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Andersen NH, Hadley SW, Kelly JD, Bacon ER. Intramolecular olefinic aldehyde Prins reactions for the construction of five-membered rings. J Org Chem 2002. [DOI: 10.1021/jo00221a034] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Liu Y, Bacon ER, Ballinger K, Black CD, Illig K, McIntire GL, Wang PP, O'Neil N, Kinter L, Desai VC. Pharmacokinetics and hepatic disposition of bis[1-(ethoxycarbonyl)propyl]5-acetylamino-2,4,6-triiodoisophthalate in rats and isolated perfused rat livers. Drug Metab Dispos 2000; 28:731-6. [PMID: 10859144] [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: 02/16/2023] Open
Abstract
Bis[1-(Ethoxycarbonyl)propyl]5-acetylamino-2,4,6- triiodoisophthalate+ (NC 68183) was designed as a new computed tomography imaging agent. The purpose of this study was to determine the pharmacokinetics and metabolism of NC 68183 in conscious rats and in the isolated perfused rat liver. Animals were i.v. dosed at 69 and 690 mg of iodine/kg. Blood samples were collected at 5, 15, 30, and 60 min, and 7 days after dosing. Tissue samples (liver, kidney, and spleen) were taken at 60 min and 7 days after dosing. NC 68183 was cleared from blood in first order kinetics following an i.v. administration of 69 mg I/kg. The volume of distribution (Vss) at steady state and elimination half-life (t(1/2)) were estimated as 24 ml and 11 min. The clearance of NC 68183 from blood was changed to zero-order kinetics following administration of 690 mg/kg, and its elimination rate was 16 microg I/ml.min. The liver and spleen were the only tissues to have the nanoparticle residue at day 7 following administration. NC 68183 (75 mg of agent, 35 mg of I) was injected into the isolated perfused rat liver system. Bile flow increased from 1.0 to 1.3 microl/min/g liver following administration. The biliary excretion rate maximum was estimated as 11 microg/min/g liver. The metabolite was identified using liquid chromatography/mass spectrometry as a monocarboxylic acid product, which exclusively excreted into the bile in a soluble iodinated metabolite. Pharmacokinetics data suggested that NC 68183 primarily resides in the blood pool following an i.v. administration with a plasma half-life appropriate for blood pool imaging.
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Affiliation(s)
- Y Liu
- Nycomed Amersham, Wayne, Pennsylvania, USA.
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Estep KG, Josef KA, Bacon ER, Illig CR, Toner JL, Mishra D, Blazak WF, Miller DM, Johnson DK, Allen JM, Spencer A, Wilson SA. 1,3,5-Trialkyl-2,4,6-triiodobenzenes: novel X-ray contrast agents for gastrointestinal imaging. J Med Chem 2000; 43:1940-8. [PMID: 10821706 DOI: 10.1021/jm990407i] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [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
Examination of the gastrointestinal (GI) tract has been performed for decades using barium sulfate. Although this agent has many recognized limitations including extreme radiopacity, poor intrinsic affinity for the GI mucosa, and very high density, no alternative contrast agents have emerged which produce comparable or better contrast visualization. In fact, the various techniques of the GI radiologic examination (i.e., single contrast, double contrast, biphasic) were developed to compensate for its limitations. Each of these techniques requires complex patient manipulation to achieve adequate mucosal coating or compression to overcome the marked radiopacity of barium sulfate in order to obtain a diagnostically useful examination. A series of novel radiopaque oils, the 1,3, 5-trialkyl-2,4,6-triiodobenzenes, was designed to improve the efficacy, stability, and safety of barium formulations. These substances were prepared in two steps from 1,3,5-trichlorobenzene. Compound 17 (1,3,5-tri-n-hexyl-2,4,6-triiodobenzene), formulated as an oil-in-water emulsion, was found to be well-tolerated in rodents (mice, hamsters, rats) following acute oral and/or intraperitoneal administrations at 4 times the anticipated human clinical dose. No metabolism of 17 was detected in rat, hamster, dog, monkey, or human hepatic microsomes, suggesting the lack of oral toxicity was a consequence of poor absorption. In imaging experiments in dogs, emulsions of 17 have demonstrated excellent mucosal coating and improved radiodensity relative to barium sulfate suspensions. On the basis of the preliminary imaging and toxicity data, compound 17 was selected as a potential development candidate.
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Affiliation(s)
- K G Estep
- Nycomed Amersham Imaging, 466 Devon Park Drive, P.O. Box 6630, Wayne, Pennsylvania 19087-8630, USA.
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McIntire GL, Bacon ER, Illig KJ, Coffey SB, Singh B, Bessin G, Shore MT, Wolf GL. Time course of nodal enhancement with CT X-ray nanoparticle contrast agents: effect of particle size and chemical structure. Invest Radiol 2000; 35:91-6. [PMID: 10674452 DOI: 10.1097/00004424-200002000-00001] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
RATIONALE AND OBJECTIVES Levels of CT enhancement in rabbit lymph nodes were followed with time after subcutaneous injection of four iodinated, insoluble nanoparticle contrast agents to provide experimental support for the hypothesis that clearance of these agents is related to the chemical structure of the agent itself. The impact of particle size was also studied. METHODS Subcutaneous injections (2 x 0.25 mL) were made in the dorsum of rabbit paws with 15% suspensions of four nanoparticle contrast agents. Images were obtained at 4, 10, 24, 48, and 72 hours and 5, 7, and 14 days after injection. Average attenuation (in Hounsfield units [HU]), node volume, and total iodine uptake were estimated from the CT scans for each lymph node at each time point. RESULTS All the agents provided adequate enhancement of both the popliteal and axillary lymph nodes of the rabbit (ie, > delta100 HU). Lymph node volume appears to be related to the persistence of enhancement, with long-lived agents demonstrating the greatest increase in size. The rate of clearance from the lymph nodes is related to the structure of the agent. CONCLUSIONS Clearance of insoluble, iodinated nanoparticle contrast agents from lymph nodes can be modulated by changes in the structure of the agent itself. Using the same agent, smaller particles deliver material to the lymph nodes more quickly and clear more quickly.
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Affiliation(s)
- G L McIntire
- Nycomed Amersham, PLC, Wayne, Pennsylvania, USA.
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Abstract
RATIONALE AND OBJECTIVES The authors compared the time course and blood pool and hepatic enhancement of three different doses of liposomal iodixanol with those of iohexol. MATERIALS AND METHODS A liposomal iodixanol formulation was prepared with 200 mg of iodine per milliliter total and 80 mg of iodine per milliliter encapsulated. Twelve normal New Zealand white rabbits divided into four groups received 75-, 100-, or 150-mg encapsulated iodine per kilogram doses of liposomal iodixanol or 2 mL/kg iohexol with 300 mg of iodine per milliliter. A liver section was scanned with serial computed tomography (CT) before the injection, immediately afterward, and at 1-minute intervals for 10 minutes. Region-of-interest measurements of the aorta and liver were plotted at each time point, and contrast enhancement was plotted as a function of time and iodine dose. RESULTS All liposomal iodixanol doses produced greater liver enhancement than iohexol. Results were significant (P < .05) for 100 mg and 150 mg iodine per kilogram dose groups at time points beyond 2 minutes. Peak hepatic enhancement (change in attenuation) was 54.9 HU +/- 7.6 with iohexol, compared with 59.6 HU +/- 6.1, 73.3 HU +/- 3.6, and 104.1 HU +/- 8.8 for 75, 100, and 150 mg encapsulated iodine per kilogram doses, respectively. Hepatic enhancement increased rapidly after injection of liposomal iodixanol, plateauing 2-3 minutes later. Blood pool enhancement decreased rapidly. Steady-state liver enhancement with liposomal iodixanol increased linearly with dose. Aortic enhancement was greater with iohexol. CONCLUSION Liposomal iodixanol yielded greater hepatic enhancement at lower total iodine doses than iohexol. Although liver enhancement occurred rapidly after injection, blood pool enhancement was brief.
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Affiliation(s)
- T S Desser
- Department of Radiology, VA Palo Alto Health Care System, CA 94304, USA
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6
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Desser TS, Rubin DL, Muller H, McIntire GL, Bacon ER, Hollister KR. Interstitial MR and CT lymphography with Gd-dTPA-co-alpha, omega-diaminoPEG(1450) and Gd-dTPA-co-1,6-diaminohexane polymers: preliminary experience. Acad Radiol 1999; 6:112-8. [PMID: 12680433 DOI: 10.1016/s1076-6332(99)80490-5] [Citation(s) in RCA: 12] [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: 11/17/2022]
Abstract
RATIONALE AND OBJECTIVES The authors assessed the efficacy of two gadolinium-based polymers used as lymphotrophic contrast media for computed tomography (CT) and magnetic resonance (MR) imaging. MATERIALS AND METHODS Two gadolinium-based polymers, gadolinium diethylenetriaminepentaacetic acid (DTPA)-co-1,6-diaminohexane (NC 22181) and Gd-DTPA-co-alpha, omega-diamino-polyethylene glycol(1450) (NC-66368), were formulated at a concentration of 80 mmol/L gadolinium. Doses of 0.1, 0.25, 1.0, or 2.0 mL per paw were administered subcutaneously into the hindpaws of normal rabbits. Spin-echo T1-weighted MR imaging (1.5 T) of rabbit popliteal and iliac nodes was performed before and immediately, 10 minutes, 2-3 hours, and 24 hours after injection. CT was performed 2-3 hours after injection of the high doses only. RESULTS MR imaging revealed prompt enhancement of the popliteal nodes with both polymers at doses of 0.25 mL and above. For doses of 1.0 mL or less per paw, nodal percentage enhancement was maximal at 2 hours and then declined at 24 hours. At the highest doses, however, a reservoir of subcutaneous contrast material remained at the injection site and resulted in peak enhancement at 24 hours. At CT, popliteal node enhancement was faintly visible 2-3 hours after the administration of NC 22181. At lower doses, no enhancement was appreciable at CT. CONCLUSION At 80 mmol/L formulations, the two gadolinium-based polymers provide excellent popliteal nodal enhancement on MR images. In addition, high doses of one polymer (NC 22181) were sufficiently concentrated in popliteal nodes to be visible on CT scans. Thus, this agent may be useful for both CT and MR lymphography.
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Affiliation(s)
- T S Desser
- Department of Radiology, VA Palo Alto Health Care System, 3801 Miranda Ave, Palo Alto, CA 94304, USA
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Ketai LH, Muggenberg BA, McIntire GL, Bacon ER, Rosenberg R, Losco PE, Toner JL, Nikula KJ, Haley P. CT imaging of intrathoracic lymph nodes in dogs with bronchoscopically administered iodinated nanoparticles. Acad Radiol 1999; 6:49-54. [PMID: 9891152 DOI: 10.1016/s1076-6332(99)80061-0] [Citation(s) in RCA: 14] [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] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
RATIONALE AND OBJECTIVES The purpose of the study was to determine if airway instillation of iodinated nanoparticles results in contrast material enhancement of tracheobronchial lymph nodes in dogs. MATERIALS AND METHODS Eight dogs underwent intrabronchial instillation of iodinated nanoparticles; six dogs received 900 mg each, and two dogs received 450 mg each. Spiral computed tomography (CT) was then performed 2-34 days later. RESULTS CT scans obtained 2 days after instillation showed the presence of contrast material within the lung parenchyma but no nodal enhancement. Scans obtained 6-34 days after instillation showed enhancement of the right, left, and middle tracheobronchial lymph nodes (analogous to the mediastinal nodes in humans). Mean nodal attenuation on CT images was 117 HU +/- 43, and the mean nodal volume was 129 mm3 +/- 113. Histologic specimens of the nodes showed macrophage hyperplasia. CONCLUSION Iodinated nanoparticles instilled into small airways are transported to the tracheobronchial lymph nodes, where they result in contrast enhancement.
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Affiliation(s)
- L H Ketai
- Department of Radiology, University of New Mexico Health Sciences Center, Albuquerque 87131, USA
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Wolf GL, Shore MT, Bessin G, McIntire GL, Bacon ER, Illig KJ. Lymph node extraction of radiopaque nanoparticulates in the rabbit as measured in vivo with CT. Acad Radiol 1999; 6:55-60. [PMID: 9891153 DOI: 10.1016/s1076-6332(99)80062-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
RATIONALE AND OBJECTIVES The purpose of this study was to estimate in vivo extraction of lymphographic material in the popliteal node of the rabbit. MATERIALS AND METHODS Serial quantitative computed tomography (CT) of target tissues in four legs of two rabbits was performed after subcutaneous injection of an improved lymphographic contrast agent. Massage was used as a lymphotrophic intervention. RESULTS At 15 minutes, the mean change in Hounsfield units measured 815 in the popliteal node, 219 in afferent lymphatic vessels, and 127 in efferent lymphatic vessels. The nodal extraction of nanoparticulates from the lymph was approximately 55%. Nodal massage allowed the amount of nanoparticulate remaining in sinusoidal lymph to be estimated. CONCLUSION Functional CT performed with timed studies, proper radiopaque materials, and physiologic interventions can depict in vivo lymphatic physiology under minimally invasive conditions.
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Affiliation(s)
- G L Wolf
- Department of Radiology, Massachusetts General Hospital, Boston, USA
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McIntire GL, Bacon ER, Toner JL, Cornacoff JB, Losco PE, Illig KJ, Nikula KJ, Muggenburg BA, Ketai L. Pulmonary delivery of nanoparticles of insoluble, iodinated CT X-ray contrast agents to lung draining lymph nodes in dogs. J Pharm Sci 1998; 87:1466-70. [PMID: 9811507 DOI: 10.1021/js980060r] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Lung cancer continues to be a leading cause of death around the world. Staging of this disease is critically dependent upon the involvement or noninvolvement of the lymph nodes which drain the region of lung containing the lesion/tumor. Palpation, unenhanced CT, and lymph node excision (i.e., mediastinectomy) are currently used to ascertain the status of these regional draining lymph nodes. The work reported herein details the first efforts toward the pulmonary instillation of iodinated nanoparticles for contrast-enhanced CT of lung draining lymph nodes. The data reflect the impact of dose, time post instillation, and formulation (surfactant) upon the observed CT enhancement of the tracheobronchial lymph nodes of beagle dogs. In addition, initial safety is discussed with both macroscopic and microscopic observations. The results indicate that pulmonary instillation of small volumes of iodinated nanoparticles could be successfully used to aid staging of lung cancer by CT imaging.
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Affiliation(s)
- G L McIntire
- Nycomed, 466 Devon Park Drive, P.O. Box 6630, Wayne, Pennsylvania 19087-8630, USA.
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Silver PJ, Pagani ED, Dundore RL, de Garavilla L, Bode DC, Bacon ER. Cardiovascular activity of WIN 65579, a novel inhibitor of cyclic GMP phosphodiesterase 5. Eur J Pharmacol 1998; 349:263-8. [PMID: 9671106 DOI: 10.1016/s0014-2999(98)00209-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
This study describes the phosphodiesterase inhibitory potency and cardiovascular actions of WIN 65579 (1-cyclopentyl-3-ethyl-6-(3-ethoxy-4-pyrridyl)-1H-pyrazolo[3,4-d]p yrimidin-4-one), a potent, new cGMP phosphodiesterase 5 inhibitor. WIN 65579 is a competitive inhibitor of phosphodiesterase 5, with IC50 values of 2-3 nM for phosphodiesterase 5 from human or canine vascular sources. WIN 65579 has low affinity for phosphodiesterases 1, 2 and 3 (IC50 > 3-10 microM), and is somewhat selective for phosphodiesterase 4 (IC50 approximately 100 nM). WIN 65579 is an endothelial-dependent relaxant of rat aortic smooth muscle (EC50 = 60 nM) and lowers mean arterial blood pressure in conscious spontaneous hypertensive rats following intravenous or oral dosing. WIN 65579 also increases plasma cGMP levels, and reinstates vascular responsiveness to nitroglycerin in conscious rats that are nitroglycerin-tolerant. These data show that WIN 65579 is one of the more potent phosphodiesterase 5 inhibitors, and that WIN 65579 possesses cardiovascular activities consistent with vascular phosphodiesterase 5 inhibition in vivo.
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Affiliation(s)
- P J Silver
- Dept. of Pharmacology, Sterling Winthrop, Collegeville, PA, USA
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Wentland MP, Perni RB, Dorff PH, Brundage RP, Castaldi MJ, Carlson JA, Bailey TR, Aldous SC, Carabateas PM, Bacon ER, Kullnig RK, Young DC, Woods MG, Kingsley SD, Ryan KA, Rosi D, Drozd ML, Dutko FJ. Antiviral properties of 3-quinolinecarboxamides: a series of novel non-nucleoside antiherpetic agents. Drug Des Discov 1997; 15:25-38. [PMID: 9332829] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Novel antiherpetic 3-quinolinecarboxamides were discovered as part of a drug discovery program at Sterling Winthrop Inc. A major goal of this research was to identify novel non-nucleoside agents possessing activity against acyclovir resistant herpes simplex virus. From screening compound libraries in an HSV-2 plaque reduction assay, 1-ethyl-1,4-dihydro-4-oxo-7-(4-pyridinyl)-3-quinolinecarboxamide (1) emerged as an attractive lead structure. By modifying the quinoline ring at the 1-, 2-, 3-, 4-, and 7-positions, analogues were identified that have up to 5-fold increased in vitro potency relative to acyclovir. In a single dose mouse model of infection the 1-(4-FC6H4) analogue 17, one of the most potent derivatives in vitro, displayed comparable oral antiherpetic efficacy to acyclovir at 1/16 the dose; in a multiple dose regimen, however, it was 2-fold less potent. Mechanism of action studies indicate that these new compounds interact with a different, as yet undefined, molecular target than acyclovir.
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Affiliation(s)
- M P Wentland
- Sterling Winthrop Pharmaceuticals Research Division, Sterling Winthrop Inc., Collegeville, PA 19426-0900, USA
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12
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Gazelle GS, Wolf GL, McIntire GL, Bacon ER, Na G, Halpern EF, Toner JL. Hepatic imaging with iodinated nanoparticles: a comparison with iohexol in rabbits. Acad Radiol 1995; 2:700-4. [PMID: 9419627 DOI: 10.1016/s1076-6332(05)80438-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
RATIONALE AND OBJECTIVES We evaluated the efficacy of a particulate computed tomography (CT) contrast agent in an animal model of focal liver disease. METHODS Ethyl ester of diatrizoic acid (EEDA) is an iodinated (89 mg I/ml) nanoparticulate (200 nm) contrast agent intended for intravenous use that is currently undergoing preclinical testing in our laboratory. Focal liver abscesses were created in 11 New Zealand White rabbits. Iohexol and EEDA were administered to each animal on different days. CT scanning was performed at intervals following contrast agent administration. Liver and abscess enhancement were measured and compared. Dynamic imaging experiments in normal animals were also performed using both agents. RESULTS EEDA resulted in significantly greater enhancement of the liver and liver-to-abscess contrast than did iohexol at all time points beyond 5 min at approximately 25% of the total iodine load. During dynamic imaging, liver and aortic enhancement were greater with EEDA than with iohexol, except during a 20- to 40-sec period immediately following contrast agent administration. CONCLUSION EEDA is superior to iohexol for imaging liver abscesses. Our results suggest that liver-directed agents such as EEDA may prove to be more efficacious than currently available extracellular agents designed for liver CT scanning.
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Affiliation(s)
- G S Gazelle
- Department of Radiology, Massachusetts General Hospital, Boston 02114, USA
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13
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Singh B, Bacon ER, Lesher GY, Robinson S, Pennock PO, Bode DC, Pagani ED, Bentley RG, Connell MJ, Hamel LT. Novel and potent adenosine 3',5'-cyclic phosphate phosphodiesterase III inhibitors: thiazolo[4,5-b][1,6]naphthyridin-2-ones. J Med Chem 1995; 38:2546-50. [PMID: 7629794 DOI: 10.1021/jm00014a007] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The transformation of 3-bromo-1,6-naphthyridin-2(1H)-ones 8 to thiazolo[4,5-b][1,6]naphthyridin-2(1H)-ones 12 resulted in a 2-9-fold increase in cAMP phosphodiesterase (PDE) III inhibitory potency. Unlike the secondary binding sites on the cAMP PDE III isozyme which interact with the methyl group of milrinone (2) and CI-930 (4), the site which interacts with the 5-substituents of 1,6-naphthyridin-2(1H)-ones and the 8-substituents of thiazolo[4,5-b][1,6]naphthyridin-2(1H)-ones 12 is able to accommodate a diverse group of substituents which have different steric and electronic requirements.
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Affiliation(s)
- B Singh
- Department of Medicinal Chemistry, Sterling Winthrop Pharmaceuticals Research Division, Collegeville, Pennsylvania 19426, USA
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14
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Estep KG, Josef KA, Bacon ER, Carabateas PM, Rumney S, Pilling GM, Krafte DS, Volberg WA, Dillon K, Dugrenier N. Synthesis and structure-activity relationships of 6-heterocyclic-substituted purines as inactivation modifiers of cardiac sodium channels. J Med Chem 1995; 38:2582-95. [PMID: 7629798 DOI: 10.1021/jm00014a011] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Purine-based analogs of SDZ 211-500 (5) were prepared and evaluated as inactivation modifiers of guinea pig or human cardiac sodium (Na) channels expressed in Xenopus oocytes. Substances which remove or slow the Na channel inactivation process in cardiac tissue are anticipated to prolong the effective refractory period and increase inotropy and thus have potential utility as antiarrhythmic agents. Heterocyclic substitution at the 6-position of the purine ring resulted in compounds with increased Na activity and potency, with 5-membered heterocycles being optimal. Only minor modifications to the benzhydrylpiperazine side chain were tolerated. Selected compounds which delayed the inactivation of Na channels were found to increase refractoriness and contractility in a rabbit Langendorff heart model, consistent with the cellular mechanism. Activity in both the oocyte and rabbit heart assays was specific to the S enantiomers. Preliminary in vivo activity has been demonstrated following intravenous infusion. The most promising compound on the basis of in vitro data is the formylpyrrole (S)-74, which is 25-fold more potent than DPI 201-106 (1) in the human heart Na channel assay.
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Affiliation(s)
- K G Estep
- Department of Medicinal Chemistry, Sterling Winthrop Pharmaceuticals Research Division, Sterling Winthrop Inc., Collegeville, Pennsylvania 19426-0900, USA
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15
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Bacon ER, Dalyot N, Filon D, Schreiber L, Rachmilewitz EA, Oppenheim A. Hemoglobin switching in humans is accompanied by changes in the ratio of the transcription factors, GATA-1 and SP1. Mol Med 1995; 1:297-305. [PMID: 8529108 PMCID: PMC2229915] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
BACKGROUND Understanding the mechanism of developmental regulation of hemoglobin switching has scientific as well as clinical relevance because of the influence of fetal hemoglobin (HbF) production in adulthood on the clinical manifestation of thalassemia and sickle cell anemia. We have previously found that the normal developmental patterns of globin gene expression are recapitulated in an experimental system of primary cultures that support differentiation of erythroid progenitors. We further found that high activities of the transcriptional activators, GATA-1 and SP1, are associated with normal adult erythroid differentiation. MATERIALS AND METHODS In the present work, we have studied, the activities of GATA-1 and SP1 during differentiation of cultured erythroid progenitors derived from cord blood and from fetal livers, as well as from beta zero-thalassemia patients. RESULTS The results showed high GATA-1 binding activity and very low SP1 activity in the fetal liver cultures. This pattern was in contrast to cultures derived from normal adult peripheral blood, in which both GATA-1 and SP1 activities were high. Cord blood cultures showed an additive combination of "adult" and "fetal" patterns. The progenitors derived from a beta zero-thalassemia patient with high HbF production showed "fetal" pattern. On the other hand, in cultures of 2 beta zero-thalassemia patients without high HbF, "adult" pattern was observed. CONCLUSIONS In the present work, we show that human fetal and adult erythroid progenitors are distinct in their transcription factors, and that the commitment to fetal or adult program occurs at a very early differentiation stage. Our studies also demonstrate that under anemic stress, recruitment of fetal progenitors may occur in adulthood.
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Affiliation(s)
- E R Bacon
- Department of Hematology, Hebrew University-Hadassah Medical School, Jerusalem, Israel
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16
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Subramanyam C, Ault B, Sawutz D, Bacon ER, Singh B, Pennock PO, Kelly MD, Kraynak M, Krafte D, Treasurywala A. 6-(4-pyridinyl)-1H-1,2,3-triazolo[4,5-d]-pyrimidin-4(5H)-one: a structurally novel competitive AMPA receptor antagonist. J Med Chem 1995; 38:587-9. [PMID: 7532226 DOI: 10.1021/jm00004a003] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Affiliation(s)
- C Subramanyam
- Department of Medicinal Chemistry, Sanofi Winthrop Inc., Collegeville, Pennsylvania 19426
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17
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Dundore RL, Pagani ED, Bode DC, Bacon ER, Singh B, Lesher GY, Buchholz RA, Silver PJ. Species-dependent pharmacodynamic effects of the selective low Km cyclic AMP phosphodiesterase III inhibitors WIN 58993 and WIN 62005. J Cardiovasc Pharmacol 1995; 25:14-21. [PMID: 7723343 DOI: 10.1097/00005344-199501000-00004] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
We describe the biochemical and pharmacologic effects of two novel fused pyridinones derived from milrinone: WIN 58993 and WIN 62005. Both WIN 58993 and WIN 62005 competitively inhibit cyclic GMP-inhibitable low Km cyclic AMP phosphodiesterase (PDE III) from rat heart and canine aorta with Ki values of 25 +/- 3 and 26 +/- 5 nM, respectively, and are selective (at least 160-fold) for PDE III inhibition relative to other PDE isozymes. WIN 58993 and WIN 62005 were given to conscious, chronically instrumented rats and dogs intravenously (i.v.) or perorally (p.o.). Because the doses of WIN 58993 and WIN 62005 required to decrease mean arterial blood pressure (MAP) by 20% were estimated to be 0.9 and 0.7 mg/kg, respectively, the compounds appear to be equipotent after acute i.v. administration in rats. However, the duration of the depressor responses in rats apparently differs since MAP remained significantly decreased 6 h after i.v. or p.o. administration of WIN 58993, but returned to control levels < or = 4 h after administration of WIN 62005. WIN 58993 may be slightly less potent than WIN 62005 after acute i.v. administration to dogs since significant increases in left ventricular (LV)dP/dtmax first occurred at doses of 0.1 and 0.03 mg/kg, respectively. LVdP/dtmax significantly increased in 30 min and returned to baseline 3 h after p.o. administration of 1 mg/kg WIN 58993. After p.o. administration of 1 mg/kg WIN 62005. LVdP/dtmax was significantly increased in 30 min and remained increased for at least 6 h. These data suggest that WIN 58993 and WIN 62005 are potent, selective, p.o.-active inhibitors of PDE III.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- R L Dundore
- Department of Vascular and Biochemical Pharmacology, Sterling Winthrop Pharmaceuticals Research Division, Collegeville, Pennsylvania 19426-0900
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Wolf GL, Na GC, Gazelle GS, McIntire GL, Cannillo J, Bacon ER, Halpern E. Time-lapse quantitative computed tomography lymphography: assessing lymphatic function in vivo. Acad Radiol 1994; 1:358-63. [PMID: 9419512 DOI: 10.1016/s1076-6332(12)80009-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
RATIONALE AND OBJECTIVES Immobility and massage produce different local limb lymph flow rates. We studied their influence on accumulation of radiopaque nanoparticulates in regional lymph nodes of normal rabbits. METHODS Quantitative lymphography at 10-min intervals was used to follow the transport of subcutaneous (s.c.) nanoparticulates produced from insoluble esters of diatrizoic acid. In one design, both hindpaws received 0.5 ml of nanoparticulate s.c., and one hindpaw was massaged. In a second design, one hindpaw was injected and massaged while imaging the popliteal, presacral, and paraaortic nodes every 10 min. RESULTS Gentle massage rapidly increased popliteal node accumulation in comparison with the immobile limb. On the massaged side, mean Hounsfield (HU) units, maximum Hounsfield units, and calculated iodine were significantly greater at 10 min and all subsequent times. In the node transfer experiments, it took 12, 30, and 45 min, respectively, to obtain 100-HU mean attenuation; 200-HU maximum attenuation thresholds were achieved at 20, 47, and 69 min, respectively. CONCLUSION Quantitative computed tomography lymphography reflects local lymph physiology. Gentle massage of the s.c. injection site is a powerful lymphotropic stimulus.
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Affiliation(s)
- G L Wolf
- Center for Imaging and Pharmaceutical Research, Massachusetts General Hospital, Charlestown 02129-2060, USA
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Gazelle GS, Wolf GL, McIntire GL, Bacon ER, Halpern EF, Cooper ER, Toner JL. Nanoparticulate computed tomography contrast agents for blood pool and liver-spleen imaging. Acad Radiol 1994; 1:373-6. [PMID: 9419514 DOI: 10.1016/s1076-6332(12)80011-0] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
RATIONALE AND OBJECTIVES We investigated the properties of a group of iodine-containing, insoluble compounds formulated as nanoparticles for use as potential blood pool and liver-spleen contrast agents. METHODS High-resolution, quantitative computed tomography (CT) was performed prior to and at intervals following the intravenous administration of the contrast agents to rabbits. Time-density characteristics for three organs were evaluated. RESULTS Excellent enhancement of blood (< or = 232 Hounsfield units [HU]), liver (< or = 263 HU), and spleen (< or = 350 HU) was achieved at the administered dose of 3.0 ml/kg. The composition of the agents influenced the biodistribution, as well as the residence time in blood, and time to peak enhancement in liver. CONCLUSION Iodinated nanoparticulate compounds are promising CT contrast agents. Development of agents with desirable pharmacokinetic and biodistribution profiles may permit application-specific contrast enhancement.
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Affiliation(s)
- G S Gazelle
- Center for Imaging and Pharmaceutical Research, Massachusetts General Hospital, Harvard Medical School, Boston, USA
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Wolf GL, Gazelle GS, McIntire GL, Bacon ER, Toner JL, Cooper ER, Haley PJ. Percutaneous computed tomography lymphography in the rabbit by subcutaneously injected nanoparticulates. Acad Radiol 1994; 1:352-7. [PMID: 9419511 DOI: 10.1016/s1076-6332(12)80008-0] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
RATIONALE AND OBJECTIVES Surgical lymphangiography is infrequently used in staging cancer because of its inherent limitations. Radiopaque nanoparticulates target lymph nodes draining interstitial tissues and could make percutaneous lymphography feasible. METHODS Experimental nanoparticulate contrast agent formulations were injected subcutaneously in the forepaw or hindpaw of normal rabbits or rabbits with induced reactive nodal hyperplasia. Axillary and popliteal nodes were imaged with thin-section computed tomography (CT) using quantitative methods to measure node enhancement. Dose-response (0.1-2.0 ml) and time course (4 hr to 10 weeks) of enhancement were assessed. RESULTS Nodal enhancement above 100 Hounsfield units was consistently obtained. Enhancement was significantly related to dose and peaked at 10 hr with slow washout over the observation period. Nodes with reactive hyperplasia were larger and had heterogeneous enhancement patterns distinctly different from normal nodes. CONCLUSION Percutaneous CT lymphography effectively depicts the macroscopic intranodal architecture in rabbits.
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Affiliation(s)
- G L Wolf
- Center for Imaging and Pharmaceutical Research, Massachusetts General Hospital, Charlestown 02129-2060, USA
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Pagani ED, Dundore RL, Bode DC, Bacon ER, Singh B, Lesher GY, Buchholz RA, Silver PJ. Pharmacologic and pharmacodynamic effects of the selective low Km cyclic AMP phosphodiesterase III inhibitors WIN 63291 and WIN 62582. J Cardiovasc Pharmacol 1994; 24:403-10. [PMID: 7528296] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
We describe the biochemical, pharmacologic, and in vivo pharmacodynamic profiles of two novel inhibitors of the cyclic GMP-inhibitable, low Km cyclic AMP phosphodiesterase (PDE) III; WIN 63291, a 6-quinolinyl analogue of the prototypic PDE III inhibitor milrinone and WIN 62582, an imidazopyridinone. Both WIN 62582 and WIN 63291 competitively inhibit PDE III from rat, dog, and human heart and from rat and canine aorta with IC50 values of 5-37 and 55-80 nM, respectively; the IC50 values for milrinone ranged from 300 to 520 nM. WIN 62582 and WIN 63291 are at least 1,000-fold selective for PDE III relative to inhibition of PDE isozymes I, II, IV, and V. We evaluated WIN 62582 and WIN 63291 in conscious rats and dogs after intravenous (i.v.) and oral (p.o.) administration. The dose of WIN 62582 required to reduce mean arterial blood pressure (MAP) by 20% (ED20) in rats was 1.8 mg/kg, with a pharmacodynamic duration of action of approximately 2 h. In comparison, the estimated i.v. ED20 for WIN 63291 in rats was 0.4 mg/kg, with a pharmacodynamic duration of action > 6 h. In conscious dogs, the i.v. doses of WIN 62582 and 63291 required to increase left ventricular (LV)dP/dtmax significantly were 0.1 and 0.01 mg/kg, respectively. In dogs, WIN 63291 0.1 mg/kg p.o. increased LVdP/dtmax by 86% in 30 min; LVdP/dtmax remained increased by 60% for at least 6 h. In comparison, WIN 62582, 0.3 mg/kg p.o., increased LVdP/dt by 56% in 30 min and remained increased by 40% at 6 h.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- E D Pagani
- Department of Vascular and Biochemical Pharmacology, Sterling Winthrop Pharmaceuticals Research Division, Collegeville, Pennsylvania 19426
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Gazelle GS, Wolf GL, Bacon ER, McIntire GL, Cooper ER, Toner JL. Nanocrystalline computed tomography contrast agents for blood-pool and liver-spleen imaging. Invest Radiol 1994; 29 Suppl 2:S286-8. [PMID: 7928258 DOI: 10.1097/00004424-199406001-00098] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Affiliation(s)
- G S Gazelle
- Center For Imaging and Pharmaceutical Research, Massachusetts General Hospital, Harvard Medical School, Boston
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Singh B, Bacon ER, Robinson S, Fritz RK, Lesher GY, Kumar V, Dority JA, Reuman M, Kuo GH, Eissenstat MA. Novel cAMP PDE III inhibitors: imidazo[4,5-b]pyridin-2(3H)-ones and thiazolo[4,5-b]pyridin-2(3H)-ones and their analogs. J Med Chem 1994; 37:248-54. [PMID: 8295212 DOI: 10.1021/jm00028a007] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The transformation of milrinone to 1,3-dihydro-5-methyl-6-(4-pyridinyl)-2H-imidazo[4,5-b]pyridin-2-one (13a), 5-methyl-6-(4-pyridinyl)thiazolo[4,5-b]pyridin-2(3H)-one (51), and 7-methyl-6-(4-pyridinyl)-1,8-naphthyridin-2(1H)-one (22) resulted in very potent cAMP PDE III inhibitors with in vitro activity in the nanomolar range. 1,3-Dihydro-2H-imidazo[4,5-b]pyridin-2-ones 13 were prepared from 2-aminopyridine-3-carboxylic acids (7, 10) via Curtius rearrangement. 1,8-Naphthyridin-2(1H)-one 22 and the corresponding 3,4-dihydro derivative 28 were prepared from 5-bromo-2-methyl[3,4'-bipyridin]-6-amine (21) and 5-bromo-2-methyl[3,4-bipyridin]-6(1H)-one (24), respectively, via Heck reaction. Thiazolo[4,5-b]pyridin-2(3H)-ones 35 were prepared from 6-bromo[3,4'-bipyridin]-6-amines 30 and 32 via a four-step sequence. Treatment of 6-amino-2-methyl[3,4'-bipyridine]-5-thiol (59) with ethyl bromoacetate and ethyl bromodifluoroacetate gave pyridothiazinones 60 and 61, respectively.
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Affiliation(s)
- B Singh
- Sterling Winthrop Pharmaceuticals Research Division, Collegeville, Pennsylvania 19426
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Wentland MP, Perni RB, Dorff PH, Brundage RP, Castaldi MJ, Bailey TR, Carabateas PM, Bacon ER, Young DC, Woods MG. 3-Quinolinecarboxamides. A series of novel orally-active antiherpetic agents. J Med Chem 1993; 36:1580-96. [PMID: 8388470 DOI: 10.1021/jm00063a008] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.0] [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: 01/30/2023]
Abstract
A series of novel 3-quinolinecarboxamides that are structurally similar to the quinolone class of antibacterial agents possess excellent antiherpetic properties. By modifying the quinoline ring at the 1-, 2-, 3-, and 7-positions, analogues were identified that have up to 5-fold increased HSV-2 plaque-reduction potency relative to acyclovir. In a single-dose mouse model of infection, one of the most potent derivatives in vitro, 1-(4-fluorophenyl)-1,4-dihydro-4-oxo-7-(4-pyridinyl)-3-quinolinecarbo xamide (97), displayed comparable oral antiherpetic efficacy to acyclovir at 1/16 the dose; in a multiple-dose regimen, however, 97 was 2-fold less potent. In mice dosed orally with 97, sustained plasma drug levels were evident that may account for the high efficacy observed. The molecular mechanism of action of these agents is not known; however, based on in vitro studies with acyclovir resistant mutants, it is likely that the mechanism differs from that of acyclovir. In vitro plaque-reduction potency was not generally predictive of oral efficacy in mice. An X-ray crystal structure of 97 corroborated the assignment of structure and provided useful insights as to the effect of conformation on plaque-reduction potency.
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Affiliation(s)
- M P Wentland
- Department of Medicinal Chemistry, Sterling Winthrop Pharmaceuticals Research Division, Sterling Winthrop Inc., Collegeville, Pennsylvania 19426-0900
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Bacon ER, Sytkowski AJ. Identification and characterization of a differentiation-specific antigen on normal and malignant murine erythroid cells. Blood 1987; 69:103-8. [PMID: 3466654] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Rauscher murine erythroleukemia cells grow continuously in vitro and undergo terminal differentiation in response to the physiological inducer erythropoietin. In the course of this developmental process they express many erythroid-specific markers. In order to investigate the expression of cell surface determinants during Rauscher cell differentiation we generated monoclonal antibodies to uninduced cells. Using an anti-Rauscher cell monoclonal antibody, we have identified a cell surface determinant, designated ERY-1, that is present on normal murine erythroid cells. This determinant is apparently absent from the early progenitor BFU-E, but is present on the more mature progenitors CFU-E and CFC-E. It disappears during erythroid maturation and is absent from the mature erythrocyte. This pattern of ERY-1 expression is exhibited with remarkable fidelity during the erythropoietin-induced differentiation of Rauscher cells. Such differentiation-specific expression of the ERY-1 determinant suggests that it may play a functional role in erythropoiesis.
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Bacon ER, Sing AP, Troutner JC, Reinisch CL. T-cell regulation of erythropoiesis during acute lymphoblastic leukemia. Exp Hematol 1985; 13:104-10. [PMID: 3871705] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
How and where erythropoiesis is maintained during advanced leukemic disease is an important and, as yet, unresolved question in hematology. To address the potential role of T-lymphocytes as cells that regulate CFU-E differentiation during leukemogenesis, an experimental model of disease has been developed in inbred Balb/c mice. Specifically, three-week-old Balb/c By mice were injected with murine sarcoma virus-murine leukemia virus-Moloney (MSV-MuLV-M), which resulted 6-8 months later in the development of immunoblastic T-cell sarcomas with a leukemic phase. Splenic T cells from either normal or tumor-bearing mice were assessed for their relative ability to modulate erythroid differentiation. Quantitatively, T cells, Ly1 or Ly 2,3 T-cell subsets isolated from tumor-bearing animals significantly enhanced erythropoiesis when compared with comparable normal T-cell subsets. These data suggest that the compensatory shift of erythropoiesis from the bone marrow to the spleen observed during leukemogenesis was facilitated by splenic T cells. In this circumstance, the enhanced erythropoietic function may be mediated by splenic T cells, which are selectively activated by virus.
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Abstract
A series of Thy-1.2+ Ly-1+ Qa-1+ malignant T cell clones have been isolated from murine sarcoma virus-murine leukemia-Moloney (MSV-MuLV-M)-induced B cell lymphomas or from MSV-MuLV-M-infected B6 mice. These T cell clones enhance both antigen-independent and -dependent lymphocyte differentiation and function. They also induce the differentiation of granulocytes and erythrocytes in the stem cell compartment, a function that parallels the immunopathology of the disease in vivo. The malignant T cell appears to sustain B lymphoma growth in vivo by releasing a factor (BCGF) that promotes B cell proliferation.
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Bacon ER, Sing AP, Reinish CL. Amplification of granulopoiesis by T cell subpopulations. Exp Hematol 1983; 11:747-56. [PMID: 6226533] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Regulation of granulopoiesis by activated splenic T lymphocyte subpopulations was investigated. The addition of syngeneic T cells activated by the mitogen concanavalin A or by mixed lymphocyte response (MLR) to normal bone marrow cultures stimulated granulopoiesis, while, in contrast, resting T cells did not. Functional analyses of Fluorescence Activated Cell Sorter (FACS) purified subpopulations of MLR activated T cells showed that both subsets enhanced granulocyte colony forming cells (CFUc) differentiation. Further studies using Ly 23+ T cells stimulated in vitro to suppress the primary generation of plaque forming cells (PFC) showed that these "suppressor cells" simultaneously enhanced CFUc differentiation. These results show that T cell "helper" function in hematopoietic regulation is not restricted to the inducer subset of T cells.
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Handler ES, Handle EE, Bacon ER. In vitro colony formation in bone marrow and spleen cell suspensions from rats with an acute myelogenous leukemia. J Lab Clin Med 1974; 84:249-57. [PMID: 4526416] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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