Presence Of Galactomannan Research Articles

The effect of antifungal treatments on bronchoalveolar lavage galactomannan for the diagnosis of invasive fungal infections in patients with hematological malignancy: Single-center experience

Background Invasive fungal infections (IFI) mainly caused by aspergillus species are one of the leading causes of death in patients undergoing immunosuppressive therapy for hematological malignancies. The presence of galactomannan in bronchoalveolar lavage fluid (BAL GM) is an important diagnostic marker. Some of the factors affecting the BAL GM are still unknown. Antifungal treatment administered before or after BAL also affect BAL GM results. Methods To investigate the effect of BAL GM timing on the diagnosis of IFE, 100 patients receiving immunosuppressive therapy with hematological malignancy at the Uludağ University Faculty of Medicine, Hematology Department, and underwent BAL over a 3-year period with the suspicion of IFE as well as 127 BAL procedures of these patients were examined. Results There were 70 patients who started antifungal therapy before BAL and 30 patients who did not. BAL GM was found positive in 33 (47.1%) of the 70 patients who received antifungal therapy compared to 22 (73.3%) of the 30 patients who did not receive antifungal therapy. There was a significant difference between the two groups in terms of BAL GM positivity (p = 0.016). Subsequently, 127 BAL procedures of these 100 patients were evaluated. When the second, third, and subsequent BAL procedures of the same patients were included in the study, BAL GM was positive in 41 (46.6%) of the 88 procedures in patients who received treatment before BAL and in 25 (64.1%) of the 39 procedures in patients who did not receive treatment before BAL. The rate of BAL GM positivity did not differ between groups (p = 0.068). Conclusions The balance between reducing the risk by initiating early antifungal therapy and maximizing the diagnostic value of BAL GM should be evaluated individually for each patient.

CAMP signaling factors regulate carbon catabolite repression of hemicellulase genes in Aspergillus nidulans

Carbon catabolite repression (CCR) enables preferential utilization of easily metabolizable carbon sources, implying the presence of mechanisms to ensure discriminatory gene repression depending on the ambient carbon sources. However, the mechanisms for such hierarchical repression are not precisely understood. In this report, we examined how deletion of pkaA and ganB, which encode cAMP signaling factors, and creA, which encodes a well-characterized repressor of CCR, affects CCR of hemicellulase genes in the filamentous fungus Aspergillus nidulans. β-Xylanase production increased not only in ΔcreA but also in ΔpkaA and ΔganB, with the highest level observed in their double deletants, irrespective of the presence or absence of d-glucose. Expression of the β-xylanase genes in the presence of d-glucose was de-repressed in all the deletion mutants, with significantly higher tolerance against d-glucose repression in ΔpkaA and ΔganB than in ΔcreA. In the presence of galactomannan and d-glucose, partial de-repression of β-mannanase production was detected in ΔcreA, but not in ΔpkaA and ΔganB. The double deletion of creA/pkaA and creA/ganB led to earlier production. Release from d-glucose repression of the β-mannanase genes was partial in the single deletants, while nearly full de-repression was observed in ΔcreAΔpkaA and ΔcreAΔganB. The contribution of PkaA and GanB to CCR by d-xylose of the β-mannanase genes was very minor compared to that of CreA. Consequently, the present study revealed that cAMP signaling plays a major role in CCR of hemicellulase gene expression in a manner that is clearly independent from CreA.

Obtaining and characterization of modified mannan from the coffee sludge

Mannans are polysaccharides of natural origin. Their main chain consists of residues of D-mannose. They have an immunomodulatory effect, able to induce macrophage activation, inhibit tumor growth and virus development, normalize blood cholesterol, etc. Manooligosaccharides are effective prebiotics The main way to obtain mannan is to extract their alkaline solutions. This makes it impossible to use this polysaccharide in food technologe. This study proposes a biotechnological method of producing water-soluble mannan from coffee sludge. As a source of mannan used a by-product of obtaining instant coffee at the Odessa Combine Food Concentrates which is formed in the processing of coffee beans Arabica. The chemical composition of this coffee sludge was investigated. It is dominated by water-insoluble carbohydrates which are represented by hemicellulose polysaccharides and cellulose. Analysis of the monosaccharide composition of hemicelluloses showed that the hydrolyzate contains mannose, glucose and galactose residues in a ratio of 6: 0,5: 3., which may indicate the presence of galactomannan in their composition. The developed method involves the treatment of the coffee sludge with enzyme preparation with beta-mannanase activity. The process was carried out in aqueous medium at temperature 50 °C, varying the hydromodule in the range of 30… 50, the ratio of enzyme: substrate (1:25, 1:50 and 1:100) for 24…72 hours. This study presents the characteristics of the monomer composition and molecular weight distribution of polysaccharide samples obtained in this way. Only mannose was found in the hydrolyzate of water-soluble mannan. The rational conditions of enzymatic processing of raw materials are determined. The modified mannan is soluble in water. It contains the highest number of target fragments with a molecular weight of about 20 kDa which are considered to be the most physiologically active. Subsequently the modified mannan can be used in nanotechnology functional food ingredients and dietary supplements.

Exopolysaccharides from Aspergillus terreus: Production, chemical elucidation and immunoactivity

Aspergillus terreus, a fungus commonly used in pharmaceutical industry to produce lovastatin and other secondary metabolites, has been reported to have beneficial biological properties. In this study the exopolysaccharides (AT-EPS) produced by A. terreus were evaluated as potential modulators of certain functions of macrophages. The production parameters for EPS obtained from the liquid culture broth of the studied fungus were optimized using response surface methodology (RSM) and indicated good correlation between the experimental and predicted values. The optimum conditions for AT-EPS extraction included fermentation at 28 °C, pH 8.79, under 98 rpm of agitation, using 2.39% glucose (carbon source) and 0.957% ammonium nitrate (nitrogen source). Under these optimized conditions, AT-EPS production was 1.34 g/L medium. The chemical analyses showed that AT-EPS was composed by mannose (Man; 40.5 mol%), galactose (Gal; 35.2 mol%), and glucose (Glc; 24.3 mol%), and the spectroscopic (FTIR; NMR) and methylation analyses indicated the presence of galactomannans, β-1,3-glucans, and glycogen-like glucans. AT-EPS was tested on murine macrophages to verify its immunoactivity and the treated cells were able to produce nitric oxide, superoxide anion, TNF-α and interleukin 6 similarly to the positive control cells. Furthermore, the macrophages treated with AT-EPS showed activated-like morphological alterations.

Diagnosis of invasive fungal disease in hospitalized patients with chronic obstructive pulmonary disease

BackgroundThe role of culture-independent techniques (galactomannan, (1-3)-β-d-glucan) in the early diagnosis of invasive fungal diseases (IFD) is well assessed in hematological patients, but there are no clear conclusions in patients with chronic obstructive pulmonary disease (COPD). AimsTo study the usefulness of nonculture-based techniques in the diagnosis of IFD in COPD-patients at risk for IFD. MethodsA prospective observational study based on monitoring COPD patients at risk for IFD during 2007–2010 was carried out. The presence of galactomannan, (1-3)-β-d-glucan and an indirect immunofluorescence of Candida albicans germ tube specific antibodies (CAGTA) were performed. ResultsAmong 43 COPD patients, 16 (37.2%) were diagnosed with IFD: seven cases were proven IFD (five invasive candidemia – IC, one invasive aspergillosis – IA and a rhinocerebral zygomycosis) and nine probable IFD (seven IA and two IC). In the diagnosis of IC and IA, the negative predictive value (NPV) of (1-3)-β-d-glucan was 100%. Regarding CAGTA in IC, NPV was 96.2%. Finally, NPV of galactomannan in IA was 91.2%. The area under the ROC curve for (1-3)-β-d-glucan in IC and for the rest of the IFD cases was 0.86 (95% CI, 0.79–0.93) and 0.60 (95% CI, 0.43–0.77), for CAGTA in IC was 0.83 (95% CI, 0.74–0.91) and for galactomannan in IA was 0.71 (95% CI, 0.56–0.85). Positive (1-3)-β-d-glucan preceded the growth of Candida (average of 1.7 days) in blood culture. ConclusionsIn COPD patients at risk for IFD the assayed techniques are especially useful to rule out the presence of IFD.

Stability properties of different fenugreek galactomannans in emulsions prepared by high-shear and ultrasonic method

In this research we studied the emulsion stabilizing properties of different fenugreek galactomannan gums, types (FGA, FGB, FGH) in comparison to common stabilizers, guar and locust bean gum (GG and LBG). The fenugreek gums differ at galactomannan (FGH > FGA > FGB) and protein content (reverse order), as well as at odor, varying from odorless (FGH) to intense one (FGB). Emulsions were prepared by high speed (HS) and ultrasonic (US) homogenization method and creaming was evaluated during 10-day cold storage. Gum type at 0.25% concentration did not improve the stability of samples prepared by both methods, thus the serum index was high, ranging from 25 % to 39 %. The stability was enhanced at 0.5% gum, mainly attributed to viscosity increase. Particularly, the serum index varied between 3.5 and 20.7 % for ultrasonically treated samples, while for those treated by HS ranged from 4.9 to 35 %.US treatment was able to reduce the average droplet size of emulsions by a factor ∼2.7 in average. In the presence of galactomannans, the smallest droplets according to D50 were around 1.48 μm. However, the viscosity loss observed in US emulsions due to polysaccharide degradation ranged between 77 and 91 % in 1 %wt in gum solutions, resulting in relatively poor stability enhancement observed in US emulsions. Overall, the best results regarding stability against creaming were obtained for emulsions containing 0.5 %wt FGH, but the lowest droplet size was achieved in the absence of stabilizers.

Gelatin and galactomannan-based scaffolds: Characterization and potential for tissue engineering applications

In this work, we produced gelatin films containing different concentrations of galactomannan by casting solutions. The films were crosslinked by immersion in 30mM solution of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDC). The crosslinking of gelatin-containing films was confirmed by the reduction of free amine band intensity (3400–3200cm−1) in the GEL IR, as well as by the evaluation of its behavior when immersed in phosphate-buffer solution. The crosslinking of galactomannan film was confirmed by the formation of new ether bonds, as observed by increasing intensity of the band at 1148cm−1, and the reduction of OH band intensity (3600–3200cm−1). The presence of galactomannan and the crosslinking mediated by EDC were responsible to improve elasticity in the gelatin-based films. The samples did not show cytotoxicity during 24h or 48h. In addition, rat mesenchymal stem cells adhered to the films regardless of galactomannan concentration. The results indicated that the gelatin/galactomannan films are potential biomaterials for use as scaffolds for tissue engineering.

Serum galactomannan in cystic fibrosis patients colonized withAspergillusspecies

Cystic fibrosis patients are often colonized by Aspergillus species. Sera from 138 pediatric and adult cystic fibrosis patients were tested for the presence of galactomannan. All serum samples were negative for galactomannan and there was no difference among patients who were chronically, intermittently, and never colonized with Aspergillus.

The cell wall galactomannan antigen from Malassezia furfur and Malassezia pachydermatis contains β-1,6-linked linear galactofuranosyl residues and its detection has diagnostic potential

Lipophilic yeasts of the genus Malassezia are associated with several skin diseases, such as pityriasis versicolor, Malassezia folliculitis, seborrhoeic dermatitis and atopic dermatitis, and are also increasingly associated with catheter-related fungaemia. The cell wall components of pathogenic micro-organisms behave as an antigen and/or ligand of the innate immune response. Live cells of Malassezia furfur and Malassezia pachydermatis did not react with an anti-alpha-1,2-mannoside antibody. However, they showed a strong hydrophobicity and reactivity with an anti-beta-1,3-glucan antibody compared to those of C. albicans. The cell wall polysaccharides of M. furfur and M. pachydermatis were isolated and their structures analysed by (1)H and (13)C NMR experiments. Both polysaccharides were shown to be beta-1,6-linked linear galactofuranosyl polymers with a small amount of mannan. The presence of galactomannan on cells of Malassezia species has not been described previously. The galactomannan did not react with an anti-Aspergillus fumigatus monoclonal antibody which has specificity for beta-1,5-linked galactofuranosyl residues. An anti-M. furfur antibody strongly reacted with the galactomannans of M. furfur and M. pachydermatis, but did not react with the galactomannans of Trichophyton rubrum, A. fumigatus or Fonsecaea pedrosoi. The characteristics of the anti-M. furfur antibody suggest that there is potential for diagnosis of Malassezia infections by antigen detection.

Value of a single galactomannan determination (Platelia) for the diagnosis of invasive aspergillosis in non-hematological patients with clinical isolation ofAspergillusspp.

We studied 75 patients with non-hematological conditions from whom Aspergillus spp. were recovered from clinical specimens during the period March 2003 to August 2006. The patients were classified according to EORTC criteria and the presence of galactomannan (Platelia Aspergillus) in their sera was evaluated. Ten of these patients (13.3%) had proven or probable invasive aspergillosis, i.e., chronic obstructive pulmonary disease in five (50%), HIV infection in one (10%), lymphoma in one (10%), liver transplant in one (10%), solid malignancies in one (10%), and corticosteroid treatment in one (10%). The sensitivity, specificity, and positive and negative predictive values for the detection of galactomannan, using cut-offs of > or =0.5 ng/ml and > or =1 ng/ml were 60%/50%, 89.23%/100%, 46.15%/100%, and 93.55%/92.86% (p=0.001 and p<0.001), respectively. The determination of galactomannan in the sera of non-neutropenic patients could prove to be a useful microbiological finding when diagnosing invasive aspergillosis.

On the physico-chemical and dielectric properties of glutaraldehyde crosslinked galactomannan–collagen films

The effects of galactomannan, a plant polysaccharide widely distributed in nature, on the physicochemical properties of collagen films, were studied using infrared spectroscopy, dielectric spectroscopy, thermal analysis (DSC), swelling and scanning electron microscopy, with possible applications in biomedical, cosmetic and food industry. Infrared bands typical for collagen molecules (amide I, II and III) and galactomannan structure, present in the spectrum of films with 50% of galactomannan, showed that the gum was retained in the collagen fibers. The integrity of the triple helical structure of collagen was conserved in the mixture. The resulting films crosslinked with increasing amounts of glutaraldehyde (GA), when analysed by differential scanning calorimetry (DSC), showed that the reaction induced the presence of two structures, which were the result of the heterogeneous reaction of GA. The presence of galactomannan in the collagen films, increased the swelling, and this effect was inconsistent with GA increments. Scanning electron microscopy showed the entanglement of the galactomannan by fibers of collagen. The piezoelectric strain tensor element d 14, the elastic constant s 55, and the dielectric permittivity ε 11 as obtained for the galactomannan–collagen film were studied. Resonance measurement of the piezoelectric strain constant d 14 of galactomannan–collagen film (60%) gives 0.081 pC/N.

Glycosidases induced in Aspergillus tamarii. Secreted alpha-D-galactosidase and beta-D-mannanase.

An alpha-D-galactosidase (EC 3.2.1.22) and a beta-D-mannanase (EC 3.2.1.78), which were secreted into the growth medium when Aspergillus tamarii was cultivated in the presence of galactomannan, were purified by a procedure including chromatography on hydroxyapatite and DEAE-cellulose columns. Each of these enzymes showed a single protein band, corresponding to their respective activities, on polyacrylamide-gel electrophoresis. Both enzymes were shown to be glycoproteins containing N-acetylglucosamine, mannose and galactose, with molar proportions of 1:6:1.5 for alpha-D-galactosidase and 1:13:8 for beta-D-mannanase. Mr values as determined by polyacrylamide-gel electrophoresis in the presence of sodium dodecyl sulphate and by the electrophoretic method of Hedrick & Smith [(1968) Arch. Biochem. Biophys. 126, 155-164] were 56000 and 53000 respectively. The alpha-D-galactosidase differed markedly from the mycelial forms I and II studied in the preceding paper [Civas, Eberhard, Le Dizet & Petek (1984) Biochem. J. 219, 849-855] with regard to both its kinetic and structural properties.

Galactomannans and other soluble polysaccharides inSophoraseed

Abstract Seed of Sophora microphylla, S. prostrata, and S. tetraptera subsp. tetraptera from New Zealand, and of S. affinis, S. secundiflora, S. tomentosa, S. chrysophylla, and S. tetraptera subsp. howinsula from outside New Zealand, has been examined for the presence of galactomannan and other water-soluble polysaccharides. Only S. affinis seed contained galactomannan. Sophora secundiflora seed contained either starch or amyloid. All species except S. affinis contained water-soluble polysaccharides composed of galactose and arabinose. Results are considered in relation to Yakovlev's classification of Sophora and particularly to his inclusion of S. affinis and S. japonicum in a separate genus Styphnolobium.