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Glucan
Kinds of Glucan Terms modified by Glucan Selected AbstractsAssociation of immunological disorders in lethal side effect of NSAIDs on ,-glucan-administered miceFEMS IMMUNOLOGY & MEDICAL MICROBIOLOGY, Issue 1 2001Hideaki Takahashi Abstract (1,3)-,- d -Glucan (,-glucan) is a biological response modifier that regulates host immune response. We have found that the combination of a ,-glucan and a non-steroidal anti-inflammatory drug (NSAID), indomethacin (IND), induced lethal toxicity in mice [Yoshioka et al. (1998) FEMS Immunol. Med. Microbiol., 21, 171,179]. This study was undertaken to analyze the mechanism of the lethal side effect. Combination of a ,-glucan and IND increased the number of leukocytes, especially macrophages and neutrophils, in various organs and these cells were activated. The activated state of these cells was supported by the enhanced production of interferon-, in the presence of IND in vitro culture of the peritoneal exudate cells. Intestinal bacterial flora was translocated into the peritoneal cavity in these mice to cause peritonitis. Comparing the toxicity of various NSAIDs, nabumetone, a partially cyclooxygenase-2-selective NSAID with weaker toxicity to the gastrointestinal tract, did not exhibit a lethal side effect. These facts strongly suggested that gastrointestinal damage by NSAIDs was more severe in ,-glucan-administered mice, resulting in peritonitis by enteric bacteria and leading to death. [source] In vitro fermentation of cereal dietary fibre carbohydrates by probiotic and intestinal bacteriaJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 8 2002Ross Crittenden Abstract A range of probiotic and other intestinal bacteria were examined for their ability to ferment the dietary fibre carbohydrates ,-glucan, xylan, xylo-oligosaccharides (XOS) and arabinoxylan. ,-Glucan was fermented by Bacteroides spp and Clostridium beijerinckii but was not fermented by lactobacilli, bifidobacteria, enterococci or Escherichia coli. Unsubstituted xylan was not fermented by any of the probiotic bacteria examined. However, many Bifidobacterium species and Lactobacillus brevis were able to grow to high yields using XOS. XOS were also efficiently fermented by some Bacteroides isolates but not by E coli, enterococci, Clostridium difficile, Clostridium perfringens or by the majority of intestinal Lactobacillus species examined. Bifidobacterium longum strains were able to grow well using arabinoxylan as the sole carbon source. These organisms hydrolysed and fermented the arabinosyl residues from arabinoxylan but did not substantially utilise the xylan backbone of the polysaccharide. Arabinoxylan was not fermented by lactobacilli, enterococci, E coli, C perfringens or C difficile and has potential to be an applicable carbohydrate to complement probiotic Bif longum strains in synbiotic combinations. © 2002 Society of Chemical Industry [source] Immunological Response to (1,4)-,- d -Glucan in the Lung and Spleen of Endotoxin-Stimulated Juvenile RatsBASIC AND CLINICAL PHARMACOLOGY & TOXICOLOGY, Issue 5 2009Ectis A. Velazquez Experimental groups (n = 16/group) included controls with an intraperitoneal injection of saline, endotoxaemic rats with a non-lethal dose of 10 mg/kg Escherichia coli endotoxin, and endotoxaemic rats treated with two doses of 10 mg/kg ,-DG, intraperitoneally, 2 and 4 hr after endotoxin injection. At 24 hr of treatment, rats were euthanized and lungs and spleen were removed for cytokines determination and lung injury. Endotoxaemia increased IL-1, concentration by fivefold in both organs, while creating a moderate pulmonary hypercellularity (demonstrated by about 11% increase in the alveolar-septal thickening and 11% decrease in the alveolar-interstitial space ratio). In the lung, ,-DG treatment reduced concentrations of IL-1, by 30% (p > 0.05), IL-6 by 43% (p < 0.01), IFN-, by 46% (p < 0.01) and the anti-inflammatory cytokine, IL-10, by 31% (p > 0.05) compared to endotoxaemia. In the spleen, ,-DG treatment decreased the ratio of IL-1, to IL-10 by 55% (p < 0.05), demonstrating an anti-inflammatory trend. These data suggest that ,-DG differentially modulates cytokine response in the lung and spleen and modifies the pro- and anti-inflammatory balance during an early period of endotoxaemia in juvenile rats. [source] Physiological Effects of a Novel Immune Stimulator Drug, (1,4)-,- d -Glucan, in RatsBASIC AND CLINICAL PHARMACOLOGY & TOXICOLOGY, Issue 4 2009Ravishankar Koppada We investigated physiological and immunological effects of a low and a high dose of ,- d -glucan (0.5 and 10 mg/kg), in vivo, testing the hypothesis that intravenous administration of ,- d -glucan does not affect haemodynamic, respiratory, haematological, and immune responses in normal rats. Male rats (300,400 g) were anaesthetized, tracheostomized, and catheterized in one femoral artery and vein. The mean arterial blood pressure and heart rate were continuously recorded. The baselines for gas exchange, differential blood cell count, and plasma concentration of TNF-,, IL-1,, IL-4, IL-6, and IFN-, were determined. Rats were then randomly assigned to controls (n = 7), a low dose (0.5 mg/kg; n = 10), and a high dose (10 mg/kg; n = 7) of ,- d -glucan for a six 6 hr study period. Gas exchange, differential cell count, plasma concentration of TNF-,, IL-1,, IL-4, IL-6, and IFN-,, and mean arterial blood pressure values remained within physiological range. Intravenous administration of 10 mg/kg ,- d -glucan created tachycardia, associated with hyperventilation, and significant reductions in the blood haemoglobin and haematocrit concentrations. We suggest that these in vivo effects of ,- d -glucan should be considered for future clinical and/or experimental trials. [source] Requirement of phospholipase C-,2 (PLC,2) for Dectin-1-induced antigen presentation and induction of TH1/TH17 polarizationEUROPEAN JOURNAL OF IMMUNOLOGY, Issue 5 2009Ilaria Tassi Abstract DC recognize microbial components through an array of receptors known as PRR. PRR initiate intracellular signals, which engender DC with the capacity to stimulate T-cell responses. Dectin-1 is a PRR that recognizes ,-glucan, a major constituent of many fungi's outer cell wall. Here we show that Dectin-1 activates DC through phospholipase (PLC),2 signaling. PLC,2-deficient DC were unable to expand antigen-specific T cells and induce TH1 and TH17 differentiation in response to ,-glucan. Mechanistically, PLC,2-deficiency impaired the capacity of DC to secrete polarizing cytokines following exposure to ,-glucan. Dectin-1 required PLC,2 to activate MAPK, AP-1 and NF-,B, which induce cytokine gene expression. Moreover, PLC,2 controlled Dectin-1-mediated NFAT activation and induction of NFAT-dependent genes such as IL-2, cyclooxigenase-2 and Egr transcription factors. We conclude that PLC,2 is a crucial signaling mediator that modifies DC gene expression program to activate DC responses to ,-glucan-containing pathogens. [source] Cross-linking tumor cells with effector cells via CD55 with a bispecific mAb induces ,-glucan-dependent CR3-dependent cellular cytotoxicityEUROPEAN JOURNAL OF IMMUNOLOGY, Issue 4 2006Abstract Complement (C) regulatory proteins decrease the effectiveness of immunotherapeutic anti-cancer antibodies. Bispecific mAb (bi-mAb) that target a tumor antigen and simultaneously inhibit a C regulator increase the effectiveness of such a therapy. Here we investigated the mechanism by which bi-mAb increase tumor cell lysis. Apart from C-dependent cytotoxicity, C activation can lead to complement receptor 3 (CR3)-dependent cellular cytotoxicity (CR3-DCC) by CR3-positive effector cells in the presence of ,-glucan. Here we show that an anti-Ep-CAM*anti-CD55 bi-mAb induced more than threefold higher CR3-DCC (71%) of human colorectal cancer cells compared with anti-Ep-CAM alone (20%). This CR3-DCC was dependent on the binding of the anti-CD55 arm of tumor-bound anti-Ep-CAM*anti-CD55 bi-mAb to effector cell CD55, CR3 priming by ,-glucan and the presence of iC3b on the target cell. Comparable lysis could be obtained in the absence of iC3b, when CR3 and CD55 were cross-linked on the effector cells, suggesting cooperation between CD55 and CR3 in signal transduction. Tumor cells with low antigen expression were effectively lysed via this mechanism in contrast to direct C-dependent cytotoxicity. These data imply that the effectiveness of mAb immunotherapy can be improved using anti-tumor antigen*anti-CD55 bi-mAb and ,-glucan, thereby initiating CR3-DCC as an additional effector mechanism that is efficient for eradication of tumor cells with lower antigen expression. [source] Involvement of Gln937 of Streptococcus downei GTF-I glucansucrase in transition-state stabilizationFEBS JOURNAL, Issue 13 2000Vincent Monchois Multiple alignment of deduced amino-acid sequences of glucansucrases (glucosyltransferases and dextransucrases) from oral streptococci and Leuconostoc mesenteroides has shown them to share a well-conserved catalytic domain. A portion of this domain displays homology to members of the ,-amylase family (glycoside hydrolase family 13), which all have a (,/,)8 barrel structure. In the glucansucrases, however, the ,-helix and ,-strand elements are circularly permuted with respect to the order in family 13. Previous work has shown that amino-acid residues contributing to the active site of glucansucrases are situated in structural elements that align with those of family 13. In ,-amylase and cyclodextrin glucanotransferase, a histidine residue has been identified that acts to stabilize the transition state, and a histidine is conserved at the corresponding position in all other members of family 13. In all the glucansucrases, however, the aligned position is occupied by glutamine. Mutants of glucosyltransferase I were constructed in which this glutamine, Gln937, was changed to histidine, glutamic acid, aspartic acid, asparagine or alanine. The effects on specific activity, ability to form glucan and ability to transfer glucose to a maltose acceptor were examined. Only histidine could substitute for glutamine and maintain Michaelis,Menten kinetics, albeit at a greatly reduced kcat, showing that Gln937 plays a functionally equivalent role to the histidine in family 13. This provides additional evidence in support of the proposed alignment of the (,/,)8 barrel structures. Mutation at position 937 altered the acceptor reaction with maltose, and resulted in the synthesis of novel gluco-oligosaccharides in which ,1,3-linked glucosyl units are joined sequentially to maltose. [source] Role of anti-,-glucan antibody in host defense against fungiFEMS IMMUNOLOGY & MEDICAL MICROBIOLOGY, Issue 1 2005Ken-ichi Ishibashi Abstract We have recently detected an anti-,-glucan antibody in normal human and normal mouse sera. The anti-,-glucan antibody showed reactivity to pathogenic fungal Aspergillus and Candida cell wall glucan. Anti-,-glucan antibody could bind whole Candida cells. It also enhanced the candidacidal activity of macrophages in vitro. The anti-,-glucan antibody titer of DBA/2 mice intravenously administered either Candida or Aspergillus solubilized cell wall ,-glucan decreased remarkably dependent on dose. Moreover, in deep mycosis patients, the anti-,-glucan antibody titer decreased, and this change correlated with clinical symptoms and other parameters such as C-reactive protein. It was suggested that the anti-,-glucan antibody formed an antigen,antibody complex and participated in the immune response as a molecule recognizing pathogenic fungi. [source] Association of immunological disorders in lethal side effect of NSAIDs on ,-glucan-administered miceFEMS IMMUNOLOGY & MEDICAL MICROBIOLOGY, Issue 1 2001Hideaki Takahashi Abstract (1,3)-,- d -Glucan (,-glucan) is a biological response modifier that regulates host immune response. We have found that the combination of a ,-glucan and a non-steroidal anti-inflammatory drug (NSAID), indomethacin (IND), induced lethal toxicity in mice [Yoshioka et al. (1998) FEMS Immunol. Med. Microbiol., 21, 171,179]. This study was undertaken to analyze the mechanism of the lethal side effect. Combination of a ,-glucan and IND increased the number of leukocytes, especially macrophages and neutrophils, in various organs and these cells were activated. The activated state of these cells was supported by the enhanced production of interferon-, in the presence of IND in vitro culture of the peritoneal exudate cells. Intestinal bacterial flora was translocated into the peritoneal cavity in these mice to cause peritonitis. Comparing the toxicity of various NSAIDs, nabumetone, a partially cyclooxygenase-2-selective NSAID with weaker toxicity to the gastrointestinal tract, did not exhibit a lethal side effect. These facts strongly suggested that gastrointestinal damage by NSAIDs was more severe in ,-glucan-administered mice, resulting in peritonitis by enteric bacteria and leading to death. [source] Measurement of blood clearance time by Limulus G test of Candida -water soluble polysaccharide fraction, CAWS, in miceFEMS IMMUNOLOGY & MEDICAL MICROBIOLOGY, Issue 1 2000Kiyoshi Kurihara Abstract The Limulus G test, responsive to ,-1,3- d -glucan, is a well-established method for the detection of invasive fungal infection. We have recently found that Candida albicans released a water-soluble polysaccharide fraction (CAWS) into synthetic medium (Uchiyama et al., FEMS Immunol. Med. Microbiol. 24 (1999) 411,420). CAWS was composed of a mannoprotein-,-glucan complex and activated Limulus factor G, and thus would be similar to the Limulus active substance in patient's blood. In a preliminary investigation, we have found that CAWS is lethal when administered intravenously in a murine system. In this study, we examined the toxicity and then the fate of CAWS in mice. The lethal toxicity was strain-dependent and strain DBA/2 was the most resistant. The toxicity was, at least in part, reduced by salbutamol sulfate and prednisolone treatment in the sensitive strains. On intravenous administration, the half clearance time (t1/2) was approximately 40 min in mice (DBA/2). On intraperitoneal administration, CAWS appeared in the blood with a peak concentration at 1 h. In order to establish a treatment plan, it is important to demonstrate the onset and the termination of deep-seated mycosis. The Limulus G test is suitable for the above purpose; however, it is necessary to fully understand the fate of ,-1,3- d -glucan in patients' blood [source] Meu10 is required for spore wall maturation in Schizosaccharomyces pombeGENES TO CELLS, Issue 2 2002Takahiro Tougan Background: Many genes are meiosis and/or sporulation-specifically transcribed during this process. Isolation and analysis of these genes might help us to understand how meiosis and sporulation are regulated. For this purpose, we have isolated a large number of cDNA clones from Schizosaccharomyces pombe whose expression is up-regulated during meiosis. Results: We have isolated meu10+ gene, which encodes 416 amino acids and bears homology to SPS2 of Saccharomyces cerevisiae. A strain whose meu10+ gene has been deleted forms no viable spores. Thin-section electron micrographs showed that the meu10, strain has abnormally formed spore walls, and then they disrupt, allowing cytoplasmic material to escape. The Meu10-GFP fusion protein is localized to the spore periphery, thereafter returned to the cytoplasm after sporulation. Meu10-GFP localization to the spore wall was almost normal in the bgs2, or chs1, mutants that lack 1,3-,-glucan or chitin, respectively. In contrast, 1,3-,-glucan is abnormally localized in meu10, cells. Meu10 has an N-terminal domain with homology to the mammalian insulin receptor and a C-terminal domain with a transmembrane motif. Mutants whose N-terminal or C-terminal domain was truncated were severely defective for sporulation. Conclusions: Meu10 is a spore wall component and plays a pivotal role in the formation of the mature spore wall structure. [source] Movement of yeast 1,3-,-glucan synthase is essential for uniform cell wall synthesisGENES TO CELLS, Issue 1 2002Takahiko Utsugi Background:, The cell wall has an important role in maintaining cell shape. In the budding yeast Saccharomyces cerevisiae, the major filamentous component of the cell wall responsible for its rigidity is 1,3-,-glucan and is synthesized by 1,3-,-glucan synthase (GS), localized on the plasma membrane. Results:, Observations of green fluorescent protein (GFP)-conjugated Fks1p, a catalytic subunit of GS, revealed that it is co-localized with cortical actin patches and moves on the cell surface at the sites of cell wall remodelling. Mutants with impaired actin patch movement show immobility of Fks1p-GFP spots, indicating that actin patch motility is required for the movement of Fks1p. Cells with immobilized Fks1p exhibit defective cell wall structure and function. The cell wall thickness of the mutants becomes irregular, eventually leading to cell lysis. Conclusion:, We propose that GS movement is necessary for proper cell wall remodelling. [source] Receptor-mediated phagocytosis of rat macrophages is regulated differentially for opsonized particles and non-opsonized particles containing ,-glucanIMMUNOLOGY, Issue 2 2001Jonathan S. Reichner Summary Experiments were conducted to test the hypothesis that opsonic and non-opsonic phagocytic capacities are differentially regulated by resting and wound-derived macrophages. Furthermore, the phagocytosis of non-opsonized zymosan and ,-glucan particles was quantified to determine whether cells differentially regulate non-opsonic lectinophagocytosis in accordance with the carbohydrate composition of the ligand. In that regard, wound macrophages exhibited profound differential regulation in lectinophagocytosis with a seven-fold increase in phagocytosis of ,-glucan particles following overnight culture but with a relatively modest increase in internalization of mannan-containing zymosan. Cultured peritoneal macrophages increased uptake of both particles similarly. Upon activation with interferon-,/lipopolysaccharide (IFN-,/LPS), wound macrophages selectively suppressed ,-glucan ingestion, while phagocytosis of zymosan particles was unaffected. Lectinophagocytosis was decreased in activated peritoneal macrophages regardless of particle composition and was due in part to a nitric oxide-dependent mechanism which was without a role in regulation of wound macrophage lectinophagocytosis. Overnight culture of wound macrophages suppressed their capacity for opsonic-dependent phagocytosis independently of activation, whereas suppression of phagocytosis by peritoneal macrophages was activation-dependent. Regulation of all three phagocytic pathways was achieved distinctly by peritoneal and wound-derived macrophages, with changes found in the percentage of resident peritoneal macrophages capable of phagocytosis, whereas the phagocytic capacity of wound macrophages was primarily affected by the number of particles ingested by individual cells. Taken together, these findings demonstrate that the differential regulation of phagocytic pathways encompasses the nature of the phagocytic particle, the site from which macrophages are obtained, their response to activating agents and the mechanism through which the cell population alters its phagocytic potential. [source] Use of a ,-glucan hydrocolloidal suspension in the manufacture of low-fat Cheddar cheese: manufacture, composition, yield and microstructureINTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 1 2004G. Konuklar Summary Low-fat Cheddar cheese was manufactured using a , -glucan, hydrocolloidal fat replacer denoted as Nutrim. The composition, production efficiency, microstructure, and utility of replacing fat with Nutrim were examined. Cheese samples (designated as Nutrim-I, and Nutrim-II) containing Nutrim were produced with mean fat levels of 6.84 and 3.47%, respectively. A low-fat cheese was also produced as a control with a mean fat level of 11.2%. Nutrim-II cheese had significantly higher moisture, salt, and ash contents as compared with the low-fat control cheese. The low-fat control cheese had a higher yield normalized for 54% moisture and 1.5% salt content as compared with the Nutrim-II cheese. Scanning electron microscopy revealed smaller and more uniform fat droplet voids in the Nutrim cheese than the low-fat control, and a more dense, noncontinuous background protein matrix with globular clusters suggesting a physical buffering afforded by the presence of the , -glucan hydrocolloid or its associated water. [source] Influence of dietary ß-glucan on growth performance, lymphocyte proliferation, specific immune response and haptoglobin plasma concentrations in pigsJOURNAL OF ANIMAL PHYSIOLOGY AND NUTRITION, Issue 1-2 2003S. Hiss Summary Immunomodulatory feed additives might offer alternatives to anti-microbial growth promoters in swine production. The present study was conducted to assess the effects of ,-1,3/1,6 glucans, i.e. of specific yeast cell wall components, on immune function and growth performance in pigs. After weaning at 4 weeks of age, 75 piglets were allocated to 3 different groups for 4 weeks, the diet was supplemented with 0, 0.015 or 0.03% of ,-glucan, respectively. All animals were vaccinated against porcine reproductive and respiratory syndrome (PRRS). After 4 weeks, average daily gains (ADG) of ,-glucan treated pigs were not different from the controls. Feed intake was tendentiously (p < 0.1) increased at 0.03%,-glucan, without alteration of feed efficiency. Serum haptoglobin concentrations at the end of the 4 week treatment were increased in all groups when compared to the initial levels (p < 0.001), without differences between the groups (p > 0.05). Haptoglobin levels were inversely related to ADG. Lymphocyte proliferation indices were not different in control and treatment groups. Specific vaccination responses, as quantified by the PRRS antibody titres occurred in all animals, but no relation with ,-glucan feeding was observed. Our results indicate marginal benefits of ,-glucan supplements for growth performance and no effect on the immune parameters tested. The observed trend towards increased feed intake needs further elucidation. [source] Structural stability of Sclerotium rolfsii ATCC 201126 ,-glucan with fermentation time: a chemical, infrared spectroscopic and enzymatic approachJOURNAL OF APPLIED MICROBIOLOGY, Issue 1 2009J.I. Fariña Abstract Aims:,Sclerotium rolfsii ATCC 201126 exopolysaccharides (EPSs) recovered at 48 h (EPS I) and 72 h (EPS II) of fermentation, with differences in rheological parameters, hydrogel topography, salt tolerance, antisyneresis, emulsifying and suspending properties, were subjected to a polyphasic characterization in order to detect structural divergences. Methods and Results:, Fermenter-scale production led to productivity (Pr) and yield (YP/C) values higher at 48 h (Pr = 0·542 g l,1 h,1; YP/C = 0·74) than at 72 h (Pr = 0·336 g l,1 h,1; YP/C = 0·50). Both EPSs were neutral glucose-homopolysaccharides with a ,-(1,3)-glycosidic backbone and single ,-(1,6)-glucopyranosyl sidechains regularly attached every three residues in the main chain, as revealed by chemical analyses. The infra-red diagnostic peak at 890 cm,1 confirmed ,-glycosidic linkages, while gentiobiose released by ,-(1,3)-glucanases confirmed single ,-1,6-glycosidic branching for both EPSs. Conclusions:, The true modular repeating unit of S. rolfsii ATCC 201126 scleroglucan could be resolved. Structural stability was corroborated and no structural differences could be detected as to account for the variations in EPSs behaviour. Significance and Impact of the Study:, Recovery of S. rolfsii ATCC 201126 scleroglucan at 48 h might be considered based on better fermentation kinetic parameters and no detrimental effects on EPS structural features. [source] Evaluation of the fermentability of oat fractions obtained by debranning using lactic acid bacteriaJOURNAL OF APPLIED MICROBIOLOGY, Issue 4 2008G. Kedia Abstract Aims:, The overall kinetics of the fermentation of four oat fractions obtained by debranning using three potentially probiotic lactic acid bacteria were investigated. The main objective was to study the suitability of these fractions as fermentation media for the growth and the metabolic production of bacteria isolated from human intestine. Methods and Results:, The cell growth, lactic acid production and substrate uptakes of the three lactobacilli was monitored for 30 h. An unstructured mathematical model was used to describe and fit the experimental data. In the medium from fraction B (1,3% pearlings or ,-glucan-rich fraction) all strains reached the highest cell populations, maximum growth rates and maximum lactic acid productions. This could be because of the high levels of total fibre and ,-glucan of this fraction. Limited growth and lactic acid formation was found in medium A (0,1% pearlings or bran-rich fraction). Conclusions:, Medium B (1,3% pearling fraction) is the most suitable for fermentation and produces considerably higher probiotic cell concentrations. Significance and Impact of the Study:, Debranning technology could be used to separate fractions from cereal grains for the production of functional formulations with higher probiotic levels than the ones that were obtained with the whole grain. [source] Bioethanol production from bio- organosolv pulps of Pinus radiata and Acacia dealbataJOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 8 2007Claudio Muñoz Abstract Wood chips from Pinus radiata and Acacia dealbata were pretreated with the white-rot fungi Ceriporiopsis subvermispora and Ganoderma australe, respectively, for 30 days at 27 °C and 55% relative humidity, followed by an organosolv delignification with 60% ethanol solution at 200 °C for 1 h to produce pulps with high cellulose and low lignin content. Biotreatment for 30 days was chosen based on low weight and cellulose losses (lower than 4%) and lignin degradation higher than 9%. After organosolv delignification, pulp yield for P. radiata and A. dealbata pulps was 45,49% and 31,51%, respectively. P. radiata bio-pulps showed higher glucan (93%) and lower lignin content (6%) than control pulps (82% glucan and 13% lignin). A. dealbata bio-pulps also showed higher glucan (95%) and lower lignin content (2%) than control pulps (92% glucan and 4% lignin). Pulp suspensions at 2% consistency were submitted either to separate enzymatic hydrolysis and fermentation (SHF) or simultaneous enzymatic saccharification and fermentation (SSF) for bioethanol production. The yeast Saccharomyces cerevisiae was used for fermentation. Glucan-to-glucose conversion in the enzymatic hydrolysis of control and bio-pulps of P. radiata was 55% and 100%, respectively, and it was 100% for all pulp samples case of A. dealbata. The highest ethanol yield (calculated as percentage of theoretical yield) during SHF of P. radiata control and bio-pulps was 38% and 55%, respectively, and for A. dealbata control and bio-pulps 62% and 69%, respectively. The SSF of P. radiata control and bio-pulps yielded 10% and 65% of ethanol, respectively, and 77% and 82% for A. dealbata control and bio-pulps, respectively. In wood basis, the maximum conversion obtained (g ethanol per kg wood) in SHF was 37% and 51% (for P. radiata and A. dealbata pulps, respectively) and 44% and 65% in SSF (for P. radiata and A. dealbata pulps, respectively) regarding the theoretical yield. The low wood-to-ethanol conversion was associated with low pulp yield (A. dealbata pulps), high residual lignin amount (P. radiata pulps) and the low pulp consistency (2%) used for SHF and SSF. Copyright © 2007 Society of Chemical Industry [source] Adjuvant effect of mushroom glucan and bovine lactoferrin upon Aeromonas hydrophila vaccination in catla, Catla catla (Hamilton)JOURNAL OF FISH DISEASES, Issue 6 2006D Kamilya Abstract Mushroom glucan and bovine lactoferrin (Lf), known for their immunostimulatory potential, were used as adjuvant in conjunction with a formalin-killed Aeromonas hydrophila vaccine in catla, Catla catla. In vitro antigen-specific responsiveness of catla leucocytes and protective responses against experimental challenge with homologous antigen were monitored following immunization. Antigen-specific proliferation, ,macrophage activating factor' (MAF) production and antibody production were significantly higher in fish injected with glucan adjuvanted vaccine. Lf adjuvanted preparations showed a weak proliferative response and MAF production, although the antibody production was significantly higher than the controls. A good degree of protection was achieved with the glucan adjuvanted vaccine. However, in spite of producing significant anti- A. hydrophila antibody, Lf adjuvanted vaccine did not confer any protection following challenge with A. hydrophila. The potential of adjuvanticity of mushroom glucan and bovine Lf in intraperitoneal vaccination is discussed. [source] PUFFING AND JET COOKING AFFECT SOLUBILITY AND MOLECULAR WEIGHT OF BARLEY ,-GLUCANS,JOURNAL OF FOOD PROCESSING AND PRESERVATION, Issue 6 2004A.P. KLAMCZYNSKI ABSTRACT Foods containing barley or oats are often marketed as healthy because of the dietary fiber (1,3) (1,4)-,-D-glucan. Processing conditions can affect the molecular structure of these dietary fibers, which in turn affect quality and properties of the products. In this study, the effect of puffing and jet cooking conditions on changes in the solubility and molecular weight of barley ,-glucans was investigated. Barley flour was processed in a pasta extruder to produce particles similar in size and shape to rice. These particles were puffed at 230, 250 and 270C for 6, 8 and 10 s in a rice cake machine. Solubility and molecular weight of barley ,-glucans were determined by using water extracts (25 or 65C). The amount of ,-glucan extracted in water at 25C increased from 41.1% in cakes puffed at 230C/6 s to 69.7% in cakes puffed at 270C/10 s. The amount of ,-glucan extracted in water at 65C increased from 63.6% in samples puffed at 230C/6 s to 99.1% in samples puffed at 270C/10 s. The molecular weight of ,-glucans in barley was reduced by puffing and jet cooking treatments. [source] Effects of ,-Glucan Addition to a Probiotic Containing YogurtJOURNAL OF FOOD SCIENCE, Issue 7 2007T. Vasiljevic ABSTRACT:, This study investigated the effects of addition of ,-glucan from 2 different cereal sources (oat and barley) on growth and metabolic activity of Bifidobacterium animalis ssp. lactis (Bb-12Ô) as determined by plating on a selective medium in yogurt during prolonged cold storage. These yogurt batches were compared to unsupplemented and inulin supplemented controls. All batches were also assessed for syneresis. Oat ,-glucan addition resulted in improved probiotic viability and stability comparable to that of inulin. It also enhanced lactic and propionic acid production. The barley ,-glucan addition suppressed proteolytic activity more than that from oat. These improvements were hindered by greater syneresis caused likely by thermodynamic incompatibility. Small amplitude oscillatory measurements of acidified model mixture of ,-glucan/skim milk solids showed formation of casein gel within the ,-glucan network. Binary mixtures of ,-glucan and skim milk solids had apparent pseudoplastic and non-Newtonian behavior governed mainly by ,-glucan contribution. Above critical concentrations, the mixtures underwent phase separation with the lower phase rich in protein. The phase diagram also showed that the addition of ,-glucan may be possible at or below 0.24 w/w%. [source] Anti-diabetic effect of an ,-glucan from fruit body of maitake (Grifola frondosa) on KK-Ay miceJOURNAL OF PHARMACY AND PHARMACOLOGY: AN INTERNATI ONAL JOURNAL OF PHARMACEUTICAL SCIENCE, Issue 4 2007Lei Hong We have evaluated the anti-diabetic effect of a ,-glucan (MT-,-glucan) from the fruit body of maitake mushrooms (Grifola frondosa) on KK-Ay mice (a kind of genetical type 2 diabetes animal model). The effects of MT-,-glucan (450 or 150 mg kg,1) on diabetic mice were investigated by observing the changes in body weight, the level of fasting plasma glucose, glycosylated serum protein (GSP), hepatic glycogen, serum insulin, triglycerides, cholesterol, free fatty acid, liver superoxide dismutase (SOD), glutathione peroxidase (GSHpx), reduced glutathione (GSH) and malondialdehyde (MDA). Moreover, the binding capacity of insulin receptors on liver crude plasma membranes was assayed and histopathological changes in the pancreas were observed. Treatment with MT-,-glucan significantly decreased the body weight, level of fasting plasma glucose, GSP, serum insulin, triglycerides, cholesterol, free fatty acid and MDA content in livers. Treatment with MT-,-glucan significantly increased the content of hepatic glycogen, GSH and the activity of SOD and GSHpx. Moreover, the insulin binding capacity to liver crude plasma membranes increased and histopatho-logical changes in the pancreas were ameliorated in the treatment group. These data suggest that MT-,-glucan has an anti-diabetic effect on KK-Ay mice, which might be related to its effect on insulin receptors (i.e., increasing insulin sensitivity and ameliorating insulin resistance of peripheral target tissues). [source] Anti-inflammatory, analgesic and anti-oedematous effects of Lafoensia pacari extract and ellagic acidJOURNAL OF PHARMACY AND PHARMACOLOGY: AN INTERNATI ONAL JOURNAL OF PHARMACEUTICAL SCIENCE, Issue 9 2006Alexandre P. Rogerio Lafoensia pacari St. Hil. (Lythraceae) is used in traditional medicine to treat inflammation. Previously, we demonstrated the anti-inflammatory effect that the ethanolic extract of L. pacari has in Toxocara canis infection (a model of systemic eosinophilia). In this study, we tested the antiinflammatory activity of the same L. pacari extract in mice injected intraperitoneally with ,-glucan present in fraction 1 (F1) of the Histoplasma capsulatum cell wall (a model of acute eosinophilic inflammation). We also determined the anti-oedematous, analgesic and anti-pyretic effects of L. pacari extract in carrageenan-induced paw oedema, acetic acid writhing and LPS-induced fever, respectively. L. pacari extract significantly inhibited leucocyte recruitment into the peritoneal cavity induced by ,-glucan. In addition, the L. pacari extract presented significant analgesic, anti-oedematous and anti-pyretic effects. Bioassay-guided fractionation of the L. pacari extract in the F1 model led us to identify ellagic acid. As did the extract, ellagic acid presented anti-inflammatory, anti-oedematous and analgesic effects. However, ellagic acid had no anti-pyretic effect, suggesting that other compounds present in the plant stem are responsible for this effect. Nevertheless, our results demonstrate potential therapeutic effects of L. pacari extract and ellagic acid, providing new prospects for the development of drugs to treat pain, oedema and inflammation. [source] Quantification of uncertainty using Bayesian and bootstrap models to simulate the impact of nitrogen fertilisation on ,-glucan levels in barleyJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 11 2009Marta Fontana Abstract BACKGROUND: ,-Glucans have enjoyed renewed interest as a functional food ingredient, with current attention focused on optimising ,-glucan levels in finished products without compromising final product quality. In order to measure the uncertainty about the level of ,-glucans in barley, two different statistical methods (Bayesian inference and Bootstrap technique) were applied to measured levels of ,-glucan in three different varieties of barley grain (n = 83). RESULTS: The resulting probability density distributions were similar for the full data set and also when applied to smaller sample sizes, highlighting the potential for either method in quantifying the total uncertainty in ,-glucan levels. Bayesian inference was used to model the effect of nitrogen treatment on ,-glucan and protein contents in barley. The model found that a low level of fertilisation (50 kg N ha,1) did not have a significant effect on ,-glucan or protein content. However, fertilisation above this level did result in an increase in ,-glucan and protein levels, the effect seeming to plateau at 100 kg N ha,1. In addition, the uncertainty distributions were significantly different for two consecutive years of data, highlighting the potential environmental influence on ,-glucan content. CONCLUSION: The model developed in this study could be a useful tool for processors to quantify the uncertainty about the initial level of ,-glucan in barley and to evaluate the influence of environmental factors, thus enabling them to formulate their ingredient base to optimise levels of ,-glucan without compromising final product quality. Copyright © 2009 Society of Chemical Industry [source] The effects of refined barley ,-glucan on the physico-structural properties of low-fat dairy products: curd yield, microstructure, texture and rheologyJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 10 2004Carmen M Tudorica Abstract The beneficial role of dietary fibre in human nutrition has lead to a growing demand for incorporation of novel fibres, particularly barley ,-glucans, into foods. Barley ,-glucans are regarded as dietary fibre ingredients that are partially soluble in water. The aim of the present work was to investigate the possibility of using barley ,-glucan in milk systems in relation to the coagulation properties of milk containing ,-glucan, and to the rheology, texture and microstructure of fresh curds. The rate of coagulation and optimum coagulum cutting time were evaluated using rheological measurements. Results show that coagulation/gelation time of the milk can be reduced significantly with the incorporation of ,-glucan; curd yield increased and the viscoelastic properties of the curd were altered with ,-glucan additions. The relationships between curd rheological behaviour and its microstructure are discussed in relation to use of novel hydrocolloids in dairy processing. The results suggest that barley ,-glucan has the potential to be used as a fat replacer in low-fat dairy systems. Copyright © 2004 Society of Chemical Industry [source] Isolation, structural features and rheological properties of water-extractable ,-glucans from different Greek barley cultivarsJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 10 2004Maria Irakli Abstract ,-Glucans were isolated from six Greek barley cultivars (Persefoni, Kos, Thessaloniki, Athinaida, Dimitra and Triptolemos) by water extraction at 47 °C, enzymatic removal of starch and protein and subsequent precipitation of the water-soluble ,-glucans with 37% (w/v) ammonium sulfate saturation. The purity of barley ,-glucans was high (>93% dry basis) with some small contamination by protein (<3.84%). The molecular size of the ,-glucan isolates was determined by high-performance size-exclusion chromatography (HPSEC); the weight-average molecular weights and the intrinsic viscosities ranged between 0.45 × 106 and 1.32 × 106 and 2.77 and 4.11 dl g,1, respectively. Structural features of barley ,-glucans were revealed by 13C NMR spectroscopy and high-performance anion-exchange chromatography (HPAEC) of the oligomers released by the hydrolytic action of lichenase. Lichenase degradation showed that ,-glucans from all barley cultivars consisted of blocks of cellotriosyl and cellotetraosyl units, accounting for 90.6,92.3% of the total oligomers released, with a molar proportion of these units between 2.31 and 2.77. Rheological measurements of aqueous solutions/dispersions of ,-glucans showed the behaviour of non-interacting polysaccharides and a transition from the typical viscoelastic response to gel-like properties after a time period that depended on the molecular size of the polysaccharide. The lowest molecular size ,-glucans from the Triptolemos cultivar showed shorter gelation times than their higher molecular weight counterparts. The effect of sugar incorporation (glucose, fructose, sucrose, xylose and ribose), at a concentration of 30% (w/v), to the ,-glucans gels (6% w/v) on compression parameters seemed to be related to the type of sugar used; the pentose sugars substantially reduced gel firming. Copyright © 2004 Society of Chemical Industry [source] In vitro fermentation of cereal dietary fibre carbohydrates by probiotic and intestinal bacteriaJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 8 2002Ross Crittenden Abstract A range of probiotic and other intestinal bacteria were examined for their ability to ferment the dietary fibre carbohydrates ,-glucan, xylan, xylo-oligosaccharides (XOS) and arabinoxylan. ,-Glucan was fermented by Bacteroides spp and Clostridium beijerinckii but was not fermented by lactobacilli, bifidobacteria, enterococci or Escherichia coli. Unsubstituted xylan was not fermented by any of the probiotic bacteria examined. However, many Bifidobacterium species and Lactobacillus brevis were able to grow to high yields using XOS. XOS were also efficiently fermented by some Bacteroides isolates but not by E coli, enterococci, Clostridium difficile, Clostridium perfringens or by the majority of intestinal Lactobacillus species examined. Bifidobacterium longum strains were able to grow well using arabinoxylan as the sole carbon source. These organisms hydrolysed and fermented the arabinosyl residues from arabinoxylan but did not substantially utilise the xylan backbone of the polysaccharide. Arabinoxylan was not fermented by lactobacilli, enterococci, E coli, C perfringens or C difficile and has potential to be an applicable carbohydrate to complement probiotic Bif longum strains in synbiotic combinations. © 2002 Society of Chemical Industry [source] Immune Response and Resistance to Stress and Edwardsiella ictaluri Challenge in Channel Catfish, Ictalurus punctatus, Fed Diets Containing Commercial Whole-Cell Yeast or Yeast SubcomponentsJOURNAL OF THE WORLD AQUACULTURE SOCIETY, Issue 1 2007Thomas L. Welker Dietary supplementation of yeast or yeast subcomponents (YYS) as commercial preparations of ,-glucan (MacroGard®; Biotec-Mackzymal, Tromsø, Norway; and Betagard A®; Aqua-In-Tech, Inc., Seattle, WA, USA), mannan oligosaccharide (Bio-MosÔ Aqua Grade; Alltech, Nicholasville, KY, USA), or whole-cell Saccharomyces cerevisiae (Levucell SB20®; Lallemand Animal Nutrition, Milwaukee, WI, USA) at the manufacturer's recommended levels was evaluated on the physiological performance of juvenile channel catfish, Ictalurus punctatus. Fish were fed YYS diets for 4 wk, followed by 2 wk of control diet. Fish were sampled at the end of each feeding period (4 and 6 wk) to measure hematological and immune parameters and growth and to determine the effects of dietary ,-glucan on resistance to Edwardsiella ictaluri infection and to low-water stress (6 wk). Supplementation of YYS in diets did not affect growth performance, hematology, or immune function. Survival from E. ictaluri infection was from 5 to 17.5% higher in fish fed YYS diets than in the control group, but the increases were not significant. Some improvement in stress resistance was observed in YYS-fed catfish after exposure to low-water stress. Stress reduction in fish fed diets supplemented with yeast subcomponents has been reported previously, but thus far, no explanation has been proposed for this effect. The present study and the previously published research suggest that dietary YYS supplementation does not appear to improve resistance of channel catfish to E. ictaluri. [source] Preparation of microparticulate ,-glucan from Saccharomyces cerevisiae for use in immune potentiationLETTERS IN APPLIED MICROBIOLOGY, Issue 4 2002K.W. Hunter Jr Aims: To develop a method for the preparation of an immunologically active, homogeneous, nonaggregated, microparticulate ,-glucan-containing material from the budding yeast Saccharomyces cerevisiae. Methods and Results: Using a combination of sonication and spray-drying, a homogeneous preparation of 1,2-µ diameter ,-glucan-containing particles was made from alkali- and acid-insoluble yeast cell wall material. This microparticulate ,-glucan remained in suspension longer and, following oral administration at 0·1 mg kg,1 for 14 d, enhanced phagocytosis of mouse peritoneal macrophages significantly better than did aggregated ,-glucan particles. Conclusions: A new sonication and spray-drying method can be employed to overcome the problem of aggregation of ,-glucan microparticles in aqueous media. Significance and Impact of the Study: A microparticulate form of ,-glucan that remains in suspension longer for pharmaceutical applications and has superior immune potentiation characteristics has been developed. [source] Preemptive treatment of fungal infection: has its time arrived in liver transplantation?LIVER TRANSPLANTATION, Issue 3 2008James D. Perkins M.D. Special Editor Background Invasive fungal infection remains a major challenge in liver transplantation and the mortality rate is high. Early diagnosis and treatment are required for better results. Patients We prospectively measured plasma (1 , 3),-d glucan (BDG) levels in 180 living donor liver transplant recipients for 1 year after surgery. Fungal infection was defined as proposed by the European Organization for Research and Treatment of Cancer/Mycoses Study Group. Preemptive treatment (intravenous fluconazole and trimethoprim-sulfamethoxazole) was started when the BDG level was greater than 40 pg/ml. Results Twenty-four patients (13%) were diagnosed with invasive fungal infection. The responsible pathogens included Candida spp. in 14 cases, Aspergillus fumigatus in 5, Cryptococcus neoformans in 3, and Pneumocystis jiroveci in 2. Preemptive treatment was performed in 22% of patients (n = 40). Renal impairment and mild gastrointestinal intolerance due to the drugs were observed in 28% (11/40) of patients during treatment. Among them 14 patients were diagnosed with fungal infection including seven candidiasis, five aspergillosis, and two Pneumocystis jiroveci pneumonia. The sensitivity and specificity of BDG for overall fungal infection was 58% and 83%, respectively, with a positive predictive value of 35% and a negative predictive value of 93%, and a positive likelihood ratio of 3.41 and a negative likelihood ratio of 1.98. The overall mortality for fungal infection in our series was 0.6%. Conclusion Although the sensitivity and positive predictive value were low, the low mortality rate after fungal infection and the mild side effects of the preemptive treatment might justify our therapeutic strategy. Based on the effectiveness, this strategy warrants further investigation. [source] | |||||||||||||||||||||||||||||||||||||