Displaying publications 21 - 40 of 81 in total

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  1. 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*
  2. 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. Low WY, Ng CJ, Tan NC, Choo WY, Tan HM
    Asian J Androl, 2004 Jun;6(2):99-104.
    PMID: 15154082
    Aim: To explore the barriers faced by general practitioners (GPs) in the management of patients with erectile dysfunction (ED).
    Methods: This was a qualitative analysis of focus group discussions and in-depth interviews involving 28 Malaysian GPs.
    Results: GPs' perception of ED being not a serious condition was a major determinant of their prescribing practice. Doctor's age (younger), gender (female), short consultation time and lack of experience were cited as barriers. The GPs' prescribing habits were heavily influenced by the feedback from the first few patients under treatment, the uncertainty of etiology of ED without proper assessment and the profit margin with bulk purchase. Other barriers include Patients' coexisting medical conditions, older age, lower socio-economic status, unrealistic expectations and inappropriate use of the anti-impotent drugs. Cardiovascular side effects and cost were two most important drug barriers.
    Conclusion: The factors influencing the management of ED among the general practitioners were multiple and complex. An adequate understanding of how these factors (doctors, patients and drugs) interact can assist in the formulation and implementation of strategies that encourage GPs to identify and manage ED patients.
    Matched MeSH terms: Piperazines/adverse effects; Piperazines/economics; Piperazines/therapeutic use
  4. Iwata N, Ishigooka J, Kim WH, Yoon BH, Lin SK, Sulaiman AH, et al.
    Schizophr Res, 2020 01;215:408-415.
    PMID: 31471246 DOI: 10.1016/j.schres.2019.07.055
    BACKGROUND: Blonanserin is a second-generation antipsychotic used for the treatment of schizophrenia. This study determined the efficacy, safety and pharmacokinetics of a blonanserin transdermal patch in patients with acutely exacerbated schizophrenia.

    METHODS: This double-blind, multicenter, phase 3 study consisted of a 1-week observation period during which patients were treated with two patches of placebo, followed by a 6-week double-blind period where patients were randomized (1:1:1) to receive once-daily blonanserin 40 mg, blonanserin 80 mg, or placebo patches. The primary endpoint was the change from baseline in the total Positive and Negative Symptom Scale (PANSS) score. Safety assessments included treatment-emergent adverse events (TEAEs).

    RESULTS: Between December 2014 and October 2018, patients were recruited and randomly assigned to blonanserin 40 mg (n = 196), blonanserin 80 mg (n = 194), or placebo (n = 190); of these, 77.2% completed the study. Compared with placebo, blonanserin significantly improved PANSS total scores at 6 weeks (least square mean [LSM] difference vs placebo: -5.6 with blonanserin 40 mg; 95% confidence interval [CI] -9.6, -1.6; adjusted p = 0.007, and - 10.4 with blonanserin 80 mg; 95% CI -14.4, -6.4; adjusted p 

    Matched MeSH terms: Piperazines/administration & dosage; Piperazines/adverse effects; Piperazines/pharmacology*
  5. Hussain G, Abbasi MA, Rehman A, Siddiqui SZ, Shah SAA, Ahmad I, et al.
    Pak J Pharm Sci, 2018 May;31(3):857-866.
    PMID: 29716866
    In this work, a new series of 2-[4-(2-furoyl)-1-piperazinyl]-N-aryl/aralkyl acetamides has been synthesized and evaluated for their antibacterial potential. The synthesis was initiated by the reaction of different aryl/aralkyl amines (1a-u) with 2-bromoacetylbromide (2) to obtain N-aryl/aralkyl-2-bromoacetamides (3a-u). Equimolar quantities of different N-aryl/aralkyl-2-bromoacetamides (3a-u) and 2-furoyl-1-piperazine (4) was allowed to react in acetonitrile and in the presence of K2CO3, to form 2-[4-(2-furoyl)-1-piperazinyl]-N-aryl/aralkyl acetamides (5a-u). The structural elucidation was done by EI-MS, IR and 1H-NMR techniques of all the synthesized compounds. All of the synthesized molecules were active against various Gram positive and Gram negative bacterial strains. Among them 5o and 5c showed very excellent MIC values. The cytotoxicity of the molecules was also checked to find their utility as possible therapeutic agents, where 5c (0.51%) and 5g (1.32%) are found to be least toxic in the series.
    Matched MeSH terms: Piperazines
  6. Abbasi MA, Nazeer MM, Rehman A, Siddiqui SZ, Hussain G, Shah SA, et al.
    Pak J Pharm Sci, 2018 Nov;31(6):2477-2485.
    PMID: 30473521
    The aim of the present research work was synthesis of some 2-furyl[(4-aralkyl)-1-piperazinyl]methanone derivatives and to ascertain their antibacterial potential. The cytotoxicity of these molecules was also checked to find out their utility as possible therapeutic agents. The synthesis was initiated by reacting furyl(-1-piperazinyl)methanone (1) in N,N-dimethylformamide (DMF) and lithium hydride with different aralkyl halides (2a-j) to afford 2-furyl[(4-aralkyl)-1-piperazinyl]methanone derivatives (3a-j). The structural confirmation of all the synthesized compounds was done by IR, EI-MS, 1H-NMR and 13C-NMR spectral techniques and through elemental analysis. The results of in vitro antibacterial activity of all the synthesized compounds were screened against Gram-negative (S. typhi, E. coli, P. aeruginosa) and Gram-positive (B. subtilis, S. aureus) bacteria and were found to be decent inhibitors. Amongst the synthesized molecules, 3e showed lowest minimum inhibitory concentration MIC = 7.52±0.μg/mL against S. Typhi, credibly due to the presence of 2-bromobenzyl group, relative to the reference standard, ciprofloxacin, having MIC = 7.45±0.58μg/mL.
    Matched MeSH terms: Piperazines/chemical synthesis*; Piperazines/pharmacology*; Piperazines/toxicity
  7. Chan Kg, Yap Ac, Choo Ym
    Sains Malaysiana, 2016;45:1073-1077.
    Burkholderia cenocepacia and Serratia marcescens are Gram-negative proteobacteria commonly found in the natural
    environment and are also opportunistic pathogens that caused a number of human diseases. The fermentation culture of
    Burkholderia cenocepacia yielded three compounds, 4-(2-hydroxyethoxy)-phenol (1), Maculosin (2) and methyl myristate
    (3). Compound 2 was also isolated together with cyclo(L-Leu-L-Pro) (4) from Serratia marcescens. Compound 1 was
    isolated from a natural source for the first time and the first isolation of compounds 2-4 was also reported from both
    Burkholderia cenocepacia and Serratia marcescens.
    Matched MeSH terms: Piperazines
  8. Taha M, Irshad M, Imran S, Chigurupati S, Selvaraj M, Rahim F, et al.
    Eur J Med Chem, 2017 Dec 01;141:530-537.
    PMID: 29102178 DOI: 10.1016/j.ejmech.2017.10.028
    Piperazine Sulfonamide analogs (1-19) have been synthesized, characterized by different spectroscopic techniques and evaluated for α-amylase Inhibition. Analogs 1-19 exhibited a varying degree of α-amylase inhibitory activity with IC50 values ranging in between 1.571 ± 0.05 to 3.98 ± 0.397 μM when compared with the standard acarbose (IC50 = 1.353 ± 0.232 μM). Compound 1, 2, 3 and 7 showed significant inhibitory effects with IC50 value 2.348 ± 0.444, 2.064 ± 0.04, 1.571 ± 0.05 and 2.118 ± 0.204 μM, respectively better than the rest of the series. Structure activity relationships were established. Molecular docking studies were performed to understand the binding interaction of the compounds.
    Matched MeSH terms: Piperazines/chemical synthesis; Piperazines/pharmacology*; Piperazines/chemistry
  9. Tan KL, Ankathil R, Gan SH
    J Chromatogr B Analyt Technol Biomed Life Sci, 2011 Nov 15;879(30):3583-91.
    PMID: 22000961 DOI: 10.1016/j.jchromb.2011.09.048
    We developed a simple and sensitive method for the simultaneous detection of imatinib mesylate (IM) and its active metabolite, N-desmethyl imatinib (M1), in human serum samples. Separation was successfully achieved using an Agilent(®) ZORBAX Eclipse plus C(18) reversed phase column (50 mm × 2.1 mm, i.d.; 1.8 μm) under isocratic mobile phase conditions consisting of acetonitrile: 0.02 M potassium dihydrogen phosphate with 0.2% triethylamine at pH 3 (25:75, v/v) and ultra-violet detection was achieved at 235 nm. Extraction of the target compounds was completed using 100% cold acetonitrile. Good linearities (r(2)>0.99) for both IM and M1 were achieved for the concentration ranges of 50-1800 ng/mL and 50-360 ng/mL, respectively. The detection limits were 20 ng/mL and 10 ng/mL for M1 and IM, respectively. The intra- and inter-day precisions were less than 1% with percent recoveries of more than 90%. The method was successfully applied to calculate the pharmacokinetic parameters of chronic myeloid leukemia patients receiving imatinib. The method is suitable to be routinely applied for determination of IM and M1 in serum.
    Matched MeSH terms: Piperazines/blood*; Piperazines/metabolism; Piperazines/chemistry
  10. Mokhtar SU, Chin ST, Kee CL, Low MY, Drummer OH, Marriott PJ
    J Pharm Biomed Anal, 2016 Mar 20;121:188-196.
    PMID: 26808068 DOI: 10.1016/j.jpba.2016.01.034
    Application of gas chromatography-triple quadrupole mass spectrometry for identification, confirmation and quantification of 6 phosphodiesterase-5 (PDE-5) inhibitors (sildenafil, dimethylsildenafil, homosildenafil, thiosildenafil, thiodimethylsildenafil and thiohomosildenafil) in dietary supplements was investigated. The MS was operated in multiple reaction monitoring mode, for better sensitivity and selectivity. In this manner, the method is adequate to reduce background noise with less interference from co-eluting compounds in the samples. Two different ionisation techniques, electron ionisation (EI) and chemical ionisation (CI), were studied and compared. The chromatographic separation was performed on a short 10 m non-polar capillary column without any derivatisation step. This permitted fast analysis for all analogues with retention time less than 11 min, for both techniques. Use of backflushing can aid method retention time reduction and improves column maintenance. Evaluation of method validation included limit of detection (LOD), lower limit of quantitation (LLOQ), linearity, precision and recovery were performed for both EI and CI techniques. The LOD obtained varied from 0.03 to 1.50 μg/g and the LLOQ ranged from 0.10 to 5.00 μg/g. Good calibration linearity was obtained for all analogues for both techniques, with correlation coefficients (r(2)) higher than 0.99. Mean recoveries of all analogues using CI show higher values (83.4-108.8%) than that of EI (61.9-91.1%). The intra- and inter-assay precisions were evaluated for all analogues at spiked concentration of 10 μg/g and the relative standard deviation was less than 15% for both methods. These methods were then successfully applied to dietary supplement samples without prior derivatisation, confirming that the samples were adulterated with sildenafil and/or its analogues.
    Matched MeSH terms: Piperazines/chemistry
  11. Mak JW, Navaratnam V, Ramachandran CP
    Ann Trop Med Parasitol, 1991 Feb;85(1):131-7.
    PMID: 1888210
    An intense global collaborative effort under the leadership of the Steering Committee of the Filariasis Scientific Working Group of the Tropical Diseases Research Programme, World Health Organization, has brought together researchers, pharmaceutical chemists and clinicians in the development and search for antifilarial compounds which are more effective and more convenient to administer than diethylcarbamazine citrate, the current drug of choice for lymphatic filariasis. The Brugia spp.-rodent model has been used extensively for the primary screening and B. pahangi infections in the dog or cat for the secondary screening, of potential filaricides. Recently, the leaf-monkey (Presbytis spp.) infected with subperiodic B. malayi or Wuchereria kalimantani has been used for the tertiary evaluation and pharmacokinetic studies of compounds which have shown effectiveness in the primary and secondary screens. Both P. cristata and P. melalophos are extremely susceptible to subperiodic B. malayi infection, but the former is a better host as a higher peak microfilaremia and adult worm recovery rate were obtained. Although more than 30 potential filaricides have been evaluated in the tertiary screen, only a few compounds have shown some promise against lymphatic filariasis. CGP 20376, a 5-methoxyl-6-dithiocarbamic-S-(2-carboxy-ethyl) ester derivative of benzothiazole, had complete adulticidal and microfilaricidal activities against the parasite at a single oral dose of 20 mg kg-1. However, as the compound or its metabolites caused hepatotoxicity, its clinical use in the present formulation is not recommended.(ABSTRACT TRUNCATED AT 250 WORDS)
    Matched MeSH terms: Piperazines/therapeutic use
  12. Bera H, Abbasi YF, Yoke FF, Seng PM, Kakoti BB, Ahmmed SKM, et al.
    Int J Biol Macromol, 2019 May 15;129:552-563.
    PMID: 30707999 DOI: 10.1016/j.ijbiomac.2019.01.171
    Novel diethanolamine-grafted high-methoxyl pectin (DGP)-arabic gum (AG) modified montmorillonite (MMT) composites were developed for intragastric ziprasidone HCl (ZIP) delivery by combining floating and mucoadhesion mechanisms. The ZIP-loaded clay-biopolymer matrices were accomplished by ionotropic gelation protocol utilizing zinc acetate in the presence or absence of covalent crosslinker, glutaraldehyde (GA). Various formulations exhibited excellent drug entrapment efficiency (DEE, %) and sustained drug release profiles, which were influenced by the polymer-blend (DGP:AG) ratios, reinforcing filler (MMT) existence and crosslinking procedure. The optimal composites (F-3) demonstrated DEE of 61% and Q8h of 52% with outstanding buoyancy, mucin adsorption ability and biodegradability. The release profile of F-3 was best fitted in the Korsmeyer-Peppas model with Fickian diffusion driven mechanism. The mucin adsorption to composites F-3 followed Freundlich isotherms. The molar mass between crosslinks of composites (F-3) calculated employing Flory-Rehner equation was increased with temperature. Moreover, the thermal, X-ray and infrared analyses confirmed a compatible environment of drug in the composites, except certain extent of transformation of the crystalline drug to its amorphous form. The SEM studies revealed the spherical morphology of the composites. Thus, the newly developed DGP-AG-MMT composites are appropriate for gastroretentive ZIP delivery over an extended period of time.
    Matched MeSH terms: Piperazines/chemistry*
  13. Ahmad NF, Kamboh MA, Nodeh HR, Halim SNBA, Mohamad S
    Environ Sci Pollut Res Int, 2017 Sep;24(27):21846-21858.
    PMID: 28776296 DOI: 10.1007/s11356-017-9820-9
    The present work describes the successful functionalization/magnetization of bio-polymeric spores of Lycopodium clavatum (sporopollenin) with 1-(2-hydroxyethyl) piperazine. Analytical techniques, i.e., Fourier transform infrared (FT-IR), field emission scanning electron microscope (FESEM), energy-dispersive X-ray spectroscopy (EDS), and vibrating sample magnetometer (VSM), were used to confirm the formation of 1-(2-hydroxyethyl) piperazine-functionalized magnetic sporopollenin (MNPs-Sp-HEP). The proposed adsorbent (MNPs-Sp-HEP) was used for the removal of noxious Pb(II) and As(III) metal ions from aqueous media through a batch-wise method. Different experimental parameters were optimized for the effective removal of selected noxious metal ions. Maximum adsorption capacity (q m ) 13.36 and 69.85 mg g-1 for Pb(II) and As(III), respectively, were obtained. Thermodynamic parameters such as free energy (ΔG°), entropy (ΔS°), and enthalpy (ΔH°) were also studied from the adsorption results and were used to elaborate the mechanism of their confiscation. The obtained results indicated that newly adsorbent can be successfully applied for the decontamination of noxious Pb(II) and As(III) from the aqueous environment.
    Matched MeSH terms: Piperazines/chemistry
  14. Zeb A, Abbasi MA, Aziz-Ur-Rehman, Siddiqui SZ, Hassan M, Javed Q, et al.
    Chem Biodivers, 2024 Apr;21(4):e202400133.
    PMID: 38363553 DOI: 10.1002/cbdv.202400133
    In the aimed research study, a new series of N-(aryl)-3-[(4-phenyl-1-piperazinyl)methyl]benzamides was synthesized, which was envisaged as tyrosinase inhibitor. The structures of these newly designed molecules were verified by IR, 1H-NMR, 13C-NMR, EI-MS and CHN analysis data. These molecules were screened against tyrosinase and their inhibitory activity explored that these 3-substituted-benzamides exhibit good to excellent potential, comparative to the standard. The Kinetics mechanism was investigated through Lineweaver-Burk plots which depicted that molecules inhibited this enzyme in a competitive mode. Moreover, molecular docking was also performed to determine the binding interaction of all synthesized molecules (ligands) with the active site of tyrosinase enzyme and the results showed that most of the ligands exhibited efficient binding energy values. Therefore, it is anticipated that these molecules might serve as auspicious therapeutic scaffolds for treatment of the tyrosinase associated skin disorders.
    Matched MeSH terms: Piperazines*
  15. 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*
  16. Tan SY, Kan E, Lim WY, Chay G, Law JH, Soo GW, et al.
    J Pharm Pharmacol, 2011 Jul;63(7):918-25.
    PMID: 21635257 DOI: 10.1111/j.2042-7158.2011.01296.x
    The pharmacokinetic interaction between metronidazole, an antibiotic-antiparasitic drug used to treat anaerobic bacterial and protozoal infections, and imatinib, a CYP3A4, P-glycoprotein substrate kinase inhibitor anticancer drug, was evaluated.
    Matched MeSH terms: Piperazines/adverse effects; Piperazines/blood; Piperazines/metabolism; Piperazines/pharmacokinetics*
  17. 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*
  18. 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*
  19. Bee PC, Gan GG, Teh A, Haris AR
    Med J Malaysia, 2006 Dec;61(5):547-52.
    PMID: 17623954 MyJurnal
    This study was done to assess the overall response rate of imatinib mesylate in local patients with chronic myeloid leukaemia. A total of 69 patients were recruited with male/female ratio of 7:3. Of the 69 patients; 35% were in the chronic phase, 41% were in the accelerated phase, 17% were in blast crisis and the remaining 7% were after stem cell transplantation. Complete haematological response rates of patients in chronic phase, accelerated phase and blast crisis were 95.8%, 96.4% and 41.7% respectively. Thirty-eight percent of patients achieved complete cytogenetic response and 10% achieved partial cytogenetic response. The cytogenetic response rates were 80%, 41.7% and 18.2% in chronic, accelerated and blast crisis phase respectively (p < 0.005). Twenty-six percent of patients developed anaemia, 13% had neutropenia and 12% had thrombocytopenia after starting on treatment. In addition, 14% of patients developed peripheral oedema, 13% complained of musculoskeletal pain, 12% had gastrointestinal side effects which include nausea, vomiting and diarrhoea, 9% had grade 1 hepatotoxicity, 7% developed skin rashes and one patient had an abnormal renal function test. Patients taking 600mg or higher dosage of imatinib had more gastrointestinal side effects. Patients who weighed less than 60kg had a much higher risk of developing anaemia. Anaemia was a negative predictor of cytogenetic response. Presenting high white blood cell counts and absence of cytogenetic response were also negative predictors of survival. Overall survival was 87%. This was affected by the different phases of disease (chronic phase was better than accelerated and blast crisis) (p < 0.001). In conclusion, our local CML patients did well on treatment with imatinib.
    Matched MeSH terms: Piperazines/adverse effects; Piperazines/therapeutic use*
  20. Chng WJ, Tan LH
    Leuk. Res., 2005 Jun;29(6):719-20.
    PMID: 15863215
    Matched MeSH terms: Piperazines/adverse effects*; Piperazines/therapeutic use*
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