Displaying publications 3821 - 3840 of 8055 in total

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  1. Jamal N, Ng KH, Looi LM, McLean D, Zulfiqar A, Tan SP, et al.
    Phys Med Biol, 2006 Nov 21;51(22):5843-57.
    PMID: 17068368
    We describe a semi-automated technique for the quantitative assessment of breast density from digitized mammograms in comparison with patterns suggested by Tabar. It was developed using the MATLAB-based graphical user interface applications. It is based on an interactive thresholding method, after a short automated method that shows the fibroglandular tissue area, breast area and breast density each time new thresholds are placed on the image. The breast density is taken as a percentage of the fibroglandular tissue to the breast tissue areas. It was tested in four different ways, namely by examining: (i) correlation of the quantitative assessment results with subjective classification, (ii) classification performance using the quantitative assessment technique, (iii) interobserver agreement and (iv) intraobserver agreement. The results of the quantitative assessment correlated well (r2 = 0.92) with the subjective Tabar patterns classified by the radiologist (correctly classified 83% of digitized mammograms). The average kappa coefficient for the agreement between the readers was 0.63. This indicated moderate agreement between the three observers in classifying breast density using the quantitative assessment technique. The kappa coefficient of 0.75 for intraobserver agreement reflected good agreement between two sets of readings. The technique may be useful as a supplement to the radiologist's assessment in classifying mammograms into Tabar's pattern associated with breast cancer risk.
  2. Eng HS, Mohamed Z, Calne R, Lang CC, Mohd MA, Seet WT, et al.
    Kidney Int, 2006 May;69(10):1858-64.
    PMID: 16612333
    Cyclosporine is a substrate of cytochrome P-450 3A (CYP3A) subfamily of enzymes and characterized by a narrow therapeutic range with wide interindividual variation in pharmacokinetics. A few single-nucleotide polymorphisms detected in CYP3A genes have been shown to correlate significantly with the CYP3A protein expression and activity. We therefore postulated that these polymorphisms could be responsible for some of the interindividual variation in cyclosporine pharmacokinetics. The objective of our study is to determine correlation if any between single-nucleotide polymorphisms of CYP3A5 and CYP3AP1 on cyclosporine dose requirement and concentration-to-dose ratio in renal allograft recipients. Cyclosporine-dependent renal allograft recipients were genotyped for CYP3A5 A6986G and CYP3AP1 G-44A. The cyclosporine dosages prescribed and the corresponding cyclosporine trough levels for each patient were recorded so that cyclosporine dose per weight (mg/kg/day) and concentration-to-dose ratio (C(0)/D, whereby C(0) is trough level and D is daily dose per weight) could be calculated. A total of 67 patients were recruited for our study. The dose requirement for 1, 3, and 6 months post-transplantation ranged 2.3-11.4, 1.0-9.0, and 1.4-7.2 mg/kg/day, respectively. Patients with *1*1*1*1 (n=5) CYP3A5- and CYP3AP1-linked genotypes needed higher dose of cyclosporine compared to patients with *1*3*1*3 (n = 27) and *3*3*3*3 (n = 33) linked genotypes in months 3 and 6 post-transplantation (P < 0.016). The identification of patients with *1*1*1*1 by CYP3A5 and CYP3AP1 genotyping may have a clinically significant and positive impact on patient outcome with reduced rejection rate by providing pretransplant pharmacogenetic information for optimization of cyclosporine A dosing.
  3. Chia SL, Tan WS, Shaari K, Abdul Rahman N, Yusoff K, Satyanarayanajois SD
    Peptides, 2006 Jun;27(6):1217-25.
    PMID: 16377031
    A peptide with the sequence CTLTTKLYC has previously been identified to inhibit the propagation of Newcastle disease virus (NDV) in embryonated chicken eggs and tissue culture. NDV has been classified into two main groups: the velogenic group, and mesogenic with lentogenic strains as the other group based on its dissociation constants. In this study the peptide, CTLTTKLYC, displayed on the pIII protein of a filamentous M13 phage was synthesized and mutated in order to identify the amino acid residues involved in the interactions with NDV. Mutations of C1 and K6 to A1 and A6 did not affect the binding significantly, but substitution of Y8 with A8 dramatically reduced the interaction. This suggests that Y8 plays an important role in the peptide-virus interaction. The three-dimensional structure of the peptide was determined using circular dichroism (CD), nuclear magnetic resonance (NMR), and molecular modeling. The peptide exhibited two possible conformers. One that consists of consecutive beta-turns around T2-L3-T4-T5 and K6-L7-Y8-C9. The other conformer exhibited a beta-hairpin bend type of structure with a bend around L3-T4-T5-K6.
  4. Shen H, Qi L, Tai ES, Chew SK, Tan CE, Ordovas JM
    Obesity (Silver Spring), 2006 Apr;14(4):656-61.
    PMID: 16741267
    A polymorphism in the promoter region of uncoupling protein 2 gene -866G/A has been associated with its expression levels in adipose tissue, the risk of obesity, and metabolic abnormalities. Our purpose was to examine the associations of -866G/A with body fat and the risk of metabolic syndrome in a random sample of 4018 Asians (1858 men and 2160 women) from three ethnic groups (Chinese, Malay, and Indian). The minor allele frequency of -866G/A polymorphism in South Asians was similar to that in whites. After adjustment for covariates including age, cigarette smoking, and physical activity, the -866A/A genotype was associated with higher waist-to-hip ratio as compared with the wild-type genotype in Chinese and Indian men (p = 0.018 and p = 0.046, respectively). Moreover, Indian men with -866A/A genotype had a significantly increased risk of metabolic syndrome as compared with those homozygous for the wild-type (odds ratio, 2.66; 95% confidence interval, 1.21 to 5.88; p = 0.015). Such a risk was mainly caused by the excess presence of hypertriglyceridemia and central obesity. Our findings indicate that the uncoupling protein 2 gene -866G/A polymorphism may increase the risks of central obesity and metabolic syndrome, with greater effects on Asian men.
  5. Loh LC, Chan LY, Tan RY, Govindaraju S, Ratnavelu K, Kumar S, et al.
    Asia Pac J Public Health, 2006;18(1):69-71.
    PMID: 16629441
    The prognosis of lung cancer remains poor with overall five year survival figures varying between five and 10% worldwide, However, it has been shown that surgery in patients with early stage disease in non-small cell lung cancer can achieve five year survival rates up to 80%, suggesting that early or delay diagnosis can influence prognosis. Nevertheless, studies addressing this have been inconclusive and mostly derived from Western countries.
  6. Loh LC, Chan SK, Ch'ng KI, Tan LZ, Vijayasingham P, Thayaparan T
    Med J Malaysia, 2005 Oct;60(4):426-31.
    PMID: 16570703
    In the Malaysian setting of multi-ethnicity and high BCG coverage, interpretation of Tuberculin Skin Testing (TST) may be difficult. Between January 2001 and December 2003, a retrospective study on all adult patients with documented TST results treated for tuberculosis (TB) in chest clinics of two government hospitals was conducted to determine the reliability of TST and factors affecting its interpretation. One hundred and three patients [mean age (SD): 43 (17); male: 67%] were eligible for data collection: 72% and 57% of patients had positive TST results based on cut-off points of 10mm and 15mm respectively. The only significant univariate association with TST results was the severity of co-morbidity. A patient with co-morbidity score of 3 defined as those with any cancer, end-stage renal or liver disease, or HIV disease, was more likely to have a negative TST results [10mm cut-off point: Odd Ratio (95% CI) 6.6 (1.82 to 24.35), p = 0.003; 15mm cut-off point: 4.8 (1.21 to 18.95), p = 0.012]. A TST reading of 10mm had a higher sensitivity than 15mm as the cut-off point in diagnosing TB infection. Considering all possible confounding factors like ethnicity, prior BCG vaccination and TB burden in the population, severity of co-morbidity remains strongly predictive of a negative TST. Caution should be exercised in interpreting TST in these patients.
    Study site: Chest clinic, Hospital Seremban, Hospital Kuala Pilah, Negeri Sembilan, Malaysia
  7. Tan SMK, Azmi MT, Reddy JP, Shaharom MH, Rosdinom R, Maniam T, et al.
    Med J Malaysia, 2005 Aug;60(3):328-37.
    PMID: 16379188
    Stigmatising attitudes towards mental illness may improve with clinical exposure during medical school training. Attitudes of 48 fourth year medical students in Universiti Kebangsaan Malaysia were assessed before and after their compulsory attachment in Psychiatry, using the Attitude Towards Psychiatry-30 (ATP) and the Attitude towards Mental Illness (AMI) questionnaires. ATP scores improved significantly with training (104.8 and 114.4, pre- and post-attachment respectively) as did AMI scores (63.4 and 68.1 respectively). Both improvements were statistically significant. (ATP: z = 4.55, p < 0.0005) (AMI: z = 3.75, p < 0.0005). Attitudes towards mental illness appeared to have become more favourable with clinical training in psychiatry.
  8. Tan HL, Nah SA, Budianto II, Sehat S, Tamba R
    J Pediatr Surg, 2012 Dec;47(12):2294-7.
    PMID: 23217892 DOI: 10.1016/j.jpedsurg.2012.09.022
    Octyl cyanoacrylate has been used for many years for simple skin closure, but its use in hypospadias repair and as a urethral stent fixator has not been previously reported. We report our experience.
  9. Tan HY, Sieo CC, Abdullah N, Liang JB, Huang XD, Ho YW
    J. Eukaryot. Microbiol., 2013 Jan-Feb;60(1):98-100.
    PMID: 23205499 DOI: 10.1111/jeu.12011
    Molecular diversity of protists from bovine rumen fluid incubated with condensed tannins of Leucaena leucocephala hybrid-Rendang at 20 mg/500 mg dry matter (treatment) or without condensed tannins (control) was investigated using 18S rRNA gene library. Clones from the control library were distributed within nine genera, but clones from the condensed tannin treatment clone library were related to only six genera. Diversity estimators such as abundance-based coverage estimation and Chao1 showed significant differences between the two libraries, although no differences were found based on Shannon-Weaver index and Libshuff.
  10. Chan LF, Tan SM, Ang JK, Kamal Nor N, Sharip S
    J Child Sex Abus, 2012;21(6):613-20.
    PMID: 23194137 DOI: 10.1080/10538712.2012.719597
    Adolescent sexual abuse is not an uncommon phenomenon in Malaysia. It is a traumatic experience that complicates the psychosocial development of young people on the threshold of adulthood. This case report highlights the psychosocial sequelae of adolescent sexual abuse by a traditional healer and discusses management issues in the context of unique cultural and belief systems.
  11. Tan TH, Lee BN, Amir Hassan SZ, Ch'ng ES, Hussein Z
    Nucl Med Mol Imaging, 2012 Dec;46(4):300-3.
    PMID: 24900078 DOI: 10.1007/s13139-012-0160-x
    Ectopic thyroid or thyroid ectopia is a rare developmental anomaly with the prevalence of 1 per 100,000-300,000 population. Even rarer, such an anomaly manifests as dual thyroid ectopia. To our best knowledge, only one case has been reported on dual thyroid ectopia with Graves' disease in the English literature. We present here a case of dual thyroid ectopia complicated by Graves' disease, whereby the diagnosis was rendered through judicious use of various diagnostic modalities coupled with a close clinical follow-up. In this case, therapeutic consideration should be personalized with proper informed consent of the patient.
  12. Alitheen NB, McClure SJ, Yeap SK, Kristeen-Teo YW, Tan SW, McCullagh P
    PLoS One, 2012;7(11):e49188.
    PMID: 23185307 DOI: 10.1371/journal.pone.0049188
    The bursa of Fabricius is critical for B cell development and differentiation in chick embryos. This study describes the production in vitro, from dissociated cell suspensions, of cellular agglomerates with functional similarities to the chicken bursa. Co-cultivation of epithelial and lymphoid cells obtained from embryos at the appropriate developmental stage regularly led to agglomerate formation within 48 hours. These agglomerates resembled bursal tissue in having lymphoid clusters overlaid by well organized epithelium. Whereas lymphocytes within agglomerates were predominantly Bu-1a(+), a majority of those emigrating onto the supporting membrane were Bu-1a(-) and IgM(+). Both agglomerates and emigrant cells expressed activation-induced deaminase with levels increasing after 24 hours. Emigrating cells were actively proliferating at a rate in excess of both the starting cell population and the population of cells remaining in agglomerates. The potential usefulness of this system for investigating the response of bursal tissue to avian Newcastle disease virus (strain AF2240) was examined.
  13. Yoon KY, Tan WS, Tey BT, Lee KW, Ho KL
    Electrophoresis, 2013 Jan;34(2):244-53.
    PMID: 23161478 DOI: 10.1002/elps.201200257
    Hepatitis B core antigen (HBcAg) expressed in Escherichia coli is able to self-assemble into large and small capsids comprising 240 (triangulation number T = 4) and 180 (triangulation number T = 3) subunits, respectively. Conventionally, sucrose density gradient ultracentrifugation and SEC have been used to separate these capsids. However, good separation of the large and small particles with these methods is never achieved. In the present study, we employed a simple, fast, and cost-effective method to separate the T = 3 and T = 4 HBcAg capsids by using native agarose gel electrophoresis followed by an electroelution method (NAGE-EE). This is a direct, fast, and economic method for isolating the large and small HBcAg particles homogenously based on the hydrodynamic radius of the spherical particles. Dynamic light scattering analysis demonstrated that the T = 3 and T = 4 HBcAg capsids prepared using the NAGE-EE method are monodisperse with polydispersity values of ∼15% and ∼13%, respectively. ELISA proved that the antigenicity of the capsids was not affected in the purification process. Overall, NAGE-EE produced T = 3 and T = 4 capsids with a purity above 90%, and the recovery was 34% and 50%, respectively (total recovery of HBcAg is ∼84%), and the operation time is 15 and 4 times lesser than that of the sucrose density gradient ultracentrifugation and SEC, respectively.
  14. Hooi LS, Lim TO, Goh A, Wong HS, Tan CC, Ahmad G, et al.
    Nephrology (Carlton), 2005 Feb;10(1):25-32.
    PMID: 15705178 DOI: 10.1111/j.1440-1797.2005.00360.x
    BACKGROUND: This is a multi-centre study to determine cost efficiency and cost effectiveness of the Ministry of Health centre haemodialysis and continuous ambulatory peritoneal dialysis (CAPD) programme.
    METHODS: Forty-four haemodialysis and 11 CAPD centres were enrolled in this study in 2001. Sixty patients, 30 from each modality, were evaluated. Micro-costing was used to determine costs.
    RESULTS: The number of haemodialyses conducted ranged from 402 to 23,000 procedures per year, while for CAPD, output ranged from 70 to 2300 patient months/year. Cost ranged from RM79.61 to RM475.79 per haemodialysis treatment, with a mean cost of RM169 per HD (USD 1 = RM 3.80). The cost of CAPD treatment ranged from RM1400 to RM3200 per patient month, with a mean of RM2186. Both modalities incurred similar outpatient costs. The cost of erythropoeitin per year is RM4500 and RM2500 for haemodialysis and CAPD, respectively. The number of life years saved is 10.96 years for haemodialysis and 5.21 years for CAPD. Cost per life year saved is RM33 642 for haemodialysis and RM31 635 for CAPD. The cost for land, building, equipment, overheads, and staff were higher for haemodialysis, while consumables and hospitalization cost more for CAPD. Sensitivity analysis was performed for two discount rates (3 and 5%), varying erythropoietin doses and maximum and minimum overheads. Relative cost effectiveness of haemodialysis and CAPD was unchanged in all sensitivity scenarios, except for overhead costs, which influenced the cost effectiveness of HD.
    CONCLUSION: It is economically viable to promote the use of both CAPD and haemodialysis because the cost effectiveness of both are nearly equal.
  15. Venketasubramanian N, Tan LC, Sahadevan S, Chin JJ, Krishnamoorthy ES, Hong CY, et al.
    Stroke, 2005 Mar;36(3):551-6.
    PMID: 15692124
    Stroke prevalence data among mixed Asian populations are lacking. Prevalence rates of stroke were studied among Singaporeans aged > or =50 years of Chinese, Malay, and Indian origin.
  16. Ang HC, Sornarajah R, Lim SE, Syn CK, Tan-Siew WF, Chow ST, et al.
    Forensic Sci Int, 2005 Mar 10;148(2-3):243-5.
    PMID: 15639622
    Allele frequencies for the 13 CODIS (Combined DNA Index System, USA) STR loci included in the AmpFISTR Profiler Plus and AmpFISTR Cofiler kits (Applied Biosystems, Foster City, USA) were determined in a sample of 197 unrelated Malays in Singapore.
  17. Tan ML, Sulaiman SF, Najimuddin N, Samian MR, Muhammad TS
    J Ethnopharmacol, 2005 Jan 4;96(1-2):287-94.
    PMID: 15588681
    Currently, breast cancer is the leading cause of cancer-related death in women. Therefore, there is an urgent need to develop alternative therapeutic measures against this deadly disease. Here, we report the cytotoxicity activity and the mechanism of cell death exhibited by the methanol extract prepared from Pereskia bleo (Kunth) DC. (Cactaceae) plant against human breast carcinoma cell line, T-47D. In vitro cytotoxicity screening of methanol extract of Pereskia bleo plant indicated the presence of cytotoxicity activity of the extract against T-47D cells with EC50 of 2.0 microg/ml. T-47D cell death elicited by the extract was found to be apoptotic in nature based a clear indication of DNA fragmentation which is a hallmark of apoptosis. In addition, ultrastructural analysis also revealed apoptotic characteristics (the presence of chromatin margination and apoptotic bodies) in the extract-treated cells. RT-PCR analysis showed the mRNA expression levels of c-myc, and caspase 3 were markedly increased in the cells treated with the plant extract. However, p53 expression was only slightly increased as compared to caspase 3 and c-myc. Thus, the results from this study strongly suggest that the methanol extract of Pereskia bleo may contain bioactive compound(s) that caused breast carcinoma, T-47D cell death by apoptosis mechanism via the activation of caspase-3 and c-myc pathways.
  18. Gan WH, Thye YL, Chang SH, Chua CB, Looi LM, Tan SY
    Transplant Proc, 2004 Sep;36(7):2148-9.
    PMID: 15518779
  19. Phang MY, Ng MH, Tan KK, Aminuddin BS, Ruszymah BH, Fauziah O
    Med J Malaysia, 2004 May;59 Suppl B:198-9.
    PMID: 15468886
    Tricalcium phosphate/hydroxyapatite (TCP/HA), hydroxyapatite (HA), chitosan and calcium sulphate (CaSO4) were studied and evaluated for possible bone tissue engineered construct acting as good support for osteogenic cells to proliferate, differentiate, and eventually spread and integrate into the scaffold. Surface morphology visualized by SEM showed that scaffold materials with additional fibrin had more cell densities attached than those without, depicting that the presence of fibrin and collagen fibers were truly a favourite choice of cells to attach. In comparison of various biomaterials used incorporated with fibrin, TCP/HA had the most cluster of cells attached.
  20. Ling TC, Loong CK, Tan WS, Tey BT, Abdullah WM, Ariff A
    J Microbiol, 2004 Sep;42(3):228-32.
    PMID: 15459653
    In this paper, we investigated the development of a simplified and rapid primary capture step for the recovery of M13 bacteriophage from particulate-containing feedstock. M13 bacteriophage, carrying an insert, was propagated and subsequently purified by the application of both conventional multiple steps and expanded bed anion exchange chromatography. In the conventional method, precipitation was conducted with PEG/NaCl, and centrifugation was also performed. In the single step expanded bed anion exchange adsorption, UpFront FastLine 20 (20 mm i.d.) from UpFront Chromatography was used as the contactor, while 54 ml (Ho = 15 cm) of STREAMLINE DEAE (rho = 1.2 g/cm3) from Amersham Pharmacia Biotechnology was used as the anion exchanger. The performance of the two methods were evaluated, analysed, and compared. It was demonstrated that the purification of the M13 bacteriophage, using expanded bed anion exchange adsorption, yielded the higher recovery percentage, at 82.86%. The conventional multiple step method yielded the lower recovery percentage, 36.07%. The generic application of this integrated technique has also been assessed.
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