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  1. HPLC determination of imatinib in plasma and tissues after multiple oral dose administration to mice
    Teoh M, Narayanan P, Moo KS, Radhakrisman S, Pillappan R, Bukhari NI, et al.
    Pak J Pharm Sci, 2010 Jan;23(1):35-41.
    PMID: 20067864
    Imatinib inhibits Bcr-Abl, c-KIT and PDGFR kinases. It is approved for the treatment of chronic myeloid leukemia (CML), gastrointestinal stromal tumors (GIST) and has further therapeutic potential. Male ICR mice were given imatinib PO (50 or 25 mg/kg, 5 doses every 2 h); euthanized 2 h after the last dose administration; plasma, liver, brain, spleen and kidney were collected and imatinib concentration measured by an optimized HPLC method for quantification in tissues. Methanol (1:1 v/v plasma) and pH 4, 40:30:30 (v/v/v) water-methanol-acetonitrile at 5 ml/g (brain) and 10 ml/g (spleen, kidney, liver) ratio was added to the samples, homogenized, sonicated, centrifuged (15,000 rpm, 5 min, 2 degrees C) and the supernatant injected into an Inertsil CN-3 column (4.6 mm x 150 mm, 5 microm) using 64:35:1 (v/v/v) water-methanol-triethylamine (pH 4.8), flow rate 1 ml/min, 25 degrees C. Imatinib eluted at 7.5 min (268 nm). Linearity: 0.1-50 microg/ml; precision, accuracy, inter- and intra-day variability was within 15%. Recovery was above 95% (plasma), 80% (brain) and 90% (kidney, liver, spleen). Imatinib tissue concentrations were 6-8 folds higher than plasma except brain, where the ratio decreased from 0.24 to 0.08 suggesting limited brain penetration, likely due to blood brain barrier efflux transporters. The extensive distribution supports the expansion of therapeutic applications.
    Matched MeSH terms: Pyrimidines/administration & dosage
  2. Fulltext Cardiovascular event in chronic myeloid leukaemia treated with tyrosine kinase inhibitor: a case report
    Boo YL, Liam CCK, Lim SY, Look ML
    Hong Kong Med J, 2019 Feb;25(1):74-5.
    PMID: 30713145 DOI: 10.12809/hkmj176972
    Matched MeSH terms: Pyrimidines/administration & dosage
  3. Disposition and tissue distribution of imatinib in a liposome formulation after intravenous bolus dose to mice
    Moo KS, Radhakrishnan S, Teoh M, Narayanan P, Bukhari NI, Segarra I
    Yao Xue Xue Bao, 2010 Jul;45(7):901-8.
    PMID: 20931790
    Imatinib is an efficacious anticancer drug with a spectrum of potential antitumour applications limited by poor biodistribution at therapeutic concentrations to the tissues of interest. We assess the pharmacokinetic and tissue distribution profile of imatinib in a liposome formulation. Its single dose (6.25 mg x kg(-1)) in a liposome formulation was administered iv to male mice. Imatinib concentration was measured in plasma, spleen, liver, kidney and brain using a HPLC assay. Non-compartmental pharmacokinetic approach was used to assess the disposition parameters. The plasma disposition profile was biphasic with a plateau-like second phase. The AUC(0-->infinity) was 11.24 microg x h x mL(-1), the elimination rate constant (k(el)) was 0.348 h(-1) and the elimination half life (t(1/2)) was 2.0 h. The mean residence time (MRT) was 2.59 h, V(SS) was 1.44 L x kg(-1) and clearance was 0.56 L x h x kg(-1). Liver achieved the highest tissue exposure: CMAX = 18.72 microg x mL(-1); AUC(0-->infinity)= 58.18 microg x h x mL(-1) and longest t(1/2) (4.29 h) and MRT (5.31 h). Kidney and spleen AUC(0-->infinity) were 47.98 microg x h x mL(-1) and 23.46 microg x h x mL(-1), respectively. Half-life was 1.83 h for the kidney and 3.37 h for the spleen. Imatinib penetrated into the brain reaching approximately 1 microg x g(-1). Upon correction by organ blood flow the spleen showed the largest uptake efficiency. Liposomal imatinib presented extensive biodistribution. The drug uptake kinetics showed mechanism differences amongst the tissues. These findings encourage the development of novel imatinib formulations to treat other cancers.
    Matched MeSH terms: Pyrimidines/administration & dosage
  4. Recurrent Trichosporon asahii glossitis: a case report
    Shareef BT, Harun A, Roziawati Y, Bahari IS, Deris ZZ, Ravichandran M
    J Contemp Dent Pract, 2008;9(3):114-20.
    PMID: 18335127
    This case report aims at describing an infection of the tongue as a manifestation of a Trichosporon asahii infection, its association with bronchial asthma and steroid administration, and to present a review of the literature pertaining to its antifungal susceptibility profile.
    Matched MeSH terms: Pyrimidines/administration & dosage
  5. Fulltext HOXA4 gene promoter hypermethylation as an epigenetic mechanism mediating resistance to imatinib mesylate in chronic myeloid leukemia patients
    Elias MH, Baba AA, Husin A, Sulong S, Hassan R, Sim GA, et al.
    Biomed Res Int, 2013;2013:129715.
    PMID: 23484077 DOI: 10.1155/2013/129715
    Development of resistance to imatinib mesylate (IM) in chronic myeloid leukemia (CML) patients has emerged as a significant clinical problem. The observation that increased epigenetic silencing of potential tumor suppressor genes correlates with disease progression in some CML patients treated with IM suggests a relationship between epigenetic silencing and resistance development. We hypothesize that promoter hypermethylation of HOXA4 could be an epigenetic mechanism mediating IM resistance in CML patients. Thus a study was undertaken to investigate the promoter hypermethylation status of HOXA4 in CML patients on IM treatment and to determine its role in mediating resistance to IM. Genomic DNA was extracted from peripheral blood samples of 95 CML patients (38 good responders and 57 resistant) and 12 normal controls. All samples were bisulfite treated and analysed by methylation-specific high-resolution melt analysis. Compared to the good responders, the HOXA4 hypermethylation level was significantly higher (P = 0.002) in IM-resistant CML patients. On comparing the risk, HOXA4 hypermethylation was associated with a higher risk for IM resistance (OR 4.658; 95% CI, 1.673-12.971; P = 0.003). Thus, it is reasonable to suggest that promoter hypermethylation of HOXA4 gene could be an epigenetic mechanism mediating IM resistance in CML patients.
    Matched MeSH terms: Pyrimidines/administration & dosage*
  6. Fulltext Nilotinib dose-optimization in newly diagnosed chronic myeloid leukaemia in chronic phase: final results from ENESTxtnd
    Hughes TP, Munhoz E, Aurelio Salvino M, Ong TC, Elhaddad A, Shortt J, et al.
    Br J Haematol, 2017 10;179(2):219-228.
    PMID: 28699641 DOI: 10.1111/bjh.14829
    The Evaluating Nilotinib Efficacy and Safety in Clinical Trials-Extending Molecular Responses (ENESTxtnd) study was conducted to evaluate the kinetics of molecular response to nilotinib in patients with newly diagnosed chronic myeloid leukaemia in chronic phase and the impact of novel dose-optimization strategies on patient outcomes. The ENESTxtnd protocol allowed nilotinib dose escalation (from 300 to 400 mg twice daily) in the case of suboptimal response or treatment failure as well as dose re-escalation for patients with nilotinib dose reductions due to adverse events. Among 421 patients enrolled in ENESTxtnd, 70·8% (95% confidence interval, 66·2-75·1%) achieved major molecular response (BCR-ABL1 ≤ 0·1% on the International Scale) by 12 months (primary endpoint). By 24 months, 81·0% of patients achieved major molecular response, including 63·6% (56 of 88) of those with dose escalations for lack of efficacy and 74·3% (55 of 74) of those with dose reductions due to adverse events (including 43 of 54 patients with successful re-escalation). The safety profile of nilotinib was consistent with prior studies. The most common non-haematological adverse events were headache, rash, and nausea; cardiovascular events were reported in 4·5% of patients (grade 3/4, 3·1%). The study was registered at clinicaltrials.gov (NCT01254188).
    Matched MeSH terms: Pyrimidines/administration & dosage*
  7. Lack of hepato- and nephrotoxicity induced by antifungal drug voriconazole in laboratory rats
    Somchit N, Chung JH, Yaacob A, Ahmad Z, Zakaria ZA, Kadir AA
    Drug Chem Toxicol, 2012 Jul;35(3):304-9.
    PMID: 22288423 DOI: 10.3109/01480545.2011.614619
    Voriconazole is a new, potent broad-spectrum triazole systemic antifungal drug, a second-generation azole antifungal that is increasing in popularity, especially for the treatment of invasive aspergillosis and fluconazole-resistant invasive Candida infections. However, it is also known to induce hepatotoxicity clinically. The aim of this study was to investigate the hepatotoxicity and nephrotoxicity potential of voriconazole in vivo in rats. Forty rats were treated intraperitoneally with voriconazole as single (0, 10, l00, and 200 mg/kg) or repeated (0, 10, 50, and l00 mg/kg per day for 14 days) doses. Venous blood was collected for the repeated-dose group on days 1 and 14. Rats were sacrificed 24 hours after the last dose. Body weight, liver weight, and kidney weight of rats were recorded. Livers and kidneys samples were taken for histological and transmission electron microscopy (TEM) analysis. Results revealed that voriconazole had no effects on serum alanine aminotransferase, aspartate aminotransferase, alkaline phosphotase, gamma glutamyl transpeptidase, blood urea nitrogen, and creatinine for both the single- and repeated-dose groups. However, histologically, in the repeated 50- and 100-mg/kg voriconazole-treated rats, mild focal inflammation was observed. Under TEM, only small changes in the 100 mg/kg/day group were revealed. These results collectively demonstrated that voriconazole did not induce significant hepatotoxicity and nephrotoxicity, even at very high doses.
    Matched MeSH terms: Pyrimidines/administration & dosage
  8. Estrogen receptor (ER)-α, β and progesterone receptor (PR) mediates changes in relaxin receptor (RXFP1 and RXFP2) expression and passive range of motion of rats' knee
    Dehghan F, Yusof A, Muniandy S, Salleh N
    Environ Toxicol Pharmacol, 2015 Nov;40(3):785-91.
    PMID: 26447688 DOI: 10.1016/j.etap.2015.09.004
    The high risk of knee injuries in female may be associated with sex-steroid hormone fluctuations during the menstrual cycle by its effect on ligaments and tendons stiffness. This study examined changes in knee range of motion in presence of estrogen and progesterone and investigated the interaction of their antagonists to relaxin receptors.
    Matched MeSH terms: Pyrimidines/administration & dosage
  9. Fulltext Prospective observational study on Pazopanib in patients treated for advanced or metastatic renal cell carcinoma in countries in Asia Pacific, North Africa, and Middle East regions: PARACHUTE study
    Erman M, Biswas B, Danchaivijitr P, Chen L, Wong YF, Hashem T, et al.
    BMC Cancer, 2021 Sep 14;21(1):1021.
    PMID: 34521387 DOI: 10.1186/s12885-021-08738-z
    BACKGROUND: Clinical effectiveness and safety data of pazopanib in patients with advanced or mRCC in real-world setting from Asia Pacific, North Africa, and Middle East countries are lacking.

    METHODS: PARACHUTE is a phase IV, prospective, non-interventional, observational study. Primary endpoint was the proportion of patients remaining progression free at 12 months. Secondary endpoints were ORR, PFS, safety and tolerability, and relative dose intensity (RDI).

    RESULTS: Overall, 190 patients with a median age of 61 years (range: 22.0-96.0) were included. Most patients were Asian (70%), clear-cell type RCC was the most common (81%), with a favourable (9%), intermediate (47%), poor (10%), and unknown (34%) MSKCC risk score. At the end of the observational period, 78 patients completed the observational period and 112 discontinued the study; 60% of patients had the starting dose at 800 mg. Median RDI was 82%, with 52% of patients receiving  10%) TEAEs related to pazopanib included diarrhoea (30%), palmar-plantar erythrodysesthesia syndrome (15%), and hypertension (14%).

    CONCLUSIONS: Results of the PARACHUTE study support the use of pazopanib in patients with advanced or mRCC who are naive to VEGF-TKI therapy. The safety profile is consistent with that previously reported by pivotal and real-world evidence studies.

    Matched MeSH terms: Pyrimidines/administration & dosage
  10. Fulltext Transient prenatal ruxolitinib treatment suppresses astrogenesis during development and improves learning and memory in adult mice
    Lee HC, Hamzah H, Leong MP, Md Yusof H, Habib O, Zainal Abidin S, et al.
    Sci Rep, 2021 Feb 15;11(1):3847.
    PMID: 33589712 DOI: 10.1038/s41598-021-83222-z
    Ruxolitinib is the first janus kinase 1 (JAK1) and JAK2 inhibitor that was approved by the United States Food and Drug Administration (FDA) agency for the treatment of myeloproliferative neoplasms. The drug targets the JAK/STAT signalling pathway, which is critical in regulating the gliogenesis process during nervous system development. In the study, we assessed the effect of non-maternal toxic dosages of ruxolitinib (0-30 mg/kg/day between E7.5-E20.5) on the brain of the developing mouse embryos. While the pregnant mice did not show any apparent adverse effects, the Gfap protein marker for glial cells and S100β mRNA marker for astrocytes were reduced in the postnatal day (P) 1.5 pups' brains. Gfap expression and Gfap+ cells were also suppressed in the differentiating neurospheres culture treated with ruxolitinib. Compared to the control group, adult mice treated with ruxolitinib prenatally showed no changes in motor coordination, locomotor function, and recognition memory. However, increased explorative behaviour within an open field and improved spatial learning and long-term memory retention were observed in the treated group. We demonstrated transplacental effects of ruxolitinib on astrogenesis, suggesting the potential use of ruxolitinib to revert pathological conditions caused by gliogenic-shift in early brain development such as Down and Noonan syndromes.
    Matched MeSH terms: Pyrimidines/administration & dosage*
  11. Association of genotypes and haplotypes of multi-drug transporter genes ABCB1 and ABCG2 with clinical response to imatinib mesylate in chronic myeloid leukemia patients
    Au A, Aziz Baba A, Goh AS, Wahid Fadilah SA, Teh A, Rosline H, et al.
    Biomed Pharmacother, 2014 Apr;68(3):343-9.
    PMID: 24581936 DOI: 10.1016/j.biopha.2014.01.009
    The introduction and success of imatinib mesylate (IM) has become a paradigm shift in chronic myeloid leukemia (CML) treatment. However, the high efficacy of IM has been hampered by the issue of clinical resistance that might due to pharmacogenetic variability. In the current study, the contribution of three common single nucleotide polymorphisms (SNPs) of ABCB1 (T1236C, G2677T/A and C3435T) and two SNPs of ABCG2 (G34A and C421A) genes in mediating resistance and/or good response among 215 CML patients on IM therapy were investigated. Among these patients, the frequency distribution of ABCG2 421 CC, CA and AA genotypes were significantly different between IM good response and resistant groups (P=0.01). Resistance was significantly associated with patients who had homozygous ABCB1 1236 CC genotype with OR 2.79 (95%CI: 1.217-6.374, P=0.01). For ABCB1 G2677T/A polymorphism, a better complete cytogenetic remission was observed for patients with variant TT/AT/AA genotype, compared to other genotype groups (OR=0.48, 95%CI: 0.239-0.957, P=0.03). Haplotype analysis revealed that ABCB1 haplotypes (C1236G2677C3435) was statistically linked to higher risk to IM resistance (25.8% vs. 17.4%, P=0.04), while ABCG2 diplotype A34A421 was significantly correlated with IM good response (9.1% vs. 3.9%, P=0.03). In addition, genotypic variant in ABCG2 421C>A was associated with a major molecular response (MMR) (OR=2.20, 95%CI: 1.273-3.811, P=0.004), whereas ABCB1 2677G>T/A variant was associated with a significantly lower molecular response (OR=0.49, 95%CI: 0.248-0.974, P=0.04). However, there was no significant correlation of these SNPs with IM intolerance and IM induced hepatotoxicity. Our results suggest the usefulness of genotyping of these single nucleotide polymorphisms in predicting IM response among CML patients.
    Matched MeSH terms: Pyrimidines/administration & dosage
  12. Fulltext SLC22A1-ABCB1 haplotype profiles predict imatinib pharmacokinetics in Asian patients with chronic myeloid leukemia
    Singh O, Chan JY, Lin K, Heng CC, Chowbay B
    PLoS One, 2012;7(12):e51771.
    PMID: 23272163 DOI: 10.1371/journal.pone.0051771
    This study aimed to explore the influence of SLC22A1, PXR, ABCG2, ABCB1 and CYP3A5 3 genetic polymorphisms on imatinib mesylate (IM) pharmacokinetics in Asian patients with chronic myeloid leukemia (CML).
    Matched MeSH terms: Pyrimidines/administration & dosage
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