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Dowell JA, Mason C. Candidate pathway association and genome-wide association approaches reveal alternative genetic architectures of carotenoid content in cultivated sunflower ( Helianthus annuus). Appl Plant Sci 2023; 11:e11558. [PMID: 38106540 PMCID: PMC10719882 DOI: 10.1002/aps3.11558] [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] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Revised: 05/10/2023] [Accepted: 05/19/2023] [Indexed: 12/19/2023]
Abstract
Premise The explosion of available genomic data poses significant opportunities and challenges for genome-wide association studies. Current approaches via linear mixed models (LMM) are straightforward but prevent flexible assumptions of an a priori genomic architecture, while Bayesian sparse LMMs (BSLMMs) allow this flexibility. Complex traits, such as specialized metabolites, are subject to various hierarchical effects, including gene regulation, enzyme efficiency, and the availability of reactants. Methods To identify alternative genetic architectures, we examined the genetic architecture underlying the carotenoid content of an association mapping panel of Helianthus annuus individuals using multiple BSLMM and LMM frameworks. Results The LMMs of genome-wide single-nucleotide polymorphisms (SNPs) identified a single transcription factor responsible for the observed variations in the carotenoid content; however, a BSLMM of the SNPs with the bottom 1% of effect sizes from the results of the LMM identified multiple biologically relevant quantitative trait loci (QTLs) for carotenoid content external to the known (annotated) carotenoid pathway. A candidate pathway analysis (CPA) suggested a β-carotene isomerase to be the enzyme with the highest impact on the observed carotenoid content within the carotenoid pathway. Discussion While traditional LMM approaches suggested a single unknown transcription factor associated with carotenoid content variation in sunflower petals, BSLMM proposed several QTLs with interpretable biological relevance to this trait. In addition, the CPA allowed for the dissection of the regulatory vs. biosynthetic genetic architectures underlying this metabolic trait.
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Affiliation(s)
- Jordan A. Dowell
- Department of Plant SciencesUniversity of CaliforniaDavisCalifornia95616USA
- Present address:
Department of Biological SciencesLouisiana State UniversityBaton RougeLouisiana70803USA
| | - Chase Mason
- Department of BiologyUniversity of Central FloridaOrlandoFlorida32816USA
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Thomas G, Rusman Q, Morrison WR, Magalhães DM, Dowell JA, Ngumbi E, Osei-Owusu J, Kansman J, Gaffke A, Pagadala Damodaram KJ, Kim SJ, Tabanca N. Deciphering Plant-Insect-Microorganism Signals for Sustainable Crop Production. Biomolecules 2023; 13:997. [PMID: 37371577 DOI: 10.3390/biom13060997] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Revised: 06/12/2023] [Accepted: 06/13/2023] [Indexed: 06/29/2023] Open
Abstract
Agricultural crop productivity relies on the application of chemical pesticides to reduce pest and pathogen damage. However, chemical pesticides also pose a range of ecological, environmental and economic penalties. This includes the development of pesticide resistance by insect pests and pathogens, rendering pesticides less effective. Alternative sustainable crop protection tools should therefore be considered. Semiochemicals are signalling molecules produced by organisms, including plants, microbes, and animals, which cause behavioural or developmental changes in receiving organisms. Manipulating semiochemicals could provide a more sustainable approach to the management of insect pests and pathogens across crops. Here, we review the role of semiochemicals in the interaction between plants, insects and microbes, including examples of how they have been applied to agricultural systems. We highlight future research priorities to be considered for semiochemicals to be credible alternatives to the application of chemical pesticides.
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Affiliation(s)
- Gareth Thomas
- Protecting Crops and the Environment, Rothamsted Research, Harpenden, AL5 2JQ, UK
| | - Quint Rusman
- Department of Systematic and Evolutionary Botany, University of Zürich, Zollikerstrasse 107, 8008 Zürich, Switzerland
| | - William R Morrison
- United States Department of Agriculture-Agricultural Research Service (USDA-ARS), Center for Grain and Animal Health Research, 1515 College Ave., Manhattan, KS 66502, USA
| | - Diego M Magalhães
- Luiz de Queiroz College of Agriculture, University of São Paulo, Piracicaba 13418-900, SP, Brazil
| | - Jordan A Dowell
- Department of Plant Sciences, University of California, Davis, One Shields Ave., Davis, CA 95616, USA
| | - Esther Ngumbi
- Department of Entomology, University of Illinois at Urbana Champaign, Urbana, IL 61801, USA
| | - Jonathan Osei-Owusu
- Department of Biological, Physical and Mathematical Sciences, University of Environment and Sustainable Development, Somanya EY0329-2478, Ghana
| | - Jessica Kansman
- Center for Chemical Ecology, Department of Entomology, The Pennsylvania State University, University Park, PA 16802, USA
| | - Alexander Gaffke
- United States Department of Agriculture-Agricultural Research Service (USDA-ARS), Center for Medical, Agricultural, and Veterinary Entomology, 6383 Mahan Dr., Tallahassee, FL 32308, USA
| | | | - Seong Jong Kim
- United States Department of Agriculture-Agricultural Research Service (USDA-ARS), Natural Products Utilization Research Unit, University, MS 38677, USA
| | - Nurhayat Tabanca
- United States Department of Agriculture-Agricultural Research Service (USDA-ARS), Subtropical Horticulture Research Station, 13601 Old Cutler Rd., Miami, FL 33158, USA
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Bahmani K, Robinson A, Majumder S, LaVardera A, Dowell JA, Goolsby EW, Mason CM. Broad diversity in monoterpene-sesquiterpene balance across wild sunflowers: Implications of leaf and floral volatiles for biotic interactions. Am J Bot 2022; 109:2051-2067. [PMID: 36317693 DOI: 10.1002/ajb2.16093] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/04/2022] [Accepted: 10/12/2022] [Indexed: 06/16/2023]
Abstract
PREMISE As plant lineages diversify across environmental gradients, species are predicted to encounter divergent biotic pressures. This study investigated the evolution of volatile secondary metabolism across species of Helianthus. METHODS Leaves and petals of 40 species of wild Helianthus were analyzed via gas chromatography-mass spectrometry to determine volatile secondary metabolite profiles. RESULTS Across all species, 500 compounds were identified; 40% were sesquiterpenes, 18% monoterpenes, 3% diterpenes, 4% fatty acid derivatives, and 35% other compounds such as phenolics and small organic molecules. Qualitatively, annuals and species from more arid western climates had leaf compositions with a higher proportion of total monoterpenes, while erect perennials and species from more mesic eastern habitats contained a higher proportion of total sesquiterpenes. Among species, mass-based leaf monoterpene and sesquiterpene abundance were identified as largely orthogonal axes of variation by principal component analysis. Profiles for leaves were not strongly correlated with those of petals. CONCLUSIONS Volatile metabolites were highly diverse among wild Helianthus, indicating the value of this genus as a model system and rich genetic resource. The independence of leaf and petal volatile profiles indicates a low level of phenotypic integration between vegetative and reproductive structures, implying vegetative defense and reproductive defense or pollinator attraction functions mediated by terpene profiles in these two organs can evolve without major trade-offs. The major biosynthetic pathways for the major terpenes in wild Helianthus are already well described, providing a road map to deeper inquiry into the drivers of this diversity.
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Affiliation(s)
- Keivan Bahmani
- Department of Biology, University of Central Florida, Orlando, FL, USA
| | | | - Sambadi Majumder
- Department of Biology, University of Central Florida, Orlando, FL, USA
| | | | - Jordan A Dowell
- Department of Plant Sciences, University of California, Davis, Davis, CA, USA
| | - Eric W Goolsby
- Department of Biology, University of Central Florida, Orlando, FL, USA
| | - Chase M Mason
- Department of Biology, University of Central Florida, Orlando, FL, USA
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Stahlhut KN, Dowell JA, Temme AA, Burke JM, Goolsby EW, Mason CM. Genetic control of arbuscular mycorrhizal colonization by Rhizophagus intraradices in Helianthus annuus (L.). Mycorrhiza 2021; 31:723-734. [PMID: 34480215 DOI: 10.1007/s00572-021-01050-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Accepted: 08/19/2021] [Indexed: 06/13/2023]
Abstract
Plant symbiosis with arbuscular mycorrhizal (AM) fungi provides many benefits, including increased nutrient uptake, drought tolerance, and belowground pathogen resistance. To develop a better understanding of the genetic architecture of mycorrhizal symbiosis, we conducted a genome-wide association study (GWAS) of this plant-fungal interaction in cultivated sunflower. A diversity panel of cultivated sunflower (Helianthus annuus L.) was phenotyped for root colonization under inoculation with the AM fungus Rhizophagus intraradices. Using a mixed linear model approach with a high-density genetic map, we identified genomic regions that are likely associated with R. intraradices colonization in sunflower. Additionally, we used a set of twelve diverse lines to assess the effect that inoculation with R. intraradices has on dried shoot biomass and macronutrient uptake. Colonization among lines in the mapping panel ranged from 0-70% and was not correlated with mycorrhizal growth response, shoot phosphorus response, or shoot potassium response among the Core 12 lines. Association mapping yielded three single-nucleotide polymorphisms (SNPs) that were significantly associated with R. intraradices colonization. This is the first study to use GWAS to identify genomic regions associated with AM colonization in an Asterid eudicot species. Three genes of interest identified from the regions containing these SNPs are likely related to plant defense.
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Affiliation(s)
| | - Jordan A Dowell
- Department of Biology, University of Central Florida, Orlando, FL, 32816, USA
| | - Andries A Temme
- Department of Plant Biology, University of Georgia, Athens, GA, 30602, USA
| | - John M Burke
- Department of Plant Biology, University of Georgia, Athens, GA, 30602, USA
| | - Eric W Goolsby
- Department of Biology, University of Central Florida, Orlando, FL, 32816, USA
| | - Chase M Mason
- Department of Biology, University of Central Florida, Orlando, FL, 32816, USA.
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De La Pascua DR, Smith-Winterscheidt C, Dowell JA, Goolsby EW, Mason CM. Evolutionary trade-offs in the chemical defense of floral and fruit tissues across genus Cornus. Am J Bot 2020; 107:1260-1273. [PMID: 32984956 DOI: 10.1002/ajb2.1540] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2019] [Accepted: 06/02/2020] [Indexed: 06/11/2023]
Abstract
PREMISE Defense investment in plant reproductive structures is relatively understudied compared to the defense of vegetative organs. Here the evolution of chemical defenses in reproductive structures is examined in light of the optimal defense, apparency, and resource availability hypotheses within the genus Cornus using a phylogenetic comparative approach in relation to phenology and native habitat environmental data. METHODS Individuals representing 25 Cornus species were tracked for reproductive phenology over a full growing season at the Arnold Arboretum of Harvard University. Floral, fruit, and leaf tissue was sampled to quantify defensive chemistry as well as fruit nutritional traits relevant to bird dispersal. Native habitat environmental characteristics were estimated using locality data from digitized herbarium records coupled with global soil and climate data sets. RESULTS The evolution of later flowering was correlated with increased floral tannins, and the evolution of later fruiting was correlated with increased total phenolics. Leaves were found to contain the highest tannin activity, while inflorescences contained the highest total flavonoids. Multiple aspects of fruit defensive chemistry were correlated with fruit nutritional traits. Floral and fruit defensive chemistry were evolutionarily correlated with aspects of native habitat temperature, precipitation, and soil characteristics. CONCLUSIONS Results provide tentative support for the apparency hypothesis with respect to both flower and fruit phenology, while relative concentrations of secondary metabolites across organs provide mixed support for the optimal defense hypothesis. The evolution of reproductive defense with native habitat provides, at best, mixed support for the resource availability hypothesis.
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Affiliation(s)
| | | | - Jordan A Dowell
- Department of Biology, University of Central Florida, Orlando, FL, 32816, USA
| | - Eric W Goolsby
- Department of Biology, University of Central Florida, Orlando, FL, 32816, USA
| | - Chase M Mason
- Department of Biology, University of Central Florida, Orlando, FL, 32816, USA
- Arnold Arboretum, Harvard University, Boston, MA, 02131, USA
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Dowell JA, Reynolds EC, Pliakas TP, Mandel JR, Burke JM, Donovan LA, Mason CM. Genome-Wide Association Mapping of Floral Traits in Cultivated Sunflower (Helianthus annuus). J Hered 2020; 110:275-286. [PMID: 30847479 DOI: 10.1093/jhered/esz013] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2018] [Accepted: 03/02/2019] [Indexed: 12/14/2022] Open
Abstract
Floral morphology and pigmentation are both charismatic and economically relevant traits associated with cultivated sunflower (Helianthus annuus L.). Recent work has linked floral morphology and pigmentation to pollinator efficiency and seed yield. Understanding the genetic architecture of such traits is essential for crop improvement, and gives insight into the role of genetic constraints in shaping floral diversity. A diversity panel of 288 sunflower genotypes was phenotyped for a variety of morphological, phenological, and color traits in both a greenhouse and a field setting. Association mapping was performed using 5788 SNP markers using a mixed linear model approach. Several dozen markers across 10 linkage groups were significantly associated with variation in morphological and color trait variation. Substantial trait plasticity was observed between greenhouse and field phenotyping, and associations differed between environments. Color traits mapped more strongly than morphology in both settings, with markers together explaining 16% of petal carotenoid content in the greenhouse, and 17% and 24% of variation in disc anthocyanin presence in the field and greenhouse, respectively. Morphological traits like disc size mapped more strongly in the field, with markers together explaining up to 19% of disc size variation. Loci identified here through association mapping within cultivated germplasm differ from those identified through biparental crosses between modern cultivated sunflower and either its wild progenitor or domesticated landraces. Several loci lie within genomic regions involved in domestication. Differences between phenotype expression under greenhouse and field conditions highlight the importance of plasticity in determining floral morphology and pigmentation.
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Affiliation(s)
- Jordan A Dowell
- Department of Biology, University of Central Florida, Orlando, FL
| | - Erin C Reynolds
- Department of Plant Biology, University of Georgia, Athens, GA
| | | | - Jennifer R Mandel
- Department of Biological Sciences, University of Memphis, Memphis, TN
| | - John M Burke
- Department of Plant Biology, University of Georgia, Athens, GA
| | - Lisa A Donovan
- Department of Plant Biology, University of Georgia, Athens, GA
| | - Chase M Mason
- Department of Biology, University of Central Florida, Orlando, FL.,Department of Plant Biology, University of Georgia, Athens, GA.,Arnold Arboretum, Harvard University, Boston, MA
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Dowell JA, Korth-Bradley J, Liu H, King SP, Berger MS. Pharmacokinetics of gemtuzumab ozogamicin, an antibody-targeted chemotherapy agent for the treatment of patients with acute myeloid leukemia in first relapse. J Clin Pharmacol 2001; 41:1206-14. [PMID: 11697753 DOI: 10.1177/00912700122012751] [Citation(s) in RCA: 94] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The purpose of this study was to characterize the pharmacokinetics of gemtuzumab ozogamicin (Mylotarg; Wyeth-Ayerst Laboratories, St. Davids, PA) in patients with acute myeloid leukemia (AML) in first relapse. Gemtuzumab ozogamicin is an antibody-chemotherapeutic conjugate characterized as antibody-targeted chemotherapy, consisting of an engineered human anti-CD33 antibody (hP67.6) linked to a potent cytotoxic agent, N-acetyl-gamma calicheamicin DMH. The pharmacokinetics of gemtuzumab ozogamicin was evaluated in 59 adult AML patients in first relapse, enrolled in a phase II study. Plasma was collected following each dose at specified times, and the pharmacokinetics was characterized by measures of hP67.6, total calicheamicin derivatives, and unconjugated calicheamicin derivatives. After administration of the first 9 mg/m2 dose of gemtuzumab ozogamicin, the pharmacokinetic parameters (mean +/- SD) of hP67.6 following the first dose were as follows: peak plasma concentration, 2.86 +/- 1.35 mg/L; AUC, 123 +/- 105 mg x h/L; t 1/2, 72.4 +/- 42.0 hours; and clearance, 0.265 +/- 0.229L/h. Increased concentrations were observed after the second dose and are believed to be due to a decrease in clearance by CD33-positive blast cells, a result of the reduced tumor burden following the first dose. The concentration profiles of calicheamicin followed the same time course as hP67.6, evidence that calicheamicin remained conjugated to the antibody and delivered to leukemic cells. No relationship was found between plasma concentration and response at the recommended dose. The pharmacokinetics of gemtuzumab ozogamicin has been characterized in AML patients receiving doses at the proposed therapeutic level.
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MESH Headings
- Acute Disease
- Adult
- Aged
- Aged, 80 and over
- Aminoglycosides
- Anti-Bacterial Agents/blood
- Anti-Bacterial Agents/chemistry
- Anti-Bacterial Agents/pharmacokinetics
- Antibiotics, Antineoplastic/blood
- Antibiotics, Antineoplastic/pharmacokinetics
- Antibodies, Monoclonal/blood
- Antibodies, Monoclonal/chemistry
- Antibodies, Monoclonal/pharmacokinetics
- Antibodies, Monoclonal, Humanized
- Antigens, CD/metabolism
- Antigens, Differentiation, Myelomonocytic/metabolism
- Antineoplastic Agents/therapeutic use
- Area Under Curve
- Cell Adhesion Molecules/metabolism
- Enediynes
- Female
- Gemtuzumab
- Humans
- Immunotoxins/blood
- Immunotoxins/chemistry
- Immunotoxins/pharmacokinetics
- Infusions, Intravenous
- Leukemia, Myeloid/drug therapy
- Leukemia, Myeloid/metabolism
- Leukemia, Myeloid/prevention & control
- Male
- Membrane Glycoproteins/metabolism
- Metabolic Clearance Rate
- Middle Aged
- Models, Biological
- Recurrence
- Sialic Acid Binding Ig-like Lectin 3
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Affiliation(s)
- J A Dowell
- Wyeth-Ayerst Research, Radnor, Pennsylvania, USA
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8
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Abstract
STUDY OBJECTIVE To determine the pharmacokinetic parameters of the components of gemtuzumab ozogamicin and to assess the possible influence of age and gender on the values. DESIGN Phase II, multicenter, open-label, nonrandomized, parallel study SETTING Hospitals and outpatient oncology clinics. PATIENTS Fifty-eight patients with acute myeloid leukemia in first relapse participated. Demographic data included 29 men and 29 women; 34 were younger than 60 years of age (mean age 53+/-16 yrs). INTERVENTION Patients received gemtuzumab ozogamicin as a single 2-hour infusion of 9 mg/m2. Serial plasma samples were collected over 10 days after the beginning of the infusion. MEASUREMENTS AND MAIN RESULTS Plasma concentrations of components of gemtuzumab ozogamicin (hP67.6 antibody, total and unconjugated calicheamicin derivatives) were measured by validated enzyme-linked immunosorbent assays. Pharmacokinetic parameters were determined by noncompartmental methods and comparisons between groups were made by analysis of variance. No significant differences were seen between men and women or between those over 60 and those less than 60 years of age in maximum concentration, time to maximum concentration, area under the curve, clearance, or volume of distribution for components of gemtuzumab ozogamicin. CONCLUSION No differences occur in the pharmacokinetics of the components of gemtuzumab ozogamicin (hP67.6 or calicheamicin) based on gender or age.
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Affiliation(s)
- J M Korth-Bradley
- Department of Clinical Pharmacokinetics, Wyeth-Ayerst Research, Philadelphia, Pennsylvania 19101, USA
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9
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Dowell JA, Korth-Bradley J, Milisci M, Tantillo K, Amorusi P, Tse S. Evaluating possible pharmacokinetic interactions between tobramycin, piperacillin, and a combination of piperacillin and tazobactam in patients with various degrees of renal impairment. J Clin Pharmacol 2001; 41:979-86. [PMID: 11549103 DOI: 10.1177/00912700122010960] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
A study was performed to further investigate the apparent instability of tobramycin when coadministered with piperacillin/tazobactam in subjects with renal impairment. Twenty-six otherwise healthy volunteers between 23 and 74 years of age were studied. Eight subjects had moderate renal impairment, 10 had mild renal impairment, and 8 had normal renal function. Each subject received single doses of piperacillin/tazobactam and tobramycin alone as well as combined doses in a randomized, three-way crossover design. The subjects with normal renal function also received combined doses of piperacillin and tobramycin. Considerable care was taken to protect against in vitro inactivation of plasma and urine samples after collection. No systematic changes in pharmacokinetic parameters were observed. It is concluded that piperacillin, either alone or with tazobactam, did not change the pharmacokinetics of tobramycin in subjects with renal impairment. The apparent in vivo inactivation of tobramycin in the presence of piperacillin or piperacillin/tazobactam reported by others may be an artifact of ex vivo inactivation.
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Affiliation(s)
- J A Dowell
- Clinical Pharmacokinetics, Wyeth-Ayerst Research, Radnor, Pennsylvania, USA
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10
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Dowell JA, Sancho AR, Anand D, Wolf W. Noninvasive measurements for studying the tumoral pharmacokinetics of platinum anticancer drugs in solid tumors. Adv Drug Deliv Rev 2000; 41:111-26. [PMID: 10699308 DOI: 10.1016/s0169-409x(99)00059-9] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
An effective methodology to determine the amount of cisplatin or carboplatin at the solid tumor site in a noninvasive manner may enable clinicians to design drug regimens based on an individual's in situ pharmacokinetics. Such noninvasive methods may allow optimization of an individual's drug exposure at the target site, as well as provide a screening measure to determine individual efficacy based on exposure to these platinated drugs. 195mPt appears to be the radionuclide of platinum most suitable for radiolabeling cisplatin or carboplatin, and an analysis is presented of the methods available for preparing such radiolabeled drugs. The use of this methodology is illustrated in detail in studies in animals, as well as some preliminary studies in humans. The animals used were Sprague Dawley rats bearing the Walker 256 carcinoma, and drug biodistribution was studied following administration of cisplatin or carboplatin radiolabeled with 195mPt. This radionuclide permitted noninvasive imaging of the drug and its metabolites at the tumor site and at selected organs. The results obtained show an ability to estimate the amount of platinated drug species in the tumor environment using a noninvasive methodology. Various compartmental models were tested, some of which could be validated experimentally. This noninvasive method is able to provide individual estimates of the active component of the drug at the target site, and is therefore a method that can be implemented in human studies.
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Affiliation(s)
- J A Dowell
- Wyeth Ayerst Research, Radnor, PA 19087, USA
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11
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Dowell JA, Hussain A, Devane J, Young D. Artificial neural networks applied to the in vitro-in vivo correlation of an extended-release formulation: initial trials and experience. J Pharm Sci 1999; 88:154-60. [PMID: 9874718 DOI: 10.1021/js970148p] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Artificial neural networks applied to in vitro-in vivo correlations (ANN-IVIVC) have the potential to be a reliable predictive tool that overcomes some of the difficulties associated with classical regression methods, principally, that of providing an a priori specification of the regression equation structure. A number of unique ANN configurations are presented, that have been evaluated for their ability to determine an IVIVC from different formulations of the same product. Configuration variables included a combination of architectural structures, learning algorithms, and input-output association structures. The initial training set consisted of two formulations and included the dissolution from each of the six cells in the dissolution bath as inputs, with associated outputs consisting of 1512 pharmacokinetic time points from nine patients enrolled in a crossover study. A third formulation IVIVC data set was used for predictive validation. Using these data, a total of 29 ANN configurations were evaluated. The ANN structures included the traditional feed forward, recurrent, jump connections, and general regression neural networks, with input-output association types consisting of the direct mapping of the dissolution profiles to the pharmacokinetic observations, mapping the individual dissolution points to the individual observations, and using a "memorative" input-output association. The ANNs were evaluated on the basis of their predictive performance, which was excellent for some of these ANN models. This work provides a basic foundation for ANN-IVIVC modeling and is the basis for continued modeling with other desirable inputs, such as formulation variables and subject demographics.
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Affiliation(s)
- J A Dowell
- In Vitro-In Vivo Relationship Cooperative Working Group, Pharmacokinetics-Biopharmaceutics Laboratory, Department of Pharmaceutical Sciences, University of Maryland at Baltimore, Baltimore, Maryland 21201, USA
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12
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Abstract
PURPOSE Anesthetics can alter the biodistribution profile of drugs and, consequently, the regional pharmacokinetics of antineoplastic drugs at the tumor site. The effect of coadministered anesthetics on the biodistribution profile of carboplatin was studied in rats. METHODS Female Wistar rats were used to compare the effects of ketamine/xylazine, thiopental and pentobarbital on the biodistribution of 30 mg/kg radiolabelled 195mPt-carboplatin administered intravenously, with conscious rats as the control group. Blood and urine samples were collected between 5 and 120 min. RESULTS The percentage values of the injected dose of platinum per ml (%ID/ml) in plasma at the final time-point were respectively, 0.557%, 0.156%, 0.115% and 0.086%, in pentobarbital-, ketamine/xylazine- and thiopental-injected rats, and in conscious animals. Following the same sequence of groups, the %ID/ml values of platinum in the cumulative urine were 0.001%, 0.619%, 0.184% and 0.118%, respectively. Urine output varied from very little in the pentobarbital group, to several milliliters in the other groups. CONCLUSIONS There was an increase of almost 100-fold in total platinum uptake in the kidneys, cerebrum and cerebellum of rats receiving pentobarbital over the uptake in the control rats, whereas the biodistribution profile of the thiopental group had the least variance. These results demonstrate the importance of anesthetic selection in animal pharmacokinetic studies, as it influences the biodistribution and pharmacokinetic profile of the drug being studied.
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Affiliation(s)
- A R Sancho
- Department of Pharmaceutical Sciences, University of Southern California, Los Angeles, USA.
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13
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Young D, Dowell JA, Piscitelli DA, Devane J. Validation of in vitro-in vivo correlation models. Adv Exp Med Biol 1997; 423:87-91. [PMID: 9269485 DOI: 10.1007/978-1-4684-6036-0_7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Affiliation(s)
- D Young
- Pharmacokinetics-Biopharmaceutics lab, School of Pharmacy, University of Maryland, Baltimore 21201, USA
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14
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Dowell JA, Hussain AS, Stark P, Devane J, Young D. Development of in vitro-in vivo correlations using various artificial neural network configurations. Adv Exp Med Biol 1997; 423:225-39. [PMID: 9269500 DOI: 10.1007/978-1-4684-6036-0_22] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Affiliation(s)
- J A Dowell
- University of Maryland at Baltimore, USA
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