Displaying publications 1 - 20 of 80 in total

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  1. 2-Furoic piperazide derivatives as promising drug candidates of type 2 diabetes and Alzheimer's diseases: In vitro and in silico studies
    Abbasi MA, Hassan M, Ur-Rehman A, Siddiqui SZ, Hussain G, Shah SAA, et al.
    Comput Biol Chem, 2018 Dec;77:72-86.
    PMID: 30245349 DOI: 10.1016/j.compbiolchem.2018.09.007
    The heterocyclic compounds have been extensively reported for their bioactivity potential. The current research work reports the synthesis of some new multi-functional derivatives of 2-furoic piperazide (1; 1-(2-furoyl)piperazine). The synthesis was initiated by reacting the starting compound 1 with 3,5-dichloro-2-hydroxybenzenesulfonyl chloride (2) in a basic, polar and protic medium to obtain the parent sulfonamide 3 which was then treated with different electrophiles, 4a-g, in a polar and aprotic medium to acquire the designed molecules, 5a-g. These convergent derivatives were evaluated for their inhibitory potential against α-glucosidase, acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) enzymes. Acarbose was used as a reference standard for α-glucosidase inhibition while eserine for AChE and BChE inhibition. Some of the synthesized compounds were identified as promising inhibitors of these three enzymes and their bioactivity potentials were also supported by molecular docking study. The most active compounds among the synthetic analogues might be helpful in drug discovery and development for the treatment of type 2 diabetes and Alzhiemer's diseases.
    Matched MeSH terms: Piperazines/chemical synthesis; Piperazines/pharmacology*; Piperazines/chemistry
  2. A double-blind placebo-controlled trial of zopiclone 7.5 mg and temazepam 20 mg in insomnia
    Ngen CC, Hassan R
    Int Clin Psychopharmacol, 1990 Jul;5(3):165-71.
    PMID: 2230060
    Zopiclone, a cyclopyrrolone with hypnotic properties was compared with temazepam and placebo in the treatment of insomnia. After a week's washout period, suitable subjects were allocated at random to zopiclone 7.5 mg or temazepam 20 mg or placebo for 2 weeks. Measurements of psychomotor function using the Leed's psychomotor tester and letter cancellation were carried out on day 0, 7 and 14. Sleep latency, duration of sleep and number of times waking during the night were recorded on a sleep diary filled by the subjects nightly. Forty-four subjects completed the trial, 15 taking zopiclone, 16 taking temazepam and 10 taking placebo. Both zopiclone and temazepam had significant hypnotic properties when compared to placebo. Zopiclone increased total sleep time in both weeks of the trial while temazepam increased sleep time in the first week only. There was no significant deterioration in psychomotor performance at the end of both weeks for zopiclone. Critical flicker fusion was significantly increased in subjects on temazepam. There were no abnormalities for both zopiclone and temazepam subjects in the blood picture, renal profile, liver function, urine and ECG before and after the study. Zopiclone is an effective hypnotic comparable to temazepam.
    Matched MeSH terms: Piperazines/administration & dosage; Piperazines/adverse effects; Piperazines/therapeutic use*
  3. A man with concomitant polycythaemia vera and chronic myeloid leukemia: the dynamics of the two disorders
    Bee PC, Gan GG, Nadarajan VS, Latiff NA, Menaka N
    Int J Hematol, 2010 Jan;91(1):136-9.
    PMID: 20047097 DOI: 10.1007/s12185-009-0471-6
    The co-occurrence of JAK2 V617F mutation with BCR-ABL reciprocal translocation is uncommon. We report a 60-year-old man who initially presented with phenotype of polycythemia vera (PV), which evolved into chronic myeloid leukemia and back to PV once treatment with imatinib was commenced. JAK2 V617F mutation and BCR-ABL fusion transcripts were detected in the initial sample. However, JAK2 V617F alleles diminished when BCR-ABL mRNA burden increased and reappeared once the patient was commenced on imatinib. The dynamic interaction between JAK2 V617F and BCR-ABL implies that two independent clones exist with the JAK2 V617F clone only achieving clonal dominance when BCR-ABL positive clones are suppressed by imatinib.
    Matched MeSH terms: Piperazines/therapeutic use
  4. A randomized, placebo-controlled trial of aripiprazole for the treatment of methamphetamine dependence and associated psychosis
    Sulaiman AH, Gill JS, Said MA, Zainal NZ, Hussein HM, Guan NC
    Int J Psychiatry Clin Pract, 2013 Jun;17(2):131-8.
    PMID: 22486597 DOI: 10.3109/13651501.2012.667116
    The objectives of this study were to determine the efficacy and safety of aripiprazole for treatment of psychosis, retention and abstinence in patients with methamphetamine dependence.
    Matched MeSH terms: Piperazines/adverse effects; Piperazines/therapeutic use*
  5. Fulltext Acute oral toxicity evaluations of some zinc(II) complexes derived from 1-(2-salicylaldiminoethyl)piperazine Schiff bases in rats
    Salga MS, Ali HM, Abdulla MA, Abdelwahab SI
    Int J Mol Sci, 2012;13(2):1393-404.
    PMID: 22408397 DOI: 10.3390/ijms13021393
    The current study described the synthesis and the in vivo acute oral toxicity evaluations in Sprague Dawley rats. The compounds were characterized by elemental analyses, LC-MS, FTIR, (1)H NMR, (13)C NMR and UV-visible spectroscopy. In the acute toxicity study, a single administration of the compounds was performed orally to the rats at the single doses of 2000 mg/kg and they were then monitored for possible side effects, mortality or behavioral changes up to 14 days. The serum level of aspartate (AST), alanine aminotransferases (ALT), alkaline phosphate (ALP), triglyceride, high density lipoprotein (HDL), immunoglobulins (GAM) and the C-reactive proteins did not significantly change. The hematological indices white blood cells (WBC), haematocrit (HCT), red blood cells (RBC), mean corpuscular volume (MCV), mean corpuscular haemoglobin concentration (MCHC), and mean corpuscular hemoglobin (MCH) were within the normal range. The renal function indices examined were also within the reference range. Generally, the compounds exhibited low toxic effects as required for further in vivo therapeutic studies.
    Matched MeSH terms: Piperazines/toxicity*
  6. Alpha1A- and alpha1D-adrenoceptors are the major functional subtypes of renal alpha1-adrenoceptors in streptozotocin-induced diabetic and normal Sprague-Dawley rats
    Armenia, Sattar MA, Abdullah NA, Khan MA, Johns EJ
    Auton Autacoid Pharmacol, 2008 Jan;28(1):1-10.
    PMID: 18257746 DOI: 10.1111/j.1474-8673.2007.00412.x
    1 The present study investigated the effect of streptozotocin-induced diabetes on alpha(1)-adrenoceptor subtypes in rat renal resistance vessels. 2 Studies on renal haemodynamics were carried out 7 days after the last streptozotocin. Changes in renal blood flow were recorded in response to electrical stimulation of the renal nerve (RNS) and a range of adrenergic agonists; noradrenaline (NA), phenylephrine (PE) and methoxamine (MTX), either in the absence or the presence of nitrendipine (Nit), 5-methylurapidil (MEU), chlorethylclonidine (CEC) or BMY 7378. 3 In non-diabetic animals, Nit, MEU and BMY 7378 significantly attenuated renal vasoconstriction induced by adrenergic agonists, while CEC showed a significant accentuation in RNS-induced responses without having a significant effect on responses to adrenergic agonists. In diabetic rats, renal vasoconstriction was also significantly reduced in Nit-, MEU- and BMY 7378-treated groups and CEC potentiated RNS-induced contractions caused a change similar to that observed in non-diabetic rats. BMY 7378 significantly (P < 0.05) attenuated the PE- and MTX-induced vasoconstrictions but did not cause any significant (P > 0.05) alteration in the RNS- and NA-induced responses. 4 The results showed functional co-existence of alpha(1A)- and alpha(1D)-adrenoceptors in the renal vasculature of SD rats irrespective of the presence of diabetes. A possible minor contribution of prejunctional alpha-adrenoceptor subtype has also been suggested in either experimental group, particularly possible functional involvement of alpha(1B)-adrenoceptor subtypes in non-diabetic SD rats.
    Matched MeSH terms: Piperazines/pharmacology
  7. Fulltext An update on imatinib mesylate therapy in chronic myeloid leukaemia patients in a teaching hospital in Malaysia
    Bee PC, Gan GG, Tai YT, Haris AR, Chin E, Veera SN
    Singapore Med J, 2012 Jan;53(1):57-61.
    PMID: 22252185
    The introduction of imatinib mesylate in 1998 has changed the management of chronic myeloid leukaemia. It is now the first-line therapy for newly diagnosed chronic myeloid leukaemia patients worldwide. However, its long-term survival benefit still needs to be established in clinical setting among Asian patients.
    Matched MeSH terms: Piperazines/therapeutic use*
  8. Fulltext Analysis of the Binding of Aripiprazole to Human Serum Albumin: The Importance of a Chloro-Group in the Chemical Structure
    Sakurama K, Kawai A, Tuan Giam Chuang V, Kanamori Y, Osa M, Taguchi K, et al.
    ACS Omega, 2018 Oct 31;3(10):13790-13797.
    PMID: 30411049 DOI: 10.1021/acsomega.8b02057
    Aripiprazole (ARP), a quinolinone derivative, is an atypical antipsychotic drug that is used in the treatment of schizophrenia. ARP has an extensive distribution and more than 99% of the ARP and dehydro-ARP, the main active metabolite, is bound to plasma proteins. However, information regarding the protein binding of ARP is limited. In this study, we report on a systematic study of the protein binding of ARP. The interaction of ARP and structurally related compounds with human serum albumin (HSA) was examined using equilibrium dialysis, circular dichroism (CD) spectroscopy, fluorescent probe displacement, and an X-ray crystallographic analysis. The binding affinities (nK) for ARP and its main metabolite, dehydro-ARP with HSA were found to be significantly higher than other structurally related compounds. The results of equilibrium dialysis experiments and CD spectral data indicated that the chloro-group linked to the phenylpiperazine ring in the ARP molecule plays a major role in the binding of these ligands to HSA. Furthermore, fluorescent probe displacement results indicated that ARP appears to bind at the site II pocket in subdomain III. A detailed CD spectral analysis suggests that the chloro-group linked to the phenylpiperazine ring may control the geometry of the ARP molecule when binding in the site II binding pocket. X-ray crystallographic analysis of the ARP-HSA complex revealed that the distance between the chlorine atom at the 3-positon of dichlorophenyl-piperazine on ARP and the sulfur atom of Cys392 in HSA was 3.4-3.6 Å. A similar halogen bond interaction has also been observed in the HSA structure complexed with diazepam, which also contains a chloro-group. Thus, the mechanism responsible for the binding of ARP to a protein elucidated here should be relevant for assessing the pharmacokinetics and pharmacodynamics of ARP in various clinical situations and for designing new drugs.
    Matched MeSH terms: Piperazines
  9. Ascariasis: beliefs and practices of a rural Malay community
    Chen PC
    Med J Malaya, 1970 Mar;24(3):176-82.
    PMID: 4246796
    Matched MeSH terms: Piperazines/therapeutic use
  10. Asian sildenafil efficacy and safety study (ASSESS-1): a double-blind, placebo-controlled, flexible-dose study of oral sildenafil in Malaysian, Singaporean, and Filipino men with erectile dysfunction. The Assess-1 Study Group
    Tan HM, Moh CL, Mendoza JB, Gana T, Albano GJ, de la Cruz R, et al.
    Urology, 2000 Oct 1;56(4):635-40.
    PMID: 11018621 DOI: 10.1016/s0090-4295(00)00688-9
    OBJECTIVES:
    To evaluate the efficacy, safety, and tolerability of oral sildenafil in Asian men with erectile dysfunction of various causes (organic, psychogenic, or mixed) and of more than 6 months' duration.

    METHODS:
    In this double-blind, parallel-group trial conducted at eight centers in Malaysia, the Philippines, and Singapore, 254 men, 26 to 78 years old, were randomized to 12 weeks of sildenafil or placebo taken as needed 1 hour before anticipated sexual activity. Initially, the sildenafil (n = 127) or matching placebo (n = 127) dose was 50 mg but could be increased to 100 mg or decreased to 25 mg because of a lack of efficacy or intolerance, respectively. Efficacy was assessed by the 15-question International Index of Erectile Function, patients' event logs of sexual activity, and a global efficacy question about erections.

    RESULTS:
    The two primary efficacy variables relating to achievement and maintenance of an erection sufficient for sexual intercourse, as assessed by the mean scores for International Index of Erectile Function question 3 (4.22 versus 2.59) and question 4 (4.15 versus 2.41), were both significantly higher with sildenafil than with placebo (P <0.0001). In addition, the five separate International Index of Erectile Function domains of sexual function, the percentage of successful intercourse attempts, and the global efficacy assessment of erections revealed significantly greater treatment effects in favor of sildenafil (P <0.0001 versus placebo for all variables). Treatment-related adverse events occurred in 22.8% of patients who received sildenafil and in 10.2% of those who received placebo.

    CONCLUSIONS:
    Sildenafil is an effective and well-tolerated treatment for Asian men with erectile dysfunction of broad-spectrum etiology.
    Matched MeSH terms: Piperazines/adverse effects; Piperazines/therapeutic use*
  11. Association of ADRA2A and MTHFR gene polymorphisms with weight loss following antipsychotic switching to aripiprazole or ziprasidone
    Roffeei SN, Reynolds GP, Zainal NZ, Said MA, Hatim A, Aida SA, et al.
    Hum Psychopharmacol, 2014 Jan;29(1):38-45.
    PMID: 24424705 DOI: 10.1002/hup.2366
    Various genetic polymorphisms have been reported to be associated with antipsychotic-induced weight gain. In this study, we aimed to determine whether risk polymorphisms in 12 candidate genes are associated with reduction in body mass index (BMI) of patients following switching of antipsychotics to aripiprazole or ziprasidone.
    Matched MeSH terms: Piperazines/adverse effects; Piperazines/therapeutic use*
  12. 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: Piperazines/administration & dosage; Piperazines/adverse effects; Piperazines/pharmacokinetics; Piperazines/therapeutic use*
  13. BCR-ABL kinase domain mutations, including 2 novel mutations in imatinib resistant Malaysian chronic myeloid leukemia patients-Frequency and clinical outcome
    Elias MH, Baba AA, Azlan H, Rosline H, Sim GA, Padmini M, et al.
    Leuk. Res., 2014 Apr;38(4):454-9.
    PMID: 24456693 DOI: 10.1016/j.leukres.2013.12.025
    Discovery of imatinib mesylate (IM) as the targeted BCR-ABL protein tyrosine kinase inhibitor (TKI) has resulted in its use as the frontline therapy for chronic myeloid leukemia (CML) across the world. Although high response rates are observed in CML patients who receive IM treatment, a significant number of patients develop resistance to IM. Resistance to IM in patients has been associated with a heterogeneous array of mechanisms of which point mutations within the ABL tyrosine kinase domain (TKD) are the frequently documented. The types and frequencies of mutations reported in different population studies have shown wide variability. We screened 125 Malaysian CML patients on IM therapy who showed either TKI refractory or resistance to IM to investigate the frequency and pattern of BCR-ABL kinase domain mutations among Malaysian CML patients undergoing IM therapy and to determine the clinical significance. Mutational screening using denaturing high performance liquid chromatography (dHPLC) followed by DNA sequencing was performed on 125 IM resistant Malaysian CML patients. Mutations were detected in 28 patients (22.4%). Fifteen different types of mutations (T315I, E255K, G250E, M351T, F359C, G251E, Y253H, V289F, E355G, N368S, L387M, H369R, A397P, E355A, D276G), including 2 novel mutations were identified, with T315I as the predominant type of mutation. The data generated from clinical and molecular parameters studied were correlated with the survival of CML patients. Patients with Y253H, M351T and E355G TKD mutations showed poorer prognosis compared to those without mutation. Interestingly, when the prognostic impact of the observed mutations was compared inter-individually, E355G and Y253H mutations were associated with more adverse prognosis and shorter survival (P=0.025 and 0.005 respectively) than T315I mutation. Results suggest that apart from those mutations occurring in the three crucial regions (catalytic domain, P-loop and activation-loop), other rare mutations also may have high impact in the development of resistance and adverse prognosis. Presence of mutations in different regions of BCR-ABL TKD leads to different levels of resistance and early detection of emerging mutant clones may help in decision making for alternative treatment. Serial monitoring of BCR-ABL1 transcripts in CML patients allows appropriate selection of CML patients for BCR-ABL1 KD mutation analysis associated with acquired TKI resistance. Identification of these KD mutations is essential in order to direct alternative treatments in such CML patients.
    Matched MeSH terms: Piperazines/therapeutic use*
  14. Fulltext Clinical efficacy and safety of sildenafil citrate (Viagra) in a multi-racial population in Singapore: A retrospective study of 1520 patients
    Lim PH, Li MK, Ng FC, Chia SJ, Consigliere D, Gooren L, et al.
    Int J Urol, 2002 Jun;9(6):308-15.
    PMID: 12110094 DOI: 10.1046/j.1442-2042.2002.00425.x
    Sildenafil citrate (Viagra), a selective inhibitor of cGMP-specific phosphodiesterase type-5, has been used as an oral therapeutic drug for erectile dysfunction. The present paper is a clinical study of the success rate and side-effects of the use of sildenafil in a multi-racial population in Singapore.
    Matched MeSH terms: Piperazines/administration & dosage; Piperazines/adverse effects*; Piperazines/therapeutic use*
  15. Clinical impact of ABCC1 and ABCC2 genotypes and haplotypes in mediating imatinib resistance among chronic myeloid leukaemia patients
    Au A, Baba AA, Azlan H, Norsa'adah B, Ankathil R
    J Clin Pharm Ther, 2014 Dec;39(6):685-90.
    PMID: 25060527 DOI: 10.1111/jcpt.12197
    The introduction and success of imatinib mesylate (IM) has brought about a paradigm shift in chronic myeloid leukaemia (CML) treatment. However, despite the high efficacy of IM, clinical resistance develops due to a heterogeneous array of mechanisms. Pharmacogenetic variability as a result of genetic polymorphisms could be one of the most important factors influencing resistance to IM. The aim of this study was to investigate the association between genetic variations in drug efflux transporter ABCC1 (MRP1) and ABCC2 (MRP2) genes and response to IM in patients with CML.
    Matched MeSH terms: Piperazines/therapeutic use*
  16. Clinical safety profile of sildenafil in Singaporean men with erectile dysfunction: pre-marketing experience (ASSESS-I evaluation)
    Lim PH, Ng FC, Cheng CW, Wong MY, Chee CT, Moorthy P, et al.
    J Int Med Res, 2002 Mar-Apr;30(2):137-43.
    PMID: 12025521 DOI: 10.1177/147323000203000206
    Safety and tolerability of sildenafil citrate was assessed in a population subset of 60 Singaporean men with erectile dysfunction taken from the Asian Sildenafil Efficacy and Safety Study (ASSESS-I), a double-blind, placebo-controlled, flexible-dose study. The men, from two centres, with > or = 6 months' history of erectile dysfunction, were randomized to two treatment arms for 12 weeks. One group (30 patients) received sildenafil (initial dose 50 mg taken 1 h before sexual activity for the first 2 weeks, increased to 100 mg or decreased to 25 mg, according to efficacy and/or tolerability). The remaining 30 patients received a matching placebo. Incidence and type of adverse effects were evaluated at 2, 4, 8 and 12 weeks. Nine patients (30.0%) on sildenafil (33.1% in the full ASSESS-I study) and one patient (3.3%) on placebo (22.8% in the full ASSESS-I study) experienced treatment-related adverse events, the most frequent being headache in the sildenafil group (reported by five patients [16.7%]; 11.0% in the full ASSESS-I study). Flushing, visual disturbance, dizziness, insomnia, myalgia and back pain each occurred in one patient in the sildenafil group (3.3%); in the placebo group, one patient (3.3%) had headache. Importantly, the incidence of cardiovascular and respiratory system adverse events were relatively less than in the full ASSESS-I population (cardiovascular 3.3% in the present study versus 10.2% in the full ASSESS-I population; respiratory 3.3% versus 5.5%). All adverse events were transient and mild, and did not lead to treatment withdrawal. There was no effect on sitting blood pressure, heart rate or standard laboratory parameters; more importantly, there was no incidence of myocardial infarction, stroke or priapism. These results should reassure Singaporean patients and their physicians of the safety of sildenafil for erectile dysfunction.
    Matched MeSH terms: Piperazines/adverse effects*; Piperazines/therapeutic use
  17. Fulltext Cost-effectiveness analysis of olaparib maintenance therapy for BRCA mutation ovarian cancer in the public sector in Malaysia
    Yong CM, Yehgambaram PAP, Lee SWH
    PLoS One, 2024;19(2):e0298130.
    PMID: 38300930 DOI: 10.1371/journal.pone.0298130
    INTRODUCTION: Ovarian cancer is one of the most common cancer among women in Malaysia. Patients with ovarian cancer are often diagnosed at an advanced stage. Despite initial response to surgery and chemotherapy, most patients will experience a relapse. Olaparib has been reported have promising effects among BRCA mutated ovarian cancer patients. This study aimed to evaluate the cost-effectiveness of olaparib as a maintenance therapy for BRCA ovarian cancer in Malaysia.

    METHODS: We developed a four-state partitioned survival model which compared treatment with olaparib versus routine surveillance (RS) from a Malaysian healthcare perspective. Mature overall survival (OS) data from the SOLO-1 study were used and extrapolated using parametric models. Medication costs and healthcare resource usage costs were derived from local inputs and publications. Deterministic and probabilistic sensitivity analyses (PSA) were performed to explore uncertainties.

    RESULTS: In Malaysia, treating patients with olaparib was found to be more costly compared to RS, with an incremental cost of RM149,858 (USD 33,213). Patients treated with olaparib increased life years by 3.05 years and increased quality adjusted life years (QALY) by 2.76 (9.45 years vs 6.40 years; 7.62 vs 4.86 QALY). This translated to an incremental cost-effectiveness ratio (ICER) of RM 49,159 (USD10,895) per life year gained and RM54,357 (USD 12,047) per QALY gained, respectively. ICERs were most sensitive to time horizon of treatment, discount rate for outcomes, cost of treatment and health state costs, but was above the RM53,770/QALY threshold.

    CONCLUSION: The use of olaparib is currently not a cost-effective strategy compared to routine surveillance based upon the current price in Malaysia for people with ovarian cancer with BRCA mutation, despite the improvement in overall survival.

    Matched MeSH terms: Piperazines*
  18. Fulltext Cystathione gamma lyase/Hydrogen Sulphide Pathway Up Regulation Enhances the Responsiveness of α1A and α1B-Adrenoreceptors in the Kidney of Rats with Left Ventricular Hypertrophy
    Ahmad A, Sattar MA, Azam M, Abdulla MH, Khan SA, Hashmi F, et al.
    PLoS One, 2016;11(5):e0154995.
    PMID: 27191852 DOI: 10.1371/journal.pone.0154995
    The purpose of the present study was to investigate the interaction between H2S and NO (nitric oxide) in the kidney and to evaluate its impact on the functional contribution of α1A and α1B-adrenoreceptors subtypes mediating the renal vasoconstriction in the kidney of rats with left ventricular hypertrophy (LVH). In rats the LVH induction was by isoprenaline administration and caffeine in the drinking water together with intraperitoneal administration of H2S. The responsiveness of α1A and α1B to exogenous noradrenaline, phenylephrine and methoxaminein the absence and presence of 5-methylurapidil (5-MeU) and chloroethylclonidine (CEC) was studied. Cystathione gamma lyase (CSE), cystathione β synthase (CBS), 3-mercaptopyruvate sulphar transferase (3-MST) and endothelial nitric oxide synthase (eNOS) were quantified. There was significant up regulation of CSE and eNOS in the LVH-H2S compared to the LVH group (P<0.05). Baseline renal cortical blood perfusion (RCBP) was increased (P<0.05) in the LVH-H2S compared to the LVH group. The responsiveness of α1A-adrenergic receptors to adrenergic agonists was increased (P<0.05) after administration of low dose 5-Methylurapidil in the LVH-H2S group while α1B-adrenergic receptors responsiveness to adrenergic agonists were increased (P<0.05) by both low and high dose chloroethylclonidine in the LVH-H2S group. Treatment of LVH with H2S resulted in up-regulation of CSE/H2S, CBS, and 3-MST and eNOS/NO/cGMP pathways in the kidney. These up regulation of CSE/H2S, CBS, and 3-MST and eNOS/NO/cGMP pathways enhanced the responsiveness of α1A and α1B-adrenoreceptors subtypes to adrenergic agonists in LVH-H2S. These findings indicate an important role for H2S in modulating deranged signalling in the renal vasculature resulting from LVH development.
    Matched MeSH terms: Piperazines/pharmacology
  19. Designing of promising medicinal scaffolds for Alzheimer's disease through enzyme inhibition, lead optimization, molecular docking and dynamic simulation approaches
    Hassan M, Abbasi MA, Aziz-Ur-Rehman, Siddiqui SZ, Shahzadi S, Raza H, et al.
    Bioorg Chem, 2019 10;91:103138.
    PMID: 31446329 DOI: 10.1016/j.bioorg.2019.103138
    In the designed research work, a series of 2-furoyl piperazine based sulfonamide derivatives were synthesized as therapeutic agents to target the Alzheimer's disease. The structures of the newly synthesized compounds were characterized through spectral analysis and their inhibitory potential was evaluated against butyrylcholinesterase (BChE). The cytotoxicity of these sulfonamides was also ascertained through hemolysis of bovine red blood cells. Furthermore, compounds were inspected by Lipinki Rule and their binding profiles against BChE were discerned by molecular docking. The protein fluctuations in docking complexes were recognized by dynamic simulation. From our in vitro and in silico results 5c, 5j and 5k were identified as promising lead compounds for the treatment of targeted disease.
    Matched MeSH terms: Piperazines/chemical synthesis; Piperazines/metabolism; Piperazines/pharmacokinetics; Piperazines/chemistry*
  20. Differential effects of ketoconazole and primaquine on the pharmacokinetics and tissue distribution of imatinib in mice
    Soo GW, Law JH, Kan E, Tan SY, Lim WY, Chay G, et al.
    Anticancer Drugs, 2010 Aug;21(7):695-703.
    PMID: 20629201
    Imatinib, a selective inhibitor of c-KIT and Bcr-Abl tyrosine kinases, approved for the treatment of chronic myelogenous leukemia and gastrointestinal stromal tumors, shows further therapeutic potential for gliomas, glioblastoma, renal cell carcinoma, autoimmune nephritis and other neoplasms. It is metabolized by CYP3A4, is highly bound to alpha-1-acid glycoprotein and is a P-glycoprotein substrate limiting its brain distribution. We assess imatinib's protein binding interaction with primaquine, which also binds to alpha-1-acid glycoprotein, and its metabolic interaction with ketoconazole, which is a CYP3A4 inhibitor, on its pharmacokinetics and biodistribution. Male ICR mice, 9-12 weeks old were given imatinib PO (50 mg/kg) alone or co-administered with primaquine (12.5 mg/kg), ketoconazole (50 mg/kg) or both, and imatinib concentration in the plasma, kidney, liver and brain was measured at prescheduled time points by HPLC. Noncompartmental pharmacokinetic parameters were estimated. Primaquine increased 1.6-fold plasma AUC(0)--> infinity, C(Max) decreased 24%, T(Max) halved and t(1/2) and mean residence time were longer. Ketoconazole increased plasma AUC(0)-->infinity 64% and doubled the C(Max), but this dose did not affect t(1/2) or mean residence time. When ketoconazole and primaquine were co-administered, imatinib AUC(0)-->infinity and C(Max) increased 32 and 35%, respectively. Ketoconazole did not change imatinib's distribution efficiency in the liver and kidney, primaquine increased it two-fold and it was larger when both the drugs were co-administered with imatinib. Ketoconazole did not change brain penetration but primaquine increased it approximately three-fold. Ketoconazole and primaquine affect imatinib clearance, bioavailability and distribution pattern, which could improve the treatment of renal and brain tumors, but also increase toxicity. This would warrant hepatic and renal functions monitoring.
    Matched MeSH terms: Piperazines/pharmacokinetics*
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