Displaying publications 1 - 20 of 86 in total

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  1. Wilson T, Edeson JF
    Br Med J, 1953;1:253-5.
    Matched MeSH terms: Pyrimidines
  2. Abdullah Z, Tahir NM, Abas MR, Aiyub Z, Low BK
    Molecules, 2004 Jun 30;9(7):520-6.
    PMID: 18007451
    The reactions of 2-chloropyrimidine with methylamine, ethylamine and piperidine gave the corresponding 2-N-methylamino-, 2-N-ethylamino- and 2N- piperidinopyrimidines, respectively. The fluorescence properties of these alkylamino derivatives in chloroform, ethyl acetate, carbon tetrachloride, acetone, ether, ethanol and methanol were studied. All the alkylamino derivatives showed the highest fluorescence intensity in polar protic solvents; thus 2-N-methylaminopyrimidine (highest fluorescence intensity at 377 nm when excited at 282 nm) and 2-N-ethylaminopyrimidine (highest fluorescence intensity at 375 nm, when excited at 286 nm) showed the highest fluorescence in methanol. In ethanol, 2-N-piperidinopyrimidine showed a fluorescence peak at 403 nm when excited at 360 nm and in chloroform it fluoresced at 392 nm when excited at 356 nm.
    Matched MeSH terms: Pyrimidines/chemistry*
  3. Kow CS, Ramachandram DS, Hasan SS
    Angiogenesis, 2023 Nov;26(4):481-483.
    PMID: 37530975 DOI: 10.1007/s10456-023-09889-2
    Imatinib, an ABL tyrosine-kinase inhibitor, shows promise in restoring endothelial barrier function in patients with COVID-19, thus, preventing cytokine leakage from the alveolar compartment to the systemic compartment. COVID-19 is characterized by an alveolar cytokine storm, and imatinib has been shown to strengthen the endothelial barrier and mitigate alveolar inflammatory responses by modulating NF-κB signaling. Incorporating imatinib into COVID-19 treatment strategies offers a novel approach to safeguard the endothelial barrier and address the complex pathophysiology of the disease, including its potential implications in long COVID. Given that endothelial dysfunction plays a central role in COVID-19 progression and long COVID development, protecting the endothelial barrier during acute infection is crucial in preventing the persistent endothelial dysfunction associated with long COVID.
    Matched MeSH terms: Pyrimidines/pharmacology; Pyrimidines/therapeutic use
  4. Yam SC, Zain SM, Sanghiran Lee V, Chew KH
    Eur Phys J E Soft Matter, 2018 Jul 18;41(7):86.
    PMID: 30014219 DOI: 10.1140/epje/i2018-11696-5
    We have performed computational molecular modelling to study the polarization switching and hysteresis loop behaviours of DNA and RNA nucleobases using the PM3 semi-empirical quantum mechanical approaches. All the nucleobases: adenine (A), thymine (T), guanine (G), cytosine (C), and uracil (U) were modelled. Our study indicates that all the nucleobases exhibit a zero-field polarization due to the presence of polar atoms or molecules such as amidogen and carbonyl. The shape of polarization P versus an applied electric field E hysteresis loop is square, implying typical ferroelectrics behaviour. The total energy U as a function of an applied electric field E exhibits a butterfly-like loop. The presence of zero-field polarization and ferroelectrics hysteresis loop behaviours in nucleobases may support the hypothesis of the existence of bioferroelectricity in DNA and RNA. We also found an interesting relationship between the minimum electric field required for switching [Formula: see text] and the ratio of the topological polar surface area (TPSA) to the total surface area (TSA) of a nucleobase. In particular, the [Formula: see text] of a nucleobase is inversely proportional to the TPSA/TSA ratio. This work may provide useful information for understanding the possible existence of ferroelectricity in biomaterials.
    Matched MeSH terms: Pyrimidines/chemistry*
  5. Mpofu E, Alias A, Tomita K, Suzuki-Minakuchi C, Tomita K, Chakraborty J, et al.
    Chemosphere, 2021 Jun;273:129663.
    PMID: 33515965 DOI: 10.1016/j.chemosphere.2021.129663
    Azoxystrobin (AZ) is a broad-spectrum synthetic fungicide widely used in agriculture globally. However, there are concerns about its fate and effects in the environment. It is reportedly transformed into azoxystrobin acid as a major metabolite by environmental microorganisms. Bacillus licheniformis strain TAB7 is used as a compost deodorant in commercial compost and has been found to degrade some phenolic and agrochemicals compounds. In this article, we report its ability to degrade azoxystrobin by novel degradation pathway. Biotransformation analysis followed by identification by electrospray ionization-mass spectrometry (MS), high-resolution MS, and nuclear magnetic resonance spectroscopy identified methyl (E)-3-amino-2-(2-((6-(2-cyanophenoxy)pyrimidin-4-yl)oxy)phenyl)acrylate, or (E)-azoxystrobin amine in short, and (Z) isomers of AZ and azoxystrobin amine as the metabolites of (E)-AZ by TAB7. Bioassay testing using Magnaporthe oryzae showed that although 40 μg/mL of (E)-AZ inhibited 59.5 ± 3.5% of the electron transfer activity between mitochondrial Complexes I and III in M. oryzae, the same concentration of (E)-azoxystrobin amine inhibited only 36.7 ± 15.1% of the activity, and a concentration of 80 μg/mL was needed for an inhibition rate of 56.8 ± 7.4%, suggesting that (E)-azoxystrobin amine is less toxic than the parent compound. To our knowledge, this is the first study identifying azoxystrobin amine as a less-toxic metabolite from bacterial AZ degradation and reporting on the enzymatic isomerization of (E)-AZ to (Z)-AZ, to some extent, by TAB7. Although the fate of AZ in the soil microcosm supplemented with TAB7 will be needed, our findings broaden our knowledge of possible AZ biotransformation products.
    Matched MeSH terms: Pyrimidines
  6. Wu YL, Guarneri V, Voon PJ, Lim BK, Yang JJ, Wislez M, et al.
    Lancet Oncol, 2024 Aug;25(8):989-1002.
    PMID: 39089305 DOI: 10.1016/S1470-2045(24)00270-5
    BACKGROUND: Patients with EGFR-mutated non-small-cell lung cancer (NSCLC) and MET amplification as a mechanism of resistance to first-line osimertinib have few treatment options. Here, we report the primary analysis of the phase 2 INSIGHT 2 study evaluating tepotinib, a highly selective MET inhibitor, combined with osimertinib in this population.

    METHODS: This open-label, phase 2 study was conducted at 179 academic centres and community clinics in 17 countries. Eligible patients were aged 18 years or older with an Eastern Cooperative Oncology Group performance status of 0 or 1 and advanced or metastatic EGFR-mutated NSCLC of any histology, with MET amplification by tissue biopsy fluorescence in-situ hybridisation (FISH; MET gene copy number of ≥5 or MET-to-CEP7 ratio of ≥2) or liquid biopsy next-generation sequencing (MET plasma gene copy number of ≥2·3), following progression on first-line osimertinib. Patients received oral tepotinib 500 mg plus oral osimertinib 80 mg once daily. The primary endpoint was independently assessed objective response in patients with MET amplification by central FISH treated with tepotinib plus osimertinib with at least 9 months of follow-up. Safety was analysed in patients who received at least one study drug dose. This study is registered with ClinicalTrials.gov, NCT03940703 (enrolment complete).

    FINDINGS: Between Feb 13, 2020, and Nov 4, 2022, 128 patients (74 [58%] female, 54 [42%] male) were enrolled and initiated tepotinib plus osimertinib. The primary activity analysis population included 98 patients with MET amplification confirmed by central FISH, previous first-line osimertinib and at least 9 months of follow-up (median 12·7 months [IQR 9·9-20·3]). The confirmed objective response rate was 50·0% (95% CI 39·7-60·3; 49 of 98 patients). The most common treatment-related grade 3 or worse adverse events were peripheral oedema (six [5%] of 128 patients), decreased appetite (five [4%]), prolonged electrocardiogram QT interval (five [4%]), and pneumonitis (four [3%]). Serious treatment-related adverse events were reported in 16 (13%) patients. Deaths of four (3%) patients were assessed as potentially related to either trial drug by the investigator due to pneumonitis (two [2%] patients), decreased platelet count (one [1%]), respiratory failure (one [1%]), and dyspnoea (one [1%]); one death was attributed to both pneumonitis and dyspnoea.

    INTERPRETATION: Tepotinib plus osimertinib showed promising activity and acceptable safety in patients with EGFR-mutated NSCLC and MET amplification as a mechanism of resistance to first-line osimertinib, suggesting a potential chemotherapy-sparing oral targeted therapy option that should be further investigated.

    FUNDING: Merck (CrossRef Funder ID: 10.13039/100009945).

    Matched MeSH terms: Pyrimidines/administration & dosage; Pyrimidines/adverse effects; Pyrimidines/therapeutic use
  7. Chellappan DK, Chellian J, Ng ZY, Sim YJ, Theng CW, Ling J, et al.
    Biomed Pharmacother, 2017 Dec;96:768-781.
    PMID: 29054093 DOI: 10.1016/j.biopha.2017.10.058
    Pazopanib is a relatively new compound to be introduced into the chemotherapy field. It is thought to have decent anti-angiogenic properties, which gives an additional hope for the treatment of certain types of cancers. A systematic review solely discussing about pazopanib and its anti-angiogenic effect is yet to be published to date, despite several relevant clinical trials being conducted over the recent years. In this review, we aim to investigate the mechanism of pazopanib's anti-angiogenic effect and its effectiveness in treating several cancers. We have included, in this study, findings from electronically searchable data from randomized clinical trials, clinical studies, cohort studies and other relevant articles. A total of 352 studies were included in this review. From the studies, the effect of pazopanib in various cancers or models was observed and recorded. Study quality is indefinite, with a few decent quality articles. The most elaborately studied cancers include renal cell carcinoma, solid tumors, advanced solid tumors, soft tissue sarcoma, breast cancer and gynecological cancers. In addition, several less commonly studied cancers are included in the studies as well. Pazopanib had demonstrated its anti-angiogenic effect based on favorable results observed in cancers, which are caused by angiogenesis-related mechanisms, such as renal cell carcinoma, solid tumors, advanced solid tumors and soft tissue sarcoma. This review was conducted to study, analyze and review the anti-angiogenic properties of pazopanib in various cancers. The results obtained can provide a decent reference when considering treatment options for angiogenesis-related malignancies. Furthermore, the definite observations of the anti-angiogenic effects of pazopanib could provide newer insights leading to the future development of drugs of the same mechanism with increased efficiency and reduced adverse effects.
    Matched MeSH terms: Pyrimidines/therapeutic use*
  8. Gajjala RR, Chinta RR, Gopireddy VSR, Poola S, Balam SK, Chintha V, et al.
    Bioorg Chem, 2022 Dec;129:106205.
    PMID: 36265354 DOI: 10.1016/j.bioorg.2022.106205
    Novel ethyl-4-(aryl)-6-methyl-2-(oxo/thio)-3,4-dihydro-1H-pyrimidine-5-carboxylates were synthesized from one-pot, three-component Biginelli reaction of aryl aldehydes, ethyl acetoacetate and urea/ thiourea by catalytic action of silica supported Bismuth(III) triflate, a Lewis acid. All the synthesized compounds were structurally characterized by spectral (IR, 1H NMR & 13C NMR spectroscopic and Mass spectrometric) and elemental (C, H & N) analyses. The present protocol has deserved novel as, formed the products in high yields with short reaction times, involved eco-friendly methodology and reusable heterogeneous Lewis acid catalyst. The title compounds were screened for in vitro DPPH free radical scavenging antioxidant activity and identified 4i, 4j, 4h & 4f as potential antioxidants. The obtained in vitro results were correlated with molecular docking, ADMET, QSAR, Bioactivity & toxicity risk studies and molecular finger print properties and found that in silico binding affinities were identified in good correlation with in vitro antioxidant activity and studied the structure activity relationship. The molecular docking study has disclosed strong hydrogen bonding interactions of title compounds with aspartic acid (ASP197) aminoacid residue of 2HCK, a complex enzyme of haematopoietic cell kinase and quercetin. Results of toxicology study evaluated for potential risks of compounds have revealed title compounds as safer drugs. In ultimate the study has established ligand's antioxidant potentiality as they effectively binds with ASP197 amino acid of Chain A hence confirms the inhibition of growth of reactive oxygen species in vivo. In addition, the title compounds have been identified as potential blood-brain barrier penetrable entities and efficient central nervous system (CNS) active neuro-protective antioxidant agents.
    Matched MeSH terms: Pyrimidines/chemistry
  9. Deif MA, Hafez MA, Khishe M, Solyman A, Elhaty IAM
    PLoS One, 2026;21(10):e0353101.
    PMID: 42945269 DOI: 10.1371/journal.pone.0353101
    Computational prediction of ABL1 tyrosine-kinase inhibitor (TKI) resistance is difficult because available mutation-drug datasets are small, imbalanced, and heterogeneous. This study evaluates structure-aware resistance prediction under mutation-disjoint internal validation and temporal cross-study outcome validation. The development benchmark comprised 144 ABL1 mutation-TKI records (19 resistant and 125 susceptible) labelled by a ten-fold affinity-loss criterion. A fixed panel of 11 documented structural and energetic predictors was used to minimize data-adaptive feature selection within the validation framework. A calibrated ensemble combining Elastic-Net logistic regression, radial-basis-function support-vector machines, random forests, and XGBoost was evaluated using mutation-disjoint five-fold grouped out-of-fold prediction repeated ten times. Temporal validation used a later prime-editing resistance map, yielding 84 exact mutation-TKI matches across imatinib, nilotinib, bosutinib, and ponatinib; 61 had binary Sensitive/Resistant outcomes and 23 were retained as Intermediate. The 11-feature stack achieved grouped internal AUROC 0.645 (95% CI 0.429-0.830) and PR-AUC 0.230, with mean ± SD AUROC 0.583 ± 0.101 across repeated grouped splits. On the 61 binary later-study outcomes, AUROC was 0.605 (95% CI 0.431-0.874) and PR-AUC 0.835, modestly above the resistance-prevalence baseline of 0.770. External calibration was poor (Brier score 0.583; calibration slope 0.441). Elastic-Net showed somewhat higher temporal discrimination (AUROC 0.643; PR-AUC 0.877). These results indicate limited transportability across mutation identities and experimental platforms and support use of the framework for hypothesis-generating resistance screening rather than clinically calibrated treatment selection.
    Matched MeSH terms: Pyrimidines/pharmacology
  10. Iftikhar F, Ali Y, Ahmad Kiani F, Fahad Hassan S, Fatima T, Khan A, et al.
    Bioorg Chem, 2017 10;74:53-65.
    PMID: 28753459 DOI: 10.1016/j.bioorg.2017.07.003
    In our previous report, we have identified 3,4-dihydropyrimidine scaffold as promising class of urease inhibitor in a structure based virtual screen (SBVS) experiment. In present study, we attempted to optimize the scaffold by varying C-5 substituent. The elongation of the C-5 chain was achieved by the reaction of C-5 ester with hydrazine leading to C-5 carbohydrazides which were further used as building blocks for the synthesis of fifteen new compounds having diverse moieties. A significantly higher in vitro urease inhibitory activity with IC50 values in submicromolar range was observed for semithiocarbazide derivatives (4a-c, 0.58-0.79µM) and isatin Schiff base derivative 5a (0.23µM). Docking analysis suggests that the synthesized compounds were anchored well in the catalytic site and extending to the entrance of binding pocket and thus restrict the mobility of the flap by interacting with its key amino acid residues. The overall results of urease inhibition have shown that these compounds can be further optimized and developed as lead urease inhibitors.
    Matched MeSH terms: Pyrimidines/chemical synthesis; Pyrimidines/pharmacology*; Pyrimidines/chemistry
  11. Jeevaraj M, Sivajeyanthi P, Edison B, Thanigaimani K, Balasubramani K, Razak IA
    Acta Crystallogr E Crystallogr Commun, 2017 Oct 01;73(Pt 10):1595-1598.
    PMID: 29250389 DOI: 10.1107/S2056989017013950
    In the title mol-ecular salt, 2C6H10N3O+·C8H4O42-, the N atom of each of the two 2-amino-4-meth-oxy-6-methyl-pyrimidine mol-ecules lying between the amine and methyl groups has been protonated. The dihedral angles between the pyrimidine rings of the cations and the benzene ring of the succinate dianion are 5.04 (8) and 7.95 (8)°. Each of the cations is linked to the anion through a pair of N-H⋯O(carboxyl-ate) hydrogen bonds, forming cyclic R22(8) ring motifs which are then linked through inversion-related N-H⋯O hydrogen bonds, giving a central R24(8) motif. Peripheral amine N-H⋯O hydrogen-bonding inter-actions on either side of the succinate anion, also through centrosymmetric R22(8) extensions, form one-dimensional ribbons extending along [211]. The crystal structure also features π-π stacking inter-actions between the aromatic rings of the pyrimidine cations [minimum ring centroid separation = 3.6337 (9) Å]. The inter-molecular inter-actions were also investigated using Hirshfeld surface studies and two-dimensional fingerprint images.
    Matched MeSH terms: Pyrimidines
  12. Bukhari SN, Butt AM, Amjad MW, Ahmad W, Shah VH, Trivedi AR
    Pak J Biol Sci, 2013 Nov 01;16(21):1368-72.
    PMID: 24511749
    Hypertension is a widespread and frequently progressive ailment that imparts a foremost threat for cardiovascular and renal disorders. Mammoth efforts are needed for the synthesis of innovative antihypertensive agents to combat this lethal disease. Chalcones have shown antihypertensive activity through inhibition of Angiotensin Converting Enzyme (ACE). Hence, a series of chalcone analogues is synthesized and used as precursor for the synthesis of novel series of pyrimidines. Precursor chalcones were prepared by reacting aldehydes and ketones in presence of sodium hydroxide followed by synthesis of corresponding pyrimidines by reaction with urea in presence of potassium hydroxide. Both groups were then evaluated for their effects on ACE. The results depicted that pyrimidines were more active than chalcones with methoxy (C5 and P5) substitution showing best results to inhibit ACE. Given that chalcone analogues and pyrimidines show a potential as the angiotensin converting enzyme inhibitors.
    Matched MeSH terms: Pyrimidines/chemical synthesis; Pyrimidines/pharmacology*; Pyrimidines/chemistry*
  13. Basiri A, Murugaiyah V, Osman H, Kumar RS, Kia Y, Hooda A, et al.
    Bioorg Med Chem, 2014 Jan 15;22(2):906-16.
    PMID: 24369842 DOI: 10.1016/j.bmc.2013.11.020
    Novel thiazolopyrimidine derivatives have been synthesized via microwave assisted, domino cascade methodology in ionic liquid and evaluated in vitro for their acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitory activities. Among the newly synthesized compounds 6d, 6a, 6e and 6b displayed higher AChE inhibitory activity than standard drug, galanthamine, with IC50 values of 0.53, 1.47, 1.62 and 2.05μM, respectively. Interestingly, all the compounds except for 6m-r and 6x displayed higher BChE inhibitory potentials than galanthamine with IC50 values ranging from 1.09 to 18.56μM. Molecular docking simulations for 6d possessing the most potent AChE and BChE inhibitory activities, disclosed its binding interactions at the active site gorge of AChE and BChE enzymes.
    Matched MeSH terms: Pyrimidines/chemical synthesis; Pyrimidines/pharmacology*; Pyrimidines/chemistry
  14. Basiri A, Murugaiyah V, Osman H, Kumar RS, Kia Y, Ali MA
    Bioorg Med Chem, 2013 Jun 1;21(11):3022-31.
    PMID: 23602518 DOI: 10.1016/j.bmc.2013.03.058
    A series of hitherto unreported pyrido-pyrimidine-2-ones/pyrimidine-2-thiones were synthesized under microwave assisted solvent free reaction conditions in excellent yields and evaluated in vitro for their acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) enzymes inhibitory activity. Among the pyridopyrimidine derivatives, 7e and 7l displayed 2.5- and 1.5-fold higher enzyme inhibitory activities against AChE as compared to standard drug, galanthamine, with IC50 of 0.80 and 1.37 μM, respectively. Interestingly, all the compounds except 6k, 7j and 7k displayed higher inhibitory potential against BChE enzyme in comparison to standard with IC50 ranging from 1.18 to 18.90 μM. Molecular modeling simulations of 7e and 7l was performed using three-dimensional structure of Torpedo californica AChE (TcAChE) and human butyrylcholinesterase (hBChE) enzymes to disclose binding interaction and orientation of these molecule into the active site gorge of respective receptors.
    Matched MeSH terms: Pyrimidines/chemical synthesis*; Pyrimidines/chemistry
  15. Gibson CM, Steg PG, Bahit MC, Al-Lamee R, Mehta SR, Mehran R, et al.
    N Engl J Med, 2026 Oct 22;395(16):1575-1584.
    PMID: 42670965 DOI: 10.1056/NEJMoa2608717
    BACKGROUND: Patients are at increased risk for recurrent ischemic events after an acute coronary syndrome event. Milvexian, an oral factor XIa inhibitor, may reduce the risk of major adverse clinical events with minimal bleeding risk.

    METHODS: In this phase 3, randomized, placebo-controlled trial, we evaluated the efficacy and safety of milvexian when added to standard antiplatelet therapy within 7 days after an acute coronary syndrome event. Patients were assigned in a 1:1 ratio to receive oral milvexian (25 mg twice daily) or matched placebo. The primary efficacy outcome was a composite of cardiovascular death, myocardial infarction, or ischemic stroke as evaluated in a time-to-event analysis. The principal safety outcome was Bleeding Academic Research Consortium (BARC) type 3c or 5 bleeding (intracranial or intraocular bleeding that compromises vision or fatal bleeding).

    RESULTS: After a planned interim analysis that was based on 556 adjudicated efficacy end points, the trial was terminated for futility. A total of 14,194 patients had been enrolled, with 7094 assigned to receive milvexian and 7100 to receive placebo. After a median follow-up of 12.2 months, a primary efficacy outcome event had occurred in 384 patients (5.4%) in the milvexian group and in 365 patients (5.1%) in the placebo group (hazard ratio, 1.05; 95% confidence interval, 0.91 to 1.21; P = 0.50). BARC type 3c or 5 bleeding occurred in 23 patients (0.3%) in the milvexian group and in 22 patients (0.3%) in the placebo group (P = 0.88).

    CONCLUSIONS: Among patients with a recent acute coronary syndrome event, milvexian did not decrease the risk of cardiovascular death, myocardial infarction, or ischemic stroke but did not increase the risk of intracranial or fatal bleeding, as compared with placebo. (Funded by Janssen Research and Development and Bristol Myers Squibb; LIBREXIA ACS ClinicalTrials.gov number, NCT05754957.).

    Matched MeSH terms: Pyrimidines/administration & dosage; Pyrimidines/adverse effects
  16. 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; Pyrimidines/adverse effects*
  17. 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; Pyrimidines/pharmacokinetics*
  18. Man CN, Noor NM, Lajis R
    J Chromatogr A, 2011 Sep 28;1218(39):7055-60.
    PMID: 21872876 DOI: 10.1016/j.chroma.2011.08.037
    Sildenafil analogues have been found adulterated in herbal preparations and food products that claim to have natural aphrodisiacs. In this study, a gas chromatography-mass spectrometry (GC-MS) assay was developed for the screening and identification of thioketone analogues of sildenafil. Thiopyrazolopyrimidine, a precursor or a cleavage product of thioketone analogue, exhibited characteristic fragment ions of m/z 328 and m/z 299 was found to be the best marker to screen the presence of general thioketone analogues. Identification by GC-MS assay was rapid and specific as all the studied thioketones showed characteristic mass fragmentations including their intact molecular ions. The developed GC-MS assay had successfully identified thiosildenafil, thiohomosildenafil and thiodimethylsildenafil in herbal preparation and food products.
    Matched MeSH terms: Pyrimidines/isolation & purification; Pyrimidines/chemistry*
  19. Yap E, Tumian NR, Azma RZ, Sharifah NA, Salwati S, Hamidah NH, et al.
    Malays J Pathol, 2017 Aug;39(2):107-113.
    PMID: 28866691 MyJurnal
    Clinical resistance to imatinib (IM) in chronic myeloid leukemia (CML) carries adverse consequences. We investigated 22 CML patients who developed IM-resistance for BCR-ABL kinase domain (KD) mutations. The median follow-up for this study was 101.9 months (range: 22.2 to 176.5 months) and the estimated mean overall survival was 150.87 months (95% CI: 130.0 to 171.0). Five out of 22 patients tested positive for BCR-ABL KD mutations: 2 had T315I, 2 had E255K and 1 had V289F mutations. Of the remaining 17 patients who did not harbor BCR-ABL KD mutations, 11 patients received nilotinib while the rest continued on IM. All 17 achieved haematological remission but only 5 patients achieved complete cytogenetic remission, 4 of whom did so after switching to nilotinib. Our study shows that most of our IM-resistant patients do not test positive for BCR-ABL KD mutations by available testing methods and the role of second generation tyrosine kinase inhibitors remains undetermined. A critical analysis of the BCR-ABL KD mutations and the underlying mechanisms/ pathways of BCR-ABL independent IM-resistance along with potential treatments in the horizon will be discussed.
    Matched MeSH terms: Pyrimidines
  20. Hall DA, Ray J, Watson J, Sharman A, Hutchison J, Harris P, et al.
    Hear Res, 2019 06;377:153-166.
    PMID: 30939361 DOI: 10.1016/j.heares.2019.03.018
    AUT00063 is an experimental new medicine that has been demonstrated to suppress spontaneous hyperactivity by modulating the action of voltage-gated potassium-channels in central auditory cortical neurons of a rodent model. This neurobiological property makes it a good candidate for treating the central component of subjective tinnitus but this has not yet been tested in humans. The main purpose of the QUIET-1 (QUest In Eliminating Tinnitus) trial was to examine the effect of AUT00063 on the severity of tinnitus symptoms in people with subjective tinnitus. The trial was a randomised, placebo-controlled, observer, physician and participant blinded multi-centre superiority trial with two parallel groups and a primary endpoint of functional impact on tinnitus 28 days after the first drug dosing day. The trial design overcame the scale and logistical challenges of delivering a scientifically robust, statistically powered multi-centre study for subjective tinnitus within the National Health Service in England. The trial was terminated early for futility. Overall, 212 participants consented across 18 sites with 91 participants randomised to groups using age, gender, tinnitus symptom severity and hearing status as minimisation factors. While the pharmacokinetic markers confirm the uptake of AUT00063 in the body, within the expected therapeutic range, with respect to clinical benefit findings indicated that AUT00063 was not effective in alleviating tinnitus symptoms (1.56 point change in Tinnitus Functional Index). In terms of clinical harms, results indicated that a daily dose of 800 mg capsules of AUT00063 taken for 28 days was safe and well tolerated. These findings provide significant advances in the drug development field for hearing sciences, but raise questions about the predictive validity of certain rodent models of noise-induced hearing loss and tinnitus, as least for the mechanism evaluated in the present study. Trial Registration: (EudraCT) 2014-002179-27; NCT02315508.
    Matched MeSH terms: Pyrimidines/adverse effects; Pyrimidines/pharmacokinetics; Pyrimidines/therapeutic use*
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