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Maija Tenkanen - One of the best experts on this subject based on the ideXlab platform.
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interactions between fava bean protein and Dextrans produced by leuconostoc pseudomesenteroides dsm 20193 and weissella cibaria sj 1b
Carbohydrate Polymers, 2018Co-Authors: Yan Xu, Leena Pitkänen, Rossana Coda, Kati Katina, Maija TenkanenAbstract:Abstract The aim of this study was to study the interactions between Dextran and fava bean protein. Two Dextrans produced by Leuconostoc pseudomesenteroides DSM 20193 and Weissella cibaria Sj 1b were purified and mixed with fava bean protein isolate (FPI) in water or in different buffers. The two isolated Dextrans presented a typical Dextran structure, mainly α-(1 → 6) linkages (above 95%) and few α-(1 → 3) branches, but they differed in molar mass and conformation. Dry-heating incubation of FPI and Dextran mixture facilitated the conjugation of Dextran to FPI through the Maillard reaction. Both mixed and conjugated systems were further heat-treated, and different influences of the formed covalent bonds on rheological properties were observed. The W. cibaria Sj 1b Dextran had a much higher gel-strengthening ability than the Ln. pseudomesenteroides DSM 20193 Dextran. The intermolecular FPI-Dextran interactions played an important role in stabilizing the mixed systems at different pH.
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Rye bran as fermentation matrix boosts in situ Dextran production by Weissella confusa compared to wheat bran
Applied Microbiology and Biotechnology, 2016Co-Authors: Ilkka Kajala, Rossana Coda, Shraddha Shukla, Arun Goyal, Maija Tenkanen, Jari Mäkelä, Ndegwa Henry Maina, Riikka Juvonen, Päivi Ekholm, Kati KatinaAbstract:The consumption of fiber-rich foods such as cereal bran is highly recommended due to its beneficial health effects. Pre-fermentation of bran with lactic acid bacteria can be used to improve the otherwise impaired flavor and textural qualities of bran-rich products. These positive effects are attributed to enzymatic modification of bran components and the production of functional metabolites like organic acids and exopolysaccharides such as Dextrans. The aim of this study was to investigate Dextran production in wheat and rye bran by fermentation with two Weissella confusa strains. Bran raw materials were analyzed for their chemical compositions and mineral content. Microbial growth and acidification kinetics were determined from the fermentations. Both strains produced more Dextran in rye bran in which the fermentation-induced acidification was slower and the acidification lag phase longer than in wheat bran. Higher Dextran production in rye bran is expected to be due to the longer period of optimal pH for Dextran synthesis during fermentation. The starch content of wheat bran was higher, which may promote isomaltooligosaccharide formation at the expense of Dextran production. W. confusa Cab3 produced slightly higher amounts of Dextran than W. confusa VTT E-90392 in all raw materials. Fermentation with W. confusa Cab3 also resulted in lower residual fructose content which has technological relevance. The results indicate that wheat and particularly rye bran are promising matrices for producing technologically significant amounts of Dextran, which facilitates the use of nutritionally valuable raw bran in food applications.
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challenges in analysis of high molar mass Dextrans comparison of hpsec asflfff and dosy nmr spectroscopy
Carbohydrate Polymers, 2014Co-Authors: Leena Pitkänen, Sami Heikkinen, Paivi Tuomainen, Maija TenkanenAbstract:Dilute solutions of various Dextran standards, a high-molar mass (HMM) commercial Dextran from Leuconostoc spp., and HMM Dextrans isolated from Weissella confusa and Leuconostoc citreum were analyzed with high-performance size-exclusion chromatography (HPSEC), asymmetric flow field-flow fractionation (AsFlFFF), and diffusion-ordered NMR spectroscopy (DOSY). HPSEC analyses were performed in aqueous and dimethyl sulfoxide (DMSO) solutions, while only aqueous solutions were utilized in AsFlFFF and DOSY. The study showed that all methods were applicable to Dextran analysis, but differences between the aqueous and DMSO-based solutions were obtained for HMM samples. These differences were attributed to the presence of aggregates in aqueous solution that were less prevalent in DMSO. The study showed that DOSY provides an estimate of the size of HMM Dextrans, though calibration standards may be required for each experimental set-up. To our knowledge, this is the first study utilizing these three methods in analyzing HMM Dextrans.
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challenges in analysis of high molar mass Dextrans comparison of hpsec asflfff and dosy nmr spectroscopy
Carbohydrate Polymers, 2014Co-Authors: Leena Pitkänen, Sami Heikkinen, Paivi Tuomainen, Maija TenkanenAbstract:Dilute solutions of various Dextran standards, a high-molar mass (HMM) commercial Dextran from Leuconostoc spp., and HMM Dextrans isolated from Weissella confusa and Leuconostoc citreum were analyzed with high-performance size-exclusion chromatography (HPSEC), asymmetric flow field-flow fractionation (AsFlFFF), and diffusion-ordered NMR spectroscopy (DOSY). HPSEC analyses were performed in aqueous and dimethyl sulfoxide (DMSO) solutions, while only aqueous solutions were utilized in AsFlFFF and DOSY. The study showed that all methods were applicable to Dextran analysis, but differences between the aqueous and DMSO-based solutions were obtained for HMM samples. These differences were attributed to the presence of aggregates in aqueous solution that were less prevalent in DMSO. The study showed that DOSY provides an estimate of the size of HMM Dextrans, though calibration standards may be required for each experimental set-up. To our knowledge, this is the first study utilizing these three methods in analyzing HMM Dextrans.
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in situ production and analysis of weissella confusa Dextran in wheat sourdough
Food Microbiology, 2009Co-Authors: Kati Katina, Maija Tenkanen, Ndegwa Henry Maina, Riikka Juvonen, Liisa Virkki, Laura Flander, Liisa Johansson, Arja LaitilaAbstract:Several lactic acid bacteria belonging to the genera Leuconostoc, Lactobacillus, and Weissella have been introduced to wheat sourdough baking for in situ production of exopolysaccharides. This is considered a novel method for improving the shelf-life, volume and nutritional value of bread without additives. However, in situ production of exopolysaccharides during sourdough fermentation is challenged by simultaneous acidification due to metabolic activities of the bacteria, which may significantly diminish the positive technological impact of exopolysaccharides. In this study, the growth, activity and in situ production of Dextran by Weissella confusa VTT E-90392 in wheat sourdoughs were investigated. Furthermore, the influence of Dextran-enriched sourdoughs, at the addition level of 43%, on the subsequent bread quality was established. W. confusa efficiently produced Dextran from the added sucrose in wheat sourdough without strong acid production. A new specific enzyme-assisted method for in situ analysis of Dextran in sourdoughs was developed. With this method, we could for the first time proof significant (11-16 g/kg DW) production of polymeric Dextran in sourdoughs. Concomitant formation of shorter isomaltooligosaccharides by W. confusa was also detected. The produced Dextran significantly increased the viscosity of the sourdoughs. Application of Dextran-enriched sourdoughs in bread baking provided mildly acidic wheat bread with improved volume (up to 10%) and crumb softness (25-40%) during 6 days of storage. Hence, W. confusa is a promising new strain for efficient in situ production of Dextrans and isomaltooligosaccharides in sourdoughs without strong acidification.
Jur Strobos - One of the best experts on this subject based on the ideXlab platform.
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sodium ferric gluconate complex in sucrose safer intravenous iron therapy than iron Dextrans
American Journal of Kidney Diseases, 1999Co-Authors: Gerald Faich, Jur StrobosAbstract:Use of recombinant human erythropoietin in patients with end-stage renal disease has highlighted iron deficiency as the major cause of resistant anemia. The current mainstay of intravenous (i.v.) iron replacement therapy, iron Dextran, has been shown in prior studies to have a risk of serious life-threatening anaphylaxis of just under 1 per 100 patients exposed. The current study assessed the safety profile of an alternative i.v. iron, sodium ferric gluconate complex in sucrose (Ferrlecit), as compared with iron Dextrans. Sodium ferric gluconate complex in sucrose, a unique chemical preparation, has been in use since 1959, principally in Europe, at a rate of approximately 2.7 million i.v. doses per year (1992 to 1996) in Germany and Italy alone. For iron Dextran, usage in the United States was comparable--principally renal hemodialysis--and estimated from market sources at 3.0 million doses per year (1995). From 1976 to 1996, there were 74 allergic adverse events reported for sodium ferric gluconate complex in sucrose to the World Health Organization (WHO), German Health Bureau, and the manufacturer (all combined). For the years 1992 to 1996, sodium ferric gluconate complex in sucrose had an allergy event reporting rate of 3.3 allergy episodes per million doses per year compared with a similar rate of 8.7 reported allergy events per million doses per year for iron Dextran in the United States in 1995. Case fatalities for sodium ferric gluconate complex in sucrose and iron Dextran within these reports were then compared. For sodium ferric gluconate complex in sucrose, there were no reports of deaths over the entire period (1976 to 1996). However, for iron Dextrans, there were 31 fatalities among 196 allergy/anaphylaxis cases reported in the United States between 1976 and 1996, yielding a case-fatality rate of 15.8%. These data show that sodium ferric gluconate complex in sucrose, when compared with iron Dextrans in comparably sized patient usage populations with similar total rates of reporting of allergic events, has a significantly lower reported mortality rate (P < 0.001). Thus, the data justify usage of sodium ferric gluconate complex in sucrose as the safer iron replacement therapeutic agent.
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sodium ferric gluconate complex in sucrose safer intravenous iron therapy than iron Dextrans
American Journal of Kidney Diseases, 1999Co-Authors: Gerald Faich, Jur StrobosAbstract:Abstract Use of recombinant human erythropoietin in patients with end-stage renal disease has highlighted iron deficiency as the major cause of resistant anemia. The current mainstay of intravenous (IV) iron replacement therapy, iron Dextran, has been shown in prior studies to have a risk of serious life-threatening anaphylaxis of just under 1 per 100 patients exposed. The current study assessed the safety profile of an alternative IV iron, sodium ferric gluconate complex in sucrose (Ferrlecit), as compared with iron Dextrans. Sodium ferric gluconate complex in sucrose, a unique chemical preparation, has been in use since 1959, principally in Europe, at a rate of approximately 2.7 million IV doses per year (1992 to 1996) in Germany and Italy alone. For iron Dextran, usage in the United States was comparable—principally renal hemodialysis—and estimated from market sources at 3.0 million doses per year (1995). From 1976 to 1996, there were 74 allergic adverse events reported for sodium ferric gluconate complex in sucrose to the World Health Organization (WHO), German Health Bureau, and the manufacturer (all combined). For the years 1992 to 1996, sodium ferric gluconate complex in sucrose had an allergy event reporting rate of 3.3 allergy episodes per million doses per year compared with a similar rate of 8.7 reported allergy events per million doses per year for iron Dextran in the United States in 1995. Case fatalities for sodium ferric gluconate complex in sucrose and iron Dextran within these reports were then compared. For sodium ferric gluconate complex in sucrose, there were no reports of deaths over the entire period (1976 to 1996). However, for iron Dextrans, there were 31 fatalities among 196 allergy/anaphylaxis cases reported in the United States between 1976 and 1996, yielding a case-fatality rate of 15.8%. These data show that sodium ferric gluconate complex in sucrose, when compared with iron Dextrans in comparably sized patient usage populations with similar total rates of reporting of allergic events, has a significantly lower reported mortality rate ( P
Gerald Faich - One of the best experts on this subject based on the ideXlab platform.
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sodium ferric gluconate complex in sucrose safer intravenous iron therapy than iron Dextrans
American Journal of Kidney Diseases, 1999Co-Authors: Gerald Faich, Jur StrobosAbstract:Use of recombinant human erythropoietin in patients with end-stage renal disease has highlighted iron deficiency as the major cause of resistant anemia. The current mainstay of intravenous (i.v.) iron replacement therapy, iron Dextran, has been shown in prior studies to have a risk of serious life-threatening anaphylaxis of just under 1 per 100 patients exposed. The current study assessed the safety profile of an alternative i.v. iron, sodium ferric gluconate complex in sucrose (Ferrlecit), as compared with iron Dextrans. Sodium ferric gluconate complex in sucrose, a unique chemical preparation, has been in use since 1959, principally in Europe, at a rate of approximately 2.7 million i.v. doses per year (1992 to 1996) in Germany and Italy alone. For iron Dextran, usage in the United States was comparable--principally renal hemodialysis--and estimated from market sources at 3.0 million doses per year (1995). From 1976 to 1996, there were 74 allergic adverse events reported for sodium ferric gluconate complex in sucrose to the World Health Organization (WHO), German Health Bureau, and the manufacturer (all combined). For the years 1992 to 1996, sodium ferric gluconate complex in sucrose had an allergy event reporting rate of 3.3 allergy episodes per million doses per year compared with a similar rate of 8.7 reported allergy events per million doses per year for iron Dextran in the United States in 1995. Case fatalities for sodium ferric gluconate complex in sucrose and iron Dextran within these reports were then compared. For sodium ferric gluconate complex in sucrose, there were no reports of deaths over the entire period (1976 to 1996). However, for iron Dextrans, there were 31 fatalities among 196 allergy/anaphylaxis cases reported in the United States between 1976 and 1996, yielding a case-fatality rate of 15.8%. These data show that sodium ferric gluconate complex in sucrose, when compared with iron Dextrans in comparably sized patient usage populations with similar total rates of reporting of allergic events, has a significantly lower reported mortality rate (P < 0.001). Thus, the data justify usage of sodium ferric gluconate complex in sucrose as the safer iron replacement therapeutic agent.
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sodium ferric gluconate complex in sucrose safer intravenous iron therapy than iron Dextrans
American Journal of Kidney Diseases, 1999Co-Authors: Gerald Faich, Jur StrobosAbstract:Abstract Use of recombinant human erythropoietin in patients with end-stage renal disease has highlighted iron deficiency as the major cause of resistant anemia. The current mainstay of intravenous (IV) iron replacement therapy, iron Dextran, has been shown in prior studies to have a risk of serious life-threatening anaphylaxis of just under 1 per 100 patients exposed. The current study assessed the safety profile of an alternative IV iron, sodium ferric gluconate complex in sucrose (Ferrlecit), as compared with iron Dextrans. Sodium ferric gluconate complex in sucrose, a unique chemical preparation, has been in use since 1959, principally in Europe, at a rate of approximately 2.7 million IV doses per year (1992 to 1996) in Germany and Italy alone. For iron Dextran, usage in the United States was comparable—principally renal hemodialysis—and estimated from market sources at 3.0 million doses per year (1995). From 1976 to 1996, there were 74 allergic adverse events reported for sodium ferric gluconate complex in sucrose to the World Health Organization (WHO), German Health Bureau, and the manufacturer (all combined). For the years 1992 to 1996, sodium ferric gluconate complex in sucrose had an allergy event reporting rate of 3.3 allergy episodes per million doses per year compared with a similar rate of 8.7 reported allergy events per million doses per year for iron Dextran in the United States in 1995. Case fatalities for sodium ferric gluconate complex in sucrose and iron Dextran within these reports were then compared. For sodium ferric gluconate complex in sucrose, there were no reports of deaths over the entire period (1976 to 1996). However, for iron Dextrans, there were 31 fatalities among 196 allergy/anaphylaxis cases reported in the United States between 1976 and 1996, yielding a case-fatality rate of 15.8%. These data show that sodium ferric gluconate complex in sucrose, when compared with iron Dextrans in comparably sized patient usage populations with similar total rates of reporting of allergic events, has a significantly lower reported mortality rate ( P
Leena Pitkänen - One of the best experts on this subject based on the ideXlab platform.
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interactions between fava bean protein and Dextrans produced by leuconostoc pseudomesenteroides dsm 20193 and weissella cibaria sj 1b
Carbohydrate Polymers, 2018Co-Authors: Yan Xu, Leena Pitkänen, Rossana Coda, Kati Katina, Maija TenkanenAbstract:Abstract The aim of this study was to study the interactions between Dextran and fava bean protein. Two Dextrans produced by Leuconostoc pseudomesenteroides DSM 20193 and Weissella cibaria Sj 1b were purified and mixed with fava bean protein isolate (FPI) in water or in different buffers. The two isolated Dextrans presented a typical Dextran structure, mainly α-(1 → 6) linkages (above 95%) and few α-(1 → 3) branches, but they differed in molar mass and conformation. Dry-heating incubation of FPI and Dextran mixture facilitated the conjugation of Dextran to FPI through the Maillard reaction. Both mixed and conjugated systems were further heat-treated, and different influences of the formed covalent bonds on rheological properties were observed. The W. cibaria Sj 1b Dextran had a much higher gel-strengthening ability than the Ln. pseudomesenteroides DSM 20193 Dextran. The intermolecular FPI-Dextran interactions played an important role in stabilizing the mixed systems at different pH.
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challenges in analysis of high molar mass Dextrans comparison of hpsec asflfff and dosy nmr spectroscopy
Carbohydrate Polymers, 2014Co-Authors: Leena Pitkänen, Sami Heikkinen, Paivi Tuomainen, Maija TenkanenAbstract:Dilute solutions of various Dextran standards, a high-molar mass (HMM) commercial Dextran from Leuconostoc spp., and HMM Dextrans isolated from Weissella confusa and Leuconostoc citreum were analyzed with high-performance size-exclusion chromatography (HPSEC), asymmetric flow field-flow fractionation (AsFlFFF), and diffusion-ordered NMR spectroscopy (DOSY). HPSEC analyses were performed in aqueous and dimethyl sulfoxide (DMSO) solutions, while only aqueous solutions were utilized in AsFlFFF and DOSY. The study showed that all methods were applicable to Dextran analysis, but differences between the aqueous and DMSO-based solutions were obtained for HMM samples. These differences were attributed to the presence of aggregates in aqueous solution that were less prevalent in DMSO. The study showed that DOSY provides an estimate of the size of HMM Dextrans, though calibration standards may be required for each experimental set-up. To our knowledge, this is the first study utilizing these three methods in analyzing HMM Dextrans.
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challenges in analysis of high molar mass Dextrans comparison of hpsec asflfff and dosy nmr spectroscopy
Carbohydrate Polymers, 2014Co-Authors: Leena Pitkänen, Sami Heikkinen, Paivi Tuomainen, Maija TenkanenAbstract:Dilute solutions of various Dextran standards, a high-molar mass (HMM) commercial Dextran from Leuconostoc spp., and HMM Dextrans isolated from Weissella confusa and Leuconostoc citreum were analyzed with high-performance size-exclusion chromatography (HPSEC), asymmetric flow field-flow fractionation (AsFlFFF), and diffusion-ordered NMR spectroscopy (DOSY). HPSEC analyses were performed in aqueous and dimethyl sulfoxide (DMSO) solutions, while only aqueous solutions were utilized in AsFlFFF and DOSY. The study showed that all methods were applicable to Dextran analysis, but differences between the aqueous and DMSO-based solutions were obtained for HMM samples. These differences were attributed to the presence of aggregates in aqueous solution that were less prevalent in DMSO. The study showed that DOSY provides an estimate of the size of HMM Dextrans, though calibration standards may be required for each experimental set-up. To our knowledge, this is the first study utilizing these three methods in analyzing HMM Dextrans.
Zheng Han - One of the best experts on this subject based on the ideXlab platform.
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extradomain b fibronectin targeted Dextran based chemical exchange saturation transfer magnetic resonance imaging probe for detecting pancreatic cancer
Bioconjugate Chemistry, 2019Co-Authors: Zheng Han, Shuixing Zhang, Kenji Fujiwara, Jia Zhang, Jing Liu, Peter C M Van Zijl, Lei ZhengAbstract:A Dextran-peptide conjugate was developed for magnetic resonance (MR) molecular imaging of pancreatic ductal adenocarcinoma (PDAC) through its overexpressed microenvironment biomarker, extradomain-B fibronectin (EDB-FN). This new agent consists of diamagnetic and biocompatible Dextran and a targeting peptide. Dextrans can be directly detected by chemical exchange saturation transfer magnetic resonance imaging (CEST MRI) without the need for radionuclide or metallic labeling. In addition, large molecular weight Dextran, Dextran 10 (MW ∼ 10 kDa), provides an approximately 50 times higher sensitivity per molecule than a single glucose unit. The potential of this highly biocompatible diamagnetic probe is demonstrated in a murine syngeneic allograft PDAC tumor model. The biocompatibility and sensitivity of this new agent clearly show potential for a path to clinical translation.
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Extradomain‑B Fibronectin-Targeted Dextran-Based Chemical Exchange Saturation Transfer Magnetic Resonance Imaging Probe for Detecting Pancreatic Cancer
2019Co-Authors: Zheng Han, Shuixing Zhang, Kenji Fujiwara, Jia Zhang, Jing Liu, Peter C M Van Zijl, Lei Zheng, Guanshu LiuAbstract:A Dextran-peptide conjugate was developed for magnetic resonance (MR) molecular imaging of pancreatic ductal adenocarcinoma (PDAC) through its overexpressed microenvironment biomarker, extradomain-B fibronectin (EDB-FN). This new agent consists of diamagnetic and biocompatible Dextran and a targeting peptide. Dextrans can be directly detected by chemical exchange saturation transfer magnetic resonance imaging (CEST MRI) without the need for radionuclide or metallic labeling. In addition, large molecular weight Dextran, Dextran 10 (MW ∼ 10 kDa), provides an approximately 50 times higher sensitivity per molecule than a single glucose unit. The potential of this highly biocompatible diamagnetic probe is demonstrated in a murine syngeneic allograft PDAC tumor model. The biocompatibility and sensitivity of this new agent clearly show potential for a path to clinical translation
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characterization of tumor vascular permeability using natural Dextrans and cest mri
Magnetic Resonance in Medicine, 2018Co-Authors: Yuan Qiao, Zheng Han, Hanwei Chen, Renyuan Bai, Verena Staedtke, Kannie W Y Chan, Nirbhay N YadavAbstract:Purpose To investigate the use of natural Dextrans as nano-sized chemical exchange saturation transfer (CEST) MRI probes for characterizing size-dependent tumor vascular permeability. Methods Dextrans of different molecular weight (10, 70, 150, and 2000 kD) were characterized for their CEST contrast. Mice (N = 5) bearing CT26 subcutaneous colon tumors were injected intravenously with 10 kD (D10, 6 nm) and 70 kD (D70, 12 nm) Dextran at a dose of 375 mg/kg. The CEST-MRI signal in the tumors was assessed before and approximately 40 min after each injection using a dynamic CEST imaging scheme. Results All Dextrans of different molecular weights have a strong CEST signal with an apparent maximum of approximately 0.9 ppm. The detectability and effects of pH and saturation conditions (B1 and Tsat ) were investigated. When applied to CT26 tumors, the injection of D10 could produce a significant "dexCEST" enhancement in the majority of the tumor area, whereas the injection of D70 only resulted in an increase in the tumor periphery. Quantitative analysis revealed the differential permeability of CT26 tumors to different size particles, which was validated by fluorescence imaging and immunohistochemistry. Conclusions As a first application, we used 10- and 70-kD Dextrans to visualize the spatially variable, size-dependent permeability in the tumor, indicating that nano-sized Dextrans can be used for characterizing tumor vascular permeability with dexCEST MRI and, potentially, for developing Dextran-based theranostic drug delivery systems. Magn Reson Med 79:1001-1009, 2018. © 2017 International Society for Magnetic Resonance in Medicine.