Abstract:
BACKGROUND:Thiopurine S-methyltransferase (TPMT) is an excellent example of an enzyme whose pharmacogenetic polymorphisms affect efficacy and toxicity of a drug. The association between TPMT activity and thiopurine-related myelosuppression is well recognized. To study the significance of TPMT deficiency in thiopurine metabolism and immunosuppressive activity in vitro, we established RNA interference-based TPMT knockdown (kd) in a Jurkat cell line. RESULTS:In Jurkat TPMT kd cells, TPMT expression was reduced to 73% at the RNA level and 83% at the protein level. TPMT kd cells were more sensitive to 6-mercaptopurine (6-MP) (10 μmol/L) and 6-thioguanine (6-TG) (8 μmol/L) than wild-type (wt) cells, (32% versus 20%) and (18% versus 9%), respectively. Both Jurkat wt and kd cells were more sensitive to 6-TG-induced apoptosis than to 6-MP. 6-TG activity was also more affected by TPMT levels than was 6-MP as reflected by IC60, concentrations that is, 6-MP [4.6 μmol/L (wt) and 4.7 μmol/L (kd)], 6-TG [2.7 μmol/L (wt) and 0.8 μmol/L (kd)]. IC60 concentrations induced significant apoptosis in both Jurkat wt and kd cells (257%, versus 314%) with 6-MP and (323% versus 306%) with 6-TG, respectively. At IC60 (6-MP) 6-thioguanine nucleotides (6-TGN) accumulation in cells was 518 versus 447 pmol/million cells in wt and kd cells, respectively. On the other hand 6-TGN accumulation at IC60 (6-TG) was 477 versus 570 pmol/million cells in wt and kd cells, respectively. 6-Methylated mercaptopurine (6-MeMP) concentrations were more affected than 6-TGN by TPMT kd (194 versus 10 pmol/million cells) in wt and kd cells, respectively. CONCLUSION:We conclude that TPMT kd cells are an appropriate in vitro model to investigate the significance of TPMT deficiency with thiopurine therapy and could be helpful in understanding possible clinical consequences of TPMT polymorphism.
journal_name
Ther Drug Monitjournal_title
Therapeutic drug monitoringauthors
Misdaq M,Andag R,Oellerich M,Asif AR,von Ahsen Ndoi
10.1097/FTD.0b013e31826ec4b4subject
Has Abstractpub_date
2012-10-01 00:00:00pages
584-92issue
5eissn
0163-4356issn
1536-3694pii
00007691-201210000-00016journal_volume
34pub_type
杂志文章abstract::Palivizumab is a humanized, monoclonal antibody used to protect at-risk infants against respiratory syncytial virus (RSV) infection. The regular dosage scheme causes a low initial trough level and accumulation of the antibody after subsequent injections. Using a simple pharmacokinetic model, the authors devised an alt...
journal_title:Therapeutic drug monitoring
pub_type: 杂志文章
doi:10.1097/00007691-200206000-00020
更新日期:2002-06-01 00:00:00
abstract::The monitoring of plasma olanzapine concentrations has been found to be an important and useful tool for optimizing psychiatric treatment. The present study investigated the effect that clinical factors, such as smoking and age, and functional polymorphisms of UGT1A4, CYP1A2, and CYP2D6 genes have on plasma olanzapine...
journal_title:Therapeutic drug monitoring
pub_type: 杂志文章
doi:10.1097/FTD.0b013e31816336fd
更新日期:2008-02-01 00:00:00
abstract::A method for the quantitative determination of the tricyclic antidepressant drug amitriptyline (AT) and its active major metabolite, nortriptyline (NT), in plasma is described. The method involves a three-step extraction procedure, no derivatization, and a rapid run on a gas--liquid chromatograph equipped with a nitro...
journal_title:Therapeutic drug monitoring
pub_type: 杂志文章
doi:10.1097/00007691-198212000-00006
更新日期:1982-01-01 00:00:00
abstract::Designer drugs of the methylenedioxyphenylalkylamine type are increasingly abused. Studies on their metabolism in humans are necessary to develop a reliable gas chromatography--mass spectrometry (GC-MS) screening procedure. Such a method must allow their detection in urine for drug testing in clinical and forensic tox...
journal_title:Therapeutic drug monitoring
pub_type: 杂志文章
doi:10.1097/00007691-199608000-00027
更新日期:1996-08-01 00:00:00
abstract:BACKGROUND:Drug blood levels can only serve as a surrogate because of the lack of information on the drug's direct pharmacological effects in the individual patient. Measurement of the mammalian target of rapamycin (mTOR) activity dependent on the phosphorylation status of p70 S6 kinase (p70 S6K) offers a practical way...
journal_title:Therapeutic drug monitoring
pub_type: 杂志文章
doi:10.1097/FTD.0b013e3182804c9b
更新日期:2013-04-01 00:00:00
abstract::Exposure to mycophenolic acid (MPA) is highly variable among patients on standard dose mycophenolate mofetil (MMF) therapy. In addition, MPA exposure increases with time posttransplant and exposure is predictive for the development of acute rejection. Consequently, therapeutic drug monitoring (TDM) of MPA may improve ...
journal_title:Therapeutic drug monitoring
pub_type: 杂志文章,评审
doi:10.1097/01.ftd.0000194504.62892.b2
更新日期:2006-02-01 00:00:00
abstract::We describe the case of a pediatric patient on azathioprine therapy with previously undiagnosed homozygote thiopurine S-methyltransferase (TPMT) deficiency, resulting in myelotoxic thiopurine metabolite levels. The patient was successfully treated with a very low azathioprine dose of 50 mg once a week (4% of standard ...
journal_title:Therapeutic drug monitoring
pub_type: 杂志文章
doi:10.1097/FTD.0000000000000366
更新日期:2017-02-01 00:00:00
abstract::The interaction between valproic acid (VPA) and phenytoin (DPH) was examined during therapeutic monitoring in an epileptic outpatient population. Gas-liquid chromatographic methods were used to measure DPH and VPA concentrations. (1) In 12 patients on stable DPH regimens, the mean DPH level declined from 19.7 to 15.3 ...
journal_title:Therapeutic drug monitoring
pub_type: 杂志文章
doi:10.1097/00007691-197901020-00005
更新日期:1979-01-01 00:00:00
abstract::Hydroxylation of midazolam (MDZ) is mediated almost exclusively by CYP3A isoforms. The authors describe a high-performance liquid chromatography assay involving MDZ, 1'-hydroxymidazolam, and 4-hydroxymidazolam in plasma. The compounds were eluted on an Ultrasphere ODS, 3-microm particle size, 7.5 cm x 4.6 mm reversed-...
journal_title:Therapeutic drug monitoring
pub_type: 杂志文章
doi:10.1097/00007691-199806000-00013
更新日期:1998-06-01 00:00:00
abstract::Recent literature has urged caution in the interpretation of vancomycin serum concentrations in patients with end-stage renal disease (ESRD), because falsely elevated levels in excess of 70% have been reported with the most commonly used fluorescence polarization immunoassay (FPIA). The purpose of this study was to ev...
journal_title:Therapeutic drug monitoring
pub_type: 杂志文章
doi:10.1097/00007691-199804000-00016
更新日期:1998-04-01 00:00:00
abstract::A study was conducted to determine whether assay-specific quantitative differences exist in the determination of vancomycin serum concentrations obtained from patients with renal dysfunction. Vancomycin serum concentrations were obtained during the first week of therapy for each of three time intervals: 48-96 h, 96-14...
journal_title:Therapeutic drug monitoring
pub_type: 临床试验,杂志文章
doi:10.1097/00007691-199612000-00004
更新日期:1996-12-01 00:00:00
abstract::Drug discovery programs are actively exploring for therapeutic agents targeting enzymes and receptors regulating sphingolipid metabolism and biologic functions. FTY720 is a close structural analogue of sphingosine with immunomodulatory properties. After oral administration, FTY720 is phosphorylated by sphingosine kina...
journal_title:Therapeutic drug monitoring
pub_type: 杂志文章,评审
doi:10.1097/00007691-200412000-00001
更新日期:2004-12-01 00:00:00
abstract::The binding characteristics of the antiepileptic agent and teratogen valproic acid for human serum and human placenta were investigated utilizing equilibrium dialysis of the drugs in serum and in homogenates of whole placenta so that the transplacental transfer of the drug could be better defined. A low-capacity, high...
journal_title:Therapeutic drug monitoring
pub_type: 杂志文章
doi:10.1097/01.ftd.0000158077.07836.9a
更新日期:2005-06-01 00:00:00
abstract::The emergence of point-of-care assays enabling bedside testing such as the VerifyNow P2Y12 system might prove useful in clinical settings. The aim of this study was to evaluate the ability of the VerifyNow P2Y12 assay to estimate the inhibition of platelet aggregation provided by clopidogrel in the absence of baseline...
journal_title:Therapeutic drug monitoring
pub_type: 杂志文章,随机对照试验
doi:10.1097/FTD.0b013e3181757c59
更新日期:2008-06-01 00:00:00
abstract::Sotrastaurin (AEB071) is an investigational immunosuppressant that blocks T-lymphocyte activation through protein kinase C inhibition. It is currently in Phase II of clinical development for the prevention of acute rejection after solid organ transplantation. In renal transplant clinical trials, sotrastaurin has been ...
journal_title:Therapeutic drug monitoring
pub_type: 杂志文章,评审
doi:10.1097/FTD.0b013e3181ee9e26
更新日期:2010-10-01 00:00:00
abstract::Whole blood steady-state trough concentrations of cyclosporine were measured by radioimmunoassay (RIA) and TDx assays employing monoclonal antibodies in 82 samples from 39 renal transplant patients. Intra- and interassay coefficients of variation for the new TDx technique averaged 3.2 and 5.4%, respectively. In the co...
journal_title:Therapeutic drug monitoring
pub_type: 杂志文章
doi:10.1097/00007691-199109000-00012
更新日期:1991-09-01 00:00:00
abstract::An accurate and specific liquid chromatographic method for the separation and analysis of the R(+) and S(-) enantiomers of both aminoglutethimide (AG) and its acetylated metabolite (AcAG) in plasma, saliva, and urine is described. The separation was achieved by use of two serial Chiralcel OD columns [cellulose tris(3,...
journal_title:Therapeutic drug monitoring
pub_type: 杂志文章
doi:10.1097/00007691-199510000-00017
更新日期:1995-10-01 00:00:00
abstract:BACKGROUND:Despite significant interindividual variability in prednisolone pharmacokinetics and potentially serious consequences with inadequate or excessive exposure, monitoring of prednisolone levels is not employed to guide therapy. As ultrahigh-performance liquid chromatography-tandem mass spectrometry methods can ...
journal_title:Therapeutic drug monitoring
pub_type: 杂志文章
doi:10.1097/FTD.0b013e31829daae4
更新日期:2014-02-01 00:00:00
abstract:BACKGROUND:Posaconazole is an azole antifungal agent with a broad spectrum of activity and a manageable side-effect profile. Although the pharmacokinetics of posaconazole have been described in healthy volunteers who received the drug by means of a nasogastric tube or with nutritional supplements, the pharmacokinetics ...
journal_title:Therapeutic drug monitoring
pub_type: 杂志文章,随机对照试验
doi:10.1097/FTD.0b013e31821fb197
更新日期:2011-08-01 00:00:00
abstract::A rapid and simultaneous determination of several analgesic antiinflammatory agents--ibuprofen, acetaminophen, indomethacin, and salicylic acid--in human serum was developed by using capillary zone electrophoresis (CZE) coupled with diode-array ultraviolet detection. After precipitation of serum protein with acetonitr...
journal_title:Therapeutic drug monitoring
pub_type: 杂志文章
doi:10.1097/00007691-200310000-00006
更新日期:2003-10-01 00:00:00
abstract::Fluorescence polarization immunoassay (FPIA) (TDx, Abbott Laboratories Diagnostics, Irvin, TX, U.S.A.) is commonly utilized for quantitative determination of gentamicin serum concentrations. Recently, automated homogeneous latex agglutination (LA) (Technicon Immuno-1, Miles Diagnostics Division, Tarrytown, NY, U.S.A.)...
journal_title:Therapeutic drug monitoring
pub_type: 杂志文章
doi:10.1097/00007691-199408000-00010
更新日期:1994-08-01 00:00:00
abstract::The study assessed the removal of mycophenolic acid (MPA) and its major glucuronide metabolite (MPAG) during continuous venovenous hemofiltration (CVVHF) and continuous venovenous hemodiafiltration (CVVHDF) in 4 heart transplant recipients treated for at least 6 days with mycophenolate mofetil (MMF) in addition to cyc...
journal_title:Therapeutic drug monitoring
pub_type: 杂志文章
doi:10.1097/FTD.0b013e3181633667
更新日期:2008-02-01 00:00:00
abstract::Pharmacokinetic and pharmacodynamic interactions between the gastrokinetic drug cisapride and the antipsychotic drugs bromperidol and haloperidol were studied in 29 schizophrenic inpatients. Fourteen patients were taking bromperidol (12-24 mg/d), and 15 were taking haloperidol (12-36 mg/d). Cisapride 10 mg/d was coadm...
journal_title:Therapeutic drug monitoring
pub_type: 临床试验,杂志文章
doi:10.1097/00007691-199906000-00007
更新日期:1999-06-01 00:00:00
abstract::Several studies have reported that the cytochrome P450 (CYP) 2D6 plays an important role in the fluvoxamine metabolism. However, some other studies have reported that the CYP2D6 genotype has no major impact on the fluvoxamine concentration. This study investigated the dose-dependent effect of CYP2D6-variant alleles on...
journal_title:Therapeutic drug monitoring
pub_type: 杂志文章
doi:10.1097/FTD.0b013e31818d73b3
更新日期:2008-12-01 00:00:00
abstract::Steady-state serum concentrations of quetiapine were recorded in 62 psychiatric patients under routine conditions. Doses were administered twice daily, and serum quetiapine levels were measured in the morning about 12 hours after the last dose. Eight patients were in monotherapy, whereas the rest received various addi...
journal_title:Therapeutic drug monitoring
pub_type: 临床试验,杂志文章
doi:10.1097/00007691-200410000-00005
更新日期:2004-10-01 00:00:00
abstract::An analytical technique using liquid chromatography (LC) coupled with electrospray-mass spectrometry (ESI--MS) has been developed for the simultaneous determination of five protease inhibitors (PIs): saquinavir, indinavir, ritonavir, nelfinavir, and amprenavir; and three non-nucleoside reverse transcriptase inhibitors...
journal_title:Therapeutic drug monitoring
pub_type: 杂志文章
doi:10.1097/00007691-200108000-00010
更新日期:2001-08-01 00:00:00
abstract:PURPOSE:Substance use disorder often coexists with other psychiatric disorders, resulting in the simultaneous use of recreational and prescription drugs. The authors aimed to identify potential pharmacokinetic and pharmacodynamic interactions between new psychoactive substances of the cathinone class and specific presc...
journal_title:Therapeutic drug monitoring
pub_type: 杂志文章
doi:10.1097/FTD.0000000000000682
更新日期:2020-02-01 00:00:00
abstract:OBJECTIVES:The objective of the present study was to perform an external evaluation of published linezolid population pharmacokinetic and pharmacodynamic models, in order to evaluate the predictive performance using an independent dataset. Another aim was to offer an elegant environment for display and simulation of bo...
journal_title:Therapeutic drug monitoring
pub_type: 杂志文章
doi:10.1097/FTD.0000000000000816
更新日期:2020-09-28 00:00:00
abstract::The clinical correlates of methylphenidate blood levels in hyper-active children and normal adults were examined in five studies. Although occasional correlations between blood levels and neuroendocrine response were noted within subjects along the pharmacokinetic time profile of the drug, no significant associations ...
journal_title:Therapeutic drug monitoring
pub_type: 杂志文章
doi:10.1097/00007691-198412000-00001
更新日期:1984-01-01 00:00:00
abstract::The diurnal fluctuations in free and total plasma levels of carbamazepine (CBZ) and carbamazepine-10,11-epoxide (CBZ-E) and their relationship with intermittent side effects were examined in 10 epileptic patients stabilized on chronic CBZ therapy alone or in combination with phenobarbital (PB). With a t.i.d. or q.i.d....
journal_title:Therapeutic drug monitoring
pub_type: 杂志文章
doi:10.1097/00007691-198412000-00005
更新日期:1984-01-01 00:00:00