Displaying publications 2421 - 2440 of 3446 in total

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  1. Ariffin H, Hainaut P, Puzio-Kuter A, Choong SS, Chan AS, Tolkunov D, et al.
    Proc Natl Acad Sci U S A, 2014 Oct 28;111(43):15497-501.
    PMID: 25313051 DOI: 10.1073/pnas.1417322111
    The Li-Fraumeni syndrome (LFS) and its variant form (LFL) is a familial predisposition to multiple forms of childhood, adolescent, and adult cancers associated with germ-line mutation in the TP53 tumor suppressor gene. Individual disparities in tumor patterns are compounded by acceleration of cancer onset with successive generations. It has been suggested that this apparent anticipation pattern may result from germ-line genomic instability in TP53 mutation carriers, causing increased DNA copy-number variations (CNVs) with successive generations. To address the genetic basis of phenotypic disparities of LFS/LFL, we performed whole-genome sequencing (WGS) of 13 subjects from two generations of an LFS kindred. Neither de novo CNV nor significant difference in total CNV was detected in relation with successive generations or with age at cancer onset. These observations were consistent with an experimental mouse model system showing that trp53 deficiency in the germ line of father or mother did not increase CNV occurrence in the offspring. On the other hand, individual records on 1,771 TP53 mutation carriers from 294 pedigrees were compiled to assess genetic anticipation patterns (International Agency for Research on Cancer TP53 database). No strictly defined anticipation pattern was observed. Rather, in multigeneration families, cancer onset was delayed in older compared with recent generations. These observations support an alternative model for apparent anticipation in which rare variants from noncarrier parents may attenuate constitutive resistance to tumorigenesis in the offspring of TP53 mutation carriers with late cancer onset.
    Matched MeSH terms: Sequence Analysis, DNA; DNA Copy Number Variations/genetics
  2. Teh CS, Suhaili Z, Lim KT, Khamaruddin MA, Yahya F, Sajili MH, et al.
    Emerg Infect Dis, 2012 Jul;18(7):1177-9.
    PMID: 22709679 DOI: 10.3201/eid1807.111656
    A cholera outbreak in Terengganu, Malaysia, in November 2009 was caused by 2 El Tor Vibrio cholerae variants resistant to typical antimicrobial drugs. Evidence of replacement of treatable V. cholerae infection in the region with antimicrobial-resistant strains calls for increased surveillance and prevention measures.
    Matched MeSH terms: DNA, Bacterial/genetics; Sequence Analysis, DNA
  3. Cheng YC, Stanne TM, Giese AK, Ho WK, Traylor M, Amouyel P, et al.
    Stroke, 2016 Feb;47(2):307-16.
    PMID: 26732560 DOI: 10.1161/STROKEAHA.115.011328
    BACKGROUND AND PURPOSE: Although a genetic contribution to ischemic stroke is well recognized, only a handful of stroke loci have been identified by large-scale genetic association studies to date. Hypothesizing that genetic effects might be stronger for early- versus late-onset stroke, we conducted a 2-stage meta-analysis of genome-wide association studies, focusing on stroke cases with an age of onset <60 years.

    METHODS: The discovery stage of our genome-wide association studies included 4505 cases and 21 968 controls of European, South-Asian, and African ancestry, drawn from 6 studies. In Stage 2, we selected the lead genetic variants at loci with association P<5×10(-6) and performed in silico association analyses in an independent sample of ≤1003 cases and 7745 controls.

    RESULTS: One stroke susceptibility locus at 10q25 reached genome-wide significance in the combined analysis of all samples from the discovery and follow-up stages (rs11196288; odds ratio =1.41; P=9.5×10(-9)). The associated locus is in an intergenic region between TCF7L2 and HABP2. In a further analysis in an independent sample, we found that 2 single nucleotide polymorphisms in high linkage disequilibrium with rs11196288 were significantly associated with total plasma factor VII-activating protease levels, a product of HABP2.

    CONCLUSIONS: HABP2, which encodes an extracellular serine protease involved in coagulation, fibrinolysis, and inflammatory pathways, may be a genetic susceptibility locus for early-onset stroke.

    Matched MeSH terms: DNA, Intergenic/genetics
  4. Alkotaini B, Anuar N, Kadhum AA
    Appl Biochem Biotechnol, 2015 Feb;175(4):1868-78.
    PMID: 25427593 DOI: 10.1007/s12010-014-1410-4
    The mechanisms of action of AN5-1 against Gram-negative and Gram-positive bacteria were investigated by evaluations of the intracellular content leakage and by microscopic observations of the treated cells. Escherichia coli and Staphylococcus aureus were used for this investigation. Measurements of DNA, RNA, proteins, and β-galactosidase were taken, and the results showed a significant increase in the cultivation media after treatment with AN5-1 compared with the untreated cells. The morphological changes of treated cells were shown using transmission electron microscopy (TEM) and atomic force microscopy (AFM). The observations showed that AN5-1 acts against E. coli and against S. aureus in similar ways, by targeting the cell wall, causing disruptions; at a high concentration (80 AU/ml), these disruptions led to cell lysis. The 3D AFM imaging system showed that at a low concentration of 20 AU/ml, the effect of AN5-1 is restricted to pore formation only. Moreover, a separation between the cell wall and the cytoplasm was observed when Gram-negative bacteria were treated with a low concentration (20 AU/ml) of AN5-1.
    Matched MeSH terms: DNA, Bacterial/metabolism
  5. Wei LK, Sutherland H, Au A, Camilleri E, Haupt LM, Gan SH, et al.
    Biomed Res Int, 2015;2015:167976.
    PMID: 25705649 DOI: 10.1155/2015/167976
    Stroke is a multifactorial disease that may be associated with aberrant DNA methylation profiles. We investigated epigenetic dysregulation for the methylenetetrahydrofolate reductase (MTHFR) gene among ischemic stroke patients. Cases and controls were recruited after obtaining signed written informed consents following a screening process against the inclusion/exclusion criteria. Serum vitamin profiles (folate, vitamin B12, and homocysteine) were determined using immunoassays. Methylation profiles for CpGs A and B in the MTHFR gene were determined using a bisulfite-pyrosequencing method. Methylation of MTHFR significantly increased the susceptibility risk for ischemic stroke. In particular, CpG A outperformed CpG B in mediating serum folate and vitamin B12 levels to increase ischemic stroke susceptibility risks by 4.73-fold. However, both CpGs A and B were not associated with serum homocysteine levels or ischemic stroke severity. CpG A is a potential epigenetic marker in mediating serum folate and vitamin B12 to contribute to ischemic stroke.
    Matched MeSH terms: DNA Methylation/genetics
  6. Wan Abdul Rahman WF, Fauzi MH, Jaafar H
    Asian Pac J Cancer Prev, 2014;15(19):8441-5.
    PMID: 25339043
    BACKGROUND: Paired-like homeodomain transcription factor 2 (PITX2) is another new marker in breast carcinoma since hypermethylation at P2 promoter of this gene was noted to be associated with poor prognosis. We investigated the expression of PITX2 protein using immunohistochemistry in invasive ductal carcinoma and its association with the established growth receptors such as estrogen receptor (ER), progesterone receptor (PR) and human epidermal growth receptor 2 (HER2).

    METHODS: We conducted a cross sectional study using 100 samples of archived formalin-fixed paraffin embedded tissue blocks of invasive ductal carcinoma and stained them with immunohistochemistry for PITX2, ER, PR and HER2. All HER2 with scoring of 2+ were confirmed with chromogenic in-situ hybridization (CISH).

    RESULTS: PITX2 protein was expressed in 53% of invasive ductal carcinoma and lack of PITX2 expression in 47%. Univariate analysis revealed a significant association between PITX2 expression with PR (p=0.001), ER (p=0.006), gland formation (p=0.044) and marginal association with molecular subtypes of breast carcinoma (p=0.051). Combined ER and PR expression with PITX2 was also significantly associated (p=0.003) especially in double positive cases. Multivariate analysis showed the most significant association between PITX2 and PR (RR 4.105, 95% CI 1.765-9.547, p=0.001).

    CONCLUSION: PITX2 is another potential prognostic marker in breast carcinoma adding significant information to established prognostic factors of ER and PR. The expression of PITX2 together with PR may carry a very good prognosis.

    Matched MeSH terms: DNA Methylation*
  7. Omar A, Bakar OC, Adam NF, Osman H, Osman A, Suleiman AH, et al.
    Korean J Parasitol, 2015 Feb;53(1):29-34.
    PMID: 25748706 DOI: 10.3347/kjp.2015.53.1.29
    The aim of this cross sectional case control study was to examine the serofrequency and serointensity of Toxoplasma gondii (Tg) IgG, IgM, and DNA among patients with schizophrenia. A total of 101 patients with schizophrenia and 55 healthy controls from Sungai Buloh Hospital, Selangor, Malaysia and University Malaya Medical Center (UMMC) were included in this study. The diagnosis of schizophrenia was made based on the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV). The presence of Tg infection was examined using both indirect (ELISA) and direct (quantitative real-time PCR) detection methods by measuring Tg IgG and IgM and DNA, respectively. The serofrequency of Tg IgG antibodies (51.5%, 52/101) and DNA (32.67%, 33/101) among patients with schizophrenia was significantly higher than IgG (18.2%, 10/55) and DNA (3.64%, 2/55) of the controls (IgG, P=0.000, OD=4.8, CI=2.2-10.5; DNA, P=0.000, OD=12.9, CI=2.17-10.51). However, the Tg IgM antibody between patients with schizophrenia and controls was not significant (P>0.005). There was no significant difference (P>0.005) in both serointensity of Tg IgG and DNA between patients with schizophrenia and controls. These findings have further demonstrated the strong association between the active Tg infection and schizophrenia.
    Matched MeSH terms: DNA, Protozoan/blood*
  8. Lee CC, Harun F, Jalaludin MY, Heh CH, Othman R, Junit SM
    BMJ Open, 2015 Jan 05;5(1):e006121.
    PMID: 25564141 DOI: 10.1136/bmjopen-2014-006121
    OBJECTIVES: The c.2268dup mutation in the thyroid peroxidase (TPO) gene is the most common TPO alteration reported in Taiwanese patients with thyroid dyshormonogenesis. The ancestors of these patients are believed to originate from the southern province of China. Our previous study showed that this mutation leads to reduced abundance of the TPO protein and loss of TPO enzyme activity in a Malaysian-Chinese family with goitrous hypothyroidism. The aim of our study was to provide further data on the incidence of the c.2268dup mutation in a cohort of Malaysian-Chinese and its possible phenotypic effects.

    SETTING: Cohort study.

    PARTICIPANTS: Twelve biologically unrelated Malaysian-Chinese patients with congenital hypothyroidism were recruited in this study. All patients showed high thyrotropin and low free thyroxine levels at the time of diagnosis with proven presence of a thyroid gland.

    PRIMARY OUTCOME MEASURE: Screening of the c.2268dup mutation in the TPO gene in all patients was carried out using a PCR-direct DNA sequencing method.

    SECONDARY OUTCOME MEASURE: Further screening for mutations in other exonic regions of the TPO gene was carried out if the patient was a carrier of the c.2268dup mutation.

    RESULTS: The c.2268dup mutation was detected in 4 of the 12 patients. Apart from the c.2268dup and a previously documented mutation (c.2647C>T), two novel TPO alterations, c.670_672del and c.1186C>T, were also detected in our patients. In silico analyses predicted that the novel alterations affect the structure/function of the TPO protein.

    CONCLUSIONS: The c.2268dup mutation was detected in approximately one-third of the Malaysian-Chinese patients with thyroid dyshormonogenesis. The detection of the novel c.670_672del and c.1186C>T alterations expand the mutation spectrum of TPO associated with thyroid dyshormonogenesis.

    Matched MeSH terms: Sequence Analysis, DNA/methods
  9. Ng CH, Akhter A, Yurko N, Burgener JM, Rosonina E, Manley JL
    Nat Commun, 2015 Mar 13;6:6610.
    PMID: 25766875 DOI: 10.1038/ncomms7610
    The small ubiquitin-like modifier (SUMO) is implicated in various cellular activities, including transcriptional regulation. We previously showed that the yeast activator Gcn4 becomes sumoylated during activation, facilitating its eventual promoter eviction and transcriptional shut off. Here we show that the corepressor Tup1 is sumoylated, at two specific lysines, under various stress conditions. Mutation of these sites has no effect on Tup1 recruitment or RNAP II promoter occupancy immediately following induction. However, Tup1 levels subsequently decrease, while RNAP II and transcription increase in Tup1 mutant cells. Consistent with this, a Tup1 mutant displaying increased sumoylation led to reduced transcription. We also show that coordinated sumoylation of Gcn4 and Tup1 enhances Gcn4 promoter eviction and that multiple Tup1-interacting proteins become sumoylated after stress. Together, our studies provide evidence that coordinated sumoylation of Gcn4, Tup1 and likely other factors dampens activated transcription by stabilizing Tup1 binding and stimulating Gcn4 and RNAP II removal.
    Matched MeSH terms: DNA-Binding Proteins/metabolism
  10. Chen Q, Narayanan K
    Methods Mol Biol, 2015;1227:27-54.
    PMID: 25239740 DOI: 10.1007/978-1-4939-1652-8_2
    Recombineering is a powerful genetic engineering technique based on homologous recombination that can be used to accurately modify DNA independent of its sequence or size. One novel application of recombineering is the assembly of linear BACs in E. coli that can replicate autonomously as linear plasmids. A circular BAC is inserted with a short telomeric sequence from phage N15, which is subsequently cut and rejoined by the phage protelomerase enzyme to generate a linear BAC with terminal hairpin telomeres. Telomere-capped linear BACs are protected against exonuclease attack both in vitro and in vivo in E. coli cells and can replicate stably. Here we describe step-by-step protocols to linearize any BAC clone by recombineering, including inserting and screening for presence of the N15 telomeric sequence, linearizing BACs in vivo in E. coli, extracting linear BACs, and verifying the presence of hairpin telomere structures. Linear BACs may be useful for functional expression of genomic loci in cells, maintenance of linear viral genomes in their natural conformation, and for constructing innovative artificial chromosome structures for applications in mammalian and plant cells.
    Matched MeSH terms: DNA Replication*
  11. Chong PP, Tung CH, Rahman NA, Yajima M, Chin FW, Yeng CL, et al.
    Acta Ophthalmol, 2014 Nov;92(7):e569-79.
    PMID: 25043991 DOI: 10.1111/aos.12427
    The aim of the study was to determine the prevalence of human papillomavirus (HPV) in primary and recurrent pterygia samples collected from different ethnic groups in the equatorial Malay Peninsula.
    Matched MeSH terms: DNA, Viral/analysis
  12. Yong ZW, Zaini ZM, Kallarakkal TG, Karen-Ng LP, Rahman ZA, Ismail SM, et al.
    Sci Rep, 2014;4:6073.
    PMID: 25123227 DOI: 10.1038/srep06073
    The clinical relevance of DNA copy number alterations in chromosome 8 were investigated in oral cancers. The copy numbers of 30 selected genes in 33 OSCC patients were detected using the multiplex ligation-dependent probe amplification (MLPA) technique. Amplifications of the EIF3E gene were found in 27.3% of the patients, MYC in 18.2%, RECQL4 in 15.2% and MYBL1 in 12.1% of patients. The most frequent gene losses found were the GATA4 gene (24.2%), FGFR1 gene (24.2%), MSRA (21.2) and CSGALNACT1 (12.1%). The co-amplification of EIF3E and RECQL4 was found in 9% of patients and showed significant association with alcohol drinkers. There was a significant association between the amplification of EIF3E gene with non-betel quid chewers and the negative lymph node status. EIF3E amplifications did not show prognostic significance on survival. Our results suggest that EIF3E may have a role in the carcinogenesis of OSCC in non-betel quid chewers.
    Matched MeSH terms: DNA Copy Number Variations/genetics*
  13. Petz LN, Turell MJ, Padilla S, Long LS, Reinbold-Wasson DD, Smith DR, et al.
    Am J Trop Med Hyg, 2014 Oct;91(4):666-71.
    PMID: 25114013 DOI: 10.4269/ajtmh.13-0218
    Tembusu virus (TMUV) is an important emerging arthropod-borne virus that may cause encephalitis in humans and has been isolated in regions of southeast Asia, including Malaysia, Thailand, and China. Currently, detection and identification of TMUV are limited to research laboratories, because quantitative rapid diagnostic assays for the virus do not exist. We describe the development of sensitive and specific conventional and real-time quantitative reverse transcription polymerase chain reaction assays for detecting TMUV RNA in infected cell culture supernatant and Culex tarsalis mosquitoes. We used this assay to document the replication of TMUV in Cx. tarsalis, where titers increased 1,000-fold 5 days after inoculation. These assays resulted in the detection of virus-specific RNA in the presence of copurified mosquito nucleic acids. The use of these rapid diagnostic assays may have future applications for field pathogen surveillance and may assist in early detection, diagnosis, and control of the associated arthropod-borne pathogens.
    Matched MeSH terms: DNA Primers/genetics
  14. Cheng J, Wang Y, Hou J, Luo D, Xie Q, Ning Q, et al.
    J Clin Virol, 2014 Dec;61(4):509-16.
    PMID: 25200354 DOI: 10.1016/j.jcv.2014.08.008
    In mainland China, peginterferon (PEG-IFN) alfa-2b 1.0μg/kg/wk for 24 weeks is the approved treatment for HBeAg-positive chronic hepatitis B.
    Matched MeSH terms: DNA, Viral/blood
  15. Ahmad A, Dada AC, Usup G, Heng LY
    Mar Pollut Bull, 2014 May 15;82(1-2):26-38.
    PMID: 24725825 DOI: 10.1016/j.marpolbul.2014.03.028
    Median enterococci counts of beach water samples gradually increased at statistically significant levels (χ2: 26.53, df: 4; p<0.0001) with increasing proximity to river influx. The difference in proportion of antibiotic resistant enterococci in beach water and river water samples was statistically significant (p<0.05) for the tested antibiotics with river isolates generally presenting higher resistance frequencies. Virulence genes cyl, esp, gelE and asa were detected at varying frequencies (7.32%, 21.95%, 100% and 63.41% respectively) among river isolates. On the other hand, the prevalence of these genes was lower (0%, 20%, 67.27% and 41.82% respectively) among beach water isolates. Multi-Locus-Sequence-Typing analysis of Enterococcus faecalis presented four sequence types (ST) one of which shared six out of seven tested loci with ST6, a member of the clonal complex of multi-drug resistant strains associated with hospital outbreaks.
    Matched MeSH terms: DNA, Bacterial/genetics
  16. Safi SZ, Qvist R, Yan GO, Ismail IS
    BMC Med Genomics, 2014;7:29.
    PMID: 24885710 DOI: 10.1186/1755-8794-7-29
    Aberrant epigenetic profiles are concomitant with a spectrum of developmental defects and diseases. Role of methylation is an increasingly accepted factor in the pathophysiology of diabetes and its associated complications. This study aims to examine the correlation between oxidative stress and methylation of β1, β2 and β3-adrenergic receptors and to analyze the differential variability in the expression of these genes under hyperglycemic conditions.
    Matched MeSH terms: DNA Methylation/genetics
  17. Othman N, Othman NH
    Asian Pac J Cancer Prev, 2014;15(5):2245-9.
    PMID: 24716964
    BACKGROUND: Human papillomavirus is a well-established cause of the development of a variety of epithelial lesions in the cervix. However, as yet, incorporation of HPV testing into cervical cancer screening either as an adjunct or stand alone test is limited due to its cost. We therefore here ascertained the presence and type specificity of human papilloma virus (HPV) DNA in routine cervical scrapings.

    MATERIALS AND METHODS: Cervical scrapings were collected from women attending clinics for routine Pap smear screening. HPV-DNA was detected by PCR using MY09/11 and GP5+/GP6+ primer sets and genotyping was accomplished by cycle-sequencing.

    RESULTS: A total of 635 women were recruited into the study with mean ± SD age of 43 ± 10.5 years. Of these 92.6% (588/635) were reported as within normal limits (WNL) on cytology. The presence of HPV infection detected by nested MY/GP+-PCR was 4.4% (28/635). The overall prevalence of high-risk HPV (HR-HPV) in abnormal Pap smears was 53.8% (7/13). HPVs were also seen in 3.1% (18/588) of smears reported as WNL by cytology and 5.9% (2/34) in smears unsatisfactory for evaluation.

    CONCLUSIONS: The overall percentage of HPV positivity in routine cervical screening samples is comparable with abnormal findings in cytology. Conventional Pap smear 'missed' a few samples. Since HPV testing is expensive, our results may provide valuable information for strategising implementation of effective cervical cancer screening in a country with limited resources like Malaysia. If Pap smear coverage could be improved, HPV testing could be used as an adjunct method on cases with ambiguous diagnoses.

    Matched MeSH terms: DNA, Viral/genetics*
  18. Nur-Nazifah M, Sabri MY, Siti-Zahrah A
    Fish Shellfish Immunol, 2014 Mar;37(1):193-200.
    PMID: 24486904 DOI: 10.1016/j.fsi.2014.01.011
    This study was carried out to determine the antibody responses and protective capacity of an inactivated recombinant vaccine expressing the cell wall surface anchor family protein of Streptococcus agalactiae following oral vaccination against streptococcosis in tilapia. Tilapia were vaccinated orally with 10(6) CFU/mL of the recombinant vaccine incorporated in feed (feed-based recombinant vaccine) (vaccinated group or Group 1), 10(6) CFU/mL of pET-32 Ek/LIC vector without cell wall surface anchor family protein (control group or Group 2), 10(6) CFU/mL of formalin-killed cells of S. agalactiae vaccine incorporated in feed was also prepared (feed-based vaccine) (vaccinated group or Group 3), and unvaccinated control group or Group 4 (fed with commercial pellets). During the course of study, serum, mucus and gut lavage fluid were collected to evaluate the antibody levels via enzyme-linked immunosorbent assay (ELISA). The results showed that tilapia immunized with the feed-based recombinant vaccine developed a strong and significantly (P 
    Matched MeSH terms: DNA Primers/genetics
  19. Loy SL, Jan Mohamed HJ
    Women Health, 2014;54(2):145-60.
    PMID: 24329183 DOI: 10.1080/03630242.2013.870632
    This study aimed to examine the associations among prenatal nicotine exposure, oxidative stress, and postpartum visceral fat among women exposed to secondhand smoke (SHS). The study was conducted in Kelantan, Malaysia, from April 2010 to December 2012. Blood samples were collected in the second and third trimesters from 135 healthy pregnant women who were followed-up at delivery, 2 months, 6 months and 12 months postpartum. Maternal hair nicotine and oxidative stress markers during pregnancy were measured. Visceral fat was assessed by bioelectrical impedance. Multiple linear regression analysis revealed that maternal hair nicotine concentration was associated with increased DNA damage (tail moment: β=0.580, p=0.001) and decreased glutathione peroxidase (β=-12.100; p=0.009) in the second trimester of pregnancy. Increased DNA damage, protein oxidation and total antioxidant capacity in the second trimester were associated with 2, 6, and 12 months postpartum visceral fat. No direct association was found between prenatal hair nicotine level and postpartum visceral fat; however, these results suggest that any relation of SHS to visceral adiposity may be indirect, mediated via enhanced oxidative stress.
    Matched MeSH terms: DNA Damage/physiology
  20. Lee SK, Tan KW, Ng SW, Ooi KK, Ang KP, Abdah MA
    PMID: 24231745 DOI: 10.1016/j.saa.2013.10.084
    A cationic Schiff base ligand, TSB (L) and its Zn (II) complex (1) were synthesized and characterized by using CHN, (1)H-NMR, FT-IR, UV, LC-MS, and X-ray methods. Their ability to inhibit topoisomerase I, DNA cleavage activities, and cytotoxicity were studied. X-ray diffraction study shows that the mononuclear complex 1 is four coordinated with distorted tetrahedral geometry. The singly deprotonated Schiff base ligand L acts as a bidentate ON-donor ligand. Complexation of L increases the inhibitory strength on topoisomerase I activity. Complex 1 could fully inhibit topoisomerase I activity at 250 μM, while L did not show any inhibitory effect on topoisomerase I activity. In addition, L and complex 1 could cleave pBR322 DNA in a concentration and time dependent profile. Surprisingly, L has better DNA cleavage activity than complex 1. The cleavage of DNA by complex 1 is altered in the presence of hydrogen peroxide. Furthermore, L and complex 1 are mildly cytotoxic towards human ovarian cancer A2780 and hepatocellular carcinoma HepG2.
    Matched MeSH terms: DNA Topoisomerases, Type I/metabolism
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