Displaying publications 2001 - 2020 of 10013 in total

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  1. Omar MN, Salleh AB, Lim HN, Ahmad Tajudin A
    Anal Biochem, 2016 09 15;509:135-141.
    PMID: 27402177 DOI: 10.1016/j.ab.2016.06.030
    Measurement of the uric acid level in the body can be improved by biosensing with respect to the accuracy, sensitivity and time consumption. This study has reported the immobilization of uricase onto graphene oxide (GO) and its function for electrochemical detection of uric acid. Through chemical modification of GO using 1-ethyl-3-(dimethylaminopropyl) carbodiimide (EDC) and N-hydroxysulfosuccinimide (NHS) as cross-linking reagents, the enzyme activity of the immobilized uricase was much comparable to the free enzyme with 88% of the activity retained. The modified GO-uricase (GOU) was then subjected to electrocatalytic detection of uric acid (UA) via cyclic voltammetry (CV). For that reason, a glassy carbon electrode (GCE) was modified by adhering the GO along with the immobilized uricase to facilitate the redox reaction between the enzyme and the substrate. The modified GOU/GCE outperformed a bare electrode through the electrocatalytic activity with an amplified electrical signal for the detection of UA. The electrocatalytic response showed a linear dependence on the UA concentration ranging from 0.02 to 0.49 mM with a detection limit of 3.45 μM at 3σ/m. The resulting biosensor also exhibited a high selectivity towards UA in the presence of other interference as well as good reproducibility.
  2. Mohd Nor NH, Berahim Z, Ahmad A, Kannan TP
    Curr Stem Cell Res Ther, 2017;12(1):52-60.
    PMID: 27538403
    Oral mucosa is a mucous membrane lining the oral cavity. Its main function is to protect the deeper structures against the external factors; thermal, chemical, mechanical and biological stimuli. Apart from that, it also plays a significant role during mastication, deglutition and speech. Some oral diseases or injuries to oral mucosa lead to impairment of the oral functions and aesthetics which eventually result in permanent defect of oral mucosa. In order to overcome this defect, different approaches for the development of reconstructed oral mucosa models have been employed including skin/autologous grafts, guided tissue replacement, vestibuloplasty etc. However, the finding of an acceptable source for the transplantations or autologous grafts seems a bit challenging. To overcome this problem, the development of oral mucosa using tissue engineering approach has been widely studied involving various cell lines from different sources. This paper aims to highlight various cell sources used in the development of tissueengineered oral mucosa models based on articles retrieved from PubMed and MEDLINE databases using the search terms "oral mucosa tissue engineering", regardless of time when published.
  3. Ahmad AR, Ismail SM, Zain RB, Mohamad Zaini Z
    Ann Dent, 2009;16(1):31-36.
    MyJurnal
    Langerhans Cell Histiocytosis (LCH) refers to a group of lesions presenting with a spectrum of clinical. features but sharing similar histology. These lesions are rare and treatment has been quite variable with current treatment protocol recommended being dependent on whether it is a unifocal or multi focal bone disease or a multi focal multisystem disease. However, the clinical presentations of LCH are variable and the decision to place into the appropriate clinical types may sometimes be masked by the non-discovery of all the lesions. In the oral maxillofacial area, the clinical features of these lesions may further pose a problem by nondescript manifestations as dental/periodontal/oral mucosal disorders. These oral findings may sometimes lead to inappropriate choice of treatment and delay in the diagnosis of all the lesions involved. This paper describes one such case where LCH manifest itself as a periodontal disease thus leading to delay in identifying all the sites involved and consequently a delay in id~ntifying the appropriate clinical type.
  4. Salleh WM, Ahmad F, Sirat HM, Yen KH
    EXCLI J, 2012;11:399-406.
    PMID: 27418915
    The essential oils obtained by hydrodistillation from the fresh leaf and stem of Piper porphyrophyllum N.E. Br. were analyzed by GC and GC/MS. Thirty four constituents were identified in the leaf oil, while thirty eight constituents were identified in the stems oil. The most abundant components in the leaf oil included bicyclogermacrene (14.7 %), α-copaene (13.2 %) and β-phellandrene (9.5 %) while sabinene (15.5 %), bicyclogermacrene (12.3 %) and α-copaene (8.1 %) were the main constituents in the stem oil. The evaluation of antibacterial activity by using micro-dilution method revealed that both oils were moderately active against all the Gram-positive bacteria (Staphylococcus aureus, Bacillus subtilis) and Gram-negative bacteria (Pseudomonas aeruginosa, Pseudomonas putida and Escherichia coli) with minimum inhibitory concentration (MIC) values in the range 125-1000 µg/ml.
  5. Mahmood MI, Shah SA, Ahmad N, Rosli NM
    J Cancer Educ, 2018 04;33(2):269-277.
    PMID: 27448613 DOI: 10.1007/s13187-016-1081-7
    The aim of this study was to demonstrate the construct validity of a newly developed cancer screening perception scale as a measure of the perception of cancer screening in general among high-risk but healthy asymptomatic groups.The cancer screening perception scale (CSPS) was developed based on extensive literature reviews guided by The Health Belief Model. Fifty-five written items were initially pooled, reviewed by experts for face validity, pretested by 25 healthcare workers and translated into Malay using simple back translation. The scale was then distributed to 300 respondents from two health clinics for construct validation purposes. The obtained data were analyzed using the varimax rotation method for exploratory factor analysis (EFA). The data was submitted for further confirmatory factor analysis using AMOS software.Based on EFA, the results produced five constructs as predicted: perceived severity, perceived susceptibility, perceived benefits, perceived barriers, and cues for action. Two items with low factor loading and unrelated to the recovered domains were removed. Perceived barriers and cues for action had three and two sub-domains respectively which were further confirmed to fit the measurement and structural models. CFA demonstrated the scale fitted GFI = 0.936, CFI = 0.935, RMSEA = 0.076, NORMEDCHISQ = 2.162. The scale discriminated between the domains. Cronbach's alpha for perceived severity, perceived susceptibility, perceived benefits, perceived barrier, and cues for action were 0.907, 0.877, 0.940, 0.864 and 0.938, respectively.The cancer screening perception scale with its promising psychometric properties is now available to measure risks to high-risk but healthy, asymptomatic groups aged 18 and above and can also be used for larger scale study purposes.
  6. Yam MF, Tan CS, Ahmad M, Shibao R
    Eur J Pharmacol, 2016 Oct 15;789:27-36.
    PMID: 27370961 DOI: 10.1016/j.ejphar.2016.06.047
    Previous studies demonstrated that eupatorin content in Orthosiphon stamineus fractions correlated with their vasorelaxation activity. Even with previous studies, there is still very little information on the vasorelaxation effect of eupatorin, and not many scientific studies had been carried out. Therefore, the present study was designed to investigate the vasorelaxation activity and mechanism of action of eupatorin. The vasorelaxation activity and the underlying mechanisms of eupatorin was evaluated on thoracic aortic rings isolated from Sprague Dawley rats. Eupatorin caused the relaxation of aortic rings pre-contracted with phenylephrine with and without endothelium (pD2=6.66±0.13, EMAX=99.72±6.39%; pD2=6.10±0.22, EMAX=65.78±8.01%), and also the relaxation of endothelium-intact aortic rings pre-contracted with potassium chloride (pD2=6.20±0.30, EMAX=71.89±12.25%). In the presence of Nω-nitro-l-arginine methyl ester (pD2<4.60, EMAX=24.91±6.39%), methylene blue (pD2=6.05±0.38, EMAX=66.79±9.69%), ODQ (pD25.84±0.32, EMAX=60.47±9.6%), indomethacin (pD2=6.27±0.21, EMAX=76.03±9.45%), tetraethylammonium (pD2=6.09±0.35, EMAX=69.35±11.31%), 4-aminopyridine (pD2=6.34±0.12, EMAX=76±6.1%), barium chloride (pD2=6.47±0.14, EMAX=79.61±10.02%), atropine (pD2=6.36±0.29, EMAX=86.47±12.95%) and propranolol (pD2=6.49±0.26, EMAX=83.2±12.01%), relaxation stimulated by eupatorin was significantly reduced. Eupatorin was also found to be active in reducing Ca(2+) release from sarcoplasmic reticulum and in blocking calcium channels. The present study demonstrates the vasorelaxation effect of eupatorin involving NO/sGC/cGMP and indomethacin pathways, calcium and potassium channels, and muscarinic and beta-adrenergic receptors.
  7. Sha'ari N, Manaf ZA, Ahmad M, Rahman FN
    Pediatr Int, 2017 Apr;59(4):408-415.
    PMID: 27805287 DOI: 10.1111/ped.13196
    BACKGROUND: Children with attention deficit-hyperactivity disorder (ADHD) may be at risk of nutrient deficiency due to the inability to sit through meals. This comparative cross-sectional study was therefore carried out to determine the nutritional status and feeding problems of ADHD children aged 4-12 years.

    METHODS: Sociodemographic data, anthropometric measurements and 3 day dietary intake record were collected from 54 ADHD children and 54 typical development (TD) children. The Behavioral Pediatrics Feeding Assessment Scale was used to assess feeding problems.

    RESULTS: Mean subject age was 8.6 ± 2.1 years. On anthropometric assessment, 11.1% of the ADHD children had wasting, while 1.9% had severe wasting. In contrast, none of the TD children had wasting. Approximately 5.6% of the ADHD children had stunting, as compared with 3.7% of the TD children, while none of the TD children had severe stunting compared with 3.7% of the ADHD children. More than half of the ADHD children had mid-upper arm circumference (MUAC) below the 5th percentile, indicating undernutrition, compared with only 35.2% of TD children. More than one-third of the ADHD children had feeding problems compared with 9.3% of TD children. There was a significant negative relationship between the ADHD children's feeding problems and bodyweight (r = -0338, P = 0.012), body mass index (r = -0322, P = 0.017) and MUAC (r = -0384, P = 0.004).

    CONCLUSION: Almost half of the ADHD children had suboptimal nutrition compared with 11.1% of the TD children. It is imperative to screen ADHD children for nutritional status and feeding problems to prevent negative health impacts later on.

  8. Zakaria R, Wan Yaacob WM, Othman Z, Long I, Ahmad AH, Al-Rahbi B
    Physiol Res, 2017 09 22;66(4):553-565.
    PMID: 28406691
    Alzheimer's disease (AD) is a primary cause of dementia in the middle-aged and elderly worldwide. Animal models for AD are widely used to study the disease mechanisms as well as to test potential therapeutic agents for disease modification. Among the non-genetically manipulated neuroinflammation models for AD, lipopolysaccharide (LPS)-induced animal model is commonly used. This review paper aims to discuss the possible factors that influence rats' response following LPS injection. Factors such as dose of LPS, route of administration, nature and duration of exposure as well as age and gender of animal used should be taken into account when designing a study using LPS-induced memory impairment as model for AD.
  9. Pariyani R, Ismail IS, Ahmad Azam A, Abas F, Shaari K
    J Sci Food Agric, 2017 Sep;97(12):4169-4179.
    PMID: 28233369 DOI: 10.1002/jsfa.8288
    BACKGROUND: Java tea is a well-known herbal infusion prepared from the leaves of Orthosiphon stamineus (OS). The biological properties of tea are in direct correlation with the primary and secondary metabolite composition, which in turn largely depends on the choice of drying method. Herein, the impact of three commonly used drying methods, i.e. shade, microwave and freeze drying, on the metabolite composition and antioxidant activity of OS leaves was investigated using proton nuclear magnetic resonance (1 H NMR) spectroscopy combined with multivariate classification and regression analysis tools.

    RESULTS: A total of 31 constituents comprising primary and secondary metabolites belonging to the chemical classes of fatty acids, amino acids, sugars, terpenoids and phenolic compounds were identified. Shade-dried leaves were identified to possess the highest concentrations of bioactive secondary metabolites such as chlorogenic acid, caffeic acid, luteolin, orthosiphol and apigenin, followed by microwave-dried samples. Freeze-dried leaves had higher concentrations of choline, amino acids leucine, alanine and glutamine and sugars such as fructose and α-glucose, but contained the lowest levels of secondary metabolites.

    CONCLUSION: Metabolite profiling coupled with multivariate analysis identified shade drying as the best method to prepare OS leaves as Java tea or to include in traditional medicine preparation. © 2017 Society of Chemical Industry.

  10. Shaharuddin B, Ahmad S, Md Latar N, Ali S, Meeson A
    Stem Cells Transl Med, 2017 03;6(3):761-766.
    PMID: 28297580 DOI: 10.5966/sctm.2016-0175
    Limbal stem cell (LSC) deficiency is a visually debilitating condition caused by abnormal maintenance of LSCs. It is treated by transplantation of donor-derived limbal epithelial cells (LECs), the success of which depends on the presence and quality of LSCs within the transplant. Understanding the immunobiological responses of these cells within the transplants could improve cell engraftment and survival. However, human corneal rings used as a source of LSCs are not always readily available for research purposes. As an alternative, we hypothesized that a human telomerase-immortalized corneal epithelial cell (HTCEC) line could be used as a model for studying LSC immunobiology. HTCEC constitutively expressed human leukocyte antigen (HLA) class I but not class II molecules. However, when stimulated by interferon-γ, HTCECs then expressed HLA class II antigens. Some HTCECs were also migratory in response to CXCL12 and expressed stem cell markers, Nanog, Oct4, and Sox2. In addition because both HTCECs and LECs contain side population (SP) cells, which are an enriched LSC population, we used these SP cells to show that some HTCEC SP cells coexpressed ABCG2 and ABCB5. HTCEC SP and non-side population (NSP) cells also expressed CXCR4, but the SP cells expressed higher levels. Both were capable of colony formation, but the NSP colonies were smaller and contained fewer cells. In addition, HTCECs expressed ΔNp63α. These results suggest the HTCEC line is a useful model for further understanding LSC biology by using an in vitro approach without reliance on a supply of human tissue. Stem Cells Translational Medicine 2017;6:761-766.
  11. Misron K, Hamid SSA, Ahmad A, Ramli RR
    Clin Exp Otorhinolaryngol, 2017 Sep;10(3):241-247.
    PMID: 28449554 DOI: 10.21053/ceo.2016.01732
    OBJECTIVES: This case-controlled study aimed to identify the association of tumor necrosis factor (TNF)α-1031 and TNFβ+ 252 gene polymorphisms between chronic rhinosinusitis (CRS) and healthy controls. Another purpose of this study was to investigate the associations of these gene polymorphisms with factors related to CRS.

    METHODS: All deoxyribonucleic acid (DNA) samples were genotyped for TNFα-1031 and TNFβ+252 genes by mean of polymerase chain reaction (PCR) and restriction fragment length polymorphisms (RFLP). The statistical analysis were carried out using chi-square test or Fisher exact test to determine the associations of these gene polymorphisms in CRS. Multiple logistic regression was performed to evaluate the associations of these gene polymorphisms in CRS and its related risk factors.

    RESULTS: The genotype and allele frequencies of TNFα-1031 and TNFβ+252 gene did not show any significant associations between CRS and healthy controls. However, a significantly statistical difference of TNFα-1031 was observed in CRS participants with atopy (P-value, 0.045; odds ratio, 3.66) but not in CRS with asthma or aspirin intolerance.

    CONCLUSION: Although the presence of TNFα-1031 and TNFβ+252 gene polymorphisms did not render any significant associations between CRS and healthy control, this study suggests that TNFα-1031 gene polymorphisms in CRS patients with atopy may be associated with increase susceptibility towards CRS.

  12. Buttery JE, de Witt GF, Ahmad UO
    Med J Malaya, 1969 Jun;23(4):265-8.
    PMID: 4242173
  13. Anuar R, Mohd-Hisyamudin HP, Ahmad MH, Zulkiflee O
    Malays Orthop J, 2015 Nov;9(3):40-43.
    PMID: 28611908 MyJurnal DOI: 10.5704/MOJ.1511.006
    Delayed presentation of Developmental Dysplasia of Hip (DDH) comes with challenges in treatment as well as high surgical cost. Therefore the objective of this study is to quantify the economic impact of management of late presentation of DDH during a last 3-year period. We conducted a retrospective study with analysis of DDH cases managed between years 2012 to 2014. Early and late presentations of DDH were identified and cost management for both was estimated. Out of twenty-four DDH cases, thirteen cases fulfilled the inclusion criteria. All were female with majority of them presenting with unilateral DDH predominantly of the left hip. Most patients presented after age of six months and the principal complaint was abnormal or limping gait. The grand total cost for managing DDH during the three years period was USD 12,385.51, with 86% of the amount having been used to manage late presentation of DDH that was mostly contributed by the cost of surgery. We concluded that delayed presentation of DDH contributes heavily to high national expenditure. Early detection of DDH cases with systematic neonatal screening may help to minimize the incidence of the late presenting DDH and subsequently reduce the economic burden to the government.
  14. Nikmat AW, Ahmad M, Ng LO, Razali S
    ASEAN Journal of Psychiatry, 2008;9(2):65-72.
    MyJurnal
    Objective: To investigate the prevalence of parental stress and psychological wellbeing among parents with autistic children and their associations with dimensions of support system.
    Methods: This is a preliminary cross sectional study which randomly selected parents with clinically diagnosed autistic children. Those parents who attended psycho-education session on management of autistic children at Health Psychology Unit were randomly selected to enroll in the study. Psychological wellbeing, parental stress and dimensions of support system were assessed by using the General Health Questionnaire (GHQ-28), the Parenting Stress Index (PSI) and the Provision Social Relation (PSR), respectively.
    Results: Of 52 parents with autistic children (34 female and 18 male), about 90.4% of parents had significant parenting stress, and 53.8% of parents showed clinical disturbance in psychological wellbeing. Gender (t=1.67, p=0.02) and occupation (F=4.78, p=0.01) showed statistically significant association with psychological wellbeing. No association found between other socio-demographic factors, parental stress and psychological wellbeing with dimensions of support system among parents with autistic children.
    Conclusion: Parents with autistic children have high prevalence of stress and psychological disturbances. Interactions of various factors need to be acknowledged and considered in order to reduce the burden of parents with autistic children.
  15. Buttery JE, De Witt GF, Ahmad UO
    Med J Malaya, 1968 Mar;22(3):217-21.
    PMID: 4234358
  16. Buttery JE, de Witt GF, Ahmad UO
    Med J Malaya, 1967 Jun;21(4):362-5.
    PMID: 4230505
  17. Ramanathan K, Jin LE, Keat TC, Omar-Ahmad DU
    Dent J Malaysia Singapore, 1970 May;10(1):15-34.
    PMID: 5271011
  18. Che Ahmad Tantowi NA, Lau SF, Mohamed S
    Calcif. Tissue Int., 2018 10;103(4):388-399.
    PMID: 29808374 DOI: 10.1007/s00223-018-0433-1
    Osteoporosis (OP) and osteoarthritis (OA) are debilitating musculoskeletal diseases of the elderly. Ficus deltoidea (FD) or mistletoe fig, a medicinal plant, was pre-clinically evaluated against OP- and OA-related bone alterations, in postmenopausal OA rat model. Thirty twelfth-week-old female rats were divided into groups (n = 6). Four groups were bilateral ovariectomized (OVX) and OA-induced by intra-articular monosodium iodoacetate (MIA) injection into the right knee joints. The Sham control and OVX-OA non-treated groups were given deionized water. The three other OVX-OA groups were orally administered daily with FD extract (200, 400 mg/kg) or diclofenac (5 mg/kg) for 4 weeks. The rats' bones and blood were evaluated for protein and mRNA expressions of osteoporosis and inflammatory indicators, and micro-CT computed tomography for bone microstructure. The non-treated OVX-OA rats developed severe OP bone loss and bone microstructural damage in the subchondral and metaphyseal regions, supported by reduced serum bone formation markers (osteocalcin, osteoprotegerin) and increased bone resorption markers (RANKL and CTX-I). The FD extract significantly (p 
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