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  1. Synthesis of natural starch from Elaeis guineensis trunk biomass applying bisulphite steeping method: Optimization by RSM
    Ahmed Z, Yusoff MS, N H MK, Abdul Aziz H
    J Air Waste Manag Assoc, 2022 01;72(1):116-130.
    PMID: 33872123 DOI: 10.1080/10962247.2021.1919240
    A massive quantity of Elaeis guineensis (oil palm) trunk biomass, containing a significant amount of natural starch, is available in Malaysia as biowaste because of annual replantation. The efficient extraction of this starch (carbohydrate polymer) would be worthwhile concerning the environmental sustainability and economy through conversion to bioresources. This study investigated the effectiveness of the bisulfite steeping method for starch synthesis from oil palm trunk (OPT) biowaste. The central composite design (CCD) of Design-Expert software executed an experimental model design, data analysis, evaluated the impacts of process variables and their interaction through response surface methodology to optimize the bisulfite steeping method for starch synthesis. The developed quadratic models for four factors (strength of sodium bisulfite solution, steeping hour, mixing ratio with the bisulfite solution, and ultrapure water) and one response (%Yield) demonstrated that a significant starch yield (13.54%) is achievable employing 0.74% bisulfite solution, 5.6 steeping hours, for 1.6 and 0.6 mixing ratio with the bisulfite solution and ultrapure water respectively. Experimental outcomes were consistent with the predicted model, which eventually sustains the significance of this method. Malvern Zetasizer test revealed a bimodal granular distribution for starch, with 7.15 µm of hydrodynamic size. Starch morphology was determined by scanning electron microscopy. X-ray diffraction investigation exhibits an A-type model, specifying persistent characteristics, while FTIR confirms the presence of hydroxyl, carboxylic, and phenolic groups like other cereal starches.Implications: Malaysia is the 2nd largest palm oil exporter in the world. About 110 million tons of palm oil trunk (OPT) biomass is available annually during replanting activities. Modification of bio-wastes into a beneficial form (only 22% presently) like starch extraction would ensure potential reuse as a natural coagulant for wastewater and leachate treatment, food source, adhesives towards boosting the country's economy by sustainable waste management. The current study achieved better starch yield (13.54%) than previous, from the OPT biomass through the novel bisulfite steeping method. Therefore, this method will ascertain the effective implication of numerous economic activities.
    Matched MeSH terms: Sulfites
  2. Fulltext Effectiveness of ascorbic acid and sodium metabisulfite as anti-browning agent and antioxidant on green coconut water (Cocos nucifera) subjected to elevated thermal processing
    Tan, T.C., Cheng, L.H., Bhat, R., Rusul, G., Easa, A.M.
    International Food Research Journal, 2015;22(2):631-637.
    MyJurnal
    Thermal processing of green coconut water (GCW) caused non-enzymic browning and development of rancidity. Effect of the addition of several combinations of ascorbic acid (AA) (0 to 100 ppm) and sodium metabisulfite (SMB) (0 to 30 ppm) on brown discolouration and rancidity of GCW during elevated thermal processing (121°C for 5 min at 15 psi) was investigated. Addition of AA and/or SMB significantly (P
    Matched MeSH terms: Sulfites
  3. Structural properties and hydrolysability of recycled poplar residues (Populus L.): Effects of two-step acetic acid and sodium sulphite pre-treatment
    Chu J, Li S, Chen N, Wen P, Sonne C, Ma NL
    Chemosphere, 2022 Mar;291(Pt 1):132679.
    PMID: 34718007 DOI: 10.1016/j.chemosphere.2021.132679
    Poplar trees rapidly yield wood and are therefore suitable as a biofuel feedstock; however, the quality of poplar is modest, and the profitability of poplar cultivation depends on the efficiency of the harvesting process. This study offers a simple and sustainable technique to harvest lignocellulosic resources from poplar for bioethanol production. The proposed two-step pretreatment method increased the surface lignin content and decreased the surface polysaccharide content. The cellulose content increased to 54.9% and the xylan content decreased to 6.7% at 5% AC. The cellulose yield of poplar residues (Populus L.) reached 65.5% by this two-step acetic acid (AC) and sodium sulphite (SS) treatment method. Two-step pretreatment using 5% AC and 4% SS obtained a recovery of nearly 80% of the total available fermentable sugar. The surface characterization showed a higher porosity in treated samples, which improved their hydrolysability. This method decreased the amount of lignin in plant biomass, making it applicable for further wood resource recovery or waste recycling for biorefinery purposes at very low costs.
    Matched MeSH terms: Sulfites
  4. Bisulfite pretreatment changes the structure and properties of oil palm empty fruit bunch to improve enzymatic hydrolysis and bioethanol production
    Tan L, Sun W, Li X, Zhao J, Qu Y, Choo YM, et al.
    Biotechnol J, 2015 Jun;10(6):915-25.
    PMID: 25866127 DOI: 10.1002/biot.201400733
    Bisulfite pretreatment is a proven effective method for improving the enzymatic hydrolysis of empty fruit bunch (EFB) from oil palm for bioethanol production. In this study, we set out to determine the changes that occur in the structure and properties of EFB materials and fractions of hemicellulose and lignin during the bisulfite pretreatment process. The results showed that the crystallinity of cellulose in EFB increased after bisulfite pretreatment, whereas the EFB surface was damaged to various degrees. The orderly structure of EFB, which was maintained by hydrogen bonds, was destroyed by bisulfite pretreatment. Bisulfite pretreatment also hydrolyzed the glycosidic bonds of the xylan backbone of hemicellulose, thereby decreasing the molecular weight and shortening the xylan chains. The lignin fractions obtained from EFB and pretreated EFB were typically G-S lignin, and with low content of H units. Meanwhile, de-etherification occurred at the β-O-4 linkage, which was accompanied by polymerization and demethoxylation as a result of bisulfite pretreatment. The adsorption ability of cellulase differed for the various lignin fractions, and the water-soluble lignin fractions had higher adsorption capacity on cellulase than the milled wood lignin. In general, the changes in the structure and properties of EFB provided insight into the benefits of bisulfite pretreatment.
    Matched MeSH terms: Sulfites/chemistry*
  5. Separation of geraniol from citronellol by selective oxidation of geraniol to geranial
    Jalifah binti Latip, Daniel Chong Jun Weng, Siti Aishah binti Hasbullah, Harjono Sastrohamidjojo
    Sains Malaysiana, 2015;44:1183-1188.
    Rhodinol is a mixture of geraniol and citronellol. It is the second fraction in fractional distillation of commercially grown Cymbopogon nardus. The physical and chemical similarities of these two compounds made them inseparable. The individual use of each compound is of great importance. A selective oxidation (hydrogen peroxide activated by platinum black) of geraniol (in rhodinol) to geranial was done while remaining citronellol intact in order to separate the two compounds into different chemical functionality. A yield of 81% geranial achieved while minimizing citronellal formation from citronellol to 17%. Chemical separation using sodium hydrogen sulfite (NaHSO3) was done to separate the aldehydes from the unreacted citronellol. Purification using fractional distillation was done to obtain pure geraniol and remove minor fraction of citronellal.
    Matched MeSH terms: Sulfites
  6. Clostridium perfringens and sulphite reducing clostridia densities in selected tropical Malaysian rivers
    Lee FC, Hakim SL, Kamaluddin MA, Thong KL
    Southeast Asian J. Trop. Med. Public Health, 2012 Jan;43(1):129-35.
    PMID: 23082563
    Clostridium perfringens (CP) and sulphite reducing clostridia (SRC) densities in the Selangor River, Bernam River and Tengi River Canal were examined between April 2007 and January 2008. Water samples were taken from two or three locations along each river, using either depth-integration or grab sampling methods. The downstream sampling site of the Selangor River, Rantau Panjang, reported the highest arithmetic mean of CP and SRC densities (583.45 and 8,120.08 cfu/100 ml, respectively). Both CP and SRC densities in the Selangor River increased further downstream, but the reverse was true in the Bernam River. The SRC densities in these rivers were significantly different from each other (p < 0.05) when comparing upstream and downstream results, but CP densities were not significantly different (p > 0.05). SRC densities were significantly correlated (p < 0.05) in different locations along the Selangor River and the Bernam River. The CP densities did not show such pattern (p > 0.05). River discharge had no significant correlation with SRC or CP densities by study site (p > 0.05). Since the Selangor River has a denser human population along its banks, this study confirms CP as a suitable indicator of human fecal contamination. However, tracing CP distribution along the river is more difficult than SRC. To our knowledge, this is the first study of CP and SRC densities from Malaysian rivers. CP densities found in this study were within the range of general water bodies reported from other countries.
    Matched MeSH terms: Sulfites
  7. Fulltext Preparation and thermal behaviour of acrylonitrile (an)/ethyl acrylate (ea) copolymer and acrylonitrile (an)/ethyl acrylate (ea)/fumaronitrile (fn) terpolymer as precursors for carbon fibre
    Siti Nurul Ain Md. Jamil, Rusil Daik, Ishak Ahmad
    Pertanika Journal of Science & Technology, 2010;18(2):-.
    MyJurnal
    Redox polymerization of acrylonitrile (AN) with ethyl acrylate (EA) and fumaronitrile (FN), as comonomer and termonomer respectively, were carried out using sodium bisulfite (SBS) and potassium persulphate (KPS) as initiators at 40°C. The actual composition of monomers in copolymers and terpolymers has been characterized by gas chromatography (GC). The effects of EA and FN on the glass transition temperature (Tg) and stabilization temperature have been studied by Differential Scanning Calorimetry (DSC). The degradation behaviour and char yield were obtained by thermogravimetric analysis. Meanwhile, incorporation of 10 mol% of EA in homoPAN system was found to greatly reduce Tg to 66°C as compared to that of the homoPAN (Tg=105°C). The initial cyclization temperature (Ti) was found to be higher (264°C) in comparison to that of homoPAN (246°C). In addition, the incorporation of EA was also shown to reduce the char yield of copolymer to 40%. When FN was incorporated as termonomer, the char yield of poly(AN/EA/ FN) 90/4/6 increased up to 44% after the heat treatment with the lowest Ti (241°C).
    Matched MeSH terms: Sulfites
  8. Fulltext Microbiological quality of freshwater prawns during storage
    Abu Bakar, F.
    International Food Research Journal, 2008;15(3):258-272.
    MyJurnal
    Microbiological quality analysis of freshwater prawns from three sampling sites in Peninsular Malaysia viz: Site 1- Kg. Jumbang, Negri Sembilan; Site 2- Kg. Cangkat Tin, Perak and Site 3- Kg. Cenderiang, Perak for total mesophilic and psychrophilic aerobic counts, proteolytic bacterial counts, histamine producing bacteria, cadaverine producing bacteria and putrescine producing bacteria in the prawns and pond water for the three sites showed that the microbiological quality of freshwater prawns is related to the microflora of pond water in which they were grown. The initial bacterial counts indicated the values were in the range of log 4+ CFU/g for all samples. Total mesophilic and psychrophilic counts of the head regions were higher than that of the body regions for all prawn samples and types of growth media tested. All samples showed an increase in counts with time and temperature of storage up to log 7+ CFU/g for mesophilic counts after 12 hours at ambient, 6 days at 10 ± 2°C and 12 days at iced storage. The samples from Site 2 had relatively higher counts compared to the other two sites which correlated well with the levels determined in the pond water. Similar trends were observed for psychrophilic counts but at lower values for the different types of media studied.
    Effects of preservatives on quality changes and shelf life of shrimp during iced storage indicated that boric acid, lactic acid and sodium metabisulphite managed to inhibit psychrophilic bacteria and biogenic amines formation in prawns while maintaining the mesophilic counts at lower levels during iced storage.
    Matched MeSH terms: Sulfites
  9. Fulltext Partial purification and characterization of polyphenol oxidase from round brinjal (S. melongena var. depressum)
    Ng, A.W.R., Wong, C.W.
    International Food Research Journal, 2015;22(2):826-831.
    MyJurnal
    Polyphenol oxidase (PPO) catalyzes the conversion of phenolic compounds into o-quinones which will lead to food browning. This phenomenon causes huge implications on food industries, as it degrades food quality over time. By combining both ammonium sulphate precipitation and gel filtration chromatography, PPO was partially purified up to 5.26-fold with 11.23% yield. The enzyme activity was 5120 EU/mL using 4-methylcatechol as substrate. Maximal PPO activity was found at 30oC, pH 5.0 for 4-methylcatechol and 40°C, pH 6.0 for catechol. The PPO showed a higher affinity towards 4-methylcatechol but higher thermal stability when reacting with catechol. The Km and Vmax values were 5.00 mM, 2000 EU/ml for 4-methylcatechol and 10.79 mM, 526.32 EU/ml for catechol. Energy for inactivation (Ea) obtained using 4-methylcatechol and catechol were 12.57 kJ/mol and 14.23 kJ/mol from respective substrates. Sodium disulfite was a better inhibitor where 79.17% of PPO inhibition was achieved. The isolation and characterization of round brinjal PPO serves as a guideline to predict the behavior of enzyme, leading to effective prevention of its browning during processing and storage.
    Matched MeSH terms: Sulfites
  10. Fulltext Pyrosequencing-based quantitative evaluation of P16 methylation in diffuse large b-cell lymphoma
    Mohd. Ridah L.J., Ismail A., A. Talib N., Muhammad N., Hussain F.A., Zainuddin N.
    Journal of Biomedical and Clinical Sciences, 2016;1(1):12-17.
    MyJurnal
    Introduction: Methylation of promoter region of p16 leading to gene silencing has been implicated ina wide range of malignancies including lymphomas. In diffuse large B cell lymphoma (DLBCL) particularly, a varying percentage of epigenetic inactivation of p16 promoter region was observed ranging from 16 -54%. However, quantitative analysis of p16 promoter methylation in DLBCL has not been extensively studied in Malaysia. Objective: This study aims to quantitatively analyse p16 methylation in DLBCL samples using pyrosequencing technique. Methods: Genomic DNA was extracted from 16 formalin-fixed paraffin-embedded lymphoma tissue blocks from patients diagnosed with DLBCL. Samples were retrieved from Hospital Tengku Ampuan Afzan, Pahang and Hospital Universiti Sains Malaysia, Kelantan. Primers were designed to amplify bisulfite-treated DNA targeting p16 promoter region. Methylation status of 7 CpG sites was determined by pyrosequencing. Results: All the 16 samples studied showed promoter methylation of p16. The range of mean methylation percentage was between 18 to 81%. Conclusion: The present study has successfully measured the level of methylation of p16 in all 7 CpG sites despite the limitation in sample size. Since p16 methylation is a common event in our series of DLBCL cases, it is worth including a larger sample size in future studies to increase the chance of finding a significant correlation with clinical parameters.
    Matched MeSH terms: Sulfites
  11. Nano Fe304-activated carbon composites for aqueous supercapacitors
    Ho M, Khiew P, Isa D, Tan T, Chiu W, Chia C, et al.
    Sains Malaysiana, 2014;43:885-894.
    In this study, a symmetric supercapacitor has been fabricated by adopting the nanostructured iron oxide (Fe304)-activated carbon (Ac) composite as the core electrode materials. The composite electrodes were prepared via a facile mechanical mixing process and PTFE polymeric solution has been used as the electrode material binder. Structural analysis of the nanocomposite electrodes were characterized by scanning electron microscopy ( sEm) and Brunauer-Emmett-Teller (BET) analysis. The electrochemical performances of the prepared supercapacitor were studied using cyclic voltammetry (cv) and electrochemical impedance spectroscopy (Eis) in 1.0 M Na2S03 and 1.0 M Na2SO4 aqueous solutions, respectively. The experimental results showed that the highest specific capacitance of 43 FIg is achieved with a fairly low Fe304 nanomaterials loading (4 wt. %) in 1 M Na2S03. It is clear that the low concentration of nanostructured Fe304 has improved the capacitive performance of the composite via pseudocapacitance charge storage mechanism as well as the enhancement on the specific surface areas of the electrode. However, further increasing of the Fe304 content in the electrode is found to distort the capacitive performance and deteriorate the specific surface area of the electrode, mainly due to the aggregation of the Fe304 particles within the composite. Additionally, the cv results showed that the Fe3041Ac nanocomposite electrode in Na2S03 electrolyte exhibits a better charge storage performance if compared with Na2SO4 solution. It is believed that Fe304 nanoparticles can provide favourable surface adsorption sites for sulphite (S032-) anions which act as catalysts for subsequent redox and intercalation reactions.
    Matched MeSH terms: Sulfites
  12. A new method for FMR1 gene methylation screening by multiplex methylation-specific real-time polymerase chain reaction
    Elias MH, Ankathil R, Salmi AR, Sudhikaran W, Limprasert P, Zilfalil BA
    Genet Test Mol Biomarkers, 2011 Jun;15(6):387-93.
    PMID: 21329465 DOI: 10.1089/gtmb.2010.0191
    Fragile X Syndrome (FXS) is the most common form of inherited mental retardation in men. It is caused by abnormalities in the FMR1 gene that are associated with CGG repeat expansion and the hypermethylation status of its promoter. Methylated alleles lead to transcriptional inhibition and consequent loss of Fragile X Mental Retardation Protein. Chemical modification of cytosine to uracil by bisulfite treatment has proved to be an attractive method for DNA methylation studies that precludes labor-intensive Southern blot analysis, which is the gold standard test for FXS. In this report, bisulfite-treated DNA samples were amplified using real-time multiplex methylation-specific polymerase chain reaction followed by melting curve analysis. Our results show that all control samples with known CGG repeat numbers and methylation statuses were correctly diagnosed. The samples from 43 male patients were also successfully diagnosed, which were in complete agreement with the results of Southern blotting. By such means, 39 patients were found to have an unmethylated allele; 3, a fully mutated allele; and 1, both methylated and unmethylated alleles, thus implying a diagnosis of mosaicism. In conclusion, we find our method to be convenient for screening a large number of male patients with FXS, because it is rapid and easy to perform, especially when there is a low quantity of DNA that must be sensitively and accurately assayed.
    Matched MeSH terms: Sulfites/chemistry
  13. Fulltext Molybdenum cofactor deficiency in a Malaysian child
    Ngu LH, Afroze B, Chen BC, Affandi O, Zabedah MY
    Singapore Med J, 2009 Oct;50(10):e365-7.
    PMID: 19907877
    Molybdenum cofactor deficiency is a rare autosomal recessive disorder with devastating neurological manifestations, characterised by neonatal-onset encephalopathy mimicking hypoxic-ischaemic insult, intractable seizure, and feeding and respiratory difficulties. It is often fatal in the early life. We report an affected 8-year-old boy, who presented with severe neurological manifestations since birth, but without clinically-significant seizure. Molybdenum cofactor deficiency must be included in the differential diagnosis of patients presenting with unexplained encephalopathy in the newborn period, and whose neuroimaging findings are consistent with hypoxic ischaemic encephalopathy. The classic laboratory hallmark of this disorder is low serum uric acid, positive urine sulphite dipstick test, and elevated urinary S-sulphocysteine, hypoxanthine and xanthine.
    Matched MeSH terms: Sulfites/urine
  14. Fulltext Development and evaluation of a new growth medium for Helicobacter pylori
    Sasidharan S, Uyub AM
    FEMS Immunol. Med. Microbiol., 2009 Jun;56(1):94-7.
    PMID: 19309485 DOI: 10.1111/j.1574-695X.2009.00554.x
    The present study was aimed at modifying the original formulation of Commercial Eugon agar (CEA) to develop a new H. pylori growth medium. Initial studies were carried out to determine the number of H. pylori colonies recovered on in-house H. pylori agar (IHPA), IHPA without L-cysteine and sodium sulfite (IHPA-NC), IHPA without L-cysteine (IHPA-C), IHPA without sodium sulfite (IHPA-N) and CEA as the control. Significant differences (P < 0.001) in the number of colonies recovered were observed between IHPA-N, IHPA-NC and IHPA-C. Incorporation of sodium sulfite decreased the number of colonies recovered, indicating that sodium sulfite was inhibitory to H. pylori growth. Removal of L-cysteine reduced the number of colonies recovered, suggesting that L-cysteine is necessary for the growth of H. pylori. In the subsequent study, incorporation of K(2)HPO(4) further increased the number of colonies recovered compared with IHPA-N (P < 0.001), and 0.25% (w/v) of K(2)HPO(4) yielded the highest numbers of colonies (P < or = 0.04). Finally, thirty other H. pylori clinical isolates were evaluated for their growth in the IHPAP-N, a new medium consisting of 1.5% (w/v) pepticase, 0.5% (w/v) peptone, 0.4% (w/v) sodium chloride, 0.03% (w/v) L-cysteine, 0.55% (w/v) dextrose, 0.25% (w/v) K(2)HPO(4) and 1.5% (w/v) agar. The number of colonies recovered in IHPAP-N was significantly (P < 0.005) higher than that of CEA. IHPAP-N with 0.25% K(2)HPO(4) and without sodium sulfite were adequate solid media for the growth of H. pylori.
    Matched MeSH terms: Sulfites
  15. Fulltext Extraction, purification and characterisation of a milk-clotting protease from ‘kesinai’ (Streblus asper Lour.) leaves
    Pagthinathan, M., Ghazali, H.M., Yazid, A.M., Foo, H.L.
    International Food Research Journal, 2019;26(3):913-922.
    MyJurnal
    Extracts from ‘kesinai’ (Streblus asper) leaves were investigated as a potential source of enzymes that can serve as an alternative to calf rennet in cheese making. Different types of extraction buffers were investigated namely sodium acetate buffer (pH 4.2-5.0), phosphate buffer (pH 6.0-7.0) and Tris-HCl buffer (pH 7.0-9.0). Finally, the milk-clotting enzyme was extracted using 100 mM Tris-HCl buffer (pH 7.4) with and without 5.0 mg/mL polyvinylpyrrolidone, 0.015 mL/mL Triton X-100 and 2 mM sodium metabisulphite. Purification was carried out using acetone precipitation, and ion-exchange and size-exclusion chromatographic techniques. Results showed that 100 mM Tris-HCl buffer (pH 7.4) was the most efficient extraction buffer among the buffers used in the extraction study. After the final purification step of size-exclusion chromatography, the enzyme was purified 3.3-fold with 42.3% of recovery. The enzyme showed an optimum temperature and pH at 60°C and pH 7.4, respectively. The enzyme was stable up to 70°C for one hour and the partially purified enzyme retained 83% and 96% of its original activity at pH 6.0 and 8.0, respectively. The molecular weight of the partially enzyme was estimated to be 75.8 kDa on SDS-PAGE. The milk-clotting activity of ‘kesinai’ enzyme was found to be lower than that of commercial Mucor rennet.
    Matched MeSH terms: Sulfites
  16. Fulltext PH-responsive strontium nanoparticles for targeted gene therapy against mammary carcinoma cells
    Bakhtiar A, Chowdhury EH
    Asian J Pharm Sci, 2021 Mar;16(2):236-252.
    PMID: 33995617 DOI: 10.1016/j.ajps.2020.11.002
    Genetic intervention via the delivery of functional genes such as plasmid DNA (pDNA) and short-interfering RNA (siRNA) offers a great way to treat many single or multiple genetic defects effectively, including mammary carcinoma. Delivery of naked therapeutic genes or siRNAs is, however, short-lived due to biological clearance by scavenging nucleases and circulating monocytes. Low cellular internalization of negatively-charged nucleic acids further causes low transfection or silencing activity. Development of safe and effectual gene vectors is therefore undeniably crucial to the success of nucleic acid delivery. Inorganic nanoparticles have attracted considerable attention in the recent years due to their high loading capacity and encapsulation activity. Here we introduce strontium salt-based nanoparticles, namely, strontium sulfate, strontium sulfite and strontium fluoride as new inorganic nanocarriers. Generated strontium salt particles were found to be nanosized with high affinity towards negatively-charged pDNA and siRNA. Degradation of the particles was seen with a drop in pH, suggesting their capacity to respond to pH change and undergo dissolution at endosomal pH to release the genetic materials. While the particles are relatively nontoxic towards the cells, siRNA-loaded SrF2 and SrSO3 particles exerted superior transgene expression and knockdown activity of MAPK and AKT, leading to inhibition of their phosphorylation to a distinctive extent in both MCF-7 and 4T1 cells. Strontium salt nanoparticles have thus emerged as a promising tool for applications in cancer gene therapy.
    Matched MeSH terms: Sulfites
  17. Fulltext Strontium Sulfite: A New pH-Responsive Inorganic Nanocarrier to Deliver Therapeutic siRNAs to Cancer Cells
    Karim ME, Shetty J, Islam RA, Kaiser A, Bakhtiar A, Chowdhury EH
    Pharmaceutics, 2019 Feb 20;11(2).
    PMID: 30791612 DOI: 10.3390/pharmaceutics11020089
    Inorganic nanoparticles hold great potential in the area of precision medicine, particularly for treating cancer owing to their unique physicochemical properties, biocompatibility and improved pharmacokinetics properties compared to their organic counterparts. Here we introduce strontium sulfite nanoparticles as new pH-responsive inorganic nanocarriers for efficient transport of siRNAs into breast cancer cells. We employed the simplest nanoprecipitation method to generate the strontium sulfite nanoparticles (SSNs) and demonstrated the dramatic roles of NaCl and d-glucose in particle growth stabilization in order to produce even smaller nanosize particles (Na-Glc-SSN) with high affinity towards negatively charged siRNA, enabling it to efficiently enter the cancer cells. Moreover, the nanoparticles were found to be degraded with a small drop in pH, suggesting their potential capability to undergo rapid dissolution at endosomal pH so as to release the payload. While these particles were found to be nontoxic to the cells, they showed higher potency in facilitating cancer cell death through intracellular delivery and release of oncogene-specific siRNAs targeting ros1 and egfr1 mRNA transcripts, than the strontium sulfite particles prepared in absence of NaCl and d-glucose, as confirmed by growth inhibition assay. The mouse plasma binding analysis by Q-TOF LC-MS/MS demonstrated less protein binding to smaller particles of Na-Glc-SSNs. The biodistribution studies of the particles after 4 h of treatment showed Na-Glc-SSNs had less off-target distribution than SSNs, and after 24 h, all siRNAs were cleared from all major organs except the tumors. ROS1 siRNA with its potential therapeutic role in treating 4T1-induced breast tumor was selected for subsequent in vivo tumor regression study, revealing that ROS1 siRNA-loaded SSNs exerted more significant anti-tumor effects than Na-Glc-SSNs carrying the same siRNA following intravenous administration, without any systemic toxicity. Thus, strontium sulfite emerged as a powerful siRNA delivery tool with potential applications in cancer gene therapy.
    Matched MeSH terms: Sulfites
  18. p16 Tumor Suppressor Gene Methylation in Diffuse Large B Cell Lymphoma: A Study of 88 Cases at Two Hospitals in the East Coast of Malaysia
    Mohd Ridah LJ, A Talib N, Muhammad N, Hussain FA, Zainuddin N
    Asian Pac J Cancer Prev, 2017 10 26;18(10):2781-2785.
    PMID: 29072413
    Introduction: p16 gene plays an important role in the normal cell cycle regulation. Methylation of p16 has been reported to be one of the epigenetic events contributing to the pathogenesis of diffuse large B-cell lymphoma (DLBCL) which occurring at varying frequency. DLBCL is an aggressive and high-grade malignancy which accounts for approximately 30% of all non-Hodgkin lymphoma cases. However, little is known regarding the epigenetic alterations of p16 gene in DLBCL cases in Malaysia. Therefore, the objective of this study was to examine the status of p16 methylation in DLBCL. Methods: A total of 88 formalin-fixed paraffin-embedded DLBCL tissues retrieved from two hospitals located in the east coast of Malaysia, namely Hospital Tengku Ampuan Afzan (HTAA) Pahang and Hospital Universiti Sains Malaysia (HUSM) Kelantan, were chosen for this study. DNA specimens were isolated and subsequently subjected to bisulfite treatment prior to methylation specific-PCR. Two pairs of primers were used to amplify methylated and unmethylated regions of p16 gene. The PCR products were then separated using agarose gel electrophoresis and visualised under UV illumination. SPSS version 12.0 was utilised to perform all statistical analysis. Result: p16 methylation was detected in 65 of 88 (74%) samples. There was a significant association between p16 methylation status and patients aged >50 years old (p=0.04). Conclusion: Our study demonstrated that methylation of p16 tumor suppressor gene in our DLBCL cases is common and significantly increased among patients aged 50 years and above. Aging is known to be an important risk factor in the development of cancers and we speculate that this might be due to the increased transformation of malignant cells in aging cell population. However, this has yet to be confirmed with further research and correlate the findings with clinicopathological parameters.
    Matched MeSH terms: Sulfites
  19. Fulltext Leucocytic DNA Methylation of Interleukin-6 Promoter Reduction in Pre-Hypertensive Young Adults
    Omar WFNW, Abdullah A, Talib NA, Shah ASM, Rahman JA
    Malays J Med Sci, 2019 Nov;26(6):46-54.
    PMID: 31908586 MyJurnal DOI: 10.21315/mjms2019.26.6.5
    Background: Pre-hypertension is associated with increased risk of cardiovascular disease. Chronic inflammation plays an important role in the pathophysiology of essential hypertension, with epigenetic dysregulation involvement. Nevertheless, the role of DNA methylation in prehypertensive state is unknown. The aim of this study was to investigate the association between DNA methylation level of interleukin-6 (IL-6) promoter in pre-hypertensive (PreHT) and normotensive (NT) young adults.

    Methods: A total of 80 NT and 80 PreHT healthy subjects aged between 18-45 years were recruited in Kuantan, Pahang, Malaysia using an observational cross-sectional study approach. DNA methylation level of IL-6 promoter in peripheral leukocytes were measured using bisulphite conversion and MethyLight assay.

    Results: There was no significant difference in age between NT and PreHT (P = 0.655). The mean blood pressure was 110(8)/73(5) mmHg in NT and 125(7)/82(5) mmHg in PreHT subjects. The IL-6 promoter methylation level was significantly lower in PreHT compared to NT subjects (P < 0.001).

    Conclusion: The current study demonstrates that hypomethylation of IL-6 promoter was associated with pre-hypertension in young adults. Thus, IL-6 methylation could be used as an early indicator for predicting hypertension and related risk of cardiovascular diseases in prehypertensive subjects. Gene expression and longitudinal studies are warranted to examine the methylation effect on IL-6 expression over time.

    Matched MeSH terms: Sulfites
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