Displaying publications 1 - 20 of 212 in total

  1. Tiong, C.P., Loke, A.C., Mohamed, Z., Zainal, N.Z.
    Objective: This study investigates the relationship between antidepressant response to escitalopram and polymorphism of the serotonin transporter gene promoter region (5-HTTLPR) in multi ethnic Malaysian patients with Major Depressive Disorder. Methods: An eight weeks prospective study of treatment response to escitalopram was conducted on 29 Malaysian patients with Major Depressive Disorder. The severity and improvement of depression were assessed with the Montgomery-Asberg Depression Rating Scale. Patients were also genotyped for long (L) and short (S) polymorphisms in 5-HTTLPR using polymerase chain reaction. Results: Response to escitalopram treatment was more frequent in patients with 5-HTTLPR SS genotype than in those with LL or LS genotypes (p = 0.04, OR = 10.0, 95% CI = 1.05-95.2). The favourable allelic variant for response was S allele (p
  2. Subramaniam, K.S., Wong, M.S., Woo, Y.L., Mat Adenan, N.A., Mohamed, Z., Chung, I., et al.
    JUMMEC, 2013;16(1):1-5.
    Genetic mutations in endometrial cancer (EC) have been extensively studied in the Western population but not much in Asian cohorts. This study has demonstrated that PTEN and PIK3CA mutations are commonly found in EC among Malaysian women. Following RNA extraction from 20 cancerous and 18 non-cancerous tissues, the presence of mutations in 9 exons of PTEN and 3 exons of PIK3CA genes were detected using real-time PCR, accompanied by High Resolution Melt (HRM) analysis. Sequencing confirmed specificity of each PCR product. The mutations for both genes were detected in the samples with varying frequencies. Notably, all samples expressed mutation of PTEN at exon 7 but none in exon 4. Further analysis demonstrated that strong concurrent mutations occurred between exons 7 of PTEN with exon 20 region 1 of PIK3CA gene (90%). Our data showed mutations are present in EC and not the non-cancerous tissues. Larger samples are being collected to validate this observation.
  3. Apalasamy YD, Mohamed Z
    Hum. Genet., 2015 Apr;134(4):361-74.
    PMID: 25687726 DOI: 10.1007/s00439-015-1533-x
    Obesity is a complex and multifactorial disease that occurs as a result of the interaction between "obesogenic" environmental factors and genetic components. Although the genetic component of obesity is clear from the heritability studies, the genetic basis remains largely elusive. Successes have been achieved in identifying the causal genes for monogenic obesity using animal models and linkage studies, but these approaches are not fruitful for polygenic obesity. The developments of genome-wide association approach have brought breakthrough discovery of genetic variants for polygenic obesity where tens of new susceptibility loci were identified. However, the common SNPs only accounted for a proportion of heritability. The arrival of NGS technologies and completion of 1000 Genomes Project have brought other new methods to dissect the genetic architecture of obesity, for example, the use of exome genotyping arrays and deep sequencing of candidate loci identified from GWAS to study rare variants. In this review, we summarize and discuss the developments of these genetic approaches in human obesity.
  4. Islam MM, Mohamed Z
    Biomed Res Int, 2015;2015:731292.
    PMID: 26579539 DOI: 10.1155/2015/731292
    The blood-brain barrier (BBB) is a dynamic and highly selective permeable interface between central nervous system (CNS) and periphery that regulates the brain homeostasis. Increasing evidences of neurological disorders and restricted drug delivery process in brain make BBB as special target for further study. At present, neurovascular unit (NVU) is a great interest and highlighted topic of pharmaceutical companies for CNS drug design and delivery approaches. Some recent advancement of pharmacology and computational biology makes it convenient to develop drugs within limited time and affordable cost. In this review, we briefly introduce current understanding of the NVU, including molecular and cellular composition, physiology, and regulatory function. We also discuss the recent technology and interaction of pharmacogenomics and bioinformatics for drug design and step towards personalized medicine. Additionally, we develop gene network due to understand NVU associated transporter proteins interactions that might be effective for understanding aetiology of neurological disorders and new target base protective therapies development and delivery.
  5. Asiah K, Hanifah YA, Norzila MZ, Hasniah L, Rusanida A
    J Paediatr Child Health, 2006 Apr;42(4):217-8.
    PMID: 16630326
    We report a 17-year-old Malay boy with cystic fibrosis who over a 14-month period experienced worsening respiratory symptoms and deteriorating lung function. Burkholderia pseudomallei was eventually isolated from his sputum. He improved clinically following treatment for meliodosis and his lung function returned to normal.
  6. Islam MM, Aktaruzzaman M, Mohamed Z
    Bioinformation, 2015;11(2):67-72.
    PMID: 25848166 DOI: 10.6026/97320630011067
    Normal blood glucose level depends on the availability of insulin and its ability to bind insulin receptor (IR) that regulates the downstream signaling pathway. Insulin sequence and blood glucose level usually vary among animals due to species specificity. The study of genetic variation of insulin, blood glucose level and diabetics symptoms development in Aves is interesting because of its optimal high blood glucose level than mammals. Therefore, it is of interest to study its evolutionary relationship with other mammals using sequence data. Hence, we compiled 32 Aves insulin from GenBank to compare its sequence-structure features with phylogeny for evolutionary inference. The analysis shows long conserved motifs (about 14 residues) for functional inference. These sequences show high leucine content (20%) with high instability index (>40). Amino acid position 11, 14, 16 and 20 are variable that may have contribution to binding to IR. We identified functionally critical variable residues in the dataset for possible genetic implication. Structural models of these sequences were developed for surface analysis towards functional representation. These data find application in the understanding of insulin function across species.
  7. Mohamed Z, Newton JM, McKenna L
    Int Nurs Rev, 2014 Mar;61(1):124-30.
    PMID: 24512262 DOI: 10.1111/inr.12078
    The need to belong has been proposed as the most basic need for human psychological well-being. Lack of belongingness has been associated with stress, anxiety and lack of esteem. Social and psychological functioning in the workplace has been linked to nurses' interconnection with others and their perceptions of belongingness.
  8. Basuni M, Mohamed Z, Ahmad M, Zakaria NZ, Noordin R
    Trop Biomed, 2012 Sep;29(3):434-42.
    PMID: 23018507
    Intestinal parasites are the causative agents of a number of important human infections in developing countries. The objective of this study was to determine the prevalence of selected helminths and protozoan infections among patients admitted with gastrointestinal disorders at Hospital Universiti Sains Malaysia, Kelantan, Malaysia using multiplex real-time PCR. In addition microscopic examination was also performed following direct smear, zinc sulphate concentration and Kato-Katz thick smear techniques; and the presence of protozoan parasites was confirmed using trichrome and acid-fast stains. Of the 225 faecal samples analysed, 26.2% were positive for intestinal parasites by the multiplex real-time PCR, while 5.3% were positive by microscopy. As compared to microscopy, the multiplex real-time PCR detected 5.8 and 4.5 times more positives for the selected helminth and protozoan infections respectively. Among the selected helminths detected in this study, hookworm was the most prevalent by real-time PCR, while Ascaris lumbricoides was detected the most by microscopy. Meanwhile, among the selected protozoa detected in this study, Entamoeba histolytica was the most prevalent by real-time PCR, however microscopy detected equal number of cases with E. histolytica and Giardia lamblia. This study showed that real-time PCR can be used to obtain a more accurate prevalence data on intestinal helminths and protozoa.
  9. Abdul-Nasir AS, Mashor MY, Mohamed Z
    Comput Math Methods Med, 2012;2012:637360.
    PMID: 23082089 DOI: 10.1155/2012/637360
    Malaria is one of the serious global health problem, causing widespread sufferings and deaths in various parts of the world. With the large number of cases diagnosed over the year, early detection and accurate diagnosis which facilitates prompt treatment is an essential requirement to control malaria. For centuries now, manual microscopic examination of blood slide remains the gold standard for malaria diagnosis. However, low contrast of the malaria and variable smears quality are some factors that may influence the accuracy of interpretation by microbiologists. In order to reduce this problem, this paper aims to investigate the performance of the proposed contrast enhancement techniques namely, modified global and modified linear contrast stretching as well as the conventional global and linear contrast stretching that have been applied on malaria images of P. vivax species. The results show that the proposed modified global and modified linear contrast stretching techniques have successfully increased the contrast of the parasites and the infected red blood cells compared to the conventional global and linear contrast stretching. Hence, the resultant images would become useful to microbiologists for identification of various stages and species of malaria.
  10. Pandy V, Narasingam M, Mohamed Z
    PMID: 23082808 DOI: 10.1186/1472-6882-12-186
    Noni fruit is widely consumed in tropical regions of Indonesia to the Hawaiian Islands. The noni plant has a long history of use as a medicinal plant to treat a wide variety of ailments including CNS disorders. The present investigation was designed to evaluate the antipsychotic effect of noni fruits (Morinda citrifolia Linn.) using mouse models of apomorphine-induced climbing behaviour and methamphetamine-induced stereotypy (licking, biting, gnawing and sniffing).
  11. Teh SH, Fong MY, Mohamed Z
    Genet. Mol. Biol., 2011 Jul;34(3):464-70.
    PMID: 21931521 DOI: 10.1590/S1415-47572011005000022
    The Pichia pastoris expression system was used to produce recombinant human erythropoietin, a protein synthesized by the adult kidney and responsible for the regulation of red blood cell production. The entire recombinant human erythropoietin (rhEPO) gene was constructed using the Splicing by Overlap Extension by PCR (SOE-PCR) technique, cloned and expressed through the secretory pathway of the Pichia expression system. Recombinant erythropoietin was successfully expressed in P. pastoris. The estimated molecular mass of the expressed protein ranged from 32 kDa to 75 kDa, with the variation in size being attributed to the presence of rhEPO glycosylation analogs. A crude functional analysis of the soluble proteins showed that all of the forms were active in vivo.
  12. Yeng C, Osman E, Mohamed Z, Noordin R
    Electrophoresis, 2010 Dec;31(23-24):3843-9.
    PMID: 21080484 DOI: 10.1002/elps.201000038
    Toxoplasma gondii infection in pregnant women may result in abortion and foetal abnormalities, and may be life-threatening in immunocompromised hosts. To identify the potential infection markers of this disease, 2-DE and Western blot methods were employed to study the parasite circulating antigens and host-specific proteins in the sera of T. gondii-infected individuals. The comparisons were made between serum protein profiles of infected (n=31) and normal (n=10) subjects. Antigenic proteins were identified by immunoblotting using pooled sera and monoclonal anti-human IgM-HRP. Selected protein spots were characterised using mass spectrometry. Prominent differences were observed when serum samples of T. gondii-infected individuals and normal controls were compared. A significant up-regulation of host-specific proteins, α(2)-HS glycoprotein and α(1)-B glycoprotein, was also observed in the silver-stained gels of both active and chronic infections. However, only α(2)-HS glycoprotein and α(1)-B glycoprotein in the active infection showed immunoreactivity in Western blots. In addition, three spots of T. gondii proteins were detected, namely (i) hypothetical protein chrXII: 3984434-3 TGME 49, (ii) dual specificity protein phosphatase, catalytic domain TGME 49 and (iii) NADPH-cytochrome p450 reductase TGME 49. Thus, 2-DE approach followed by Western blotting has enabled the identification of five potential infection markers for the diagnosis of toxoplasmosis: three are parasite-specific proteins and two are host-specific proteins.
  13. Tan SH, Mohd Aris E, Kurahashi H, Mohamed Z
    Trop Biomed, 2010 Aug;27(2):287-93.
    PMID: 20962727
    Iranihindia martellata (Senior-White, 1924) is recorded from peninsular Malaysia for the first time. Male and female specimens in the recent collections of forensically important sarcophagid flies were examined and identified based on morphology and DNA sequencing analysis. Male genitalia offer unambiguous species identification characteristics in the traditional taxonomy of flesh flies but the female flies are very similar to one another in general morphology. Female of I. martellata was determined by DNA sequencing (COI and COII) and PCR-RFLP (COI) analysis. Identified females were carefully examined and compared with the morphologically similar species, Liopygia ruficornis (Fabricius, 1794). Female genitalia are re-described and illustrated in this paper.
  14. Achanna S, Mohamed Z, Krishnan M
    J. Obstet. Gynaecol. Res., 2006 Jun;32(3):341-5.
    PMID: 16764627
    Acute puerperal uterine inversion is a life-threatening and unpredictable obstetric emergency. If overlooked, it could lead to a maternal death. Although the precise cause is unknown, it is postulated to be caused by the mismanagement of the third stage of labor with premature traction of the umbilical cord and fundal pressure before placental separation. At the Ipoh General Hospital in Malaysia there were 31 394 deliveries and four acute uterine inversions occurring from 1 January 2002 to 30 June 2005. The four patients were between 25 and 36 years of age and their parities were between two and three. When manual repositioning of the uterus failed, successful correction was accomplished by the O'Sullivan's hydrostatic method. One case had to undergo subtotal hysterectomy after repositioning because of massive hemorrhage secondary to placenta accreta. Early diagnosis, immediate treatment of shock, and replacement are essential.
  15. Phua AC, Abdullah RB, Mohamed Z
    J. Reprod. Dev., 2003 Aug;49(4):307-11.
    PMID: 14967923
    Sex determination of livestock is performed to achieve the objectives of livestock breeding programmes. Techniques for sex determination have evolved from karyotyping to detecting Y-specific antigens and recently to the polymerase chain reaction (PCR), which appears to be the most sensitive, accurate, rapid and reliable method to date. In this study, a PCR-based sex determination method for potential application in goat breeding programmes was developed. Primers were designed to amplify a portion of the X amelogenin gene (Aml-X) on the X chromosome to give a 300 bp product and Sry gene on the Y chromosome to give a 116 bp product. PCR optimization was performed using DNA template extracted from a whole blood sample of Jermasia goats (German Fawn x Katjang) of both sexes. It was possible to identify the sex chromosomes by amplifying both male- and female-specific genes simultaneously in a duplex reaction with males yielding two bands and females yielding one band. The Aml-X primer set, which served as an internal control primer, did not interfere with amplification of the Y-specific sequence even when a low amount of DNA (1 ng) was used. The duplex reaction subjected to a blind test showed 100% (14/14) concordance, proving its accuracy and reliability. The primer sets used were found to be highly specific and were suitable for gender selection of goats.
  16. Arief EM, Mohamed Z, Idris FM
    Cleft Palate Craniofac. J., 2005 May;42(3):277-9.
    PMID: 15865462
    OBJECTIVE: To determine the effect of surgery on types and colony count of Streptococcus and Staphylococcus species in cleft lip and palate (CLP) patients.

    DESIGN: Saliva samples were collected after the morning meal by placing a sterile cotton swab in the vestibule of the oral cavity from cleft lip and palate patients immediately preoperative and 12 weeks postoperative. Normal children were examined as a control group. Samples were cultured; Staphylococcus and Streptococcus isolates were identified and quantified.

    PATIENTS: Fifteen cleft lip and palate patients and 22 normal children, aged 3 to 39 months were examined.

    RESULTS: Streptococcus mitis biovar 1, Streptococcus salivarius and Streptococcus oralis of the viridans group of streptococci were the most commonly found in normal children, as well as in cleft lip and palate children. In the cleft lip and palate group, mean streptococcal count was 32.41 (29.80) and 46.46 (42.80) in the pre- and postoperative periods, respectively; in the normal group, the count was 20.93 (27.93) and 49.92 (34.72) at 0 week and 12 weeks, respectively. Staphylococcus aureus was the most common Staphylococcus species found in CLP patients, representing 47.4% postoperatively. In the cleft lip and palate children, mean staphylococcal count was 5.34 (8.13) and 0.56 (0.92) in the pre- and postoperative periods, respectively; in normal children, the count was 0.82 (1.98) and 0.60 (2.55) at 0 and 12 weeks, respectively. The differences were statistically significant only for the staphylococcal count between pre- and postoperative periods in children with cleft lip and palate as tested by analysis of variance (p < .05).

    CONCLUSIONS: Cleft lip and palate patients had more colonization by S. aureus compared with normal children, and the colony count decreased significantly following surgical repair of the cleft lip and palate.

  17. Islam M, Mohamed Z, Assenov Y
    Int J Genomics, 2017;2017:2913648.
    PMID: 28713819 DOI: 10.1155/2017/2913648
    Acute myeloid leukemia (AML) is a haematological malignancy characterized by the excessive proliferation of immature myeloid cells coupled with impaired differentiation. Many AML cases have been reported without any known cytogenetic abnormalities and carry no mutation in known AML-associated driver genes. In this study, 200 AML cases were selected from a publicly available cohort and differentially analyzed for genetic, epigenetic, and cytogenetic abnormalities. Three genes (FLT3, DNMT3A, and NPMc) are found to be predominantly mutated. We identified several aberrations to be associated with genome-wide methylation changes. These include Del (5q), T (15; 17), and NPMc mutations. Four aberrations-Del (5q), T (15; 17), T (9; 22), and T (9; 11)-are significantly associated with patient survival. Del (5q)-positive patients have an average survival of less than 1 year, whereas T (15; 17)-positive patients have a significantly better prognosis. Combining the methylation and mutation data reveals three distinct patient groups and four clusters of genes. We speculate that combined signatures have the better potential to be used for subclassification of AML, complementing cytogenetic signatures. A larger sample cohort and further investigation of the effects observed in this study are required to enable the clinical application of our patient classification aided by DNA methylation.
  18. Chellian R, Pandy V, Mohamed Z
    Phytomedicine, 2017 Aug 15;32:41-58.
    PMID: 28732807 DOI: 10.1016/j.phymed.2017.04.003
    BACKGROUND: Asarone is one of the most researched phytochemicals and is mainly present in the Acorus species and Guatteria gaumeri Greenman. In preclinical studies, both α- and β-asarone have been reported to have numerous pharmacological activities and at the same time, many studies have also revealed the toxicity of α- and β-asarone.

    PURPOSE: The purpose of this comprehensive review is to compile and analyze the information related to the pharmacokinetic, pharmacological, and toxicological studies reported on α- and β-asarone using preclinical in vitro and in vivo models. Besides, the molecular targets and mechanism(s) involved in the biological activities of α- and β-asarone were discussed.

    METHODS: Databases including PubMed, ScienceDirect and Google scholar were searched and the literature from the year 1960 to January 2017 was retrieved using keywords such as α-asarone, β-asarone, pharmacokinetics, toxicology, pharmacological activities (e.g. depression, anxiety).

    RESULTS: Based on the data obtained from the literature search, the pharmacokinetic studies of α- and β-asarone revealed that their oral bioavailability in rodents is poor with a short plasma half-life. Moreover, the metabolism of α- and β-asarone occurs mainly through cytochrome-P450 pathways. Besides, both α- and/or β-asarone possess a wide range of pharmacological activities such as antidepressant, antianxiety, anti-Alzheimer's, anti-Parkinson's, antiepileptic, anticancer, antihyperlipidemic, antithrombotic, anticholestatic and radioprotective activities through its interaction with multiple molecular targets. Importantly, the toxicological studies revealed that both α- and β-asarone can cause hepatomas and might possess mutagenicity, genotoxicity, and teratogenicity.

    CONCLUSIONS: Taken together, further preclinical studies are required to confirm the pharmacological properties of α-asarone against depression, anxiety, Parkinson's disease, psychosis, drug dependence, pain, inflammation, cholestasis and thrombosis. Besides, the anticancer effect of β-asarone should be further studied in different types of cancers using in vivo models. Moreover, further dose-dependent in vivo studies are required to confirm the toxicity of α- and β-asarone. Overall, this extensive review provides a detailed information on the preclinical pharmacological and toxicological activities of α-and β-asarone and this could be very useful for researchers who wish to conduct further preclinical studies using α- and β-asarone.

  19. Chellian R, Pandy V, Mohamed Z
    Eur. J. Pharmacol., 2018 Jan 05;818:10-16.
    PMID: 29042206 DOI: 10.1016/j.ejphar.2017.10.025
    In the present study, the effect α-asarone on nicotine withdrawal-induced depression-like behavior in mice was investigated. In this study, mice were exposed to drinking water or nicotine solution (10-200µg/ml) as a source of drinking for forty days. During this period, daily fluid consumption, food intake and body weight were recorded. The serum cotinine level was estimated before nicotine withdrawal. Naïve mice or nicotine-withdrawn mice were treated with α-asarone (5, 10 and 20mg/kg, i.p.) or bupropion (10mg/kg, i.p.) for eight consecutive days and the forced swim test (FST) or locomotor activity test was conducted. In addition, the effect of α-asarone or bupropion on the hippocampal pCREB, CREB and BDNF levels during nicotine-withdrawal were measured. Results indicated that α-asarone (5, 10 and 20mg/kg, i.p.) or bupropion (10mg/kg, i.p.) pretreatment did not significantly alter the immobility time in the FST or spontaneous locomotor activity in naïve mice. However, the immobility time of nicotine-withdrawn mice was significantly attenuated with α-asarone (5, 10 and 20mg/kg, i.p.) or bupropion (10mg/kg, i.p.) pretreatment in the FST. Besides, α-asarone (5, 10 and 20mg/kg, i.p.) or bupropion (10mg/kg, i.p.) pretreatment significantly attenuated the hippocampal pCREB levels in nicotine-withdrawn mice. Overall, the present results indicate that α-asarone treatment attenuated the depression-like behavior through the modulation of hippocampal pCREB levels during nicotine-withdrawal in mice.
  20. Hajissa K, Zakaria R, Suppian R, Mohamed Z
    BMC Infect. Dis., 2017 12 29;17(1):807.
    PMID: 29284420 DOI: 10.1186/s12879-017-2920-9
    BACKGROUND: The inefficiency of the current tachyzoite antigen-based serological assays for the serodiagnosis of Toxoplasma gondii infection mandates the need for acquirement of reliable and standard diagnostic reagents. Recently, epitope-based antigens have emerged as an alternative diagnostic marker for the achievement of highly sensitive and specific capture antigens. In this study, the diagnostic utility of a recombinant multiepitope antigen (USM.TOXO1) for the serodiagnosis of human toxoplasmosis was evaluated.

    METHODS: An indirect enzyme-linked immunosorbent assay (ELISA) was developed to evaluate the usefulness of USM.TOXO1 antigen for the detection of IgG antibodies against Toxoplasma gondii in human sera. Whereas the reactivity of the developed antigen against IgM antibody was evaluated by western blot and Dot enzyme immunoassay (dot-EIA) analysis.

    RESULTS: The diagnostic performance of the new antigens in IgG ELISA was achieved at the maximum values of 85.43% and 81.25% for diagnostic sensitivity and specificity respectively. The USM.TOXO1 was also proven to be reactive with anti- T. gondii IgM antibody.

    CONCLUSIONS: This finding makes the USM.TOXO1 antigen an attractive candidate for improving the toxoplasmosis serodiagnosis and demonstrates that multiepitope antigens could be a potential and promising diagnostic marker for the development of high sensitive and accurate assays.

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