Browse publications by year: 2012

  1. Ya'aini N, Amin NA, Asmadi M
    Bioresour Technol, 2012 Jul;116:58-65.
    PMID: 22609656 DOI: 10.1016/j.biortech.2012.03.097
    Conversion of glucose, empty fruit bunch (efb) and kenaf to levulinic acid over a new hybrid catalyst has been investigated in this study. The characterization and catalytic performance results revealed that the physico-chemical properties of the new hybrid catalyst comprised of chromium chloride and HY zeolite increased the levulinic acid production from glucose compared to the parent catalysts. Optimization of the glucose conversion process using two level full factorial designs (2(3)) with two center points reported 55.2% of levulinic acid yield at 145.2 °C, 146.7 min and 12.0% of reaction temperature, reaction time and catalyst loading, respectively. Subsequently, the potential of efb and kenaf for producing levulinic acid at the optimum conditions was established after 53.2% and 66.1% of efficiencies were reported. The observation suggests that the hybrid catalyst has a potential to be used in biomass conversion to levulinic acid.
    MeSH terms: Acids/metabolism; Analysis of Variance; Biotechnology/methods*; Catalysis; Differential Thermal Analysis; Fruit/chemistry; Glucose/metabolism; Levulinic Acids/metabolism*; Lignin/metabolism*; Models, Biological; Temperature; Thermogravimetry; Time Factors; Biomass*; Hibiscus/chemistry
  2. Gan HM, Shahir S, Yahya A
    Microbiology (Reading), 2012 Aug;158(Pt 8):1933-1941.
    PMID: 22609751 DOI: 10.1099/mic.0.059550-0
    The gene coding for the oxygenase component, sadA, of 4-aminobenzenesulfonate (4-ABS) 3,4-dioxygenase in Hydrogenophaga sp. PBC was previously identified via transposon mutagenesis. Expression of wild-type sadA in trans restored the ability of the sadA mutant to grow on 4-ABS. The inclusion of sadB and sadD, coding for a putative glutamine-synthetase-like protein and a plant-type ferredoxin, respectively, further improved the efficiency of 4-ABS degradation. Transcription analysis using the gfp promoter probe plasmid showed that sadABD was expressed during growth on 4-ABS and 4-sulfocatechol. Heterologous expression of sadABD in Escherichia coli led to the biotransformation of 4-ABS to a metabolite which shared a similar retention time and UV/vis profile with 4-sulfocatechol. The putative reductase gene sadC was isolated via degenerate PCR and expression of sadC and sadABD in E. coli led to maximal 4-ABS biotransformation. In E. coli, the deletion of sadB completely eliminated dioxygenase activity while the deletion of sadC or sadD led to a decrease in dioxygenase activity. Phylogenetic analysis of SadB showed that it is closely related to the glutamine-synthetase-like proteins involved in the aniline degradation pathway. This is the first discovery, to our knowledge, of the functional genetic components for 4-ABS aromatic ring hydroxylation in the bacterial domain.
    MeSH terms: Bacterial Proteins/genetics*; Bacterial Proteins/metabolism; Cloning, Molecular*; Molecular Sequence Data; Phylogeny; Sulfanilic Acids/metabolism*; Comamonadaceae/classification; Comamonadaceae/enzymology*; Comamonadaceae/genetics; Dioxygenases/genetics*; Dioxygenases/metabolism
  3. Manaharan T, Palanisamy UD, Ming CH
    Molecules, 2012;17(5):5915-23.
    PMID: 22609782 DOI: 10.3390/molecules17055915
    Preliminary investigations on 14 plant extracts (obtained by ethanolic and aqueous extraction) identified those having high antioxidant and a significant total phenolic content. Antihyperglycemic, α-amylase and α-glucosidase inhibition activities were also observed. A correlation between the antihyperglycemic activity, total phenolic content and antioxidant (DPPH scavenging) activity was established. To further substantiate these findings, the possibility of tannins binding non-specifically to enzymes and thus contributing to the antihyperglycemic activity was also investigated. Our study clearly indicated that the antihyperglycemic activity observed in the plant extracts was indeed not due to non-specific tannin absorption.
    MeSH terms: alpha-Amylases/metabolism; alpha-Glucosidases/metabolism; Antioxidants/pharmacology*; Antioxidants/chemistry; Enzyme Inhibitors/pharmacology; Enzyme Inhibitors/chemistry; Hypoglycemic Agents/pharmacology*; Hypoglycemic Agents/chemistry; Malaysia; Phenols/chemistry; Plant Extracts/pharmacology*; Plant Extracts/chemistry; Protein Binding; Tannins/metabolism
  4. Gwaram NS, Ali HM, Khaledi H, Abdulla MA, Hadi AH, Lin TK, et al.
    Molecules, 2012 May 18;17(5):5952-71.
    PMID: 22609786 DOI: 10.3390/molecules17055952
    A series of Schiff bases derived from 2-acetylpyridne and their metal complexes were characterized by elemental analysis, NMR, FT-IR and UV-Vis spectral studies. The complexes were screened for anti-bacterial activity against Methicillin-resistant Staphylococcus aureus (MRSA), Acinetobacter baumanni (AC), Klebsiella pneumonie (KB) and Pseudomonas aeruginosa (PA) using the disc diffusion and micro broth dilution assays. Based on the overall results, the complexes showed the highest activities against MRSA while a weak antibacterial activity was observed against A. baumanii and P. aeruginosa.
    MeSH terms: Anti-Bacterial Agents/pharmacology*; Anti-Bacterial Agents/chemistry; Bacteria/drug effects*; Microbial Sensitivity Tests; Pyridines/chemistry*; Schiff Bases/pharmacology; Schiff Bases/chemistry; Molecular Structure; Coordination Complexes/chemistry*
  5. Regueiro M, Rivera L, Chennakrishnaiah S, Popovic B, Andjus S, Milasin J, et al.
    Gene, 2012 Aug 10;504(2):296-302.
    PMID: 22609956 DOI: 10.1016/j.gene.2012.04.093
    One of the primary unanswered questions regarding the dispersal of Romani populations concerns the geographical region and/or the Indian caste/tribe that gave rise to the proto-Romani group. To shed light on this matter, 161 Y-chromosomes from Roma, residing in two different provinces of Serbia, were analyzed. Our results indicate that the paternal gene pool of both groups is shaped by several strata, the most prominent of which, H1-M52, comprises almost half of each collection's patrilineages. The high frequency of M52 chromosomes in the two Roma populations examined may suggest that they descend from a single founder that has its origins in the Indian subcontinent. Moreover, when the Y-STR profiles of haplogroup H derived individuals in our Roma populations were compared to those typed in the South Indian emigrants from Malaysia and groups from Madras, Karnataka (Lingayat and Vokkaliga castes) and tribal Soligas, sharing of the two most common haplotypes was observed. These similarities suggest that South India may have been one of the contributors to the proto-Romanis. European genetic signatures (i.e., haplogroups E1b1b1a1b-V13, G2a-P15, I-M258, J2-M172 and R1-M173), on the other hand, were also detected in both groups, but at varying frequencies. The divergent European genetic signals in each collection are likely the result of differential gene flow and/or admixture with the European host populations but may also be attributed to dissimilar endogamous practices following the initial founder effect. Our data also support the notion that a number of haplogroups including G2a-P15, J2a3b-M67(xM92), I-M258 and E1b1b1-M35 were incorporated into the proto-Romani paternal lineages as migrants moved from northern India through Southwestern Asia, the Middle East and/or Anatolia into the Balkans.
    MeSH terms: Ethnic Groups*; Haplotypes*; Humans; India; Microsatellite Repeats/genetics*
  6. Hajeb P, Jinap S, Ismail A, Mahyudin NA
    PMID: 22610296 DOI: 10.1007/978-1-4614-3414-6_2
    Although several studies have been published on levels of mercury contamination of the environment, and of food and human tissues in Peninsular Malaysia, there is a serious dearth of research that has been performed in East Malaysia (Sabah and Sarawak). Industry is rapidly developing in East Malaysia, and, hence, there is a need for establishing baseline levels of mercury contamination in environmental media in that part of the country by performing monitoring studies. Residues of total mercury and inorganic in food samples have been determined in nearly all previous studies that have been conducted; however, few researchers have analyzed samples for the presence of methlymercury residues. Because methylmercury is the most toxic form of mercury, and because there is a growing public awareness of the risk posed by methylmercury exposure that is associated with fish and seafood consumption, further monitoring studies on methylmercury in food are also essential. From the results of previous studies, it is obvious that the economic development in Malaysia, in recent years, has affected the aquatic environment of the country. Primary areas of environmental concern are centered on the rivers of the west Peninsular Malaysian coast, and the coastal waters of the Straits of Malacca, wherein industrial activities are rapidly expanding. The sources of existing mercury input to both of these areas of Malaysia should be studied and identified. Considering the high levels of mercury that now exists in human tissues, efforts should be continued, and accelerated in the future, if possible, to monitor mercury contamination levels in the coastal states, and particularly along the west Peninsular Malaysian coast. Most studies that have been carried out on mercury residues in environmental samples are dated, having been conducted 20-30 years ago; therefore, the need to collect much more and more current data is urgent. Furthermore, establishing baseline levels of mercury exposure to humans in Malaysia will be useful in establishing the levels at which detrimental effects in both humans and marine life may occur, and therefore the levels at which warning should be raised or limits established. In particular, we believe that two or three monitoring centers should be established in Peninsular Malaysia, and one in East Malaysia for the specific purpose of monitoring for the presence of hazardous environmental chemicals, and particularly monitoring for heavy metals such as mercury that reach food that is subject to consistent human consumption.
    MeSH terms: Drug Contamination*; Environmental Monitoring; Food Contamination*; Humans; Malaysia; Mercury/toxicity*; Water Pollutants, Chemical/toxicity*; Geologic Sediments/analysis
  7. Salam MA, Affan MA, Saha R, Ahmad FB, Sam N
    Bioinorg Chem Appl, 2012;2012:698491.
    PMID: 22611347 DOI: 10.1155/2012/698491
    Five new organotin(IV) complexes of 2-hydroxyacetophenone-2-methylphenylthiosemicarbazone [H(2)dampt, (1)] with formula [RSnCl(n-1)(dampt)] (where R = Me, n = 2 (2); R = Bu, n = 2 (3); R = Ph, n = 2 (4); R = Me(2), n = 1 (5); R = Ph(2), n = 1 (6)) have been synthesized by direct reaction of H(2)dampt (1) with organotin(IV) chloride(s) in absolute methanol. The ligand (1) and its organotin(IV) complexes (2-6) were characterized by CHN analyses, molar conductivity, UV-Vis, FT-IR, (1)H, (13)C, and (119)Sn NMR spectral studies. H(2)dampt (1) is newly synthesized and has been structurally characterized by X-ray crystallography. Spectroscopic data suggested that H(2)dampt (1) is coordinated to the tin(IV) atom through the thiolate-S, azomethine-N, and phenoxide-O atoms; the coordination number of tin is five. The in vitro antibacterial activity has been evaluated against Staphylococcus aureus, Enterobacter aerogenes, Escherichia coli, and Salmonella typhi. The screening results have shown that the organotin(IV) complexes (2-6) have better antibacterial activities and have potential as drugs. Furthermore, it has been shown that diphenyltin(IV) derivative (6) exhibits significantly better activity than the other organotin(IV) derivatives (2-5).
  8. Nadia ME, Nazrun AS, Norazlina M, Isa NM, Norliza M, Ima Nirwana S
    Adv Pharmacol Sci, 2012;2012:706905.
    PMID: 22611381 DOI: 10.1155/2012/706905
    Osteoporosis is characterized by skeletal degeneration with low bone mass and destruction of microarchitecture of bone tissue which is attributed to various factors including inflammation. Women are more likely to develop osteoporosis than men due to reduction in estrogen during menopause which leads to decline in bone-formation and increase in bone-resorption activity. Estrogen is able to suppress production of proinflammatory cytokines such as IL-1, IL-6, IL-7, and TNF-α. This is why these cytokines are elevated in postmenopausal women. Studies have shown that estrogen reduction is able to stimulate focal inflammation in bone. Labisia pumila (LP) which is known to exert phytoestrogenic effect can be used as an alternative to ERT which can produce positive effects on bone without causing side effects. LP contains antioxidant as well as exerting anti-inflammatory effect which can act as free radical scavenger, thus inhibiting TNF-α production and COX-2 expression which leads to decline in RANKL expression, resulting in reduction in osteoclast activity which consequently reduces bone loss. Hence, it is the phytoestrogenic, anti-inflammatory, and antioxidative properties that make LP an effective agent against osteoporosis.
    MeSH terms: Osteoporosis*; Plants, Medicinal
  9. Sani MH, Zakaria ZA, Balan T, Teh LK, Salleh MZ
    PMID: 22611437 DOI: 10.1155/2012/890361
    Muntingia calabura L. (family Elaeocarpaceae) has been traditionally used to relieve various pain-related ailments. The present study aimed to determine the antinociceptive activity of methanol extract of M. calabura leaves (MEMC) and to elucidate the possible mechanism of antinociception involved. The in vivo chemicals (acetic acid-induced abdominal constriction and formalin-, capsaicin-, glutamate-, serotonin-induced paw licking test) and thermal (hot plate test) models of nociception were used to evaluate the extract antinociceptive activity. The extract (100, 250, and 500 mg/kg) was administered orally 60 min prior to subjection to the respective test. The results obtained demonstrated that MEMC produced significant (P < 0.05) antinociceptive response in all the chemical- and thermal-induced nociception models, which was reversed after pretreatment with 5 mg/kg naloxone, a non-selective opioid antagonist. Furthermore, pretreatment with L-arginine (a nitric oxide (NO) donor), N(G)-nitro-L-arginine methyl esters (L-NAME; an inhibitor of NO synthase (NOS)), methylene blue (MB; an inhibitor of cyclic-guanosine monophosphate (cGMP) pathway), or their combination also caused significant (P < 0.05) change in the intensity of the MEMC antinociception. In conclusion, the MEMC antinociceptive activity involves activation of the peripheral and central mechanisms, and modulation via, partly, the opioid receptors and NO/cGMP pathway.
    MeSH terms: Methanol; Capsaicin; Constriction; Formaldehyde; Guanosine Monophosphate; Methylene Blue; Naloxone; Nitric Oxide; Receptors, Opioid; Serotonin; Glutamic Acid; NG-Nitroarginine Methyl Ester; Acetic Acid; Elaeocarpaceae; Nociception
  10. Nor-Masniwati S, Zunaina E, Azhany Y
    Case Rep Ophthalmol Med, 2012;2012:606741.
    PMID: 22611511 DOI: 10.1155/2012/606741
    A 23-year-old Malay man presented with headache for one-month duration. It was associated with painless blurring of vision of the right eye. He had loss of appetite and reduced weight but no night sweats or hemoptysis. His visual acuity on the right eye was 6/45 and improved to 6/15 with pinhole. Right fundus examination revealed a choroidal tuberculoma located at one disc diameter away from optic disc superiorly with mild vitritis. Systemic examinations revealed no significant finding. Mantoux test reading was 22 mm with erythrocyte sedimentation rate that was 14 mm/h. Other blood investigations were negative with normal chest radiography. The computerized tomography scan of the brain revealed multiple cerebral abscesses. A clinical diagnosis of right ocular tuberculosis with multiple cerebral abscesses was made. He was treated with antituberculosis chemotherapy for one year which divided into intensive phase for three months and maintenance phase for nine months. Cerebral abscesses resolved after three months of antituberculosis drugs and at one-year follow-up, and the choroidal tuberculoma resolved completely with scar formation and significant macular striae.
    MeSH terms: Adult; Antitubercular Agents; Appetite; Blood Sedimentation; Choroid; Cicatrix; Follow-Up Studies; Fundus Oculi; Hemoptysis; Humans; Malaysia; Male; Optic Disk; Reading; Sweat; Tuberculoma; Tuberculosis, Ocular; Visual Acuity; Young Adult
  11. Edwards DP, Woodcock P, Edwards FA, Larsen TH, Hsu WW, Benedick S, et al.
    Ecol Appl, 2012 Mar;22(2):561-71.
    PMID: 22611854 DOI: 10.1890/11-1362.1
    A key driver of rain forest degradation is rampant commercial logging. Reduced-impact logging (RIL) techniques dramatically reduce residual damage to vegetation and soils, and they enhance the long-term economic viability of timber operations when compared to conventionally managed logging enterprises. Consequently, the application of RIL is increasing across the tropics, yet our knowledge of the potential for RIL also to reduce the negative impacts of logging on biodiversity is minimal. We compare the impacts of RIL on birds, leaf-litter ants, and dung beetles during a second logging rotation in Sabah, Borneo, with the impacts of conventional logging (CL) as well as with primary (unlogged) forest. Our study took place 1-8 years after the cessation of logging. The species richness and composition of RIL vs. CL forests were very similar for each taxonomic group. Both RIL and CL differed significantly from unlogged forests in terms of bird and ant species composition (although both retained a large number of the species found in unlogged forests), whereas the composition of dung beetle communities did not differ significantly among forest types. Our results show little difference in biodiversity between RIL and CL over the short-term. However, biodiversity benefits from RIL may accrue over longer time periods after the cessation of logging. We highlight a severe lack of studies investigating this possibility. Moreover, if RIL increases the economic value of selectively logged forests (e.g., via REDD+, a United Nations program: Reducing Emissions from Deforestation and Forest Degradation in Developing Countries), it could help prevent them from being converted to agricultural plantations, which results in a tremendous loss of biodiversity.
    MeSH terms: Animals; Ants/physiology; Beetles/physiology; Birds/physiology; Borneo; Conservation of Natural Resources/methods*; Environmental Monitoring; Population Dynamics; Forestry*; Biodiversity*
  12. Al-Atabi M, Espino DM, Hukins DW, Buchan KG
    Proc Inst Mech Eng H, 2012 Apr;226(4):275-87.
    PMID: 22611868
    Repair of the mitral valve is defined (loosely) as a procedure that alters the valve structure, without replacement, enabling the natural valve itself to continue to perform under the physical conditions to which it is exposed. As the mitral valve is driven by flow and pressure, it should be feasible to analyse and assess its function, failure and repair as a mechanical system. This article reviews the current state of mechanical evaluation of surgical repairs of the failed mitral valve of the heart. This review describes the anatomy and physiology of the mitral valve, followed by the failure of the mitral valve from a mechanical point of view. The surgical methods used to repair failed valves are introduced, while the use of engineering analysis to aid understanding of mitral valve repair is also reviewed. Finally, a section on recommendations for development and future uses of engineering techniques to surgical repair are presented.
    MeSH terms: Humans; Mitral Valve/physiopathology*; Mitral Valve/surgery*; Mitral Valve Insufficiency/physiopathology*; Mitral Valve Insufficiency/surgery*; Suture Techniques*; Reconstructive Surgical Procedures/instrumentation; Reconstructive Surgical Procedures/methods*; Mitral Valve Annuloplasty/instrumentation*; Mitral Valve Annuloplasty/methods
  13. Khoo TK, Noordin R, Santhanam A
    Indian J Exp Biol, 2012 Apr;50(4):256-64.
    PMID: 22611913
    A rapid antibody detection test is very useful for the detection of lymphatic filariasis, especially for certification and surveillance of post-mass drug administration. panLF Rapid kit is suitable for this purpose since it can detect all species of lymphatic filaria. It is based on the detection of anti-filarial IgG4 antibodies that react with recombinant B. malayi antigens, BmR1 and BmSXP. There is an increase demand for the test due to its attributes of being rapid, sensitive and specific results, as well as its field-applicability. The main aim of this paper is to obtain high recovery and purity of recombinant antigen BmSXP via a modified method of immobilized metal affinity chromatography (IMAC). The highest product yield of 11.82 mg/g dry cell weight (DCW) was obtained when IMAC was performed using the optimized protocol of 10 mM imidazole concentration in lysis buffer, 30 mM imidazole concentration in wash buffer, and 10 column volume wash buffer containing 300 mM salt concentration. This gave a 54% protein recovery improvement over the manufacturer's protocol which recorded a product yield of only 7.68 mg/g DCW. The recovered BmSXP recombinant antigen showed good western blot reactivity, high sensitivity (31/32, 97%) and specificity (32/32, 100%) in ELISA, thus attesting to its good purity and quality.
    MeSH terms: Antigens, Helminth/analysis*; Antigens, Helminth/isolation & purification; Chromatography, Affinity; Electrophoresis, Polyacrylamide Gel; Elephantiasis, Filarial/immunology*; Enzyme-Linked Immunosorbent Assay; Humans; Recombinant Proteins/analysis; Recombinant Proteins/isolation & purification; Blotting, Western
  14. Rashed AN, Wong IC, Cranswick N, Hefele B, Tomlin S, Jackman J, et al.
    Drug Saf, 2012 Jun 1;35(6):481-94.
    PMID: 22612852 DOI: 10.2165/11597920-000000000-00000
    Background: A previous meta-analysis reported that 9.5% of hospitalized children suffered from an adverse drug reaction (ADR); however, reported incidences among studies varied.

    Objective: To enhance the knowledge of ADRs in paediatric hospitalized patients at a global level we investigated the incidence and characteristics of ADRs in hospitalized children in European and non-European countries.

    Methods: A prospective observational cohort study was conducted in academic and non-academic hospitals in five countries: Australia, Germany, Hong Kong, Malaysia and the UK. Children aged 0-18 years admitted during a 3-month period (between 1 October 2008 and 31 December 2009) were recruited. The main outcome measures were incidence, causality and outcome of ADRs.

    Results: A total of 1278 patients (1340 admissions) were included [Australia n = 146 (149 admissions), Germany n = 376 (407), Hong Kong n = 143 (149), Malaysia n = 300 (314) and the UK n = 313 (321)]. The median age was 2 years (interquartile range [IQR] 0-7). Patients received a total of 5367 drugs (median 3; IQR 2-5) and median length of hospital stay was 4 days (IQR 3-7). A total of 380 ADRs were identified in 211 patients. The resultant ADR incidence of 16.5% (95% CI 14.5, 18.7) varied significantly between countries (p < 0.001). The highest incidences were observed in Malaysia and the UK. 65.3% (n = 248) of ADRs were found to be probable, and 24% of the ADRs were serious, with one being fatal.

    Conclusions: By comparing data from five countries in Europe, Asia and Australia we have shown that the incidence of ADRs in hospitalized children is at least as high as incidences published in adults. However, the variation between countries was mainly due to different populations and treatment strategies. Particular attention should be given to opioid use in hospitalized children.
    MeSH terms: Adolescent; Asia; Australia; Child; Child, Preschool; Europe; Female; Hospitalization/statistics & numerical data*; Humans; Infant; Length of Stay; Male; Prospective Studies; Cohort Studies; Incidence; Adverse Drug Reaction Reporting Systems/statistics & numerical data*; Drug-Related Side Effects and Adverse Reactions*
  15. Chan KM, Hamzah R, Rahaman AA, Jong VY, Khong HY, Rajab NF, et al.
    Food Chem Toxicol, 2012 Aug;50(8):2916-22.
    PMID: 22613213 DOI: 10.1016/j.fct.2012.04.048
    Inophyllin A (INO-A), a pyranoxanthone isolated from the roots of Calophyllum inophyllum represents a new xanthone with potential chemotherapeutic activity. In this study, the molecular mechanism of INO-A-induced cell death was investigated in Jurkat T lymphoblastic leukemia cells. Assessment of phosphatidylserine exposure confirmed apoptosis as the primary mode of cell death in INO-A-treated Jurkat cells. INO-A treatment for only 30 min resulted in a significant increase of tail moment which suggests that DNA damage is an early apoptotic signal. Further flow cytometric assessment of the superoxide anion level confirmed that INO-A induced DNA damage was mediated with a concomitant generation of reactive oxygen species (ROS). Investigation on the thiols revealed an early decrease of free thiols in 30 min after 50 μM INO-A treatment. Using tetramethylrhodamine ethyl ester, a potentiometric dye, the loss of mitochondrial membrane potential (MPP) was observed in INO-A-treated cells as early as 30 min. The INO-A-induced apoptosis progressed with the simultaneous activation of caspases-2 and -9 which then led to the processing of caspase-3. Taken together, these data demonstrate that INO-A induced early oxidative stress, DNA damage and loss of MMP which subsequently led to the activation of an intrinsic pathway of apoptosis in Jurkat cells.
    MeSH terms: DNA Damage; Enzyme Activation; Flow Cytometry; Humans; Leukemia, T-Cell/enzymology; Leukemia, T-Cell/metabolism*; Leukemia, T-Cell/pathology; Apoptosis/drug effects*; Reactive Oxygen Species/metabolism; Oxidative Stress/drug effects*; Jurkat Cells; Caspases/metabolism; Xanthones/pharmacology*
  16. Zainal SA, Md Daud MK, Abd Rahman N, Zainuddin Z, Alwi Z
    Int J Pediatr Otorhinolaryngol, 2012 Aug;76(8):1175-9.
    PMID: 22613756 DOI: 10.1016/j.ijporl.2012.04.027
    To identify the mutations in the GJB2 gene and to determine its association with non-syndromic hearing loss in Malays.
    MeSH terms: Cross-Sectional Studies; DNA Mutational Analysis; Genotype; Humans; Malaysia/epidemiology; Mutation*; Polymorphism, Genetic; Prevalence; Polymerase Chain Reaction; Connexins/genetics*; Hearing Loss/genetics*; Hearing Loss/epidemiology
  17. Helal MH, Al-Mudaris ZA, Al-Douh MH, Osman H, Wahab HA, Alnajjar BO, et al.
    Int J Oncol, 2012 Aug;41(2):504-10.
    PMID: 22614449 DOI: 10.3892/ijo.2012.1491
    Molecules that target the deoxyribonucleic acid (DNA) minor groove are relatively sequence specific and they can be excellent carrier structures for cytotoxic chemotherapeutic compounds which can help to minimize side effects. Two novel isomeric derivatives of diaminobenzene Schiff base [N,N'-bis (2-hydroxy-3-methoxybenzylidene)-1,2-diaminobenzene (2MJ) and N,N'-bis(2-hydroxy-3-methoxybenzylidene)-1,3-diaminobenzene (2MH)] were analyzed for their DNA minor groove binding (MGB) ability using viscometry, UV and fluorescence spectroscopy, computational modeling and clonogenic assay. The result shows that 2MJ and 2MH are strong DNA MGBs with the latter being more potent. 2MH can form interstrand hydrogen bond linkages at its oxygens with N3 of adenines. Changing the 2-hydroxy-3-methoxybenzylidene binding position to the 1,3 location on the diaminobenzene structure (2MJ) completely removed any viable hydrogen bond formation with the DNA and caused significant decrease in binding strength and minor groove binding potency. Neither compound showed any significant cytotoxicity towards human breast, colon or liver cancer cell lines.
    MeSH terms: Adsorption; Binding, Competitive; Cell Survival/drug effects; Computer Simulation; DNA/chemistry*; Drug Carriers/pharmacology; Drug Carriers/chemistry*; Guaiacol/analogs & derivatives*; Guaiacol/pharmacology; Guaiacol/chemistry; Humans; Hydrogen Bonding; Models, Molecular; Nucleic Acid Conformation; Schiff Bases/pharmacology; Schiff Bases/chemistry*; Viscosity; Inhibitory Concentration 50; Cell Line, Tumor
  18. Pua CH, Ahmad H, Harun SW, De La Rue RM
    Appl Opt, 2012 May 20;51(15):2772-7.
    PMID: 22614578 DOI: 10.1364/AO.51.002772
    The idea of applying a simple Fabry-Perot fiber laser (FPFL) set-up in a free-running condition as an acoustic sensing medium is proposed. Conventional optical microphone requires a stringently aligned diaphragm to mediate the acoustic impedance mismatch between air and silica fiber. Motivated by the difficulty of optical sensing of airborne acoustic waves, a new sensing method is proposed to sense acoustic waves without the assistance of a diaphragm as transducer. By studying the output power fluctuation of the FPFL, the operating bandwidth and sensitivity of the proposed sensing method are determined. The tunability of the resonant frequency from 5 kHz to 85 kHz allows sensing of acoustic waves in the range of 100 Hz to 100 kHz. Tuning of the resonant frequency can be performed by changing the optical pumping power from as low as 10 mW to 68.5 mW or higher.
    MeSH terms: Acoustics; Diaphragm; Dietary Fiber; Silicon Dioxide; Sound; Transducers; Electric Impedance
  19. Hashim NM, Rahmani M, Ee GC, Sukari MA, Yahayu M, Amin MA, et al.
    Molecules, 2012;17(5):6071-82.
    PMID: 22614861 DOI: 10.3390/molecules17056071
    One of the most promising plants in biological screening test results of thirteen Artocarpus species was Artocarpus obtusus FM Jarrett and detailed phytochemical investigation of powdered dried bark of the plant has led to the isolation and identification of three xanthones; pyranocycloartobiloxanthone A (1), dihydroartoindonesianin C (2) and pyranocycloartobiloxanthone B (3). These compounds were screened for antioxidant, antimicrobial and tyrosinase inhibitory activities. Pyranocycloartobiloxanthone A (1) exhibited a strong free radical scavenger towards DPPH free radicals with IC50 value of 2 µg/mL with prominent discoloration observed in comparison with standard ascorbic acid, α-tocopherol and quercetin, The compound also exhibited antibacterial activity against methicillin resistant Staphylococcus aureus (ATCC3359) and Bacillus subtilis (clinically isolated) with inhibition zone of 20 and 12 mm, respectively. However the other two xanthones were found to be inactive. For the tyrosinase inhibitory activity, again compound (1) displayed strong activity comparable with the standard kojic acid.
    MeSH terms: Anti-Infective Agents/pharmacology*; Anti-Infective Agents/chemistry; Antioxidants/pharmacology*; Antioxidants/chemistry; Bacteria/drug effects; Enzyme Inhibitors/pharmacology*; Enzyme Inhibitors/chemistry; Fungi/drug effects; Plant Extracts/pharmacology*; Plant Extracts/chemistry; Monophenol Monooxygenase/antagonists & inhibitors*; Inhibitory Concentration 50; Artocarpus/chemistry*; Xanthones/isolation & purification; Xanthones/pharmacology*; Xanthones/chemistry
  20. Yeoh AE, Ariffin H, Chai EL, Kwok CS, Chan YH, Ponnudurai K, et al.
    J Clin Oncol, 2012 Jul 1;30(19):2384-92.
    PMID: 22614971 DOI: 10.1200/JCO.2011.40.5936
    PURPOSE: To improve treatment outcome for childhood acute lymphoblastic leukemia (ALL), we designed the Malaysia-Singapore ALL 2003 study with treatment stratification based on presenting clinical and genetic features and minimal residual disease (MRD) levels measured by polymerase chain reaction targeting a single antigen-receptor gene rearrangement.
    PATIENTS AND METHODS: Five hundred fifty-six patients received risk-adapted therapy with a modified Berlin-Frankfurt-Münster-ALL treatment. High-risk ALL was defined by MRD ≥ 1 × 10(-3) at week 12 and/or poor prednisolone response, BCR-ABL1, MLL gene rearrangements, hypodiploid less than 45 chromosomes, or induction failure; standard-risk ALL was defined by MRD ≤ 1 × 10(-4) at weeks 5 and 12 and no extramedullary involvement or high-risk features. Intermediate-risk ALL included all remaining patients.
    RESULTS: Patients who lacked high-risk presenting features (85.7%) received remission induction therapy with dexamethasone, vincristine, and asparaginase, without anthracyclines. Six-year event-free survival (EFS) was 80.6% ± 3.5%; overall survival was 88.4% ± 3.1%. Standard-risk patients (n = 172; 31%) received significantly deintensified subsequent therapy without compromising EFS (93.2% ± 4.1%). High-risk patients (n = 101; 18%) had the worst EFS (51.8% ± 10%); EFS was 83.6% ± 4.9% in intermediate-risk patients (n = 283; 51%).
    CONCLUSION: Our results demonstrate significant progress over previous trials in the region. Three-drug remission-induction therapy combined with MRD-based risk stratification to identify poor responders is an effective strategy for childhood ALL.
    MeSH terms: Adolescent; Antineoplastic Combined Chemotherapy Protocols/administration & dosage; Antineoplastic Combined Chemotherapy Protocols/therapeutic use; Child; Child, Preschool; Female; Humans; Infant; Infant, Newborn; Malaysia; Male; Prognosis; Singapore; Bone Marrow Transplantation; Treatment Outcome; Neoplasm, Residual/drug therapy; Neoplasm, Residual/genetics; Neoplasm, Residual/therapy*; Disease-Free Survival; Precursor Cell Lymphoblastic Leukemia-Lymphoma/drug therapy; Precursor Cell Lymphoblastic Leukemia-Lymphoma/genetics; Precursor Cell Lymphoblastic Leukemia-Lymphoma/therapy*
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