Displaying publications 1 - 20 of 440 in total

Abstract:
Sort:
  1. Zou D, Goh KL
    J Gastroenterol Hepatol, 2017 Jun;32(6):1152-1159.
    PMID: 28024166 DOI: 10.1111/jgh.13712
    Both proton pump inhibitors (PPIs) and clopidogrel are widely prescribed in the Asia-Pacific population. PPIs are the mainstay therapeutic agents for prophylaxis against aspirin gastropathy and for acid-related disorders including gastroesophageal reflux disease. They are also co-prescribed with oral anticoagulant agents and with dual-antiplatelet therapy for the treatment and prevention of gastrointestinal bleeding. Clopidogrel belongs to the drug class of thienopyridines and is currently the most widely prescribed oral anticoagulant agent either alone or in combination with aspirin. Platelet inhibition by clopidogrel is prone to significant inter-individual variability and is believed to be affected by several factors such as genetics and drug-drug interactions. Since it was first reported in 2009, the potential for drug-drug interactions between PPIs and clopidogrel has remained headline news, and its significance in clinical practice is the subject of an ongoing debate. For East Asian patients in particular, the clinical relevance of the interaction between PPIs and clopidogrel remains unclear because of conflicting data, as well as underrepresentation of East Asian subjects in landmark trials. Increased CYP2C19 genetic polymorphisms in individuals from Asia-Pacific countries only fuel the confusion. Recent studies in East Asian cohorts suggests that the potential of PPIs to attenuate the efficacy of clopidogrel could be minimized by the use of newer PPIs with weaker affinity for the CYP2C19 isoenzyme, namely, pantoprazole, dexlansoprazole, and rabeprazole. This review aims to help clinicians choose the most appropriate PPI for co-prescription with clopidogrel in patients from Asia-Pacific countries.
    Matched MeSH terms: Polymorphism, Genetic
  2. Zimisuhara B, Valdiani A, Shaharuddin NA, Qamaruzzaman F, Maziah M
    Int J Mol Sci, 2015 Jun 24;16(7):14369-94.
    PMID: 26114389 DOI: 10.3390/ijms160714369
    Genetic structure and biodiversity of the medicinal plant Ficus deltoidea have rarely been scrutinized. To fill these lacunae, five varieties, consisting of 30 F. deltoidea accessions were collected across the country and studied on the basis of molecular and morphological data. Molecular analysis of the accessions was performed using nine Inter Simple Sequence Repeat (ISSR) markers, seven of which were detected as polymorphic markers. ISSR-based clustering generated four clusters supporting the geographical distribution of the accessions to some extent. The Jaccard's similarity coefficient implied the existence of low diversity (0.50-0.75) in the studied population. STRUCTURE analysis showed a low differentiation among the sampling sites, while a moderate varietal differentiation was unveiled with two main populations of F. deltoidea. Our observations confirmed the occurrence of gene flow among the accessions; however, the highest degree of this genetic interference was related to the three accessions of FDDJ10, FDTT16 and FDKT25. These three accessions may be the genetic intervarietal fusion points of the plant's population. Principal Components Analysis (PCA) relying on quantitative morphological characteristics resulted in two principal components with Eigenvalue >1 which made up 89.96% of the total variation. The cluster analysis performed by the eight quantitative characteristics led to grouping the accessions into four clusters with a Euclidean distance ranged between 0.06 and 1.10. Similarly, a four-cluster dendrogram was generated using qualitative traits. The qualitative characteristics were found to be more discriminating in the cluster and PCA analyses, while ISSRs were more informative on the evolution and genetic structure of the population.
    Matched MeSH terms: Polymorphism, Genetic*
  3. Zilfalil BA, Hoh BP, Nizam MZ, Liza-Sharmini AT, Teh LK, Ismail R
    J Clin Pharm Ther, 2006 Dec;31(6):637-40.
    PMID: 17176369
    Seventeen single nucleotide polymorphisms (SNPs) have been identified so far, within the beta-2 receptor (beta(2) AR) gene. The presence of so many SNPs within the beta(2) AR gene causes a problem, for those studying beta(2) AR pharmacogenetics, in relation to which SNPs to choose. Most of the work has focused on the three common SNPs within the coding block (alleles 16, 27 and 164) and the techniques developed have been for these three functionally important alleles.
    Matched MeSH terms: Polymorphism, Genetic*
  4. Zhou Q, Cheung YB, Jada SR, Lim WT, Kuo WL, Gray JW, et al.
    Cancer Biol Ther, 2006 Nov;5(11):1445-9.
    PMID: 17102595
    AIM: The purpose of this study was to test the hypothesis if longer CA dinucleotide repeats are more common in the Asian population and also to gain insights into the interplay between the CA dinucleotide repeats and the frequencies of EGFR gene expression and amplifications as this might have therapeutic implications with regards to treatment with tyrosine kinase inhibitors.

    MATERIALS AND METHODS: The EGFR intron 1 polymorphism was analysed in three distinct healthy Asian subjects, namely, Chinese (N = 96), Malays (N = 98) and Indians (N = 100). Comparative genomic hybridisation was performed to investigate for changes in DNA copy number in relation to the polymorphic CA dinucleotide repeats in breast tumor tissues (N = 22).

    RESULTS: The frequency of short alleles with 14 and 15 CA repeats were most common in the Asian populations and significantly higher than those reported for Caucasians. The frequency of 20 CA repeats was 5%, almost 13-fold lower than previous reports. EGFR amplifications were detected in 23% and 11% of breast tumor tissues harboring short and long CA repeats, respectively.

    CONCLUSION: Our results show that the frequency of alleles encoding for short CA dinucleotide repeats is common in Asian populations. EGFR expression and amplification levels were also higher in Asian breast tumor tissues with short CA dinucleotide repeats. These findings suggest that the EGFR intron 1 polymorphism may influence response to treatment with tyrosine kinase inhibitors in breast cancer patients and further studies are warranted.

    Matched MeSH terms: Polymorphism, Genetic
  5. Zhao B, Lee EJ, Yeoh PN, Gong NH
    Pharmacogenetics, 1998 Aug;8(4):299-304.
    PMID: 9731716
    The xenobiotic metabolizing enzymes N-acetyltransferases (NATs) are important for the biotransformation and/or bioactivation of drugs and carcinogens. NATs are coded for in humans by two distinct genes, designated NAT1 and NAT2. NAT1, which was originally thought to be monomorphic, was recently reported to exhibit variation in human populations. Recent studies suggested that a genetic polymorphism of NAT1 may be associated with colorectal cancer risk. The distributions of NAT1 allele and genotype frequencies in unrelated individuals among Indian (n = 140), Malay (n = 122) and Chinese (n = 181) populations in Singapore were characterized by polymerase chain reaction-restriction fragment length polymorphism and allele-specific-polymerase chain reaction. The allelic frequencies of NAT1*3, NAT1*4, NAT1*10 and NAT1*11 among Indians were 0.3, 0.51, 0.17 and 0.02, respectively. The corresponding NAT1 allelic frequencies in Malays were 0.29, 0.30, 0.39 and 0.02, respectively, and were similar to those in Chinese in the region. The allelic frequencies of NAT1*3, NAT1*4, NAT1*10 and NAT1*11 among Chinese were 0.33, 0.35, 0.30 and 0.02, respectively. These findings are of importance for the determination of cancer risk in these populations. In addition, nucleotide changes at positions 350-351 (GG to CC) and 497-499 (GGG to CCC) of the NAT1 gene were not found in the alleles of the populations studied.
    Matched MeSH terms: Polymorphism, Genetic*
  6. Zarinah KH, Abdullah F, Tan SG
    Ann Hum Biol, 1984 11 1;11(6):533-6.
    PMID: 6084457
    Three genetic markers, red-cell UMPK, PGP and serum AMY2 were investigated in Malaysians of Malay, Chinese and Indian ancestries using starch-gel and agarose-gel electrophoresis. UMPK was found to be polymorphic in all three races. Variants were observed for PGP in Malays; in Indians it is a polymorphic marker whereas it is monomorphic in Chinese. AMY2 was polymorphic only in Indians. The UMPK1 frequencies in Malays, Chinese and Indians, respectively, are 0.851, 0.880 and 0.942. The PGP1 frequencies are 0.991, 1.000, 0.962, and the AMY1(2) frequencies are 1.000, 1.000 and 0.983.
    Matched MeSH terms: Polymorphism, Genetic
  7. Zangeneh FZ, Shoushtari MS, Shojaee S, Aboutorabi E
    Int J Reprod Biomed, 2020 Mar;18(3):165-174.
    PMID: 32309765 DOI: 10.18502/ijrm.v18i3.6712
    Background: Polycystic ovary syndrome (PCOS) is a multifactorial and heterogeneous disease that has a potent inheritable component based on familial clustering. Despite many studies in the genetic field of PCOS, the genes that are involved in the causes of this syndrome have not been thoroughly investigated.

    Objective: The purpose of this study was to establish the occurrence of the Trp64Arg polymorphism of beta3 adrenergic receptor in non-obese women with PCOS.

    Materials and Methods: This cross-sectional study was performed on 100 women with PCOS and normal women as the control group in Imam Khomeini Hospital of Tehran in 2016-2017. Peripheral blood sample (2 cc) was obtained from two groups for genomic DNA based on the gene bank. Polymorphisms were genotyped by of using ADRB3 Trp64Arg. Then the DNA was extracted by genomic kiagen kit. The primer was analyzed for PCR based on gene bank by using Primer3 software and then confirmed by primer Blast tool at NCBI site to conformity to the beta-3 adrenergic receptor gene. The protein changes were assessment by the Clastal W software.

    Results: The sequence analysis presented in NCBI, transcript variant 1, with the code NM_000025.2, shows changes in the amino acid sequence of exon 1 in women with PCOS. Polymorphism in the codon 64 encoding the amino acid tryptophan (W) occurred in the nucleotide c.T190C, which changed the nucleotide T to C and then the amino acid sequence of the tryptophan was altered to arginine pW64R.

    Conclusion: T-C polymorphism is evident in the codon 64 of the adrenergic β3 receptor in patients with PCOS. Therefore, Beta3 adrenergic receptor gene polymorphism (Thr164Ile) associates with this syndrome in nonobese women.

    Matched MeSH terms: Polymorphism, Genetic
  8. Zaki NM, Singh R, Rosli R, Ismail I
    Int J Mol Sci, 2012;13(4):4069-88.
    PMID: 22605966 DOI: 10.3390/ijms13044069
    Species-specific simple sequence repeat (SSR) markers are favored for genetic studies and marker-assisted selection (MAS) breeding for oil palm genetic improvement. This report characterizes 20 SSR markers from an Elaeis oleifera genomic library (gSSR). Characterization of the repeat type in 2000 sequences revealed a high percentage of di-nucleotides (63.6%), followed by tri-nucleotides (24.2%). Primer pairs were successfully designed for 394 of the E. oleifera gSSRs. Subsequent analysis showed the ability of the 20 selected E. oleifera gSSR markers to reveal genetic diversity in the genus Elaeis. The average Polymorphism Information Content (PIC) value for the SSRs was 0.402, with the tri-repeats showing the highest average PIC (0.626). Low values of observed heterozygosity (H(o)) (0.164) and highly positive fixation indices (F(is)) in the E. oleifera germplasm collection, compared to the E. guineensis, indicated an excess of homozygosity in E. oleifera. The transferability of the markers to closely related palms, Elaeis guineensis, Cocos nucifera and ornamental palms is also reported. Sequencing the amplicons of three selected E. oleifera gSSRs across both species and palm taxa revealed variations in the repeat-units. The study showed the potential of E. oleifera gSSR markers to reveal genetic diversity in the genus Elaeis. The markers are also a valuable genetic resource for studying E. oleifera and other genus in the Arecaceae family.
    Matched MeSH terms: Polymorphism, Genetic
  9. Zakaria Z, Badhan RKS
    Eur J Pharm Sci, 2018 Jul 01;119:90-101.
    PMID: 29635009 DOI: 10.1016/j.ejps.2018.04.012
    Lumefantrine is a widely used antimalarial in children in sub-Saharan Africa and is predominantly metabolised by CYP3A4. The concomitant use of lumefantrine with the antiretroviral efavirenz, which is metabolised by CYP2B6 and is an inducer of CYP3A4, increases the risk of lumefantrine failure and can result in an increased recrudescence rate in HIV-infected children. This is further confounded by CYP2B6 being highly polymorphic resulting in a 2-3 fold higher efavirenz plasma concentration in polymorphic subjects, which enhances the potential for an efavirenz-lumefantrine drug-drug interaction (DDI). This study developed a population-based PBPK model capable of predicting the impact of efavirenz-mediated DDIs on lumefantrine pharmacokinetics in African paediatric population groups, which also considered the polymorphic nature of CYP2B6. The validated model demonstrated a significant difference in lumefantrine target day 7 concentrations (Cd7) in the presence and absence of efavirenz and confirmed the capability of efavirenz to initiate this DDI. This was more apparent in the *6/*6 compared to *1/*1 population group and resulted in a significantly lower (P 
    Matched MeSH terms: Polymorphism, Genetic
  10. Zainuddin Z, Teh LK, Suhaimi AW, Ismail R
    J Clin Pharm Ther, 2006 Apr;31(2):187-91.
    PMID: 16635054
    CYP2C9 is one of the major drug metabolizing enzymes for many drugs including warfarin, NSAIDs and losartan. It is polymorphic in many populations. Data on the distribution of CYP2C9 and the implication of CYP2C9 polymorphism in the Malaysian population is lacking. Our objectives were therefore to investigate the prevalence of CYP2C9 variants among unrelated healthy volunteers of Malays, Chinese and Indians in Malaysia.
    Matched MeSH terms: Polymorphism, Genetic
  11. Zainuddin Z, Teh LK, Suhaimi AW, Salleh MZ, Ismail R
    Clin Chim Acta, 2003 Oct;336(1-2):97-102.
    PMID: 14500040 DOI: 10.1016/s0009-8981(03)00319-x
    BACKGROUND: Cytochrome P4502C9 (CYP2C9), a principle drug-metabolizing enzyme is polymorphic in humans and is responsible for important pharmacokinetic and pharmacodynamic variations of CYP2C9 substrates. We developed an allele-specific multiplex polymerase chain reaction (PCR) method for the detection of common CYP2C9 alleles.
    METHOD: Genomic DNA was extracted from blood obtained from 40 unrelated healthy Malaysian Indian volunteers. The DNA was subjected to a first PCR that was used to amplify both exons 3 and 7 simultaneously in one reaction tube and a second PCR that was used to detect the polymorphic sites of CYP2C9 alleles using allele-specific primers. Sequencing was performed to validate the test results.
    RESULTS: We were successful in amplifying the fragments of interest from the DNA samples. The method was also reproducible and specific. The amplified sequences showed 100% homology to CYP2C9 sequence.
    CONCLUSION: This is the first nested allele-specific multiplex PCR method reported to allow for the simultaneously detection of five CYP2C9 alleles.
    Matched MeSH terms: Polymorphism, Genetic/genetics
  12. Zainal SA, Md Daud MK, Abd Rahman N, Zainuddin Z, Alwi Z
    Int J Pediatr Otorhinolaryngol, 2012 Aug;76(8):1175-9.
    PMID: 22613756 DOI: 10.1016/j.ijporl.2012.04.027
    To identify the mutations in the GJB2 gene and to determine its association with non-syndromic hearing loss in Malays.
    Matched MeSH terms: Polymorphism, Genetic
  13. Zainal Abidin S, Tan EL, Chan SC, Jaafar A, Lee AX, Abd Hamid MH, et al.
    BMC Neurol, 2015;15:59.
    PMID: 25896831 DOI: 10.1186/s12883-015-0316-2
    Impulse control disorder (ICD) and behaviours (ICB) represent a group of behavioural disorders that have become increasingly recognised in Parkinson's disease (PD) patients who previously used dopaminergic medications, particularly dopamine agonists and levodopa. It has been suggested that these medications can lead to the development of ICB through the abnormal modulation of dopaminergic transmission and signalling in the mesocorticolimbic dopaminergic system. Several studies have reported an association between polymorphisms in the dopamine receptor (DRD) and N-methyl-D-aspartate 2B (GRIN2B) genes with the development of ICB in PD (PD-ICB) patients. Thus, this study aimed to investigate the association of selected polymorphisms within the DRD and GRIN2B genes with the development of ICB among PD patients using high resolution melt (HRM) analysis.
    Matched MeSH terms: Polymorphism, Genetic
  14. Zain SM, Mohamed Z, Mahadeva S, Cheah PL, Rampal S, Chin KF, et al.
    J Gastroenterol Hepatol, 2013 May;28(5):873-9.
    PMID: 23278404 DOI: 10.1111/jgh.12104
    Genetic polymorphism has been implicated as a factor for the occurrence of non-alcoholic fatty liver disease (NAFLD). This study attempted to assess whether polymorphisms in the leptin receptor (LEPR) gene and its combined effect with patatin-like phospholipase domain-containing protein 3 (PNPLA3/adiponutrin) are associated with risk of NAFLD.
    Matched MeSH terms: Polymorphism, Genetic
  15. Zahidin MA, Omar WBW, Taib WRW, Japning JRR, Abdullah MT
    Data Brief, 2018 Dec;21:2609-2615.
    PMID: 30761343 DOI: 10.1016/j.dib.2018.10.158
    Orang Asli is the aboriginal people in Peninsular Malaysia who have been recognized as indigenous to the country and still practicing traditional lifestyle. The molecular interest on the Orang Asli started when the earliest prehistoric migration occurred approximately 200 kya and entering Peninsular Malaysia 50 kya in stages. A total of three groups of Orang Asli present in Peninsular Malaysia, namely, Negrito also known as Semang, Senoi and Proto Malays. Through records, there is no research has been conducted on mtDNA variations in the Semoq Beri population, one of the tribes in Senoi group. In this report, variations of mtDNA were analysed in the population in Hulu Terengganu as an initial effort to establish the genetic characterisation and elucidating the history of Orang Asli expansion in Peninsular Malaysia. An array of mtDNA parameters was estimated and the observed polymorphisms with their respective haplogroups in comparison to rCRS were inferred respectively. The DNA sequences are registered in the NCBI with accession numbers KY853670-KY853753.
    Matched MeSH terms: Polymorphism, Genetic
  16. Zahary MN, Kaur G, Abu Hassan MR, Singh H, Naik VR, Ankathil R
    World J Gastroenterol, 2012 Feb 28;18(8):814-20.
    PMID: 22371642 DOI: 10.3748/wjg.v18.i8.814
    To investigate the protein expression profile of mismatch repair (MMR) genes in suspected cases of Lynch syndrome and to characterize the associated germline mutations.
    Matched MeSH terms: Polymorphism, Genetic
  17. Zahari Z, Ismail R
    Drug Metab. Pharmacokinet., 2014;29(1):29-43.
    PMID: 23759977
    CYP2D6 polymorphisms show large geographical and interethnic differences. Variations in CYP2D6 activity may impact upon a patient's pain level and may contribute to interindividual variations in the response to opioids. This paper reviews the evidence on how CYP2D6 polymorphisms might influence pain sensitivity and clinical response to codeine and tramadol. For example, it is shown that (1) CYP2D6 poor metabolizers (PMs) may be less efficient at synthesizing endogenous morphine compared with other metabolizers. In contrast, ultra-rapid metabolizers (UMs) may be more efficient than other metabolizers at synthesizing endogenous morphine, thus strengthening endogenous pain modulation. Additionally, for codeine and tramadol that are bioactivated by CYP2D6, PMs may undergo no metabolite formation, leading to inadequate analgesia. Conversely, UMs may experience quicker analgesic effects but be prone to higher mu-opioid-related toxicity. The literature suggested the potential usefulness of the determination of CYP2D6 polymorphisms in elucidating serious adverse events and in preventing subsequent inappropriate selection or doses of codeine and tramadol. Notably, even though many studies investigated a possible role of the CYP2D6 polymorphisms on pain sensitivity, pharmacokinetics and pharmacodynamics of these drugs, the results of analgesia and adverse effects are conflicting. More studies are required to demonstrate genetically determined unresponsiveness and risk of developing serious adverse events for patients with pain and these should involve larger numbers of patients in different population types.
    Matched MeSH terms: Polymorphism, Genetic
  18. Zahari Z, Teh LK, Ismail R, Razali SM
    Psychiatr Genet, 2011 Aug;21(4):183-9.
    PMID: 21206399 DOI: 10.1097/YPG.0b013e3283437250
    Variations in the gene for dopamine D2 receptor (DRD2) might have an influence on the outcome of antipsychotic treatment in schizophrenia. The objective of this study was to investigate the influence of DRD2 polymorphisms on treatment outcomes in patients with schizophrenia.
    Matched MeSH terms: Polymorphism, Genetic*
  19. Zahari Z, Lee CS, Ibrahim MA, Musa N, Mohd Yasin MA, Lee YY, et al.
    Drug Alcohol Depend, 2016 08 01;165:143-50.
    PMID: 27289271 DOI: 10.1016/j.drugalcdep.2016.05.028
    BACKGROUND: CYP2B6 polymorphisms contribute to inter-individual variations in pharmacokinetics of methadone. Increased pain sensitivity is frequently reported by opioid dependent patients on methadone maintenance therapy (MMT). It is possible, therefore, that genetic polymorphisms in CYP2B6, which affects the metabolism of methadone, influence pain sensitivity among patients on MMT. This study investigated CYP2B6 polymorphisms and pain sensitivity in this group.

    METHODS: The cold pressor pain responses of 148 opioid dependent patients receiving MMT were evaluated using the cold pressor test (CPT). DNA was extracted from whole blood and subjected to polymerase chain reaction (PCR)-genotyping.

    RESULTS: Of the 148 subjects, 77 (52.0%) were carriers of CYP2B6*6 allele. CYP2B6*6 allele carriers had shorter cold pain threshold and pain tolerance times than non-carriers of CYP2B6*6 allele (21.05s vs 33.69s, p=0.036 and 27.15s vs 44.51s, p=0.020, respectively). Pain intensity scores of the CYP2B6*6 allele carriers was 67.55, whereas that of the CYP2B6*6 allele non-carriers was 64.86 (p=0.352).

    CONCLUSION: Our study indicates that the CYP2B6*6 allele is associated with a lower pain threshold and lower pain tolerance among males with opioid dependence on MMT. The CYP2B6*6 allele may provide a mechanistic explanation for clinical observations of heightened pain sensitivity among opioid dependent patients receiving MMT.

    Matched MeSH terms: Polymorphism, Genetic
  20. Zahari Z, Lee CS, Ibrahim MA, Musa N, Mohd Yasin MA, Lee YY, et al.
    Pain Ther, 2016 Jun;5(1):43-54.
    PMID: 26792136 DOI: 10.1007/s40122-016-0044-3
    INTRODUCTION: Methadone is a full agonist of the opioid receptor mu 1 which is encoded by the OPRM1 gene. Sleep disorders were frequently reported by opioid-dependent patients during methadone maintenance therapy (MMT). It is possible, therefore, that genetic polymorphisms in OPRM1 influence sleep quality among patients on MMT. This study investigated the association of OPRM1 polymorphisms with sleep quality among opioid-dependent patients on MMT.
    METHODS: The sleep quality of 165 male opioid-dependent patients receiving MMT was evaluated using the Pittsburgh Sleep Quality Index (PSQI). DNA was extracted from whole blood and subjected to polymerase chain reaction (PCR) genotyping.
    RESULTS: Patients with IVS2 + 691 CC genotype had higher PSQI scores [mean (SD) = 5.73 (2.89)] compared to those without the IVS2 + 691 CC genotype (IVS2 + 691 GG/GC genotype) [4.92 (2.31)], but the difference did not reach statistical significance (p = 0.081). Patients with combined 118 AA genotype and IVS2 + 691 GC genotype (AC/AG diplotype) had significantly lower PSQI scores [mean (SD) = 4.25 (2.27)] compared to those without the diplotype [5.68 (2.77)] (p = 0.018).
    CONCLUSION: Our study indicates that the AC/AG diplotype for the 118A>G and IVS2 + 691G>C polymorphisms of OPRM1 gene is associated with better sleep quality among males with opioid dependence on MMT.
    KEYWORDS: AC/AG diplotype; Male patients; Methadone; Methadone maintenance therapy; OPRM1; Opioid dependence; Opioid receptor; Opioid receptor, mu 1 gene; Pittsburgh Sleep Quality Index; Sleep quality
    Matched MeSH terms: Polymorphism, Genetic*
Filters
Contact Us

Please provide feedback to Administrator (afdal@afpm.org.my)

External Links