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Mileo PGM, Krauter CM, Sanders JM, Browning AR, Halls MD. Molecular-Scale Exploration of Mechanical Properties and Interactions of Poly(lactic acid) with Cellulose and Chitin. ACS Omega 2023; 8:42417-42428. [PMID: 38024724 PMCID: PMC10652380 DOI: 10.1021/acsomega.3c04880] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/07/2023] [Revised: 10/10/2023] [Accepted: 10/13/2023] [Indexed: 12/01/2023]
Abstract
Poly(lactic acid) (PLA), one of the pillars of the current overarching displacement trend switching from fossil- to natural-based polymers, is often used in association with polysaccharides to increase its mechanical properties. However, the use of PLA/polysaccharide composites is greatly hampered by their poor miscibility, whose underlying nature is still vastly unexplored. This work aims to shed light on the interactions of PLA and two representative polysaccharide molecules (cellulose and chitin) and reveal structure-property relationships from a fundamental perspective using atomistic molecular dynamics. Our computational strategy was able to reproduce key experimental mechanical properties of pure and/or composite materials, reveal a decrease in immiscibility in PLA/chitin compared to PLA/cellulose associations, assert PLA-oriented polysaccharide reorientations, and explore how less effective PLA-polysaccharide hydrogen bonds are related to the poor PLA/polysaccharide miscibility. The connection between the detailed chemical interactions and the composite behavior found in this work is beneficial to the discovery of new biodegradable and natural polymer composite mixtures that can provide needed performance characteristics.
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Affiliation(s)
| | | | - Jeffrey M. Sanders
- Schrödinger,
Inc., 1540 Broadway, New York, New York10036, United States
| | - Andrea R. Browning
- Schrödinger,
Inc., 01 SW Main St #1300, Portland, Oregon 97204, United States
| | - Mathew D. Halls
- Schrödinger,
Inc., 5820 Oberlin Dr., San Diego, California 92121, United States
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2
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Sanders JM, Coscia BJ, Fonari A, Misra M, Mileo PGM, Giesen DJ, Browning AR, Halls MD. Exploring the Effects of Wetting and Free Fatty Acid Deposition on an Atomistic Hair Fiber Surface Model Incorporating Keratin-Associated Protein 5-1. Langmuir 2023; 39:5263-5274. [PMID: 37014946 DOI: 10.1021/acs.langmuir.2c03063] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
The complex development of cosmetic and medical formulations relies on an ever-growing accuracy of predictive models of hair surfaces. Hitherto, modeling efforts have focused on the description of 18-methyl eicosanoic acid (18-MEA), the primary fatty acid covalently attached to the hair surface, without explicit modeling of the protein layer. Herein, the molecular details of the outermost surface of the human hair fiber surface, also called the F-layer, were studied using molecular dynamics (MD) simulations. The F-layer is composed primarily of keratin-associated proteins KAP5 and KAP10, which are decorated with 18-MEA on the outer surface of a hair fiber. In our molecular model, we incorporated KAP5-1 and evaluated the surface properties of 18-MEA through MD simulations, resulting in 18-MEA surface density, layer thickness, and tilt angles in agreement with previous experimental and computational studies. Subsequent models with reduced 18-MEA surface density were also generated to mimic damaged hair surfaces. Response to wetting of virgin and damaged hair showed rearrangement of 18-MEA on the surface, allowing for water penetration into the protein layer. To demonstrate a potential use case for these atomistic models, we deposited naturally occurring fatty acids and measured 18-MEA's response in both dry and wet conditions. As fatty acids are often incorporated in shampoo formulations, this work demonstrates the ability to model the adsorption of ingredients on hair surfaces. This study illustrates, for the first time, the complex behavior of a realistic F-layer at the molecular level and opens up the possibility of studying the adsorption behavior of larger, more complex molecules and formulations.
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Affiliation(s)
| | | | - Alexandr Fonari
- Schrödinger, LLC, New York, New York 10036-4041, United States
| | - Mayank Misra
- Schrödinger, LLC, New York, New York 10036-4041, United States
| | | | - David J Giesen
- Schrödinger, LLC, New York, New York 10036-4041, United States
| | | | - Mathew D Halls
- Schrödinger, LLC, New York, New York 10036-4041, United States
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3
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Coscia BJ, Shelley JC, Browning AR, Sanders JM, Chaudret R, Rozot R, Léonforte F, Halls MD, Luengo GS. Shearing friction behaviour of synthetic polymers compared to a functionalized polysaccharide on biomimetic surfaces: models for the prediction of performance of eco-designed formulations. Phys Chem Chem Phys 2023; 25:1768-1780. [PMID: 36597804 DOI: 10.1039/d2cp05465e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The substitution of natural, bio-based and/or biodegradable polymers for those of petrochemical origin in consumer formulations has become an active area of research and development as the sourcing and destiny of material components becomes a more critical factor in product design. These polymers often differ from their petroleum-based counterparts in topology, raw material composition and solution behaviour. Effective and efficient reformulation that maintains comparable cosmetic performance to existing products requires a deep understanding of the differences in frictional behaviour between polymers as a function of their molecular structure. In this work, we simulate the tribological behaviour of three topologically distinct polymers in solution with surfactants and in contact with hair-biomimetic patterned surfaces. We compare a generic functionalized polysaccharide to two performant polymers used in shampoo formulations: a strongly positively charged polyelectrolyte and a zwitterionic copolymer. Topological differences are expected to affect rheological properties, as well as their direct interaction with structured biological substrates. Using a refined Martini-style coarse-grained model we describe the polymer-dependent differences in aggregation behaviour as well as selective interactions with a biomimetic model hair surface. Additionally, we introduce a formalism to characterize the response of the solution to shear as an initial study on lubrication properties, which define the sensorial performance of these systems in cosmetics (i.e., manageability, touch, etc.). The tools and techniques presented in this work illustrate the strength of molecular simulation in eco-design of formulation as a complement to experiment. These efforts help advance our understanding of how we can relate complex atomic-scale solution behaviour to relevant macroscopic properties. We expect these techniques to play an increasingly important role in advancing strategies for green polymer formulation design by providing an understanding for how new polymers could reach and even exceed the level of performance of existing polymers.
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Affiliation(s)
| | | | | | | | | | - Roger Rozot
- L'Oréal Research and Innovation, Aulnay-Sous Bois, France.
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Moore LMJ, Redeker ND, Browning AR, Sanders JM, Ghiassi KB. Polycyanurates via Molecular Dynamics: In Situ Crosslinking from Di(Cyanate Ester) Resins and Model Validation through Comparison to Experiment. Macromolecules 2021. [DOI: 10.1021/acs.macromol.1c00207] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Levi M. J. Moore
- Air Force Research Laboratory, Aerospace Systems Directorate, Edwards Air Force Base, California 93524, United States
| | - Neil D. Redeker
- Air Force Research Laboratory, Exquadrum, Incorporated, Edwards Air Force Base, California 93524, United States
| | | | | | - Kamran B. Ghiassi
- Air Force Research Laboratory, Aerospace Systems Directorate, Edwards Air Force Base, California 93524, United States
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5
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Sanders JM, Misra M, Mustard TJL, Giesen DJ, Zhang T, Shelley J, Halls MD. Characterizing moisture uptake and plasticization effects of water on amorphous amylose starch models using molecular dynamics methods. Carbohydr Polym 2021; 252:117161. [PMID: 33183612 DOI: 10.1016/j.carbpol.2020.117161] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [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: 07/01/2020] [Revised: 09/03/2020] [Accepted: 09/26/2020] [Indexed: 11/30/2022]
Abstract
Dynamics and thermophysical properties of amorphous starch were explored using molecular dynamics (MD) simulations. Using the OPLS3e force field, simulations of short amylose chains in water were performed to determine force field accuracy. Using well-tempered metadynamics, a free energy map of the two glycosidic angles of an amylose molecule was constructed and compared with other modern force fields. Good agreement of torsional sampling for both solvated and amorphous amylose starch models was observed. Using combined grand canonical Monte Carlo (GCMC)/MD simulations, a moisture sorption isotherm curve is predicted along with temperature dependence. Concentration-dependent activation energies for water transport agree quantitatively with previous experiments. Finally, the plasticization effect of moisture content on amorphous starch was investigated. Predicted glass transition temperature (Tg) depression as a function of moisture content is in line with experimental trends. Further, our calculations provide a value for the dry Tg for amorphous starch, a value which no experimental value is available.
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Affiliation(s)
| | | | | | | | - Teng Zhang
- Schrödinger Inc., New York, NY, 10036, USA
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Shipkowski KA, Sanders JM, McDonald JD, Garner CE, Doyle-Eisele M, Wegerski CJ, Waidyanatha S. Comparative disposition of dimethylaminoethanol and choline in rats and mice following oral or intravenous administration. Toxicol Appl Pharmacol 2019; 378:114592. [PMID: 31100288 DOI: 10.1016/j.taap.2019.05.011] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2019] [Revised: 04/15/2019] [Accepted: 05/10/2019] [Indexed: 12/13/2022]
Abstract
Dimethylaminoethanol (DMAE) and its salts have been used to treat numerous disorders in humans and hence safety of its use is a concern. DMAE is a close structural analog of choline, an essential nutrient. Exposure to DMAE may affect choline uptake and synthesis. The current investigation characterizes: 1) the absorption, distribution, metabolism, and excretion (ADME) of DMAE in Wistar Han rats and B6C3F1 mice following a single gavage or intravenous (IV) administration of 10, 100 or 500 mg/kg [14C]DMAE, and 2) the ADME of [14C]choline (160 mg/kg) and the effect on its disposition following pre-treatment with DMAE (100 or 500 mg/kg). In both rats and mice, following gavage administration, DMAE was excreted in urine (16-69%) and as exhaled CO2 (3-22%). The tissue retention was moderate (21-44%); however, the brain concentrations were low and there was no accumulation. Serum choline levels were not elevated following administration of DMAE. The DMAE metabolites in urine were DMAE N-oxide and N,N-dimethylglycine; the carcinogen, N-N-dimethylnitrosamine, was not detected. The pattern of disposition of [14C]choline following gavage administration was similar to that of [14C]DMAE. Prior treatment with DMAE had minimal effects on choline disposition. The pattern of disposition of [14C]DMAE and [14C]choline following IV administration was similar to gavage administration. There were minimal dose-, sex- or species-related effects following gavage or IV administration of [14C]DMAE or [14C]choline. Data from the current study did not support previous reports that: 1) DMAE alters choline uptake and distribution, or 2) that DMAE is converted into choline in vivo.
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Affiliation(s)
- K A Shipkowski
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, NC, United States of America
| | - J M Sanders
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, NC, United States of America
| | - J D McDonald
- Lovelace Biomedical and Environmental Research Institute, Albuquerque, NM, United States of America
| | - C E Garner
- Lovelace Biomedical and Environmental Research Institute, Albuquerque, NM, United States of America
| | - M Doyle-Eisele
- Lovelace Biomedical and Environmental Research Institute, Albuquerque, NM, United States of America
| | - C J Wegerski
- Lovelace Biomedical and Environmental Research Institute, Albuquerque, NM, United States of America
| | - S Waidyanatha
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, NC, United States of America.
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Shipkowski KA, Sanders JM, McDonald JD, Walker NJ, Waidyanatha S. Disposition of fullerene C60 in rats following intratracheal or intravenous administration. Xenobiotica 2019; 49:1078-1085. [PMID: 30257131 DOI: 10.1080/00498254.2018.1528646] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [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: 10/28/2022]
Abstract
Fullerene C60 is used in a variety of industrial and consumer capacities. As part of a comprehensive evaluation of the toxicity of fullerene C60 by the National Toxicology Program, the disposition following intratracheal (IT) instillation and intravenous (IV) administration of 1 or 5 mg/kg b.wt. fullerene C60 was investigated in male Fischer 344 rats. Following IT instillation, fullerene C60 was detected in the lung as early as 0.5 h post-exposure with minimal clearance over the 168 h period; the concentration increased ≥20-fold with a 5-fold increase in the dose. Fullerene C60 was not detected in extrapulmonary tissues. Following IV administration, fullerene C60 was rapidly eliminated from the blood and was undetectable after 0.5 h post-administration. The highest tissue concentrations of fullerene C60 occurred in the liver, followed by the spleen, lung and kidney. Fullerene C60 was cleared slowly from the kidney and the lung with estimated half-lives of 24 and 139 h, respectively. The liver concentration of fullerene C60 did not change much with time; over 90% of the fullerene C60 remained there over the study duration up to 168 h. Fullerene C60 was also not detected in urine or feces. These data support the hypothesis that fullerene C60 accumulates in the body and therefore has the potential to induce detrimental health effects following exposure.
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Affiliation(s)
- K A Shipkowski
- a Division of the National Toxicology Program, National Institute of Environmental Health Sciences , Research Triangle Park , NC , USA.,b ICF International, Inc , Durham , NC , USA
| | - J M Sanders
- a Division of the National Toxicology Program, National Institute of Environmental Health Sciences , Research Triangle Park , NC , USA
| | - J D McDonald
- c Lovelace Biomedical and Environmental Research Institute , Albuquerque , NM , USA
| | - N J Walker
- a Division of the National Toxicology Program, National Institute of Environmental Health Sciences , Research Triangle Park , NC , USA
| | - S Waidyanatha
- a Division of the National Toxicology Program, National Institute of Environmental Health Sciences , Research Triangle Park , NC , USA
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8
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Dunnick JK, Sanders JM, Kissling GE, Johnson CL, Boyle MH, Elmore SA. Environmental chemical exposure may contribute to uterine cancer development: studies with tetrabromobisphenol A. Toxicol Pathol 2015; 43:464-73. [PMID: 25476797 PMCID: PMC6706771 DOI: 10.1177/0192623314557335] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [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] [Indexed: 12/25/2022]
Abstract
Tetrabromobisphenol A (TBBPA), a widely used flame retardant, caused uterine tumors in rats. In this study, TBBPA was administered to male and female Wistar Han rats and B6C3F1/N mice by oral gavage in corn oil for 2 years at doses up to 1,000 mg/kg. TBBPA induced uterine epithelial tumors including adenomas, adenocarcinomas, and malignant mixed Müllerian tumors (MMMTs). In addition, endometrial epithelial atypical hyperplasia occurred in TBBPA-treated rats. Also found to be related to TBBPA treatment, but at lower incidence and at a lower statistical significance, were testicular tumors in rats, and hepatic tumors, hemangiosarcomas (all organs), and intestinal tumors in male mice. It is hypothesized that the TBBPA uterine tumor carcinogenic mechanisms involve altered estrogen levels and/or oxidative damage. TBBPA treatment may affect hydroxysteroid-dehydrogenase-17β (HSD17β) and/or sulfotransferases, enzymes involved in estrogen homeostasis. Metabolism of TBBPA may also result in the formation of free radicals. The finding of TBBPA-mediated uterine cancer in rats is of concern because TBBPA exposure is widespread and endometrial tumors are a common malignancy in women. Further work is needed to understand TBBPA cancer mechanisms.
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Affiliation(s)
- J K Dunnick
- National Institute of Environmental Health Sciences, National Toxicology Program, Research Triangle Park, North Carolina, USA
| | - J M Sanders
- National Cancer Institute, National Institutes of Health, Research Triangle Park, North Carolina, USA
| | - G E Kissling
- National Institute of Environmental Health Sciences, National Toxicology Program, Research Triangle Park, North Carolina, USA
| | - C L Johnson
- Charles River Laboratories, Pathology Associates, Research Triangle Park, North Carolina, USA
| | - M H Boyle
- Integrated Laboratory Systems, Research Triangle Park, North Carolina, USA
| | - S A Elmore
- National Institute of Environmental Health Sciences, National Toxicology Program, Research Triangle Park, North Carolina, USA
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Sanders JM, Wampole ME, Chen CP, Sethi D, Singh A, Dupradeau FY, Wang F, Gray BD, Thakur ML, Wickstrom E. Effects of hypoxanthine substitution in peptide nucleic acids targeting KRAS2 oncogenic mRNA molecules: theory and experiment. J Phys Chem B 2013; 117:11584-95. [PMID: 23972113 DOI: 10.1021/jp4064966] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Genetic disorders can arise from single base substitutions in a single gene. A single base substitution for wild type guanine in the twelfth codon of KRAS2 mRNA occurs frequently to initiate lung, pancreatic, and colon cancer. We have observed single base mismatch specificity in radioimaging of mutant KRAS2 mRNA in tumors in mice by in vivo hybridization with radiolabeled peptide nucleic acid (PNA) dodecamers. We hypothesized that multimutant specificity could be achieved with a PNA dodecamer incorporating hypoxanthine, which can form Watson-Crick base pairs with adenine, cytosine, thymine, and uracil. Using molecular dynamics simulations and free energy calculations, we show that hypoxanthine substitutions in PNAs are tolerated in KRAS2 RNA:PNA duplexes where wild type guanine is replaced by mutant uracil or adenine in RNA. To validate our predictions, we synthesized PNA dodecamers with hypoxanthine, and then measured the thermal stability of RNA:PNA duplexes. Circular dichroism thermal melting results showed that hypoxanthine-containing PNAs are more stable in duplexes where hypoxanthine-adenine and hypoxanthine-uracil base pairs are formed than single mismatch duplexes or duplexes containing hypoxanthine-guanine opposition.
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Affiliation(s)
- Jeffrey M Sanders
- Departments of Biochemistry & Molecular Biology and ∥Radiology, and ⊥Kimmel Cancer Center, Thomas Jefferson University , Philadelphia, Pennsylvania 19107, United States
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10
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Dunnick JK, Brix A, Sanders JM, Travlos GS. N,N-dimethyl-p-toluidine, a component in dental materials, causes hematologic toxic and carcinogenic responses in rodent model systems. Toxicol Pathol 2013; 42:603-15. [PMID: 23867143 DOI: 10.1177/0192623313489604] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Because of the potential for exposure to N,N-dimethyl-p-toluidine (DMPT) in medical devices and the lack of toxicity and carcinogenicity information available in the literature, the National Toxicology Program conducted toxicity and carcinogenicity studies of DMPT in male and female F344/N rats and B6C3F1/N mice. In these studies, a treatment-related macrocytic regenerative anemia characterized by increased levels of methemoglobin and Heinz body formation developed within a few weeks of DMPT exposure in rats and mice. DMPT induced nasal cavity, splenic, and liver toxicity in rats and mice at 3 months and 2 years. DMPT carcinogenic effects were seen in the liver of male and female rats and mice, the nasal cavity of male and female rats, and the lung and forestomach of female mice. In rodents, DMPT is distributed to many of the sites where toxic and carcinogenic effects occurred. DMPT-induced oxidative damage at these target sites may be one mechanism for the treatment-related lesions. Methemoglobinemia, as seen in these DMPT studies, is caused by oxidation of the heme moiety, and this end point served as an early alert for other target organ toxicities and carcinogenic responses that followed with longer term exposure.
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Affiliation(s)
- June K Dunnick
- 1National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina, USA
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Katwal AB, Konkalmatt PR, Piras BA, Hazarika S, Li SS, John Lye R, Sanders JM, Ferrante EA, Yan Z, Annex BH, French BA. Adeno-associated virus serotype 9 efficiently targets ischemic skeletal muscle following systemic delivery. Gene Ther 2013; 20:930-8. [PMID: 23535898 PMCID: PMC3758463 DOI: 10.1038/gt.2013.16] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2012] [Revised: 01/22/2013] [Accepted: 02/20/2013] [Indexed: 02/07/2023]
Abstract
Targeting therapeutic gene expression to the skeletal muscle following intravenous (IV) administration is an attractive strategy for treating peripheral arterial disease (PAD), except that vector access to the ischemic limb could be a limiting factor. As adeno-associated virus serotype 9 (AAV-9) transduces skeletal muscle at high efficiency following systemic delivery, we employed AAV-9 vectors bearing luciferase or enhanced green fluorescent protein (eGFP) reporter genes to test the hypothesis that increased desialylation of cell-surface glycans secondary to hindlimb ischemia (HLI) might help offset the reduction in tissue perfusion that occurs in mouse models of PAD. The utility of the creatine kinase-based (CK6) promoter for restricting gene expression to the skeletal muscle was also examined by comparing it with the cytomegalovirus (CMV) promoter after systemic administration following surgically induced HLI. Despite reduced blood flow to the ischemic limbs, CK6 promoter-driven luciferase activities in the ischemic gastrocnemius (GA) muscles were ∼34-, ∼28- and ∼150-fold higher than in the fully perfused contralateral GA, heart and liver, respectively, 10 days after IV administration. Furthermore, luciferase activity from the CK6 promoter in the ischemic GA muscles was ∼twofold higher than with CMV, while in the liver CK6-driven activity was ∼42-fold lower than with CMV, demonstrating that the specificity of ischemic skeletal muscle transduction can be further improved with the muscle-specific promoters. Studies with Evans blue dye and fluorescently labeled lectins revealed that vascular permeability and desialylation of the cell-surface glycans were increased in the ischemic hindlimbs. Furthermore, AAV9/CK6/Luc vector genome copy numbers were ∼sixfold higher in the ischemic muscle compared with the non-ischemic muscle in the HLI model, whereas this trend was reversed when the same genome was packaged in the AAV-1 capsid (which binds sialylated, as opposed to desialylated glycans), further underscoring the importance of desialylation in the ischemic enhancement of transduction displayed by AAV-9. Taken together, these findings suggest two complementary mechanisms contributing to the preferential transduction of ischemic muscle by AAV-9: increased vascular permeability and desialylation. In conclusion, ischemic muscle is preferentially targeted following systemic administration of AAV-9 in a mouse model of HLI. Unmasking of the primary AAV-9 receptor as a result of ischemia may contribute importantly to this effect.
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Affiliation(s)
- A B Katwal
- Division of Cardiovascular Medicine, Department of Medicine, University of Virginia, Charlottesville, VA 22903, USA
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Ronda L, Bettati S, Henry ER, Kashav T, Sanders JM, Royer WE, Mozzarelli A. Tertiary and quaternary allostery in tetrameric hemoglobin from Scapharca inaequivalvis. Biochemistry 2013; 52:2108-17. [PMID: 23458680 DOI: 10.1021/bi301620x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The clam Scapharca inaequivalvis possesses two cooperative oxygen binding hemoglobins in its red cells: a homodimeric HbI and a heterotetrameric A2B2 HbII. Each AB dimeric half of HbII is assembled in a manner very similar to that of the well-studied HbI. This study presents crystal structures of HbII along with oxygen binding data both in the crystalline state and in wet nanoporous silica gels. Despite very similar ligand-linked structural transitions observed in HbI and HbII crystals, HbII in the crystal or encapsulated in silica gels apparently exhibits minimal cooperativity in oxygen binding, in contrast with the full cooperativity exhibited by HbI crystals. However, oxygen binding curves in the crystal indicate the presence of a significant functional inequivalence of A and B chains. When this inequivalence is taken into account, both crystal and R state gel functional data are consistent with the conservation of a tertiary contribution to cooperative oxygen binding, quantitatively similar to that measured for HbI, and are in keeping with the structural information. Furthermore, our results indicate that to fully express cooperative ligand binding, HbII requires quaternary transitions hampered by crystal lattice and gel encapsulation, revealing greater complexity in cooperative function than the direct communication across a dimeric interface observed in HbI.
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Affiliation(s)
- Luca Ronda
- Department of Pharmacy, University of Parma , Parco Area delle Scienze, 23/A, 43124 Parma, Italy
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13
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Sanders JM, Wampole ME, Thakur ML, Wickstrom E. Molecular determinants of epidermal growth factor binding: a molecular dynamics study. PLoS One 2013; 8:e54136. [PMID: 23382875 PMCID: PMC3554757 DOI: 10.1371/journal.pone.0054136] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2012] [Accepted: 12/10/2012] [Indexed: 12/22/2022] Open
Abstract
The epidermal growth factor receptor (EGFR) is a member of the receptor tyrosine kinase family that plays a role in multiple cellular processes. Activation of EGFR requires binding of a ligand on the extracellular domain to promote conformational changes leading to dimerization and transphosphorylation of intracellular kinase domains. Seven ligands are known to bind EGFR with affinities ranging from sub-nanomolar to near micromolar dissociation constants. In the case of EGFR, distinct conformational states assumed upon binding a ligand is thought to be a determining factor in activation of a downstream signaling network. Previous biochemical studies suggest the existence of both low affinity and high affinity EGFR ligands. While these studies have identified functional effects of ligand binding, high-resolution structural data are lacking. To gain a better understanding of the molecular basis of EGFR binding affinities, we docked each EGFR ligand to the putative active state extracellular domain dimer and 25.0 ns molecular dynamics simulations were performed. MM-PBSA/GBSA are efficient computational approaches to approximate free energies of protein-protein interactions and decompose the free energy at the amino acid level. We applied these methods to the last 6.0 ns of each ligand-receptor simulation. MM-PBSA calculations were able to successfully rank all seven of the EGFR ligands based on the two affinity classes: EGF>HB-EGF>TGF-α>BTC>EPR>EPG>AR. Results from energy decomposition identified several interactions that are common among binding ligands. These findings reveal that while several residues are conserved among the EGFR ligand family, no single set of residues determines the affinity class. Instead we found heterogeneous sets of interactions that were driven primarily by electrostatic and Van der Waals forces. These results not only illustrate the complexity of EGFR dynamics but also pave the way for structure-based design of therapeutics targeting EGF ligands or the receptor itself.
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Affiliation(s)
- Jeffrey M. Sanders
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, Philadelphia, Pennsylvania, United States of America
| | - Matthew E. Wampole
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, Philadelphia, Pennsylvania, United States of America
| | - Mathew L. Thakur
- Department of Radiology, Thomas Jefferson Medical College, Philadelphia, Pennsylvania, United States of America
- Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, Pennsylvania, United States of America
| | - Eric Wickstrom
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, Philadelphia, Pennsylvania, United States of America
- Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, Pennsylvania, United States of America
- * E-mail:
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Liu C, Sanders JM, Pascal JM, Hou YM. Adaptation to tRNA acceptor stem structure by flexible adjustment in the catalytic domain of class I tRNA synthetases. RNA 2012; 18:213-221. [PMID: 22184460 PMCID: PMC3264908 DOI: 10.1261/rna.029983.111] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2011] [Accepted: 11/09/2011] [Indexed: 05/31/2023]
Abstract
Class I aminoacyl-tRNA synthetases (aaRSs) use a Rossmann-fold domain to catalyze the synthesis of aminoacyl-tRNAs required for decoding genetic information. While the Rossmann-fold domain is conserved in evolution, the acceptor stem near the aminoacylation site varies among tRNA substrates, raising the question of how the conserved protein fold adapts to RNA sequence variations. Of interest is the existence of an unpaired C-A mismatch at the 1-72 position unique to bacterial initiator tRNA(fMet) and absent from elongator tRNAs. Here we show that the class I methionyl-tRNA synthetase (MetRS) of Escherichia coli and its close structural homolog cysteinyl-tRNA synthetase (CysRS) display distinct patterns of recognition of the 1-72 base pair. While the structural homology of the two enzymes in the Rossmann-fold domain is manifested in a common burst feature of aminoacylation kinetics, CysRS discriminates against unpaired 1-72, whereas MetRS lacks such discrimination. A structure-based alignment of the Rossmann fold identifies the insertion of an α-helical motif, specific to CysRS but absent from MetRS, which docks on 1-72 and may discriminate against mismatches. Indeed, substitutions of the CysRS helical motif abolish the discrimination against unpaired 1-72. Additional structural alignments reveal that with the exception of MetRS, class I tRNA synthetases contain a structural motif that docks on 1-72. This work demonstrates that by flexible insertion of a structural motif to dock on 1-72, the catalytic domain of class I tRNA synthetases can acquire structural plasticity to adapt to changes at the end of the tRNA acceptor stem.
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MESH Headings
- Amino Acyl-tRNA Synthetases/chemistry
- Amino Acyl-tRNA Synthetases/genetics
- Amino Acyl-tRNA Synthetases/metabolism
- Base Pairing
- Base Sequence/genetics
- Binding Sites
- Catalytic Domain
- DNA Mutational Analysis/methods
- Escherichia coli/enzymology
- Escherichia coli/genetics
- Escherichia coli/metabolism
- Methionine-tRNA Ligase/chemistry
- Methionine-tRNA Ligase/genetics
- Methionine-tRNA Ligase/metabolism
- Molecular Sequence Data
- Mutagenesis, Insertional
- Nucleic Acid Conformation
- Protein Folding
- Protein Structure, Secondary
- RNA, Bacterial/chemistry
- RNA, Bacterial/genetics
- RNA, Bacterial/metabolism
- RNA, Transfer, Amino Acyl/chemistry
- RNA, Transfer, Amino Acyl/genetics
- RNA, Transfer, Amino Acyl/metabolism
- RNA-Binding Proteins/chemistry
- RNA-Binding Proteins/genetics
- RNA-Binding Proteins/metabolism
- Recombinant Proteins/chemistry
- Recombinant Proteins/genetics
- Recombinant Proteins/metabolism
- Sequence Alignment/methods
- Transfer RNA Aminoacylation/genetics
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Affiliation(s)
- Cuiping Liu
- Thomas Jefferson University Department of Biochemistry and Molecular Biology, Philadelphia, Pennsylvania 19107, USA
| | - Jeffrey M. Sanders
- Thomas Jefferson University Department of Biochemistry and Molecular Biology, Philadelphia, Pennsylvania 19107, USA
| | - John M. Pascal
- Thomas Jefferson University Department of Biochemistry and Molecular Biology, Philadelphia, Pennsylvania 19107, USA
| | - Ya-Ming Hou
- Thomas Jefferson University Department of Biochemistry and Molecular Biology, Philadelphia, Pennsylvania 19107, USA
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15
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Wickstrom E, Chen CP, Devadhas D, Wampole M, Jin YY, Sanders JM, Kairys JC, Ankeny ML, Hu R, Barner KE, Steiner KV, Thakur ML. Three dimensional projection environment for molecular design and surgical simulation. Stud Health Technol Inform 2011; 163:691-695. [PMID: 21335882] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
We are developing agents for positron emission tomography (PET) imaging of cancer gene mRNA expression and software to fuse mRNA PET images with anatomical computerized tomography (CT) images to enable volumetric (3D) haptic (touch-and-feel) simulation of pancreatic cancer and surrounding organs prior to surgery in a particular patient. We have identified a novel ligand specific for epidermal growth factor receptor (EGFR) to direct PET agent uptake specifically into cancer cells, and created a volumetric haptic surgical simulation of human pancreatic cancer reconstructed from patient CT data. Young's modulus and the Poisson ratio for each tissue will be adjusted to fit the experience of participating surgeons.
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Affiliation(s)
- Eric Wickstrom
- Biochemistry & Molecular Biology, Thomas Jefferson University, Philadelphia, PA 19107, USA
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16
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Sanders JM, Bucher JR, Peckham JC, Kissling GE, Hejtmancik MR, Chhabra RS. Carcinogenesis studies of cresols in rats and mice. Toxicology 2009; 257:33-9. [PMID: 19114085 PMCID: PMC2826171 DOI: 10.1016/j.tox.2008.12.005] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.9] [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: 07/28/2008] [Revised: 11/25/2008] [Accepted: 12/02/2008] [Indexed: 11/17/2022]
Abstract
Cresols, monomethyl derivatives of phenol, are high production chemicals with potential for human exposure. The three isomeric forms of cresol are used individually or in mixtures as disinfectants, preservatives, and solvents or as intermediates in the production of antioxidants, fragrances, herbicides, insecticides, dyes, and explosives. Carcinogenesis studies were conducted in groups of 50 male F344/N rats and 50 female B6C3F1 mice exposed to a 60:40 mixture of m- and p-cresols (m-/p-cresol) in feed. Rats and mice were fed diets containing 0, 1500, 5000, or 15,000 ppm and 0, 1000, 3000, or 10,000 ppm, respectively. Survival of each exposed group was similar to that of their respective control group. Mean body weight gains were depressed in rats exposed to 15,000 ppm and in mice exposed to 3000 ppm and higher. A decrease of 25% over that of controls for the final mean body weight in mice exposed to 10,000 ppm appeared to be associated with lack of palatability of the feed. A marginally increased incidence of renal tubule adenoma was observed in the 15,000-ppm-exposed rats. The increased incidence was not statistically significant, but did exceed the range of historical controls. No increased incidence of hyperplasia of the renal tubules was observed; however, a significantly increased incidence of hyperplasia of the transitional epithelium associated with an increased incidence of nephropathy was observed at the high exposure concentration. The only significantly increased incidence of a neoplastic lesion related to cresol exposure observed in these studies was that of squamous cell papilloma in the forestomach of 10,000-ppm-exposed mice. A definitive association with irritation at the site-of-contact could not be made because of limited evidence of injury to the gastric mucosa at the time of necropsy. However, given the minimal chemical-related neoplastic response in these studies, it was concluded that there was no clear evidence of carcinogenicity in male rats or female mice exposed to the cresol mixture.
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Affiliation(s)
- J M Sanders
- National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709, United States.
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17
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Kurth MAH, Dimichele D, Sexauer C, Sanders JM, Torres M, Zappa SC, Ragni M, Leonard N. Immune tolerance therapy utilizing factor VIII/von Willebrand factor concentrate in haemophilia A patients with high titre factor VIII inhibitors. Haemophilia 2007; 14:50-5. [PMID: 17941829 DOI: 10.1111/j.1365-2516.2007.01560.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Factor VIII (FVIII) inhibitors remain a serious complication of treatment for patients with haemophilia A. Immune tolerance induction (ITI) can eliminate inhibitors in the majority of patients, but there are major concerns related with this therapy. Investigators have raised the possibility that the use of FVIII/von Willebrand factor (FVIII/VWF) concentrates may improve the success rate of ITI and may shorten the duration of therapy necessary to attain tolerance. This retrospective study describes 25 patients at five institutions in the USA, who were treated with FVIII/VWF concentrate as part of their ITI. These were all patients who were considered poor prognosis because of clinical and laboratory characteristics, which made ITI less likely to be successful or because of a poor response to initial ITI with a monoclonal/recombinant FVIII concentrate. Overall success (complete tolerization) was 32% with another 40% attaining partial tolerization, but not complete tolerization. Of those patients attaining only partial tolerization, two patients ultimately discontinued ITI and had return of their high titre inhibitors. Eight percent of patients failed to attain either partial or complete tolerization and discontinued ITI. Another 24% are continuing with ITI but have titres of >10 BU. This study adds further retrospective data to the information regarding the use of FVIII/VWF concentrate in ITI.
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Affiliation(s)
- M A H Kurth
- Children's Hospitals and Clinics of Minnesota, Minneapolis, MN, USA
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18
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Sanders JM, Lebetkin EH, Chen LJ, Burka LT. Disposition of 2,2',4,4',5,5'-hexabromodiphenyl ether (BDE153) and its interaction with other polybrominated diphenyl ethers (PBDEs) in rodents. Xenobiotica 2007; 36:824-37. [PMID: 16971346 PMCID: PMC2826160 DOI: 10.1080/00498250600815906] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [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: 10/24/2022]
Abstract
The disposition of the 14C-labelled polybrominated diphenyl ether (PBDE) 2,2',4,4',5,5'-hexaBDE (BDE153) was investigated in rodents following single and multiple doses and in a mixture with radiolabelled 2,2',4,4'-tetraBDE (BDE47) and 2,2',4,4',5-pentaBDE (BDE99). In single exposure studies there was little or no effect of dose on BDE153 disposition in male rats in the range 1-100 micromol kg-1. No major sex or species differences in the in vivo fate of BDE153 were detected. BDE153 was absorbed in rats or mice following gavage by approximately 70%; retained in tissues; and poorly metabolized and slowly excreted. Mixture studies indicated that, relative to each other, more BDE47 was distributed to adipose tissue, more BDE153 accumulated in the liver, and BDE99 was metabolized to the greatest extent. BDE153 was probably retained in the liver due to minimal metabolism and elimination after 'first-pass' distribution to the tissue following gavage.
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Affiliation(s)
- J M Sanders
- Laboratory of Pharmacology and Chemistry, National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709, USA.
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19
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Chen LJ, Lebetkin EH, Sanders JM, Burka LT. Metabolism and disposition of 2,2',4,4',5-pentabromodiphenyl ether (BDE99) following a single or repeated administration to rats or mice. Xenobiotica 2006; 36:515-34. [PMID: 16769647 DOI: 10.1080/00498250600674477] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.4] [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: 10/24/2022]
Abstract
The metabolism and disposition of 14C-labelled 2,2',4,4',5-pentabromodiphenyl ether (BDE99) were studied in F344 rats and B6C3F1 mice. Approximately 85% of a 1 micromol kg-1 oral dose was absorbed by male rats and mice. Within 24 h following oral doses ranging from 0.1 to 1000 micromol kg-1 to rats, 39-47% of the dose was excreted in the faeces (including 16% unabsorbed), up to 2% was excreted in the urine, and 34-38% remained in the tissues, mostly in adipose tissue. Mice excreted more in the urine and less in the faeces than rats. Tissue accumulation was observed following repeated dosing to rats. Two dihydrohydroxy-S-glutathionyl and two S-glutathionyl conjugates of BDE99, 2,4,5-tribromophenol glucuronide, two mono-hydroxylated BDE99 glucuronides, and three mono-hydroxylated tetrabromodiphenyl ether glucuronides were identified in male rat bile. 2,4,5-Tribromophenol and its glucuronide and sulfate conjugates, were identified in male rat urine. 2,4,5-Tribromophenol, one mono-hydroxylated tetrabromodiphenyl ether, and two mono-hydroxylated BDE99 were characterized in male rat faeces. BDE99 undergoes more extensive metabolism than does BDE47. Half of the absorbed oral dose in male rats was excreted in 10 days mostly as metabolites derived from arene oxide intermediates.
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Affiliation(s)
- L-J Chen
- Laboratory of Pharmacology and Chemistry, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709, USA.
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20
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Sanders JM, Chen LJ, Lebetkin EH, Burka LT. Metabolism and disposition of 2,2',4,4'- tetrabromodiphenyl ether following administration of single or multiple doses to rats and mice. Xenobiotica 2006; 36:103-17. [PMID: 16507516 DOI: 10.1080/00498250500485107] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.4] [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: 10/25/2022]
Abstract
The metabolism and disposition of (14)C-labelled 2,2',4,4'-tetrabromodiphenyl ether (BDE47) were investigated in F344 rats and B6C3F1 mice. Approximately 75-85% of 1 micromol BDE47 kg(-1) was absorbed following oral administration to either rats or mice. Sex and species differences were observed in tissue distribution and excretion of BDE47-derived radioactivity. Absorption and distribution of (14)C to major tissues were dose-proportional in male rats from 0.1 to 1,000 micromol kg(-1). BDE47-derived radioactivity increased in all rat and mouse tissues examined following repeated daily doses of 1 micromol kg(-1). Accumulation of (14)C in tissues of mice was less than in corresponding rat tissues. Glutathione conjugates of BDE47 were excreted in rat bile. A glucuronide and a sulfate conjugate of 2,4-dibromophenol were detected in the urine of BDE47-treated rats. BDE47 appears to induce its own metabolism. Increased formation of reactive metabolites over time may correlate with toxicological effects in BDE47-treated rodents.
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Affiliation(s)
- J M Sanders
- Laboratory of Pharmacology and Chemistry, National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709, USA.
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21
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Gorenne I, Jin L, Yoshida T, Sanders JM, Sarembock IJ, Owens GK, Somlyo AP, Somlyo AV. LPP expression during in vitro smooth muscle differentiation and stent-induced vascular injury. Circ Res 2006; 98:378-85. [PMID: 16397143 DOI: 10.1161/01.res.0000202802.34727.fd] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Lipoma preferred partner (LPP) has been identified as a protein highly expressed in smooth muscle (SM) tissues. The aim of the present study was to determine mechanisms that regulate LPP expression in an in vitro model of SM cell (SMC) differentiation and in stent-induced pig coronary vessel injury. All trans-retinoic acid treatment of A404 cells induced a strong increase in LPP, as well as SM alpha-actin, SM myosin heavy chain, and smoothelin mRNA levels, in a Rho kinase (ROK)-dependent manner. Adenovirus mediated overexpression of myocardin in A404 cells significantly increased LPP mRNA expression. Interestingly, inactivation of RhoA with C3-exoenzyme or treatment with ROK inhibitors strongly inhibited myocardin mRNA expression in retinoic acid-treated A404 cells or human iliac vein SMCs. LPP silencing with short interfering RNA significantly decreased SMC migration. LPP expression was also markedly decreased in focal adhesion kinase (FAK)-null cells known to have impaired migration but rescued with inducible expression of FAK. LPP expression in FAK-null fibroblasts enhanced cell spreading. In stented pig coronary vessels, LPP was expressed in the neointima of cells lacking smoothelin and showed expression patterns identical to those of SM alpha-actin. In conclusion, LPP appears to be a myocardin-, RhoA/ROK-dependent SMC differentiation marker that plays a role in regulating SMC migration.
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Affiliation(s)
- I Gorenne
- Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, VA, USA
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22
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Sanders JM, Burka LT, Smith CS, Black W, James R, Cunningham ML. Differential Expression of CYP1A, 2B, and 3A Genes in the F344 Rat following Exposure to a Polybrominated Diphenyl Ether Mixture or Individual Components. Toxicol Sci 2005; 88:127-33. [PMID: 16107549 DOI: 10.1093/toxsci/kfi288] [Citation(s) in RCA: 105] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Polybrominated diphenyl ethers (PBDEs), used as flame retardants, have been detected in the environment and in mammalian tissues and fluids. Evidence indicates that PBDE mixtures induce CYPs through aryl hydrocarbon receptor (AhR)-dependent and -independent pathways. The present work has investigated the effects of individual components of a commercial PBDE mixture (DE71) on expression of CYP1A1, a biomarker for activation of the AhR (dioxin-like), and CYP2B and CYP3A, biomarkers for activation of the constitutive androstane and pregnanexreceptors (CAR and PXR), respectively, in the rat. Male F344 rats were dosed orally on three consecutive days with either DE71, PBDE components, 2,2',4,4'-tetraBDE (BDE47), 2,2',4,4',5-pentaBDE (BDE99), 2,2',4,4',5,5'-hexaBDE (BDE153), representative polybrominated dibenzofurans (PBDFs) present in DE71, or reference PCBs. Differential expression of target genes was determined in liver 24 h after the last dose. Quantitative PCR analysis indicated up-regulation of CYP1A1 by DE71; however, the response was weak compared to that for dioxin-like PCB126. Individual PBDE components of DE71 up-regulated CYP1A1 only at the highest administered dose (100 micromol/kg/day). Representative PBDFs efficiently up-regulated CYP1A1; therefore, they, along with other PBDFs and polybrominated dibenzodioxins detected in DE71 and individual PBDE components, may be responsible for most, if not all, dioxin-like properties previously observed for PBDEs. Conversely, PBDEs appear capable of up-regulating CYP2B and CYP3A in rats at doses similar to that for non-dioxin-like PCB153. These results indicate that in vivo PBDE-mediated toxicity would be better categorized by AhR-independent mechanisms, rather than the well-characterized AhR-dependent mechanism associated with exposure to dioxin-like chemicals.
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Affiliation(s)
- J M Sanders
- Laboratory of Pharmacology and Chemistry, National Institute of Environmental Health Sciences (NIEHS), Research Triangle Park, North Carolina 27709, USA.
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23
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Abstract
BACKGROUND The increased risk of common infectious diseases associated with child day care attendance may vary by age, health plan and parent educational level. This study determined quantitatively the risk of diarrhoeal illness and upper respiratory infection (URI) among day-care children in comparison with home-care children. It examined the extent of risks in day-care children under different conditions of three age groups, enrolled in two health plans, and from families of two levels of education. METHODS The study subjects were recruited through two health plans: a Health Maintenance Organization (HMO) and the Medicaid program in Columbia, South Carolina of the USA. The sample was collected using a household survey of children, aged 5 years or younger. The participants were contacted bimonthly for 18 months with 435 attending out-of-home day care facilities and 753 being cared for at home. The potential confounding factors of family characteristics were controlled in examining the odds ratios for day care effect on common infections in children under different conditions. RESULTS In general, risks of diarrhoeal illness and URI in day-care children are greater than in home-care children. Children younger than 1.5 years of age attending day care and covered by the Medicaid program are at the greatest risk. The difference in risks between day-care and home-care children, however, is reduced to an insignificant level for children older than 1.5 years of age and for children covered by the HMO health plan. Among day-care children, those who are covered by the Medicaid program are at a significantly higher risk than those who are covered by the HMO health plan. CONCLUSIONS Although day-care children in general suffer a greater risk of common infectious diseases, the extent of day care effect on risks of diarrhoeal illness and URI varies significantly by age and type of health insurance plan.
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Affiliation(s)
- N Lu
- Department of Public Health, Western Kentucky University, Bowling Green, KY, USA.
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Abstract
Tamoxifen (TAM), an antiestrogen, has been approved for use by women at risk for developing hormone-dependent breast cancer. Administration of TAM to pregnant CD-1 mice apparently results in reproductive tract toxicity in female offspring. However, there is little or no data describing potential TAM-induced fetal toxicity to women who may become pregnant while receiving prophylactic TAM treatment. In support of the National Toxicology Program's characterization of reproductive and developmental effects of TAM, the present work describes a capillary electrophoresis (CE)-based analytical technique used for detection of TAM and two major metabolites, N-desmethyltamoxifen (DMT), and 4-hydroxytamoxifen (4-HT) in CD-1 mouse fetal tissue. TAM-derived material was extracted from CD-1 mouse fetuses 2-12 h following TAM administration (100 mg/kg) to dams on gestation day 16. The presence of TAM, DMT, and 4-HT was confirmed in the solvent extracts by nonaqueous CE. The limit of detection of TAM by UV absorption was approximately 675 amol at a signal-to-noise ratio of 2:1. This work demonstrates both transplacental transport of TAM in CD-1 mice and a sensitive analytical technique for detecting low concentrations of TAM and similar compounds in biological tissues.
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Affiliation(s)
- J M Sanders
- Laboratory of Pharmacology and Chemistry, National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709-2233, USA.
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25
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McPherson JA, Barringhaus KG, Bishop GG, Sanders JM, Rieger JM, Hesselbacher SE, Gimple LW, Powers ER, Macdonald T, Sullivan G, Linden J, Sarembock IJ. Adenosine A(2A) receptor stimulation reduces inflammation and neointimal growth in a murine carotid ligation model. Arterioscler Thromb Vasc Biol 2001; 21:791-6. [PMID: 11348876 DOI: 10.1161/01.atv.21.5.791] [Citation(s) in RCA: 87] [Impact Index Per Article: 3.8] [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: 12/31/2022]
Abstract
Endothelial activation and leukocyte recruitment are early events in atherosclerosis and the vascular response to injury. Adenosine has anti-inflammatory effects on leukocytes and endothelial cells mediated through its A(2A) receptor. We tested the hypothesis that A(2A) activation would reduce inflammation and neointimal formation in a murine carotid ligation model. Before injury, mice were randomized to a 7-day subcutaneous infusion of a specific A(2A) receptor agonist (ATL-146e, 0.004 microg/kg per minute), vehicle control, ATL-146e plus ZM241385 (a selective A(2A) antagonist), or ZM241385 alone. Leukocyte recruitment and adhesion molecule expression were assessed at early time points, and the neointimal area was measured at 14 and 28 days after injury. Compared with control mice, ATL-146e-treated mice had significantly less neutrophil and macrophage recruitment and vascular cell adhesion molecule-1, intercellular adhesion molecule-1, and P-selectin expression in the first 7 days after injury. Neointimal area was markedly and persistently reduced by 80% at 14 and 28 days, despite termination of ATL infusion at 7 days. ATL-146e+ZM241385-treated and ZM241385-treated animals had neointimal areas similar to those of control animals, confirming that the observed effects of ATL-146e were mediated specifically by the A(2A) receptor. These data demonstrate that novel stimulation of adenosine A(2A) receptors can inhibit early inflammatory processes that are important in neointimal formation after vascular injury.
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Affiliation(s)
- J A McPherson
- Cardiovascular Division, Department of Medicine, University of Virginia Health System, Charlottesville 22908, USA
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26
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Daugherty BL, Straley KS, Sanders JM, Phillips JW, Disdier M, McEver RP, Green SA. AP-3 adaptor functions in targeting P-selectin to secretory granules in endothelial cells. Traffic 2001; 2:406-13. [PMID: 11389768 DOI: 10.1034/j.1600-0854.2001.002006406.x] [Citation(s) in RCA: 26] [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: 11/23/2022]
Abstract
P-selectin, a cell adhesion protein participating in the early stages of inflammation, contains multiple sorting signals that regulate its cell surface expression. Targeting to secretory granules regulates delivery of P-selectin to the cell surface. Internalization followed by sorting from early to late endosomes mediates rapid removal of P-selectin from the surface. We show here that the P-selectin cytoplasmic domain bound AP-2 and AP-3 adaptor complexes in vitro. The amino acid substitution L768A, which abolishes endosomal sorting and impairs granule targeting of P-selectin, reduced binding of AP-3 adaptors but not AP-2 adaptors. Turnover of P-selectin was 2.4-fold faster than turnover of transferrin receptor in AP-3-deficient mocha fibroblasts, similar to turnover of these two proteins in AP-3-competent cells, demonstrating that AP-3 function is not required for endosomal sorting. However, sorting P-selectin to secretory granules was defective in endothelial cells from AP-3-deficient pearl mice, demonstrating a role for AP-3 adaptors in granule assembly in endothelial cells. P-selectin sorting to platelet alpha-granules was normal in pearl mice, consistent with earlier evidence that granule targeting of P-selectin is mechanistically distinct in endothelial cells and platelets. These observations establish that AP-3 adaptor functions in assembly of conventional secretory granules, in addition to lysosomes and the 'lysosome-like' secretory granules of platelets and melanocytes.
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Affiliation(s)
- B L Daugherty
- Department of Cell Biology, UVa Health System, School of Medicine, PO Box 800732, Charlottesville, VA 22908-0732, USA
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27
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Sanders JM, Burka LT, Chanas B, Matthews HB. Comparative xenobiotic metabolism between Tg.AC and p53+/- genetically altered mice and their respective wild types. Toxicol Sci 2001; 61:54-61. [PMID: 11294974 DOI: 10.1093/toxsci/61.1.54] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The use of transgenic animals, such as v-Ha-ras activated (TG:AC) and p53+/- mice, offers great promise for a rapid and more sensitive assay for chemical carcinogenicity. Some carcinogens are metabolically activated; therefore, it is critical that the altered genome of either of these model systems does not compromise their capability and capacity for metabolism of xenobiotics. The present work tests the generally held assumption that xenobiotic metabolism in the TG:AC and p53+/- mouse is not inherently different from that of the respective wild type, the FVB/N and C57BL/6 mouse, by comparing each genotype's ability to metabolize benzene, ethoxyquin, or methacrylonitrile. Use of these representative substrates offers the opportunity to examine arene oxide formation, aromatic ring opening, hydroxylation, epoxidation, O-deethylation, and a number of conjugation reactions. Mice were treated by gavage with (14)C-labeled parent compound, excreta were collected, and elimination routes and rates, as well as (14)C-derived metabolite profiles in urine, were compared between relevant treatment groups. Results of this study indicated that metabolism of the 3 parent compounds was not appreciably altered between either FVB/N and TG:AC mice or C57BL/6 and p53+/- mice. Further, expression of CYP1A2, CYP2E1, CYP3A, and GST-alpha in liver of naive genetically altered mice was similar to that of corresponding wild-type mice. Thus, these results suggest that the inherent ability of TG:AC and p53+/- mice to metabolize xenobiotics is not compromised by their altered genomes and would not be a factor in data interpretation of toxicity studies using either transgenic mouse line.
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MESH Headings
- Animals
- Aryl Hydrocarbon Hydroxylases
- Autoantibodies/drug effects
- Benzene/administration & dosage
- Benzene/pharmacokinetics
- Benzene/pharmacology
- Blotting, Western
- Carbon/chemistry
- Chromatography, High Pressure Liquid
- Cytochrome P-450 CYP1A2/metabolism
- Cytochrome P-450 CYP2E1/metabolism
- Cytochrome P-450 CYP3A
- Cytochrome P-450 Enzyme System/metabolism
- Dose-Response Relationship, Drug
- Ethoxyquin/administration & dosage
- Ethoxyquin/pharmacokinetics
- Ethoxyquin/pharmacology
- Ethoxyquin/urine
- Gene Expression Regulation
- Genes, p53/drug effects
- Genes, ras/drug effects
- Glutathione Transferase/metabolism
- Heterozygote
- Immunoenzyme Techniques
- Isoenzymes/metabolism
- Liver/drug effects
- Methacrylates/administration & dosage
- Methacrylates/pharmacokinetics
- Methacrylates/pharmacology
- Mice
- Mice, Inbred C57BL
- Mice, Inbred Strains
- Mice, Transgenic/genetics
- Mice, Transgenic/metabolism
- Microsomes, Liver/drug effects
- Microsomes, Liver/enzymology
- Nitriles/administration & dosage
- Nitriles/pharmacokinetics
- Nitriles/pharmacology
- Nitriles/urine
- Oxidoreductases, N-Demethylating/metabolism
- Radioisotopes
- Xenobiotics/metabolism
- Xenobiotics/toxicity
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Affiliation(s)
- J M Sanders
- Laboratory of Pharmacology and Chemistry, National Toxicology Program, National Institute of Environmental Health Sciences, MD C3-02, P.O. Box 12233, Research Triangle Park, North Carolina 27709-2233, USA.
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28
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Bishop GG, McPherson JA, Sanders JM, Hesselbacher SE, Feldman MJ, McNamara CA, Gimple LW, Powers ER, Mousa SA, Sarembock IJ. Selective alpha(v)beta(3)-receptor blockade reduces macrophage infiltration and restenosis after balloon angioplasty in the atherosclerotic rabbit. Circulation 2001; 103:1906-11. [PMID: 11294811 DOI: 10.1161/01.cir.103.14.1906] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND alpha(v)beta(3)-Integrin receptors are upregulated in atherosclerotic arteries and play a key role in smooth muscle cell and possibly inflammatory cell migration. We hypothesized that after balloon angioplasty (BA) of atherosclerotic arteries, selective inhibition of the alpha(v)beta(3)-receptor by XT199, a small-molecule, non-peptide-selective alpha(v)beta(3)-receptor antagonist, would reduce restenosis. METHODS AND RESULTS After induction of focal atherosclerosis, rabbits underwent femoral BA and received XT199 (2.5 mg/kg IV bolus plus 2.5 mg. kg(-1). d(-1) IV; n=19) or vehicle (n=20) for 14 days. At 28 days after BA, the XT199 group had a larger lumen (0.75+/-0.26 versus 0.57+/-0.20 mm(2), P=0.03) and a smaller neointimal area (0.49+/-0.18 versus 0.68+/-0.25 mm(2), P=0.01) than the vehicle group. Angiographic analysis confirmed a 30% to 40% reduction in restenosis. Arteries harvested at 28 days after BA did not show a reduction in intima plus media smooth muscle cell content but did show a 50% reduction in macrophage cell density in the XT199 group (716+/-452 versus 1458+/-989 cells/mm(2), P<0.006). Neovessel density at 28 days was also reduced (23+/-42 versus 58+/-46 vessel cross sections/mm(2), P<0.02). Early after BA (ie, 3 to 7 days), there was a decrease in intracellular adhesion molecule-1 and vascular cell adhesion molecule-1 expression, indicative of a reduction in vascular cell activation. CONCLUSIONS Selective alpha(v)beta(3)-receptor blockade for 14 days after BA in the focally atherosclerotic rabbit significantly reduced restenosis and limited macrophage infiltration and neovascularization in the vessel wall.
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MESH Headings
- Actins/analysis
- Angioplasty, Balloon
- Animals
- Arterial Occlusive Diseases/pathology
- Arterial Occlusive Diseases/prevention & control
- Arteriosclerosis/pathology
- Arteriosclerosis/therapy
- Cell Adhesion/drug effects
- Cells, Cultured
- Chemokine CCL2/metabolism
- Cholesterol/blood
- Dose-Response Relationship, Drug
- Femoral Artery/drug effects
- Femoral Artery/metabolism
- Femoral Artery/pathology
- Imidazoles/pharmacology
- Immunohistochemistry
- Intercellular Adhesion Molecule-1/drug effects
- Intercellular Adhesion Molecule-1/metabolism
- Macrophages/drug effects
- Macrophages/pathology
- Male
- Muscle, Smooth, Vascular/cytology
- Muscle, Smooth, Vascular/drug effects
- Muscle, Smooth, Vascular/metabolism
- Rabbits
- Receptors, Vitronectin/antagonists & inhibitors
- Receptors, Vitronectin/metabolism
- Recurrence
- Time Factors
- Tunica Intima/drug effects
- Tunica Intima/metabolism
- Tunica Intima/pathology
- Tunica Media/drug effects
- Tunica Media/metabolism
- Tunica Media/pathology
- Vascular Cell Adhesion Molecule-1/drug effects
- Vascular Cell Adhesion Molecule-1/metabolism
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Affiliation(s)
- G G Bishop
- University of Virginia, Charlottesville, VA, USA
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29
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Altimier LB, Sanders JM. Can you make a merger pay off? Nurs Manag (Harrow) 2000; 31:8. [PMID: 15127629 DOI: 10.1097/00006247-200004000-00003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/29/2023]
Abstract
When three perinatal departments in three hospitals merged into a single department, the transition was complex, but cost-effective.
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Affiliation(s)
- L B Altimier
- TriHealth Neonatal Services, Cincinnati, Ohio, USA
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30
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Boyer FE, Vara Prasad JV, Domagala JM, Ellsworth EL, Gajda C, Hagen SE, Markoski LJ, Tait BD, Lunney EA, Palovsky A, Ferguson D, Graham N, Holler T, Hupe D, Nouhan C, Tummino PJ, Urumov A, Zeikus E, Zeikus G, Gracheck SJ, Sanders JM, VanderRoest S, Brodfuehrer J, Iyer K, Sinz M, Gulnik SV. 5,6-Dihydropyran-2-ones possessing various sulfonyl functionalities: potent nonpeptidic inhibitors of HIV protease. J Med Chem 2000; 43:843-58. [PMID: 10715152 DOI: 10.1021/jm990281p] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
On the basis of previous SAR findings and molecular modeling studies, a series of compounds were synthesized which possessed various sulfonyl moieties substituted at the 4-position of the C-3 phenyl ring substituent of the dihydropyran-2-one ring system. The sulfonyl substituents were added in an attempt to fill the additional S(3)' pocket and thereby produce increasingly potent inhibitors of the target enzyme. Racemic and enantiomerically resolved varieties of selected compounds were synthesized. All analogues in the study displayed decent binding affinity to HIV protease, and several compounds were shown to possess very good antiviral efficacy and safety margins. X-ray crystallographic structures confirmed that the sulfonamide and sulfonate moieties were filling the S(3)' pocket of the enzyme. However, the additional substituent did not provide improved enzymatic inhibitory or antiviral activity as compared to the resolved unsubstituted aniline. The addition of the sulfonyl moiety substitution does not appear to provide favorable pharamacokinectic parameters. Selected inhibitors were tested for antiviral activity in clinical isolates and exhibited similar antiviral activity against all of the HIV-1 strains tested as they did against the wild-type HIV-1. In addition, the inhibitors exhibited good antiviral efficacies against HIV-1 strains that displayed resistance to the currently marketed protease inhibitors.
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Affiliation(s)
- F E Boyer
- Department of Chemistry, Parke-Davis Pharmaceutical Research, Division of Warner-Lambert Company, 2800 Plymouth Road, Ann Arbor, Michigan 48105, USA
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31
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Abstract
1. The metabolism and disposition of Luminol (LMN, 3-aminophthalhydrazide), a widely used forensic and laboratory reagent that chemiluminesses upon oxidation, was determined as part of its overall toxicological characterization. 2. Radiolabelled LMN was well absorbed, metabolized and excreted following p.o. administration of a range of doses. About 90% of the total dose was recovered within 24 h of administration in urine in the form of two metabolites identified as LMN N8-glucuronide and LMN N8-sulphamic acid. 3-Aminophthalic acid, the oxidative product of LMN in the light-emitting reaction, was apparently not formed in vivo. 3. Metabolism and disposition of an i.v. administered dose was similar to that following gavage. Little or no LMN-derived radioactivity was present in tissue within 12 h post-dosing. Excretion of radioactivity in bile following i.v. injection was minimal (approximately 8% of the total dose in 6 h) and consisted of the same urinary-excreted glucuronide and sulphate conjugates. 4. LMN was not absorbed dermally in rat, potentially a major route of exposure to human. If the fate of LMN is similar between species, this compound should have little potential for either dermal absorption, bioaccumulation in tissues following other routes of exposure or chronic toxicity in humans.
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Affiliation(s)
- J M Sanders
- Laboratory of Pharmacology and Chemistry, National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709, USA.
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32
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Wiegman PJ, Barry WL, McPherson JA, McNamara CA, Gimple LW, Sanders JM, Bishop GG, Powers ER, Ragosta M, Owens GK, Sarembock IJ. All-trans-retinoic acid limits restenosis after balloon angioplasty in the focally atherosclerotic rabbit : a favorable effect on vessel remodeling. Arterioscler Thromb Vasc Biol 2000; 20:89-95. [PMID: 10634804 DOI: 10.1161/01.atv.20.1.89] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.3] [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: 11/16/2022]
Abstract
All-trans-retinoic acid (atRA) has potent in vitro effects on a number of processes involved in vascular injury and repair, such as modulating smooth muscle cell (SMC) proliferation and inducing SMC differentiation, and may play an important role in the in vivo response to vascular injury. We hypothesized that atRA would limit restenosis after balloon angioplasty through SMC-modulated changes in plaque size and vessel geometry. Balloon angioplasty was performed on rabbits with focal femoral atherosclerosis randomized to treatment with atRA or saline. At 28 days after balloon angioplasty, minimal luminal diameter was significantly larger in the atRA group (1.24+/-0.17 versus 1.12+/-0.22 mm, P=0.02). Histomorphometry confirmed a larger lumen area (0.51+/-0.20 versus 0. 34+/-0.13 mm(2), P=0.004) in the atRA group, with no difference in absolute plaque area. Internal elastic lamina and external elastic lamina areas were significantly larger in the atRA group (0.89+/-0. 27 versus 0.66+/-0.24 mm(2), P=0.001, and 1.29+/-0.38 versus 0. 98+/-0.32 mm(2), P=0.001, respectively). Vessel sections exhibited significantly more alpha-actin and desmin immunostaining (P=0.01) in the atRA-treated group. No differences in early cellular proliferation and collagen content were detected with the use of bromodeoxyuridine. In this atherosclerotic model of vascular injury, atRA limits restenosis after balloon angioplasty by effects secondary to overall vessel segment enlargement at the angioplasty site rather than by effects on plaque size or cellular proliferation. Increased alpha-actin and desmin immunostaining suggest a possible role for phenotypic modulation of SMCs in this favorable remodeling effect.
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Affiliation(s)
- P J Wiegman
- Cardiovascular Division, Department of Medicine, University of VirginiaHealth Sciences Center, Charlottesville, VA 22908, USA
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33
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Altimier LB, Sanders JM. Cross-training in 3-D. Nurs Manag (Harrow) 1999; 30:59-62. [PMID: 10765277] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/14/2023]
Abstract
With 3 hospitals and 10 perinatal nursing units, nurse leaders developed a cross-training program to unify staff for maximum flexibility, greater job satisfaction, and savings.
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Affiliation(s)
- L B Altimier
- Bethesda and Good Samaratin Hospital, Cincinnati, Ohio, USA
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34
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Manka DR, Wiegman P, Din S, Sanders JM, Green SA, Gimple LW, Ragosta M, Powers ER, Ley K, Sarembock IJ. Arterial injury increases expression of inflammatory adhesion molecules in the carotid arteries of apolipoprotein-E-deficient mice. J Vasc Res 1999; 36:372-8. [PMID: 10559677 DOI: 10.1159/000025676] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.8] [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: 11/19/2022] Open
Abstract
Recent studies demonstrate increased cellular adhesion molecule expression by neointimal endothelium overlying primary and restenotic atherosclerotic plaque. In this study, we developed an atherosclerotic mouse model of arterial injury and characterized adhesion molecule expression after injury. Sixteen apolipoprotein-E-(ApoE)-deficient mice fed a Western-type diet for 4 weeks underwent carotid artery wire denudation at week 2. For each segment, the extent of neointima formation and medial thickening, or adhesion molecule expression, were scored separately on a scale from 0 (no plaque/thickening or expression) to 3 (extensive plaque/thickening or expression) using Movat staining (n = 3) or immunohistochemical analysis (n = 13). Histology revealed significant medial thickening (1.8 +/- 0.9 vs. 0.3 +/- 0.5, p < 0. 001) versus controls and pronounced staining for monocytes/macrophages in the wall of injured vessels. Immunohistochemical analysis showed more robust expression of intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) on the luminal surface of injured arteries versus controls (2.2 +/- 0.6 vs. 1.4 +/- 0.7, p < 0.01, and 2.5 +/- 0.5 vs. 1.2 +/- 0.6, p < 0.001, respectively). Injury increased adventitial ICAM-1 expression (2.6 +/- 0.5 vs. 1.6 +/- 0.5, p < 0.002) and medial VCAM-1 expression (2.2 +/- 0.6 vs. 1.2 +/- 0. 7, p < 0.004). Thus, carotid injury results in significant medial thickening and increases adhesion molecule expression beyond that induced in ApoE-deficient mice fed a Western diet alone. The observation of macrophage infiltration into the media at sites of increased ICAM-1 and VCAM-1 expression suggests that these molecules may mediate monocyte/macrophage trafficking into the wall of injured arteries.
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Affiliation(s)
- D R Manka
- Department of Biomedical Engineering, University of Virginia, Health Sciences Centers, Charlottesville, VA 22908, USA
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35
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Kamochi M, Kamochi F, Kim YB, Sawh S, Sanders JM, Sarembock I, Green S, Young JS, Ley K, Fu SM, Rose CE. P-selectin and ICAM-1 mediate endotoxin-induced neutrophil recruitment and injury to the lung and liver. Am J Physiol 1999; 277:L310-9. [PMID: 10444525 DOI: 10.1152/ajplung.1999.277.2.l310] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The role of leukocyte adhesion molecules in endotoxin-induced organ injury was evaluated by administering intraperitoneal Salmonella enteritidis lipopolysaccharide (LPS) to wild-type (WT) mice, P-selectin-deficient mice, intercellular adhesion molecule (ICAM)-1-deficient mice, and P-selectin-ICAM-1 double-mutant mice. In WT mice, there was a sevenfold increase in the number of neutrophils present in the pulmonary vascular lavage fluid, and there were sevenfold more intracapillary neutrophils by electron-microscopic (EM) morphometry at 4 h after intraperitoneal LPS compared with that in control mice. Extravascular albumin accumulation increased approximately twofold in the lungs and liver of WT mice treated with LPS. In the double-mutant mice, although overall mortality after intraperitoneal LPS was not attenuated, there was a significant delay in mortality in the P-selectin-ICAM-1-deficient mutants compared with that in WT mice after intraperitoneal LPS (P < 0.01). Moreover, compared with LPS-treated WT mice, lung and liver extravascular albumin accumulation was significantly lower in LPS-treated P-selectin-ICAM-1 double-mutant mice. Lung myeloperoxidase activity, normalized per 1,000 circulating neutrophils, increased after endotoxin in WT and P-selectin-deficient mice but not in P-selectin-ICAM-1 double-mutant mice. In addition, lung and liver myeloperoxidase activity per 1,000 circulating neutrophils in endotoxin-treated ICAM-1-deficient mice and P-selectin-ICAM-1 double mutants was significantly lower compared with that in endotoxin-treated WT mice. These data suggest that P-selectin and ICAM-1 significantly contribute to lung and liver injury after systemic endotoxemia.
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Affiliation(s)
- M Kamochi
- Department of Internal Medicine, University of Virginia Health Sciences Center, Charlottesville, Virginia 22908, USA
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36
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Ghanayem BI, Sanders JM, Chanas B, Burka LT, Gonzalez FJ. Role of cytochrome P-450 2E1 in methacrylonitrile metabolism and disposition. J Pharmacol Exp Ther 1999; 289:1054-9. [PMID: 10215687] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/12/2023] Open
Abstract
Methacrylonitrile (MAN) is a widely used aliphatic nitrile and is structurally similar to the known rat carcinogen and suspected human carcinogen acrylonitrile (AN). There is evidence that AN is metabolized via the cytochrome P-450 (CYP) 2E1. Recently, we identified two biliary conjugates originating from the interaction of MAN and its epoxide with glutathione. Mercapturic acids formed via the degradation of the two conjugates were also identified in rat and mouse urine. Additionally, a significant portion of MAN was eliminated in the expired air as CO2 (formed via the epoxide pathway) and unchanged MAN. The objective of the present work was to determine whether CYP2E1 is involved in the oxidative metabolism of MAN as was suggested for AN. 2-14C-MAN was administered to CYP2E1-null or wild-type mice by gavage at 12 mg/kg. Although total urinary and fecal excretion of MAN-derived radioactivity was slightly different in CYP2E1-null versus wild-type mice, the ratio of mercapturic acids originating from the epoxide-glutathione versus MAN-glutathione conjugates were lower in urine of CYP2E1-null mice than in that of wild-type animals. Exhalation of MAN-derived organic volatiles (primarily parent MAN) was 12- and 42-fold greater in female and male CYP2E1-null mice than in wild-type mice, respectively. Additionally, exhalation of CO2 derived from metabolism of MAN via the CYP2E1 pathway was 3- to 5-fold greater in wild-type than in CYP2E1-null animals. Although these data indicate that CYP2E1 is the principal enzyme responsible for the oxidative metabolism of MAN, other cytochrome P-450 enzymes may be involved. Assessment of MAN metabolism in CYP2E1-null mice pretreated with 1-aminobenzotriazole (CYP inhibitor) resulted in a further decrease in oxidative metabolites of MAN. Comparison of the tissue concentrations of MAN-derived radioactivity in mouse tissues revealed that MAN-derived radioactivity is generally higher in wild-type > CYP2E1-null mice > CYP2E1-null mice pretreated with 1-aminobenzotriazole, suggesting a direct relationship between MAN oxidative metabolism and the half-life of MAN and/or its metabolites in various tissues. It is therefore concluded that MAN oxidative metabolites such as the epoxide intermediate have greater reactivity than parent MAN.
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Affiliation(s)
- B I Ghanayem
- National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina, USA.
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37
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Ragosta M, Karve M, Brezynski D, Humphries J, Sanders JM, Sarembock IJ, Gimple LW, Powers ER. Effectiveness of heparin in preventing thrombin generation and thrombin activity in patients undergoing coronary intervention. Am Heart J 1999; 137:250-7. [PMID: 9924158 DOI: 10.1053/hj.1999.v137.91541] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
BACKGROUND Thrombus is important in the pathophysiology of several complications of angioplasty, including abrupt closure and restenosis. Levels of prothrombin fragment F1.2 and fibrinopeptide A reflect thrombin generation and activity. The effect of angioplasty on levels of these markers is unclear. METHODS Patients undergoing either balloon angioplasty (n = 30) or directional atherectomy (n = 9) were treated with heparin to maintain an activated clotting time of >300 seconds. Levels of F1.2, fibrinopeptide A, and thrombin-antithrombin complex were measured in the coronary sinus and coronary artery before and after intervention. Angiograms were reviewed for lesion morphologic characteristics and dissection. RESULTS There was no evidence for thrombin generation or increased thrombin activity after angioplasty regardless of lesion morphologic characteristics, dissection, type of intervention, or blood sampling site. In fact, coronary sinus concentrations of F1.2 decreased after intervention (median 0.31 nmol/L; 25th percentile 0.26 nmol/L, 75th percentile 0.37 nmol/L) before intervention to 0.23 nmol/L (25th percentile 0.19 nmol/L, 75th percentile 0.34 nmol/L) after intervention (P =.002). CONCLUSIONS Angioplasty performed in the presence of adequate heparin inhibited thrombin even when there was complex lesion morphology or dissection. These data suggest that heparin provides satisfactory thrombin inhibition during routine angioplasty.
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Affiliation(s)
- M Ragosta
- Cardiac Catheterization Laboratory, University of Virginia Health Sciences Center, Charlottsville, VA, USA.
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38
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Watson RL, Benka O, Parthasaradhi K, Maurer RJ, Sanders JM. Spectra of Ne KαX-ray satellites and hypersatellites excited by 1.2-1.4 MeV amu-1He, C, Mg and Ar ions. ACTA ACUST UNITED AC 1999. [DOI: 10.1088/0022-3700/16/5/015] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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39
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Abstract
2-Methylimidazole (2-MI), widely used as a chemical intermediate, is also present in cigarette smoke and may form in food and forage as a result of ammoniation of simple sugars. 2-MI has been shown to be neurotoxic in several animal species and to alter serum levels of T3, T4, and thyroid-stimulating hormone (TSH) in the rat, apparently leading to hyperplasia of thyroid follicular cells. In order to better characterize 2-MI-induced toxicity, the disposition of [2-(14)C]-2-MI has been investigated following p.o. administration of either 5, 50, or 150 mg/kg to male F344 rats. Excretion data indicated that absorption of 2-MI was both rapid and proportional to dose in the range studied. Approximately 90% of the total dose was eliminated in urine within 24 h. Most of the remaining 14C was excreted in feces and as expired 14CO2. Excretion data were similar following i.v. administration of 5 mg/kg. Little or no enterohepatic circulation of compound occurred, since biliary excretion of 2-MI-derived 14C was negligible. Approximately 70% of the 14C excreted in urine, following all dosing, consisted of parent compound. High-performance liquid chromatography (HPLC) chromatograms for all treatment groups were similar, indicating that metabolism of 2-MI in rats was not affected by dose or route of administration.
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Affiliation(s)
- J M Sanders
- Laboratory of Pharmacology and Chemistry, National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina 27709, USA
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40
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Sanders JM, Burka LT, Shelby MD, Newbold RR, Cunningham ML. Determination of tamoxifen and metabolites in serum by capillary electrophoresis using a nonaqueous buffer system. J Chromatogr B Biomed Sci Appl 1997; 695:181-5. [PMID: 9271143 DOI: 10.1016/s0378-4347(97)00099-6] [Citation(s) in RCA: 35] [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] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Tamoxifen (TAM), an antiestrogen, is widely used to treat hormone-dependent breast cancer in post-menopausal women. TAM may be used as a chemopreventive agent in women of child-bearing age; however, few data exist describing potential TAM-induced fetal toxicity. In support of the National Toxicology Program's characterization of reproductive and developmental effects of TAM, this work describes an analytical technique utilizing capillary electrophoresis (CE) for the detection of circulating levels of TAM, N-desmethyltamoxifen (DMT), and 4-hydroxytamoxifen (4-HT) in maternal rodent serum. Greater than 90% of 3H-labeled TAM was extractable from serum using 98:2 hexane-isoamyl alcohol. Optimum separation of TAM, DMT, and 4-HT was obtained on a 57 cmx50 microm capillary using a nonaqueous buffer system of 1:1 methanol-acetonitrile containing 50 mM ammonium acetate and 1% acetic acid. 4-Dimethylaminopyridine was used as internal standard. Temperature and voltage were optimized at 40 degrees C and 15 kV, respectively. The limit of detection of TAM by UV detection at 214 nm was approximately 800 amol. TAM and DMT were confirmed in serum of female rats 4 h following a single oral dose of 120 mg/kg. Transplacental exposure of TAM to fetal tissue will be evaluated using this technique.
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Affiliation(s)
- J M Sanders
- National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709, USA
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41
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Barry WL, Gimple LW, Humphries JE, Powers ER, McCoy KW, Sanders JM, Owens GK, Sarembock IJ. Arterial thrombin activity after angioplasty in an atherosclerotic rabbit model: time course and effect of hirudin. Circulation 1996; 94:88-93. [PMID: 8964123 DOI: 10.1161/01.cir.94.1.88] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
BACKGROUND A 2-hour infusion of the direct thrombin inhibitor hirudin at the time of balloon angioplasty limits restenosis in the focally atherosclerotic rabbit. Although short-term administration of hirudin may have a prolonged biological effect, the effect of hirudin on vessel thrombin activity has not been previously studied in an animal model of angioplasty. We hypothesized that a short intravenous infusion of hirudin would result in prolonged inhibition of arterial wall-associated thrombin activity (ATA) after angioplasty. METHODS AND RESULTS Sixty-one rabbits received recombinant hirudin (r-hirudin)(1 mg/kg bolus plus 1 mg x kg(-1) x h(-1)x2hours) or bolus heparin (controls, 150 U/kg) intravenously at the time of femoral balloon angioplasty. ATA was measured through exposure of arterial segments ex vivo to fibrinogen and conducting an assay for fibrinopeptide A (FPA). ATA was low in nonballooned, atherosclerotic vessels (FPA=0.5+/-0.3 ng x mL(-1) x mg(-1)) but increased significantly at 24 hours after angioplasty in the heparin group (3.7+/-0.9 ng x mL(-1) x mg(-1), P<.01 versus baseline, n=9) but not in the hirudin group (FPA = 1.4+/-0.3; P=NS versus baseline, P<.02 versus heparin controls, n=8). The time course of ATA after angioplasty was assessed in 44 rabbits. Thrombin activity peaked at 48 hours and declined to baseline at 72 hours and 7 days. FPA values between the heparin and r-hirudin groups were similar at these later time points. CONCLUSIONS A 2-hour intravenous infusion of r-hirudin suppressed ATA measured 24 hours after angioplasty in the focally atherosclerotic rabbit. This prolonged biological effect may account, in part, for the reduction in restenosis seen in this model.
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Affiliation(s)
- W L Barry
- Cardiovascular Division, Department of Medicine, University of Virginia Health Sciences Center, Charlottesville 22908, USA
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42
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Abstract
1. The biological fate of the antioxidant [3-14C]ethoxyquin (EQ) was investigated in the male F344 rat and the B6C3F1 mouse following either p.o. or i.v. administration. 2. The disposition of single doses up to 25 mg/kg was similar in the rat and mouse. About 90% of a total dose was excreted in urine and faeces within 24 h post-dosing. In contrast, no more than 60% of a higher dose of 250 mg/kg was excreted within 24 h following p.o. administration. 3. Metabolism of EQ was rapid in both the rat and mouse following either p.o. or i.v. administration. Little or no parent compound was detected in cumulative 24-h excreta. 5. EQ-derived radioactivity bioaccumulated in some tissues following repeated exposure to rat of either 25 or 250 mg/kg by gavage. However, the fold-increases in concentrations of EQ-derived radioactivity in tissues following repeated administration of the higher dose were generally less than those observed following repeated administration of the lower dose. Repeated high dose administration may overcome delayed gastric emptying (observed following single dose administration of 250 mg/kg) and/or lead to auto-induction of EQ metabolism.
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Affiliation(s)
- J M Sanders
- Chemistry Branch, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709, USA
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Abstract
1. The major pathways of ethoxyquin (EQ) metabolism in both the rat and mouse are O-deethylation and conjugation to endogenous substrates. 2. The two major EQ-derived metabolites excreted in rat urine were in the form of sulphate conjugates, 1,2-dihydro-6-hydroxy-2,2,4-trimethylquinoline sulphate, and 1,2,3,4-tetrahydro-3,6-dihydroxy-4-methylene-2,2-dimethylquinoline sulphate. The latter apparently arises from an intramolecular rearrangement of the 3,4-epoxide of ethoxyquin. 3. Mouse urine contained one major glucuronide, 1,2-dihydro-6-hydroxy-2,2,4-trimethylquinoline glucuronide as well as one major sulphate conjugate, 1,2-dihydro-6-hydroxy-2,2,4-trimethylquinoline sulphate. 4. EQ-derived radioactivity was excreted in rat bile, mainly as GSH conjugates, with little unchanged EQ present. Two of the biliary metabolites are glutathione conjugates of ethoxyquin 3,4-epoxide; the third appears to be a conjugate of either ethoxyquin 7,8-epoxide or 2,2,4-trimethylquinol-6-one.
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Affiliation(s)
- L T Burka
- Chemistry Branch, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709, USA
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Wu W, Deveney EF, Datz S, Desai DD, Krause HF, Sanders JM, Vane CR, Cocke CL, Giese JP. Scaling rule for target ionization by highly charged ions at low-to-intermediate velocities. Phys Rev A 1996; 53:2367-2370. [PMID: 9913147 DOI: 10.1103/physreva.53.2367] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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Zouros TJ, Wong KL, Grabbe S, Hidmi HI, Richard P, Montenegro EC, Sanders JM, Liao C, Hagmann S, Bhalla CP. 0 degrees binary encounter electron production in 30-MeV Oq++H2, He, O2, Ne, and Ar collisions. Phys Rev A 1996; 53:2272-2280. [PMID: 9913136 DOI: 10.1103/physreva.53.2272] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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Heber O, Sampoll G, Bandong BB, Maurer RJ, Watson RL, Ben-Itzhak I, Sanders JM, Shinpaugh JL, Richard P. Multiple-electron ionization, capture, and loss by 19-MeV Fq+ (q=2-9) in collisions with Ne and Ar. Phys Rev A 1995; 52:4578-4585. [PMID: 9912796 DOI: 10.1103/physreva.52.4578] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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Sanders JM, Griffin RJ, Burka LT, Matthews HB. Toxicokinetics of the cholinomimetic compound benzyltrimethylammonium chloride in the male rat and mouse. Xenobiotica 1995; 25:303-13. [PMID: 7618356 DOI: 10.3109/00498259509061854] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
1. Benzyltrimethylammonium chloride (BTMAC)-derived radioactivity was rapidly eliminated from the F344 rat and the B6C3F1 mouse following p.o. administration of 0.63-63 mg/kg of [ring-U-14C] BTMAC. Greater than 90% of the radioactivity was excreted in urine and faeces within 24-h post-dosing. 2. BTMAC was poorly to moderately absorbed from the GI tract following p.o. administration. The percent of total dose absorbed did not exceed either 40% in the rat or 15% in the mouse. 3. Absorption was linear, but limited, over time following dermal administration of 63 mg/kg to the rat. Less than 10% of the total dose was absorbed from the skin within 24 h of BTMAC application. 4. Metabolism of BTMAC was minimal in both the rat and mouse. Toxicity (excessive cholinergic stimulation and mortality) appears to be attributable to the parent compound. 5. The limited absorption and rapid elimination of BTMAC should result in little or no bioaccumulation in tissues following repeated exposure to low levels of this compound. The results suggest that greater human health risks may be associated with acute high level exposure rather than chronic low level exposure.
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Affiliation(s)
- J M Sanders
- Chemistry Branch, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709, USA
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Abstract
PURPOSE The American Academy of Pediatrics (AAP) carried out a member survey to measure pediatricians' views of parental permission and notification for selected health services for two age groups of adolescents, the 13 to 15 year olds and the 16 to 17 year olds. METHODS Through an AAP Periodic Survey, a sample of 1000 members of the AAP were sent questionnaires to fill out and return. The response rate was 77%. RESULTS The majority of pediatricians in all groups examined believed parental permission and notification were important for general medical and surgical care. But for most other types of care delineated, related to substance abuse and sexuality, most pediatricians did not believe parental permission should be required, except for requests for abortion for 13-15 year olds. For several types of care most pediatricians believed parental notification should be required for 13-15 year olds. Older pediatricians, male pediatricians, and self-employed pediatricians were more apt to support both parental permission and notification for all types of care. When age, gender and self versus not self-employed were introduced together through a logistic regression procedure differences in views were accounted for by self versus not self-employed, and age and gender had no additional impact. CONCLUSIONS Most pediatricians supported the right of minors to seek care without parental permission for care related to substance abuse and sexuality. The majority were less likely to grant confidentiality to adolescents, particularly those 13 to 15 years.
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Affiliation(s)
- G V Fleming
- Department of Research, American Academy of Pediatrics, Elk Grove Village, IL 60009-0927
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Zouros TJ, Richard P, Wong KL, Hidmi HI, Sanders JM, Liao C, Grabbe S, Bhalla CP. Projectile-charge-state dependence of 0 degrees binary-encounter electron production in 30-MeV Oq++O2 collisions. Phys Rev A 1994; 49:R3155-R3158. [PMID: 9910736 DOI: 10.1103/physreva.49.r3155] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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Affiliation(s)
- S C Zappa
- Hematology/Oncology Clinic, Cook-Fort Worth Children's Medical Center, TX 76104
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