- Leeds Cancer Centre, St James' University Hospital, Leeds, UK
| | - T Telford
- Medical Physics, St George's Hospital, London, UK
| | - S Namini
- Leeds Cancer Centre, St James' University Hospital, Leeds, UK
| | - M Waller
- Leeds Cancer Centre, St James' University Hospital, Leeds, UK
| | - G Flux
- Royal Marsden NHS Foundation Trust, Sutton, Surrey, UK
| | - V M Gill
- Leeds Cancer Centre, St James' University Hospital, Leeds, UK
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Skeen S, Sherr L, Tomlinson M, Croome N, Ghandi N, Roberts JK, Macedo A. Interventions to improve psychosocial well-being for children affected by HIV and AIDS: a systematic review. Vulnerable Child Youth Stud 2017; 12:91-116. [PMID: 29085436 PMCID: PMC5659734 DOI: 10.1080/17450128.2016.1276656] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
In addition to its contribution to child mortality, HIV/AIDS has a substantial impact on the psychosocial well-being of children across the globe and particularly in sub-Saharan Africa. We conducted a systematic review of the literature in order to identify studies that assess the effectiveness of interventions developed to improve the psychosocial well-being of children affected by HIV/AIDS, published between January 2008 and February 2016. Studies that were eligible for the review included male and/or female children under the age of 18 years of age, who had lost a parent to HIV/AIDS, were living with a parent with HIV/AIDS, or were vulnerable because of other social and economic factors and living in communities of high HIV and AIDS prevalence, including child and caregiver reports. Studies were included if they documented any intervention to improve the psychosocial well-being of children including psychological therapy, psychosocial support and/or care, medical interventions and social interventions, with psychological and/or social factors as outcomes. We identified 17 interventions to improve the psychosocial well-being of children affected by HIV/AIDS. Of these, 16 studies took place in eight different low and middle-income countries (LMIC), of which 6 were in southern and eastern Africa. One study took place in a high-income setting. Of the total, fifteen showed some significant benefits of the intervention, while two showed no difference to psychosocial outcomes as a result of the intervention. The content of interventions, dosage and length of follow up varied substantially between studies. There were few studies on children under seven years and several focused mostly on girls. Efforts to improve evaluation of interventions to improve the psychosocial well-being of children affected by HIV/AIDS have resulted in a number of new studies which met the inclusion criteria for the review. Most studies are specially designed research projects and not evaluations of existing services. We call for increased partnerships between policy-makers, practitioners and researchers in order to design evaluation studies and can feed into the growing evidence base.
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Affiliation(s)
- S Skeen
- Department of Psychology, Stellenbosch University, South Africa
- Department of Psychiatry and Mental Health, University of Cape Town, South Africa
| | - L Sherr
- Department of Infection and Population Health, University College London, United Kingdom
| | - M Tomlinson
- Department of Psychology, Stellenbosch University, South Africa
| | - N Croome
- Kings College London, United Kingdom
| | - N Ghandi
- Department of Infection and Population Health, University College London, United Kingdom
| | - J K Roberts
- Department of Infection and Population Health, University College London, United Kingdom
| | - A Macedo
- Department of Infection and Population Health, University College London, United Kingdom
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Hemmersbach-Miller M, Duronville J, Sethi S, Miller SE, Howell DN, Henshaw N, Alexander BD, Roberts JK. Hemorrhagic Herpes Simplex Virus Type 1 Nephritis: An Unusual Cause of Acute Allograft Dysfunction. Am J Transplant 2017; 17:287-291. [PMID: 27545820 DOI: 10.1111/ajt.14022] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2016] [Revised: 08/16/2016] [Accepted: 08/17/2016] [Indexed: 01/25/2023]
Abstract
Interstitial nephritis due to viruses is well-described after solid organ transplantation. Viruses implicated include cytomegalovirus; BK polyomavirus; Epstein-Barr virus; and, less commonly, adenovirus. We describe a rare case of hemorrhagic allograft nephritis due to herpes simplex virus type 1 at 10 days after living donor kidney transplantation. The patient had a favorable outcome with intravenous acyclovir and reduction of immunosuppression.
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Affiliation(s)
- M Hemmersbach-Miller
- Division of Infectious Diseases, Department of Medicine, Duke University Medical Center, Durham, NC
| | - J Duronville
- Division of Nephrology, Department of Medicine, Duke University Medical Center, Durham, NC
| | - S Sethi
- Division of Nephrology, Department of Medicine, Duke University Medical Center, Durham, NC
| | - S E Miller
- Department of Pathology, Duke University Medical Center, Durham, NC
| | - D N Howell
- Department of Pathology, Duke University Medical Center, Durham, NC
| | - N Henshaw
- Clinical Microbiology Laboratory, Duke University Medical Center, Durham, NC
| | - B D Alexander
- Division of Infectious Diseases, Department of Medicine, Duke University Medical Center, Durham, NC
| | - J K Roberts
- Division of Nephrology, Department of Medicine, Duke University Medical Center, Durham, NC
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Roberts JK, Stockmann C, Dahl MJ, Albertine KH, Egan E, Lin Z, Reilly CA, Ballard PL, Ballard RA, Ward RM. Pharmacokinetics of Budesonide Administered with Surfactant in Premature Lambs: Implications for Neonatal Clinical Trials. ACTA ACUST UNITED AC 2016; 11:53-61. [PMID: 26416605 DOI: 10.2174/1574884710666150929100210] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2015] [Revised: 09/17/2015] [Accepted: 09/28/2015] [Indexed: 11/22/2022]
Abstract
Bronchopulmonary dysplasia (BPD) is a chronic lung disease of premature human infants, which may persist through adulthood. Airway inflammation has been firmly established in the pathogenesis of BPD. Previous studies to reduce airway inflammation with high-dose dexamethasone demonstrated adverse neurological outcomes, despite lower incidences of BPD. Instillation of budesonide and surfactant can facilitate early extubation and reduce the incidence of BPD and death among very low birth weight infants. However, the pharmacokinetics of budesonide and its distribution into the lung and brain are unknown. Therefore, 5 premature lambs were administered 0.25 mg/kg budesonide, with surfactant as the vehicle. Plasma and tissue samples were taken from the lambs for measurement of budesonide, 16α- hydroxy prednisolone, and budesonide palmitate using LC/MS/MS. Peak plasma budesonide concentrations were inversely correlated with the oxygenation index (correlation coefficient of -0.75). plasma budesonide concentrations were extremely low (~10% of expected) for two lambs that had high oxygenation indices and were excluded from further analyses. For the remaining 5 premature lambs, a non-compartmental analysis demonstrated an AUCinf of 148.77 ± 28.16 h*μg/L, half-life of 4.76 ± 1.79 h, and Cmax of 46.17 ± 17.71 µg/L. Using population pharmacokinetic methods, a onecompartment model with exponential residual error and first-order absorption adequately described the data. The apparent clearance and apparent volume of distribution of budesonide were estimated at 6.29 L/h (1.99 L/h/kg) and 29.1 L (9.2 L/kg), respectively. Budesonide and budesonide palmitate, but not 16α-hydroxy prednisolone, were detected in lung tissue. In this study, budesonide and its metabolites were not detected in the brain, which suggests that intratracheal instillation suggests that after local pulmonary deposition, there is no evidence of budesonide accumulation in the central nervous system. Overall, these results show that peak plasma budesonide concentrations are inversely correlated with the oxygenation index and that lung-specific delivery of budesonide avoids accumulation of budesonide in the brain.
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Roberts MS, Selvo NS, Roberts JK, Daryani VM, Owens TS, Harstead KE, Gajjar A, Stewart CF. Determination of Methotrexate, 7-Hydroxymethotrexate, and 2,4-Diamino-N 10-methylpteroic Acid by LC-MS/MS in Plasma and Cerebrospinal Fluid and Application in a Pharmacokinetic Analysis of High-Dose Methotrexate. J LIQ CHROMATOGR R T 2016; 39:745-751. [PMID: 28824272 DOI: 10.1080/10826076.2016.1243558] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
A rapid and robust method for measuring methotrexate (MTX) and its two primary metabolites, 7-hydroxymethotrexate (7-OHMTX) and 2,4-diamino-N10-methylpteroic acid (DAMPA), was developed for use in pharmacokinetic studies of plasma and cerebrospinal fluid samples collected from infants with malignant brain tumors. Sample aliquots (100μL) were prepared for bioanalysis of MTX and metabolites using a Waters Oasis HLB microelution SPE plate. Chromatography was performed using a Phenomenex Synergi Polar-RP 4μ 75 × 2.0mm ID column heated to 40°C. A rapid gradient elution on a Shimadzu HPLC system was used, with mobile phase A consisting of water/formic acid (100/0.1 v/v) and mobile phase B consisting of acetonitrile/formic acid (100/0.1 v/v). Column eluent was analyzed using AB Sciex QTRAP 5500 instrumentation in electrospray ionization mode. The ion transitions (m/z) monitored were 455.2→308.1, 471.1→324.1, and 326.2→175.1 for MTX, 7-OHMTX, and DAMPA respectively. The method was linear over a range of 0.0022 - 5.5 μM for MTX, 0.0085 - 21 μM for 7-OHMTX, and 0.0031 - 7.7 μM for DAMPA. The method was applied to the analysis of serial plasma samples obtained from infants diagnosed with malignant brain tumors receiving high-dose MTX and results were compared to MTX concentrations from a TDx-FLx FPIA.
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Affiliation(s)
- Michael S Roberts
- Department of Pharmaceutical Sciences, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Nicholas S Selvo
- Department of Pharmaceutical Sciences, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Jessica K Roberts
- Department of Pharmaceutical Sciences, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Vinay M Daryani
- Department of Pharmaceutical Sciences, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Thandranese S Owens
- Department of Pharmaceutical Sciences, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - K Elaine Harstead
- Department of Pharmaceutical Sciences, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Amar Gajjar
- Department of Oncology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Clinton F Stewart
- Department of Pharmaceutical Sciences, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
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Roberts JK, Stockmann C, Ward RM, Beachy J, Baserga MC, Spigarelli MG, Sherwin CMT. Population Pharmacokinetics of Darbepoetin Alfa in Conjunction with Hypothermia for the Treatment of Neonatal Hypoxic-Ischemic Encephalopathy. Clin Pharmacokinet 2016; 54:1237-44. [PMID: 25989868 DOI: 10.1007/s40262-015-0286-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
AIM The aim of this study was to determine the population pharmacokinetics of darbepoetin alfa in hypothermic neonates with hypoxic-ischemic encephalopathy treated with hypothermia. METHODS Neonates ≥36 weeks gestation and <12 h postpartum with moderate to severe hypoxic-ischemic encephalopathy who were undergoing hypothermia treatment were recruited in this randomized, multicenter, investigational, new drug pharmacokinetic study. Two intravenous darbepoetin alfa treatment groups were evaluated: 2 and 10 µg/kg. Serum erythropoietin concentrations were measured using an enzyme-linked immunosorbent assay. Monolix 4.3.1 was used to estimate darbepoetin alfa clearance and volume of distribution. Covariates tested included: birthweight, gestational age, postnatal age, postmenstrual age, sex, Sarnat score, and study site. RESULTS Darbepoetin alfa pharmacokinetics were well described by a one-compartment model with exponential error. Clearance and the volume of distribution were scaled by birthweight (centered on the mean) a priori. Additionally, gestational age (also centered on the mean) significantly affected darbepoetin alfa clearance. Clearance and volume of distribution were estimated as 0.0465 L/h (95% confidence interval 0.0392-0.0537) and 1.58 L (95% confidence interval 1.29-1.87), respectively. CONCLUSIONS A one-compartment model successfully described the pharmacokinetics of darbepoetin alfa among hypothermic neonates treated for hypoxic-ischemic encephalopathy. Clearance decreased with increasing gestational age.
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Affiliation(s)
- Jessica K Roberts
- Division of Clinical Pharmacology, Department of Pediatrics, School of Medicine, University of Utah, 295 Chipeta Way, Salt Lake City, UT, 84108, USA
| | - Chris Stockmann
- Division of Clinical Pharmacology, Department of Pediatrics, School of Medicine, University of Utah, 295 Chipeta Way, Salt Lake City, UT, 84108, USA.,Department of Pharmacology and Toxicology, College of Pharmacy, University of Utah, 295 Chipeta Way, Salt Lake City, UT, 84108, USA
| | - Robert M Ward
- Division of Clinical Pharmacology, Department of Pediatrics, School of Medicine, University of Utah, 295 Chipeta Way, Salt Lake City, UT, 84108, USA.,Department of Pharmacology and Toxicology, College of Pharmacy, University of Utah, 295 Chipeta Way, Salt Lake City, UT, 84108, USA.,Division of Neonatology, Department of Pediatrics, School of Medicine, University of Utah, 295 Chipeta Way, Salt Lake City, UT, 84108, USA
| | - Joanna Beachy
- Division of Neonatology, Department of Pediatrics, School of Medicine, University of Utah, 295 Chipeta Way, Salt Lake City, UT, 84108, USA
| | - Mariana C Baserga
- Division of Neonatology, Department of Pediatrics, School of Medicine, University of Utah, 295 Chipeta Way, Salt Lake City, UT, 84108, USA
| | - Michael G Spigarelli
- Division of Clinical Pharmacology, Department of Pediatrics, School of Medicine, University of Utah, 295 Chipeta Way, Salt Lake City, UT, 84108, USA.,Department of Pharmacology and Toxicology, College of Pharmacy, University of Utah, 295 Chipeta Way, Salt Lake City, UT, 84108, USA
| | - Catherine M T Sherwin
- Division of Clinical Pharmacology, Department of Pediatrics, School of Medicine, University of Utah, 295 Chipeta Way, Salt Lake City, UT, 84108, USA.
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Roberts JK, Cook SF, Stockmann C, Rollins DE, Wilkins DG, Sherwin CMT. A Population Pharmacokinetic Analysis of Dextroamphetamine in the Plasma and Hair of Healthy Adults. Clin Drug Investig 2016; 35:633-43. [PMID: 26329917 DOI: 10.1007/s40261-015-0323-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
BACKGROUND AND OBJECTIVE Hair is an attractive matrix for amphetamine drug testing; however, little is known about the rate at which amphetamines are deposited into hair. Therefore, the purpose of this study was to determine the pharmacokinetics of oral dextroamphetamine in plasma and quantify the rate of deposition into hair in healthy adults using a linked population pharmacokinetic model. METHODS Healthy adults >18 years of age received dextroamphetamine 10 mg orally for 7 days. Plasma samples were collected over 48 h following the final dose, and hair was collected 5 weeks following the first dose. NONMEM 7.2 was used to estimate dextroamphetamine oral absorption rate constant, apparent clearance and volume of distribution of the plasma compartment, the plasma to hair incorporation rate constant, and the apparent volume of distribution in the hair compartment. RESULTS Dextroamphetamine pharmacokinetics were well-described by a one-compartment model with combined additive and proportional error for the plasma compartment, which was linked to a single compartment for the hair. Apparent clearance and volume of distribution in the plasma compartment were scaled by current body weight (centered on the mean). Melanin hair concentration was included as a significant covariate on the hair compartment. Absorption rate constant, clearance, and volume of distribution for the plasma compartment were estimated as 0.527 h(-1) (95% CI 0.467-0.586), 28.7 L/h (95% CI 27.1-30.3), and 377 L (95% CI 326-428), respectively. The incorporation rate constant from plasma to hair was 1.60e(-6) h(-1) (95% CI 1.06e(-6)-2.14e(-6)) and apparent volume of distribution in hair was 17.7 mg (95% CI 12.5-22.8). CONCLUSIONS A one-compartment plasma model linked to a single compartment for hair successfully described the pharmacokinetics of dextroamphetamine in healthy adults. The volume of distribution and clearance of dextroamphetamine increased with weight, and the volume of distribution of the hair compartment increased with greater melanin concentrations.
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Affiliation(s)
- Jessica K Roberts
- Division of Clinical Pharmacology, Department of Pediatrics, School of Medicine, University of Utah, 295 Chipeta Way, Salt Lake City, UT, 84108, USA
| | - Sarah F Cook
- Center for Human Toxicology, Department of Pharmacology and Toxicology, College of Pharmacy, University of Utah, Salt Lake City, UT, USA
| | - Chris Stockmann
- Division of Clinical Pharmacology, Department of Pediatrics, School of Medicine, University of Utah, 295 Chipeta Way, Salt Lake City, UT, 84108, USA.,Department of Pharmacology and Toxicology, College of Pharmacy, University of Utah, Salt Lake City, UT, USA
| | - Douglas E Rollins
- Center for Human Toxicology, Department of Pharmacology and Toxicology, College of Pharmacy, University of Utah, Salt Lake City, UT, USA
| | - Diana G Wilkins
- Center for Human Toxicology, Department of Pharmacology and Toxicology, College of Pharmacy, University of Utah, Salt Lake City, UT, USA.,Division of Medical Laboratory Sciences, Department of Pathology, School of Medicine, University of Utah, Salt Lake City, UT, USA
| | - Catherine M T Sherwin
- Division of Clinical Pharmacology, Department of Pediatrics, School of Medicine, University of Utah, 295 Chipeta Way, Salt Lake City, UT, 84108, USA.
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Constance JE, Balch AH, Stockmann C, Linakis MW, Korgenski EK, Roberts JK, Ward RM, Sherwin CMT, Spigarelli MG. A propensity-matched cohort study of vancomycin-associated nephrotoxicity in neonates. Arch Dis Child Fetal Neonatal Ed 2016; 101:F236-43. [PMID: 26400103 DOI: 10.1136/archdischild-2015-308459] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/22/2015] [Accepted: 09/01/2015] [Indexed: 12/12/2022]
Abstract
BACKGROUND The incidence of nephrotoxicity among vancomycin-treated neonates has been reported to range from 2% to 20%. These widely varying estimates have led to confusion and controversy regarding the safety of vancomycin among neonates. OBJECTIVE Evaluate the incidence of nephrotoxicity among neonates receiving vancomycin concomitantly with gentamicin. DESIGN Retrospective observational cohort study using propensity score matching to provide covariate balance between neonates who did or did not receive vancomycin based on factors known to be related to the development of renal dysfunction. SETTING Hospitals (n=22) throughout the Intermountain West, including a quaternary care children's hospital. PATIENTS Neonates ≤44 postmenstrual weeks (median gestational age: 31 (IQR 28-36) weeks) receiving intravenous gentamicin with or without exposure to vancomycin from January 2006 to December 2012. MAIN OUTCOME MEASURES Nephrotoxicity based on the modified Acute Kidney Injury Network criteria for acute kidney injury (AKI) or serum creatinine concentration ≥1.5 mg/dL persisting for ≥48 h. RESULTS The final cohort was comprised of 1066 neonates (533 receiving vancomycin and gentamicin vs 533 receiving gentamicin). In a propensity score-matched cohort that was well balanced across 16 covariates, AKI was not associated with vancomycin use (16 neonates receiving vancomycin vs 7 controls experienced AKI; OR 1.5; 95% CI 0.6 to 4.0). However, the presence of a patent ductus arteriosus, concomitant non-steroidal anti-inflammatory drug use, ≥1 positive blood cultures, low birth weight and higher severity of illness and risk of mortality scores were associated with an increased risk of nephrotoxicity. CONCLUSIONS These results corroborate several earlier reports and much anecdotal evidence describing the infrequent occurrence of nephrotoxicity in neonates receiving concomitant vancomycin and gentamicin.
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Affiliation(s)
| | - Alfred H Balch
- Department of Pediatrics, University of Utah, Salt Lake City, Utah, USA
| | - Chris Stockmann
- Department of Pediatrics, University of Utah, Salt Lake City, Utah, USA
| | - Matthew W Linakis
- Department of Pediatrics, University of Utah, Salt Lake City, Utah, USA
| | - E Kent Korgenski
- Pediatric Clinical Program, Intermountain Healthcare, Salt Lake City, Utah, USA
| | - Jessica K Roberts
- Department of Pediatrics, University of Utah, Salt Lake City, Utah, USA
| | - Robert M Ward
- Department of Pediatrics, University of Utah, Salt Lake City, Utah, USA
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Roberts JK, Birg AV, Lin T, Daryani VM, Panetta JC, Broniscer A, Robinson GW, Gajjar AJ, Stewart CF. Population Pharmacokinetics of Oral Topotecan in Infants and Very Young Children with Brain Tumors Demonstrates a Role of ABCG2 rs4148157 on the Absorption Rate Constant. ACTA ACUST UNITED AC 2016; 44:1116-22. [PMID: 27052877 DOI: 10.1124/dmd.115.068676] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2015] [Accepted: 04/05/2016] [Indexed: 01/21/2023]
Abstract
For infants and very young children with brain tumors, chemotherapy after surgical resection is the main treatment due to neurologic and neuroendocrine adverse effects from whole brain irradiation. Topotecan, an anticancer drug with antitumor activity against pediatric brain tumors, can be given intravenous or orally. However, high interpatient variability in oral drug bioavailability is common in children less than 3 years old. Therefore, this study aimed to determine the population pharmacokinetics of oral topotecan in infants and very young children, specifically evaluating the effects of age and ABCG2 and ABCB1 on the absorption rate constant (Ka), as well as other covariate effects on all pharmacokinetic parameters. A nonlinear mixed effects model was implemented in Monolix 4.3.2 (Lixoft, Orsay, France). A one-compartment model with first-order input and first-order elimination was found to adequately characterize topotecan lactone concentrations with population estimates as [mean (S.E.)]; Ka = 0.61 (0.11) h(-1), apparent volume of distribution (V/F) = 40.2 (7.0) l, and apparent clearance (CL/F) = 40.0 (2.9) l/h. After including the body surface area in the V/F and CL/F as a power model centered on the population median, the ABCG2 rs4148157 allele was found to play a significant role in the value of Ka Patients homozygous or heterozygous for G>A demonstrated a Ka value 2-fold higher than their GG counterparts, complemented with a 2-fold higher maximal concentration as well. These results demonstrate a possible role for the ABCG2 rs4148157 allele in the pharmacokinetics of oral topotecan in infants and very young children, and warrants further investigation.
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Affiliation(s)
- Jessica K Roberts
- Department of Pharmaceutical Sciences (J.K.R., A.V.B., V.M.D., J.C.P., C.F.S.), Department of Biostatistics (T.L.), and Department of Oncology (A.B., G.W.R., A.J.G.), St. Jude Children's Research Hospital, Memphis, Tennessee
| | - Anna V Birg
- Department of Pharmaceutical Sciences (J.K.R., A.V.B., V.M.D., J.C.P., C.F.S.), Department of Biostatistics (T.L.), and Department of Oncology (A.B., G.W.R., A.J.G.), St. Jude Children's Research Hospital, Memphis, Tennessee
| | - Tong Lin
- Department of Pharmaceutical Sciences (J.K.R., A.V.B., V.M.D., J.C.P., C.F.S.), Department of Biostatistics (T.L.), and Department of Oncology (A.B., G.W.R., A.J.G.), St. Jude Children's Research Hospital, Memphis, Tennessee
| | - Vinay M Daryani
- Department of Pharmaceutical Sciences (J.K.R., A.V.B., V.M.D., J.C.P., C.F.S.), Department of Biostatistics (T.L.), and Department of Oncology (A.B., G.W.R., A.J.G.), St. Jude Children's Research Hospital, Memphis, Tennessee
| | - John C Panetta
- Department of Pharmaceutical Sciences (J.K.R., A.V.B., V.M.D., J.C.P., C.F.S.), Department of Biostatistics (T.L.), and Department of Oncology (A.B., G.W.R., A.J.G.), St. Jude Children's Research Hospital, Memphis, Tennessee
| | - Alberto Broniscer
- Department of Pharmaceutical Sciences (J.K.R., A.V.B., V.M.D., J.C.P., C.F.S.), Department of Biostatistics (T.L.), and Department of Oncology (A.B., G.W.R., A.J.G.), St. Jude Children's Research Hospital, Memphis, Tennessee
| | - Giles W Robinson
- Department of Pharmaceutical Sciences (J.K.R., A.V.B., V.M.D., J.C.P., C.F.S.), Department of Biostatistics (T.L.), and Department of Oncology (A.B., G.W.R., A.J.G.), St. Jude Children's Research Hospital, Memphis, Tennessee
| | - Amar J Gajjar
- Department of Pharmaceutical Sciences (J.K.R., A.V.B., V.M.D., J.C.P., C.F.S.), Department of Biostatistics (T.L.), and Department of Oncology (A.B., G.W.R., A.J.G.), St. Jude Children's Research Hospital, Memphis, Tennessee
| | - Clinton F Stewart
- Department of Pharmaceutical Sciences (J.K.R., A.V.B., V.M.D., J.C.P., C.F.S.), Department of Biostatistics (T.L.), and Department of Oncology (A.B., G.W.R., A.J.G.), St. Jude Children's Research Hospital, Memphis, Tennessee
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Abstract
Administration of inhaled antimicrobials affords the ability to achieve targeted drug delivery into the respiratory tract, rapid entry into the systemic circulation, high bioavailability and minimal metabolism. These unique pharmacokinetic characteristics make inhaled antimicrobial delivery attractive for the treatment of many pulmonary diseases. This review examines recent pharmacokinetic trials with inhaled antibacterials, antivirals and antifungals, with an emphasis on the clinical implications of these studies. The majority of these studies revealed evidence of high antimicrobial concentrations in the airway with limited systemic exposure, thereby reducing the risk of toxicity. Sputum pharmacokinetics varied widely, which makes it challenging to interpret the result of sputum pharmacokinetic studies. Many no vel inhaled antimicrobial therapies are currently under investigation that will require detailed pharmacokinetic studies, including combination inhaled antimicrobial therapies, inhaled nanoparticle formulations of several antibacterials, inhaled non-antimicrobial adjuvants, inhaled antiviral recombinant protein therapies and semi-synthetic inhaled antifungal agents. Additionally, the development of new inhaled delivery devices, particularly for mechanically ventilated patients, will result in a pressing need for additional pharmacokinetic studies to identify optimal dosing regimens.
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Affiliation(s)
- Chris Stockmann
- Division of Clinical Pharmacology, Department of Paediatrics, University of Utah School of Medicine, 295 Chipeta Way, Salt Lake City, UT, 84108, USA
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20
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Cook SF, Roberts JK, Samiee-Zafarghandy S, Stockmann C, King AD, Deutsch N, Williams EF, Allegaert K, Wilkins DG, Sherwin CMT, van den Anker JN. Population Pharmacokinetics of Intravenous Paracetamol (Acetaminophen) in Preterm and Term Neonates: Model Development and External Evaluation. Clin Pharmacokinet 2016; 55:107-19. [PMID: 26201306 PMCID: PMC5564323 DOI: 10.1007/s40262-015-0301-3] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVES The aims of this study were to develop a population pharmacokinetic model for intravenous paracetamol in preterm and term neonates and to assess the generalizability of the model by testing its predictive performance in an external dataset. METHODS Nonlinear mixed-effects models were constructed from paracetamol concentration-time data in NONMEM 7.2. Potential covariates included body weight, gestational age, postnatal age, postmenstrual age, sex, race, total bilirubin, and estimated glomerular filtration rate. An external dataset was used to test the predictive performance of the model through calculation of bias, precision, and normalized prediction distribution errors. RESULTS The model-building dataset included 260 observations from 35 neonates with a mean gestational age of 33.6 weeks [standard deviation (SD) 6.6]. Data were well-described by a one-compartment model with first-order elimination. Weight predicted paracetamol clearance and volume of distribution, which were estimated as 0.348 L/h (5.5 % relative standard error; 30.8 % coefficient of variation) and 2.46 L (3.5 % relative standard error; 14.3 % coefficient of variation), respectively, at the mean subject weight of 2.30 kg. An external evaluation was performed on an independent dataset that included 436 observations from 60 neonates with a mean gestational age of 35.6 weeks (SD 4.3). The median prediction error was 10.1 % [95 % confidence interval (CI) 6.1-14.3] and the median absolute prediction error was 25.3 % (95 % CI 23.1-28.1). CONCLUSIONS Weight predicted intravenous paracetamol pharmacokinetics in neonates ranging from extreme preterm to full-term gestational status. External evaluation suggested that these findings should be generalizable to other similar patient populations.
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Affiliation(s)
- Sarah F Cook
- Center for Human Toxicology, Department of Pharmacology and Toxicology, University of Utah, Salt Lake City, UT, USA
| | - Jessica K Roberts
- Division of Clinical Pharmacology, Department of Pediatrics, University of Utah School of Medicine, 295 Chipeta Way, Salt Lake City, UT, 84108, USA
| | - Samira Samiee-Zafarghandy
- Division of Clinical Pharmacology, Children's National Health System, Washington, DC, USA
- Division of Neonatology, Department of Pediatrics, McMaster University, Hamilton, ON, Canada
| | - Chris Stockmann
- Division of Clinical Pharmacology, Department of Pediatrics, University of Utah School of Medicine, 295 Chipeta Way, Salt Lake City, UT, 84108, USA
- Department of Pharmacology and Toxicology, University of Utah, Salt Lake City, UT, USA
| | - Amber D King
- Center for Human Toxicology, Department of Pharmacology and Toxicology, University of Utah, Salt Lake City, UT, USA
| | - Nina Deutsch
- Division of Anesthesiology, Sedation, and Perioperative Medicine, Children's National Health System, Washington, DC, USA
| | - Elaine F Williams
- Division of Clinical Pharmacology, Children's National Health System, Washington, DC, USA
| | - Karel Allegaert
- Neonatal Intensive Care Unit, University Hospitals Leuven, Leuven, Belgium
- Department of Development and Regeneration, KU Leuven, Leuven, Belgium
| | - Diana G Wilkins
- Center for Human Toxicology, Department of Pharmacology and Toxicology, University of Utah, Salt Lake City, UT, USA
- Division of Medical Laboratory Sciences, Department of Pathology, University of Utah School of Medicine, Salt Lake City, UT, USA
| | - Catherine M T Sherwin
- Division of Clinical Pharmacology, Department of Pediatrics, University of Utah School of Medicine, 295 Chipeta Way, Salt Lake City, UT, 84108, USA.
| | - John N van den Anker
- Division of Clinical Pharmacology, Children's National Health System, Washington, DC, USA
- Departments of Pediatrics, Integrative Systems Biology, Pharmacology and Physiology, George Washington University School of Medicine and Health Sciences, Washington, DC, USA
- Intensive Care and Department of Pediatric Surgery, Erasmus Medical Center-Sophia Children's Hospital, Rotterdam, The Netherlands
- Department of Paediatric Pharmacology, University Children's Hospital Basel, Basel, Switzerland
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Stockmann C, Barrett JS, Roberts JK, Sherwin C. Use of Modeling and Simulation in the Design and Conduct of Pediatric Clinical Trials and the Optimization of Individualized Dosing Regimens. CPT Pharmacometrics Syst Pharmacol 2015; 4:630-40. [PMID: 26783499 PMCID: PMC4716585 DOI: 10.1002/psp4.12038] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/18/2015] [Revised: 09/01/2015] [Accepted: 09/07/2015] [Indexed: 12/11/2022]
Abstract
Mathematical models of drug action and disease progression can inform pediatric pharmacotherapy. In this tutorial, we explore the key issues that differentiate pediatric from adult pharmacokinetic (PK) / pharmacodynamic (PD) studies, describe methods to calculate the number of participants to be enrolled and the optimal times at which blood samples should be collected, and therapeutic drug monitoring methods for individualizing pharmacotherapy. The development of pediatric-specific drug dosing dashboards is also highlighted, with an emphasis on clinical-relevance and ease of use.
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Affiliation(s)
- C Stockmann
- Department of Pediatrics University of Utah School of Medicine Salt Lake City Utah USA
| | | | - J K Roberts
- Department of Pediatrics University of Utah School of Medicine Salt Lake City Utah USA
| | - Cmt Sherwin
- Department of Pediatrics University of Utah School of Medicine Salt Lake City Utah USA
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Baserga MC, Beachy JC, Roberts JK, Ward RM, DiGeronimo RJ, Walsh WF, Ohls RK, Anderson J, Mayock DE, Juul SE, Christensen RD, Loertscher MC, Stockmann C, Sherwin CM, Spigarelli MG, Yoder BA. Darbepoetin administration to neonates undergoing cooling for encephalopathy: a safety and pharmacokinetic trial. Pediatr Res 2015; 78:315-22. [PMID: 25996892 PMCID: PMC5564328 DOI: 10.1038/pr.2015.101] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/19/2014] [Accepted: 02/23/2015] [Indexed: 11/09/2022]
Abstract
BACKGROUND Despite therapeutic hypothermia, neonates with encephalopathy (NE) have high rates of death or disability. Darbepoetin alfa (Darbe) has comparable biological activity to erythropoietin, but has extended circulating half-life (t(1/2)). Our aim was to determine Darbe safety and pharmacokinetics as adjunctive therapy to hypothermia. STUDY DESIGN Thirty infants (n = 10/arm) ≥36 wk gestation undergoing therapeutic hypothermia for NE were randomized to receive placebo, Darbe low dose (2 μg/kg), or high dose (10 μg/kg) given intravenously within 12 h of birth (first dose/hypothermia condition) and at 7 d (second dose/normothermia condition). Adverse events were documented for 1 mo. Serum samples were obtained to characterize Darbe pharmacokinetics. RESULTS Adverse events (hypotension, altered liver and renal function, seizures, and death) were similar to placebo and historical controls. Following the first Darbe dose at 2 and 10 μg/kg, t(1/2) was 24 and 32 h, and the area under the curve (AUC(inf)) was 26,555 and 180,886 h*mU/ml*, respectively. In addition, clearance was not significantly different between the doses (0.05 and 0.04 l/h). At 7 d, t(1/2) was 26 and 35 h, and AUC(inf) was 10,790 and 56,233 h*mU/ml*, respectively (*P < 0.01). CONCLUSION Darbe combined with hypothermia has similar safety profile to placebo with pharmacokinetics sufficient for weekly administration.
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Affiliation(s)
- Mariana C. Baserga
- Division of Neonatology, Department of Pediatrics, University of Utah, Salt Lake City, Utah
| | - Joanna C. Beachy
- Division of Neonatology, Department of Pediatrics, University of Utah, Salt Lake City, Utah
| | - Jessica K. Roberts
- Division of Clinical Pharmacology, Department of Pediatrics, University of Utah, Salt Lake City, Utah
| | - Robert M. Ward
- Division of Neonatology, Department of Pediatrics, University of Utah, Salt Lake City, Utah,Division of Clinical Pharmacology, Department of Pediatrics, University of Utah, Salt Lake City, Utah
| | - Robert J. DiGeronimo
- Division of Neonatology, Department of Pediatrics, University of Utah, Salt Lake City, Utah
| | - William F. Walsh
- Division of Neonatology, Department of Pediatrics, Vanderbilt University, Nashville, Tennessee
| | - Robin K. Ohls
- Division of Neonatology, Department of Pediatrics, University of New Mexico, Albuquerque, New Mexico
| | - Jennifer Anderson
- Division of Neonatology, Department of Pediatrics, University of New Mexico, Albuquerque, New Mexico
| | - Dennis E. Mayock
- Division of Neonatology, Department of Pediatrics, University of Washington, Seattle, Washington
| | - Sandra E. Juul
- Division of Neonatology, Department of Pediatrics, University of Washington, Seattle, Washington
| | | | - Manndi C. Loertscher
- Division of Neonatology, Department of Pediatrics, University of Utah, Salt Lake City, Utah
| | - Chris Stockmann
- Division of Clinical Pharmacology, Department of Pediatrics, University of Utah, Salt Lake City, Utah
| | - Catherine M.T. Sherwin
- Division of Clinical Pharmacology, Department of Pediatrics, University of Utah, Salt Lake City, Utah
| | - Michael G. Spigarelli
- Division of Clinical Pharmacology, Department of Pediatrics, University of Utah, Salt Lake City, Utah
| | - Bradley A. Yoder
- Division of Neonatology, Department of Pediatrics, University of Utah, Salt Lake City, Utah
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Linakis MW, Roberts JK, Lala AC, Spigarelli MG, Medlicott NJ, Reith DM, Ward RM, Sherwin CMT. Challenges Associated with Route of Administration in Neonatal Drug Delivery. Clin Pharmacokinet 2015; 55:185-96. [DOI: 10.1007/s40262-015-0313-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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Stockmann C, Roberts JK, Yu T, Constance JE, Knibbe CAJ, Spigarelli MG, Sherwin CMT. Vancomycin pharmacokinetic models: informing the clinical management of drug-resistant bacterial infections. Expert Rev Anti Infect Ther 2015; 12:1371-88. [PMID: 25301231 DOI: 10.1586/14787210.2014.966081] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
This review aims to critically evaluate the pharmacokinetic literature describing the use of vancomycin in the treatment of methicillin-resistant Staphylococcus aureus (MRSA) infections. Guidelines recommend that trough concentrations be used to guide vancomycin dosing for the treatment of MRSA infections; however, numerous in vitro, animal model and clinical studies have demonstrated that the therapeutic effectiveness of vancomycin is best described by the area under the concentration versus time curve (AUC) divided by the minimum inhibitory concentration (MIC) of the infecting organism (AUC/MIC). Among patients with lower respiratory tract infections, an AUC/MIC ≥400 was associated with a superior clinical and bacteriological response. Similarly, patients with MRSA bacteremia who achieved an Etest AUC/MIC ≥320 within 48 h were 50% less likely to experience treatment failure. For other patient populations and different clinical syndromes (e.g., children, the elderly, patients with osteomyelitis, etc.), pharmacokinetic/pharmacodynamic studies and prospective clinical trials are needed to establish appropriate therapeutic targets.
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Affiliation(s)
- Chris Stockmann
- Department of Pediatrics, Division of Clinical Pharmacology, University of Utah School of Medicine, 295 Chipeta Way, Salt Lake City, Utah 84108, USA
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Stockmann C, Reilly CA, Fassl B, Gaedigk R, Nkoy F, Stone B, Roberts JK, Uchida DA, Leeder JS, Sherwin CMT, Spigarelli MG, Yost GS, Ward RM. Effect of CYP3A5*3 on asthma control among children treated with inhaled beclomethasone. J Allergy Clin Immunol 2015; 136:505-7. [PMID: 25825214 DOI: 10.1016/j.jaci.2015.02.009] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2014] [Revised: 02/10/2015] [Accepted: 02/10/2015] [Indexed: 11/28/2022]
Affiliation(s)
- Chris Stockmann
- Department of Pediatrics, University of Utah School of Medicine, Salt Lake City, Utah; Department of Pharmacology/Toxicology, University of Utah College of Pharmacy, Salt Lake City, Utah
| | - Christopher A Reilly
- Department of Pharmacology/Toxicology, University of Utah College of Pharmacy, Salt Lake City, Utah
| | - Bernhard Fassl
- Department of Pediatrics, University of Utah School of Medicine, Salt Lake City, Utah
| | - Roger Gaedigk
- Division of Clinical Pharmacology, Toxicology and Therapeutic Innovation, Children's Mercy Hospital, Kansas City, Mo
| | - Flory Nkoy
- Department of Pediatrics, University of Utah School of Medicine, Salt Lake City, Utah
| | - Bryan Stone
- Department of Pediatrics, University of Utah School of Medicine, Salt Lake City, Utah
| | - Jessica K Roberts
- Department of Pediatrics, University of Utah School of Medicine, Salt Lake City, Utah
| | - Derek A Uchida
- Department of Pediatrics, University of Utah School of Medicine, Salt Lake City, Utah
| | - J Steven Leeder
- Division of Clinical Pharmacology, Toxicology and Therapeutic Innovation, Children's Mercy Hospital, Kansas City, Mo
| | - Catherine M T Sherwin
- Department of Pediatrics, University of Utah School of Medicine, Salt Lake City, Utah
| | - Michael G Spigarelli
- Department of Pediatrics, University of Utah School of Medicine, Salt Lake City, Utah
| | - Garold S Yost
- Department of Pharmacology/Toxicology, University of Utah College of Pharmacy, Salt Lake City, Utah
| | - Robert M Ward
- Department of Pediatrics, University of Utah School of Medicine, Salt Lake City, Utah; Department of Pharmacology/Toxicology, University of Utah College of Pharmacy, Salt Lake City, Utah.
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Roberts JK, Stockmann C, Balch A, Yu T, Ward RM, Spigarelli MG, Sherwin CMT. Optimal design in pediatric pharmacokinetic and pharmacodynamic clinical studies. Paediatr Anaesth 2015; 25:222-30. [PMID: 25580772 DOI: 10.1111/pan.12575] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 10/23/2014] [Indexed: 11/30/2022]
Abstract
It is not trivial to conduct clinical trials with pediatric participants. Ethical, logistical, and financial considerations add to the complexity of pediatric studies. Optimal design theory allows investigators the opportunity to apply mathematical optimization algorithms to define how to structure their data collection to answer focused research questions. These techniques can be used to determine an optimal sample size, optimal sample times, and the number of samples required for pharmacokinetic and pharmacodynamic studies. The aim of this review is to demonstrate how to determine optimal sample size, optimal sample times, and the number of samples required from each patient by presenting specific examples using optimal design tools. Additionally, this review aims to discuss the relative usefulness of sparse vs rich data. This review is intended to educate the clinician, as well as the basic research scientist, whom plan on conducting a pharmacokinetic/pharmacodynamic clinical trial in pediatric patients.
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Affiliation(s)
- Jessica K Roberts
- Division of Clinical Pharmacology, Department of Pediatrics, School of Medicine, University of Utah, Salt Lake City, UT, USA
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Stockmann C, Roberts JK, Knackstedt ED, Spigarelli MG, Sherwin CM. Clinical pharmacokinetics and pharmacodynamics of ganciclovir and valganciclovir in children with cytomegalovirus infection. Expert Opin Drug Metab Toxicol 2014; 11:205-19. [PMID: 25428442 DOI: 10.1517/17425255.2015.988139] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
INTRODUCTION Among infants and immunocompromised children cytomegalovirus (CMV) is associated with significant morbidity and mortality. AREAS COVERED This review describes the clinical pharmacokinetics and pharmacodynamics of ganciclovir and valganciclovir for the treatment and prevention of CMV infection in children. EXPERT OPINION A 24-h ganciclovir area under the concentration versus time curve (AUC₀₋₂₄) of 40 - 60 μg h/ml decreased the risk of CMV infection for adults undergoing CMV prophylaxis. For adults undergoing treatment for active CMV disease, a target AUC₀₋₁₂ of 40 - 60 μg h/ml has been suggested. The applicability of these targets to children remains uncertain; however, with the most sophisticated dosing regimens developed to date only 21% of patients are predicted to reach these targets. Moving forward, identification of optimal pediatric ganciclovir and valganciclovir dosing regimens may involve the use of an externally validated pediatric population pharmacokinetic model for empirical dosing, an optimal sampling strategy for collecting a minimal number of blood samples for each patient and Bayesian updating of the dosing regimen based on an individual patient's pharmacokinetic profile.
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Affiliation(s)
- Chris Stockmann
- University of Utah School of Medicine, Division of Clinical Pharmacology, Department of Pediatrics , 295 Chipeta Way, Salt Lake City, UT 84108 , USA +1 801 587 7404 ; +1 801 585 9410 ;
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Roberts JK, Stockmann C, Constance JE, Stiers J, Spigarelli MG, Ward RM, Sherwin CMT. Pharmacokinetics and Pharmacodynamics of Antibacterials, Antifungals, and Antivirals Used Most Frequently in Neonates and Infants. Clin Pharmacokinet 2014; 53:581-610. [DOI: 10.1007/s40262-014-0147-0] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
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Abstract
Inhaled glucocorticoids are the first-line treatment for patients with persistent asthma. However, approximately thirty percent of patients exhibit glucocorticoid insensitivity, which may involve excess metabolic clearance of the glucocorticoids by CYP3A enzymes in the lung. CYP3A4, 3A5, and 3A7 enzymes metabolize glucocorticoids, which in turn induce CYP3A genes. However, the mechanism of CYP3A5 mRNA regulation by glucocorticoids in lung cells has not been determined. In hepatocytes, glucocorticoids bind to the glucocorticoid receptor (GR), which induces the expression of the constitutive androstane receptor or pregnane X receptor; both of which bind to the retinoid X receptor alpha, leading to the induction of CYP3A4, 3A5, and 3A7. There is also evidence to suggest a direct induction of CYP3A5 by GR activation in liver cells. In this study, these pathways were evaluated as the mechanism for CYP3A5 mRNA induction by glucocorticoids in freshly isolated primary tracheal epithelial, adenocarcinomic human alveolar basal epithelial (A549), immortalized bronchial epithelial (BEAS-2B), primary normal human bronchial/tracheal epithelial (NHBE), primary small airway epithelial (SAEC), and primary lobar epithelial lung cells. In A549 cells, beclomethasone 17-monopropionate ([M1]) induced CYP3A5 mRNA through the glucocorticoid receptor. CYP3A5 mRNA induction by five different glucocorticoids was attenuated by inhibiting the glucocorticoid receptor using ketoconazole, and for beclomethasone dipropionate, using siRNA-mediated knock-down of the glucocorticoid receptor. The constitutive androstane receptor was not expressed in lung cells. SAEC cells, a primary lung cell line, expressed CYP3A5, but CYP3A5 mRNA was not induced by glucocorticoid treatment despite evaluating a multitude of cell culture conditions. None of the other lung cells expressed CYP3A4, 3A5 or 3A7 mRNA. These studies demonstrate that CYP3A5 mRNA is induced by glucocorticoids in A549 cells via the glucocorticoid receptor, but that additional undefined regulatory processes exist in primary lung cells.
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Affiliation(s)
- Jessica K Roberts
- Department of Pharmacology and Toxicology, College of Pharmacy, University of Utah, Salt Lake City UT, 84112, USA
| | - Chad D Moore
- Department of Pharmacology and Toxicology, College of Pharmacy, University of Utah, Salt Lake City UT, 84112, USA
| | - Erin G Romero
- Department of Pharmacology and Toxicology, College of Pharmacy, University of Utah, Salt Lake City UT, 84112, USA
| | - Robert M Ward
- Department of Pediatrics, School of Medicine, University of Utah, Salt Lake City UT, 84108, USA
| | - Garold S Yost
- Department of Pharmacology and Toxicology, College of Pharmacy, University of Utah, Salt Lake City UT, 84112, USA
| | - Christopher A Reilly
- Department of Pharmacology and Toxicology, College of Pharmacy, University of Utah, Salt Lake City UT, 84112, USA
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Roberts JK, Moore CD, Ward RM, Yost GS, Reilly CA. Metabolism of beclomethasone dipropionate by cytochrome P450 3A enzymes. J Pharmacol Exp Ther 2013; 345:308-16. [PMID: 23512537 DOI: 10.1124/jpet.112.202556] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Inhaled glucocorticoids, such as beclomethasone dipropionate (BDP), are the mainstay treatment of asthma. However, ≈ 30% of patients exhibit little to no benefit from treatment. It has been postulated that glucocorticoid resistance, or insensitivity, is attributable to individual differences in glucocorticoid receptor-mediated processes. It is possible that variations in cytochrome P450 3A enzyme-mediated metabolism of BDP may contribute to this phenomenon. This hypothesis was explored by evaluating the contributions of CYP3A4, 3A5, 3A7, and esterase enzymes in the metabolism of BDP in vitro and relating metabolism to changes in CYP3A enzyme mRNA expression via the glucocorticoid receptor in lung and liver cells. CYP3A4 and CYP3A5 metabolized BDP via hydroxylation ([M4] and [M6]) and dehydrogenation ([M5]) at similar rates; CYP3A7 did not metabolize BDP. A new metabolite [M6], formed by the combined action of esterases and CYP3A4 hydroxylation, was also characterized. To validate the results observed using microsomes and recombinant enzymes, studies were also conducted using A549 lung and DPX2 liver cells. Both liver and lung cells produced esterase-dependent metabolites [M1-M3], with [M1] correlating with CYP3A5 mRNA induction in A549 cells. Liver cells produced both hydroxylated and dehydrogenated metabolites [M4, M5, and M6], but lung cells produced only the dehydrogenated metabolite [M5]. These studies show that CYP3A4 and CYP3A5 metabolize BDP to inactive metabolites and suggest that differences in the expression or function of these enzymes in the lung and/or liver could influence BDP disposition in humans.
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Affiliation(s)
- Jessica K Roberts
- Department of Pharmacology and Toxicology, College of Pharmacy, University of Utah, Salt Lake City, Utah, USA
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Moore CD, Roberts JK, Orton CR, Murai T, Fidler TP, Reilly CA, Ward RM, Yost GS. Metabolic pathways of inhaled glucocorticoids by the CYP3A enzymes. Drug Metab Dispos 2012; 41:379-89. [PMID: 23143891 DOI: 10.1124/dmd.112.046318] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Asthma is one of the most prevalent diseases in the world, for which the mainstay treatment has been inhaled glucocorticoids (GCs). Despite the widespread use of these drugs, approximately 30% of asthma sufferers exhibit some degree of steroid insensitivity or are refractory to inhaled GCs. One hypothesis to explain this phenomenon is interpatient variability in the clearance of these compounds. The objective of this research is to determine how metabolism of GCs by the CYP3A family of enzymes could affect their effectiveness in asthmatic patients. In this work, the metabolism of four frequently prescribed inhaled GCs, triamcinolone acetonide, flunisolide, budesonide, and fluticasone propionate, by the CYP3A family of enzymes was studied to identify differences in their rates of clearance and to identify their metabolites. Both interenzyme and interdrug variability in rates of metabolism and metabolic fate were observed. CYP3A4 was the most efficient metabolic catalyst for all the compounds, and CYP3A7 had the slowest rates. CYP3A5, which is particularly relevant to GC metabolism in the lungs, was also shown to efficiently metabolize triamcinolone acetonide, budesonide, and fluticasone propionate. In contrast, flunisolide was only metabolized via CYP3A4, with no significant turnover by CYP3A5 or CYP3A7. Common metabolites included 6β-hydroxylation and Δ(6)-dehydrogenation for triamcinolone acetonide, budesonide, and flunisolide. The structure of Δ(6)-flunisolide was unambiguously established by NMR analysis. Metabolism also occurred on the D-ring substituents, including the 21-carboxy metabolites for triamcinolone acetonide and flunisolide. The novel metabolite 21-nortriamcinolone acetonide was also identified by liquid chromatography-mass spectrometry and NMR analysis.
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Affiliation(s)
- Chad D Moore
- Department of Pharmacology and Toxicology, University of Utah, Salt Lake City, UT 84112, USA
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Thomas KC, Roberts JK, Deering-Rice CE, Romero EG, Dull RO, Lee J, Yost GS, Reilly CA. Contributions of TRPV1, endovanilloids, and endoplasmic reticulum stress in lung cell death in vitro and lung injury. Am J Physiol Lung Cell Mol Physiol 2012; 302:L111-9. [PMID: 21949157 PMCID: PMC3349369 DOI: 10.1152/ajplung.00231.2011] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [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: 07/11/2011] [Accepted: 09/21/2011] [Indexed: 12/31/2022] Open
Abstract
Endogenous agonists of transient receptor potential vanilloid-1 (TRPV1) (endovanilloids) are implicated as mediators of lung injury during inflammation. This study tested the hypothesis that endovanilloids produced following lipopolysaccharide (LPS) treatment activate TRPV1 and cause endoplasmic reticulum stress/GADD153 expression in lung cells, representing a mechanistic component of lung injury. The TRPV1 agonist nonivamide induced GADD153 expression and caused cytotoxicity in immortalized and primary human bronchial, bronchiolar/alveolar, and microvascular endothelial cells, proportional to TRPV1 mRNA expression. In CF-1 mice, Trpv1 mRNA was most abundant in the alveoli, and intratracheal nonivamide treatment promoted Gadd153 expression in the alveolar region. Treatment of CF-1 mice with LPS increased Gadd153 in the lung, lactate dehydrogenase (LDH) in bronchoalveolar lavage (BAL) fluid, and lung wet-to-dry weight ratio. Cotreating mice with LPS and the TRPV1 antagonist LJO-328 reduced Gadd153 induction and LDH in BAL but did not inhibit increases in lung wet-to-dry ratio. In Trpv1(-/-) mice treated with LPS, Gadd153 induction and LDH in BAL were reduced relative to wild-type mice, and the wet-to-dry weight ratios of lungs from both wild-type and Trpv1(-/-) mice decreased. Organic extracts of blood collected from LPS-treated mice were more cytotoxic to TRPV1-overexpressing cells compared with BEAS-2B cells and extracts from control mice, however, most pure endovanilloids did not produce cytotoxicity in a characteristic TRPV1-dependent manner. Collectively, these data indicate a role for TRPV1, and endogenous TRPV1 agonists, in ER stress and cytotoxicity in lung cells but demonstrate that ER stress and cytotoxicity are not essential for pulmonary edema.
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Affiliation(s)
- Karen C Thomas
- Department of Pharmacology and Toxicology, University of Utah, Salt Lake City, UT 84112, USA
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Deering-Rice CE, Johansen ME, Roberts JK, Thomas KC, Romero EG, Lee J, Yost GS, Veranth JM, Reilly CA. Transient receptor potential vanilloid-1 (TRPV1) is a mediator of lung toxicity for coal fly ash particulate material. Mol Pharmacol 2011; 81:411-9. [PMID: 22155782 DOI: 10.1124/mol.111.076067] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Environmental particulate matter (PM) pollutants adversely affect human health, but the molecular basis is poorly understood. The ion channel transient receptor potential vanilloid-1 (TRPV1) has been implicated as a sensor for environmental PM and a mediator of adverse events in the respiratory tract. The objectives of this study were to determine whether TRPV1 can distinguish chemically and physically unique PM that represents important sources of air pollution; to elucidate the molecular basis of TRPV1 activation by PM; and to ascertain the contributions of TRPV1 to human lung cell and mouse lung tissue responses exposed to an insoluble PM agonist, coal fly ash (CFA1). The major findings of this study are that TRPV1 is activated by some, but not all of the prototype PM materials evaluated, with rank-ordered responses of CFA1 > diesel exhaust PM > crystalline silica; TRP melastatin-8 is also robustly activated by CFA1, whereas other TRP channels expressed by airway sensory neurons and lung epithelial cells that may also be activated by CFA1, including TRPs ankyrin 1 (A1), canonical 4α (C4α), M2, V2, V3, and V4, were either slightly (TRPA1) or not activated by CFA1; activation of TRPV1 by CFA1 occurs via cell surface interactions between the solid components of CFA1 and specific amino acid residues of TRPV1 that are localized in the putative pore-loop region; and activation of TRPV1 by CFA1 is not exclusive in mouse lungs but represents a pathway by which CFA1 affects the expression of selected genes in lung epithelial cells and airway tissue.
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Maheshwari M, Roberts JK, DeSutter B, Duong K, Tingling J, Fawver JN, Schall HE, Kahle M, Murray IV. Hydralazine modifies Aβ fibril formation and prevents modification by lipids in vitro. Biochemistry 2010; 49:10371-80. [PMID: 21058733 PMCID: PMC3033120 DOI: 10.1021/bi101249p] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Lipid oxidative damage and amyloid β (Aβ) misfolding contribute to Alzheimer's disease (AD) pathology. Thus, the prevention of oxidative damage and Aβ misfolding are attractive targets for drug discovery. At present, no AD drugs approved by the Food and Drug Administration (FDA) prevent or halt disease progression. Hydralazine, a smooth muscle relaxant, is a potential drug candidate for AD drug therapy as it reduces Aβ production and prevents oxidative damage via its antioxidant hydrazide group. We evaluated the efficacy of hydralazine, and related hydrazides, in reducing (1) Aβ misfolding and (2) Aβ protein modification by the reactive lipid 4-hydroxy-2-nonenal (HNE) using transmission electron microscopy and Western blotting. While hydralazine did not prevent Aβ aggregation as measured using the protease protection assay, there were more oligomeric species observed by electron microscopy. Hydralazine prevented lipid modification of Aβ, and Aβ was used as a proxy for classes of proteins which either misfold or are modified by HNE. All of the other hydrazides prevented lipid modification of Aβ and also did not prevent Aβ aggregation. Surprisingly, a few of the compounds, carbazochrome and niclosamide, appeared to augment Aβ formation. Thus, hydrazides reduced lipid oxidative damage, and hydralazine additionally reduced Aβ misfolding. While hydralazine would require specific chemical modifications for use as an AD therapeutic itself (to improve blood brain barrier permeability, reduce vasoactive side effects, and optimization for amyloid inhibition), this study suggests its potential merit for further AD drug development.
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Affiliation(s)
| | | | | | | | | | | | | | | | - Ian V.J. Murray
- To whom correspondence should be addressed: Department of Neuroscience and Experimental Therapeutics, College of Medicine, Texas A&M Health Science Center, 142E Reynolds Medical Building, College Station Texas. 77843-1114. Telephone: (979) 458-4355. Fax: 979 845-0790.
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Affiliation(s)
- W R Wasef
- Tameside Acute Trust, Ashton-under-Lyne, UK
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Affiliation(s)
- R Keriakos
- Department of Obstetrics and Gynaecology, Tameside Hospital, Ashton-under-Lyne, UK
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Smith QW, Holcomb JD, Galvin J, Roberts JK. The effect of changes in the U.S. health care system on rehabilitation research: the results of a survey of rehabilitation health professionals. J Allied Health 2002; 30:207-14. [PMID: 11828581] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
Abstract
To obtain empirical data on the impact of changes in the health care system on rehabilitation research, physicians, psychologists, nurses, physical therapists, and occupational therapists involved in such research were surveyed to determine: 1) how the changes had affected their research productivity; 2) whether their scholarly activities (e.g., publications) had been affected; and 3) whether working in an academic vs non-academic institution made a difference. There were 438 usable responses (38% response rate) to the survey, which was sent to members of national organizations. Although the results somewhat supported suggestions that changes in the system had had a dampening effect on research, they were ambiguous, failing to clearly demonstrate a negative impact of managed care. More rigorous study is needed to enable firm conclusions and the formulation of actions to address factors that may influence rehabilitation research.
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Affiliation(s)
- Q W Smith
- Division of Allied Health Sciences, Department of Family and Community Medicine, Room 633E, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA
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Smith QW, Holcomb JD, Galvin J, DeJong G, DeLisa JA, Roberts JK. The effect of changes in the health care environment on rehabilitation research: a survey of rehabilitation physicians. Arch Phys Med Rehabil 2001; 82:1624-9. [PMID: 11689985 DOI: 10.1053/apmr.2001.26623] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
OBJECTIVE To assess what effect organizational, funding, and system changes in the health care environment may have on rehabilitation research. DESIGN National survey. SETTING Academic and clinical research programs. PARTICIPANTS A total of 138 physicians participated in the survey. INTERVENTION Mailed instrument requesting information on demographics, research activities, and indicators of change. MAIN OUTCOME MEASURES Percentage of respondents reporting specific perceptions on (1) how academic and research programs are affected by organizational changes, (2) availability of research funds, and (3) the overall impact that health care changes have on research; between-group comparisons on survey responses. RESULTS Usable responses were obtained from 138 physicians (response rate, 42.5%). Responding physicians reported workplace changes that included organizational restructuring (32.6%), affiliation with managed care plans (24%), and staff decreases (45.9%). Over half (54.8%) indicated that facility changes had detracted from their abilities to conduct research. A third (34.8%) reported declines in numbers of inpatient beds, and 89.6% reported decreased length of stay (LOS). Decreased LOS was cited as detracting from ongoing research by 36.6% and as discouraging new research by 33.3% of respondents. Although not reflected in measures of scholarly productivity, 53.6% reported having less time to devote to scholarship and 48.5% reported decreased professional activities. Over two thirds (67.4%) of responding physicians indicated that health care system changes had a negative impact on current research, and 54.5% indicated that such changes made it less likely that they would pursue new research. CONCLUSION Changes in the health care system have had a dampening effect on rehabilitation physicians' research pursuits.
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Affiliation(s)
- Q W Smith
- Department of Family and Community Medicine, Baylor College of Medicine, Houston, TX 77030, USA
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Perlak FJ, Oppenhuizen M, Gustafson K, Voth R, Sivasupramaniam S, Heering D, Carey B, Ihrig RA, Roberts JK. Development and commercial use of Bollgard cotton in the USA--early promises versus today's reality. Plant J 2001; 27:489-501. [PMID: 11576434 DOI: 10.1046/j.1365-313x.2001.01120.x] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Bollgard cotton is the trademark given to a number of varieties of cotton bio-engineered to produce an insecticidal protein from Bacillus thuringiensis (Bt). When produced by the modified cotton plants, this protein controls certain lepidopterous cotton insect pests. Commercially available since 1996, these cotton varieties are purchased under a license agreement in which the growers pay a fee and agree to abide by the terms, which include a 1-year license to use the technology and agreement to participate in an insect resistance management program. Today, Bollgard cotton is grown on more than one-third of all cotton acreage in the USA. This product has reduced cotton production costs and insecticide use by providing an effective alternative to chemical insecticides for the control of tobacco budworm, Heliothis virescens; cotton bollworm, Helicoverpa zea; and pink bollworm, Pectinophora gossypiella. The specificity and safety profile of the Bt protein produced in planta in cotton was maintained. It has retained its selectivity for lepidopterous insects and lacks the characteristics found in potential allergenic proteins. Fiber quality, the agronomic characteristics of the plant and seed composition remain unchanged. New cotton technology is being developed to provide improved insect control and a wider spectrum of activity. These future products could further reduce insecticide use in the production of cotton, while maintaining the high level of safety and reliability that has been demonstrated by five seasons of Bollgard cotton use.
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Affiliation(s)
- F J Perlak
- Monsanto Company, Chesterfield, MO 63198, USA.
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Abstract
Homocysteine is a metabolite of methionine that may be remethylated by enzymes requiring folate and cobalamin (vitamin B12) to again form methionine or catabolized by the pyridoxine (vitamin B6) dependent enzyme, cystathionine beta synthase (CBS) to form cysteine (fig. 1) [1]. Homocysteine exists as a combination of various free and protein bound forms, but the total amount is what is usually measured and may be reported as homocyst(e)ine [2]. The biological plausibility that elevated homocysteine might lead to vascular disease noted in 1969 by McCully [3]. He reported that a child with abnormal cobalamin metabolism and hyperhomocysteinemia had arterial lesions similar to those seen in children with severe hyperhomocysteinemia from CBS deficiency. These findings led to the idea that moderate elevations in homocysteine, even those still within the so-called normal range, might also lead to vascular pathology through a variety of mechanisms including atherosclerosis and thrombosis [4].
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Affiliation(s)
- R L Sacco
- Department of Neurology, Columbia Presbyterian Medical Center, New York, N.Y., USA
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Abstract
Stuttering is an uncommon presentation of acute stroke. Reported cases have often been associated with left sided cortical lesions, aphasia, and difficulties with other non-linguistic tests of rhythmic motor control. Three patients with subcortical lesions resulting in stuttering are discussed. In one patient the ability to perform time estimations with a computerised repetitive time estimation task was characterised. One patient had a pontine infarct with clinical evidence of cerebellar dysfunction. A second patient had a left basal ganglionic infarct and a disruption of timing estimation. A third patient had a left subcortical infarct and a mild aphasia. These findings expand the reported distribution of infarction that can result in acquired stuttering. Subcortical mechanisms of speech control and timing may contribute to the pathophysiology of acquired stuttering.
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Affiliation(s)
- A M Ciabarra
- New York-Presbyterian Medical Center, Neurological Institute, Department of Neurology, 710 West 168th Street, New York, New York 10032, USA
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Sau M, Sau AK, Roberts JK, Goldthorp W. Treatment of unruptured ectopic pregnancy with methotrexate. A UK experience. Acta Obstet Gynecol Scand 2000; 79:790-2. [PMID: 10993105] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
Affiliation(s)
- M Sau
- Department of Obstetrics & Gynaecology, Tameside General Hospital, Ashton-Under-Lyne, UK
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Chang WW, Huang L, Shen M, Webster C, Burlingame AL, Roberts JK. Patterns of protein synthesis and tolerance of anoxia in root tips of maize seedlings acclimated to a low-oxygen environment, and identification of proteins by mass spectrometry. Plant Physiol 2000; 122:295-318. [PMID: 10677424 PMCID: PMC58868 DOI: 10.1104/pp.122.2.295] [Citation(s) in RCA: 151] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/14/2023]
Abstract
Tolerance of anoxia in maize root tips is greatly improved when seedlings are pretreated with 2 to 4 h of hypoxia. We describe the patterns of protein synthesis during hypoxic acclimation and anoxia. We quantified the incorporation of [(35)S]methionine into total protein and 262 individual proteins under different oxygen tensions. Proteins synthesized most rapidly under normoxic conditions continued to account for most of the proteins synthesized during hypoxic acclimation, while the production of a very few proteins was selectively enhanced. When acclimated root tips were placed under anoxia, protein synthesis was depressed and no "new" proteins were detected. We present evidence that protein synthesis during acclimation, but not during subsequent anoxia, is crucial for acclimation. The complex and quantitative changes in protein synthesis during acclimation necessitate identification of large numbers of individual proteins. We show that mass spectrometry can be effectively used to identify plant proteins arrayed by two-dimensional gel electrophoresis. Of the 48 protein spots analyzed, 46 were identified by matching to the protein database. We describe the expression of proteins involved in a wide range of cellular functions, including previously reported anaerobic proteins, and discuss their possible roles in adaptation of plants to low-oxygen stress.
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Affiliation(s)
- W W Chang
- Department of Biochemistry, University of California, Riverside, California 92521, USA
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Abstract
The era of metabolic engineering has begun, but there is only limited knowledge about metabolic fluxes and how they are regulated in plants. Particular challenges are the non-linearities between enzyme abundances, metabolite concentrations and metabolic fluxes, and the existence of metabolic networks that provide multiple routes between many important metabolites. NMR offers the means to distinguish and quantitate the fluxes along different routes to key metabolites. NMR can therefore help us understand and resolve the apparent paradox of, on the one hand, great metabolic flexibility evident in the natural responses of plants and, on the other hand, the unpredictable changes in metabolism reported in genetically engineered plants.
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Affiliation(s)
- J K Roberts
- Dept of Biochemistry, University of California, Riverside, CA 92521, USA.
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Kim CY, Takahashi K, Nguyen TB, Roberts JK, Webster C. Identification of a nucleic acid binding domain in eukaryotic initiation factor eIFiso4G from wheat. J Biol Chem 1999; 274:10603-8. [PMID: 10187856 DOI: 10.1074/jbc.274.15.10603] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Higher plants have two complexes that bind the m7G-cap structure of mRNA and mediate interactions between mRNA and ribosomal subunits, designated eIF4F and eIFiso4F. Both complexes contain a small subunit that binds the 5'-cap structure of mRNA, and a large subunit, eIF4G or eIFiso4G, that binds other translation factors and RNA. Sequence-specific proteases were used to cleave native cap-binding complexes into structural domains, which were purified by affinity chromatography. We show here that eIFiso4G contains a central protease-resistant domain that binds specifically to nucleic acids. This domain spans Gln170 to Glu443 and includes four of the six homology blocks shared by eIFiso4G and eIF4G. A slightly shorter overlapping sequence, from Gly202 to Lys445, had no nucleic acid binding activity, indicating that the N-terminal end of the nucleic acid binding site lies within Gln170 to Arg201. The binding of the central domain and native eIFiso4F to RNA homopolymers and double- and single-stranded DNAs was studied. Both molecules had highest affinity for poly(G) and recognized single- and double-stranded sequences.
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Affiliation(s)
- C Y Kim
- Department of Biochemistry, University of California, Riverside, California 92521, USA
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Cooper RA, Cowan RA, Owens SE, Jeans SP, Roberts JK, Hillel PG, Slevin NJ, Allan E, Gupta NK, Collins CD. Does salivary gland scintigraphy predict response to pilocarpine in patients with post-radiotherapy xerostomia? Eur J Nucl Med 1999; 26:220-5. [PMID: 10079311 DOI: 10.1007/s002590050380] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
This study was undertaken to determine whether standard salivary gland scintigraphy may be used for the objective assessment of salivary gland sialogogues, in particular oral pilocarpine, in the treatment of post-radiotherapy xerostomia. Nine patients, with xerostomia following radiotherapy to the head and neck region underwent salivary gland scintigraphy with technetium-99m pertechnetate (40 MBq) both before and following 1 month of oral pilocarpine (5 mg tds). For each scan, the percentage uptake in the first 14 min, the peak uptake, time to peak uptake and the percentage of activity excreted following lemon juice stimulation were calculated. The results were correlated with the subjective response as assessed by questionnaire and visual analogue scale. We found no correlation between subjective response and any of the four scan parameters analysed. We could not identify any parameter that predicted those patients who would respond to pilocarpine. In addition, only one parameter, the percentage of activity excreted following stimulation, correlated with previous dose of radiotherapy to the gland. In conclusion, in this study salivary gland scintigraphy did not appear to correlate with or predict response to oral pilocarpine. However, future studies might consider performing salivary gland scintigraphy prior to radiotherapy as well as at differing time points following the commencement of pilocarpine.
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Affiliation(s)
- R A Cooper
- Department of Clinical Oncology, Christie Hospital, Manchester, UK
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Lee VH, Lee AB, Phillips EB, Roberts JK, Weitlauf HM. Spatio-temporal pattern for expression of galectin-3 in the murine utero-placental complex: evidence for differential regulation. Biol Reprod 1998; 58:1277-82. [PMID: 9603264 DOI: 10.1095/biolreprod58.5.1277] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
In mice, immunoreactive galectin-3 protein has previously been localized in uterine epithelial cells adjacent to implanting blastocysts as well as in the decidualized endometrium of implantation sites, uterine natural killer cells, and several types of placental trophoblast cells. Because galectin-3 is a soluble extracellular molecule, protein localization by immunohistochemical methods does not demonstrate its cellular origin. Therefore, the present study was undertaken to determine precisely which cell types in the utero-placental complex express galectin-3 mRNA. In situ hybridization results demonstrated that galectin-3 mRNA was expressed throughout the utero-placental complex in all cell types previously shown to contain immunoreactive protein, including uterine epithelium, decidualized endometrium, uterine natural killer cells, and placental trophoblasts. These results indicate that galectin-3 protein is not synthesized in a restricted cell type and translocated through the extracellular spaces to other tissue compartments. Furthermore, Northern blot analysis of total RNA prepared from separated fetal and maternal components of utero-placental complexes demonstrated different patterns of expression for galectin-3 mRNA in the uterus and placenta. Relative levels of galectin-3 mRNA peak at midgestation in the implantation site and during the second half of gestation remain elevated in the placenta but decline in the uterus. Separate mechanisms for regulating expression of galectin-3 on opposite sides of the feto-maternal interface are indicated.
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Affiliation(s)
- V H Lee
- Department of Cell Biology and Biochemistry, Texas Tech University Health Sciences Center, Lubbock 79430, USA.
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Roberts JK, Omarali I, Di Tullio MR, Sciacca RR, Sacco RL, Homma S. Valvular strands and cerebral ischemia. Effect of demographics and strand characteristics. Stroke 1997; 28:2185-8. [PMID: 9368562 DOI: 10.1161/01.str.28.11.2185] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
BACKGROUND AND PURPOSE Valvular strands, thin filamentous material attached to the mitral or aortic valve, are seen during transesophageal echocardiography and have been associated with stroke. Little is known about this association in different age, sex, and race-ethnic subgroups and the effect of various strand characteristics on this association. METHODS From patients referred for transesophageal echocardiography, 73 patients with recent ischemic stroke (68) or transient ischemic attack (5) were age matched to 73 stroke- and transient ischemic attack-free control subjects. The association between valvular strands and cerebral ischemia was evaluated for the overall group and demographic subgroups. The effect of strand location, length, number, and valve thickness was also determined. RESULTS An association between cerebral ischemia and valvular strands was observed (odds ratio [OR] = 4.4; 95% confidence interval [CI] = 2.0 to 9.6). The association was found for both men and women and among all three race-ethnic groups. The OR was greater in those who were younger (12.5 [95% CI = 2.4 to 64.5] for age < 60, 4.8 [95% CI = 1.3 to 18.2] for age 60 to 69, and 1.8 [95% CI = 0.5 to 6.4] for age > or = 70 years). Strands on both the mitral (OR = 3.5; 95% CI = 1.5 to 7.9) and aortic (OR = 3.7; 95% CI = 1.1 to 11.9) valve were associated with cerebral ischemia, whereas the number and length of strands were not. The effect of strands was independent of mitral or aortic valve thickness. CONCLUSIONS Valvular strands, whether mitral or aortic, are associated with ischemic stroke, especially among younger persons.
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Affiliation(s)
- J K Roberts
- Department of Neurology, Columbia-Presbyterian Medical Center, New York, NY 10032, USA.
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