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Graf JA, Gusset M, Reid C, van Rensburg SJ, Slotow R, Somers MJ. Evolutionary ecology meets wildlife management: artificial group augmentation in the re-introduction of endangered African wild dogs (Lycaon pictus). Anim Conserv 2006. [DOI: 10.1111/j.1469-1795.2006.00048.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Venkatakrishnan K, Schmider J, Harmatz JS, Ehrenberg BL, von Moltke LL, Graf JA, Mertzanis P, Corbett KE, Rodriguez MC, Shader RI, Greenblatt DJ. Relative contribution of CYP3A to amitriptyline clearance in humans: in vitro and in vivo studies. J Clin Pharmacol 2001; 41:1043-54. [PMID: 11583471 DOI: 10.1177/00912700122012634] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.3] [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: 11/16/2022]
Abstract
The relative contribution of cytochrome P450 3A (CYP3A) to the oral clearance of amitriptyline in humans has been assessed using a combination of in vitro approaches together with a clinical pharmacokinetic interaction study using the CYP3A-selective inhibitor ketoconazole. Lymphoblast-expressed CYPs were used to study amitriptyline N-demethylation and E-10 hydroxylation in vitro. The relative activity factor (RAF) approach was used to predict the relative contribution of each CYP isoform to the net hepatic intrinsic clearance (sum of N-demethylation and E-10 hydroxylation). Assuming no extrahepatic metabolism, the model-predicted contribution of CYP3A to net intrinsic clearance should equal the fractional decrement in apparent oral clearance of amitriptyline upon complete inhibition of the enzyme. This hypothesis was tested in a clinical study of amitriptyline (50 mg, p.o.) with ketoconazole (three 200 mg doses spaced 12 hours apart) in 8 healthy volunteers. The RAF approach predicted CYP2C19 to be the dominant contributor (34%), with a mean 21% contribution of CYP3A (range: 8%-42% in a panel of 12 human livers). The mean apparent oral clearance of amitriptyline in 8 human volunteers was decreased from 2791 ml/min in the control condition to 2069 ml/min with ketoconazole. The average 21% decrement (range: 2%-40%) was identical to the mean value predicted in vitro using the RAF approach. The central nervous system (CNS) sedative effects of amitriptyline were slightly greater when ketoconazole was coadministered, but the differences were not statistically significant. In conclusion, CYP3A plays a relatively minor role in amitriptyline clearance in vivo, which is consistent with in vitro predictions using the RAF approach.
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Affiliation(s)
- K Venkatakrishnan
- Department of Pharmacology and Experimental Therapeutics, Tufts University School of Medicine and New England Medical Center, Boston, MA 02111, USA
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Toney LM, Cattoretti G, Graf JA, Merghoub T, Pandolfi PP, Dalla-Favera R, Ye BH, Dent AL. BCL-6 regulates chemokine gene transcription in macrophages. Nat Immunol 2000; 1:214-20. [PMID: 10973278 DOI: 10.1038/79749] [Citation(s) in RCA: 148] [Impact Index Per Article: 6.2] [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: 11/09/2022]
Abstract
The transcriptional repressor protein BCL-6, implicated in the pathogenesis of B cell lymphoma, regulates lymphocyte differentiation and inflammation. We investigated the mechanism for the T helper cell subset 2 (TH2)-type inflammation that occurs in BCL-6-/- mice. Using chimeric mice we found that the TH2-type inflammation is dependent upon nonlymphoid cells. We identified three chemokines, MCP-1, MCP-3 and MRP-1, which are negatively regulated by BCL-6 in macrophages. Promoter analysis revealed that BCL-6 is a potent repressor of MCP-1 transcription. Our results provide a mechanism for the regulation of TH2-type inflammation by BCL-6 and link TH2 differentiation to innate immunity.
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Affiliation(s)
- L M Toney
- Department of Microbiology and Immunology, Walther Oncology Center, Indiana University School of Medicine, Indianapolis, IN 46202, USA
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Greenblatt DJ, von Moltke LL, Harmatz JS, Durol AL, Daily JP, Graf JA, Mertzanis P, Hoffman JL, Shader RI. Differential impairment of triazolam and zolpidem clearance by ritonavir. J Acquir Immune Defic Syndr 2000; 24:129-36. [PMID: 10935688 DOI: 10.1097/00126334-200006010-00007] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND The viral protease inhibitor ritonavir has the capacity to inhibit and induce the activity of cytochrome P450-3A (CYP3A) isoforms, leading to drug interactions that may influence the efficacy and toxicity of other antiretroviral therapies, as well as pharmacologic treatments of coincident or complicating diseases. METHODS The inhibitory effect of ritonavir on the biotransformation of the hypnotic agents triazolam and zolpidem was tested in vitro using human liver microsomes. In a double-blind clinical study, volunteer study subjects received 0.125 mg triazolam or 5.0 mg zolpidem concurrent with low-dose ritonavir (four doses of 200 mg), or with placebo. RESULTS Ritonavir was a potent in vitro inhibitor of triazolam hydroxylation but was less potent as an inhibitor of zolpidem hydroxylation. In the clinical study, ritonavir reduced triazolam clearance to < 4% of control values (p < .005), prolonged elimination half-life (41 versus 3 hours; p < .005), and magnified benzodiazepine agonist effects such as sedation and performance impairment. In contrast, ritonavir reduced zolpidem clearance to 78% of control values (p < .08), and slightly prolonged elimination half-life (2.4 versus 2.0 hours; NS). Benzodiazepine agonist effects of zolpidem were not altered by ritonavir. CONCLUSION Short-term low-dose administration of ritonavir produces a large and significant impairment of triazolam clearance and enhancement of clinical effects. In contrast, ritonavir produced small and clinically unimportant reductions in zolpidem clearance. The findings are consistent with the complete dependence of triazolam clearance on CYP3A activity, compared with the partial dependence of zolpidem clearance on CYP3A.
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Affiliation(s)
- D J Greenblatt
- Department of Pharmacology and Experimental Therapeutics, Tufts University School of Medicine, New England Medical Center, Boston, Massachusetts 02111, USA.
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Greenblatt DJ, von Moltke LL, Harmatz JS, Durol AL, Daily JP, Graf JA, Mertzanis P, Hoffman JL, Shader RI. Alprazolam-ritonavir interaction: implications for product labeling. Clin Pharmacol Ther 2000; 67:335-41. [PMID: 10801241 DOI: 10.1067/mcp.2000.105757] [Citation(s) in RCA: 99] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
BACKGROUND Pharmacokinetic interactions involving antiretroviral therapies may critically influence the efficacy and toxicity of these drugs, as well as pharmacologic treatments of coincident or complicating diseases. The viral protease inhibitor ritonavir is of particular concern since it both inhibits and induces the activity of cytochrome P450 3A (CYP3A) isoforms. METHODS The inhibitory effect of ritonavir on the metabolism of alprazolam, a CYP3A-mediated reaction in humans, was tested in vitro using human liver microsomes. In a double-blind clinical study, volunteer subjects received 1.0 mg of alprazolam concurrent with low-dose ritonavir (four doses of 200 mg) or with placebo. RESULTS Ritonavir was a potent in vitro inhibitor of alprazolam hydroxylation. The 50% inhibitory concentration was 0.11 micromol/L (0.08 microg/mL); this is below the usual therapeutic plasma concentration range (generally exceeding 2 microg/mL). In the clinical study, ritonavir reduced alprazolam clearance to 41% of control values (P < .001), prolonged elimination half-life (mean values, 30 versus 13 hours; P < .005), and magnified benzodiazepine agonist effects such as sedation and performance impairment. CONCLUSION Consistent with in vitro results, administration of low doses of ritonavir for a short duration of time resulted in large impairment of alprazolam clearance and enhancement of clinical effects. Removal from product labeling of a warning against coadministration of ritonavir and alprazolam was based on a previous study only of extended exposure to ritonavir, in which CYP3A induction offset inhibition. Kinetic interactions involving antiretroviral therapies may be complex and time dependent. Product labeling should reflect this complexity.
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Affiliation(s)
- D J Greenblatt
- Department of Pharmacology and Experimental Therapeutics, Tufts University School of Medicine and New England Medical Center, Boston, MA 02111, USA.
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Greenblatt DJ, von Moltke LL, Harmatz JS, Mertzanis P, Graf JA, Durol AL, Counihan M, Roth-Schechter B, Shader RI. Kinetic and dynamic interaction study of zolpidem with ketoconazole, itraconazole, and fluconazole. Clin Pharmacol Ther 1998; 64:661-71. [PMID: 9871431 DOI: 10.1016/s0009-9236(98)90057-1] [Citation(s) in RCA: 67] [Impact Index Per Article: 2.6] [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
BACKGROUND Azole antifungal agents may impair hepatic clearance of drugs metabolized by cytochrome P450-3A isoforms. The imidazopyridine hypnotic agent zolpidem is metabolized in humans in part by P450-3A, as well as by a number of other cytochromes. Potential interactions of zolpidem with 3 commonly prescribed azole derivatives were evaluated in a controlled clinical study. METHODS In a randomized, double-blind, 5-way, crossover, clinical pharmacokinetic-pharmacodynamic study, 12 volunteers received (A) zolpidem placebo plus azole placebo, (B) 5 mg zolpidem plus azole placebo (C) zolpidem plus ketoconazole, (D) zolpidem plus itraconazole, and (E) zolpidem plus fluconazole. RESULTS Mean apparent oral clearance of zolpidem when given with placebo was 422 mL/min, and elimination half-life was 1.9 hours. Clearance was significantly reduced to 250 mL/min when zolpidem was given with ketoconazole, and half-life was prolonged to 2.4 hours. Coadministration of zolpidem with itraconazole or fluconazole also reduced clearance (320 and 338 mL/min), but differences compared to the zolpidem plus placebo treatment did not reach significance. Zolpidem-induced benzodiazepine agonist effects (increased electrocardiographic beta activity, digit-symbol substitution test impairment, and delayed recall) during the first 4 hours after dosage were enhanced by ketoconazole but not by itraconazole or fluconazole. CONCLUSION Coadministration of zolpidem with ketoconazole impairs zolpidem clearance and enhances its benzodiazepine-like agonist pharmacodynamic effects. Itraconazole and fluconazole had a small influence on zolpidem kinetics and dynamics. The findings are consistent with in vitro studies of differentially impaired zolpidem metabolism by azole derivatives.
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Affiliation(s)
- D J Greenblatt
- Department of Pharmacology, and Experimental Therapeutics, Tufts University School of Medicine, Boston, MA 02111, USA.
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Greenblatt DJ, Harmatz JS, von Moltke LL, Ehrenberg BL, Harrel L, Corbett K, Counihan M, Graf JA, Darwish M, Mertzanis P, Martin PT, Cevallos WH, Shader RI. Comparative kinetics and dynamics of zaleplon, zolpidem, and placebo. Clin Pharmacol Ther 1998; 64:553-61. [PMID: 9834048 DOI: 10.1016/s0009-9236(98)90139-4] [Citation(s) in RCA: 91] [Impact Index Per Article: 3.5] [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: 11/18/2022]
Abstract
PURPOSE This study evaluated the relationship of dose, plasma concentration, and time to the pharmacodynamics of zaleplon and zolpidem, 2 structurally distinct benzodiazepine receptor agonists. METHOD Ten healthy male volunteers received single oral doses of placebo, 10 mg zaleplon, 20 mg zaleplon, 10 mg zolpidem, and 20 mg zolpidem in a double-blind, 5-condition crossover study, with 48 hours elapsing between trials. Plasma drug concentrations and pharmacodynamic effects were measured during the 8 to 24 hours after administration. RESULTS Kinetics of zaleplon and zolpidem were not significantly related to dose. However, zaleplon had more rapid elimination (apparent elimination half-life [t1/2] of 1 hour) and higher apparent oral clearance (approximately 4300 mL/min) than zolpidem (t1/2, 2.0 to 2.2 hours; apparent oral clearance, 340 to 380 mL/min). Active treatments produced pharmacodynamic effects consistent with benzodiazepine agonist activity: self- and observer-rated sedation, impairment of digit symbol substitution test (DSST) performance, impaired memory, and increased electroencephalographic activity in the beta frequency range. The overall order of agonist potency was as follows: placebo < 10 mg zaleplon < 20 mg zaleplon < 10 mg zolpidem < 20 mg zolpidem; on a number of measures, 20 mg zaleplon was comparable to 10 mg zolpidem. Quantitative effects of zolpidem 20 mg far exceeded those of other treatments. Dynamic effects of both drugs were significantly related to plasma concentration. CONCLUSIONS Benzodiazepine agonist effects of zaleplon and zolpidem were dose and concentration dependent. At the usual clinically effective hypnotic dose (10 mg of either drug), agonist effects of zolpidem exceeded those of zaleplon.
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Affiliation(s)
- D J Greenblatt
- Department of Pharmacology and Experimental Therapeutics, Tufts University School of Medicine, New England Medical Center Hospital, Boston 02111, USA.
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Greenblatt DJ, von Moltke LL, Harmatz JS, Counihan M, Graf JA, Durol AL, Mertzanis P, Duan SX, Wright CE, Shader RI. Inhibition of triazolam clearance by macrolide antimicrobial agents: in vitro correlates and dynamic consequences. Clin Pharmacol Ther 1998; 64:278-85. [PMID: 9757151 DOI: 10.1016/s0009-9236(98)90176-x] [Citation(s) in RCA: 67] [Impact Index Per Article: 2.6] [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: 11/22/2022]
Abstract
BACKGROUND Macrolide antimicrobial agents may impair hepatic clearance of drugs metabolized by cytochrome P4503A isoforms. Potential interactions of triazolam, a substrate metabolized almost entirely by cytochrome P4503A in humans, with 3 commonly prescribed macrolides were identified using an in vitro metabolic model. The actual interactions, and their pharmacodynamic consequences, were verified in a controlled clinical study. METHODS In an in vitro model using human liver microsomes, 250 mumol/L triazolam was incubated with ascending concentrations (0 to 250 mumol/L of troleandomycin, azithromycin, erythromycin, and clarithromycin. In a randomized, double-blind, 5-trial clinical pharmacokinetic-pharmacodynamic study, 12 volunteers received 0.125 mg triazolam orally, together with placebo, azithromycin, erythromycin, or clarithromycin. In a fifth trial they received placebo plus placebo. RESULTS Mean 50% inhibitory concentrations versus 4-hydroxytriazolam formation in vitro were as follows: 3.3 mumol/L troleandomycin, 27.3 mumol/L erythromycin, 25.2 mumol/L clarithromycin, and greater than 250 mumol/L azithromycin. Apparent oral clearance of triazolam when given with placebo or azithromycin was nearly identical (413 and 416 mL/min), as were peak plasma concentrations (1.25 and 1.32 ng/mL) and elimination half-life (2.7 and 2.6 hours). Apparent oral clearance was significantly reduced (P < .05) during erythromycin and clarithromycin trials (146 and 95 mL/min). Peak plasma concentration was correspondingly increased, and elimination half-life was prolonged. The effects of triazolam on dynamic measures were nearly identical when triazolam was given with placebo or azithromycin, but benzodiazepine agonist effects were enhanced during erythromycin and clarithromycin trials. CONCLUSION The in vitro model identifies macrolides that may impair triazolam clearance. Anticipated interactions, and their pharmacodynamic consequences in volunteer subjects, were verified in vivo.
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Affiliation(s)
- D J Greenblatt
- Department of Pharmacology and Experimental Therapeutics, Tufts University School of Medicine, Boston, MA 02111, USA
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Wu GD, Graf JA, Zadina JE, Chang SL. The expression of interleukin-1-beta converting enzyme (ICE) in rat is decreased following chronic exposure to morphine. Adv Exp Med Biol 1998; 437:51-8. [PMID: 9666256 DOI: 10.1007/978-1-4615-5347-2_6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Affiliation(s)
- G D Wu
- Department of Biology, Seton Hall University, South Orange, New Jersey 07079, USA
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Graf JA, Patel JA, Chang SL. Chronic exposure to morphine, but not ethanol, attenuates the expression of interleukin-1 beta converting enzyme in rat spleen. Immunol Lett 1997; 58:153-7. [PMID: 9293396 DOI: 10.1016/s0165-2478(97)00042-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
IL-1 beta converting enzyme (ICE), a proteolytic enzyme that converts the inactive precursor of interleukin-1 beta (IL-1 beta) to its mature active form, has been abundantly detected in the IL-1 beta producing cells in the spleen. Since IL-1 beta is a potent neuro-endocrine-immuno modulator, alterations in the production of IL-1 beta by an exogenous factor, such as morphine or ethanol, may have deleterious effects on the system as a whole. In this study, we examined the expression of ICE in the spleens of rats given chronic treatment with morphine versus ethanol using reverse transcriptase-polymerase chain reaction (RT-PCR). The expression of ICE in the spleen of rats given chronic morphine was clearly less than that of the animals given placebo, however, it was similar for both rats on ethanol and control diets. These data suggest that chronic use of morphine, but not ethanol, attenuates the expression of ICE in the spleen.
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Affiliation(s)
- J A Graf
- Department of Biology, Seton Hall University, South Orange, NJ 07079, USA
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Morse RM, Norvich RC, Graf JA. Tobacco chewing an unusual case of drug dependence. Mayo Clin Proc 1977; 52:358-60. [PMID: 559223] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
This case report is that of a 53-year-old man without current evidence of significant psychiatric disorder who requested treatment for dependence on chewing-tobbaco. During his successful treatment in the Alcoholism and Drug Dependence Unit, we noted several similarities between his tobacco chewing and other drug dependencies.
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Graf JA, Smirnova GA, Zhdanov VM. Morphology of components of Sendai virus. Nature 1965; 207:323-4. [PMID: 4287383 DOI: 10.1038/207323a0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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