Displaying publications 1 - 20 of 278 in total

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  1. Puthucheary SD, Vadivelu J, Ce-Cile C, Kum-Thong W, Ismail G
    Am J Trop Med Hyg, 1996 Mar;54(3):313-4.
    PMID: 8600773
    The occurrence of latency and relapse in human melioidosis suggests adaptations by Burkholderia pseudomallei that help to avoid the human immune response. Ruthenium red-stained preparations of bacterial cultures viewed by electron microscopy revealed three morphologically distinct variants; one with a very marked and another with a less electron-dense layer surrounding the cell wall, and a third variety devoid of such a structure. This structure may be attributable to a layer of polysaccharide, suggesting the presence of a glycocalyx that may aid in the survival of the organism during latency.
    Matched MeSH terms: Polysaccharides/analysis; Polysaccharides/ultrastructure*
  2. Pang T, Levine MM, Ivanoff B, Wain J, Finlay BB
    Trends Microbiol., 1998 Apr;6(4):131-3.
    PMID: 9587187
    Matched MeSH terms: Polysaccharides, Bacterial/immunology
  3. Billa N, Yuen KH, Khader MA, Omar A
    Int J Pharm, 2000 May 15;201(1):109-20.
    PMID: 10867269
    A xanthan gum matrix controlled release tablet formulation containing diclofenac sodium was evaluated in vitro and was found to release the drug at a uniform rate. The gastrointestinal transit behaviour of the formulation as determined by gamma scintigraphy, using healthy male volunteers under fasted and fed conditions, indicated that gastric emptying was delayed with food intake. In contrast, the small intestinal transit remained practically unchanged under both food statuses. Therefore, the delay in caecal arrival observed in the fed state can be attributed to the delay in gastric emptying. Rate of diclofenac sodium absorption was generally higher in the fed state compared to the fasted state, however the total amount absorbed under both food statuses remained practically the same. The rate of in vivo dissolution of the drug in the fed state was faster compared to that in the fasted state. Thus, at the time of caecal arrival, in vivo dissolution was complete in the fed state, unlike in the fasted state, where almost 60% of the drug was delivered to the colon.
    Matched MeSH terms: Polysaccharides, Bacterial
  4. Peh KK, Wong CF
    Drug Dev Ind Pharm, 2000 Jul;26(7):723-30.
    PMID: 10872090
    Controlled-release grade hydroxypropylmethylcellulose (HPMC) or xanthan gum (XG) and microcrystalline cellulose (MCC) were employed to prepare controlled-release diltiazem hydrochloride tablets. The similarity factor f2 was used for dissolution profile comparison using Herbesser 90 SR as a reference product. Drug release could be sustained in a predictable manner by modifying the content of HPMC or XG. Moreover, the drug release profiles of tablets prepared using these matrix materials were not affected by pH and agitation rate. The f2 values showed that only one batch of tablets (of diltiazem HCl, HPMC or XG, and MCC in proportions of 3.0:3.0:4.0) was considered similar to that of the reference product, with values above 50. The unbiased similarity factor f2* values were not much different from the f2 values, ascribing to a small dissolution variance of the test and reference products. The amount of HPMC or XG incorporated to produce tablets with the desired dissolution profile could be determined from the curves of f2 versus polymer content. Hence, the f2 values can be applied as screening and optimization tools during development of controlled-release preparations.
    Matched MeSH terms: Polysaccharides, Bacterial/chemistry
  5. Billa N, Yuen KH
    AAPS PharmSciTech, 2000;1(4):E30.
    PMID: 14727895
    The purpose of this research was to study processing variables at the laboratory and pilot scales that can affect hydration rates of xanthan gum matrices containing diclofenac sodium and the rate of drug release. Tablets from the laboratory scale and pilot scale proceedings were made by wet granulation. Swelling indices of xanthan gum formulations prepared with different amounts of water were measured in water under a magnifying lens. Granules were thermally treated in an oven at 60 degrees C, 70 degrees C, and 80 degrees C to study the effects of elevated temperatures on drug release from xanthan gum matrices. Granules from the pilot scale formulations were bulkier compared to their laboratory scale counterparts, resulting in more porous, softer tablets. Drug release was linear from xanthan gum matrices prepared at the laboratory scale and pilot scales; however, release was faster from the pilot scales. Thermal treatment of the granules did not affect the swelling index and rate of drug release from tablets in both the pilot and laboratory scale proceedings. On the other hand, the release from both proceedings was affected by the amount of water used for granulation and the speed of the impeller during granulation. The data suggest that processing variables that affect the degree of wetness during granulation, such as increase in impeller speed and increase in amount of water used for granulation, also may affect the swelling index of xanthan gum matrices and therefore the rate of drug release.
    Matched MeSH terms: Polysaccharides, Bacterial/metabolism*; Polysaccharides, Bacterial/chemistry
  6. Panchanathan V, Kumar S, Yeap W, Devi S, Ismail R, Sarijan S, et al.
    Bull World Health Organ, 2001;79(9):811-7.
    PMID: 11584728
    To carry out a comparative study of the safety and immunogenicity of Vi polysaccharide vaccine against whole-cell killed (WCK) typhoid vaccine.
    Matched MeSH terms: Polysaccharides, Bacterial/adverse effects; Polysaccharides, Bacterial/immunology*
  7. Kimura Y, Yoshiie T, Kit WK, Maeda M, Kimura M, Tan SH
    Biosci Biotechnol Biochem, 2003 Oct;67(10):2232-9.
    PMID: 14586113
    The pollen of oil palm (Elaeis guineensis Jacq.) is a strong allergen and causes severe pollinosis in Malaysia and Singapore. In the previous study (Biosci. Biotechnol. Biochem., 64, 820-827 (2002)), from the oil palm pollens, we purified an antigenic glycoprotein (Ela g Bd 31 K), which is recognized by IgE from palm pollinosis patients. In this report, we describe the structural analysis of sugar chains linked to palm pollen glycoproteins to confirm the ubiquitous occurrence of antigenic N-glycans in the allergenic pollen. N-Glycans liberated from the pollen glycoprotein mixture by hydrazinolysis were labeled with 2-aminopyridine followed by purification with a combination of size-fractionation HPLC and reversed-phase HPLC. The structures of the PA-sugar chains were analyzed by a combination of two-dimensional sugar chain mapping, electrospray ionization mass spectrometry (ESI-MS), and tandem MS analysis, as well as exoglycosidase digestions. The antigenic N-glycan bearing alpha1-3 fucose and/or beta1-2 xylose residues accounts for 36.9% of total N-glycans: GlcNAc2Man3Xyl1Fuc1GlcNAc2 (24.6%), GlcNAc2Man3Xyl1GlcNAc2 (4.4%), Man3Xyl1Fuc1-GlcNAc2 (1.1%), GlcNAc1Man3Xyl1Fuc1GlcNAc2 (5.6%), and GlcNAc1Man3Xyl1GlcNAc2 (1.2%). The remaining 63.1% of the total N-glycans belong to the high-mannose type structure: Man9GlcNAc2 (5.8%), Man8GlcNAc2 (32.1%), Man7GlcNAc2 (19.9%), Man6GlcNAc2 (5.3%).
    Matched MeSH terms: Polysaccharides/immunology; Polysaccharides/chemistry*
  8. Tang SS, Tan WS, Devi S, Wang LF, Pang T, Thong KL
    Clin Diagn Lab Immunol, 2003 Nov;10(6):1078-84.
    PMID: 14607870
    The capsular polysaccharide Vi antigen (ViCPS) is an essential virulence factor and also a protective antigen of Salmonella enterica serovar Typhi. A random 12-mer phage-displayed peptide library was used to identify mimotopes (epitope analogues) of this antigen by panning against a ViCPS-specific monoclonal antibody (MAb) ATVi. Approximately 75% of the phage clones selected in the fourth round carried the peptide sequence TSHHDSHGLHRV, and the rest of the clones harbored ENHSPVNIAHKL and other related sequences. These two sequences were also obtained in a similar panning process by using pooled sera from patients with a confirmed diagnosis of typhoid fever, suggesting they mimic immunodominant epitopes of ViCPS antigens. Binding of MAb ATVi to the mimotopes was specifically blocked by ViCPS, indicating that they interact with the same binding site (paratope) of the MAb. Data and reagents generated in this study have important implications for the development of peptide-base diagnostic tests and peptide vaccines and may also provide a better understanding of the pathogenesis of typhoid fever.
    Matched MeSH terms: Polysaccharides, Bacterial/immunology*
  9. Lazan H, Ng SY, Goh LY, Ali ZM
    Plant Physiol Biochem, 2004 Dec;42(11):847-53.
    PMID: 15694277
    The potential significance of the previously reported papaya (Carica papaya L.) beta-galactosidase/galactanase (beta-d-galactoside galactohydrolase; EC 3.2.1.23) isoforms, beta-gal I, II and III, as softening enzymes during ripening was evaluated for hydrolysis of pectins while still structurally attached to unripe fruit cell wall, and hemicelluloses that were already solubilized in 4 M alkali. The enzymes were capable of differentially hydrolyzing the cell wall as evidenced by increased pectin solubility, pectin depolymerization, and degradation of the alkali-soluble hemicelluloses (ASH). This enzyme catalyzed in vitro changes to the cell walls reflecting in part the changes that occur in situ during ripening. beta-Galactosidase II was most effective in hydrolyzing pectin, followed by beta-gal III and I. The reverse appeared to be true with respect to the hemicelluloses. Hemicellulose, which was already released from any architectural constraints, seemed to be hydrolyzed more extensively than the pectins. The ability of the beta-galactanases to markedly hydrolyze pectin and hemicellulose suggests that galactans provide a structural cross-linkage between the cell wall components. Collectively, the results support the case for a functional relevance of the papaya enzymes in softening related changes during ripening.
    Matched MeSH terms: Polysaccharides/metabolism*
  10. Balasubramaniam S, Lee HC, Lazan H, Othman R, Ali ZM
    Phytochemistry, 2005 Jan;66(2):153-63.
    PMID: 15652572
    beta-Galactosidase (EC. 3.2.1.23) from ripe carambola (Averrhoa carambola L. cv. B10) fruit was fractionated through a combination of ion exchange and gel filtration chromatography into four isoforms, viz. beta-galactosidase I, II, III and IV. This beta-galactosidases had apparent native molecular masses of 84, 77, 58 and 130 kDa, respectively. beta-Galactosidase I, the predominant isoform, was purified to electrophoretic homogeneity; analysis of the protein by SDS-PAGE revealed two subunits with molecular masses of 48 and 36 kDa. N-terminal amino acid sequence of the respective polypeptides shared high similarities albeit at different domains, with the deduced amino acid sequence of certain plant beta-galactosidases, thus, explaining the observed low similarity between the two subunits. beta-Galactosidase I was probably a heterodimer that have glycoprotein properties and a pI value of 7.2, with one of the potential glycosylation sites appeared to reside within the 48-kDa-polypeptide. The purified beta-galactosidase I was substantially active in hydrolyzing (1-->4)beta-linked spruce and a mixture of (1-->3)beta- and (1-->6)beta-linked gum arabic galactans. This isoform also had the capability to solubilize and depolymerize structurally intact pectins as well as to modify alkaline-soluble hemicelluloses, reflecting in part changes that occur during ripening.
    Matched MeSH terms: Polysaccharides/metabolism*; Polysaccharides/chemistry
  11. Sunderasan E, Bahari A, Arif SA, Zainal Z, Hamilton RG, Yeang HY
    Clin Exp Allergy, 2005 Nov;35(11):1490-5.
    PMID: 16297147 DOI: 10.1111/j.1365-2222.2005.02371.x
    BACKGROUND:
    Hev b 4 is an allergenic natural rubber latex (NRL) protein complex that is reactive in skin prick tests and in vitro immunoassays. On SDS-polyacrylamide gel electrophoresis (SDS-PAGE), Hev b 4 is discerned predominantly at 53-55 kDa together with a 57 kDa minor component previously identified as a cyanogenic glucosidase. Of the 13 NRL allergens recognized by the International Union of Immunological Societies, the 53-55 kDa Hev b 4 major protein is the only candidate that lacks complete cDNA and protein sequence information.

    OBJECTIVE:
    We sought to clone the transcript encoding the Hev b 4 major protein, and characterize the native protein and its recombinant form in relation to IgE binding.

    METHODS:
    The 5'/3' rapid amplification of cDNA ends method was employed to obtain the complete cDNA of the Hev b 4 major protein. A recombinant form of the protein was over-expressed in Escherichia coli. The native Hev b 4 major protein was deglycosylated by trifluoromethane sulphonic acid. Western immunoblots of the native, deglycosylated and recombinant proteins were performed using both polyclonal antibodies and sera from latex-allergic patients.

    RESULTS:
    The cDNA encoding the Hev b 4 major protein was cloned. Its open reading frame matched lecithinases in the conserved domain database and contained 10 predicted glycosylation sites. Detection of glycans on the Hev b 4 lecithinase homologue confirmed it to be a glycoprotein. The deglycosylated lecithinase homologue was discerned at 40 kDa on SDS-PAGE, this being comparable to the 38.53 kDa mass predicted by its cDNA. Deglycosylation of the lecithinase homologue resulted in the loss of IgE recognition, although reactivity to polyclonal rabbit anti-Hev b 4 was retained. IgE from latex-allergic patients also failed to recognize the non-glycosylated E. coli recombinant lecithinase homologue.

    CONCLUSION:
    The IgE epitopes of the Hev b 4 lecithinase homologue reside mainly in its carbohydrate moiety, which also account for the discrepancy between the observed molecular weight of the protein and the value calculated from its cDNA.
    Matched MeSH terms: Polysaccharides/immunology
  12. Iluyemi FB, Hanafi MM, Radziah O, Kamarudin MS
    Bioresour Technol, 2006 Feb;97(3):477-82.
    PMID: 16216731
    Palm kernel cake (PKC), an agro-industrial by-product used extensively in the animal feed industry, has limited use in fish feeds due to its high fiber and low protein contents. In this study, PKC was processed under solid state culture conditions with five fungal strains and the effect of this fungal culturing on the amino acid, fatty acid, cellulose and hemicellulose fractions was evaluated. Fungal strains used were Sclerotium rolfsii, Trichoderma harzianum, Trichoderma longiobrachiatum, Trichoderma koninggi and Aspergillus niger. Fungal growth was carried out at 50% moisture level and 1% inoculum level for 7 days. A significant increase in protein content from 18.76% to 32.79% was obtained by growing T. longibrachiatum on PKC. Cellulose level decreased significantly from 28.31% to 12.11% for PKC cultured with T. longibrachiatum, and hemicellulose from 37.03% to 19.01% for PKC cultured with A. niger. Fungal culturing of PKC brought about an increase in the level of unsaturated- and a decrease in the level of the saturated-fatty acids.
    Matched MeSH terms: Polysaccharides/analysis
  13. Thong KL, Tang SS, Tan WS, Devi S
    Microbiol. Immunol., 2007;51(11):1045-52.
    PMID: 18037781
    Polyclonal sera from typhoid patients and a monoclonal antibody, mAb ATVi, which recognizes the capsular polysaccharide Vi antigen (ViCPS), were used to select for peptides that mimic the ViCPS by using a phage-displayed random 12-mer peptide library. Two major common mimotopes selected from the library carried the amino acid sequences TSHHDSHGLHRV and ENHSPVNIAHKL. Enzyme-linked immunosorbent assays (ELISAs) showed that these peptides carry mimotopes to ViCPS. Phage clones that contained the 12-mer peptides were also tested against pooled/individual typhoid patients' sera and found to have 3 to 5 times higher binding compared to normal sera. By using Phage-ELISA assays, the derived synthetic peptides, TSHHDSHGLHRV and ENHSPVNIAHKL, were tested against a monoclonal antibody mAb ATVi and over 2-fold difference in binding was found between these peptides and a control unrelated peptide, CTLTTKLYC. Inhibition of the mAb's binding to ViCPS indicated that the synthetic peptides successfully competed with the capsular polysaccharide for antibody binding.
    Matched MeSH terms: Polysaccharides, Bacterial/immunology*
  14. Sahalan AZ, Dixon RA
    Int J Antimicrob Agents, 2008 Mar;31(3):224-7.
    PMID: 18083010
    The role of membrane permeabilisation and disruption in the mechanism of action of some polymyxin analogues against Gram-negative organisms is contentious. The effects of polymyxin B (PMB) and its analogue polymyxin B nonapeptide (PMBN) on Escherichia coli envelopes should correlate, but previous work by other workers suggests that PMBN has a different mode of action. This study has reassessed the biochemical techniques used previously and has shown that, in contrast to previous studies, PMBN (a well-characterised antibacterial synergist) readily releases periplasmic proteins and lipopolysaccharide from treated E. coli at subinhibitory concentrations in normal physiological buffer conditions. We conclude that, when tested with appropriate methodology, PMBN closely correlates with the early effects of PMB on the cell envelope of E. coli and this study shows that it is now consistent with the accepted interactions of membrane-active agents against Gram-negative cells.
    Matched MeSH terms: Polysaccharides, Bacterial/metabolism
  15. Kuan YH, Liong MT
    J Agric Food Chem, 2008 Oct 8;56(19):9252-7.
    PMID: 18788708 DOI: 10.1021/jf802011j
    The objective of this study was to evaluate the chemical, physicochemical, and functional properties of agrowastes derived from okara ( Glycine max), corn cob ( Zea mays sp.), wheat straw ( Triticum sp.), and rice husk ( Oryza sativa) for potential applications in foods. The fibrous materials (FM) were treated with alkali to yield fibrous residues (FR). Rice husk contained the highest ash content (FM, 8.56%; FR, 9.04%) and lowest lightness in color (FM, 67.63; FR, 63.46), possibly due to the abundance of mineral constituents. Corn cob contained the highest amount of soluble dietary fiber (SDF), whereas okara had the highest total dietary fiber (TDF). The high dietary fiber fractions of corn cob and okara also contributed to the highest water- and oil-holding capacities, emulsifying activities, and emulsion stabilities for both FM and FR samples. These results indicate that these agrowastes could be utilized as functional ingredients in foods.
    Matched MeSH terms: Polysaccharides/chemistry
  16. Shuhaimi M, Kabeir BM, Yazid AM, Nazrul Somchit M
    J Appl Microbiol, 2009 Jan;106(1):191-8.
    PMID: 19054238 DOI: 10.1111/j.1365-2672.2008.03991.x
    This study demonstrated the optimum growth of Bifidobacterium pseudocatenulatum G4 with prebiotics via statistical model.
    Matched MeSH terms: Polysaccharides/metabolism
  17. Fazilah A, Azemi MN, Karim AA, Norakma MN
    J Agric Food Chem, 2009 Feb 25;57(4):1527-31.
    PMID: 19166335 DOI: 10.1021/jf8028013
    Hemicelluloses from oil palm frond (OPF) were extracted using 3 M potassium hydroxide (KOH) for 4 h at 40 degrees C with stirring at 400 rpm to obtain hemicelluloses A and B. The total yield of the hemicellulose isolated from OPF was 33% (dry weight). Both hemicelluloses A and B were then subjected to hydrothermal treatment at 121 degrees C and 1.03 x 10(5) Pa for 10, 30, and 50 min. Physicochemical characterizations of hydrothermally treated hemicelluloses, such as Klason lignin content and reducing sugar content, were performed to study the effect of autohydrolysis processing on OPF-derived hemicelluloses. It was shown that Klason lignin content in hemicellulose A was higher than that in hemicellulose B and decreased after hydrothermal treatment. Hydrothermal treatment enhanced the solubility of hemicelluloses, which reflects their higher reducing sugar content. Monosaccharide analysis using HPLC showed that xylose was the predominant monosaccharide for both hemicelluloses A and B.
    Matched MeSH terms: Polysaccharides/analysis; Polysaccharides/isolation & purification; Polysaccharides/chemistry*
  18. Lim BK, Thong KL
    J Infect Dev Ctries, 2009 Jul 01;3(6):420-8.
    PMID: 19762954
    BACKGROUND: Differentiation of Salmonella enterica into its serogroups is important for epidemiological study. The objective of the study was to apply a multiplex PCR targeting serogroups A, B, C1, D, E and Vi-positive strains of Salmonella enterica commonly found in Malaysia. A separate H-typing multiplex PCR which identified flagellar antigen "a", "b" or "d" was also optimized to confirm clinical serotypes, S. Paratyphi A and S. Typhi.

    METHODOLOGY: Sixty-seven laboratory Salmonella enterica strains were tested. Six sets of primers targeting defined regions of the O antigen synthesis genes (rfb gene cluster) and Vi antigen gene (viaB) were selected and combined into a multiplex PCR for O-grouping. Four primers (H-for, Ha-rev, Hb-rev and Hd-rev) were used in the second step multiplex PCR for H-typing. The optimized mPCR assays were further evaluated with 58 blind-coded Salmonella strains.

    RESULTS: The multiplex PCR results obtained showed 100% concordance to the conventionally typed serogroups. Validation with 58 blind coded Salmonella strains yield 100% accuracy and specificity.

    CONCLUSION: Based on this study, PCR serogrouping proved to be a rapid, alternative method for further differentiation of Salmonella enterica.

    Matched MeSH terms: Polysaccharides, Bacterial/genetics
  19. Rajinikanth PS, Mishra B
    Chem Pharm Bull (Tokyo), 2009 Oct;57(10):1068-75.
    PMID: 19801860
    Gellan gum based floating beads containing clarithromycin (FBC) were prepared by iontotropic gelation method for stomach-specific drug delivery against Helicobacter pylori. The scanning electron microscope photograph indicated that prepared beads were spherical in shape with rough outer surface. Formulation variables such as concentrations of gellan, calcium carbonate and drug loading influenced the in vitro drug release characteristics of prepared beads. In vitro release rate of clarithromycin was corrected using first order degradation rate constant which is degraded significantly during the release study in simulated gastric fluid pH 2.0. Further, the absence of interactions between drug and polymer was confirmed by differential scanning calorimetry analysis. Kinetic treatment of the in vitro drug release data with different kinetic equations revealed matrix diffusion mechanism. Prepared beads showed good anti-microbial activity against isolated H. pylori strain. The prepared beads have shown good in vivo floating efficiency in rabbit stomach. The stability studies of beads did not show any significant changes after storage of beads at 40 degrees C/75% relative humidity for 6 months. The preliminary results from this study suggest that floating beads of gellan can be used to incorporate antibiotics like clarithromycin and may be effective when administered locally in the stomach against H. pylori.
    Matched MeSH terms: Polysaccharides, Bacterial/pharmacology; Polysaccharides, Bacterial/chemistry
  20. Muskhazli Mustafa, Nor Azwady Abd. Aziz, Anida Kaimi, Nurul Shafiza Noor, Salifah Hasanah Ahmad Bedawi, Nalisha Ithnin
    MyJurnal
    The β-1,6-glucanases are ubiquitous enzymes which appear to be implicated in the morphogenesis and have the ability to become virulence factor in plant-fungal symbiotic interaction. To our knowledge, no report on ß-1,6-glucanases purification from Trichoderma longibrachiatum has been made, although it has been proven to have a significant effect as a biocontrol agent for several diseases. Therefore, the aim of this study was to purify β-1,6- glucanase from T. longibrachiatum T28, with an assessment on the physicochemical properties and substrate specificity. β-1,3-glucanase enzyme, from the culture filtrate of T. longibrachiatum T28, was successively purified through precipitation with 80% acetone, followed by anionexchange chromatography on Neobar AQ and chromatofocusing on a Mono P HR 5/20 column. (One β-1,6-glucanase) band at 42kDa in size was purified, as shown by the SDS-PAGE. The physicochemical evaluation showed an optimum pH of 5 and optimum temperature of 50°C for enzyme activity with an ability to maintain 100% enzyme stability. Enzyme activity was slightly reduced by 10-20% in the presence of 20 mM of Zn2+, Ca2+, Co2+, Mg2+, Cu2+, Mn2+ and Fe2+. The highest β-1,6-glucanase hydrolysis activity was obtained on pustulan due to the similarity of β-glucosidic bonds followed by laminarin, glucan and cellulose. Therefore, it can be concluded that the characterization of ß-1,6-glucanase secreted by T. longibrachiatum in term of molecular weight, responsed to selected physicochemical factors and the substrate specificity are approximately identical to other Trichoderma sp.
    Matched MeSH terms: Polysaccharides
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