GOLGI FRACTIONS PREPARED FROM RAT LIVER HOMOGENATES

PubMed Central

Ehrenreich, J. H.; Bergeron, J. J. M.; Siekevitz, P.; Palade, G. E.

1973-01-01

In devising a new procedure for the isolation of Golgi fractions from rat liver homogenates, we have taken advantage of the overloading with very low density lipoprotein (VLDL) particles that occurs in the Golgi elements of hepatocytes ∼90 min after ethanol is administered (0.6 g/100 g body weight) by stomach tube to the animals. The VLDLs act as morphological markers as well as density modifiers of these elements. The starting preparation is a total microsomal fraction prepared from liver homogenized (1:5) in 0.25 M sucrose. This fraction is resuspended in 1.15 M sucrose and loaded at the bottom of a discontinuous sucrose density gradient. Centrifugation at ∼13 x 106 g·min yields by flotation three Golgi fractions of density >1.041 and <1.173. The light and intermediate fractions consist essentially of VLDL-loaded Golgi vacuoles and cisternae. Nearly empty, often collapsed, Golgi cisternae are the main component of the heavy fraction. A procedure which subjects the Golgi fractions to hypotonic shock and shearing in a French press at pH 8.5 allows the extraction of the content of the Golgi elements and the subsequent isolation of their membranes by differential centrifugation. PMID:4356571

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lukeman, S.; Fanestil, D.

Although the PBS has been identified in many organs, its function and cellular location are speculative. Using rapid filtration, binding of (/sup 3/H)RO 5-4864 (*RO) (.75 nM) was assessed in four subcellular fractions (.3 mg/ml) derived from depapillated rat kidney by differential centrifugation: N (450g x 2 min), O (13,000 x 10), P (105,000 x 30), and S. The binding distribution was: N-18%, O-74%, P-6%, and S-2%. Marker enzyme analysis revealed that O was enriched in mitochondria (M), lysosomes (L), peroxisomes (P), and endoplasmic reticulum (ER), but not plasma membrane, and that N contained small amounts (10-15%) of markers formore » the above. Repeated washing of O removed ER enzymes but preserved *RO binding. O was further fractionated with centrifugation (57,000g x 4 hr) on a linear sucrose gradient (18-65%); *RO binding then comigrated with M but not P and L markers. Centrifugation of isolated M (5500 x 10 min) on another linear sucrose gradient (37-65%) gave low and high density bands, which contained 65% and 35% of *RO binding activity, resp. *RO binding in O was specific, saturable, reversible, and inhibited by diuretics. Inhibitors with the highest potency were indacrinone (K/sub d/ = 35 ..mu..M), hydrochlorothiazide (100 ..mu..M), and ethacrynic acid (325 ..mu..M). Low potency inhibitors (K/sub d/ greater than or equal to 1 mM) included amiloride, triamterene, furosemide, bumetanide, and ozolinone.« less

Sucrose lyophiles: a semi-quantitative study of residual water content by total X-ray diffraction analysis.

PubMed

Bates, S; Jonaitis, D; Nail, S

2013-10-01

Total X-ray Powder Diffraction Analysis (TXRPD) using transmission geometry was able to observe significant variance in measured powder patterns for sucrose lyophilizates with differing residual water contents. Integrated diffraction intensity corresponding to the observed variances was found to be linearly correlated to residual water content as measured by an independent technique. The observed variance was concentrated in two distinct regions of the lyophilizate powder pattern, corresponding to the characteristic sucrose matrix double halo and the high angle diffuse region normally associated with free-water. Full pattern fitting of the lyophilizate powder patterns suggested that the high angle variance was better described by the characteristic diffraction profile of a concentrated sucrose/water system rather than by the free-water diffraction profile. This suggests that the residual water in the sucrose lyophilizates is intimately mixed at the molecular level with sucrose molecules forming a liquid/solid solution. The bound nature of the residual water and its impact on the sucrose matrix gives an enhanced diffraction response between 3.0 and 3.5 beyond that expected for free-water. The enhanced diffraction response allows semi-quantitative analysis of residual water contents within the studied sucrose lyophilizates to levels below 1% by weight. Copyright © 2013 Elsevier B.V. All rights reserved.

Selective production of sealed plasma membrane vesicles from red beet (Beta vulgaris L.) storage tissue.

PubMed

Giannini, J L; Gildensoph, L H; Briskin, D P

1987-05-01

Modification of our previous procedure for the isolation of microsomal membrane vesicles from red beet (Beta vulgaris L.) storage tissue allowed the recovery of sealed membrane vesicles displaying proton transport activity sensitive to both nitrate and orthovanadate. In the absence of a high salt concentration in the homogenization medium, contributions of nitrate-sensitive (tonoplast) and vanadate-sensitive (plasma membrane) proton transport were roughly equal. The addition of 0.25 M KCl to the homogenization medium increased the relative amount of nitrate-inhibited proton transport activity while the addition of 0.25 M KI resulted in proton pumping vesicles displaying inhibition by vanadate but stimulation by nitrate. These effects appeared to result from selective sealing of either plasma membrane or tonoplast membrane vesicles during homogenization in the presence of the two salts. Following centrifugation on linear sucrose gradients it was shown that the nitrate-sensitive, proton-transporting vesicles banded at low density and comigrated with nitrate-sensitive ATPase activity while the vanadate-sensitive, proton-transporting vesicles banded at a much higher density and comigrated with vanadate-sensitive ATPase. The properties of the vanadate-sensitive proton pumping vesicles were further characterized in microsomal membrane fractions produced by homogenization in the presence of 0.25 M KI and centrifugation on discontinuous sucrose density gradients. Proton transport was substrate specific for ATP, displayed a sharp pH optimum at 6.5, and was insensitive to azide but inhibited by N'-N-dicyclohexylcarbodiimide, diethylstilbestrol, and fluoride. The Km of proton transport for Mg:ATP was 0.67 mM and the K0.5 for vanadate inhibition was at about 50 microM. These properties are identical to those displayed by the plasma membrane ATPase and confirm a plasma membrane origin for the vesicles.

Lesions of the dopaminergic innervation of the nucleus accumbens medial shell delay the generation of preference for sucrose, but not of sexual pheromones.

PubMed

Martínez-Hernández, José; Lanuza, Enrique; Martínez-García, Fernando

2012-01-15

Male sexual pheromones are rewarding stimuli for female mice, able to induce conditioned place preference. To test whether processing these natural reinforcing stimuli depends on the dopaminergic innervation of the nucleus accumbens, as for other natural rewards, we compare the effects of specific lesions of the dopaminergic innervation of the medial shell of the nucleus accumbens on two different appetitive behaviours, 'pheromone seeking' and sucrose preferential intake. Female mice, with no previous experience with either adult male chemical stimuli or with sucrose, received injections of 6-hydroxydopamine (or vehicle) in the medial shell of the accumbens. Then, we analyzed their preference for male soiled-bedding and their preferential intake of a sucrose solution, with particular emphasis on the dynamics of acquisition of both natural rewards. The results indicate that both lesioned and sham animals showed similar preference for male sexual pheromones, which was constant along the test (linear dynamics). In contrast, lesioned animals differed from sham operated mice in the dynamics of sucrose consumption in their first test of sucrose preference. Sham animals showed an initial sucrose preference followed by preference for water, which can be interpreted as sucrose neophobia. Lesioned animals showed no preference at the beginning of the test, and a delayed sucrose preference appeared followed by a delayed neophobia. The next day, during a second sucrose-preference test, both groups displayed comparable and sustained preferential sucrose intake. Therefore, dopamine in the medial shell of the nucleus accumbens has a different role on the reward of sexual pheromones and sucrose. Copyright © 2011 Elsevier B.V. All rights reserved.

Production of the short peptide surfactant DAMP4 from glucose or sucrose in high cell density cultures of Escherichia coli BL21(DE3).

PubMed

Bruschi, Michele; Krömer, Jens O; Steen, Jennifer A; Nielsen, Lars K

2014-08-19

Peptides are increasingly used in industry as highly functional materials. Bacterial production of recombinant peptides has the potential to provide large amounts of renewable and low cost peptides, however, achieving high product titers from Chemically Defined Media (CDM) supplemented with simple sugars remains challenging. In this work, the short peptide surfactant, DAMP4, was used as a model peptide to investigate production in Escherichia coli BL21(DE3), a classical strain used for protein production. Under the same fermentation conditions, switching production of DAMP4 from rich complex media to CDM resulted in a reduction in yield that could be attributed to the reduction in final cell density more so than a significant reduction in specific productivity. To maximize product titer, cell density at induction was maximized using a fed-batch approach. In fed-batch DAMP4 product titer increased 9-fold compared to batch, while maintaining 60% specific productivity. Under the fed-batch conditions, the final product titer of DAMP4 reached more than 7 g/L which is the highest titer of DAMP4 reported to date. To investigate production from sucrose, sucrose metabolism was engineered into BL21(DE3) using a simple plasmid approach. Using this strain, growth and DAMP4 production characteristics obtained from CDM supplemented with sucrose were similar to those obtained when culturing the parent strain on CDM supplemented with glucose. Production of a model peptide was increased to several grams per liter using a CDM medium with either glucose or sucrose feedstock. It is hoped that this work will contribute cost reduction for production of designer peptide surfactants to facilitate their commercial application.

LINEARIZATION OF EMPIRICAL RHEOLOGICAL DATA FOR USE IN COMPOSITION CONTROL OF MULTICOMPONENT FOODSTUFFS.

PubMed

Drake, Birger; Nádai, Béla

1970-03-01

An empirical measure of viscosity, which is often far from being a linear function of composition, was used together with refractive index to build up a function which bears a linear relationship to the composition of tomato paste-water-sucrose mixtures. The new function can be used directly for rapid composition control by linear vector-vector transformation.

Size-separation of silver nanoparticles using sucrose gradient centrifugation

DOE PAGES

Suresh, Anil K.; Pelletier, Dale A.; Moon, Ji Won; ...

2015-08-28

Size and shape distributions of nanoparticles can drastically contribute to the overall properties of nanoparticles, thereby influencing their interaction with different chemotherapeutic molecules, biological organisms and or materials and cell types. Therefore, to exploit the proper use of nanoparticles for various biomedical and biosensor applications, it is important to obtain well-separated monodispersed nanoparticles. However, gaining precise control over the morphological characteristics of nanoparticles during their synthesis is often a challenging task. Consequently, post-synthesis separation of nanoparticles is necessary. In the present study, we demonstrate the successful one-pot post-synthesis separation of anisotropic silver nanoparticles to near modispersities using sucrose density gradientmore » sedimentation. The separation of the nanoparticles was evidenced based on optical confirmation, and spectrophotometric and transmission electron microscopy measurements. Our results clearly demonstrate the facile separation of anisotropic silver nanoparticles using sucrose density gradient sedimentation and can enable the use of nanoparticles for various biomedical applications.« less

Size-separation of silver nanoparticles using sucrose gradient centrifugation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Suresh, Anil K.; Pelletier, Dale A.; Moon, Ji Won

Size and shape distributions of nanoparticles can drastically contribute to the overall properties of nanoparticles, thereby influencing their interaction with different chemotherapeutic molecules, biological organisms and or materials and cell types. Therefore, to exploit the proper use of nanoparticles for various biomedical and biosensor applications, it is important to obtain well-separated monodispersed nanoparticles. However, gaining precise control over the morphological characteristics of nanoparticles during their synthesis is often a challenging task. Consequently, post-synthesis separation of nanoparticles is necessary. In the present study, we demonstrate the successful one-pot post-synthesis separation of anisotropic silver nanoparticles to near modispersities using sucrose density gradientmore » sedimentation. The separation of the nanoparticles was evidenced based on optical confirmation, and spectrophotometric and transmission electron microscopy measurements. Our results clearly demonstrate the facile separation of anisotropic silver nanoparticles using sucrose density gradient sedimentation and can enable the use of nanoparticles for various biomedical applications.« less

Effects of xylitol as a sugar substitute on diabetes-related parameters in nondiabetic rats.

PubMed

Islam, Md Shahidul

2011-05-01

Abstract The present study was examined the effects of xylitol feeding on diabetes-associated parameters in nondiabetic rats. Seven-week-old male Sprague-Dawley rats were randomly divided into three groups: control (five rats), sucrose (six rats), and xylitol (six rats). Animal had free access to a commercial rat pellet diet, and ad libitum water, 10% sucrose solution, and 10% xylitol solution were supplied to the control, sucrose, and xylitol groups, respectively. After 3 weeks of feeding of experimental diets, food intakes were significantly (P<.05) lower in the sucrose and xylitol groups compared with the control group. Drink intake was significantly higher in the sucrose group but significantly lower in the xylitol group compared with the control group. Body weight gain was significantly lower in the xylitol group compared with the sucrose group. Weekly nonfasting blood glucose was significantly increased, but fasting blood glucose was significantly decreased, in the sucrose group compared with the control and xylitol groups. Significantly better glucose tolerance was observed in the xylitol group compared with the control and sucrose groups. Serum insulin and fructosamine concentrations were not significantly influenced by the feeding of xylitol or sucrose. Relative liver weight and liver glycogen were significantly increased in the xylitol group compared with the sucrose group, whereas no difference was observed between the xylitol and control groups. Serum total cholesterol and low-density lipoprotein-cholesterol were significantly decreased in the sucrose and xylitol groups, and serum triglyceride of the xylitol group, but not the sucrose group, was significantly increased compared with the control group. Data of this study suggest that xylitol can be a better sweetener than sucrose to maintain diabetes-related parameters at a physiologically safer and stable condition.

Face-by-face growth of sucrose crystals from aqueous solutions in the presence of raffinose—II: Growth morphology and segregation

NASA Astrophysics Data System (ADS)

Sgualdino, G.; Aquilano, D.; Pastero, L.; Vaccari, G.

2007-10-01

Raffinose segregation into sucrose crystals is experimentally determined along with the modifications of the quantitative sucrose growth morphology, which are in turn related to the different growth conditions. ( Craff, σ) morphodromes nicely represent the conflict between the supersaturation and the raffinose concentration in the solution on the growth morphology, while the overall segregation rate is nearly proportional to the linear overall crystal growth rate. Chernov and Burton-Prim-Slichter models, checked to fit our keff and ln(keff-1-1) coefficients as a function of the supersaturation and of the mean linear overall growth rate, do not allow to know whether the segregation occurs either by a process dominated by surface integration, or by additive transfer dominated by volume diffusion within the boundary layer. The distribution of segregated raffinose strictly depends on the { h k l} growth sectors and doped crystals contain deformed lattice zones, as it comes out from X-ray powder diagrams.

Improvement of fish freshness determination method by the application of amorphous freeze-dried enzymes.

PubMed

Srirangsan, Paveena; Hamada-Sato, Naoko; Kawai, Kiyoshi; Watanabe, Manabu; Suzuki, Toru

2010-12-08

Alkaline phosphatase (ALP), nucleoside phosphorylase (NP), and xanthine oxidase (XOD) were used in a colorimetric method for evaluation of fish freshness based on the Ki value. Two enzyme mixtures, NP-XOD and ALP-NP-XOD, were prepared with a color developing agent, and stabilities of the enzymes were improved by freeze-drying with glass-forming additives, i.e., sucrose and sucrose-gelatin. As a result, a linear relationship was obtained between the Ki values determined by the developed colorimetric method and a conventional high-performance liquid chromatography with a high correlation coefficient of 0.997. All enzyme samples containing the additive(s) were amorphous, and higher enzymes activities were maintained compared to those freeze-dried without an additive. Sucrose-gelatin/enzyme mixtures showed higher glass transition temperature; consequently, the enzymes were better stabilized than the sucrose/enzyme formulations. Using the sucrose-gelatin/enzyme mixture, Ki values of fish meat could be accurately determined even after 6-month storage of the dried enzymes at 40 °C.

Dextran synthesized by Leuconostoc mesenteroides BD1710 in tomato juice supplemented with sucrose.

PubMed

Han, Jin; Hang, Feng; Guo, Benheng; Liu, Zhenmin; You, Chunpin; Wu, Zhengjun

2014-11-04

The characteristics of the growth of Leuconostoc mesenteroides BD1710 and the synthesis of dextran in tomato juice supplemented with 15% sucrose were assayed. L. mesenteroides BD1710 could synthesize approximately 32 g L(-1) dextran in the tomato-juice-sucrose medium when cultured at 28 °C for 48 h, which was on the same level as the dextran yield in a chemically defined medium. The viscosity of the cultured tomato-juice-sucrose medium with various dextran contents was also measured. The results of the monosaccharide composition, molecular-weight distribution, Fourier transform infrared spectra (FTIR) and nuclear magnetic resonance spectra (NMR) showed that the polysaccharide synthesized by L. mesenteroides BD1710 in the tomato-juice-sucrose medium was dextran with a peak molecular weight of 6.35 × 10(5)Da, a linear backbone composed of consecutive α-(1 → 6)-linked d-glucopyranosyl units and approximately 6% α-(1 → 3) branches. Copyright © 2014 Elsevier Ltd. All rights reserved.

Supercoiled circular DNA of an insect granulosis virus

PubMed Central

Tweeten, Kathleen A.; Bulla, Lee A.; Consigli, Richard A.

1977-01-01

The DNA of the granulosis virus of the Indian meal moth, Plodia interpunctella, was characterized by physical chemical and electron microscopic techniques. Twenty-five percent of the DNA extracted from purified virus was isolated as supercoiled circular molecules. The remaining 75% consisted of relaxed circular molecules. These molecular forms were indicated by the production of two radioactive bands during sedimentation of 3H-labeled granulosis virus DNA in alkaline sucrose gradients or in equilibrium density gradients of neutral cesium chloride/propidium iodide. Electron microscopic visualization of the DNA that banded at the higher density in the latter gradients revealed supercoiled structures whereas that of DNA that banded at the lower density demonstrated relaxed circular molecules. The superhelical molecules were converted to relaxed circles by treatment with pancreatic DNase. The molecular weight of the viral DNA was calculated to be 81 × 106 by sedimentation in neutral sucrose and 78 × 106 by sedimentation in alkaline sucrose. The molecular weight estimated from length measurements in electron micrographs was 76 × 106. The buoyant density of the granulosis virus DNA was 1.703 g/cm3 and that of its insect host DNA was 1.697 g/cm3. Equilibrium sedimentation in cesium chloride and thermal denaturation indicated G + C contents of 44% and 39% for the viral and host DNA, respectively. Images PMID:198791

Supercoiled circular DNA of an insect granulosis virus.

PubMed

Tweeten, K A; Bulla, L A; Consigli, R A

1977-08-01

The DNA of the granulosis virus of the Indian meal moth, Plodia interpunctella, was characterized by physical chemical and electron microscopic techniques. Twenty-five percent of the DNA extracted from purified virus was isolated as supercoiled circular molecules. The remaining 75% consisted of relaxed circular molecules. These molecular forms were indicated by the production of two radioactive bands during sedimentation of (3)H-labeled granulosis virus DNA in alkaline sucrose gradients or in equilibrium density gradients of neutral cesium chloride/propidium iodide. Electron microscopic visualization of the DNA that banded at the higher density in the latter gradients revealed supercoiled structures whereas that of DNA that banded at the lower density demonstrated relaxed circular molecules. The superhelical molecules were converted to relaxed circles by treatment with pancreatic DNase. The molecular weight of the viral DNA was calculated to be 81 x 10(6) by sedimentation in neutral sucrose and 78 x 10(6) by sedimentation in alkaline sucrose. The molecular weight estimated from length measurements in electron micrographs was 76 x 10(6). The buoyant density of the granulosis virus DNA was 1.703 g/cm(3) and that of its insect host DNA was 1.697 g/cm(3). Equilibrium sedimentation in cesium chloride and thermal denaturation indicated G + C contents of 44% and 39% for the viral and host DNA, respectively.

Sequential injection system for simultaneous determination of sucrose and phosphate in cola drinks using paired emitter-detector diode sensor.

PubMed

Saetear, Phoonthawee; Khamtau, Kittiwut; Ratanawimarnwong, Nuanlaor; Sereenonchai, Kamonthip; Nacapricha, Duangjai

2013-10-15

This work presents the simultaneous determination of sucrose and phosphate by using sequential injection (SI) system with a low cost paired emitter-detector diode (PEDD) light sensor. The PEDD uses two 890 nm LEDs. Measurement of sucrose in Brix unit was carried out based on the detection of light refraction occurring at the liquid interface (the schlieren effect) between the sucrose solution and water. Phosphate was measured from the formation of calcium phosphate with turbidimetric detection. With careful design of the loading sequence and volume (sample--precipitating reagent--sample), simultaneous detection of sucrose and phosphate was accomplished with the single PEDD detector. At the optimized condition, linear calibrations from 1 to 7 Brix sucrose and from 50 to 200mg PO4(3-)L(-1) were obtained. Good precision at lower than 2% RSD (n=10) for both analytes with satisfactory throughput of 21 injections h(-1) was achieved. The method was successfully applied for the determination of sucrose and phosphate in cola drinks. The proposed method is readily applicable for automation and is found to be an alternative method to conventional procedures for on-line quality control process in cola drink industry. Crown Copyright © 2013. Published by Elsevier B.V. All rights reserved.

Honey promotes lower weight gain, adiposity, and triglycerides than sucrose in rats.

PubMed

Nemoseck, Tricia M; Carmody, Erin G; Furchner-Evanson, Allison; Gleason, Marsa; Li, Amy; Potter, Hayley; Rezende, Lauren M; Lane, Kelly J; Kern, Mark

2011-01-01

Various dietary carbohydrates have been linked to obesity and altered adipose metabolism; however, the influences of honey vs common sweeteners have not been fully explored. We hypothesized that in comparison with sucrose, a honey-based diet would promote lower weight gain, adiposity, and related biomarkers (leptin, insulin, and adiponectin) as well as a better blood lipid profile. Thirty-six male Sprague-Dawley rats (228.1 ± 12.5 g) were equally divided by weight into 2 groups (n = 18) and provided free access to 1 of 2 diets of equal energy densities differing only in a portion of the carbohydrate. Diets contained 20% carbohydrate (by weight of total diet) from either clover honey or sucrose. After 33 days, epididymal fat pads were excised and weighed, and blood was collected for analyses of serum concentrations of lipids, glucose, and markers of adiposity and inflammation. Body weight gain was 14.7% lower (P ≤ .05) for rats fed honey, corresponding to a 13.3% lower (P ≤ .05) consumption of food/energy, whereas food efficiency ratios were nearly identical. Epididymal fat weight was 20.1% lower (P ≤ .05) for rats fed honey. Serum concentrations of triglycerides and leptin were lower (P ≤ .05) by 29.6% and 21.6%, respectively, and non-high-density lipoprotein cholesterol was higher (P ≤ .05) by 16.8% for honey-fed rats. No significant differences in serum total cholesterol, high-density lipoprotein cholesterol, adiponectin, C-reactive protein, monocyte chemoattractant protein-1, glucose, or insulin were detected. These results suggest that in comparison with sucrose, honey may reduce weight gain and adiposity, presumably due to lower food intake, and promote lower serum triglycerides but higher non-high-density lipoprotein cholesterol concentrations. Copyright © 2011 Elsevier Inc. All rights reserved.

Lysis of Bacillus subtilis Cells by Glycerol and Sucrose Esters of Fatty Acids

PubMed Central

Tsuchido, Tetsuaki; Ahn, Yung-Hoon; Takano, Mitsuo

1987-01-01

The lytic action of glycerol and sucrose esters of fatty acids with different carbon chain lengths on the exponentially growing cells of Bacillus subtilis 168 was investigated. Of each series of esters, glycerol dodecanoate and sucrose hexadecanoate were the most active. Lysis at 1 h after the addition of 0.1 mM glycerol dodecanoate or 20 μg of sucrose hexadecanoate per ml was 81 or 79%, respectively, as evaluated by the reduction in optical density. During this treatment a great loss of viability occurred that preceded lysis. The results that were obtained suggest that autolysis is induced by these esters. The esters caused morphological changes in the cells, but a seeming adaptation of the cells to esters was seen. Images PMID:16347300

A novel ultra performance liquid chromatography-tandem mass spectrometry method for the determination of sucrose octasulfate in dog plasma.

PubMed

Ke, Yuyong; Li, Steve Lianghong; Chang, Linda Dongxia; Kapanadze, Theo

2015-01-26

A novel, specific and sensitive bioanalytical method has been developed for the determination of sucrose octasulfate (SOS) in dog plasma and urine using ion-pair reversed-phase ultraperformance liquid chromatography coupled with electrospray triple quadruple mass spectrometry (IPRP-UPLC ESI MS/MS). (13)C-labeled sucrose octasulfate-(13)C12 sodium salt is used as the internal standard. 200 μL of plasma or serum sample is extracted using weak anion exchange solid phase cartridge. In this method, a polar amide column is employed for the liquid chromatograph (LC) separation while the diethylamine and formic acid buffer is used as the ion-pairing reagent. The low limitation of quantitation of sucrose octasulfate is 0.20 ng on the column with a signal to noise ratio larger than 50. Parameters such as linearity, accuracy and precision have been validated in full compliance with the FDA guidelines for the bioanalytical method development and validation. A linear regression model fit the calibration curve very well with R>0.99. The bias and coefficient of variation of all levels of QCs are within the range of 15%. The selectivity, matrix effect and stabilities of analytes in solution and matrix have also been evaluated and the results met the acceptance criteria according to the guidelines. Based on these results, the method has qualified to analyze sucrose octasulfate in dog plasma for clinic research. This method has been applied to 1000 preclinical samples. Copyright © 2014 Elsevier B.V. All rights reserved.

THE SEDIMENTATION PROPERTIES OF THE SKIN-SENSITIZING ANTIBODIES OF RAGWEED-SENSITIVE PATIENTS

PubMed Central

Andersen, Burton R.; Vannier, Wilton E.

1964-01-01

The sedimentation coefficients of the skin-sensitizing antibodies to ragweed were evaluated by the moving partition cell method and the sucrose density gradient method. The most reliable results were obtained by sucrose density gradient ultracentrifugation which showed that the major portion of skin-sensitizing antibodies to ragweed sediment with an average value of 7.7S (7.4 to 7.9S). This is about one S unit faster than γ-globulins (6.8S). The data from the moving partition cell method are in agreement with these results. Our studies failed to demonstrate heterogeneity of the skin-sensitizing antibodies with regard to sedimentation rate. PMID:14194391

Measuring the Density of a Sugar Solution: A General Chemistry Experiment Using a Student-Prepared Unknown

ERIC Educational Resources Information Center

Peterson, Karen I.

2008-01-01

The experiment developed in this article addresses the concept of equipment calibration for reducing systematic error. It also suggests simple student-prepared sucrose solutions for which accurate densities are known, but not readily available to students. Densities are measured with simple glassware that has been calibrated using the density of…

Kernel abortion in maize : I. Carbohydrate concentration patterns and Acid invertase activity of maize kernels induced to abort in vitro.

PubMed

Hanft, J M; Jones, R J

1986-06-01

Kernels cultured in vitro were induced to abort by high temperature (35 degrees C) and by culturing six kernels/cob piece. Aborting kernels failed to enter a linear phase of dry mass accumulation and had a final mass that was less than 6% of nonaborting field-grown kernels. Kernels induced to abort by high temperature failed to synthesize starch in the endosperm and had elevated sucrose concentrations and low fructose and glucose concentrations in the pedicel during early growth compared to nonaborting kernels. Kernels induced to abort by high temperature also had much lower pedicel soluble acid invertase activities than did nonaborting kernels. These results suggest that high temperature during the lag phase of kernel growth may impair the process of sucrose unloading in the pedicel by indirectly inhibiting soluble acid invertase activity and prevent starch synthesis in the endosperm. Kernels induced to abort by culturing six kernels/cob piece had reduced pedicel fructose, glucose, and sucrose concentrations compared to kernels from field-grown ears. These aborting kernels also had a lower pedicel soluble acid invertase activity compared to nonaborting kernels from the same cob piece and from field-grown ears. The low invertase activity in pedicel tissue of the aborting kernels was probably caused by a lack of substrate (sucrose) for the invertase to cleave due to the intense competition for available assimilates. In contrast to kernels cultured at 35 degrees C, aborting kernels from cob pieces containing all six kernels accumulated starch in a linear fashion. These results indicate that kernels cultured six/cob piece abort because of an inadequate supply of sugar and are similar to apical kernels from field-grown ears that often abort prior to the onset of linear growth.

Kernel Abortion in Maize 1

PubMed Central

Hanft, Jonathan M.; Jones, Robert J.

1986-01-01

Kernels cultured in vitro were induced to abort by high temperature (35°C) and by culturing six kernels/cob piece. Aborting kernels failed to enter a linear phase of dry mass accumulation and had a final mass that was less than 6% of nonaborting field-grown kernels. Kernels induced to abort by high temperature failed to synthesize starch in the endosperm and had elevated sucrose concentrations and low fructose and glucose concentrations in the pedicel during early growth compared to nonaborting kernels. Kernels induced to abort by high temperature also had much lower pedicel soluble acid invertase activities than did nonaborting kernels. These results suggest that high temperature during the lag phase of kernel growth may impair the process of sucrose unloading in the pedicel by indirectly inhibiting soluble acid invertase activity and prevent starch synthesis in the endosperm. Kernels induced to abort by culturing six kernels/cob piece had reduced pedicel fructose, glucose, and sucrose concentrations compared to kernels from field-grown ears. These aborting kernels also had a lower pedicel soluble acid invertase activity compared to nonaborting kernels from the same cob piece and from field-grown ears. The low invertase activity in pedicel tissue of the aborting kernels was probably caused by a lack of substrate (sucrose) for the invertase to cleave due to the intense competition for available assimilates. In contrast to kernels cultured at 35°C, aborting kernels from cob pieces containing all six kernels accumulated starch in a linear fashion. These results indicate that kernels cultured six/cob piece abort because of an inadequate supply of sugar and are similar to apical kernels from field-grown ears that often abort prior to the onset of linear growth. PMID:16664846

Switching the mode of sucrose utilization by Saccharomyces cerevisiae

PubMed Central

Badotti, Fernanda; Dário, Marcelo G; Alves, Sergio L; Cordioli, Maria Luiza A; Miletti, Luiz C; de Araujo, Pedro S; Stambuk, Boris U

2008-01-01

Background Overflow metabolism is an undesirable characteristic of aerobic cultures of Saccharomyces cerevisiae during biomass-directed processes. It results from elevated sugar consumption rates that cause a high substrate conversion to ethanol and other bi-products, severely affecting cell physiology, bioprocess performance, and biomass yields. Fed-batch culture, where sucrose consumption rates are controlled by the external addition of sugar aiming at its low concentrations in the fermentor, is the classical bioprocessing alternative to prevent sugar fermentation by yeasts. However, fed-batch fermentations present drawbacks that could be overcome by simpler batch cultures at relatively high (e.g. 20 g/L) initial sugar concentrations. In this study, a S. cerevisiae strain lacking invertase activity was engineered to transport sucrose into the cells through a low-affinity and low-capacity sucrose-H+ symport activity, and the growth kinetics and biomass yields on sucrose analyzed using simple batch cultures. Results We have deleted from the genome of a S. cerevisiae strain lacking invertase the high-affinity sucrose-H+ symporter encoded by the AGT1 gene. This strain could still grow efficiently on sucrose due to a low-affinity and low-capacity sucrose-H+ symport activity mediated by the MALx1 maltose permeases, and its further intracellular hydrolysis by cytoplasmic maltases. Although sucrose consumption by this engineered yeast strain was slower than with the parental yeast strain, the cells grew efficiently on sucrose due to an increased respiration of the carbon source. Consequently, this engineered yeast strain produced less ethanol and 1.5 to 2 times more biomass when cultivated in simple batch mode using 20 g/L sucrose as the carbon source. Conclusion Higher cell densities during batch cultures on 20 g/L sucrose were achieved by using a S. cerevisiae strain engineered in the sucrose uptake system. Such result was accomplished by effectively reducing sucrose uptake by the yeast cells, avoiding overflow metabolism, with the concomitant reduction in ethanol production. The use of this modified yeast strain in simpler batch culture mode can be a viable option to more complicated traditional sucrose-limited fed-batch cultures for biomass-directed processes of S. cerevisiae. PMID:18304329

Switching the mode of sucrose utilization by Saccharomyces cerevisiae.

PubMed

Badotti, Fernanda; Dário, Marcelo G; Alves, Sergio L; Cordioli, Maria Luiza A; Miletti, Luiz C; de Araujo, Pedro S; Stambuk, Boris U

2008-02-27

Overflow metabolism is an undesirable characteristic of aerobic cultures of Saccharomyces cerevisiae during biomass-directed processes. It results from elevated sugar consumption rates that cause a high substrate conversion to ethanol and other bi-products, severely affecting cell physiology, bioprocess performance, and biomass yields. Fed-batch culture, where sucrose consumption rates are controlled by the external addition of sugar aiming at its low concentrations in the fermentor, is the classical bioprocessing alternative to prevent sugar fermentation by yeasts. However, fed-batch fermentations present drawbacks that could be overcome by simpler batch cultures at relatively high (e.g. 20 g/L) initial sugar concentrations. In this study, a S. cerevisiae strain lacking invertase activity was engineered to transport sucrose into the cells through a low-affinity and low-capacity sucrose-H+ symport activity, and the growth kinetics and biomass yields on sucrose analyzed using simple batch cultures. We have deleted from the genome of a S. cerevisiae strain lacking invertase the high-affinity sucrose-H+ symporter encoded by the AGT1 gene. This strain could still grow efficiently on sucrose due to a low-affinity and low-capacity sucrose-H+ symport activity mediated by the MALx1 maltose permeases, and its further intracellular hydrolysis by cytoplasmic maltases. Although sucrose consumption by this engineered yeast strain was slower than with the parental yeast strain, the cells grew efficiently on sucrose due to an increased respiration of the carbon source. Consequently, this engineered yeast strain produced less ethanol and 1.5 to 2 times more biomass when cultivated in simple batch mode using 20 g/L sucrose as the carbon source. Higher cell densities during batch cultures on 20 g/L sucrose were achieved by using a S. cerevisiae strain engineered in the sucrose uptake system. Such result was accomplished by effectively reducing sucrose uptake by the yeast cells, avoiding overflow metabolism, with the concomitant reduction in ethanol production. The use of this modified yeast strain in simpler batch culture mode can be a viable option to more complicated traditional sucrose-limited fed-batch cultures for biomass-directed processes of S. cerevisiae.

Avocado oil supplementation modifies cardiovascular risk profile markers in a rat model of sucrose-induced metabolic changes.

PubMed

Carvajal-Zarrabal, Octavio; Nolasco-Hipolito, Cirilo; Aguilar-Uscanga, M Guadalupe; Melo-Santiesteban, Guadalupe; Hayward-Jones, Patricia M; Barradas-Dermitz, Dulce M

2014-01-01

The purpose of this study was to evaluate the effects of avocado oil administration on biochemical markers of cardiovascular risk profile in rats with metabolic changes induced by sucrose ingestion. Twenty-five rats were divided into five groups: a control group (CG; basic diet), a sick group (MC; basic diet plus 30% sucrose solution), and three other groups (MCao, MCac, and MCas; basic diet plus 30% sucrose solution plus olive oil and avocado oil extracted by centrifugation or using solvent, resp.). Glucose, total cholesterol, triglycerides, phospholipids, low- and high-density lipoproteins (LDL, HDL), very low-density lipoprotein (VLDL), lactic dehydrogenase, creatine kinase, and high sensitivity C-reactive protein concentration were analyzed. Avocado oil reduces TG, VLDL, and LDL levels, in the LDL case significantly so, without affecting HDL levels. An effect was exhibited by avocado oil similar to olive oil, with no significant difference between avocado oil extracted either by centrifugation or solvent in myocardial injury biochemical indicators. Avocado oil decreased hs-CRP levels, indicating that inflammatory processes were partially reversed. These findings suggested that avocado oil supplementation has a positive health outcome because it reduces inflammatory events and produces positive changes in the biochemical indicators studied, related to the development of metabolic syndrome.

Cariogenicity features of Streptococcus mutans in presence of rubusoside.

PubMed

Chu, Jinpu; Zhang, Tieting; He, Kexin

2016-05-11

One promising way of reducing caries is by using sucrose substitutes in food. rubusoside is a prototype sweet substance isolated from the leaves of the plant Rubrus suavissimus S. Lee. (Rosaceae), and is rated sweeter than sucrose. The purpose of this study was to investigate the effects of rubusoside on Streptococcus mutans growth, acidogenicity, and adherence to glass in vitro. The effects of rubusoside on the growth and glass surface adhering of Streptococcus mutans were investigated by measuring the optical density of the culture at 540 nm with a spectrophotometer. Rubusoside influence on Streptococcus mutans acidogenicity was determined by measuring the pH of the culture. Sucrose, glucose, maltose, fructose and xylitol were designed to compare with rubusoside. S. mutans growth in the rubusoside-treated group was significantly lower than that in the sucrose, glucose, maltose and fructose groups (p < 0.05) except for xylitol group (p > 0.05). Sucrose-treated S. mutans exhibited the highest adherence to glass, and rubusoside-treated S. mutans exhibited the lowest. S. mutans adherence to a glass surface and acidogenicity with sucrose were significantly reduced by rubusoside. Rubusoside may have some potential as a non-cariogenic, non-caloric sweetener.

Hyperphagia induced by sucrose: relation to circulating and CSF glucose and corticosterone and orexigenic peptides in the arcuate nucleus.

PubMed

Gaysinskaya, V A; Karatayev, O; Shuluk, J; Leibowitz, S F

2011-01-01

Sucrose-rich diets compared to starch-rich diets are known to stimulate overeating under chronic conditions. The present study in normal-weight rats established an acute "preload-to-test meal" paradigm for demonstrating sucrose-induced hyperphagia and investigating possible mechanisms that mediate this behavioral phenomenon. In this acute paradigm, the rats were first given a small (15 kcal) sucrose preload (30% sucrose) for 30 min compared to an equicaloric, starch preload (25% starch with 5% sucrose) and then allowed to freely consume a subsequent test meal of lab chow. The sucrose preload, when compared to a starch preload equal in energy density and palatability, consistently increased food intake in the subsequent test meal occurring between 60 and 120 min after the end of the preload. Measurements of hormones, metabolites and hypothalamic peptides immediately preceding this hyperphagia revealed marked differences between the sucrose vs starch groups that could contribute to the increase in food intake. Whereas the sucrose group compared to the starch group immediately after the preload (at 10 min) had elevated levels of glucose in serum and cerebrospinal fluid (CSF) along with reduced expressions of neuropeptide Y (NPY) and agouti-related protein (AgRP) in the arcuate nucleus (ARC), the subsequent effects (at 30-60 min) just preceding the test meal hyperphagia were the reverse. Along with lower levels of glucose, they included markedly elevated serum and CSF levels of corticosterone and mRNA levels of NPY and AgRP in the ARC. In addition to establishing an animal model for sucrose-induced hyperphagia, these results demonstrate peripheral and central mechanisms that may mediate this behavioral phenomenon. Copyright © 2010 Elsevier Inc. All rights reserved.

HYPERPHAGIA INDUCED BY SUCROSE: RELATION TO CIRCULATING AND CSF GLUCOSE AND CORTICOSTERONE AND OREXIGENIC PEPTIDES IN THE ARCUATE NUCLEUS

PubMed Central

Gaysinskaya, V. A.; Karatayev, O.; Shuluk, J.; Leibowitz, S. F.

2010-01-01

Sucrose-rich diets compared to starch-rich diets are known to stimulate overeating under chronic conditions. The present study in normal-weight rats established an acute “preload-to-test meal” paradigm for demonstrating sucrose-induced hyperphagia and investigating possible mechanisms that mediate this behavioral phenomenon. In this acute paradigm, the rats were first given a small (15 kcals) sucrose preload (30% sucrose) for 30 min compared to an equicaloric, starch preload (25% starch with 5% sucrose) and then allowed to freely consume a subsequent test meal of lab chow. The sucrose preload, when compared to a starch preload equal in energy density and palatability, consistently increased food intake in the subsequent test meal occurring between 60–120 min after the end of the preload. Measurements of hormones, metabolites and hypothalamic peptides immediately preceding this hyperphagia revealed marked differences between the sucrose vs starch groups that could contribute to the increase in food intake. Whereas the sucrose group compared to starch group immediately after the preload (at 10 min) had elevated levels of glucose in serum and cerebrospinal fluid (CSF) along with reduced expression of neuropeptide Y (NPY) and agouti-related protein (AgRP) in the arcuate nucleus (ARC), the subsequent effects (at 30–60 min) just preceding the test meal hyperphagia were the reverse. Along with lower levels of glucose, they included markedly elevated serum and CSF levels of corticosterone and mRNA levels of NPY and AgRP in the ARC. In addition to establishing an animal model for sucrose-induced hyperphagia, these results demonstrate peripheral and central mechanisms that may mediate this behavioral phenomenon. PMID:21036188

Baclofen-induced reductions in optional food intake depend upon food composition.

PubMed

Wojnicki, F H E; Charny, G; Corwin, R L W

2013-05-01

Baclofen reduces intake of some foods but stimulates intake or has no effect on others. The reasons for these differences are not known. The present study examined effects of baclofen when composition, energy density, preference, presentation and intake of optional foods varied. Semi-solid fat emulsions and sucrose products were presented for brief periods to non-food-deprived rats. In Experiment 1, fat and sucrose composition were varied while controlling energy density. In Experiment 2A, schedule of access and the number of optional foods were varied. In Experiment 2B, the biopolymer (thickener) was examined. Baclofen reduced intake of fat and/or sugar options with different energy densities (1.28-9kcal/g), when presented daily or intermittently, and when intakes were relatively high or low. However, the efficacy of baclofen was affected by the biopolymer used to thicken the options: baclofen had no effect when options were thickened with one biopolymer (3173), but reduced intake when options were thickened with another biopolymer (515). Baclofen failed to reduce intake of a concentrated sugar option (64% sucrose), regardless of biopolymer. Based upon these results, caution is urged when interpreting results obtained with products using different thickening agents. Systematic research is needed when designing products used in rat models of food intake. Copyright © 2013 Elsevier Ltd. All rights reserved.

BACLOFEN-INDUCED REDUCTIONS IN OPTIONAL FOOD INTAKE DEPEND UPON FOOD COMPOSITION

PubMed Central

Wojnicki, F.H.E.; Charny, G.; Corwin, R.L.W

2013-01-01

Baclofen reduces intake of some foods but stimulates intake or has no effect on others. The reasons for these differences are not known. The present study examined effects of baclofen when composition, energy density, preference, presentation and intake of optional foods varied. Semi-solid fat emulsions and sucrose products were presented for brief periods to non-food-deprived rats. In Experiment 1, fat and sucrose composition were varied while controlling energy density. In Experiment 2A, schedule of access and the number of optional foods were varied. In Experiment 2B, the biopolymer (thickener) was examined. Baclofen reduced intake of fat and/or sugar options with different energy densities (1.28-9 kcal/g), when presented daily or intermittently, and when intakes were relatively high or low. However, the efficacy of baclofen was affected by the biopolymer used to thicken the options: baclofen had no effect when options were thickened with one biopolymer (3173), but reduced intake when options were thickened with another biopolymer (515). Baclofen failed to reduce intake of a concentrated sugar option (64% sucrose), regardless of biopolymer. Based upon these results, caution is urged when interpreting results obtained with products using different thickening agents. Systematic research is needed when designing products used in rat models of food intake. PMID:23321345

Effect of Environmental Density and Buoyancy on Growth and Gravitropic Response in Maize Roots

NASA Astrophysics Data System (ADS)

Robbins, J. L.; Mulkey, T. J.

2008-06-01

The mechanism by which plants sense gravity is not fully understood. The hydrostatic model was proposed as an alternative to the statolith model. These experiments are designed to provide further understanding about the underlying mechanism of the gravitropic sensing. Primary roots of maize with a length of about 1 cm were used. The roots were placed in environments of various density and buoyancy using air, water, sucrose, sucrose/polyethylene glycol 4000 (PEG), PEG 8000, and Ficoll PM 400. The rates of growth and gravitropic curvature were monitored using time-lapse video and digital recordings. Comparison of roots in air to roots in oxygenated water indicate that there is no significant difference in growth rates but the higher density of water and the other test solutions significantly slows the gravitropic response. Altering the environmental density and buoyancy of the solution surrounding the root does not appear to alter sedimentation of statoliths within the root tip.

Characterization of the Leptospiral Outer Membrane and Description of Three Novel Leptospiral Membrane Proteins

PubMed Central

Haake, David A.; Matsunaga, James

2002-01-01

The outer membrane (OM) of the mammalian pathogen Leptospira kirschneri was isolated in the form of membrane vesicles by alkaline plasmolysis and separated from the protoplasmic cylinder by sucrose density gradient ultracentrifugation. All four components of the alkaline plasmolysis buffer, including 1.0 M NaCl, 27% sucrose (wt/vol), 2 mM EDTA, and 10 mM Tris (pH 9), were required for efficient OM release, as judged by recovery of leptospiral lipopolysaccharide. Two populations of OM vesicles (OMVs) were recovered, with peak concentrations found in the sucrose gradient at densities of 1.16 and 1.18 g/ml. Transmission electron microscopy revealed that the more buoyant OMV population was smaller (<0.1 μm in diameter) than the denser OMV population (0.2 to 0.3 μm in diameter). The densities of both populations of OMVs were distinct from that of the protoplasmic-cylinder material, which was found in the sucrose gradient at a density of 1.20 g/ml. The OMV fractions were free of protoplasmic-cylinder material, as judged by immunoblotting with antibodies to the endoflagellar sheath protein, heat shock protein GroEL, and two novel cytoplasmic membrane proteins, lipoprotein LipL31 and transmembrane protein ImpL63. The protein components of the OMVs were characterized by one- and two-dimensional immunoblotting and found to include previously described OM proteins (OMPs), including the porin OmpL1; the lipoproteins LipL32, LipL36, and LipL41; and the peripheral membrane protein P31LipL45. A number of less well-characterized OMPs were also identified, including those with molecular masses of 16, 21, 21.5, 22, 31, 36, 44, 48, 90, and 116 kDa. The 48-kDa OMP was identified as a novel OM lipoprotein designated LipL48. The use of membrane-specific markers in OM isolation techniques facilitates an accurate description of the leptospiral OM and its components. PMID:12183539

A plasma membrane sucrose-binding protein that mediates sucrose uptake shares structural and sequence similarity with seed storage proteins but remains functionally distinct.

PubMed

Overvoorde, P J; Chao, W S; Grimes, H D

1997-06-20

Photoaffinity labeling of a soybean cotyledon membrane fraction identified a sucrose-binding protein (SBP). Subsequent studies have shown that the SBP is a unique plasma membrane protein that mediates the linear uptake of sucrose in the presence of up to 30 mM external sucrose when ectopically expressed in yeast. Analysis of the SBP-deduced amino acid sequence indicates it lacks sequence similarity with other known transport proteins. Data presented here, however, indicate that the SBP shares significant sequence and structural homology with the vicilin-like seed storage proteins that organize into homotrimers. These similarities include a repeated sequence that forms the basis of the reiterated domain structure characteristic of the vicilin-like protein family. In addition, analytical ultracentrifugation and nonreducing SDS-polyacrylamide gel electrophoresis demonstrate that the SBP appears to be organized into oligomeric complexes with a Mr indicative of the existence of SBP homotrimers and homodimers. The structural similarity shared by the SBP and vicilin-like proteins provides a novel framework to explore the mechanistic basis of SBP-mediated sucrose uptake. Expression of the maize Glb protein (a vicilin-like protein closely related to the SBP) in yeast demonstrates that a closely related vicilin-like protein is unable to mediate sucrose uptake. Thus, despite sequence and structural similarities shared by the SBP and the vicilin-like protein family, the SBP is functionally divergent from other members of this group.

Episodic sucrose intake during food restriction increases synaptic abundance of AMPA receptors in nucleus accumbens and augments intake of sucrose following restoration of ad libitum feeding.

PubMed

Peng, X-X; Lister, A; Rabinowitsch, A; Kolaric, R; Cabeza de Vaca, S; Ziff, E B; Carr, K D

2015-06-04

Weight-loss dieting often leads to loss of control, rebound weight gain, and is a risk factor for binge pathology. Based on findings that food restriction (FR) upregulates sucrose-induced trafficking of glutamatergic AMPA receptors to the nucleus accumbens (NAc) postsynaptic density (PSD), this study was an initial test of the hypothesis that episodic "breakthrough" intake of forbidden food during dieting interacts with upregulated mechanisms of synaptic plasticity to increase reward-driven feeding. Ad libitum (AL) fed and FR subjects consumed a limited amount of 10% sucrose, or had access to water, every other day for 10 occasions. Beginning three weeks after return of FR rats to AL feeding, when 24-h chow intake and rate of body weight gain had normalized, subjects with a history of sucrose intake during FR consumed more sucrose during a four week intermittent access protocol than the two AL groups and the group that had access to water during FR. In an experiment that substituted noncontingent administration of d-amphetamine for sucrose, FR subjects displayed an enhanced locomotor response during active FR but a blunted response, relative to AL subjects, during recovery from FR. This result suggests that the enduring increase in sucrose consumption is unlikely to be explained by residual enhancing effects of FR on dopamine signaling. In a biochemical experiment which paralleled the sucrose behavioral experiment, rats with a history of sucrose intake during FR displayed increased abundance of pSer845-GluA1, GluA2, and GluA3 in the NAc PSD relative to rats with a history of FR without sucrose access and rats that had been AL throughout, whether they had a history of episodic sucrose intake or not. A history of FR, with or without a history of sucrose intake, was associated with increased abundance of GluA1. A terminal 15-min bout of sucrose intake produced a further increase in pSer845-GluA1 and GluA2 in subjects with a history of sucrose intake during FR. Generally, neither a history of sucrose intake nor a terminal bout of sucrose intake affected AMPA receptor abundance in the NAc PSD of AL subjects. Together, these results are consistent with the hypothesis, but the functional contribution of increased synaptic incorporation of AMPA receptors remains to be established. Copyright © 2015 IBRO. Published by Elsevier Ltd. All rights reserved.

Application of diffusion ordered-1H-nuclear magnetic resonance spectroscopy to quantify sucrose in beverages.

PubMed

Cao, Ruge; Nonaka, Airi; Komura, Fusae; Matsui, Toshiro

2015-03-15

This work focuses on a quantitative analysis of sucrose using diffusion ordered-quantitative (1)H-nuclear magnetic resonance spectroscopy (DOSY-qNMR), where an analyte can be isolated from interference based on its characteristic diffusion coefficient (D) in gradient magnetic fields. The D value of sucrose in deuterium oxide at 30°C was 4.9 × 10(-10)m(2)/s at field gradient pulse from 5.0 × 10(-2) to 3.0 × 10(-1)T/m, separated from other carbohydrates (glucose and fructose). Good linearity (r(2)=0.9999) was obtained between sucrose (0.5-20.0 g/L) and the resonance area of target glucopyranosyl-α-C1 proton normalised to that of cellobiose C1 proton (100.0 g/L, as an internal standard) in 1D sliced DOSY spectrum. The DOSY-qNMR method was successfully applied to quantify sucrose in orange juice (36.1 ± 0.5 g/L), pineapple juice (53.5 ± 1.1g/L) and a sports drink (24.7 ± 0.6g/L), in good agreement with the results obtained by an F-kit method. Copyright © 2014 Elsevier Ltd. All rights reserved.

Determination of Sucrose in Honey with Derivatization/Solid-Phase Microextraction and Gas-Chromatography/Mass Spectrometry.

PubMed

Wang, Haijing; Geppert, Helmut; Fischer, Thomas; Wieprecht, Wolfgang; Möller, Detlev

2015-10-01

A new method for the determination of sucrose in honey with derivatization solid-phase microextraction and gas chromatography/mass spectrometry (D-SPME-GC/MS) was developed. The method incorporates a sample derivatization with acetic anhydride using N-methylimidazole as the catalyst and the subsequent enrichment of the analyte in a Polyacrylate-SPME fiber. Results show that 100 µL N-methylimidazole and 800 µL acetic anhydride were sufficient to complete the acetylation for sucrose in 100 µL aqueous sample at room temperature. For SPME, an enrichment time of 30 min was sufficient. SPME was performed by immersing the fiber into the solution with additional vibration. Then, the analyte was desorbed for 5 min at 280°C in the GC/MS injection port with splitless mode. The present method exhibits good linearity at a concentration range of 0.3-8% of sucrose in honey with excellent regression (R = 0.9993). The method has been successfully applied to the control of sucrose adulteration in honey. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Heat shock protein-containing exosomes in mid-trimester amniotic fluids.

PubMed

Asea, Alexzander; Jean-Pierre, Claudel; Kaur, Punit; Rao, Preethi; Linhares, Iara M; Skupski, Daniel; Witkin, Steven S

2008-10-01

Exosomes are multivesicular bodies formed by inverse membrane budding into the lumen of an endocytic compartment. Fusion with the plasma membrane leads to their release into the external milieu. The incorporation of heat shock proteins into exosomes has been associated with immune regulatory activity. We have examined whether heat shock protein-containing exosomes are present in mid-trimester amniotic fluid. Exosomes were isolated from mid-trimester amniotic fluids by sequential low-speed and high-speed centrifugation followed by sucrose density gradient centrifugation. Biochemical characterization included floatation pattern in sucrose gradients, acetylcholinesterase (AChE) activity and Western blot analysis for exosome-containing proteins. Exosomes were present in each of 23 amniotic fluids tested. They banded at a density of 1.17g/ml in sucrose gradients, were positive for AChE activity and contained tubulin, the inducible 72kDa heat shock protein, Hsp72 and the constitutively expressed heat shock protein, Hsc73; they were negative for calnexin. Exosome concentrations correlated positively with the number of pregnancies. Heat shock protein-containing exosomes are constituents of mid-trimester amniotic fluids and may contribute to immune regulation within the amniotic cavity.

Subcellular distribution of gluconeogenetic enzymes in germinating castor bean endosperm

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nishimura, M.; Beevers, H.

1979-07-01

The intracellular distribution of enzymes capable of catalyzing the reactions from oxaloacetate to sucrose in germinating castor bean endosperm has been studied by sucrose density gradient centrifugation. One set of glycolytic enzyme activities was detected in the plastids and another in the cytosol. The percentages of their activities in the plastids were less than 10% of total activities except for aldolase and fructose diphosphatase. The activities of several of the enzymes present in the plastids seem to be too low to account for the in vivo rate of gluconeogenesis whereas those in the cytosol are quite adequate. Furthermore, phosphoenolypyruvate carboxykinase,more » sucrose phosphate synthetase, and sucrose synthetase, which catalyze the first and final steps in the conversion of oxaloacetate to sucrose, were found only in the cytosol. It is deduced that in germinating castor bean endosperm the complete conversion of oxaloacetate to sucrose and CO/sub 2/ occurs in the cytosol. The plastids contain some enzymes of the pentose phosphate pathway, pyruvate dehydrogenase and fatty acid synthetase in addition to the set of glycolytic enzymes. This suggests that the role of the plastid in the endosperm of germinating castor bean is the production of fatty acids from sugar phosphates, as it is known to be in the endosperm during seed development.« less

Quantitative monitoring of sucrose, reducing sugar and total sugar dynamics for phenotyping of water-deficit stress tolerance in rice through spectroscopy and chemometrics

NASA Astrophysics Data System (ADS)

Das, Bappa; Sahoo, Rabi N.; Pargal, Sourabh; Krishna, Gopal; Verma, Rakesh; Chinnusamy, Viswanathan; Sehgal, Vinay K.; Gupta, Vinod K.; Dash, Sushanta K.; Swain, Padmini

2018-03-01

In the present investigation, the changes in sucrose, reducing and total sugar content due to water-deficit stress in rice leaves were modeled using visible, near infrared (VNIR) and shortwave infrared (SWIR) spectroscopy. The objectives of the study were to identify the best vegetation indices and suitable multivariate technique based on precise analysis of hyperspectral data (350 to 2500 nm) and sucrose, reducing sugar and total sugar content measured at different stress levels from 16 different rice genotypes. Spectral data analysis was done to identify suitable spectral indices and models for sucrose estimation. Novel spectral indices in near infrared (NIR) range viz. ratio spectral index (RSI) and normalised difference spectral indices (NDSI) sensitive to sucrose, reducing sugar and total sugar content were identified which were subsequently calibrated and validated. The RSI and NDSI models had R2 values of 0.65, 0.71 and 0.67; RPD values of 1.68, 1.95 and 1.66 for sucrose, reducing sugar and total sugar, respectively for validation dataset. Different multivariate spectral models such as artificial neural network (ANN), multivariate adaptive regression splines (MARS), multiple linear regression (MLR), partial least square regression (PLSR), random forest regression (RFR) and support vector machine regression (SVMR) were also evaluated. The best performing multivariate models for sucrose, reducing sugars and total sugars were found to be, MARS, ANN and MARS, respectively with respect to RPD values of 2.08, 2.44, and 1.93. Results indicated that VNIR and SWIR spectroscopy combined with multivariate calibration can be used as a reliable alternative to conventional methods for measurement of sucrose, reducing sugars and total sugars of rice under water-deficit stress as this technique is fast, economic, and noninvasive.

Effects of carbon amendment on in situ atrazine degradation and total microbial biomass.

PubMed

Ngigi, Anastasiah N; Getenga, Zachary M; Dörfler, Ulrike; Boga, Hamadi I; Kuria, Benson; Ndalut, Paul; Schroll, Reiner

2013-01-01

This study elucidates the effects of carbon amendment on metabolic degradation of atrazine (6-chloro-N(2)-ethyl-N(4)-isopropyl-1,3,5-triazine-2,4-diamine) and total microbial biomass in soil. Degradation of (14)C-ring-labelled atrazine was monitored in laboratory incubations of soils supplemented with 0, 10, 100 and 1000 μg g(-1) sucrose concentrations. An experiment to determine the effect of carbon amendment on total microbial biomass and soil respiration was carried out with different concentrations of sucrose and non-labelled atrazine. The soils were incubated at a constant temperature and constant soil moisture at water potential of -15 kPa and a soil density of 1.3 g cm(-3). Mineralization of (14)C-ring-labelled atrazine was monitored continuously over a period of 59 d in the first experiment. The CO(2) production was monitored for 62 d in the second experiment and microbial biomass determined at the end of the incubation period. The addition of 1000 μg g(-1) sucrose reduced atrazine mineralization to 43.5% compared to 51.7% of the applied amount for the treatment without sucrose. The addition of 1000 μg g(-1) sucrose modified the transformation products to 1.08 μg g(-1) deisopropylatrazine (DIA), 0.32 μg g(-1) desethylatrazine (DEA) and 0.18 μg g(-1) deisopropyl-2-hydroxyatrazine (OH-DIA). Treatment without sucrose resulted in formation of 0.64 μg g(-1) hydroxyatrazine (HA), 0.28 μg g(-1) DIA and 0.20 μg g(-1) OH-DIA. Atrazine dealkylation was enhanced in treatments with 100 and 1000 μg g(-1) of sucrose added. HA metabolite was formed in the control (no sucrose) and in the presence of 10 μg g(-1) of sucrose, whereas DEA was only detected in treatment with 1000 μg g(-1) sucrose. Results indicate that total microbial biomass increased significantly (P < 0.001) with the addition of 1000 μg g(-1) sucrose.

High-sensitivity sucrose erbium-doped fiber ring laser sensor

NASA Astrophysics Data System (ADS)

Khaleel, Wurood Abdulkhaleq; Al-Janabi, Abdul Hadi M.

2017-02-01

We investigate a high-sensitivity sucrose sensor based on a standard erbium-doped fiber ring laser incorporating a coreless fiber (CF). A single-mode-coreless-single mode (SCS) structure with a very low insertion loss has been constructed. The SCS fiber structure performed dual function as an intracavity fiber filter and/or a sensing element. The gain medium (erbium-doped fiber) is pumped by a 975-nm wavelength fiber coupled diode laser. Laser emission around 1537 nm with -2 dBm peak output power is obtained when a CF in SCS structure has a diameter of 125 μm. The 3-dB line-width of the laser is <0.14 nm, which is beneficial to high precision sensing. The sucrose concentration varied from 0% to 60%, and the relationship between the lasing wavelength and the sucrose concentration exhibited linear behavior (R2=0.996), with sensitivity of 0.16 nm/% was obtained. To improve the measurement sensitivity, the CF is etched by hydrofluoric acid. The splice joint of etched CF with SMF is a taper, which improves its sensitivity to sucrose changes. An average sensitivity of 0.57 nm/% and a high signal-to-noise ratio of 50 dB make the proposed sensor suitable for potential applications.

Consumption of sucrose from infancy increases the visceral fat accumulation, concentration of triglycerides, insulin and leptin, and generates abnormalities in the adrenal gland.

PubMed

Díaz-Aguila, Yadira; Castelán, Francisco; Cuevas, Estela; Zambrano, Elena; Martínez-Gómez, Margarita; Muñoz, Alvaro; Rodríguez-Antolín, Jorge; Nicolás-Toledo, Leticia

2016-03-01

Consumption of sugar-sweetened beverages promotes the development of metabolic syndrome (MetS) and type 2 diabetes mellitus in humans. One factor related to the appearance of MetS components is the dysfunction of the adrenal gland. In fact, the experimental generation of hyperglycemia has been associated with morphological and microvascular changes in the adrenal glands of rats. We hypothesized that high sucrose consumption from infancy promotes histological disruption of the adrenal glands associated with the appearance of metabolic syndrome indicators. Male Wistar rats were separated at weaning (21 days old) into two groups: free access to tap water (control group, C) or 30 % sucrose diluted in water (sugar-fed group). After 12 weeks, high sucrose consumption promoted an increase in visceral fat accumulation, adipose cell number, and insulin resistance. Also, a rise in the concentration of triglycerides, very low-density lipoprotein, insulin and leptin was observed. In control rats, a histomorphometric asymmetry between the right and left adrenal glands was found. In the sugar-fed group, sucrose consumption produced a major change in adrenal gland asymmetry. No changes in corticosterone serum level were observed in either group. Our results suggest that a high sucrose liquid-diet from early life alters the morphology of adrenocortical zones, leading to MetS indicators.

Counter effect of sucrose on ethanol-induced aggregation of protein.

PubMed

Yadav, Jay Kant; Chandani, N; Pande Prajakt, P R; Chauhan, Jyoti Bala

2010-12-01

The present paper is an attempt to study the mechanism of ethanol induced aggregation of chicken egg albumin and to stabilize the protein against ethanol induced aggregation. The protein aggregation was determined by monitoring the light scattering of protein aggregates spectrophotometrically. The protein undergoes certain structural changes in water-ethanol solution and the degree of aggregation was found to be linearly depending upon the concentration of alcohol used. The intrinsic fluorescence study showed a large blue shift in the λ(max) (16 nm) in the presence of 50% ethanol. The ANS fluorescence intensity was found to be gradually increasing with increasing concentration of ethanol. This indicates an increase in the hydrophobic cluster on the protein surface and as a result the hydrophobic interaction is the major driving force for the aggregate formation. Addition of sucrose significantly reduced the ethanol-induced protein aggregation. In presence of 50% sucrose the ethanol the aggregation was reduced to 5%. The study reveals that addition of sucrose brings out changes in the solvent distribution and prevents the structural changes in protein which lead the aggregation.

Effects of Fatty Acid Addition to Oil-in-water Emulsions Stabilized with Sucrose Fatty Acid Ester.

PubMed

Watanabe, Takamasa; Kawai, Takahiro; Nonomura, Yoshimune

2018-03-01

Adding fatty acids to an oil-in-water (O/W) emulsion changes the stability of the emulsion. In this study, we prepared a series of O/W emulsions consisting of oil (triolein/fatty acid mixture), water and a range of surfactants (sucrose fatty acid esters) with varying hydrophilic-lipophilic balance (HLB) in order to determine the effects of alkyl chain length and the degree of unsaturation of the fatty acid molecules on the stability of the emulsions. As a result, sucrose fatty acid esters with HLB = 5-7 were suitable for obtaining O/W emulsions. In addition, the creaming phenomenon was inhibited for 30 days or more when fatty acids having a linear saturated alkyl chain with 14 or more carbon atoms were added. These findings are useful for designing stable O/W emulsions for food and cosmetic products.

Rapid sucrose monitoring in green coffee samples using multienzymatic biosensor.

PubMed

Stredansky, Miroslav; Redivo, Luca; Magdolen, Peter; Stredansky, Adam; Navarini, Luciano

2018-07-15

Amperometric biosensor utilizing FAD-dependent glucose dehydrogenase (FAD-GDH) for a specific sucrose monitoring in green coffee is described. FAD-GDH was co-immobilized with invertase and mutarotase on a thin-layer gold planar electrode using chitosan. The biosensor showed a wide linearity (from 10 to 1200 μM), low detection limit (8.4 μM), fast response time (50 s), and appeared to be O2 independent. In addition the biosensors exhibited a good operational (3 days) and storage (1 year) stability. Finally, the results achieved from the biosensor measurements of sucrose in 17 samples of green coffee (Coffea arabica, C. canephora and C. liberica) were compared with those obtained by the standard HPLC method. The good correlation among results of real samples, satisfactory analytical performance and simple use of the presented biosensor make it suitable for application in coffee industry. Copyright © 2018 Elsevier Ltd. All rights reserved.

Ion-exchange chromatography purification of extracellular vesicles.

PubMed

Kosanović, Maja; Milutinović, Bojana; Goč, Sanja; Mitić, Ninoslav; Janković, Miroslava

2017-08-01

Despite numerous studies, isolating pure preparations of extracellular vesicles (EVs) has proven challenging. Here, we compared ion-exchange chromatography (IEC) to the widely used sucrose density gradient (SDG) centrifugation method for the purification of EVs. EVs in bulk were isolated from pooled normal human amniotic fluid (AF) by differential centrifugation followed by IEC or sucrose density gradient separation. The purity of the isolated EVs was evaluated by electrophoresis and lectin blotting/immuno blotting to monitor the distribution of total proteins, different EVs markers, and selected N-glycans. Our data showed efficient separation of negatively charged EVs from other differently charged molecules, while comparative profiling of EVs using SDG centrifugation confirmed anion-exchange chromatography is advantageous for EV purification. Finally, although this IEC-based method was validated using AF, the approach should be readily applicable to isolation of EVs from other sources as well.

Practical utilization of spICP-MS to study sucrose density gradient centrifugation for the separation of nanoparticles.

PubMed

Johnson, Monique E; Montoro Bustos, Antonio R; Winchester, Michael R

2016-11-01

Single particle inductively coupled plasma mass spectrometry (spICP-MS) is shown to be a practical technique to study the efficacy of rate-zonal sucrose density gradient centrifugation (SDGC) separations of mixtures of gold nanoparticles (AuNPs) in liquid suspension. spICP-MS enabled measurements of AuNP size distributions and particle number concentrations along the gradient, allowing unambiguous evaluations of the effectiveness of the separation. Importantly, these studies were conducted using AuNP concentrations that are directly relevant to environmental studies (sub ng mL -1 ). At such low concentrations, other techniques [e.g., dynamic light scattering (DLS), transmission and scanning electron microscopies (TEM and SEM), UV-vis spectroscopy, atomic force microscopy (AFM)] do not have adequate sensitivity, highlighting the inherent value of spICP-MS for this and similar applications. In terms of the SDGC separations, a mixture containing three populations of AuNPs, having mean diameters of 30, 80, and 150 nm, was fully separated, while separations of two other mixtures (30, 60, 100 nm; and 20, 50, 100 nm) were less successful. Finally, it is shown that the separation capacity of SDGC can be overwhelmed when particle number concentrations are excessive, an especially relevant finding in view of common methodologies taken in nanotechnology research. Graphical Abstract Characterization of the separation of a gold nanoparticle mixture by sucrose density gradient centrifugation by conventional and single particle ICP-MS analysis.

Differential compartmentation of sucrose and gentianose in the cytosol and vacuoles of storage root protoplasts from Gentiana Lutea L.

PubMed

Keller, F; Wiemken, A

1982-12-01

The storage roots of perennial Gentiana lutea L.plants contain several sugars. The predominant carbohydrate reserve is gentianose (β-D-glucopyranosyl-(1 → 6)-α-D-glucopyranosyl-(1 ↔ 2)-β-D-fructofuranoside). Vacuoles were isolated from root protoplasts and purified through a betaine density gradient. The yield was about 75%. Gentianose and gentiobiose were localized to 100% in the vacuoles, fructose and glucose to about 80%, and sucrose to only about 50%. Taking the volumes of the vacuolar and extravacuolar (cytosolic) compartments into account it is inferred that gentianose is located exclusively in the vacuoles, whilst sucrose is much more concentrated in the cytosol where it may play a role as a cryoprotectant. The concentration of fructose and glucose appeared to be similar on both sides of the tonoplast.

Heterotrophic cultivation of Chlorella pyrenoidosa using sucrose as the sole carbon source by co-culture with Rhodotorula glutinis.

PubMed

Wang, Shikai; Wu, Yong; Wang, Xu

2016-11-01

Heterotrophic cultivation of microalgae is a feasible alternative strategy to avoid the light limitation of photoautotrophic culture, but the heterotrophic utilization of disaccharides is difficult for microalgae. Aimed at this problem, a co-culture system was developed by mix culture of C. pyrenoidosa and R. glutinis using sucrose as the sole carbon source. In this system, C. pyrenoidosa could utilize glucose and fructose which were hydrolyzed from sucrose by R. glutinis. The highest specific growth rate and final cell number proportion of algae was 1.02day(-1) and 45%, respectively, when cultured at the initial algal cell number proportion of 95.24% and the final algal cell density was 111.48×10(6)cells/mL. In addition, the lipid content was also promoted due to the synergistic effects in mix culture. This study provides a novel approach using sucrose-riched wastes for the heterotrophic culture of microalgae and may effectively decrease the cost of carbon source. Copyright © 2016 Elsevier Ltd. All rights reserved.

Isolation and characterization of a mucosal triacylglycerol pool undergoing hydrolysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tipton AD IV; Frase, S.; Mansbach, C.M. II

1989-12-01

Absorbed and processed mucosal neutral lipid has been shown to be composed of at least two pools of triacylglycerol. One is likely to subserve chylomicron formation, and the other appears to be transported from the intestine via a nonlymphatic route. In the present study, 50 +/- 5% of the mucosal lipid pellets was centrifuged at 75,000 g.min (low-speed pellet (LSP)). Discontinuous sucrose density gradient centrifugation of LSP showed that 61 +/- 7% of the lipid banded at the 0.25-0.86 M sucrose interface. Neutral lipid analysis showed that this subfraction was only 58% triacylglycerol, suggesting it was undergoing hydrolysis. Active lipolyticmore » activity in vitro was found on incubation. The lipase had an alkaline pH optimum (pH 8.5) and persisted despite pancreatic ductular diversion. Lipolysis in vivo in a LSP fraction was shown by infusing (14C)glyceryltrioleate for 3.5 h followed by (3H)glyceryltrioleate for 30 min. Discontinuous sucrose density centrifugation of the LSP followed by an analysis of the lipids at the 0.25-0.86 M sucrose interface showed that 14C-neutral lipids were only 70 +/- 6% triacylglycerol, whereas 3H-neutral lipids were 88 +/- 2% triacylglycerol. 3H entered LSP slowly compared with the floating lipid in the same centrifuge tube. These studies suggest both in vivo and in vitro mucosal lipolysis by a specific, alkaline-active lipase. The turnover rate of LSP is likely to be slow by comparison with neutral lipid floating to the top of the centrifuge tube.« less

A High-Saturated-Fat, High-Sucrose Diet Aggravates Bone Loss in Ovariectomized Female Rats.

PubMed

Dong, Xiao-Li; Li, Chun-Mei; Cao, Si-Si; Zhou, Li-Ping; Wong, Man-Sau

2016-06-01

Estrogen deficiency in women and high-saturated fat, high-sucrose (HFS) diets have both been recognized as risk factors for metabolic syndrome. Studies on the combined actions of these 2 detrimental factors on the bone in females are limited. We sought to determine the interactive actions of estrogen deficiency and an HFS diet on bone properties and to investigate the underlying mechanisms. Six-month-old Sprague Dawley sham or ovariectomized (OVX) rats were pair fed the same amount of either a low-saturated-fat, low-sucrose (LFS) diet (13% fat calories; 15% sucrose calories) or an HFS diet (42% fat calories; 30% sucrose calories) for 12 wk. Blood, liver, and bone were collected for correspondent parameters measurement. Ovariectomy decreased bone mineral density in the tibia head (TH) by 62% and the femoral end (FE) by 49% (P < 0.0001). The HFS diet aggravated bone loss in OVX rats by an additional 41% in the TH and 37% in the FE (P < 0.05). Bone loss in the HFS-OVX rats was accompanied by increased urinary deoxypyridinoline concentrations by 28% (P < 0.05). The HFS diet induced cathepsin K by 145% but reduced osteoprotegerin mRNA expression at the FE of the HFS-sham rats by 71% (P < 0.05). Ovariectomy significantly increased peroxisome proliferator-activated receptor γ mRNA expression by 136% and 170% at the FE of the LFS- and HFS-OVX rats, respectively (P < 0.05). The HFS diet aggravated ovariectomy-induced lipid deposition and oxidative stress (OS) in rat livers (P < 0.05). Trabecular bone mineral density at the FE was negatively correlated with rat liver malondialdehyde concentrations (R(2) = 0.39; P < 0.01). The detrimental actions of the HFS diet and ovariectomy on bone properties in rats occurred mainly in cancellous bones and were characterized by a high degree of bone resorption and alterations in OS. © 2016 American Society for Nutrition.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hanft, J.M.; Jones, R.J.

This study was designed to compare the uptake and distribution of /sup 14/C among fructose, glucose, sucrose, and starch in the cob, pedicel, and endosperm tissues of maize (Zea mays L.) kernels induced to abort by high temperature with those that develop normally. Kernels cultured in vitro at 309 and 35/sup 0/C were transferred to (/sup 14/C)sucrose media 10 days after pollination. Kernels cultured at 35/sup 0/C aborted prior to the onset of linear dry matter accumulation. Significant uptake into the cob, pedicel, and endosperm of radioactivity associated with the soluble and starch fractions of the tissues was detected aftermore » 24 hours in culture on atlageled media. After 8 days in culture on (/sup 14/C)sucrose media, 48 and 40% of the radioactivity associated with the cob carbohydrates was found in the reducing sugars at 30 and 35/sup 0/C, respectively. Of the total carbohydrates, a higher percentage of label was associated with sucrose and lower percentage with fructose and glucose in pedicel tissue of kernels cultured at 35/sup 0/C compared to kernels cultured at 30/sup 0/C. These results indicate that sucrose was not cleaved to fructose and glucose as rapidly during the unloading process in the pedicel of kernels induced to abort by high temperature. Kernels cultured at 35/sup 0/C had a much lower proportion of label associated with endosperm starch (29%) than did kernels cultured at 30/sup 0/C (89%). Kernels cultured at 35/sup 0/C had a correspondingly higher proportion of /sup 14/C in endosperm fructose, glucose, and sucrose.« less

Different subcellular localization of neurotensin-receptor and neurotensin-acceptor sites in the rat brain dopaminergic system.

PubMed

Schotte, A; Rostène, W; Laduron, P M

1988-04-01

The subcellular localization of neurotensin-receptor sites (NT2 sites) and neurotensin-acceptor sites (NT1 sites) was studied in rat caudate-putamen by isopycnic centrifugation in sucrose density gradients. [3H]Neurotensin binding to NT2 sites occurred as a major peak at higher sucrose densities, colocalized with [3H]dopamine uptake, and as a small peak at a lower density; whereas binding to NT1 sites occurred as a single large peak at an intermediate density. 6-Hydroxydopamine lesions of the median forebrain bundle resulted in a total loss of NT2 sites in the caudate-putamen but did not affect NT2 sites in the nucleus accumbens and the olfactory tubercle. NT1 sites were not affected. Kainic acid injections into the rat caudate-putamen led to a partial decrease of NT1 sites in this region 5 days later. After a few weeks they returned to normal. Therefore NT2 sites are probably associated with presynaptic nigrostriatal dopaminergic terminals in the caudate-putamen but not in the nucleus accumbens and the olfactory tubercle. A possible association of NT1 sites with glial cells is suggested.

In depth study of acrylamide formation in coffee during roasting: role of sucrose decomposition and lipid oxidation.

PubMed

Kocadağlı, Tolgahan; Göncüoğlu, Neslihan; Hamzalıoğlu, Aytül; Gökmen, Vural

2012-09-01

Coffee, as a source of acrylamide, needs to be investigated in depth to understand the contribution of different precursors. This study aimed to investigate the contributions of sucrose decomposition and lipid oxidation on acrylamide formation in coffee during roasting. Coffee beans and model systems were used to monitor the accumulation of neo-formed carbonyls during heating through sucrose decomposition and lipid oxidation. High resolution mass spectrometry analyses confirmed the formation of 5-hydroxymethylfurfural (HMF) and 3,4-dideoxyosone, which were identified as the major sugar decomposition products in both roasted coffee and model systems. Among others, 2-octenal, 2,4-decadienal, 2,4-heptadienal, 4-hydroxynonenal, and 4,5-epoxy-2-decenal were identified in relatively high quantities in roasted coffee. Formation and elimination of HMF in coffee during roasting had a kinetic pattern similar to those of acrylamide. Its concentration rapidly increased within 10 min followed by an exponential decrease afterward. The amount of lipid oxidation products tended to increase linearly during roasting. It was concluded from the results that roasting formed a pool of neo-formed carbonyls from sucrose decomposition and lipid oxidation, and they play certain role on acrylamide formation in coffee.

The Isolation and Partial Characterization of a Membrane Fraction Containing Phytochrome 12

PubMed Central

Marmé, Dieter; Mackenzie, John M.; Boisard, Jean; Briggs, Winslow R.

1974-01-01

If 4-day-old dark-grown zucchini squash seedlings (Cucurbita pepo L. cv. Black Beauty) are exposed briefly to red light, subsequent cell fractionation yields about 40% of the total extractable phytochrome in the far red-absorbing form bound to a particulate fraction. The amount of far red-absorbing phytochrome in the pellet is strongly dependent on the Mg concentration in the extraction medium. The apparent density of the Pfr-containing particles following sedimentation on sucrose gradients corresponds to 15% (w/w) sucrose with 0.1 mm Mg and 40% sucrose with 10 mm Mg. This particulate fraction could be readily separated from mitochondria and other particulate material by taking advantage of these apparent density changes with changes in Mg concentration. Electron microscopy of negatively stained preparations shows that with 1 mm Mg only minute particles are present. These were too small to reveal structural detail with this technique. With 3 mm Mg, separate membranous vesicles between 400 and 600 Ångstroms in diameter appear. At higher Mg concentrations, the vesicles aggregate, causing obvious turbity. The effect of Mg on vesicle formation and aggregation is completely reversible. Above 10 mm Mg, vesicle aggregation persists, but the percentage of bound Pfr decreases. Images PMID:16658871

Analysis of Chromatin Organisation

ERIC Educational Resources Information Center

Szeberenyi, Jozsef

2011-01-01

Terms to be familiar with before you start to solve the test: chromatin, nucleases, sucrose density gradient centrifugation, melting point, gel electrophoresis, ethidium bromide, autoradiography, Southern blotting, Northern blotting, Sanger sequencing, restriction endonucleases, exonucleases, linker DNA, chloroform extraction, nucleosomes,…

Biology Notes.

ERIC Educational Resources Information Center

School Science Review, 1980

1980-01-01

Outlines a variety of laboratory procedures, discussions, and demonstrations including in vitro contraction of muscle fibres and muscle proteins, sucrose density-gradient centrifugation, fern spore development, digestion of starch, construction of a small mammal trap, microscope selection, and occurrence and toxicity of mycotoxins. (GS)

Kinetically Determined Hygroscopicity and Efflorescence of Sucrose-Ammonium Sulfate Aerosol Droplets under Lower Relative Humidity.

PubMed

Wang, Lin-Na; Cai, Chen; Zhang, Yun-Hong

2017-09-14

Organic aerosols will likely form in semisolid, glassy, and high viscous state in the atmosphere, which show nonequilibrium kinetic characteristics at low relative humidity (RH) conditions. In this study, we applied optical tweezers to investigate the water transport in a sucrose/(NH 4 ) 2 SO 4 droplet with high organic to inorganic mole ratio (OIR). The characteristic time ratio between the droplet radius and the RH was used to describe the water mass transfer difference dependent on RH. For OIR greater than 1:1 in sucrose/(NH 4 ) 2 SO 4 droplets, the characteristic time ratio at low RH (<∼30% RH) was two orders magnitude greater than that at high RH (>∼60%). We also coupled vacuum FTIR spectrometer and a high-speed photography to study the efflorescence process in sucrose/(NH 4 ) 2 SO 4 droplets with low OIR. The crystalline fraction of (NH 4 ) 2 SO 4 was used to understand efflorescence behavior when the RH was linearly decreasing with a velocity of 1.2% RH min -1 . Because of suppression of (NH 4 ) 2 SO 4 nucleation by addition of sucrose, the efflorescence relative humidity (ERH) of (NH 4 ) 2 SO 4 decrease from the range of ∼48.2% to ∼36.1% for pure (NH 4 ) 2 SO 4 droplets to from ∼44.7% to ∼25.4%, from ∼43.2% to ∼21.2%, and from ∼41.7% to ∼21.1% for the mixed droplets with OIR of 1:4, 1:3, and 1:2, respectively. No crystallization was observed when the OIR is higher than 1:1. Suppression of (NH 4 ) 2 SO 4 crystal growth was also observed under high viscous sucrose/(NH 4 ) 2 SO 4 droplets at lower RH.

Kernel Abortion in Maize 1

PubMed Central

Hanft, Jonathan M.; Jones, Robert J.

1986-01-01

This study was designed to compare the uptake and distribution of 14C among fructose, glucose, sucrose, and starch in the cob, pedicel, and endosperm tissues of maize (Zea mays L.) kernels induced to abort by high temperature with those that develop normally. Kernels cultured in vitro at 30 and 35°C were transferred to [14C]sucrose media 10 days after pollination. Kernels cultured at 35°C aborted prior to the onset of linear dry matter accumulation. Significant uptake into the cob, pedicel, and endosperm of radioactivity associated with the soluble and starch fractions of the tissues was detected after 24 hours in culture on labeled media. After 8 days in culture on [14C]sucrose media, 48 and 40% of the radioactivity associated with the cob carbohydrates was found in the reducing sugars at 30 and 35°C, respectively. This indicates that some of the sucrose taken up by the cob tissue was cleaved to fructose and glucose in the cob. Of the total carbohydrates, a higher percentage of label was associated with sucrose and a lower percentage with fructose and glucose in pedicel tissue of kernels cultured at 35°C compared to kernels cultured at 30°C. These results indicate that sucrose was not cleaved to fructose and glucose as rapidly during the unloading process in the pedicel of kernels induced to abort by high temperature. Kernels cultured at 35°C had a much lower proportion of label associated with endosperm starch (29%) than did kernels cultured at 30°C (89%). Kernels cultured at 35°C had a correspondingly higher proportion of 14C in endosperm fructose, glucose, and sucrose. These results indicate that starch synthesis in the endosperm is strongly inhibited in kernels induced to abort by high temperature even though there is an adequate supply of sugar. PMID:16664847

Immunological Evidence for the Existence of a Carrier Protein for Sucrose Transport in Tonoplast Vesicles from Red Beet (Beta vulgaris L.) Root Storage Tissue.

PubMed Central

Getz, H. P.; Grosclaude, J.; Kurkdjian, A.; Lelievre, F.; Maretzki, A.; Guern, J.

1993-01-01

Monoclonal antibodies were raised in mice against a highly purified tonoplast fraction from isolated red beet (Beta vulgaris L. ssp. conditiva) root vacuoles. Positive hybridoma clones and sub-clones were identified by prescreening using an enzyme-linked immunosorbent assay (ELISA) and by postscreening using a functional assay. This functional assay consisted of testing the impact of hybridoma supernatants and antibody-containing ascites fluids on basal and ATP-stimulated sugar uptake in vacuoles, isolated from protoplasts, as well as in tonoplast vesicles, prepared from tissue homogenates of red beet roots. Antibodies from four clones were particularly positive in ELISAs and they inhibited sucrose uptake significantly. These antibodies were specific inhibitors of sucrose transport, but they exhibited relatively low membrane and species specificity since uptake into red beet root protoplasts and sugarcane tonoplast vesicles was inhibited as well. Fast protein liquid chromatography assisted size exclusion chromatography on Superose 6 columns yielded two major peaks in the 55 to 65-kD regions and in the 110- to 130-kD regions of solubilized proteins from red beet root tonoplasts, which reacted positively in immunoglobulin-M(IgM)-specific ELISAs with anti-sugarcane tonoplast monoclonal IgM antibodies. Only reconstituted proteoliposomes containing polypeptides from the 55- to 65-kD band took up [14C]-sucrose with linear rates for 2 min, suggesting that this fraction contains the tonoplast sucrose carrier. PMID:12231863

New developments on size-dependent growth applied to the crystallization of sucrose

NASA Astrophysics Data System (ADS)

Martins, P. M.; Rocha, F.

2007-12-01

The effect of crystal size on the growth rate of sucrose (C 12H 22O 11) at 40 °C is investigated from a theoretical and an experimental point of view. Based on new perspectives resulting from the recently introduced spiral nucleation model [P.M. Martins, F. Rocha, Surf. Sci. 601 (2007) 3400], crystal growth rates are expressed in terms of mass deposition per time and crystal volume units. This alternative definition is demonstrated to be size-independent over the considered supersaturation range. The conventional overall growth rate expressed per surface area units is found to be linearly dependent on crystal size. The advantages of the "volumetric" growth rate concept are discussed. Sucrose dissolution rates were measured under reciprocal conditions of the growth experiments in order to investigate the two-way effect of crystal size on mass transfer rates and on the integration kinetics. Both effects are adequately described by combining a well-established diffusion-integration model and the spiral nucleation mechanism.

Skin optical clearing potential of disaccharides

NASA Astrophysics Data System (ADS)

Feng, Wei; Shi, Rui; Ma, Ning; Tuchina, Daria K.; Tuchin, Valery V.; Zhu, Dan

2016-08-01

Skin optical clearing can significantly enhance the ability of biomedical optical imaging. Some alcohols and sugars have been selected to be optical clearing agents (OCAs). In this work, we paid attention to the optical clearing potential of disaccharides. Sucrose and maltose were chosen as typical disaccharides to compare with fructose, an excellent monosaccharide-OCA, by using molecular dynamics simulation and an ex vivo experiment. The experimental results indicated that the optical clearing efficacy of skin increases linearly with the concentration for each OCA. Both the theoretical predication and experimental results revealed that the two disaccharides exerted a better optical clearing potential than fructose at the same concentration, and sucrose is optimal. Since maltose has an extremely low saturation concentration, the other two OCAs with saturation concentrations were treated topically on rat skin in vivo, and optical coherence tomography imaging was applied to monitor the optical clearing process. The results demonstrated that sucrose could cause a more significant increase in imaging depth and signal intensity than fructose.

Renewable Hydrogen Carrier - Carbohydrate: Constructing the Carbon-Neutral Carbohydrate Economy

DTIC Science & Technology

2011-01-31

temperature. High fructose corn syrup , low-cost sucrose replacement, is made by stabilized glucose isomerase, which can work at ~60 °C for even about two...sustainable production, high -density storage, costly infrastructure, to eliminating safety concern. The use of renewable carbohydrate as a high -density...100% selectivity of enzymes, modest reaction conditions, and high -purity of generated hydrogen, carbohydrate is a promising hydrogen carrier for end

On the identity of the last known stable radical in X-irradiated sucrose

NASA Astrophysics Data System (ADS)

Kusakovskij, Jevgenij; De Cooman, Hendrik; Sagstuen, Einar; Callens, Freddy; Vrielinck, Henk

2017-04-01

Identification of radiation-induced radicals in relatively simple molecules is a prerequisite for the understanding of reaction pathways of the radiation chemistry of complex systems. Sucrose presents an additional practical interest as a versatile radiation dosimetric system. In this work, we present a periodic density functional theory study aimed to identify the fourth stable radical species in this carbohydrate. The proposed model is a fragment suspended in the lattice by hydrogen bonds with an unpaired electron at the original C5' carbon of the fructose unit. It requires a double scission of the ring accompanied by substantial chemical and geometric reorganization.

Production of gymnemic acid depends on medium, explants, PGRs, color lights, temperature, photoperiod, and sucrose sources in batch culture of Gymnema sylvestre.

PubMed

Ahmed, A Bakrudeen Ali; Rao, A S; Rao, M V; Taha, Rosna Mat

2012-01-01

Gymnema sylvestre (R.Br.) is an important diabetic medicinal plant which yields pharmaceutically active compounds called gymnemic acid (GA). The present study describes callus induction and the subsequent batch culture optimization and GA quantification determined by linearity, precision, accuracy, and recovery. Best callus induction of GA was noticed in MS medium combined with 2,4-D (1.5 mg/L) and KN (0.5 mg/L). Evaluation and isolation of GA from the calluses derived from different plant parts, namely, leaf, stem and petioles have been done in the present case for the first time. Factors such as light, temperature, sucrose, and photoperiod were studied to observe their effect on GA production. Temperature conditions completely inhibited GA production. Out of the different sucrose concentrations tested, the highest yield (35.4 mg/g d.w) was found at 5% sucrose followed by 12 h photoperiod (26.86 mg/g d.w). Maximum GA production (58.28 mg/g d.w) was observed in blue light. The results showed that physical and chemical factors greatly influence the production of GA in callus cultures of G. sylvestre. The factors optimized for in vitro production of GA during the present study can successfully be employed for their large-scale production in bioreactors.

Growth Kinetics, Carbohydrate, and Leaf Phosphate Content of Clover (Trifolium subterraneum L.) after Transfer to a High CO2 Atmosphere or to High Light and Ambient Air 1

PubMed Central

Morin, Francoise; André, Marcel; Betsche, Thomas

1992-01-01

Intact air-grown (photosynthetic photon flux density, 400 microeinsteins per square meter per second) clover plants (Trifolium subterraneum L.) were transfered to high CO2 (4000 microliters CO2 per liter; photosynthetic photon flux density, 400 microeinsteins per square meter per second) or to high light (340 microliters CO2 per liter; photosynthetic photon flux density, 800 microeinsteins per square meter per second) to similarly stimulate photosynthetic net CO2 uptake. The daily increment of net CO2 uptake declined transiently in high CO2, but not in high light, below the values in air/standard light. After about 3 days in high CO2, the daily increment of net CO2 uptake increased but did not reach the high light values. Nightly CO2 release increased immediately in high light, whereas there was a 3-day lag phase in high CO2. During this time, starch accumulated to a high level, and leaf deterioration was observed only in high CO2. After 12 days, starch was two- to threefold higher in high CO2 than in high light, whereas sucrose was similar. Leaf carbohydrates were determined during the first and fourth day in high CO2. Starch increased rapidly throughout the day. Early in the day, sucrose was low and similar in high CO2 and ambient air (same light). Later, sucrose increased considerably in high CO2. The findings that (a) much more photosynthetic carbon was partitioned into the leaf starch pool in high CO2 than in high light, although net CO2 uptake was similar, and that (b) rapid starch formation occurred in high CO2 even when leaf sucrose was only slightly elevated suggest that low sink capacity was not the main constraint in high CO2. It is proposed that carbon partitioning between starch (chloroplast) and sucrose (cytosol) was perturbed by high CO2 because of the lack of photorespiration. Total phosphate pools were determined in leaves. Concentrations based on fresh weight of orthophosphate, soluble esterified phosphate, and total phosphate markedly declined during 13 days of exposure of the plants to high CO2 but changed little in high light/ambient air. During this time, the ratio of orthophosphate to soluble esterified phosphate decreased considerably in high CO2 and increased slightly in high light/ambient air. It appears that phosphate uptake and growth were similarly stimulated by high light, whereas the coordination was weak in high CO2. PMID:16668889

An Experiment Using Sucrose Density Gradients in the Undergraduate Biochemistry Laboratory.

ERIC Educational Resources Information Center

Turchi, Sandra L.; Weiss, Monica

1988-01-01

Describes an experiment to be performed in an undergraduate biochemistry laboratory that is based on a gradient centrifugation system employing a simple bench top centrifuge, a freezer, and frozen surcose gradient solution to separate macromolecules and subcellular components. (CW)

Environmentally Benign Battlefield Effects Black Smoke Simulator

DTIC Science & Technology

2006-11-01

tested and results Fuel Oxidizer Color of Smoke Density of Smoke Sugar (Sucrose) KNO3 Grey Medium Dextrin KNO3 Grey Thin Microcrystalline...design. 3.5 Initial Prototype Scale Fiberboard Testing Several quality black smoke formulations were identified in the small pellet testing to

Effects of agave nectar versus sucrose on weight gain, adiposity, blood glucose, insulin, and lipid responses in mice.

PubMed

Hooshmand, Shirin; Holloway, Brittany; Nemoseck, Tricia; Cole, Sarah; Petrisko, Yumi; Hong, Mee Young; Kern, Mark

2014-09-01

Agave nectar is a fructose-rich liquid sweetener derived from a plant, and is often promoted as a low glycemic alternative to refined sugar. However, little scientific research has been conducted in animals or humans to determine its metabolic and/or health effects. The aim of this study was to explore the influence of agave nectar versus sucrose on weight gain, adiposity, fasting plasma blood glucose, insulin, and lipid levels. Eighteen (n=18) male ICR mice (33.8±1.6 g) were divided into two groups (n=6 for agave nectar and n=12 for sucrose) and provided free access to one of two diets of equal energy densities differing only in a portion of the carbohydrate provided. Diets contained 20% carbohydrate (by weight of total diet) from either raw agave nectar or sucrose. Epididymal fat pads were excised, and blood was collected after 34 days. Weight gain (4.3±2.2 vs. 8.4±3.4 g), fat pad weights (0.95±0.54 vs. 1.75±0.66 g), plasma glucose (77.8±12.2 vs. 111.0±27.9 mg/dL), and insulin (0.61±0.29 vs. 1.46±0.81 ng/mL) were significantly lower (P≤.05) for agave nectar-fed mice compared to sucrose-fed mice respectively. No statistically significant differences in total cholesterol or triglycerides were detected. These results suggest that in comparison to sucrose, agave nectar may have a positive influence on weight gain and glucose control. However, more research with a larger sample of animals and/or with human subjects is warranted.

Overnutrition in spiny mice (Acomys cahirinus): beta-cell expansion leading to rupture and overt diabetes on fat-rich diet and protective energy-wasting elevation in thyroid hormone on sucrose-rich diet.

PubMed

Shafrir, E

2000-01-01

The investigation of diabetes propensity in spiny mice, performed in Geneva and Jerusalem colonies, is reviewed. Spiny mice live in semi-desert regions of the eastern Mediterranean countries. Those transferred to Geneva in the 1950s were maintained on a rodent diet supplemented by fat-rich seeds. They became obese, exhibited pancreatic islet hyperplasia and hypertrophy. Low insulin secretion response was characteristic of this species, despite ample pancreatic content of insulin. After a few months, diabetes with ketosis occurred, often suddenly, in association with islet cell disintegration. In Jerusalem the spiny mice were collected from their native habitat and placed on diets containing 50% sucrose or fat-rich seed diets. On a sucrose-rich diet, spiny mice developed hepatomegaly, lipogenic enzyme hyperactivity, and elevation in very low density lipoproteins as a result of metabolism of the fructose component mainly in the liver. No overt diabetes or pancreatic islet disintegration were observed, although insulin content and beta-cell hypertrophy and hyperplasia were apparent. On a fat-rich diet, spiny mice exhibited marked weight gain, adipose tissue growth and low hepatic lipogenesis. The obesity was accompanied by mild hyperglycemia and hyperinsulinemia with glucose intolerance leading to an occasional glucosuria after several months on the diet. The sucrose diet induced an extrathyroidal elevation of triiodothyronine (T(3)). Serum T(3) level and hepatic T(4)-T(3) conversion were increased, while serum T(4) levels tended to decrease. The activity of the T(3)-inducible hepatic mitochondrial FAD-glycerophosphate oxidase and K(+)/Na(+)-ATPase, as well as body temperature were increased, indicating that the sucrose diet was associated with enhanced thermogenesis and energy-wasting metabolic cycling. The sucrose-rich diet might exert an adaptive thermogenesis-mediated defense mechanism, protecting against excessive weight gain and disruptive pancreatic islet lesion. After 18 months maintenance on sucrose-rich versus fat-rich diets the number of animals surviving was significantly higher on the sucrose diet whereas on the fat diet a significant number of animals succumbed to expansive islet cell disruption and diabetes.

Molecular Interactions in the Replication of Mouse Hepatitis Virus

DTIC Science & Technology

1987-05-08

viruses of vertebrate species which cause a variety of acute 1 2 Figure 1. Mouse hepatitis virus , strain A59. (a) Negative stain of a virion...coronaviruses and the human corona - virus 229E (Weiss and Leibowitz, 1981). Antigenic relationships. Coronaviruses fall into two main groups...rate zonal and isopycnic centrifugation on density gradients. The density of corona - viruses in sucrose is 1.16 to 1.18 g/ml. Virions contain RNA

Purification of Torpedo californica post-synaptic membranes and fractionation of their constituent proteins.

PubMed Central

Elliott, J; Blanchard, S G; Wu, W; Miller, J; Strader, C D; Hartig, P; Moore, H P; Racs, J; Raftery, M A

1980-01-01

A rapid methof for preparation of membrane fractions highly enriched in nicotinic acetylcholine receptor from Torpedo californica electroplax is described. The major step in this purification involves sucrose-density-gradient centrifugation in a reorienting rotor. Further purification of these membranes can be achieved by selective extraction of proteins by use of alkaline pH or by treatment with solutions of lithium di-idosalicylate. The alkali-treated membranes retain functional characteristics of the untreated membranes and in addition contain essentially only the four polypeptides (mol.wts. 40000, 50000, 60000 and 65000) characteristic of the receptor purified by affinity chromatography. Dissolution of the purified membranes or of the alkali-treated purified membranes in sodium cholate solution followed by sucrose-density-gradient centrifugation in the same detergent solution yields solubilized receptor preparations comparable with the most highly purified protein obtained by affinity-chromatographic procedures. Images Fig. 1. Fig. 2. Fig. 3. Fig. 5. Fig. 7. PLATE 1 PMID:7387629

The Influence of Assay Design, Blinding, and Gymnema sylvestre on Sucrose Detection by Humans.

PubMed

Aleman, Max G; Marconi, Lauren J; Nguyen, Nam H; Park, Jae M; Patino, Maria M; Wang, Yuchi; Watkins, Celeste S; Shelley, Chris

2016-01-01

The detection and grading of tastes corresponding to different taste modalities can be tested in engaging laboratory sessions using students themselves as test subjects. This article describes a series of experiments in which data pertaining to the detection of salty and sweet tastes are obtained, and the ability of the herb Gymnema sylvestre to disrupt the detection of sucrose is quantified. The effects of blinding and different assay designs on EC50 estimation are also investigated. The data obtained allow for substantial data analysis, including non-linear regression using fixed and free parameters to quantify dose-response relationships, and the use of often under-utilized permutation tests to determine significant differences when the underlying data display heteroscedasticity.

The Influence of Assay Design, Blinding, and Gymnema sylvestre on Sucrose Detection by Humans

PubMed Central

Aleman, Max G.; Marconi, Lauren J.; Nguyen, Nam H.; Park, Jae M.; Patino, Maria M.; Wang, Yuchi; Watkins, Celeste S.; Shelley, Chris

2016-01-01

The detection and grading of tastes corresponding to different taste modalities can be tested in engaging laboratory sessions using students themselves as test subjects. This article describes a series of experiments in which data pertaining to the detection of salty and sweet tastes are obtained, and the ability of the herb Gymnema sylvestre to disrupt the detection of sucrose is quantified. The effects of blinding and different assay designs on EC50 estimation are also investigated. The data obtained allow for substantial data analysis, including non-linear regression using fixed and free parameters to quantify dose-response relationships, and the use of often under-utilized permutation tests to determine significant differences when the underlying data display heteroscedasticity. PMID:27980466

Insecticidal and repellent activities of insecticide-sucrose solutions to Culex pipiens molestus (Diptera: Culicidae) under laboratory and field conditions.

PubMed

Shin, Ehyun; Park, Chan; Ahn, Young-Joon; Lee, Dong-Kyu; Chang, Kyu-Sik

2011-06-01

Culex pipiens molestus Forskal has been reported as a dominant species in underground structures of urban areas in the Republic of Korea (ROK) during all seasons and becomes bothersome to humans in late autumn and winter. Most Cx. pipiens molestus in septic tanks are controlled in the ROK using larvicides such as Bt and IGR. However, there are a number of problems associated with larvicides, such as high cost and requirement for frequent use. In the present work, a new control method for Cx. pipiens molestus in septic tanks by using mixtures of sucrose solution with insecticides was investigated. The insecticidal and repellent activities of ten insecticides were evaluated for best control of Cx. pipiens molestus in septic tanks. Firstly, differences in susceptibilities to insecticides were evaluated in topical assays by forced direct contact bioassay and in a screened wire cage by free direct contact bioassay. The difference in insecticide susceptibility in the mosquitoes was the result of repellency by the insecticides. In three septic tanks, the density of Culex mosquitoes was sharply reduced by a deltamethrin-sucrose solution kit. The results demonstrated the potential for mosquito control by deltamethrin-sucrose solution, and the study offers basic information related to mosquito control in septic tanks. Copyright © 2011 Society of Chemical Industry.

[In vitro utilization of fructooligosaccharide by streptococci mutans].

PubMed

Linardi, M M; Rosa, O P; Buzalaf, M A; Torres, S A

2001-01-01

Neosugar is the trade name of a fructooligosaccharide (FOS) whose utilization by oral bacteria is not well known yet. The aim of the present study was to evaluate in vitro the effect of this product on the growth, fermentation and production of plaque by mutans streptococci: S. mutans, serotypes c, e and f, S. sobrinus, serotype d, S. downei, serotype h, S. cricetus, serotype a and S. rattus, serotype b. The evaluation of growth was carried out in Brain Heart Infusion (BHI) broths containing or not sucrose and FOS and in buffered broths having glucose or FOS as carbon sources, through optical density reading in spectrophotometer after 24 hours of incubation at 37 degrees C. Thereafter the reading of pH was made in the same media. The plaque produced on glass sticks in BHI broths containing 5% sucrose or FOS was weighed and carbohydrates and proteins were assayed. The possible cariogenicity of Neosugar was confirmed, since it sustained the same growth and intensity of fermentation of sucrose in BHI broth for all streptococci and permitted in vitro production of plaque by some of them. The amount of plaque as well as its content of proteins and carbohydrates were smaller than those produced with sucrose, although the difference was statistically significant only for carbohydrates.

New biobased high functionality polyols and their use in polyurethane coatings.

PubMed

Pan, Xiao; Webster, Dean C

2012-02-13

High-functionality polyols for application in polyurethanes (PUs) were prepared by epoxide ring-opening reactions from epoxidized sucrose esters of soybean oil-epoxidized sucrose soyates-in which secondary hydroxyl groups were generated from epoxides on fatty acid chains. Ester polyols were prepared by using a base-catalyzed acid-epoxy reaction with carboxylic acids (e.g., acetic acid); ether polyols were prepared by using an acid-catalyzed alcohol-epoxy reaction with monoalcohols (e.g., methanol). The polyols were characterized by using gel permeation chromatography, FTIR spectroscopy, (1)H NMR spectroscopy, differential scanning calorimetry (DSC), and viscosity measurements. PU thermosets were prepared by using aliphatic polyisocyanates based on isophorone diisocyanate and hexamethylene diisocyanate. The properties of the PUs were studied by performing tensile testing, dynamic mechanical analysis, DSC, and thermogravimetric analysis. The properties of PU coatings on steel substrates were evaluated by using ASTM methods to determine coating hardness, adhesion, solvent resistance, and ductility. Compared to a soy triglyceride polyol, sucrose soyate polyols provide greater hardness and range of cross-link density to PU thermosets because of the unique structure of these macromolecules: well-defined compact structures with a rigid sucrose core coupled with high hydroxyl group functionality. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Protein-based microhydraulic transport for controllable actuation

NASA Astrophysics Data System (ADS)

Sundaresan, Vishnu Baba; Leo, Donald J.

2006-03-01

Plants have the ability to develop large mechanical force from chemical energy available with bio-fuels. The energy released by the cleavage of a terminal phosphate ion during the hydrolysis of a bio- fuel assists the transport of ions and fluids in cellular homeostasis. Materials that develop pressure and hence strain similar to the response of plants to an external stimuli are classified as nastic materials. Calculations for controlled actuation of an active material inspired by biological transport mechanism demonstrated the feasibility of developing such a material with actuation energy densities on the order of 100 kJ/m 3. The mathematical model for a simplified proof of concept actuator referred to as micro hydraulic actuator uses ion transporters extracted from plants reconstituted on a synthetic bilayer lipid membrane (BLM). Thermodynamic model of the concept actuator predicted the ability to develop 5 percent normalized deformation in thickness of the micro- hydraulic actuator. Controlled fluid transport through AtSUT4 (Proton-sucrose co-transporter from Arabidopsis thaliana) reconstituted on a 1-Palmitoyl-2-Oleoyl-sn-Glycero-3-[Phospho-L- Serine] (Sodium Salt) (POPS), 1-Palmitoyl-2-Oleoyl-sn-Glycero-3- Phosphoethanolamine (POPE) BLM on a porous lead silicate glass plate (50μm with 61μm pitch) was driven by proton gradient. Bulk fluid flux of 1.2 μl/min was observed for each microliter of AtSUT4 transporter suspension (16.6 mg/ml in pH7.0 medium) reconstituted on the BLM. The flux rate is observed to be dependent on the concentration of sucrose present in pH4 buffer. Flux rate of 10 μl/min is observed for 5 mM sucrose in the first 10 minutes. The observed flux scales linearly with BLM area and the amount of proteins reconstituted on the lipid membrane. This article details the next step in the development of the micro hydraulic actuator - fluid transport driven by exergonic Adenosine triphosphate (ATP) hydrolysis reaction in the presence of ATP-phosphohydrolase (red beet ATP-ase) enzyme in the reconstituted bilayer.

Real-time monitoring of sucrose, sorbitol, d-glucose and d-fructose concentration by electromagnetic sensing.

PubMed

Harnsoongnoen, Supakorn; Wanthong, Anuwat

2017-10-01

Magnetic sensing at microwave frequencies for real-time monitoring of sucrose, sorbitol, d-glucose and d-fructose concentrations is reported. The sensing element was designed based on a coplanar waveguide (CPW) loaded with a split ring resonator (SRR), which was fabricated on a DiClad 880 substrate with a thickness of 1.6mm and relative permittivity (ε r ) of 2.2. The magnetic sensor was connected to a Vector Network Analyzer (VNA) and the electromagnetic interaction between the samples and sensor was analyzed. The magnitude of the transmission coefficient (S 21 ) was used as an indicator to detect the solution sample concentrations ranging from 0.04 to 0.20g/ml. The experimental results confirmed that the developed system using microwaves for the real-time monitoring of sucrose, sorbitol, d-glucose and d-fructose concentrations gave unique results for each solution type and concentration. Moreover, the proposed sensor has a wide dynamic range, high linearity, fast operation and low-cost. Copyright © 2017 Elsevier Ltd. All rights reserved.

Non-nutritive sweeteners are not super-normal stimuli

PubMed Central

Antenucci, Rachel G.; Hayes, John E.

2014-01-01

Background It is often claimed that non-nutritive sweeteners (NNS) are ‘sweeter than sugar’, with the implicit implication high potency sweeteners are super-normal stimuli that encourage exaggerated responses. This study aimed to investigate the perceived sweetness intensity of a variety of nutritive (Sucrose, Maple Syrup, and Agave Nectar) and NNS (Acesulfame-K (AceK), Rebaudioside A (RebA), Aspartame, and Sucralose) in a large cohort of untrained participants using contemporary psychophysical methods. Methods Participants (n=401 total) rated the intensity of sweet, bitter, and metallic sensations for nutritive and NNS in water using the general labeled magnitude scale (gLMS). Results Sigmoidal Dose-Response functions were observed for all stimuli except AceK. That is, sucrose follows a sigmoidal function if the data are not artifactually linearized via prior training. More critically, there is no evidence that NNS have a maximal sweetness (intensity) greater than sucrose; indeed, the maximal sweetness for AceK, RebA and Sucralose were significantly lower than for concentrated sucrose. For these sweeteners, mixture suppression due to endogenous dose-dependent bitter or metallic sensations appears to limit maximal perceived sweetness. Conclusions In terms of perceived sweetness, non-nutritive sweeteners cannot be considered super-normal stimuli. These data do not support the view that non-nutritive sweeteners hijack or over-stimulate sweet receptors to product elevated sweet sensations. PMID:24942868

Flavor-Intensity Perception: Effects of Stimulus Context

PubMed Central

Marks, Lawrence E.; Shepard, Timothy G.; Burger, Kelly; Chakwin, Emily M.

2011-01-01

Stimulus context affects judgments of intensity of both gustatory and olfactory flavors, and the contextual effects are modality-specific. Does context also exert separate effects on the gustatory and olfactory components of flavor mixtures? To answer this question, in each of 4 experiments, subjects rated the perceived intensity of 16 mixtures constructed by combining 4 concentrations of the gustatory flavorant sucrose with 4 concentrations of the retronasal olfactory flavorant citral. In 1 contextual condition of each experiment, concentrations of sucrose were relatively high and those of citral low; in the other condition, the relative concentrations of sucrose and citral reversed. There were 2 main results: First, consistent with earlier findings, in 5 of the 8 conditions, the ratings were consistent with linear addition of perceived sucrose and citral; departures from additivity appeared, however, in 3 conditions where the relative concentrations of citral were high. Second, changes in context produced contrast (adaptation-like changes) in perceived intensity: The contribution to perceived intensity of a given concentration of a flavorant was smaller when the contextual concentrations of that flavorant were high rather than low. A notable exception was the absence of contextual effects on the perceived intensity of near-threshold citral. These findings suggest that the contextual effects may arise separately in the gustatory and olfactory channels, prior to the integration of perceived flavor intensity. PMID:21930139

Production of Gymnemic Acid Depends on Medium, Explants, PGRs, Color Lights, Temperature, Photoperiod, and Sucrose Sources in Batch Culture of Gymnema sylvestre

PubMed Central

Ahmed, A. Bakrudeen Ali; Rao, A. S.; Rao, M. V.; Taha, Rosna Mat

2012-01-01

Gymnema sylvestre (R.Br.) is an important diabetic medicinal plant which yields pharmaceutically active compounds called gymnemic acid (GA). The present study describes callus induction and the subsequent batch culture optimization and GA quantification determined by linearity, precision, accuracy, and recovery. Best callus induction of GA was noticed in MS medium combined with 2,4-D (1.5 mg/L) and KN (0.5 mg/L). Evaluation and isolation of GA from the calluses derived from different plant parts, namely, leaf, stem and petioles have been done in the present case for the first time. Factors such as light, temperature, sucrose, and photoperiod were studied to observe their effect on GA production. Temperature conditions completely inhibited GA production. Out of the different sucrose concentrations tested, the highest yield (35.4 mg/g d.w) was found at 5% sucrose followed by 12 h photoperiod (26.86 mg/g d.w). Maximum GA production (58.28 mg/g d.w) was observed in blue light. The results showed that physical and chemical factors greatly influence the production of GA in callus cultures of G. sylvestre. The factors optimized for in vitro production of GA during the present study can successfully be employed for their large-scale production in bioreactors. PMID:22629221

How-to-Do-It. An Exercise in Gene Mapping.

ERIC Educational Resources Information Center

Seidel-Rogol, Bonnie L.

1990-01-01

Described is a laboratory exercise designed to introduce students to the theory and practice of gene mapping including RNA extraction, sucrose density gradient centrifugation, labelling of nucleic acids in vitro, DNA extraction, digestion of DNA with restriction enzymes, and the southern hybridization analysis. Procedures and sample results are…

DNA of a Human Hepatitis B Virus Candidate

PubMed Central

Robinson, William S.; Clayton, David A.; Greenman, Richard L.

1974-01-01

Particles containing DNA polymerase (Dane particles) were purified from the plasma of chronic carriers of hepatitis B antigen. After a DNA polymerase reaction with purified Dane particle preparations treated with Nonidet P-40 detergent, Dane particle core structures containing radioactive DNA product were isolated by sedimentation in a sucrose density gradient. The radioactive DNA was extracted with sodium dodecyl sulfate and isolated by band sedimentation in a preformed CsCl gradient. Examination of the radioactive DNA band by electron microscopy revealed exclusively circular double-stranded DNA molecules approximately 0.78 μm in length. Identical circular molecules were observed when DNA was isolated by a similar procedure from particles that had not undergone a DNA polymerase reaction. The molecules were completely degraded by DNase 1. When Dane particle core structures were treated with DNase 1 before DNA extraction, only 0.78-μm circular DNA molecules were detected. Without DNase treatment of core structures, linear molecules with lengths between 0.5 and 12 μm, in addition to the 0.78-μm circles were found. These results suggest that the 0.78-μm circular molecules were in a protected position within Dane particle cores and the linear molecules were not within core structures. Length measurements on 225 circular molecules revealed a mean length of 0.78 ± 0.09 μm which would correspond to a molecular weight of around 1.6 × 106. The circular molecules probably serve as primer-template for the DNA polymerase reaction carried out by Dane particle cores. Thermal denaturation and buoyant density measurements on the Dane particle DNA polymerase reaction product revealed a guanosine plus cytosine content of 48 to 49%. Images PMID:4847328

Fast simultaneous analysis of caffeine, trigonelline, nicotinic acid and sucrose in coffee by liquid chromatography-mass spectrometry.

PubMed

Perrone, Daniel; Donangelo, Carmen Marino; Farah, Adriana

2008-10-15

A rapid liquid chromatography-mass spectrometry method for the simultaneous quantification of caffeine, trigonelline, nicotinic acid and sucrose in coffee was developed and validated. The method involved extraction with hot water, clarification with basic lead acetate and membrane filtration, followed by chromatographic separation using a Spherisorb(®) S5 ODS2, 5μm chromatographic column and gradient elution with 0.3% aqueous formic acid/methanol at a flow rate of 0.2mL/min. The electrospray ionization source was operated in the negative mode to generate sucrose ions and in the positive mode to generate caffeine, trigonelline and nicotinic acid ions. Ionization suppression of all analytes was found due to matrix effect. Calibrations curves prepared in green and roasted coffee extracts were linear with r(2)>0.999. Roasted coffee was spiked and recoveries ranged from 93.0% to 105.1% for caffeine, from 85.2% to 116.2% for trigonelline, from 89.6% to 113.5% for nicotinic acid and from 94.1% to 109.7% for sucrose. Good repeatibilities (RSD<5%) were found for all analytes in the matrix. The limit of detection (LOD), calculated on the basis of signal-to-noise ratios of 3:1, was 11.9, 36.4, 18.5 and 5.0ng/mL for caffeine, trigonelline, nicotinic acid and sucrose, respectively. Analysis of 11 coffee samples (regular or decaffeinated green, ground roasted and instant) gave results in agreement with the literature. The method showed to be suitable for different types of coffee available in the market thus appearing as a fast and reliable alternative method to be used for routine coffee analysis. Copyright © 2008 Elsevier Ltd. All rights reserved.

Rimonabant reduces the essential value of food in the genetically obese Zucker rat: an exponential demand analysis.

PubMed

Rasmussen, Erin B; Reilly, William; Buckley, Jessica; Boomhower, Steven R

2012-02-01

Research on free-food intake suggests that cannabinoids are implicated in the regulation of feeding. Few studies, however, have characterized how environmental factors that affect food procurement interact with cannabinoid drugs that reduce food intake. Demand analysis provides a framework to understand how cannabinoid blockers, such as rimonabant, interact with effort in reducing demand for food. The present study examined the effects rimonabant had on demand for sucrose in obese Zucker rats when effort to obtain food varied and characterized the data using the exponential ("essential value") model of demand. Twenty-nine male (15 lean, 14 obese) Zucker rats lever-pressed under eight fixed ratio (FR) schedules of sucrose reinforcement, in which the number of lever-presses to gain access to a single sucrose pellet varied between 1 and 300. After behavior stabilized under each FR schedule, acute doses of rimonabant (1-10mg/kg) were administered prior to some sessions. The number of food reinforcers and responses in each condition was averaged and the exponential and linear demand equations were fit to the data. These demand equations quantify the value of a reinforcer by its sensitivity to price (FR) increases. Under vehicle conditions, obese Zucker rats consumed more sucrose pellets than leans at smaller fixed ratios; however, they were equally sensitive to price increases with both models of demand. Rimonabant dose-dependently reduced reinforcers and responses for lean and obese rats across all FR schedules. Data from the exponential analysis suggest that rimonabant dose-dependently increased elasticity, i.e., reduced the essential value of sucrose, a finding that is consistent with graphical depictions of normalized demand curves. Copyright © 2011 Elsevier Inc. All rights reserved.

Metabolic effects of aspartame in adulthood: A systematic review and meta-analysis of randomized clinical trials.

PubMed

Santos, Natalia Cardoso; de Araujo, Laiza Magalhaes; De Luca Canto, Graziela; Guerra, Eliete Neves Silva; Coelho, Michella Soares; Borin, Maria de Fatima

2017-04-10

Data about harms or benefits associated with the consumption of aspartame, a nonnutritive sweetener worldwide consumed, are still controversial. This systematic review and meta-analysis of randomized controlled clinical trials aimed to assess the effect of aspartame consumption on metabolic parameters related to diabetes and obesity. The search was performed on Cochrane, LILACS, PubMed, SCOPUS, Web of Science databases, and on a gray literature using Open Grey, Google Scholar, and ProQuest Dissertations & Theses Global. Searches across all databases were conducted from the earliest available date up to April 13, 2016, without date and language restrictions. Pooled mean differences were calculated using a random or fixed-effects model for heterogeneous and homogenous studies, respectively. Twenty-nine articles were included in qualitative synthesis and twelve, presenting numeric results, were used in meta-analysis. Fasting blood glucose (mmol/L), insulin levels (μU/mL), total cholesterol (mmol/L), triglycerides concentrations (mmol/L), high-density lipoprotein cholesterol (mmol/L), body weight (kg), and energy intake (MJ) were considered as the main outcomes in subjects that consumed aspartame, and results were presented as mean difference; % confidence interval, range. Aspartame consumption was not associated with alterations on blood glucose levels compared to control (-0.03 mmol/L; 95% CI, -0.21 to 0.14) or to sucrose (0.31 mmol/L; 95% CI, -0.05 to 0.67) and on insulin levels compared to control (0.13 μU/mL; 95% CI, -0.69 to 0.95) or to sucrose (2.54 μU/mL; 95% CI, -6.29 to 11.37). Total cholesterol was not affected by aspartame consumption compared to control (-0.02 mmol/L; 95% CI, -0.31 to 0.27) or to sucrose (-0.24 mmol/L; 95% CI, -0.89 to 0.42). Triglycerides concentrations were not affected by aspartame consumption compared to control (0.00 mmol/L; 95% CI, -0.04 to 0.05) or to sucrose (0.00 mmol/L; 95% CI, -0.09 to 0.09). High-density lipoprotein cholesterol serum levels were higher on aspartame compared to control (-0.03 mmol/L; 95% CI, -0.06 to -0.01) and lower on aspartame compared to sucrose (0.05 mmol/L; 95% CI, 0.02 to 0.09). Body weight did not change after aspartame consumption compared to control (5.00 kg; 95% CI, -1.56 to 11.56) or to sucrose (3.78 kg; 95% CI, -2.18 to 9.74). Energy intake was not altered by aspartame consumption compared to control (-0.49 MJ; 95% CI, -1.21 to 0.22) or to sucrose (-0.17 MJ; 95% CI, -2.03 to 1.69). Data concerning effects of aspartame on main metabolic variables associated to diabetes and obesity do not support a beneficial related to its consumption.

Enhanced recovery of valuable metals from spent lithium-ion batteries through optimization of organic acids produced by Aspergillus niger.

PubMed

Bahaloo-Horeh, Nazanin; Mousavi, Seyyed Mohammad

2017-02-01

In the present study, spent medium bioleaching method was performed using organic acids produced by Aspergillus niger to dissolve Ni, Co, Mn, Li, Cu and Al from spent lithium-ion batteries (LIBs). Response surface methodology was used to investigate the effects and interactions between the effective factors of sucrose concentration, initial pH, and inoculum size to optimize organic acid production. Maximum citric acid, malic acid, and gluconic acid concentrations of 26,478, 1832.53 and 8433.76ppm, respectively, and a minimum oxalic acid concentration of 305.558ppm were obtained under optimal conditions of 116.90 (gl -1 ) sucrose concentration, 3.45% (vv -1 ) inoculum size, and a pH value of 5.44. Biogenically-produced organic acids are used for leaching of spent LIBs at different pulp densities. The highest metal recovery of 100% Cu, 100% Li, 77% Mn, and 75% Al occurred at 2% (wv -1 ) pulp density; 64% Co and 54% Ni recovery occurred at 1% (wv -1 ) pulp density. The bioleaching of metals from spent LIBs can decrease the environmental impact of this waste. The results of this study suggest that the process can be used for large scale industrial purposes. Copyright © 2016 Elsevier Ltd. All rights reserved.

Gating connexin 43 channels reconstituted in lipid vesicles by mitogen-activated protein kinase phosphorylation.

PubMed

Kim, D Y; Kam, Y; Koo, S K; Joe, C O

1999-02-26

The regulation of gap junctional permeability by phosphorylation was examined in a model system in which connexin 43 (Cx43) gap junction hemichannels were reconstituted in lipid vesicles. Cx43 was immunoaffinity-purified from rat brain, and Cx43 channels were reconstituted into unilamellar phospholipid liposomes. The activities of the reconstituted channels were measured by monitoring liposome permeability. Liposomes containing the Cx43 protein were fractionated on the basis of permeability to sucrose using sedimentation in an iso-osmolar density gradient. The gradient allowed separation of the sucrose-permeable and -impermeable liposomes. Liposomes that were permeable to sucrose were also permeable to the communicating dye molecule lucifer yellow. Permeability, and therefore activity of the reconstituted Cx43 channels, were directly dependent on the state of Cx43 phosphorylation. The permeability of liposomes containing Cx43 channels was increased by treatment of liposomes with calf intestinal phosphatase. Moreover, liposomes formed with Cx43 that had been dephosphorylated by calf intestinal phosphatase treatment showed increased permeability to sucrose. The role of phosphorylation in the gating mechanism of Cx43 channels was supported further by the observation that phosphorylation of Cx43 by mitogen-activated protein kinase reversibly reduced the permeability of liposomes containing dephosphorylated Cx43. Our results show a direct correlation between gap junctional permeability and the phosphorylation state of Cx43.

Plant regeneration from leaf protoplasts of Solanum torvum.

PubMed

Guri, A; Volokita, M; Sink, K C

1987-07-01

A protocol to obtain regenerated plants from protoplasts of Solanum torvum Sw a wild species of eggplant resistant to Verticillium wilt is reported. Leaf protoplasts were enzymatically isolated from six-week old seedlings grown in a controlled environment chamber. Protoplasts were plated on modified KM medium (0.4 M glucose)+(mg/l): 1.0 p-chlorophenoxyacetic acid (CPA)+1.0 naphthaleneacetic acid (NAA)+0.5 6-benzylaminopurine (BAP) and 0.02 abscisic acid (ABA). The protoplast density was 5×10(4) per ml with 5 ml placed in each of two quadrants in X-dishes (100×15 mm). The reservoir medium was modified KM+(mg/l): 0.1 NAA+0.5 BAP+0.1 M sucrose+0.1 M mannitol+0.6% washed agar+1% activated charcoal. Dishes were initially placed in the dark at 27°C. Protoplast division was initiated in 1-2 weeks and 4 weeks later p-calli were 1-3 mm. Plating efficiency was 11% when measured at 3 weeks. Six-week old p-calli were transferred individually onto Whatman No. 1 filter paper layered on modified KM (0.15 M sucrose)+mg/l: 2.0 indoleacetic acid (IAA)+2.0 zeatin+0.5% washed agar for 2 weeks. Subsequently, shoots occurred within 4 weeks at 70% efficiency on MS+30 g/l sucrose+2 mg/l zeatin. Shoots were rooted on half strength MS+10 g/l sucrose.

The effect of normally consumed amounts of sucrose or high fructose corn syrup on lipid profiles, body composition and related parameters in overweight/obese subjects.

PubMed

Lowndes, Joshua; Sinnett, Stephanie; Pardo, Sabrina; Nguyen, Von T; Melanson, Kathleen J; Yu, Zhiping; Lowther, Britte E; Rippe, James M

2014-03-17

The American Heart Association (AHA) has advocated that women and men not consume more than 100 and 150 kcal/day, respectively, from added sugars. These levels are currently exceeded by over 90% of the adult population in the United States. Few data exist on longer-term metabolic effects when sucrose and High Fructose Corn Syrup (HFCS), the principal sources of added dietary sugars, are consumed at levels typical of the general population. Sixty five overweight and obese individuals were placed on a eucaloric (weight stable) diet for 10-weeks, which incorporated sucrose- or HFCS-sweetened, low-fat milk at 10% or 20% of calories in a randomized, double-blinded study. All groups responded similarly (interaction p > 0.05). There was no change in body weight in any of the groups over the 10-week study, or in systolic or diastolic blood pressure. Likewise, there were no changes in total cholesterol, triglycerides, low-density lipoprotein (LDL), or apolipoprotein B (Apo B). We conclude that (1) when consumed as part of a eucaloric diet fructose--when given with glucose (as normally consumed) does not promote weight gain or an atherogenic lipid profile even when consumed at two to four times the level recently recommended by the AHA. (2) There were no differences between HFCS and sucrose on these parameters.

The Effect of Normally Consumed Amounts of Sucrose or High Fructose Corn Syrup on Lipid Profiles, Body Composition and Related Parameters in Overweight/Obese Subjects

PubMed Central

Lowndes, Joshua; Sinnett, Stephanie; Pardo, Sabrina; Nguyen, Von T.; Melanson, Kathleen J.; Yu, Zhiping; Lowther, Britte E.; Rippe, James M.

2014-01-01

The American Heart Association (AHA) has advocated that women and men not consume more than 100 and 150 kcal/day, respectively, from added sugars. These levels are currently exceeded by over 90% of the adult population in the United States. Few data exist on longer-term metabolic effects when sucrose and High Fructose Corn Syrup (HFCS), the principal sources of added dietary sugars, are consumed at levels typical of the general population. Sixty five overweight and obese individuals were placed on a eucaloric (weight stable) diet for 10-weeks, which incorporated sucrose- or HFCS-sweetened, low-fat milk at 10% or 20% of calories in a randomized, double-blinded study. All groups responded similarly (interaction p > 0.05). There was no change in body weight in any of the groups over the 10-week study, or in systolic or diastolic blood pressure. Likewise, there were no changes in total cholesterol, triglycerides, low-density lipoprotein (LDL), or apolipoprotein B (Apo B). We conclude that (1) when consumed as part of a eucaloric diet fructose—when given with glucose (as normally consumed) does not promote weight gain or an atherogenic lipid profile even when consumed at two to four times the level recently recommended by the AHA. (2) There were no differences between HFCS and sucrose on these parameters. PMID:24642950

Persistence of sucrose fermenting and nonfermenting vibrios in tissues of Manila clam species, Ruditapes philippinarum, depurated in seawater at two different temperatures.

PubMed

Lopez-Joven, C; Ruiz-Zarzuela, I; de Blas, I; Furones, M D; Roque, A

2011-08-01

Effective post-harvest treatment to eliminate toxigenic vibrios is an important measure to reduce risk associated with seafood consumption. In the present study, we examined whether natural populations of sucrose nonfermenting (SNFV) and sucrose fermenting vibrios (SFV) persisted in Ruditapes philippinarum, after depuration at two different temperatures. Two experiments (one in Spring and one in Summer) were performed. Clams were depurated in duplicate tanks in an open-circuit seawater system using filtration and ultraviolet treatment. Clams were sampled daily (9 days), individually processed and inoculated on thiosulphate-citrate-bile salts-sucrose (TCBS) agar plates to estimate the density of SNFV and SFV. Results showed that depuration was less effective in Summer than in Spring, for SNFV and SFV. Despite an initial lower presence in the Summer experiment, clearance of SNFV was less efficient than in Spring, with 22.2% of clams presenting SNFV on day 8 and without significant changes on day 9. When compared, daily proportion of presence of SNFV and SFV in Spring, it was observed that SFV were more frequent than SNFV on days 8 and 9. In Summer these differences were significant on days 7-9. Present study demonstrated that SNFV (involved in food poisoning) are purged, at any temperature, faster than SFV. Copyright © 2011 Elsevier Ltd. All rights reserved.

ISOLATION OF SMOOTH VESICLES AND FREE RIBOSOMES FROM RAT LIVER MICROSOMES

PubMed Central

Chauveau, J.; Moulé, Y.; Rouiller, C.; Schneebeli, J.

1962-01-01

Microsomes, isolated from rat liver homogenate in 0.88 M sucrose, have been fractionated by differential centrifugation. The 2nd microsomal fraction, sedimented between 60 minutes at 105,000 g and 3 hours at 145,000 g, consists mainly of smooth vesicles, free ribosomes, and ferritin. By utilizing the differences in density existing between the membranes and the granular elements it has been possible to separate the smooth membranes from the free ribosomes and ferritin. The procedure is to resuspend the 2nd microsomal fraction in a sucrose solution of 1.21 or 1.25 density and centrifuge it at 145,000 g for 20 or 40 hours. A centripetal migration of membranes and a centrifugal sedimentation of granular elements are obtained. Phospholipids, as well as the enzymatic activities DPNH-cytochrome c reductase, glucose-6-phosphatase and esterase are localized in the membranes. The free ribosomes have been purified by washing. A concentration of 200 µg RNA per mg nitrogen has been reached. RNA is also present in the membranes. These results are discussed in relation to current views on microsomal structure and chemistry. PMID:13878497

Food restriction-induced hyperactivity: addiction or adaptation to famine?

PubMed

Duclos, Martine; Ouerdani, Amel; Mormède, Pierre; Konsman, Jan Pieter

2013-06-01

Increased physical activity is present in 30-80% of anorexia nervosa patients. To explain the paradox of low food intake and excessive exercise in humans and other animals, it has been proposed that increased physical activity along with food restriction activates brain reward circuits and is addictive. Alternatively, the fleeing-famine hypothesis postulates that refusal of known scarce energy-low food sources and hyperactivity facilitate migration towards new habitats that potentially contain new energy-rich foodstuffs. The use of rewarding compounds that differ in energy density, such as the energy-free sweetener saccharin and the energy rich sucrose makes it possible to critically test the reward-addiction and fleeing-famine hypotheses. The aims of the present work were to study if sucrose and/or saccharin could attenuate food restriction-induced hyperactivity, weight loss, increased plasma corticosterone, and activation of brain structures involved in neuroendocrine control, energy balance, physical activity, and reward signaling in rats. Its major findings are that access to sucrose, but not to saccharin, attenuated food restriction-induced running wheel activity, weight loss, rises in plasma corticosterone, and expression of the cellular activation marker c-Fos in the paraventricular and arcuate hypothalamus and in the nucleus accumbens. These findings suggest that the energy-richness and easy availability of sucrose interrupted a fleeing-famine-like hyperactivity response. Since corticosterone mediates food restriction-induced wheel running (Duclos et al., 2009), we propose that the attenuating effect of sucrose consumption on plasma corticosterone plays a role in reduced wheel running and weight loss by lowering activation of the nucleus accumbens and arcuate hypothalamus in these animals. Copyright © 2012 Elsevier Ltd. All rights reserved.

Rimonabant’s Reductive Effects on High Densities of Food Reinforcement, but not Palatability, in Lean and Obese Zucker Rats

PubMed Central

Buckley, Jessica Lynn; Rasmussen, Erin B.

2014-01-01

Rationale Cannabinoid antagonists purportedly have greater effects in reducing the intake of highly palatable food compared to less palatable food. However, this assertion is based on free-feeding studies in which the amount of palatable food eaten under baseline conditions is often confounded with other variables, such as unequal access to both food options and differences in qualitative features of the foods. Objective We attempted to reduce these confounds by using a model of choice that programmed the delivery rates of sucrose and carrot-flavored pellets. Methods Lever-pressing of ten lean (Fa/Fa or Fa/fa) and ten obese (fa/fa) Zucker rats was placed under three conditions in which programmed ratios for food pellets on two levers were 5:1, 1:1, and 1:5. In Phase 1, responses on the two levers produced one type of pellet (sucrose or carrot); in Phase 2, responses on one lever produced sucrose pellets and on the other lever produced carrot pellets. After responses stabilized under each food ratio, acute doses of rimonabant (0, 3, and 10 mg/kg) were administered before experimental sessions. The number of reinforcers and responses earned per session under each ratio and from each lever was compared. Results and Conclusions Rimonabant reduced reinforcers in 1:5 and 5:1 food ratios in Phase 1, and across all ratios in Phase 2. Rimonabant reduced sucrose and carrot-flavored pellet consumption similarly; rimonabant did not affect bias toward sucrose, but increased sensitivity to amount differences in lean rats. This suggests that relative amount of food, not palatability, may be an important behavioral mechanism in the effects of rimonabant. PMID:24398820

Rimonabant's reductive effects on high densities of food reinforcement, but not palatability, in lean and obese Zucker rats.

PubMed

Buckley, Jessica L; Rasmussen, Erin B

2014-05-01

Cannabinoid antagonists purportedly have greater effects in reducing the intake of highly palatable food compared to less palatable food. However, this assertion is based on free-feeding studies in which the amount of palatable food eaten under baseline conditions is often confounded with other variables, such as unequal access to both food options and differences in qualitative features of the foods. We attempted to reduce these confounds by using a model of choice that programmed the delivery rates of sucrose and carrot-flavored pellets. Lever pressing of ten lean (Fa/Fa or Fa/fa) and ten obese (fa/fa) Zucker rats was placed under three conditions in which programmed ratios for food pellets on two levers were 5:1, 1:1, and 1:5. In phase 1, responses on the two levers produced one type of pellet (sucrose or carrot); in phase 2, responses on one lever produced sucrose pellets and on the other lever produced carrot pellets. After responses stabilized under each food ratio, acute doses of rimonabant (0, 3, and 10 mg/kg) were administered before experimental sessions. The number of reinforcers and responses earned per session under each ratio and from each lever was compared. Rimonabant reduced reinforcers in 1:5 and 5:1 food ratios in phase 1, and across all ratios in phase 2. Rimonabant reduced sucrose and carrot-flavored pellet consumption similarly; rimonabant did not affect bias toward sucrose, but increased sensitivity to amount differences in lean rats. This suggests that relative amount of food, not palatability, may be an important behavioral mechanism in the effects of rimonabant.

The in planta transcriptome of Ralstonia solanacearum: conserved physiological and virulence strategies during bacterial wilt of tomato.

PubMed

Jacobs, Jonathan M; Babujee, Lavanya; Meng, Fanhong; Milling, Annett; Allen, Caitilyn

2012-01-01

Plant xylem fluid is considered a nutrient-poor environment, but the bacterial wilt pathogen Ralstonia solanacearum is well adapted to it, growing to 10(8) to 10(9) CFU/g tomato stem. To better understand how R. solanacearum succeeds in this habitat, we analyzed the transcriptomes of two phylogenetically distinct R. solanacearum strains that both wilt tomato, strains UW551 (phylotype II) and GMI1000 (phylotype I). We profiled bacterial gene expression at ~6 × 10(8) CFU/ml in culture or in plant xylem during early tomato bacterial wilt pathogenesis. Despite phylogenetic differences, these two strains expressed their 3,477 common orthologous genes in generally similar patterns, with about 12% of their transcriptomes significantly altered in planta versus in rich medium. Several primary metabolic pathways were highly expressed during pathogenesis. These pathways included sucrose uptake and catabolism, and components of these pathways were encoded by genes in the scrABY cluster. A UW551 scrA mutant was significantly reduced in virulence on resistant and susceptible tomato as well as on potato and the epidemiologically important weed host Solanum dulcamara. Functional scrA contributed to pathogen competitive fitness during colonization of tomato xylem, which contained ~300 µM sucrose. scrA expression was induced by sucrose, but to a much greater degree by growth in planta. Unexpectedly, 45% of the genes directly regulated by HrpB, the transcriptional activator of the type 3 secretion system (T3SS), were upregulated in planta at high cell densities. This result modifies a regulatory model based on bacterial behavior in culture, where this key virulence factor is repressed at high cell densities. The active transcription of these genes in wilting plants suggests that T3SS has a biological role throughout the disease cycle. IMPORTANCE Ralstonia solanacearum is a widespread plant pathogen that causes bacterial wilt disease. It inflicts serious crop losses on tropical farmers, with major economic and human consequences. It is also a model for the many destructive microbes that colonize the water-conducting plant xylem tissue, which is low in nutrients and oxygen. We extracted bacteria from infected tomato plants and globally identified the biological functions that R. solanacearum expresses during plant pathogenesis. This revealed the unexpected presence of sucrose in tomato xylem fluid and the pathogen's dependence on host sucrose for virulence on tomato, potato, and the common weed bittersweet nightshade. Further, R. solanacearum was highly responsive to the plant environment, expressing several metabolic and virulence functions quite differently in the plant than in pure culture. These results reinforce the utility of studying pathogens in interaction with hosts and suggest that selecting for reduced sucrose levels could generate wilt-resistant crops.

Natural honey lowers plasma glucose, C-reactive protein, homocysteine, and blood lipids in healthy, diabetic, and hyperlipidemic subjects: comparison with dextrose and sucrose.

PubMed

Al-Waili, Noori S

2004-01-01

This study included the following experiments: (1) effects of dextrose solution (250 mL of water containing 75 g of dextrose) or honey solution (250 mL of water containing 75 g of natural honey) on plasma glucose level (PGL), plasma insulin, and plasma C-peptide (eight subjects); (2) effects of dextrose, honey, or artificial honey (250 mL of water containing 35 g of dextrose and 40 g of fructose) on cholesterol and triglycerides (TG) (nine subjects); (3) effects of honey solution, administered for 15 days, on PGL, blood lipids, C-reactive protein (CRP), and homocysteine (eight subjects); (4) effects of honey or artificial honey on cholesterol and TG in six patients with hypercholesterolemia and five patients with hypertriglyceridemia; (5) effects of honey for 15 days on blood lipid and CRP in five patients with elevated cholesterol and CRP; (6) effects of 70 g of dextrose or 90 g of honey on PGL in seven patients with type 2 diabetes mellitus; and (7) effects of 30 g of sucrose or 30 g of honey on PGL, plasma insulin, and plasma C-peptide in five diabetic patients. In healthy subjects, dextrose elevated PGL at 1 (53%) and 2 (3%) hours, and decreased PGL after 3 hours (20%). Honey elevated PGL after 1 hour (14%) and decreased it after 3 hours (10%). Elevation of insulin and C-peptide was significantly higher after dextrose than after honey. Dextrose slightly reduced cholesterol and low-density lipoprotein-cholesterol (LDL-C) after 1 hour and significantly after 2 hours, and increased TG after 1, 2, and 3 hours. Artificial honey slightly decreased cholesterol and LDL-C and elevated TG. Honey reduced cholesterol, LDL-C, and TG and slightly elevated high-density lipoprotein-cholesterol (HDL-C). Honey consumed for 15 days decreased cholesterol (7%), LDL-C (1%), TG (2%), CRP (7%), homocysteine (6%), and PGL (6%), and increased HDL-C (2%). In patients with hypertriglyceridemia, artificial honey increased TG, while honey decreased TG. In patients with hyperlipidemia, artificial honey increased LDL-C, while honey decreased LDL-C. Honey decreased cholesterol (8%), LDL-C (11%), and CRP (75%) after 15 days. In diabetic patients, honey compared with dextrose caused a significantly lower rise of PGL. Elevation of PGL was greater after honey than after sucrose at 30 minutes, and was lower after honey than it was after sucrose at 60, 120, and 180 minutes. Honey caused greater elevation of insulin than sucrose did after 30, 120, and 180 minutes. Honey reduces blood lipids, homocysteine, and CRP in normal and hyperlipidemic subjects. Honey compared with dextrose and sucrose caused lower elevation of PGL in diabetics.

Preliminary Assessment of Various Additives on the Specific Reactivity of Anti- rHBsAg Monoclonal Antibodies

PubMed Central

Yazdani, Yaghoub; Mohammadi, Saeed; Yousefi, Mehdi; Shokri, Fazel

2015-01-01

Background: Antibodies have a wide application in diagnosis and treatment. In order to maintain optimal stability of various functional parts of antibodies such as antigen binding sites, several approaches have been suggested. Using additives such as polysaccharides and polyols is one of the main methods in protecting antibodies against aggregation or degradation in the formulation. The aim of this study was to evaluate the protective effect of various additives on the specific reactivity of monoclonal antibodies (mAbs) against recombinant HBsAg (rHBsAg) epitopes. Methods: To estimate the protective effect of different additives on the stability of antibody against conformational epitopes (S3 antibody) and linear epitopes (S7 and S11 antibodies) of rHBsAg, heat shock at 37°C was performed in liquid and solid phases. Environmental factors were considered to be constant. The specific reactivity of antibodies was evaluated using ELISA method. The data were analyzed using SPSS software by Mann-Whitney nonparametric test with the confidence interval of 95%. Results: Our results showed that 0.25 M sucrose, 0.04 M trehalose and 0.5% BSA had the most protective effect on maintaining the reactivity of mAbs (S3) against conformational epitopes of rHBsAg. Results obtained from S7 and S11 mAbs against linear characteristics showed minor differences. The most efficient protective additives were 0.04 M trehalose and 1 M sucrose. Conclusion: Nowadays, application of appropriate additives is important for increasing the stability of antibodies. It was concluded that sucrose, trehalose and BSA have considerable effects on the specific reactivity of anti rHBsAg mAbs during long storage. PMID:26605008

Preliminary Assessment of Various Additives on the Specific Reactivity of Anti- rHBsAg Monoclonal Antibodies.

PubMed

Yazdani, Yaghoub; Mohammadi, Saeed; Yousefi, Mehdi; Shokri, Fazel

2015-01-01

Antibodies have a wide application in diagnosis and treatment. In order to maintain optimal stability of various functional parts of antibodies such as antigen binding sites, several approaches have been suggested. Using additives such as polysaccharides and polyols is one of the main methods in protecting antibodies against aggregation or degradation in the formulation. The aim of this study was to evaluate the protective effect of various additives on the specific reactivity of monoclonal antibodies (mAbs) against recombinant HBsAg (rHBsAg) epitopes. To estimate the protective effect of different additives on the stability of antibody against conformational epitopes (S3 antibody) and linear epitopes (S7 and S11 antibodies) of rHBsAg, heat shock at 37°C was performed in liquid and solid phases. Environmental factors were considered to be constant. The specific reactivity of antibodies was evaluated using ELISA method. The data were analyzed using SPSS software by Mann-Whitney nonparametric test with the confidence interval of 95%. Our results showed that 0.25 M sucrose, 0.04 M trehalose and 0.5% BSA had the most protective effect on maintaining the reactivity of mAbs (S3) against conformational epitopes of rHBsAg. Results obtained from S7 and S11 mAbs against linear characteristics showed minor differences. The most efficient protective additives were 0.04 M trehalose and 1 M sucrose. Nowadays, application of appropriate additives is important for increasing the stability of antibodies. It was concluded that sucrose, trehalose and BSA have considerable effects on the specific reactivity of anti rHBsAg mAbs during long storage.

Invisible liposomes: refractive index matching with sucrose enables flow dichroism assessment of peptide orientation in lipid vesicle membrane.

PubMed

Ardhammar, Malin; Lincoln, Per; Nordén, Bengt

2002-11-26

Valuable information on protein-membrane organization may in principle be obtained from polarized-light absorption (linear dichroism, LD) measurement on shear-aligned lipid vesicle bilayers as model membranes. However, attempts to probe LD in the UV wavelength region (<250 nm) have so far failed because of strong polarized light scattering from the vesicles. Using sucrose to match the refractive index and suppress the light scattering of phosphatidylcholine vesicles, we have been able to detect LD bands also in the peptide-absorbing region (200-230 nm). The potential of refractive index matching in vesicle LD as a general method for studying membrane protein structure was investigated for the membrane pore-forming oligopeptide gramicidin incorporated into the liposome membranes. In the presence of sucrose, the LD signals arising from oriented tryptophan side chains as well as from n-->pi* and pi-->pi* transitions of the amide chromophore of the polypeptide backbone could be studied. The observation of a strongly negative LD for the first exciton transition ( approximately 204 nm) is consistent with a membrane-spanning orientation of two intertwined parallel gramicidin helices, as predicted by coupled-oscillator theory.

Calmodulin stimulation of calcium transport in carrot microsomal vesicles. [Daucus carota

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pierce, W.S.; Sze, H.

1987-04-01

ATP-dependent /sup 45/Ca/sup 2 +/ uptake into microsomal vesicles isolated from cultured carrot cells (Daucus carota Danvers) was stimulated 2-3 fold by 5 ug/ml calmodulin (CaM). Microsomal vesicles separated with a linear sucrose gradient showed two peaks with CaM-stimulated Ca/sup 2 +/ uptake activities. One peak (at 1.12 g/cc) comigrated with the activity of the antimycin A-insensitive NADH-dependent cytochrome c reductase. This transport activity was enhanced 10-20 fold by 10 mM oxalate and appeared to be associates with vesicles derived primarily from the ER. The other peak of CaM-stimulated Ca/sup 2 +/ uptake (at 1.17 g/cc) was not affected bymore » oxalate. These vesicles are probably derived from the plasma membrane. Preliminary experiments with the low-density vesicles (ER) vesicles, indicate that inositol-1,4,5-trisphosphate caused a transient reduction in intravesicular Ca/sup 2 +/. These results are consistent with the ER being an important site of intracellular Ca/sup 2 +/ regulation.« less

Prediction of solubility parameters and miscibility of pharmaceutical compounds by molecular dynamics simulations.

PubMed

Gupta, Jasmine; Nunes, Cletus; Vyas, Shyam; Jonnalagadda, Sriramakamal

2011-03-10

The objectives of this study were (i) to develop a computational model based on molecular dynamics technique to predict the miscibility of indomethacin in carriers (polyethylene oxide, glucose, and sucrose) and (ii) to experimentally verify the in silico predictions by characterizing the drug-carrier mixtures using thermoanalytical techniques. Molecular dynamics (MD) simulations were performed using the COMPASS force field, and the cohesive energy density and the solubility parameters were determined for the model compounds. The magnitude of difference in the solubility parameters of drug and carrier is indicative of their miscibility. The MD simulations predicted indomethacin to be miscible with polyethylene oxide and to be borderline miscible with sucrose and immiscible with glucose. The solubility parameter values obtained using the MD simulations values were in reasonable agreement with those calculated using group contribution methods. Differential scanning calorimetry showed melting point depression of polyethylene oxide with increasing levels of indomethacin accompanied by peak broadening, confirming miscibility. In contrast, thermal analysis of blends of indomethacin with sucrose and glucose verified general immiscibility. The findings demonstrate that molecular modeling is a powerful technique for determining the solubility parameters and predicting miscibility of pharmaceutical compounds. © 2011 American Chemical Society

Three-Dimensional Printed Graphene Foams.

PubMed

Sha, Junwei; Li, Yilun; Villegas Salvatierra, Rodrigo; Wang, Tuo; Dong, Pei; Ji, Yongsung; Lee, Seoung-Ki; Zhang, Chenhao; Zhang, Jibo; Smith, Robert H; Ajayan, Pulickel M; Lou, Jun; Zhao, Naiqin; Tour, James M

2017-07-25

An automated metal powder three-dimensional (3D) printing method for in situ synthesis of free-standing 3D graphene foams (GFs) was successfully modeled by manually placing a mixture of Ni and sucrose onto a platform and then using a commercial CO 2 laser to convert the Ni/sucrose mixture into 3D GFs. The sucrose acted as the solid carbon source for graphene, and the sintered Ni metal acted as the catalyst and template for graphene growth. This simple and efficient method combines powder metallurgy templating with 3D printing techniques and enables direct in situ 3D printing of GFs with no high-temperature furnace or lengthy growth process required. The 3D printed GFs show high-porosity (∼99.3%), low-density (∼0.015g cm -3 ), high-quality, and multilayered graphene features. The GFs have an electrical conductivity of ∼8.7 S cm -1 , a remarkable storage modulus of ∼11 kPa, and a high damping capacity of ∼0.06. These excellent physical properties of 3D printed GFs indicate potential applications in fields requiring rapid design and manufacturing of 3D carbon materials, for example, energy storage devices, damping materials, and sound absorption.

Simultaneous separation and determination of fructose, sorbitol, glucose and sucrose in fruits by HPLC-ELSD.

PubMed

Ma, Chunmei; Sun, Zhen; Chen, Changbao; Zhang, Lili; Zhu, Shuhua

2014-02-15

A high-performance liquid chromatography (HPLC) method with evaporative light scattering detection (ELSD) was optimised for simultaneous determination of fructose, sorbitol, glucose and sucrose in fruits. The analysis was carried out on a Phenomenex Luna 5u NH₂ 100A column (250 mm × 4.60mm, 5 micron) with isocratic elution of acetonitrile:water (82.5:17.5, v/v). Drift tube temperature of the ELSD system was set to 82 °C and nitrogen flow rate was 2.0 L min⁻¹. The regression equation revealed good linear relationship (R = 0.9967-0.9989) within test ranges. The limits of detection (LOD) and quantification (LOQ) for four analytes (peach, apple, watermelon, and cherry fruits) were in the range of 0.07-0.27 and 0.22-0.91 mg L⁻¹, respectively. The proposed HPLC-ELSD method was validated for quantification of sugars in peach, apple, watermelon, and cherry fruits, and the results were satisfactory. The results showed that the contents of the four sugars varied among fruits. While fructose (5.79-104.01 mg g⁻¹) and glucose (9.25-99.62 mg g⁻¹) emerged as common sugars in the four fruits, sorbitol (8.70-19.13 mg g⁻¹) were only found in peach, apple and cherry fruits, and sucrose (15.82-106.39 mg g⁻¹) were in peach, apple and watermelon. There was not detectable sorbitol in watermelon and sucrose in cherry fruits, respectively. Copyright © 2013 Elsevier Ltd. All rights reserved.

Characterization of a dielectric phantom for high-field magnetic resonance imaging applications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Duan, Qi, E-mail: Qi.Duan@nih.gov; Duyn, Jeff H.; Gudino, Natalia

2014-10-15

Purpose: In this work, a generic recipe for an inexpensive and nontoxic phantom was developed within a range of biologically relevant dielectric properties from 150 MHz to 4.5 GHz. Methods: The recipe includes deionized water as the solvent, NaCl to primarily control conductivity, sucrose to primarily control permittivity, agar–agar to gel the solution and reduce heat diffusivity, and benzoic acid to preserve the gel. Two hundred and seventeen samples were prepared to cover the feasible range of NaCl and sucrose concentrations. Their dielectric properties were measured using a commercial dielectric probe and were fitted to a 3D polynomial to generatemore » a recipe describing the properties as a function of NaCl concentration, sucrose concentration, and frequency. Results: Results indicated that the intuitive linear and independent relationships between NaCl and conductivity and between sucrose and permittivity are not valid. A generic polynomial recipe was developed to characterize the complex relationship between the solutes and the resulting dielectric values and has been made publicly available as a web application. In representative mixtures developed to mimic brain and muscle tissue, less than 2% difference was observed between the predicted and measured conductivity and permittivity values. Conclusions: It is expected that the recipe will be useful for generating dielectric phantoms for general magnetic resonance imaging (MRI) coil development at high magnetic field strength, including coil safety evaluation as well as pulse sequence evaluation (including B{sub 1}{sup +} mapping, B{sub 1}{sup +} shimming, and selective excitation pulse design), and other non-MRI applications which require biologically equivalent dielectric properties.« less

Mimicking lichens: incorporation of yeast strains together with sucrose-secreting cyanobacteria improves survival, growth, ROS removal, and lipid production in a stable mutualistic co-culture production platform

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Tingting; Li, Chien-Ting; Butler, Kirk

The feasibility of heterotrophic-phototrophic symbioses was tested via pairing of yeast strains Cryptococcus curvatus, Rhodotorula glutinis, or Saccharomyces cerevisiae with a sucrose-secreting cyanobacterium Synechococcus elongatus. The phototroph S. elongatus showed no growth in standard BG-11 medium with yeast extract, but grew well in BG-11 medium alone or supplemented with yeast nitrogen base without amino acids (YNB w/o aa). Among three yeast species, C. curvatus and R. glutinis adapted well to the BG-11 medium supplemented with YNB w/o aa, sucrose, and various concentrations of NaCl needed to maintain sucrose secretion from S. elongatus, while growth of S. cerevisiae was highly dependentmore » on sucrose levels. R. glutinis and C. curvatus grew efficiently and utilized sucrose produced by the partner in co-culture. Co-cultures of S. elongatus and R. glutinis were sustained over 1 month in both batch and in semi-continuous culture, with the final biomass and overall lipid yields in the batch co-culture 40 to 60% higher compared to batch mono-cultures of S. elongatus. The co-cultures showed enhanced levels of palmitoleic and linoleic acids. Furthermore, cyanobacterial growth in co-culture with R. glutinis was significantly superior to axenic growth, as S. elongatus was unable to grow in the absence of the yeast partner when cultivated at lower densities in liquid medium. Accumulated reactive oxygen species was observed to severely inhibit axenic growth of cyanobacteria, which was efficiently alleviated through catalase supply and even more effectively with co-cultures of R. glutinis. In conclusion, the pairing of a cyanobacterium and eukaryotic heterotroph in the artificial lichen of this study demonstrates the importance of mutual interactions between phototrophs and heterotrophs, e.g., phototrophs provide a carbon source to heterotrophs, and heterotrophs assist phototrophic growth and survival by removing/eliminating oxidative stress. Our results establish a potential stable production platform that combines the metabolic capability of photoautotrophs to capture inorganic carbon with the channeling of the resulting organic carbon directly to a robust heterotroph partner for producing biofuel and other chemical precursors.« less

Mimicking lichens: incorporation of yeast strains together with sucrose-secreting cyanobacteria improves survival, growth, ROS removal, and lipid production in a stable mutualistic co-culture production platform

DOE PAGES

Li, Tingting; Li, Chien-Ting; Butler, Kirk; ...

2017-03-21

The feasibility of heterotrophic-phototrophic symbioses was tested via pairing of yeast strains Cryptococcus curvatus, Rhodotorula glutinis, or Saccharomyces cerevisiae with a sucrose-secreting cyanobacterium Synechococcus elongatus. The phototroph S. elongatus showed no growth in standard BG-11 medium with yeast extract, but grew well in BG-11 medium alone or supplemented with yeast nitrogen base without amino acids (YNB w/o aa). Among three yeast species, C. curvatus and R. glutinis adapted well to the BG-11 medium supplemented with YNB w/o aa, sucrose, and various concentrations of NaCl needed to maintain sucrose secretion from S. elongatus, while growth of S. cerevisiae was highly dependentmore » on sucrose levels. R. glutinis and C. curvatus grew efficiently and utilized sucrose produced by the partner in co-culture. Co-cultures of S. elongatus and R. glutinis were sustained over 1 month in both batch and in semi-continuous culture, with the final biomass and overall lipid yields in the batch co-culture 40 to 60% higher compared to batch mono-cultures of S. elongatus. The co-cultures showed enhanced levels of palmitoleic and linoleic acids. Furthermore, cyanobacterial growth in co-culture with R. glutinis was significantly superior to axenic growth, as S. elongatus was unable to grow in the absence of the yeast partner when cultivated at lower densities in liquid medium. Accumulated reactive oxygen species was observed to severely inhibit axenic growth of cyanobacteria, which was efficiently alleviated through catalase supply and even more effectively with co-cultures of R. glutinis. In conclusion, the pairing of a cyanobacterium and eukaryotic heterotroph in the artificial lichen of this study demonstrates the importance of mutual interactions between phototrophs and heterotrophs, e.g., phototrophs provide a carbon source to heterotrophs, and heterotrophs assist phototrophic growth and survival by removing/eliminating oxidative stress. Our results establish a potential stable production platform that combines the metabolic capability of photoautotrophs to capture inorganic carbon with the channeling of the resulting organic carbon directly to a robust heterotroph partner for producing biofuel and other chemical precursors.« less

Sucralose Destabilization of Protein Structure.

PubMed

Chen, Lee; Shukla, Nimesh; Cho, Inha; Cohn, Erin; Taylor, Erika A; Othon, Christina M

2015-04-16

Sucralose is a commonly employed artificial sweetener that behaves very differently than its natural disaccharide counterpart, sucrose, in terms of its interaction with biomolecules. The presence of sucralose in solution is found to destabilize the native structure of two model protein systems: the globular protein bovine serum albumin and an enzyme staphylococcal nuclease. The melting temperature of these proteins decreases as a linear function of sucralose concentration. We correlate this destabilization to the increased polarity of the molecule. The strongly polar nature is manifested as a large dielectric friction exerted on the excited-state rotational diffusion of tryptophan using time-resolved fluorescence anisotropy. Tryptophan exhibits rotational diffusion proportional to the measured bulk viscosity for sucrose solutions over a wide range of concentrations, consistent with a Stokes-Einstein model. For sucralose solutions, however, the diffusion is dependent on the concentration, strongly diverging from the viscosity predictions, and results in heterogeneous rotational diffusion.

A model for melanosome biogenesis based on the purification and analysis of early melanosomes

PubMed Central

Kushimoto, Tsuneto; Basrur, Venkatesha; Valencia, Julio; Matsunaga, Jun; Vieira, Wilfred D.; Ferrans, Victor J.; Muller, Jacqueline; Appella, Ettore; Hearing, Vincent J.

2001-01-01

Melanosome biogenesis and function were studied after purification of early stage melanosomes and characterization of specific proteins sorted to that organelle. Melanosomes were isolated from highly pigmented human MNT1 melanoma cells after disruption and initial separation by sucrose density gradient centrifugation. Low-density sucrose fractions were found by electron microscopy to be enriched in stage I and stage II melanosomes, and these fractions were further separated and purified by free flow electrophoresis. Tyrosinase and dopachrome tautomerase (DCT) activities were found exclusively in stage II melanosomes, even though DCT (and to some extent tyrosinase) proteins were sorted to stage I melanosomes. Western immunoblotting revealed that these catalytic proteins, as well as TYRP1, MART1, and GP100, were cleaved and inactivated in stage I melanosomes. Proteolytic cleavage was critical for the refolding of GP100 within the melanosomal milieu, and subsequent reorganization of amorphous stage I melanosomes into fibrillar, ovoid, and highly organized stage II melanosomes appears to stabilize the catalytic functions of melanosomal enzymes and allows melanin biosynthesis to begin. These results provide a better understanding of the structural features seen during melanosome biogenesis, and they yield further clues as to the physiological regulation of pigmentation. PMID:11526213

Brain regions mediating α3β4 nicotinic antagonist effects of 18-MC on methamphetamine and sucrose self-administration

PubMed Central

Glick, Stanley D.; Sell, Elizabeth M.; Maisonneuve, Isabelle M.

2008-01-01

The novel iboga alkaloid congener 18-methoxycoronaridine (18-MC) is a putative anti-addictive agent that has been shown, in rats, to decrease the self-administration of several drugs of abuse. Previous work has established that 18-MC is a potent antagonist at α3β4 nicotinic receptors. Because high densities of α3β4 nicotinic receptors occur in the medial habenula and the interpeduncular nucleus and moderate densities occur in the dorsolateral tegmentum, ventral tegmental area, and basolateral amygdala, the present study was conducted to determine if 18-MC could act in these brain areas to modulate methamphetamine self-administration in rats. Local administration of 18-MC into either the medial habenula, the interpeduncular area or the basolateral amygdala decreased methamphetamine self-administration. Similar results were produced by local administration into the same brain areas of two other α3β4 nicotinic antagonists, mecamylamine and α-conotoxin AuIB. Local administration of 18-MC, or the other antagonists, into the dorsolateral tegmentum or the ventral tegmental area had no effect on methamphetamine self-administration. In contrast, local administration of 18-MC and the other antagonists decreased sucrose self-administration when administered into the dorsolateral tegmentum or basolateral amygdala but had no effect when infused into the medial habenula, interpeduncular nucleus, or ventral tegmental area. These data are consistent with the hypothesis that 18-MC decreases methamphetamine self-administration by indirectly modulating the dopaminergic mesolimbic pathway via blockade of α3β4 nicotinic receptors in the habenulo-interpeduncular pathway and the basolateral amygdala. The data also suggest that the basolateral amygdala along with a different pathway involving α3β4 receptors in the dorsolateral tegmentum mediate the effect of 18-MC on sucrose self-administration. PMID:18930043

FT-MIR supported Electrical Impedance Spectroscopy based study of sugar adulterated honeys from different floral origin.

PubMed

Das, Chirantan; Chakraborty, Subhadip; Acharya, Krishnendu; Bera, Nirmal Kumar; Chattopadhyay, Dipankar; Karmakar, Anupam; Chattopadhyay, Sanatan

2017-08-15

This study sought to detect the presence of sucrose as an adulterant in selected honey varieties from different floral origins by employing Electrical Impedance Spectroscopy (EIS) technique which has been simultaneously supported by Fourier Transform-Mid Infrared Spectroscopy (FT-MIR) measurements to provide a rapid, robust yet simple platform for honey quality evaluation. Variation of electrical parameters such as impedance, capacitance and conductance for 10%, 20%, 30%, 40%, 50%, 60% and 70% (w/w) sucrose syrup (SS) adulterated honey samples are analyzed and their respective current-voltage (I-V) characteristics are studied. Capacitance, conductance and net current flowing through the system are observed to decrease linearly whereas system impedance has been found to increase similarly with the increase in adulterant content. Also, FT-MIR measurements in the spectral region between 1800cm -1 and 650cm -1 reveal the increment of absorbance values due to the addition of SS. Full-Width-at-Half-Maximum (FWHM) is estimated from the spectral peak 1056cm -1 for all pure and adulterated honey samples and is observed to be linearly increasing with increase in adulterant content. Finally, the coefficient of sensitivity has been extracted for all varieties of honey considered in terms of the measured conductance values. Copyright © 2017 Elsevier B.V. All rights reserved.

A novel technique for determination of the fructose, glucose and sucrose distribution in nectar from orchids by HPLC-ELSD.

PubMed

Lindqvist, Dan Nybro; Pedersen, Henrik Ærenlund; Rasmussen, Lars Holm

2018-04-01

The dominant components in floral nectar is fructose, glucose and sucrose. The concentration and the ratio between the sugars are indicative for plant species and play an important part in the interplay between plants and pollinators. In this paper we present a novel HPLC-ELSD based analytical method for sugar characterization of nectar from orchids. Nectar was collected on Whatman No. 1 paper and preserved in the field by 70 v/v% ethanol. The analytical method had a linear range up to at least 3000 mg L -1 for all 3 sugars with a precision of 1.5-1.7%. Correlation coefficients were 0.9999 to 1.0000. The LOD of all sugars were 5-7 mg L -1 and the LOQ were 17-19 mg L -1 . Field samples were stable for min. 7 weeks at -18 °C. The technique was applied to two species of Platanthera (Orchidaceae) in order to test whether species-related differences in sugar composition could be observed. No differences were found between the two species, which were sucrose-dominant (53.5-100%) though with high variation within species and between individual flowers. Copyright © 2018 Elsevier B.V. All rights reserved.

Sucrose-mediated transcriptional regulation of sucrose symporter activity in the phloem.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Matt Vaughn Greg Harrington Daniel R Bush

2002-08-06

This project was based on our discovery that sucrose acts as a signaling molecule that regulates the activity of a proton-sucrose symporter in sugar beet leaf tissue. A major objective here was determining how sucrose transporter activity is being regulated. When sucrose accumulates in the phloem sucrose transport activity drops dramatically. Western blots of plasma membrane proteins isolated from sucrose treated leaves showed that the loss of sucrose transport activity was proportional to a decline in symporter abundance, demonstrating that sucrose transport is regulated by changes in the amount of BvSUT1 protein. BvSUT1 transcript levels decreased in parallel with themore » loss of sucrose transport activity. Nuclear run-on experiments demonstrated that BvSUT1 gene transcription was repressed significantly in nuclei from leaves fed 100 mM exogenous sucrose, showing that sucrose-dependent modulation of BvSUT1 mRNA levels is mediated by changes in transcription. To identify which secondary messenger systems might be involved in regulating symporter activity, we used a variety of pharmacological agents to probe for a role of calcium or protein phosphorylation in sucrose signaling. In a detailed analysis, only okadaic acid altered sucrose transport activity. These results suggest a protein phosphatase is involved. We hypothesized that protein kinase inhibitors would have a neutral affect or increase symporter transcription. Transpirational feeding of the protein kinase inhibitor staurosporine had no impact on sucrose transport while calphostin C, an inhibitor of protein kinase C, caused a 60% increase. These data provided good evidence that protein phosphorylation plays a central role in regulating sucrose symporter expression and sucrose transport activity. To determine whether protein phosphorylation is involved in sucrose regulation of proton-sucrose symporter activity, we pre-fed leaves with staurosporine for 4 h and then fed the treated leaves water or 100 mM sucrose for an additional 20 h. Sucrose transport activity was higher than the water control in both staurosporine/water- and staurosporine/sucrose-fed leaves. In contrast, sucrose transport activity was only 40% of the water control in sucrose-fed leaves. Taken together, these results showed that a phosphorylation-dependent signal transduction pathway is involved in sucrose-mediated regulation of BvSUT1 gene expression, sucrose transport activity, and ultimately phloem loading. Publications originating from this work: Vaughn MW, GN. Harrington, and DR Bush 2002. Sucrose-mediated transcriptional regulation of sucrose symporter activity in the phloem. Proc. Natl. Acad. Sci. USA 99:10876-10880 Ransom-Hodgkins W, MW Vaughn, and DR Bush 2003. Protein phosphorylation mediates a key step in sucrose-regulation of the expression and transport activity of a beet proton-sucrose symporter. Planta 217:483-489 Harrington GN and Bush DR 2003. The bifunctional role of hexokinase in metabolism and glucose signaling. Plant Cell 15: 2493-2496« less

Respiratory Syncytial Virus Isolation by Combined Continuous Flow-Isopycnic Banding Centrifugation

PubMed Central

Cline, G. B.; Coates, Helen; Anderson, N. G.; Chanock, R. M.; Harris, W. W.

1967-01-01

A new zonal centrifuge rotor (B-IX) which combines continuous sample flow centrifugation with isopycnic banding has been used to isolate and concentrate respiratory syncytial virus from liter volumes of culture fluid. This isolation technique utilizes a sucrose density gradient to trap and isopycnically band the virus particles, and permits recovery of the particles from the rotor in an unaggregated condition. PMID:5621468

Purification of Giardia muris cysts by velocity sedimentation.

PubMed Central

Sauch, J F

1984-01-01

Giardia muris cysts were separated from fecal contaminants in primary isolates by unit gravity velocity sedimentation. Crude isolates obtained by centrifugation over 1.0 M sucrose were overlaid onto a Percoll density gradient, 1.01 to 1.03 g/ml. G. muris cysts were well separated from faster-sedimenting fecal debris and slower-sedimenting Spironucleus muris and bacteria in 1.5 h. PMID:6486790

Elimination of sucrose transport and hydrolysis in Saccharomyces cerevisiae: a platform strain for engineering sucrose metabolism

PubMed Central

Marques, Wesley Leoricy; Mans, Robert; Marella, Eko Roy; Cordeiro, Rosa Lorizolla; van den Broek, Marcel; Daran, Jean-Marc G.; Pronk, Jack T.; Gombert, Andreas K.; van Maris, Antonius J.A.

2017-01-01

Abstract Many relevant options to improve efficacy and kinetics of sucrose metabolism in Saccharomyces cerevisiae and, thereby, the economics of sucrose-based processes remain to be investigated. An essential first step is to identify all native sucrose-hydrolysing enzymes and sucrose transporters in this yeast, including those that can be activated by suppressor mutations in sucrose-negative strains. A strain in which all known sucrose-transporter genes (MAL11, MAL21, MAL31, MPH2, MPH3) were deleted did not grow on sucrose after 2 months of incubation. In contrast, a strain with deletions in genes encoding sucrose-hydrolysing enzymes (SUC2, MAL12, MAL22, MAL32) still grew on sucrose. Its specific growth rate increased from 0.08 to 0.25 h−1 after sequential batch cultivation. This increase was accompanied by a 3-fold increase of in vitro sucrose-hydrolysis and isomaltase activities, as well as by a 3- to 5-fold upregulation of the isomaltase-encoding genes IMA1 and IMA5. One-step Cas9-mediated deletion of all isomaltase-encoding genes (IMA1-5) completely abolished sucrose hydrolysis. Even after 2 months of incubation, the resulting strain did not grow on sucrose. This sucrose-negative strain can be used as a platform to test metabolic engineering strategies and for fundamental studies into sucrose hydrolysis or transport. PMID:28087672

Increased Photochemical Efficiency in Cyanobacteria via an Engineered Sucrose Sink.

PubMed

Abramson, Bradley W; Kachel, Benjamin; Kramer, David M; Ducat, Daniel C

2016-12-01

In plants, a limited capacity to utilize or export the end-products of the Calvin-Benson cycle (CB) from photosynthetically active source cells to non-photosynthetic sink cells can result in reduced carbon capture and photosynthetic electron transport (PET), and lowered photochemical efficiency. The down-regulation of photosynthesis caused by reduced capacity to utilize photosynthate has been termed 'sink limitation'. Recently, several cyanobacterial and algal strains engineered to overproduce target metabolites have exhibited increased photochemistry, suggesting that possible source-sink regulatory mechanisms may be involved. We directly examined photochemical properties following induction of a heterologous sucrose 'sink' in the unicellular cyanobacterium Synechococcus elongatus PCC 7942. We show that total photochemistry increases proportionally to the experimentally controlled rate of sucrose export. Importantly, the quantum yield of PSII (ΦII) increases in response to sucrose export while the PET chain becomes more oxidized from less PSI acceptor-side limitation, suggesting increased CB activity and a decrease in sink limitation. Enhanced photosynthetic activity and linear electron flow are detectable within hours of induction of the heterologous sink and are independent of pigmentation alterations or the ionic/osmotic effects of the induction system. These observations provide direct evidence that secretion of heterologous carbon bioproducts can be used as an alternative approach to improve photosynthetic efficiency, presumably by by-passing sink limitation. Our results also suggest that engineered microalgal production strains are valuable alternative models for examining photosynthetic sink limitation because they enable greater control and monitoring of metabolite fluxes relative to plants. © The Author 2016. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Equivalences between refractive index and equilibrium water content of conventional and silicone hydrogel soft contact lenses from automated and manual refractometry.

PubMed

González-Méijome, José M; López-Alemany, Antonio; Lira, Madalena; Almeida, José B; Oliveira, M Elisabete C D Real; Parafita, Manuel A

2007-01-01

The purpose of the present study was to develop mathematical relationships that allow obtaining equilibrium water content and refractive index of conventional and silicone hydrogel soft contact lenses from refractive index measures obtained with automated refractometry or equilibrium water content measures derived from manual refractometry, respectively. Twelve HEMA-based hydrogels of different hydration and four siloxane-based polymers were assayed. A manual refractometer and a digital refractometer were used. Polynomial models obtained from the sucrose curves of equilibrium water content against refractive index and vice-versa were used either considering the whole range of sucrose concentrations (16-100% equilibrium water content) or a range confined to the equilibrium water content of current soft contact lenses (approximately 20-80% equilibrium water content). Values of equilibrium water content measured with the Atago N-2E and those derived from the refractive index measurement with CLR 12-70 by the applications of sucrose-based models displayed a strong linear correlation (r2 = 0.978). The same correlations were obtained when the models are applied to obtain refractive index values from the Atago N-2E and compared with those (values) given by the CLR 12-70 (r2 = 0.978). No significantly different results are obtained between models derived from the whole range of the sucrose solution or the model limited to the normal range of soft contact lens hydration. Present results will have implications for future experimental and clinical research regarding normal hydration and dehydration experiments with hydrogel polymers, and particularly in the field of contact lenses. 2006 Wiley Periodicals, Inc.

4,6-α-glucanotransferase, a novel enzyme that structurally and functionally provides an evolutionary link between glycoside hydrolase enzyme families 13 and 70.

PubMed

Kralj, Slavko; Grijpstra, Pieter; van Leeuwen, Sander S; Leemhuis, Hans; Dobruchowska, Justyna M; van der Kaaij, Rachel M; Malik, Amarila; Oetari, Ariyanti; Kamerling, Johannis P; Dijkhuizen, Lubbert

2011-11-01

Lactobacillus reuteri 121 uses the glucosyltransferase A (GTFA) enzyme to convert sucrose into large amounts of the α-D-glucan reuteran, an exopolysaccharide. Upstream of gtfA lies another putative glucansucrase gene, designated gtfB. Previously, we have shown that the purified recombinant GTFB protein/enzyme is inactive with sucrose. Various homologs of gtfB are present in other Lactobacillus strains, including the L. reuteri type strain, DSM 20016, the genome sequence of which is available. Here we report that GTFB is a novel α-glucanotransferase enzyme with disproportionating (cleaving α1→4 and synthesizing α1→6 and α1→4 glycosidic linkages) and α1→6 polymerizing types of activity on maltotetraose and larger maltooligosaccharide substrates (in short, it is a 4,6-α-glucanotransferase). Characterization of the types of compounds synthesized from maltoheptaose by matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS), methylation analysis, and 1-dimensional ¹H nuclear magnetic resonance (NMR) spectroscopy revealed that only linear products were made and that with increasing degrees of polymerization (DP), more α1→6 glycosidic linkages were introduced into the final products, ranging from 18% in the incubation mixture to 33% in an enriched fraction. In view of its primary structure, GTFB clearly is a member of the glycoside hydrolase 70 (GH70) family, comprising enzymes with a permuted (β/α)₈ barrel that use sucrose to synthesize α-D-glucan polymers. The GTFB enzyme reaction and product specificities, however, are novel for the GH70 family, resembling those of the GH13 α-amylase type of enzymes in using maltooligosaccharides as substrates but differing in introducing a series of α1→6 glycosidic linkages into linear oligosaccharide products. We conclude that GTFB represents a novel evolutionary intermediate between the GH13 and GH70 enzyme families, and we speculate about its origin.

Growth and Survival of Some Probiotic Strains in Simulated Ice Cream Conditions

NASA Astrophysics Data System (ADS)

Homayouni, A.; Ehsani, M. R.; Azizi, A.; Razavi, S. H.; Yarmand, M. S.

A Completely Randomized Design (CRD) experiment was applied in triplicates to evaluate the survival of four probiotic strains in simulated ice cream conditions. The growth and survival rate of these probiotic strains (Lactobacillus acidophilus, Lactobacillus casei, Bifidobacterium bifidum and Bifidobacterium longum) in varying amount of sucrose (10, 15, 20 and 25%), oxygen scavenging components (0.05% L-cysteine and 0.05% L-ascorbate) and temperatures (4 and -20°C) during different periods of time (1, 2 and 3 months) were evaluated in MRS-broth medium. Optical density at 580 nm was used to measure growth. Lactobacilli strains proved to be highly resistant in comparison with Biffidobacteria strains. The viable cell number of Lactobacillus casei in different sucrose concentrations, different oxidoreduction potentials and refrigeration temperature was 1x1010, 2x108 and 5x107 cfu mL-1, respectively. Growth and survival rate of Lactobacillus casei showed to be the highest.

Isolation and purification of a granulosis virus from infected larvae of the Indian meal moth, Plodia interpunctella.

PubMed

Tweeten, K A; Bulla, L A; Consigli, R A

1977-09-01

A procedure was developed for purification of a granulosis virus inclusion body produced in vivo in the Indian meal moth, Plodia interpunctella (Hübner). Purification was accomplished by differential centrifugation, treatment with sodium deoxycholate, and velocity sedimentation in sucrose gradients. The adequacy of the procedure was confirmed by mixing experiments in which uninfected, radioactively labeled larvae were mixed with infected, unlabeled larvae. After purification, the virus was shown to be free of host tissue, to retain its physical integrity, and to be highly infectious per os. Preparations of purified virus consisted of homogeneous populations of intact inclusion bodies (210 by 380 nm) whose buoyant density was 1.271 g/cm3 when centrifuged to equilibrium in sucrose gradients. Electron microscopy of thin-sectioned virus or of virus sequentially disrupted on electron microscope grids demonstrated three components: protein matrix, envelope, and nucleocapsid.

Isolation and purification of a granulosis virus from infected larvae of the Indian meal moth, Plodia interpunctella.

PubMed Central

Tweeten, K A; Bulla, L A; Consigli, R A

1977-01-01

A procedure was developed for purification of a granulosis virus inclusion body produced in vivo in the Indian meal moth, Plodia interpunctella (Hübner). Purification was accomplished by differential centrifugation, treatment with sodium deoxycholate, and velocity sedimentation in sucrose gradients. The adequacy of the procedure was confirmed by mixing experiments in which uninfected, radioactively labeled larvae were mixed with infected, unlabeled larvae. After purification, the virus was shown to be free of host tissue, to retain its physical integrity, and to be highly infectious per os. Preparations of purified virus consisted of homogeneous populations of intact inclusion bodies (210 by 380 nm) whose buoyant density was 1.271 g/cm3 when centrifuged to equilibrium in sucrose gradients. Electron microscopy of thin-sectioned virus or of virus sequentially disrupted on electron microscope grids demonstrated three components: protein matrix, envelope, and nucleocapsid. Images PMID:334076

Proliferation and glucosinolates accumulation of broccoli adventitious roots in liquid medium

NASA Astrophysics Data System (ADS)

Nhut, Nguyen Minh; Tien, Le Thi Thuy

2017-09-01

Cotyledons from 7-day-old in vitro broccoli seedling were used as explant source in adventitious root induction on MS medium supplemented with 30 g/l sucrose, 1.6 mg/l IBA and 7 g/l agar. Adventitious roots from cotyledons were transferred to liquid medium containing the same components as rooting medium for two weeks, then subcultured to MS medium with diferent sugar, macrominerals and casein hydrolysate concentrations. The best adventitious root growth was observed in half-strength MS medium supplemented with 40 g/l sucrose, 600 mg/l casein hydrolysate and 1.6 mg/l IBA (growth index of 4.00 in about 14 culture days with inoculum density of 1.0 g fresh weight / 30 ml of culture medium). The culturing process can be stopped on the 28th day for root biomass and on the 35th day for glucosinolates.

A polygalacturonase localized in the Golgi apparatus in Pisum sativum.

PubMed

Ohashi, Takao; Jinno, Jun; Inoue, Yoshiyuki; Ito, Shoko; Fujiyama, Kazuhito; Ishimizu, Takeshi

2017-09-01

Pectin is a plant cell wall constituent that is mainly composed of polygalacturonic acid (PGA), a linear α1,4-d-galacturonic acid (GalUA) backbone. Polygalacturonase (PG) hydrolyzes the α1,4-linkages in PGA. Nearly all plant PGs identified thus far are secreted as soluble proteins. Here we describe the microsomal PG activity in pea (Pisum sativum) epicotyls and present biochemical evidence that it was localized to the Golgi apparatus, where pectins are biosynthesized. The microsomal PG was purified, and it was enzymatically characterized. The purified enzyme showed maximum activity towards pyridylaminated oligogalacturonic acids with six degrees of polymerization (PA-GalUA6), with a Km value of 11 μM for PA-GalUA6. The substrate preference of the enzyme was complementary to that of PGA synthase. The main PG activity in microsomes was detected in the Golgi fraction by sucrose density gradient ultracentrifugation. The activity of the microsomal PG was lower in rapidly growing epicotyls, in contrast to the high expression of PGA synthase. The role of this PG in the regulation of pectin biosynthesis or plant growth is discussed. © The Authors 2017. Published by Oxford University Press on behalf of the Japanese Biochemical Society. All rights reserved.

Incubation of sucrose craving: effects of reduced training and sucrose pre-loading

PubMed Central

Grimm, Jeffrey W.; Fyall, Amber M.; Osincup, Dan P.

2010-01-01

Time-dependent increases in cue-induced reward seeking after forced abstinence were described in rats with a history of cocaine or sucrose self-administration, suggesting reward craving incubates over time. In the present study, we examined the effects of reduced training experience, or sucrose pre-loading just prior to testing, on the incubation of sucrose craving. Sucrose seeking (responding in extinction and then for a sucrose-paired cue) increased over time in groups of rats that self-administered sucrose 6 h/day for 10 days and were tested at 1, 7, or 30 days of forced abstinence. We found that groups of rats that had self-administered 2 instead of 6 h/day showed a similar profile of responding. Incubation of sucrose craving was attenuated by free access to sucrose in home cages for 17 h immediately prior to testing assessed as extinction responding on days 1 and 30. However, this sucrose pre-loading had no effect on the time-dependent increase in responding for the sucrose-paired cue. In summary, reducing the training experience had no effect on the incubation of sucrose craving and free access to sucrose had only a limited effect–attenuating extinction responding. These results illustrate the strength of the incubation of craving and further suggest long-term changes in brain motivational circuitry following sucrose self-administration. PMID:15642609

Copper-induced alteration in sucrose partitioning and its relationship to the root growth of two Elsholtzia haichowensis Sun populations.

PubMed

Li, Min-Jing; Xiong, Zhi-Ting; Liu, Hui; Kuo, Yi-Ming; Tong, Lei

2016-10-02

Hydroponic culture was used to comparatively investigate the copper (Cu)-induced alteration to sucrose metabolism and biomass allocation in two Elsholtzia haichowensis Sun populations with one from a Cu-contaminated site (CS) and the other from a non-contaminated site (NCS). Experimental results revealed that biomass allocation preferred roots over shoots in CS population, and shoots over roots in NCS population under Cu exposure. The difference in biomass allocation was correlated with the difference in sucrose partitioning between the two populations. Cu treatment (45 μM) significantly decreased leaf sucrose content and increased root sucrose content in CS population as a result of the increased activities of leaf sucrose synthesis enzymes (sucrose phosphate synthetase and sucrose synthase) and root sucrose cleavage enzyme (vacuolar invertase), which led to increased sucrose transport from leaves to roots. In contrast, higher Cu treatment increased sucrose content in leaves and decreased sucrose content in roots in NCS population as a result of the decreased activities of root sucrose cleavage enzymes (vacuolar and cell wall invertases) that led to less sucrose transport from leaves to roots. These results provide important insights into carbon resource partitioning and biomass allocation strategies in metallophytes and are beneficial for the implementation of phytoremediation techniques.

Reinforcement value and substitutability of sucrose and wheel running: implications for activity anorexia.

PubMed

Belke, Terry W; Pierce, W David; Duncan, Ian D

2006-09-01

Choice between sucrose and wheel-running reinforcement was assessed in two experiments. In the first experiment, ten male Wistar rats were exposed to concurrent VI 30 s VI 30 s schedules of wheel-running and sucrose reinforcement. Sucrose concentration varied across concentrations of 2.5, 7.5, and 12.5%. As concentration increased, more behavior was allocated to sucrose and more reinforcements were obtained from that alternative. Allocation of behavior to wheel running decreased, but obtained wheel-running reinforcement did not change. Overall, the results suggested that food-deprived rats were sensitive to qualitative changes in food supply (sucrose concentration) while continuing to defend a level of physical activity (wheel running). In the second study, 15 female Long Evans rats were exposed to concurrent variable ratio schedules of sucrose and wheel-running, wheel-running and wheel-running, and sucrose and sucrose reinforcement. For each pair of reinforcers, substitutability was assessed by the effect of income-compensated price changes on consumption of the two reinforcers. Results showed that, as expected, sucrose substituted for sucrose and wheel running substituted for wheel running. Wheel running, however, did not substitute for sucrose; but sucrose partially substituted for wheel running. We address the implications of the interrelationships of sucrose and wheel running for an understanding of activity anorexia.

Reinforcement Value and Substitutability of Sucrose and Wheel Running: Implications for Activity Anorexia

PubMed Central

Belke, Terry W; Duncan, Ian D; David Pierce, W

2006-01-01

Choice between sucrose and wheel-running reinforcement was assessed in two experiments. In the first experiment, ten male Wistar rats were exposed to concurrent VI 30 s VI 30 s schedules of wheel-running and sucrose reinforcement. Sucrose concentration varied across concentrations of 2.5, 7.5, and 12.5%. As concentration increased, more behavior was allocated to sucrose and more reinforcements were obtained from that alternative. Allocation of behavior to wheel running decreased, but obtained wheel-running reinforcement did not change. Overall, the results suggested that food-deprived rats were sensitive to qualitative changes in food supply (sucrose concentration) while continuing to defend a level of physical activity (wheel running). In the second study, 15 female Long Evans rats were exposed to concurrent variable ratio schedules of sucrose and wheel-running, wheel-running and wheel-running, and sucrose and sucrose reinforcement. For each pair of reinforcers, substitutability was assessed by the effect of income-compensated price changes on consumption of the two reinforcers. Results showed that, as expected, sucrose substituted for sucrose and wheel running substituted for wheel running. Wheel running, however, did not substitute for sucrose; but sucrose partially substituted for wheel running. We address the implications of the interrelationships of sucrose and wheel running for an understanding of activity anorexia. PMID:17002224

Characterization of Sugar Contents and Sucrose Metabolizing Enzymes in Developing Leaves of Hevea brasiliensis

PubMed Central

Zhu, Jinheng; Qi, Jiyan; Fang, Yongjun; Xiao, Xiaohu; Li, Jiuhui; Lan, Jixian; Tang, Chaorong

2018-01-01

Sucrose-metabolizing enzymes in plant leaves have hitherto been investigated mainly in temperate plants, and rarely conducted in tandem with gene expression and sugar analysis. Here, we investigated the sugar content, gene expression, and the activity of sucrose-metabolizing enzymes in the leaves of Hevea brasiliensis, a tropical tree widely cultivated for natural rubber. Sucrose, fructose and glucose were the major sugars detected in Hevea leaves at four developmental stages (I to IV), with starch and quebrachitol as minor saccharides. Fructose and glucose contents increased until stage III, but decreased strongly at stage IV (mature leaves). On the other hand, sucrose increased continuously throughout leaf development. Activities of all sucrose-cleaving enzymes decreased markedly at maturation, consistent with transcript decline for most of their encoding genes. Activity of sucrose phosphate synthase (SPS) was low in spite of its high transcript levels at maturation. Hence, the high sucrose content in mature leaves was not due to increased sucrose-synthesizing activity, but more to the decline in sucrose cleavage. Gene expression and activities of sucrose-metabolizing enzymes in Hevea leaves showed striking differences compared with other plants. Unlike in most other species where vacuolar invertase predominates in sucrose cleavage in developing leaves, cytoplasmic invertase and sucrose synthase (cleavage direction) also featured prominently in Hevea. Whereas SPS is normally responsible for sucrose synthesis in plant leaves, sucrose synthase (synthesis direction) was comparable or higher than that of SPS in Hevea leaves. Mature Hevea leaves had an unusually high sucrose:starch ratio of about 11, the highest reported to date in plants. PMID:29449852

Sucrose and Related Oligosaccharides

NASA Astrophysics Data System (ADS)

Eggleston, Gillian

Sucrose (α-D-glucopyranosyl-(1↔2)-β-D-fructofuranoside) is the most common low-molecular-weight sugar found in the plant kingdom. It is ubiquitously known as common table sugar and primarily produced industrially from sugarcane (Saccharum officinarum) and sugar beet (Beta vulgaris); the basics of the industrial manufacture of sucrose are outlined in this chapter. Commercial sucrose has a very high purity (> 99.9%) making it one of the purest organic substances produced on an industrial scale. Value-addition to sucrose via chemical and biotechnological reactions is becoming more important for the diversification of the sugar industry to maintain the industries' competitiveness in a world increasingly turning to a bio-based economy. The basis for the chemical reactivity of sucrose is the eight hydroxyl groups present on the molecule, although, sucrose chemical reactivity is regarded as difficult. Increasing use of enzymatic biotechnological techniques to derivatize sucrose is expected, to add special functionalities to sucrose products like biodegradability, biocompatibility, and non-toxicity. Analysis of sucrose by colorimetric, enzymatic, oxidation-reduction and chromatography methods are discussed. Oligosaccharides related to sucrose are outlined in detail and include sucrose-based plant, honey and in vitro oligosaccharides.

GP3 is a structural component of the PRRSV type II (US) virion

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lima, M. de; Departamento de Microbiologia e Parasitologia, Universidade Federal Fluminense, Niteroi, RJ; Ansari, I.H.

2009-07-20

Glycoprotein 3 (GP3) is a highly glycosylated PRRSV envelope protein which has been reported as being present in the virions of PRRSV type I, while missing in the type II PRRSV (US) virions. We herein present evidence that GP3 is indeed incorporated in the virus particles of a North American strain of PRRSV (FL12), at a density that is consistent with the minor structural role assigned to GP3 in members of the Arterivirus genus. Two 15aa peptides corresponding to two different immunodominant linear epitopes of GP3 derived from the North American strain of PRRSV (FL12) were used as antigen tomore » generate a rabbit monospecific antiserum to this protein. The specificity of this anti-GP3 antiserum was confirmed by radioimmunoprecipitation (RIP) assay using BHK-21 cells transfected with GP3 expressing plasmid, MARC-145 cells infected with FL12 PRRSV, as well as by confocal microscopy on PRRSV-infected MARC-145 cells. To test if GP3 is a structural component of the virion, {sup 35}S-labelled PRRSV virions were pelleted through a 30% sucrose cushion, followed by a second round of purification on a sucrose gradient (20-60%). Virions were detected in specific gradient fractions by radioactive counts and further confirmed by viral infectivity assay in MARC 145 cells. The GP3 was detected in gradient fractions containing purified virions by RIP using anti-GP3 antiserum. Predictably, the GP3 was less abundant in purified virions than other major structural envelope proteins such as GP5 and M. Further evidence of the presence of GP3 at the level of PRRSV FL12 envelope was obtained by immunogold staining of purified virions from the supernatant of infected cells with anti-GP3 antiserum. Taken together, these results indicate that GP3 is a minor structural component of the PRRSV type II (FL12 strain) virion, as had been previously described for PRRSV type I.« less

Hierarchical porous carbon materials prepared using nano-ZnO as a template and activation agent for ultrahigh power supercapacitors.

PubMed

Wang, Haoran; Yu, Shukai; Xu, Bin

2016-09-20

Hierarchical porous carbon materials with high surface areas and a localized graphitic structure were simply prepared from sucrose using nano-ZnO as a hard template, activation agent and graphitization catalyst simultaneously, which exhibit an outstanding high-rate performance and can endure an ultrafast scan rate of 20 V s -1 and ultrahigh current density of 1000 A g -1 .

Lipase activities in castor bean endosperm during germinaion. [Ricinus communis; glyoxysomes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Muto, S.; Beevers, H.

1974-01-01

Two lipases were found in extracts from castor bean (Ricinus communis L.) endosperm. One, with optimal activity at pH 5.0 (acid lipase), was present in dry seeds and displayed high activity during the first 2 days of germination. The second, with an alkaline pH optimum (alkaline lipase), was particularly active during days 3 to 5. When total homogenates of endosperm were fractionated into fat layer, supernatant, and particulate fractions, the acid lipase was recovered in the fat layer, and the alkaline lipase was located primarily in the particulate fraction. Sucrose density gradient centrifugation showed that the alkaline lipase was locatedmore » mainly in glyoxysomes, with some 30 percent of the activity in the endoplasmic reticulum. When glyoxysomes were broken by osmotic shock and exposed to KCl, which solubilizes most of the enzymes, the alkaline lipase remained particulate and was recovered with the glyoxysomal ''ghosts'' at equilibrium density 1.21 g/cm/sup 3/ on the sucrose gradient. Association of the lipase with the glyoxysomal membrane was supported by the responses to detergents and to butanol. The alkaline lipase hydrolyzed only monosubstituted glycerols. The roles of the two lipases in lipid utilization during germination of castor bean are discussed.« less

Oxygen exposure promotes fuel diversity for Shewanella oneidensis microbial fuel cells.

PubMed

Biffinger, Justin C; Byrd, Jacqueline N; Dudley, Breanna L; Ringeisen, Bradley R

2008-01-18

Miniature microbial fuel cells (mini-MFCs) were used to monitor the current generated by Shewanella oneidensis DSP10 under both anaerobic and aerobic conditions when exposed to glucose as a potential electron donor. In addition to glucose, other carbon fuels including fructose, sucrose, acetate, and ascorbic acid were also tested. When the anolyte containing S. oneidensis was grown in the presence of oxygen, power densities of 270+/-10, 350+/-20, and 120+/-10 W/m(3) were recorded from the mini-MFC for glucose, fructose, and ascorbic acid electron donors, respectively, while sucrose and acetate produced no response. The power produced from glucose decreased considerably (

Reverse Transcriptase-Containing Particles Induced in Rous Sarcoma Virus-Transformed Rat Cells by Arginine Deprivation

PubMed Central

Kotler, Moshe; Weinberg, Eynat; Haspel, Osnat; Becker, Yechiel

1972-01-01

Incubation of rat cells transformed by Rous sarcoma virus (RSV) in an arginine-deficient medium resulted in accumulation of particles in the culture medium. Such particles did not appear when the transformed rat cells were incubated in a complete medium nor in the medium of primary rat cells which were incubated either in arginine-deficient or complete media. The particles which were released from the arginine-deprived transformed rat cells resemble C-type particles in their properties. These particles band in sucrose gradients at a density of 1.16 g/ml and contain 35S ribonucleic acid (RNA) molecules and a reverse transcriptase activity. Analysis of the cytoplasm of transformed and primary rat cells, deprived and undeprived of arginine, revealed the presence of reverse transcriptase-containing particles which banded in sucrose gradients at a density of 1.14 g/ml. These particles differed from the particles released into the medium by the arginine-deprived RSV-transformed rat cells. The deoxyribonucleic acid (DNA) molecules synthesized in vitro by the reverse transcriptase present in the particles isolated from the medium of arginine-deprived cells hybridized to RSV RNA, whereas the DNA synthesized by the cell-bound enzyme had no homology to RSV RNA. PMID:4116137

Modeling the Effects of Light and Sucrose on In Vitro Propagated Plants: A Multiscale System Analysis Using Artificial Intelligence Technology

PubMed Central

Gago, Jorge; Martínez-Núñez, Lourdes; Landín, Mariana; Flexas, Jaume; Gallego, Pedro P.

2014-01-01

Background Plant acclimation is a highly complex process, which cannot be fully understood by analysis at any one specific level (i.e. subcellular, cellular or whole plant scale). Various soft-computing techniques, such as neural networks or fuzzy logic, were designed to analyze complex multivariate data sets and might be used to model large such multiscale data sets in plant biology. Methodology and Principal Findings In this study we assessed the effectiveness of applying neuro-fuzzy logic to modeling the effects of light intensities and sucrose content/concentration in the in vitro culture of kiwifruit on plant acclimation, by modeling multivariate data from 14 parameters at different biological scales of organization. The model provides insights through application of 14 sets of straightforward rules and indicates that plants with lower stomatal aperture areas and higher photoinhibition and photoprotective status score best for acclimation. The model suggests the best condition for obtaining higher quality acclimatized plantlets is the combination of 2.3% sucrose and photonflux of 122–130 µmol m−2 s−1. Conclusions Our results demonstrate that artificial intelligence models are not only successful in identifying complex non-linear interactions among variables, by integrating large-scale data sets from different levels of biological organization in a holistic plant systems-biology approach, but can also be used successfully for inferring new results without further experimental work. PMID:24465829

Modeling the effects of light and sucrose on in vitro propagated plants: a multiscale system analysis using artificial intelligence technology.

PubMed

Gago, Jorge; Martínez-Núñez, Lourdes; Landín, Mariana; Flexas, Jaume; Gallego, Pedro P

2014-01-01

Plant acclimation is a highly complex process, which cannot be fully understood by analysis at any one specific level (i.e. subcellular, cellular or whole plant scale). Various soft-computing techniques, such as neural networks or fuzzy logic, were designed to analyze complex multivariate data sets and might be used to model large such multiscale data sets in plant biology. In this study we assessed the effectiveness of applying neuro-fuzzy logic to modeling the effects of light intensities and sucrose content/concentration in the in vitro culture of kiwifruit on plant acclimation, by modeling multivariate data from 14 parameters at different biological scales of organization. The model provides insights through application of 14 sets of straightforward rules and indicates that plants with lower stomatal aperture areas and higher photoinhibition and photoprotective status score best for acclimation. The model suggests the best condition for obtaining higher quality acclimatized plantlets is the combination of 2.3% sucrose and photonflux of 122-130 µmol m(-2) s(-1). Our results demonstrate that artificial intelligence models are not only successful in identifying complex non-linear interactions among variables, by integrating large-scale data sets from different levels of biological organization in a holistic plant systems-biology approach, but can also be used successfully for inferring new results without further experimental work.

A transferable sucrose utilization approach for non-sucrose-utilizing Escherichia coli strains.

PubMed

Bruschi, Michele; Boyes, Simon J; Sugiarto, Haryadi; Nielsen, Lars K; Vickers, Claudia E

2012-01-01

Sucrose has economic and environmental advantages over glucose as a feedstock for bioprocesses. E. coli is widely used in industry, but the majority of current industrial E. coli strains cannot utilize sucrose. Previous attempts to transfer sucrose catabolic capabilities into non-sucrose-utilizing strains have met with limited success due to low growth rates on sucrose and phenotypic instability of the engineered strains. To address these problems, we developed a transferrable sucrose utilization cassette which confers efficient sucrose catabolism when integrated onto the E. coli chromosome. The cassette was based on the csc genes from E. coli W, a strain which grows very quickly on sucrose. Both plasmid-borne expression and chromosomal integration of a repressor-less sucrose utilizing cassette were investigated in E. coli strains K-12, B and C. In contrast to previous studies, strains harboring chromosomal cassettes could grow at the same rate as they do on glucose. Interestingly, we also discovered that spontaneous chromosomal integration of the csc genes was required to allow efficient growth from plasmid-transformed strains. The ability to engineer industrial strains for efficient sucrose utilization will allow substitution of sucrose for glucose in industrial fermentations. This will encourage the use of sucrose as a carbon source and assist in transition of our petrochemical-based economy to a bio-based economy. Crown Copyright © 2011. Published by Elsevier Inc. All rights reserved.

Time-dependent decreases in nucleus accumbens AMPA/NMDA ratio and incubation of sucrose craving in adolescent and adult rats.

PubMed

Counotte, Danielle S; Schiefer, Christopher; Shaham, Yavin; O'Donnell, Patricio

2014-04-01

There is evidence that cue-induced sucrose seeking progressively increases after cessation of oral sucrose self-administration (incubation of sucrose craving) in both adolescent and adult rats. The synaptic plasticity changes associated with this incubation at different age groups are unknown. We assessed whether incubation of sucrose craving in rats trained to self-administer sucrose as young adolescents, adolescents, or adults is associated with changes in 2-amino-3-(3-hydroxy-5-methyl-isoxazol-4-yl)propanoic acid (AMPA)/N-methyl-D-aspartate (NMDA) ratio (a measure of postsynaptic changes in synaptic strength) in nucleus accumbens. Three age groups initiated oral sucrose self-administration training (10 days) on postnatal day (P) 35 (young adolescents), P42 (adolescents), or P70 (adults). They were then tested for cue-induced sucrose seeking (assessed in an extinction test) on abstinence days 1 and 21. Separate groups of rats were trained to self-administer sucrose or water (a control condition), and assessed for AMPA/NMDA ratio in nucleus accumbens on abstinence days 1-3 and 21. Adult rats earned more sucrose rewards, but sucrose intake per body weight was higher in young adolescent rats. Time-dependent increases in cue-induced sucrose seeking (incubation of sucrose craving) were more pronounced in adult rats, less pronounced in adolescents, and not detected in young adolescents. On abstinence day 21, but not days 1-3, AMPA/NMDA ratio in nucleus accumbens were decreased in rats that self-administered sucrose as adults and adolescents, but not young adolescents. Our data demonstrate age-dependent changes in magnitude of incubation of sucrose craving and nucleus accumbens synaptic plasticity after cessation of sucrose self-administration.

Isolation of zymogen granules from rat pancreas.

PubMed

Rindler, Michael J

2006-01-01

This unit describes methods for preparing zymogen granules from rat pancreas. Zymogen granules are storage organelles in pancreatic acinar cells containing digestive enzymes that are released into the pancreatic duct. The protocols in this unit take advantage of the large size (up to 1 microm diameter) and high density (>1.20 g/cm(3) on sucrose gradients) of the granules as compared to other cellular organelles. They use a combination of differential sedimentation and density gradient separation to accomplish the purification. Similar procedures can be used to isolate zymogen granules from mouse pancreas and canine pancreas. A protocol for preparing zymogen granules from dog pancreas is also included.

Method for providing a low density high strength polyurethane foam

DOEpatents

Whinnery, Jr., Leroy L.; Goods, Steven H.; Skala, Dawn M.; Henderson, Craig C.; Keifer, Patrick N.

2013-06-18

Disclosed is a method for making a polyurethane closed-cell foam material exhibiting a bulk density below 4 lbs/ft.sup.3 and high strength. The present embodiment uses the reaction product of a modified MDI and a sucrose/glycerine based polyether polyol resin wherein a small measured quantity of the polyol resin is "pre-reacted" with a larger quantity of the isocyanate in a defined ratio such that when the necessary remaining quantity of the polyol resin is added to the "pre-reacted" resin together with a tertiary amine catalyst and water as a blowing agent, the polymerization proceeds slowly enough to provide a stable foam body.

Simplified large African carnivore density estimators from track indices.

PubMed

Winterbach, Christiaan W; Ferreira, Sam M; Funston, Paul J; Somers, Michael J

2016-01-01

The range, population size and trend of large carnivores are important parameters to assess their status globally and to plan conservation strategies. One can use linear models to assess population size and trends of large carnivores from track-based surveys on suitable substrates. The conventional approach of a linear model with intercept may not intercept at zero, but may fit the data better than linear model through the origin. We assess whether a linear regression through the origin is more appropriate than a linear regression with intercept to model large African carnivore densities and track indices. We did simple linear regression with intercept analysis and simple linear regression through the origin and used the confidence interval for ß in the linear model y  =  αx  + ß, Standard Error of Estimate, Mean Squares Residual and Akaike Information Criteria to evaluate the models. The Lion on Clay and Low Density on Sand models with intercept were not significant ( P  > 0.05). The other four models with intercept and the six models thorough origin were all significant ( P  < 0.05). The models using linear regression with intercept all included zero in the confidence interval for ß and the null hypothesis that ß = 0 could not be rejected. All models showed that the linear model through the origin provided a better fit than the linear model with intercept, as indicated by the Standard Error of Estimate and Mean Square Residuals. Akaike Information Criteria showed that linear models through the origin were better and that none of the linear models with intercept had substantial support. Our results showed that linear regression through the origin is justified over the more typical linear regression with intercept for all models we tested. A general model can be used to estimate large carnivore densities from track densities across species and study areas. The formula observed track density = 3.26 × carnivore density can be used to estimate densities of large African carnivores using track counts on sandy substrates in areas where carnivore densities are 0.27 carnivores/100 km 2 or higher. To improve the current models, we need independent data to validate the models and data to test for non-linear relationship between track indices and true density at low densities.

High sucrose consumption induces memory impairment in rats associated with electrophysiological modifications but not with metabolic changes in the hippocampus.

PubMed

Lemos, C; Rial, D; Gonçalves, F Q; Pires, J; Silva, H B; Matheus, F C; da Silva, A C; Marques, J M; Rodrigues, R J; Jarak, I; Prediger, R D; Reis, F; Carvalho, R A; Pereira, F C; Cunha, R A

2016-02-19

High sugar consumption is a risk factor for metabolic disturbances leading to memory impairment. Thus, rats subject to high sucrose intake (HSu) develop a metabolic syndrome and display memory deficits. We now investigated if these HSu-induced memory deficits were associated with metabolic and electrophysiological alterations in the hippocampus. Male Wistar rats were submitted for 9 weeks to a sucrose-rich diet (35% sucrose solution) and subsequently to a battery of behavioral tests; after sacrifice, their hippocampi were collected for ex vivo high-resolution magic angle spinning (HRMAS) metabolic characterization and electrophysiological extracellular recordings in slices. HSu rats displayed a decreased memory performance (object displacement and novel object recognition tasks) and helpless behavior (forced swimming test), without altered locomotion (open field). HRMAS analysis indicated a similar hippocampal metabolic profile of HSu and control rats. HSu rats also displayed no change of synaptic transmission and plasticity (long-term potentiation) in hippocampal Schaffer fibers-CA1 pyramid synapses, but had decreased amplitude of long-term depression in the temporoammonic (TA) pathway. Furthermore, HSu rats had an increased density of inhibitory adenosine A1 receptors (A1R), that translated into a greater potency of A1R in Schaffer fiber synapses, but not in the TA pathway, whereas the endogenous activation of A1R in HSu rats was preserved in the TA pathway but abolished in Schaffer fiber synapses. These results suggest that HSu triggers a hippocampal-dependent memory impairment that is not associated with altered hippocampal metabolism but is probably related to modified synaptic plasticity in hippocampal TA synapses. Copyright © 2015 IBRO. Published by Elsevier Ltd. All rights reserved.

The influence of temperature, sucrose and lactose on dilute solution properties of basil (Ocimumbasilicum) seed gum.

PubMed

Mirabolhassani, Seyed Elias; Rafe, Ali; Razavi, Seyed M A

2016-12-01

Hydrocolloid interactions with solvent/cosolutes play a vital role in the resolution of their functional properties. Basil seed gum (BSG) is a plant-derived hydrocolloid which has been found many applications in food formulations as stabilizer, emulsifier, thickener and gelling agents. Sucrose and lactose are the most effective sugars in textural and sensorial properties of bakery and dairy products which adding them to solutions containing hydrocolloids can be helpful to approach a proper formula. In this paper, the effect of temperature (25-65°C), sucrose (10, 20, 30 and 40%) and lactose (5, 10 and 15%) were investigated through some molecular parameters of BSG. Results revealed high flexible chain (665.35), intrinsic viscosity (11.38 dl/g) and hydrogel content (73%) of BSG, which may be attributed to some extent by its high molecular weight (1.73×10 6 Da). The density and intrinsic viscosity of BSG were diminished by growing temperature from 25 to 55°C. Among five models, which were applied to estimate intrinsic viscosity, Higiro-2 was the most suitable model at varying temperatures and cosolutes concentrations. The sugars showed a significant effect on the molecular parameters of BSG such as swollen specific volume, shape function, hydration parameter, and coil dimensions. The sugars showed more impact on the [η] of BSG and its molecular parameters than that of temperature. However, lactose had a more prominent effect on the BSG dimensions than that of sucrose, which can be related to its molecular conformation and spatial orientation. It is feasible to make a proper formula by BSG and explain some phenomena in its applications in food and pharmaceutical systems. Copyright © 2016 Elsevier B.V. All rights reserved.

Differential neural representation of oral ethanol by central taste-sensitive neurons in ethanol-preferring and genetically heterogeneous rats

PubMed Central

Wilson, David M.; Brasser, Susan M.

2011-01-01

In randomly bred rats, orally applied ethanol stimulates neural substrates for appetitive sweet taste. To study associations between ethanol's oral sensory characteristics and genetically mediated ethanol preference, we made electrophysiological recordings of oral responses (spike density) by taste-sensitive nucleus tractus solitarii neurons in anesthetized selectively bred ethanol-preferring (P) rats and their genetically heterogeneous Wistar (W) control strain. Stimuli (25 total) included ethanol [3%, 5%, 10%, 15%, 25%, and 40% (vol/vol)], a sucrose series (0.01, 0.03, 0.1, 0.3, 0.5, and 1 M), and other sweet, salt, acidic, and bitter stimuli; 50 P and 39 W neurons were sampled. k-means clustering applied to the sucrose response series identified cells showing high (S1) or relatively low (S0) sensitivity to sucrose. A three-way factorial analysis revealed that activity to ethanol was influenced by a neuron's sensitivity to sucrose, ethanol concentration, and rat line (P = 0.01). Ethanol produced concentration-dependent responses in S1 neurons that were larger than those in S0 cells. Although responses to ethanol by S1 cells did not differ between lines, neuronal firing rates to ethanol in S0 cells increased across concentration only in P rats. Correlation and multivariate analyses revealed that ethanol evoked responses in W neurons that were strongly and selectively associated with activity to sweet stimuli, whereas responses to ethanol by P neurons were not easily associated with activity to representative sweet, sodium salt, acidic, or bitter stimuli. These findings show differential central neural representation of oral ethanol between genetically heterogeneous rats and P rats genetically selected to prefer alcohol. PMID:21918002

Differential neural representation of oral ethanol by central taste-sensitive neurons in ethanol-preferring and genetically heterogeneous rats.

PubMed

Lemon, Christian H; Wilson, David M; Brasser, Susan M

2011-12-01

In randomly bred rats, orally applied ethanol stimulates neural substrates for appetitive sweet taste. To study associations between ethanol's oral sensory characteristics and genetically mediated ethanol preference, we made electrophysiological recordings of oral responses (spike density) by taste-sensitive nucleus tractus solitarii neurons in anesthetized selectively bred ethanol-preferring (P) rats and their genetically heterogeneous Wistar (W) control strain. Stimuli (25 total) included ethanol [3%, 5%, 10%, 15%, 25%, and 40% (vol/vol)], a sucrose series (0.01, 0.03, 0.1, 0.3, 0.5, and 1 M), and other sweet, salt, acidic, and bitter stimuli; 50 P and 39 W neurons were sampled. k-means clustering applied to the sucrose response series identified cells showing high (S(1)) or relatively low (S(0)) sensitivity to sucrose. A three-way factorial analysis revealed that activity to ethanol was influenced by a neuron's sensitivity to sucrose, ethanol concentration, and rat line (P = 0.01). Ethanol produced concentration-dependent responses in S(1) neurons that were larger than those in S(0) cells. Although responses to ethanol by S(1) cells did not differ between lines, neuronal firing rates to ethanol in S(0) cells increased across concentration only in P rats. Correlation and multivariate analyses revealed that ethanol evoked responses in W neurons that were strongly and selectively associated with activity to sweet stimuli, whereas responses to ethanol by P neurons were not easily associated with activity to representative sweet, sodium salt, acidic, or bitter stimuli. These findings show differential central neural representation of oral ethanol between genetically heterogeneous rats and P rats genetically selected to prefer alcohol.

Analytical issues in the evaluation of food deprivation and sucrose concentration effects on the microstructure of licking behavior in the rat.

PubMed

Spector, A C; Klumpp, P A; Kaplan, J M

1998-06-01

A microstructural analysis of licking behavior in nondeprived and 23-hr food-deprived rats (n = 15) presented with various sucrose solutions (0.03-1.0 M) in daily single-bottle, 1-hr sessions was conducted. Food deprivation and concentration interacted to increase total licks. The effects of food deprivation and concentration on burst size (BS), burst number (BN), and other parameters varied as a function of the pause criterion (PC; 0.3-100 s) used to define licking bursts. A rationale for selecting a 1-s PC for further analysis is presented. Despite the lack of correlations between temporally contiguous burst and pause combinations, mean BS decreased and pause duration increased as meals progressed. At the 1-s PC, BS increased linearly with concentration, implying that this microstructural parameter is influenced in part by taste. Food deprivation did not affect BS but rather increased BN and proportionally extended the meal duration.

An evaluation of D-glucosamine as a gratuitous catabolite repressor of Saccharomyces carlsbergensis.

PubMed

Furst, A; Michels, C A

1977-10-24

Glucose represses mitochondrial biogenesis and the fermentation of maltose, galactose and sucrose in yeast. We have analyzed the effect of D-glucosamine on these functions in order to determine if it can produce a similar repression. It was found that glucosamine represses the respiration rate (QO2) but more rapidly than glucose and to a final level slightly higher than in glucose-treated cells. Derepression of the respiration rate following either glucose or glucosamine repression was similar. A two hour lag was followed by a linear increase in QO2 to the derepressed level. Both glucose and glucosamine repressed the level of cytochrome oxidase to the same level. Glucosamine was also found to repress maltose and galactose fermentation but not sucrose fermentation. The derepression of maltase synthesis was inhibited by glucosamine. The constitutive synthesis of maltase was repressed by the addition of glucosamine. Glucosamine was judged to produce a repressed state similar to glucose repression in many respects.

[Sugar triggers our reward-system. Sweets release opiates which stimulates the appetite for sucrose--insulin can depress it].

PubMed

Erlanson-Albertsson, Charlotte

The consumption of sweet food has increased in Sweden, as in other Western countries. The type of food item has changed. The sweet is dominated by soft drinks. Appetite regulation for sucrose has been described in experimental animal models. It has been found that opioids stimulate appetite for sucrose. At the same time sucrose releases endogenous opioids so that a triggering of sucrose consumption occurs. Insulin has been shown to decrease sucrose intake by blocking the opioid response. Sucrose addiction has been described in rat model. With a concentrated sucrose solution to drink an opioid dependence developed with 1) increased consumption of sucrose 2) abstinence symptoms with no sucrose and 3) anxiety with an opiate blocker. Sucrose addiction in man has not been described in the scientific literature. There is an increased liking of sweets with alcoholic persons, which may be significant to support a strongly rewarding effect of sucrose, also in man. We should limit the access to sweet foods, in particular the sweet drinks. Insulin and insulin sensitivity may be an important factor to restrict the intake of sweet food.

Observation of glassy state relaxation during annealing of frozen sugar solutions by X-ray computed tomography.

PubMed

Nakagawa, Kyuya; Tamiya, Shinri; Do, Gabsoo; Kono, Shinji; Ochiai, Takaaki

2018-06-01

Glassy phase formation in a frozen product determines various properties of the freeze-dried products. When an aqueous solution is subjected to freezing, a glassy phase forms as a consequence of freeze-concentration. During post-freezing annealing, the relaxation of the glassy phase and the ripening of ice crystals (i.e. Ostwald ripening) spontaneously occur, where the kinetics are controlled by the annealing and glass transition temperatures. This study was motivated to observe the progress of glassy state relaxation separate from ice coarsening during annealing. X-ray computed tomography (CT) was used to observe a frozen and post-freezing annealed solutions by using monochromatized X-ray from the synchrotron radiation. CT images were successfully obtained, and the frozen matrix were analyzed based on the gray level values that were equivalent to the linear X-ray attenuation coefficients of the observed matters. The CT images obtained from rapidly frozen sucrose and dextrin solutions with different concentrations gave clear linear relationships between the linear X-ray attenuation coefficients values and the solute concentrations. It was confirmed that the glassy state relaxation progressed as increasing annealing time, and this trend was larger in the order of the glass transition temperature of the maximally freeze-concentrated phase. The sucrose-water system required nearly 20 h of annealing time at -5 °C for the completion of the glassy phase relaxation, whereas dextrin-water systems required much longer periods because of their higher glass transition temperatures. The trends of ice coarsening, however, did not perfectly correspond to the trends of the relaxation, suggesting that the glassy phase relaxation and Ostwald ripening would jointly control the ice crystal growth/ripening kinetics, and the dominant mechanism differed by the annealing stage. Copyright © 2018 Elsevier B.V. All rights reserved.

Linear increases in carbon nanotube density through multiple transfer technique.

PubMed

Shulaker, Max M; Wei, Hai; Patil, Nishant; Provine, J; Chen, Hong-Yu; Wong, H-S P; Mitra, Subhasish

2011-05-11

We present a technique to increase carbon nanotube (CNT) density beyond the as-grown CNT density. We perform multiple transfers, whereby we transfer CNTs from several growth wafers onto the same target surface, thereby linearly increasing CNT density on the target substrate. This process, called transfer of nanotubes through multiple sacrificial layers, is highly scalable, and we demonstrate linear CNT density scaling up to 5 transfers. We also demonstrate that this linear CNT density increase results in an ideal linear increase in drain-source currents of carbon nanotube field effect transistors (CNFETs). Experimental results demonstrate that CNT density can be improved from 2 to 8 CNTs/μm, accompanied by an increase in drain-source CNFET current from 4.3 to 17.4 μA/μm.

Behavioral and hormonal responses to stress in binge-like eating prone female rats.

PubMed

Calvez, Juliane; Timofeeva, Elena

2016-04-01

Binge eating episodes are frequently stimulated by stress. We developed a model of binge eating proneness based on individual sensitivity of young female Sprague Dawley rats to significantly increase sucrose consumption in response to stress. The rats were subjected to unpredictable intermittent 1-h access to 10% sucrose. After the stabilization of sucrose intake, rats were assessed for consistency of higher (for binge-like eating prone, BEP) or lower (for binge-like eating resistant, BER) sucrose intake in response to unpredictable episodes of foot-shock stress. The objectives of this study included demonstrating face validity of the BEP model and determining if some of the features of this model were pre-existing before exposure to intermittent access to sucrose and repeated stress. The BEP rats consumed a larger (20%>BER) amount of sucrose in a discrete (1-h) period of time compared to the BER phenotype in non-stressful conditions and significantly increased sucrose intake (50%>BER) under stress. Conversely, stress did not affect sucrose intake in BER rats. BEP rats showed higher sucrose intake compared to BER rats at the beginning of darkness as well as during the light period when they were sated and not physically hungry. Analyses of the sucrose licking microstructure revealed that BEP rats had a high motivational drive to consume sucrose in non-stressful condition and an increased hedonic value of sucrose when they were exposed to stressful conditions. BEP rats consumed sucrose much more rapidly under stressful conditions compared to BER rats. Finally, BEP rats demonstrated compulsive-like intake of sucrose (assessed in the light-dark box) and a blunted stress-induced increase in plasma corticosterone levels. Body weight and chow intake were not different between the phenotypes. Before exposure to intermittent access to sucrose and repeated stress, the BEP rats showed no clear evidence for compulsive sucrose intake. However, from the first 1-h access to sucrose, the BEP rats exhibited sucrose overeating; and from the first exposure to stress before intermittent access to sucrose, the BEP rats showed a blunted increase in corticosterone plasma levels. Innate sucrose hyperconsumption and altered reactivity of the hypothalamo-pituitary adrenal (HPA) axis to stress may be involved in the development of binge-like eating. Increased perceived hedonic value of palatable food and an increased motivation to consume this food despite aversive conditions as well as deregulated reactivity of the HPA axis may contribute to stress-induced bingeing on sucrose in BEP rats. Copyright © 2016 Elsevier Inc. All rights reserved.

Sucrose secreted by the engineered cyanobacterium and its fermentability

NASA Astrophysics Data System (ADS)

Duan, Yangkai; Luo, Quan; Liang, Feiyan; Lu, Xuefeng

2016-10-01

The unicellular cyanobacterium, Synechococcus elongatus PCC 7942 (Syn7942), synthesizes sucrose as the only compatible solute under salt stress. A series of engineered Syn7942 strains for sucrose production were constructed. The overexpression of the native sps (encoding a natively fused protein of sucrose phosphate synthase SPS and sucrose phosphate phosphatase SPP) in Syn7942 wild type caused a 93% improvement of sucrose productivity. The strain FL130 co-overexpressing sps and cscB (encoding a sucrose transporter) exhibited a 74% higher extracellular sucrose production than that overexpressing cscB only. Both results showed the significant improvement of sucrose productivity by the double functional protein SPS-SPP. Afterwards, FL130 was cultivated under a modified condition, and the cell-free culture medium containing 1.5 g L-1 sucrose was pre-treated with an acid hydrolysis technique. Cultivated with the neutralized hydrolysates as the starting media, two widely used microorganisms, Escherichia coli and Saccharomyces cerevisiae, showed a comparable growth with that in the control media supplemented with glucose. These results clearly demonstrated that the cell-free culture of sucrose-secreting cyanobacteria can be applied as starting media in microbial cultivation.

Analysis of sucrose-induced small RNAs in Streptococcus mutans in the presence of different sucrose concentrations.

PubMed

Liu, Shan Shan; Zhu, Wen Hui; Zhi, Qing Hui; Liu, Jia; Wang, Yan; Lin, Huan Cai

2017-07-01

Streptococcus mutans (S. mutans) is the major pathogen contributing to dental caries. Sucrose is an important carbohydrate source for S. mutans and is crucial for dental caries. Small RNAs (sRNAs) are key post-transcriptional regulators of stress adaptation and virulence in bacteria. Here, for the first time, we created three replicate RNA libraries exposed to either 1 or 5% sucrose. The expression levels of sRNAs and target genes (gtfB, gtfC, and spaP) related to virulence were assessed. In addition, some phenotypic traits were evaluated. We obtained 2125 sRNA candidates with at least 100 average reads in 1% sucrose or 5% sucrose. Of these candidates, 2 were upregulated and 20 were downregulated in 1% sucrose. Six of these 22 differentially expressed sRNAs were validated by qRT-PCR. The expression level of target gene gtfB was higher in 1% sucrose. The adherence ratio of S. mutans was higher in 1% sucrose than in 5% sucrose. The synthesis of water-insoluble glucans (WIGs) was significantly higher in 5% sucrose than in 1% sucrose. These data suggest that a series of sRNAs can be induced in response to sucrose, and that some sRNAs might be involved in the regulation of phenotypes, providing new insight into the prevention of caries.

The effects of fruiting positions on cellulose synthesis and sucrose metabolism during cotton (Gossypium hirsutum L.) fiber development.

PubMed

Ma, Yina; Wang, Youhua; Liu, Jingran; Lv, Fengjuan; Chen, Ji; Zhou, Zhiguo

2014-01-01

Cotton (Gossypium hirsutum L.) boll positions on a fruiting branch vary in their contribution to yield and fiber quality. Fiber properties are dependent on deposition of cellulose in the fiber cell wall, but information about the enzymatic differences in sucrose metabolism between these fruiting positions is lacking. Therefore, two cotton cultivars with different sensitivities to low temperature were tested in 2010 and 2011 to quantify the effect of fruit positions (FPs) on fiber quality in relation to sucrose content, enzymatic activities and sucrose metabolism. The indices including sucrose content, sucrose transformation rate, cellulose content, and the activities of the key enzymes, sucrose phosphate synthase (SPS), acid invertase (AI) and sucrose synthase (SuSy) which inhibit cellulose synthesis and eventually affect fiber quality traits in cotton fiber, were determined. Results showed that as compared with those of FP1, cellulose content, sucrose content, and sucrose transformation rate of FP3 were all decreased, and the variations of cellulose content and sucrose transformation rate caused by FPs in Sumian 15 were larger than those in Kemian 1. Under FP effect, activities of SPS and AI in sucrose regulation were decreased, while SuSy activity in sucrose degradation was increased. The changes in activities of SuSy and SPS in response to FP effect displayed different and large change ranges between the two cultivars. These results indicate that restrained cellulose synthesis and sucrose metabolism in distal FPs are mainly attributed to the changes in the activities of these enzymes. The difference in fiber quality, cellulose synthesis and sucrose metabolism in response to FPs in fiber cells for the two cotton cultivars was mainly determined by the activities of both SuSy and SPS.

Starch Combined with Sucrose Provokes Greater Root Dentine Demineralization than Sucrose Alone.

PubMed

Souza, Samilly Evangelista; Sampaio, Aline Araújo; Del Bel Cury, Altair Antoninha; Cavalcanti, Yuri Wanderley; Ricomini Filho, Antônio Pedro; Cury, Jaime Aparecido

2018-02-14

Since there is no consensus about whether starch increases the cariogenic potential of sucrose, we used a validated 3-species biofilm model to evaluate if starch combined with sucrose provokes higher root dentine demineralization than sucrose alone. Biofilms (n = 18) composed by Streptococcus mutans (the most cariogenic bacteria), Actinomces naeslundii (which has amylolytic activity), and Streptococcus gordonii (which binds salivary amylase) were formed on root dentine slabs under exposure 8 ×/day to one of the following treatments: 0.9% NaCl, 1% starch, 10% sucrose, or a combination of 1% starch and 10% sucrose. Before each treatment, biofilms were pretreated with human whole saliva for 1 min. The pH of the culture medium was measured daily as an indicator of biofilm acidogenicity. After 96 h of growth, the biofilms were collected, and the biomass, bacteria viability, and polysaccharides were analyzed. Dentine demineralization was assessed by surface hardness loss (% SHL). Biofilm bioarchitecture was analyzed using confocal laser scanning microscopy. Treatment with a starch and sucrose combination provoked higher (p = 0.01) dentine demineralization than sucrose alone (% SHL = 53.2 ± 7.0 vs. 43.2 ± 8.7). This was supported by lower pH values (p = 0.007) of the culture medium after daily exposure to the starch and sucrose combination compared with sucrose (4.89 ± 0.29 vs. 5.19 ± 0.32). Microbiological and biochemical findings did not differ between biofilms treated with the combination of starch and sucrose and sucrose alone (p > 0.05). Our findings give support to the hypothesis that a starch and sucrose combination is more cariogenic for root dentine than sucrose alone. © 2018 S. Karger AG, Basel.

Deconstructing the vanilla milkshake: the dominant effect of sucrose on self-administration of nutrient-flavor mixtures.

PubMed

Naleid, Amy M; Grimm, Jeffrey W; Kessler, David A; Sipols, Alfred J; Aliakbari, Sepideh; Bennett, Jennifer L; Wells, Jason; Figlewicz, Dianne P

2008-01-01

Rats and humans avidly consume flavored foods that contain sucrose and fat, presumably due to their rewarding qualities. In this study, we hypothesized that the complex mixture of corn oil, sucrose, and flavor is more reinforcing than any of these components alone. We observed a concentration-dependent increase in reinforcers of sucrose solutions received (0%, 3%, 6.25%, and 12.5%) in both fixed ratio and progressive ratio procedures, but with equicaloric corn oil solutions (0%, 1.4%, 2.8%, and 5.6%) this finding was replicated only in the fixed ratio procedure. Likewise, addition of 1.4% oil to 3% or 12.5% sucrose increased fixed ratio, but not progressive ratio, reinforcers received relative to those of sucrose alone. Finally, addition of 3% vanilla flavoring did not change self-administration of 3% sucrose or 3% sucrose+1.4% oil solutions. These data suggest that, calorie-for-calorie, sucrose is the dominant reinforcing component of novel foods that contain a mixture of fat, sucrose, and flavor.

The Structure of Sucrose Synthase-1 from Arabidopsis thaliana and Its Functional Implications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zheng, Yi; Anderson, Spencer; Zhang, Yanfeng

2014-10-02

Sucrose transport is the central system for the allocation of carbon resources in vascular plants. During growth and development, plants control carbon distribution by coordinating sites of sucrose synthesis and cleavage in different plant organs and different cellular locations. Sucrose synthase, which reversibly catalyzes sucrose synthesis and cleavage, provides a direct and reversible means to regulate sucrose flux. Depending on the metabolic environment, sucrose synthase alters its cellular location to participate in cellulose, callose, and starch biosynthesis through its interactions with membranes, organelles, and cytoskeletal actin. The x-ray crystal structure of sucrose synthase isoform 1 from Arabidopsis thaliana (AtSus1) hasmore » been determined as a complex with UDP-glucose and as a complex with UDP and fructose, at 2.8- and 2.85-{angstrom} resolutions, respectively. The AtSus1 structure provides insights into sucrose catalysis and cleavage, as well as the regulation of sucrose synthase and its interactions with cellular targets.« less

Effects of resource availability and propagule supply on native species recruitment in sagebrush ecosystems invaded by Bromus tectorum

USGS Publications Warehouse

Mazzola, Monica B.; Chambers, Jeanne C.; Blank, Robert R.; Pyke, David A.; Schupp, Eugene W.; Allcock, Kimberly G.; Doescher, Paul S.; Nowak, Robert S.

2011-01-01

Resource availability and propagule supply are major factors influencing establishment and persistence of both native and invasive species. Increased soil nitrogen (N) availability and high propagule inputs contribute to the ability of annual invasive grasses to dominate disturbed ecosystems. Nitrogen reduction through carbon (C) additions can potentially immobilize soil N and reduce the competitiveness of annual invasive grasses. Native perennial species are more tolerant of resource limiting conditions and may benefit if N reduction decreases the competitive advantage of annual invaders and if sufficient propagules are available for their establishment. Bromus tectorum, an exotic annual grass in the sagebrush steppe of western North America, is rapidly displacing native plant species and causing widespread changes in ecosystem processes. We tested whether nitrogen reduction would negatively affect B. tectorum while creating an opportunity for establishment of native perennial species. A C source, sucrose, was added to the soil, and then plots were seeded with different densities of both B. tectorum (0, 150, 300, 600, and 1,200 viable seeds m-2) and native species (0, 150, 300, and 600 viable seeds m-2). Adding sucrose had short-term (1 year) negative effects on available nitrogen and B. tectorum density, biomass and seed numbers, but did not increase establishment of native species. Increasing propagule availability increased both B. tectorum and native species establishment. Effects of B. tectorum on native species were density dependent and native establishment increased as B. tectorum propagule availability decreased. Survival of native seedlings was low indicating that recruitment is governed by the seedling stage.

The Central Role of the Matrix Protein in Nipah Virus Assembly and Morphogenesis

DTIC Science & Technology

2007-03-23

as determined by sucrose density gradient flotation and immunoprecipitation analysis. However, co-expression of F and G along with M revealed a...total protein detected (total lysate + supernatant). Experiments described in Chapter 4 did not 35 include a flotation step. Rather, following...culture supernatant were prepared as described above except the top 1.4 ml of the flotation gradient was mixed with 3 ml of PBS and centrifuged for an

In vivo transport of three radioactive [18F]-fluorinated deoxysucrose analogs by the maize sucrose transporter ZmSUT1.

PubMed

Tran, Thu M; Hampton, Carissa S; Brossard, Tom W; Harmata, Michael; Robertson, J David; Jurisson, Silvia S; Braun, David M

2017-06-01

Sucrose transporter (SUT) proteins translocate sucrose across cell membranes; however, mechanistic aspects of sucrose binding by SUTs are not well resolved. Specific hydroxyl groups in sucrose participate in hydrogen bonding with SUT proteins. We previously reported that substituting a radioactive fluorine-18 [ 18 F] at the C-6' position within the fructosyl moiety of sucrose did not affect sucrose transport by the maize (Zea mays) ZmSUT1 protein. To determine how 18 F substitution of hydroxyl groups at two other positions within sucrose, the C-1' in the fructosyl moiety or the C-6 in the glucosyl moiety, impact sucrose transport, we synthesized 1'-[F 18 ]fluoro-1'-deoxysucrose and 6-[F 18 ]fluoro-6-deoxysucrose ([ 18 F]FDS) analogs. Each [ 18 F]FDS derivative was independently introduced into wild-type or sut1 mutant plants, which are defective in sucrose phloem loading. All three (1'-, 6'-, and 6-) [ 18 F]FDS derivatives were efficiently and equally translocated, similarly to carbon-14 [ 14 C]-labeled sucrose. Hence, individually replacing the hydroxyl groups at these positions within sucrose does not interfere with substrate recognition, binding, or membrane transport processes, and hydroxyl groups at these three positions are not essential for hydrogen bonding between sucrose and ZmSUT1. [ 18 F]FDS imaging afforded several advantages compared to [ 14 C]-sucrose detection. We calculated that 1'-[ 18 F]FDS was transported at approximately a rate of 0.90 ± 0.15 m.h-1 in wild-type leaves, and at 0.68 ± 0.25 m.h-1 in sut1 mutant leaves. Collectively, our data indicated that [ 18 F]FDS analogs are valuable tools to probe sucrose-SUT interactions and to monitor sucrose transport in plants. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Sucrose metabolic pathways in sweetgum and pecan seedlings

Treesearch

S.S. Sung; P.P. Kormanik; D.P. Xu; C.C. Black

1989-01-01

Sucrose metabolism and glycolysis were studied in one- to two-year-old seedlings of sweetgum (Liquidambar styraciflua L.) and pecan (Carya illinoinensis (Wangenh.) C. Koch). The sucrose synthase pathway was identified as the dominant sucrose metabolic activity in sucrose sink tissues such as terminal buds and the root cambial...

Succinic acid production from sucrose by Actinobacillus succinogenes NJ113.

PubMed

Jiang, Min; Dai, Wenyu; Xi, Yonglan; Wu, Mingke; Kong, Xiangping; Ma, Jiangfeng; Zhang, Min; Chen, Kequan; Wei, Ping

2014-02-01

In this study, sucrose, a reproducible disaccharide extracted from plants, was used as the carbon source for the production of succinic acid by Actinobacillus succinogenes NJ113. During serum bottle fermentation, the succinic acid concentration reached 57.1g/L with a yield of 71.5%. Further analysis of the sucrose utilization pathways revealed that sucrose was transported and utilized via a sucrose phosphotransferase system, sucrose-6-phosphate hydrolase, and a fructose PTS. Compared to glucose utilization in single pathway, more pathways of A. succinogenes NJ113 are dependent on sucrose utilization. By changing the control strategy in a fed-batch culture to alleviate sucrose inhibition, 60.5g/L of succinic acid was accumulated with a yield of 82.9%, and the productivity increased by 35.2%, reaching 2.16g/L/h. Thus utilization of sucrose has considerable potential economics and environmental meaning. Copyright © 2014 Elsevier Ltd. All rights reserved.

Dissecting genomic hotspots underlying seed protein, oil, and sucrose content in an interspecific mapping population of soybean using high-density linkage mapping.

PubMed

Patil, Gunvant; Vuong, Tri D; Kale, Sandip; Valliyodan, Babu; Deshmukh, Rupesh; Zhu, Chengsong; Wu, Xiaolei; Bai, Yonghe; Yungbluth, Dennis; Lu, Fang; Kumpatla, Siva; Shannon, J Grover; Varshney, Rajeev K; Nguyen, Henry T

2018-04-04

The cultivated [Glycine max (L) Merr.] and wild [Glycine soja Siebold & Zucc.] soybean species comprise wide variation in seed composition traits. Compared to wild soybean, cultivated soybean contains low protein, high oil, and high sucrose. In this study, an interspecific population was derived from a cross between G. max (Williams 82) and G. soja (PI 483460B). This recombinant inbred line (RIL) population of 188 lines was sequenced at 0.3× depth. Based on 91 342 single nucleotide polymorphisms (SNPs), recombination events in RILs were defined, and a high-resolution bin map was developed (4070 bins). In addition to bin mapping, quantitative trait loci (QTL) analysis for protein, oil, and sucrose was performed using 3343 polymorphic SNPs (3K-SNP), derived from Illumina Infinium BeadChip sequencing platform. The QTL regions from both platforms were compared, and a significant concordance was observed between bin and 3K-SNP markers. Importantly, the bin map derived from next-generation sequencing technology enhanced mapping resolution (from 1325 to 50 Kb). A total of five, nine, and four QTLs were identified for protein, oil, and sucrose content, respectively, and some of the QTLs coincided with soybean domestication-related genomic loci. The major QTL for protein and oil were mapped on Chr. 20 (qPro_20) and suggested negative correlation between oil and protein. In terms of sucrose content, a novel and major QTL were identified on Chr. 8 (qSuc_08) and harbours putative genes involved in sugar transport. In addition, genome-wide association using 91 342 SNPs confirmed the genomic loci derived from QTL mapping. A QTL-based haplotype using whole-genome resequencing of 106 diverse soybean lines identified unique allelic variation in wild soybean that could be utilized to widen the genetic base in cultivated soybean. © 2018 The Authors. Plant Biotechnology Journal published by Society for Experimental Biology and The Association of Applied Biologists and John Wiley & Sons Ltd.

Conditional suicide system of Escherichia coli released into soil that uses the Bacillus subtilis sacB gene.

PubMed Central

Recorbet, G; Robert, C; Givaudan, A; Kudla, B; Normand, P; Faurie, G

1993-01-01

The sacB gene from Bacillus subtilis confers sucrose sensitivity upon gram-negative bacteria. The gene was investigated for use as a potential conditional suicide system for Escherichia coli released into soil. To ensure against the loss of the cell death function encoded under nonselective conditions, the nptI-sacR-B suicide cassette was inserted into the E. coli chromosome by using a circular nonreplicative integration vector. Stability studies yielded no loss of the suicide cassette in the integrated E. coli EL1026 strain. sacB induction in the absence of a selective pressure resulted in a lysis efficiency of up to 99.9%. The microcosm experiments confirmed the ability of the suicide cassette to limit the growth and reduce the survival of E. coli strains released into soil. Sucrose addition to sterile soil resulted in a 10(-3)-fold reduction of the final E. coli population density. sacB induction prevented the proliferation and triggered the rapid disappearance of E. coli from natural soil. Mutation to sucrose tolerance occurred at a frequency of 10(-5), making E. coli EL1026 a potential counterselectable donor strain for gene transfer studies. Specificity and potential adaptability to a wide range of gram-negative bacteria are additional conveniences of this conditional suicide system for the containment and counterselection of engineered microorganisms. PMID:8517732

Conditional suicide system of Escherichia coli released into soil that uses the Bacillus subtilis sacB gene.

PubMed

Recorbet, G; Robert, C; Givaudan, A; Kudla, B; Normand, P; Faurie, G

1993-05-01

The sacB gene from Bacillus subtilis confers sucrose sensitivity upon gram-negative bacteria. The gene was investigated for use as a potential conditional suicide system for Escherichia coli released into soil. To ensure against the loss of the cell death function encoded under nonselective conditions, the nptI-sacR-B suicide cassette was inserted into the E. coli chromosome by using a circular nonreplicative integration vector. Stability studies yielded no loss of the suicide cassette in the integrated E. coli EL1026 strain. sacB induction in the absence of a selective pressure resulted in a lysis efficiency of up to 99.9%. The microcosm experiments confirmed the ability of the suicide cassette to limit the growth and reduce the survival of E. coli strains released into soil. Sucrose addition to sterile soil resulted in a 10(-3)-fold reduction of the final E. coli population density. sacB induction prevented the proliferation and triggered the rapid disappearance of E. coli from natural soil. Mutation to sucrose tolerance occurred at a frequency of 10(-5), making E. coli EL1026 a potential counterselectable donor strain for gene transfer studies. Specificity and potential adaptability to a wide range of gram-negative bacteria are additional conveniences of this conditional suicide system for the containment and counterselection of engineered microorganisms.

Structural development of sucrose-sweetened and sucrose-free sponge cakes during baking.

PubMed

Baeva, Marianna Rousseva; Terzieva, Vesselina Velichkova; Panchev, Ivan Nedelchev

2003-06-01

The influence of sucrose, wheat starch and sorbitol upon the heat- and mass-exchanging processes forming the structure of sponge cake was studied. Under the influence of wheat starch and sorbitol the structure of the sucrose-free sponge cake was formed at more uniform total moisture release. This process was done at lower temperatures and smoother change of the sponge cake height with respect to the sucrose-sweetened sponge cake. The porous and steady structure of both cakes was finally formed at identical time--between 18th and 19th minute, at the applied conditions for baking of each batter (metal pan with diameter 15.4 cm and depth 6.2 cm containing 300 g of batter and placed in an electric oven "Rahovetz-02", Bulgaria for 30 min at 180 degrees C). The water-losses at the end of baking (10.30% and 10.40% for the sucrose-sweetened cake and sucrose-free cake, respectively) and the final temperatures reached in the crumb central layers (96.6 degrees C and 96.3 degrees C for the sucrose-sweetened cake and sucrose-free cake, respectively) during baking of both samples were not statistically different. The addition of wheat starch and sorbitol in sucrose-free sponge cake lead to the statistically different values for the porosity (76.15% and 72.98%) and the volume (1014.17 cm3 and 984.25 cm3) of the sucrose-sweetened and sucrose-free sponge cakes, respectively. As a result, the sucrose-free sponge cake formed during baking had a more homogeneous and finer microstructure with respect to that ofthe sucrose-sweetened one.

Metabolic engineering to expand the substrate spectrum of Pseudomonas putida toward sucrose.

PubMed

Löwe, Hannes; Schmauder, Lukas; Hobmeier, Karina; Kremling, Andreas; Pflüger-Grau, Katharina

2017-08-01

Sucrose is an important disaccharide used as a substrate in many industrial applications. It is a major component of molasses, a cheap by-product of the sugar industry. Unfortunately, not all industrially relevant organisms, among them Pseudomonas putida, are capable of metabolizing sucrose. We chose a metabolic engineering approach to circumvent this blockage and equip P. putida with the activities necessary to consume sucrose. Therefore, we constructed a pair of broad-host range mini-transposons (pSST - sucrose splitting transposon), carrying either cscA, encoding an invertase able to split sucrose into glucose and fructose, or additionally cscB, encoding a sucrose permease. Introduction of cscA was sufficient to convey sucrose consumption and the additional presence of cscB had no further effect, though the sucrose permease was built and localized to the membrane. Sucrose was split extracellularly by the activity of the invertase CscA leaking out of the cell. The transposons were also used to confer sucrose consumption to Cupriavidus necator. Interestingly, in this strain, CscB acted as a glucose transporter, such that C. necator also gained the ability to grow on glucose. Thus, the pSST transposons are functional tools to extend the substrate spectrum of Gram-negative bacterial strains toward sucrose. © 2017 The Authors. MicrobiologyOpen published by John Wiley & Sons Ltd.

DECONSTRUCTING THE VANILLA MILKSHAKE: THE DOMINANT EFFECT OF SUCROSE ON SELF-ADMINISTRATION OF NUTRIENT-FLAVOR MIXTURES

PubMed Central

Naleid, Amy M.; Grimm, Jeffrey W.; Kessler, David A.; Sipols, Alfred J.; Aliakbari, Sepideh; Bennett, Jennifer L.; Wells, Jason; Figlewicz, Dianne P.

2007-01-01

Rats and humans avidly consume flavored foods that contain sucrose and fat, presumably due to their rewarding qualities. In this study, we hypothesized that the complex mixture of corn oil, sucrose, and flavor is more reinforcing than any of these components alone. We observed a concentration-dependent increase in reinforcers received of sucrose solutions (0, 3, 6.25, and 12.5%) in both fixed ratio and progressive ratio procedures, but with equicaloric corn oil solutions (0, 1.4, 2.8, and 5.6%) this finding was replicated only in the fixed ratio procedure. Likewise, addition of 1.4% oil to 3% or 12.5% sucrose increased fixed ratio, but not progressive ratio, reinforcers received relative to those of sucrose alone. Finally, addition of 3% vanilla flavoring did not change self-administration of 3% sucrose or 3% sucrose + 1.4% oil solutions. These data suggest that, calorie-for-calorie, sucrose is the dominant reinforcing component of novel foods that contain a mixture of fat, sucrose, and flavor. PMID:17707949

Composition, quaternary structure, and catalytic properties of D-ribulose-1, 5-bisphosphate carboxylase from Euglena gracilis.

PubMed

McFadden, B A; Lord, J M; Rowe, A; Dilks, S

1975-05-01

D-Ribulose-1,5-bisphosphate carboxylase has been purified in one step by sedimenting extracts of autotrophically-grown Euglena gracilis into a linear 0.2-0.8 M sucrose density gradient. The resultant product was pure by the criteria of disc electrophoresis in gels polymerized from 5 or 7.5% acrylamide and sedimentation. The molecular weight of the enzyme estimated by density gradient centrifugation and electrophoresis in gels polymerized from various concentrations of acrylamide was 5.25 X 10(5). The S20,W was 16.4 S. Dissociation and polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulphate established that the enzyme was composed of two types of subunits (mr 50,000 and 15,000). The oligomeric structure was visualized through negative staining and transmission electron microscopy leading to a model for the quaternary structure. Although the enzyme was moderately unstable, the estimated maximal specific activity was 1.6 mumol CO2 fixed min-1 mg protien-1 at 30 degrees C and pH 8.0 Km values were 2.2 m M, 15. 1 MUM and 0.63 mM for Mg2+, ribulose 1,5-bisphosphate, and CO2, respectively, when measured under air. 6-Phospho-D-gluconate was a noncompetitive inhibitor with respect to ribulose 1,5-bisphosphate (Ki = 0.04 mM). Oxygen was a competitive inhibitor with respect to CO2 suggesting that the enzyme was also an oxygenase. The latter was confirmed by experiments showing a molar equivalence between ribulose-1,5-bisphosphate-dependent oxygen consumption and phosphoglycerate production.

Development of sucrose-utilizing Escherichia coli K-12 strain by cloning β-fructofuranosidases and its application for L-threonine production.

PubMed

Lee, Jeong Wook; Choi, Sol; Park, Jin Hwan; Vickers, Claudia E; Nielsen, Lars K; Lee, Sang Yup

2010-10-01

Sucrose is one of the most promising carbon sources for industrial fermentation. To achieve sucrose catabolism, the sucrose utilization operons have been introduced into microorganisms that are not able to utilize sucrose. However, the rates of growth and sucrose uptake of these engineered strains were relatively low to be successfully employed for industrial applications. Here, we report a practical example of developing sucrose-utilizing microorganisms using Escherichia coli K-12 as a model system. The sucrose utilizing ability was acquired by introducing only β-fructofuranosidase from three different sucrose-utilizing organisms (Mannheimia succiniciproducens, E. coli W, and Bacillus subtilis). Among them, the M. succiniciproducens β-fructofuranosidase was found to be the most effective for sucrose utilization. Analyses of the underlying mechanism revealed that sucrose was hydrolyzed into glucose and fructose in the extracellular space and both liberated hexoses could be transported by their respective uptake systems in E. coli K-12. To prove that this system can also be applied for the production of useful metabolites, the M. succiniciproducens β-fructofuranosidase was introduced into the engineered L-threonine production strain of E. coli K-12. This recombinant strain was able to produce 51.1 g/L L-threonine by fed-batch culture, resulting in an overall yield of 0.284 g L-threonine per g sucrose. This simple approach to make E. coli K-12 to acquire sucrose-utilizing ability and its successful biotechnological application can be employed to develop sustainable bioprocesses using renewable biomass.

Sucrose breakdown within guard cells provides substrates for glycolysis and glutamine biosynthesis during light-induced stomatal opening.

PubMed

Medeiros, David B; Perez Souza, Leonardo; Antunes, Werner C; Araújo, Wagner L; Daloso, Danilo M; Fernie, Alisdair R

2018-05-01

Sucrose has long been thought to play an osmolytic role in stomatal opening. However, recent evidence supports the idea that the role of sucrose in this process is primarily energetic. Here we used a combination of stomatal aperture assays and kinetic [U- 13 C]-sucrose isotope labelling experiments to confirm that sucrose is degraded during light-induced stomatal opening and to define the fate of the C released from sucrose breakdown. We additionally show that addition of sucrose to the medium did not enhance light-induced stomatal opening. The isotope experiment showed a consistent 13 C enrichment in fructose and glucose, indicating that during light-induced stomatal opening sucrose is indeed degraded. We also observed a clear 13 C enrichment in glutamate and glutamine (Gln), suggesting a concerted activation of sucrose degradation, glycolysis and the tricarboxylic acid cycle. This is in contrast to the situation for Gln biosynthesis in leaves under light, which has been demonstrated to rely on previously stored C. Our results thus collectively allow us to redraw current models concerning the influence of sucrose during light-induced stomatal opening, in which, instead of being accumulated, sucrose is degraded providing C skeletons for Gln biosynthesis. © 2018 The Authors The Plant Journal © 2018 John Wiley & Sons Ltd.

Sucrose fermentation by Saccharomyces cerevisiae lacking hexose transport.

PubMed

Batista, Anderson S; Miletti, Luiz C; Stambuk, Boris U

2004-01-01

Sucrose is the major carbon source used by Saccharomyces cerevisiae during production of baker's yeast, fuel ethanol and several distilled beverages. It is generally accepted that sucrose fermentation proceeds through extracellular hydrolysis of the sugar, mediated by the periplasmic invertase, producing glucose and fructose that are transported into the cells and metabolized. In the present work we analyzed the contribution to sucrose fermentation of a poorly characterized pathway of sucrose utilization by S. cerevisiae cells, the active transport of the sugar through the plasma membrane and its intracellular hydrolysis. A yeast strain that lacks the major hexose transporters (hxt1-hxt7 and gal2) is incapable of growing on or fermenting glucose or fructose. Our results show that this hxt-null strain is still able to ferment sucrose due to direct uptake of the sugar into the cells. Deletion of the AGT1 gene, which encodes a high-affinity sucrose-H(+) symporter, rendered cells incapable of sucrose fermentation. Since sucrose is not an inducer of the permease, expression of the AGT1 must be constitutive in order to allow growth of the hxt-null strain on sucrose. The molecular characterization of active sucrose transport and fermentation by S. cerevisiae cells opens new opportunities to optimize yeasts for sugarcane-based industrial processes.

Sucrose acceptance, discrimination and proboscis responses of honey bees (Apis mellifera L.) in the field and the laboratory.

PubMed

Mujagic, Samir; Erber, Joachim

2009-04-01

Laboratory studies in honey bees have shown positive correlations between sucrose responsiveness, division of labour and learning. We tested the relationships between sucrose acceptance and discrimination in the field and responsiveness in the laboratory. Based on acceptance in the field three groups of bees were differentiated: (1) bees that accept sucrose concentrations >10%, (2) bees that accept some but not all of the sucrose concentrations <10% and water, and (3) bees that accept water and all offered sucrose concentrations. Sucrose acceptance can be described in a model in which sucrose- and water-dependent responses interact additively. Responsiveness to sucrose was tested in the same bees in the laboratory by measuring the proboscis extension response (PER). The experiments demonstrated that PER responsiveness is lower than acceptance in the field and that it is not possible to infer from the PER measurements in the laboratory those concentrations the respective bees accepted in the field. Discrimination between sucrose concentrations was tested in three groups of free-flying bees collecting low, intermediate or high concentrations of sucrose. The experiments demonstrated that bees can discriminate between concentrations differences down to 0.2 relative log units. There exist only partial correlations between discrimination, acceptance and PER responsiveness.

Sucrose accumulation in sweet sorghum stems occurs by apoplasmic phloem unloading and does not involve differential Sucrose transporter expression.

PubMed

Bihmidine, Saadia; Baker, R Frank; Hoffner, Cassandra; Braun, David M

2015-07-30

Sorghum (Sorghum bicolor L. Moench) cultivars store non-structural carbohydrates predominantly as either starch in seeds (grain sorghums) or sugars in stems (sweet sorghums). Previous research determined that sucrose accumulation in sweet sorghum stems was not correlated with the activities of enzymes functioning in sucrose metabolism, and that an apoplasmic transport step may be involved in stem sucrose accumulation. However, the sucrose unloading pathway from stem phloem to storage parenchyma cells remains unelucidated. Sucrose transporters (SUTs) transport sucrose across membranes, and have been proposed to function in sucrose partitioning differences between sweet and grain sorghums. The purpose of this study was to characterize the key differences in carbohydrate accumulation between a sweet and a grain sorghum, to define the path sucrose may follow for accumulation in sorghum stems, and to determine the roles played by sorghum SUTs in stem sucrose accumulation. Dye tracer studies to determine the sucrose transport route revealed that, for both the sweet sorghum cultivar Wray and grain sorghum cultivar Macia, the phloem in the stem veins was symplasmically isolated from surrounding cells, suggesting sucrose was apoplasmically unloaded. Once in the phloem apoplasm, a soluble tracer diffused from the vein to stem parenchyma cell walls, indicating the lignified mestome sheath encompassing the vein did not prevent apoplasmic flux outside of the vein. To characterize carbohydrate partitioning differences between Wray and Macia, we compared the growth, stem juice volume, solute contents, SbSUTs gene expression, and additional traits. Contrary to previous findings, we detected no significant differences in SbSUTs gene expression within stem tissues. Phloem sieve tubes within sweet and grain sorghum stems are symplasmically isolated from surrounding cells; hence, unloading from the phloem likely occurs apoplasmically, thereby defining the location of the previously postulated step for sucrose transport. Additionally, no changes in SbSUTs gene expression were detected in sweet vs. grain sorghum stems, suggesting alterations in SbSUT transcript levels do not account for the carbohydrate partitioning differences between cultivars. A model illustrating sucrose phloem unloading and movement to stem storage parenchyma, and highlighting roles for sucrose transport proteins in sorghum stems is discussed.

Variational and robust density fitting of four-center two-electron integrals in local metrics

NASA Astrophysics Data System (ADS)

Reine, Simen; Tellgren, Erik; Krapp, Andreas; Kjærgaard, Thomas; Helgaker, Trygve; Jansik, Branislav; Høst, Stinne; Salek, Paweł

2008-09-01

Density fitting is an important method for speeding up quantum-chemical calculations. Linear-scaling developments in Hartree-Fock and density-functional theories have highlighted the need for linear-scaling density-fitting schemes. In this paper, we present a robust variational density-fitting scheme that allows for solving the fitting equations in local metrics instead of the traditional Coulomb metric, as required for linear scaling. Results of fitting four-center two-electron integrals in the overlap and the attenuated Gaussian damped Coulomb metric are presented, and we conclude that density fitting can be performed in local metrics at little loss of chemical accuracy. We further propose to use this theory in linear-scaling density-fitting developments.

Variational and robust density fitting of four-center two-electron integrals in local metrics.

PubMed

Reine, Simen; Tellgren, Erik; Krapp, Andreas; Kjaergaard, Thomas; Helgaker, Trygve; Jansik, Branislav; Host, Stinne; Salek, Paweł

2008-09-14

Density fitting is an important method for speeding up quantum-chemical calculations. Linear-scaling developments in Hartree-Fock and density-functional theories have highlighted the need for linear-scaling density-fitting schemes. In this paper, we present a robust variational density-fitting scheme that allows for solving the fitting equations in local metrics instead of the traditional Coulomb metric, as required for linear scaling. Results of fitting four-center two-electron integrals in the overlap and the attenuated Gaussian damped Coulomb metric are presented, and we conclude that density fitting can be performed in local metrics at little loss of chemical accuracy. We further propose to use this theory in linear-scaling density-fitting developments.

Expression analysis of genes associated with sucrose accumulation in sugarcane (Saccharum spp. hybrids) varieties differing in content and time of peak sucrose storage

USDA-ARS?s Scientific Manuscript database

Sucrose synthesis/accumulation in sugarcane is a complex process involving many genes and regulatory sequences that control biochemical events in source-sink tissues. Among these, sucrose synthase (SuSy), sucrose-phosphate synthase (SPS), soluble acid (SAI) and cell-wall invertase (CWI) are importan...

Structure-function relationships of family GH70 glucansucrase and 4,6-α-glucanotransferase enzymes, and their evolutionary relationships with family GH13 enzymes.

PubMed

Meng, Xiangfeng; Gangoiti, Joana; Bai, Yuxiang; Pijning, Tjaard; Van Leeuwen, Sander S; Dijkhuizen, Lubbert

2016-07-01

Lactic acid bacteria (LAB) are known to produce large amounts of α-glucan exopolysaccharides. Family GH70 glucansucrase (GS) enzymes catalyze the synthesis of these α-glucans from sucrose. The elucidation of the crystal structures of representative GS enzymes has advanced our understanding of their reaction mechanism, especially structural features determining their linkage specificity. In addition, with the increase of genome sequencing, more and more GS enzymes are identified and characterized. Together, such knowledge may promote the synthesis of α-glucans with desired structures and properties from sucrose. In the meantime, two new GH70 subfamilies (GTFB- and GTFC-like) have been identified as 4,6-α-glucanotransferases (4,6-α-GTs) that represent novel evolutionary intermediates between the family GH13 and "classical GH70 enzymes". These enzymes are not active on sucrose; instead, they use (α1 → 4) glucans (i.e. malto-oligosaccharides and starch) as substrates to synthesize novel α-glucans by introducing linear chains of (α1 → 6) linkages. All these GH70 enzymes are very interesting biocatalysts and hold strong potential for applications in the food, medicine and cosmetic industries. In this review, we summarize the microbiological distribution and the structure-function relationships of family GH70 enzymes, introduce the two newly identified GH70 subfamilies, and discuss evolutionary relationships between family GH70 and GH13 enzymes.

Changes in physicochemical characteristics and free amino acids of hawthorn (Crataegus pinnatifida) fruits during maturation.

PubMed

Li, Wei-Qin; Hu, Qing-Ping; Xu, Jian-Guo

2015-05-15

In this study, changes in physicochemical characteristics associated with fruit quality and free amino acids were investigated during maturation of hawthorn fruits. Significant differences in these parameters were found during maturation. The color turned progressively from mature green to semi-red, to reach bright red; the shape changed gradually from oval to round or approached round; the size, weight, and edible part (flesh/core ratio) of hawthorns increased while the density of intact fruits did not change. The content of moisture, total soluble sugars, soluble pectin, reduced ascorbic acid, total ascorbic acid, fructose, and sucrose increased while crude protein content decreased significantly. The levels of starch, sucrose, titratable acidity, protopectin, pectin, total free amino acids, and total essential amino acids initially increased and then decreased gradually during maturation. The outcomes of this study provide additional and useful information for fresh consumption and processing as well as utilization of dropped unripe hawthorn fruits. Copyright © 2014 Elsevier Ltd. All rights reserved.

Quasi-linear regime of gravitational instability: Implication to density-velocity relation

NASA Technical Reports Server (NTRS)

Shandarin, Sergei F.

1993-01-01

The well known linear relation between density and peculiar velocity distributions is a powerful tool for studying the large-scale structure in the Universe. Potentially it can test the gravitational instability theory and measure Omega. At present it is used in both ways: the velocity is reconstructed, provided the density is given, and vice versa. Reconstructing the density from the velocity field usually makes use of the Zel'dovich approximation. However, the standard linear approximation in Eulerian space is used when the velocity is reconstructed from the density distribution. I show that the linearized Zel'dovich approximation, in other words the linear approximation in the Lagrangian space, is more accurate for reconstructing velocity. In principle, a simple iteration technique can recover both the density and velocity distributions in Lagrangian space, but its practical application may need an additional study.

Neohesperidin dihydrochalcone is not a taste enhancer in aqueous sucrose solutions.

PubMed

Kroeze, J H

2000-10-01

Neohesperidin dihydrochalcone (NHDC) is an intensive sweetener, obtained by alkaline hydrogenation of neohesperidin. In this investigation a supposed taste enhancing effect of this substance was tested. A three-step procedure was used. In the first experiment, using a pool of 31 subjects, NHDC and sucrose detection thresholds were measured. In the second experiment, psychophysical functions for both tastants were determined. Then, 15 participants closest to the group threshold who, in addition, had produced monotonic psychophysical taste functions were selected to participate in the next two experiments. In the third experiment, taste enhancement was tested. Three psychophysical sucrose functions were constructed, one with a near-threshold amount of NHDC added to each of seven sucrose concentrations, one with a near-threshold amount of sucrose added (control 1) and one without any addition (control 2). No difference was found between the NHDC-enriched sucrose function and the sucrose-enriched sucrose function. Finally, in experiment 4, differential threshold functions were constructed with either NHDC or sucrose added. Neither the overall shape of the functions nor a comparison of the points of subjective equality showed enhancement. It was concluded that weak NHDC does not enhance the taste of aqueous sucrose solutions.

Exposure to sucrose during periods of withdrawal does not reduce cocaine-seeking behavior in rats.

PubMed

Nicolas, Céline; Lafay-Chebassier, Claire; Solinas, Marcello

2016-03-21

Concomitant access to drugs of abuse and alternative rewards such as sucrose has been shown to decrease addiction-related behaviors in animals. Here we investigated whether access to sucrose during abstinence in contexts that are temporally and physically distinct from drug-related contexts could reduce subsequent drug seeking. In addition, we investigated whether a history of cocaine self-administration would alter the rewarding effects of sucrose. Rats self-administered cocaine for ten sessions, while yoked-saline rats received only saline injections, and then we subjected them to a 30-day withdrawal period during which they had access to water and sucrose continuously or intermittently according to a schedule that induces binge-drinking behavior. At the end of the withdrawal period, rats were tested for cocaine seeking behavior during a single 6 h session. We found that exposure to cocaine increased sucrose consumption only when rats had intermittent access to sucrose, but exposure to sucrose did not alter drug seeking regardless of the schedule of access. These results suggest that exposure to cocaine cross-sensitizes to the rewarding effects of sucrose, but exposure to sucrose during abstinence, temporally and physically distinct from drug-related environments, does not to reduce drug seeking.

Nutritional Control of Regreening and Degreening in Citrus Peel Segments 1

PubMed Central

Huff, Albert

1983-01-01

A method for reversibly regreening and degreening citrus epicarp in vitro using peel segments was developed. Peel segments from mature degreened fruit promptly regreened when kept in light upon agar medium containing low (15 millimolar) concentrations of sucrose. Higher concentrations of sucrose inhibited this regreening, but NO3− and certain amino acids included in the media overcame the inhibition by sucrose. However, l-serine strongly inhibited regreening. In the presence of nitrogen, sucrose promoted regreening. Peel segments from green fruit remained green on media with low concentrations of sucrose and on media with high concentrations of sucrose and 60 millimolar KNO3, but degreened in response to high concentrations of sucrose in the absence of nitrogen. Nitrate overcame the degreening effects of high sucrose concentrations in both light and dark. Peel segments were reversibly degreened and regreened by transferring the segments between appropriate media. Nitrate in the media markedly reduced the levels of endogenous sugars in the epicarp and increased endogenous amino acid levels. Sucrose in the media increased endogenous sugar levels and, in the presence of nitrate, increased endogenous amino acid levels. In the absence of nitrogen, high sucrose concentrations reduced endogenous amino acid concentrations. PMID:16663202

Body weight manipulation, reinforcement value and choice between sucrose and wheel running: a behavioral economic analysis.

PubMed

Belke, Terry W; Pierce, W David

2009-02-01

Twelve female Long-Evans rats were exposed to concurrent variable (VR) ratio schedules of sucrose and wheel-running reinforcement (Sucrose VR 10 Wheel VR 10; Sucrose VR 5 Wheel VR 20; Sucrose VR 20 Wheel VR 5) with predetermined budgets (number of responses). The allocation of lever pressing to the sucrose and wheel-running alternatives was assessed at high and low body weights. Results showed that wheel-running rate and lever-pressing rates for sucrose and wheel running increased, but the choice of wheel running decreased at the low body weight. A regression analysis of relative consumption as a function of relative price showed that consumption shifted toward sucrose and interacted with price differences in a manner consistent with increased substitutability. Demand curves showed that demand for sucrose became less elastic while demand for wheel running became more elastic at the low body weight. These findings reflect an increase in the difference in relative value of sucrose and wheel running as body weight decreased. Discussion focuses on the limitations of response rates as measures of reinforcement value. In addition, we address the commonalities between matching and demand curve equations for the analysis of changes in relative reinforcement value.

Estimating cosmic velocity fields from density fields and tidal tensors

NASA Astrophysics Data System (ADS)

Kitaura, Francisco-Shu; Angulo, Raul E.; Hoffman, Yehuda; Gottlöber, Stefan

2012-10-01

In this work we investigate the non-linear and non-local relation between cosmological density and peculiar velocity fields. Our goal is to provide an algorithm for the reconstruction of the non-linear velocity field from the fully non-linear density. We find that including the gravitational tidal field tensor using second-order Lagrangian perturbation theory based upon an estimate of the linear component of the non-linear density field significantly improves the estimate of the cosmic flow in comparison to linear theory not only in the low density, but also and more dramatically in the high-density regions. In particular we test two estimates of the linear component: the lognormal model and the iterative Lagrangian linearization. The present approach relies on a rigorous higher order Lagrangian perturbation theory analysis which incorporates a non-local relation. It does not require additional fitting from simulations being in this sense parameter free, it is independent of statistical-geometrical optimization and it is straightforward and efficient to compute. The method is demonstrated to yield an unbiased estimator of the velocity field on scales ≳5 h-1 Mpc with closely Gaussian distributed errors. Moreover, the statistics of the divergence of the peculiar velocity field is extremely well recovered showing a good agreement with the true one from N-body simulations. The typical errors of about 10 km s-1 (1σ confidence intervals) are reduced by more than 80 per cent with respect to linear theory in the scale range between 5 and 10 h-1 Mpc in high-density regions (δ > 2). We also find that iterative Lagrangian linearization is significantly superior in the low-density regime with respect to the lognormal model.

The Effects of Various Ions on Resting and Spike Potentials of Barnacle Muscle Fibers

PubMed Central

Hagiwara, Susumu; Chichibu, Shiko; Naka, Ken-ichi

1964-01-01

Effects of monovalent cations and some anions on the electrical properties of the barnacle muscle fiber membrane were studied when the intra- or extracellular concentrations of those ions were altered by longitudinal intra-cellular injection. The resting potential of the normal fiber decreases linearly with increase of logarithm of [K+]out and the decrement for a tenfold increase in [K+]out is 58 mv when the product, [K+]out ·[Cl-]out, is kept constant. It also decreases with decreasing [K+]in but is always less than expected theoretically. The deviation becomes larger as [K+]in increases and the resting potential finally starts to decrease with increasing [K+]in for [K+]in > 250 mM. When the internal K+ concentration is decreased the overshoot of the spike potential increases and the time course of the spike potential becomes more prolonged. In substituting for the internal K+, Na+ and sucrose affect the resting and spike potentials similarly. Some organic cations (guanidine, choline, tris, and TMA) behave like sucrose while some other organic cations (TEA, TPA, and TBA) have a specific effect and prolong the spike potential if they are applied intracellularly or extracellularly. In all cases the active membrane potential increases linearly with the logarithm of [Ca++]out/[K+]in and the increment is about 29 mv for tenfold increase in this ratio. The fiber membrane is permeable to Cl- and other smaller anions (Br- and I-) but not to acetate- and larger anions (citrate-, sulfate-, and methanesulfonate-). PMID:14212147

Short-term cross-sensitizion of need-free sugar intake by combining sodium depletion and hypertonic NaCl intake.

PubMed

Santos, Bruna M; de Andrade, Carina A F; Menani, José V; De Luca, Laurival A

2016-12-01

History of sodium depletion cross-sensitizes the effects of drugs of abuse. The objective of the present study was to find out if history of sodium depletion also cross-sensitizes a natural reward such as sugar intake in the rat. Sodium depletion was induced by furosemide combined with removal of ambient sodium for 24 h; it was repeated seven days later. The depletion was immediately followed by 0.3 M NaCl intake in a sodium appetite test (active sodium repletion). Seven days after the last depletion, hydrated and fed (need-free) sucrose-naïve animals were offered 10% sucrose in a first 2-h sucrose test. The sucrose test was repeated once a day in a series of five consecutive days. History of sodium depletion enhanced sucrose intake in the first and second tests; it had no effect from the third to fifth sucrose test. The effect on the initial sucrose intake tests disappeared if the rats did not ingest 0.3 M NaCl in the sodium appetite test. Prior experience with sucrose intake in need-free conditions had no effect on sodium appetite. History of intracellular dehydration transiently influenced sucrose intake in the first sucrose test. We found no evidence for thirst sensitization. We conclude that history of dehydration, particularly that resulting from sodium depletion, combined to active sodium repletion, produced short-term cross-sensitization of sucrose intake in sucrose-naïve rats. The results suggest that the cross-sensitization of sucrose intake related with acquisition of sugar as a novel nutrient rather than production of lasting effects on sugar rewarding properties. Copyright © 2016 Elsevier Ltd. All rights reserved.

Sugars in Mediterranean floral nectars: an ecological and evolutionary approach.

PubMed

Petanidou, Theodora

2005-05-01

High-pressure liquid chromatography analyses of 73 plant species showed that the nectars of phrygana (East Mediterranean garrigue) mainly contain sucrose, glucose, and fructose, and traces of 10 minor sugars. Although the sucrose/hexose ratio was not related to plant life habit, ecological constraints had a detectable effect in shaping sugar composition. This was detected by distinguishing the phryganic plant species into "spring-summer" and "winter" flowering, with the distinction made on the basis of the water deficit in the study area. Plants flowering in spring-summer had a higher rate of "high sucrose" (i.e., sucrose/hexose ratio > or = 0.5; 60.8% of the plant species) vs. "low hexose" nectars (i.e., ratio <0.5; 39.2%). The ratio was reversed in winter flowering species (36.4% vs. 63.6% with "high sucrose" and "high hexose," respectively). Sucrose/hexose ratios were associated with plant family. The highest values were those of Lamiaceae, which differed significantly from the "low sucrose" Liliaceae and Apiaceae. Based on recorded plant-pollinator interactions in the community, the present data provide evidence of a partitioning of nectar resources by the existing pollinator guilds within the community, based on the sugar profiles of nectar (all sucrose/hexose ratios for all interactions). Among all major groups, bees and wasps (aculeates) preferred "high sucrose" nectars, which differed significantly from syrphids, anthomyid a.o. flies, and beetles that visited "low sucrose" nectars. Similarly, butterflies visited "lower sucrose" nectars compared to bees. Within families, only Megachilidae could be clearly characterized as "high sucrose" consumers, differing in this respect from all the remaining insect groups including most other bee families. This confirms previous findings that Megachilidae have a key position in Mediterranean communities where they probably constitute a selective factor for "high sucrose" nectars.

Evaluation of the risk of fungal spoilage when substituting sucrose with commercial purified Stevia glycosides in sweetened bakery products.

PubMed

Rodríguez, Alicia; Magan, Naresh; Medina, Angel

2016-08-16

The objectives of this study were to compare the effect of different Stevia-based sugar substitutes (S1-S3), sucrose alone and a mixture of sucrose+S1 on: (a) humectant properties, (b) relative colonisation rates of sponge cake slices at 0.90 aw by strains of Aspergillus flavus, Eurotium amstelodami, Fusarium graminearum and Penicillium verrucosum at 20 and 25°C and (c) shelf-life periods in days prior to visible growth. Results showed that sucrose, S1 commercial sugar substitute and the mixture of sucrose+S1 in water solutions were able to reach water activity levels similar to those of glycerol and glucose mixtures. The S2 and S3 commercial sugar substitutes were unable to reduce aw levels significantly. At 25°C, colonisation of sponge cake slices by E. amstelodami, A. flavus and P. verrucosum occurred in all the treatments. Growth of F. graminearum only occurred on sponge cake slices containing S2 and S3 Stevia-based products at both temperatures. The best control of growth (30days) was achieved in cake slices modified with sucrose or S1 Stevia treatments inoculated with A. flavus and in the sucrose treatment for E. amstelodami at 20°C. F. graminearum growth was completely inhibited when sucrose alone, S1 or sucrose+S1 treatments were used at both temperatures. This study suggests that, as part of a hurdle technology approach, replacing sucrose with low calorie sugar substitutes based on Stevia glycosides needs to be done with care. This is because different products may have variable humectant properties and bulking agents which may shorten the potential shelf-life of intermediate moisture bakery products. Copyright © 2016 Elsevier B.V. All rights reserved.

Expression of exo-inulinase gene from Aspergillus niger 12 in E. coli strain Rosetta-gami B (DE3) and its characterization.

PubMed

Yedahalli, Shreyas S; Rehmann, Lars; Bassi, Amarjeet

2016-05-01

Inulin is a linear carbohydrate polymer of fructose subunits (2-60) with terminal glucose units, produced as carbon storage in selected plants. It cannot directly be taken up by most microorganisms due to its large size, unless prior hydrolysis through inulinase enzymes occurs. The hydrolyzed inulin can be taken up by microbes and/or recovered and used industrially for the production of high fructose syrup, inulo-oligosaccharides, biofuel, and nutraceuticals. Cell-free enzymatic hydrolysis would be desirable for industrial applications, hence the recombinant expression, purification and characterization of an Aspergillus niger derived exo-inulinase was investigated in this study. The eukaroyototic exo-inulinase of Aspergillus niger 12 has been expressed, for the first time, in an E. coli strain [Rosetta-gami B (DE3)]. The molecular weight of recombinant exo-inulinase was estimated to be ∼81 kDa. The values of Km and Vmax of the recombinant exo-inulinase toward inulin were 5.3 ± 1.1 mM and 402.1 ± 53.1 µmol min(-1)  mg(-1) protein, respectively. Towards sucrose the corresponding values were 12.20 ± 1.6 mM and 902.8 ± 40.2 µmol min(-1)  mg(-1) protein towards sucrose. The S/I ratio was 2.24 ± 0.7, which is in the range of native inulinase. The optimum temperature and pH of the recombinant exo-inulinase towards inulin was 55°C and 5.0, while they were 50°C and 5.5 towards sucrose. The recombinant exo-inulinase activity towards inulin was enhanced by Cu(2+) and reduced by Fe(2+) , while its activity towards sucrose was enhanced by Co(2+) and reduced by Zn(2+) . © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 32:629-637, 2016. © 2016 American Institute of Chemical Engineers.

Accumulation of Amyloid β-Protein in the Low-Density Membrane Domain Accurately Reflects the Extent of β-Amyloid Deposition in the Brain

PubMed Central

Oshima, Noriko; Morishima-Kawashima, Maho; Yamaguchi, Haruyasu; Yoshimura, Masahiro; Sugihara, Shiro; Khan, Karen; Games, Dora; Schenk, Dale; Ihara, Yasuo

2001-01-01

To learn more about the process of amyloid β-protein (Aβ) deposition in the brain, human prefrontal cortices were fractionated by sucrose density gradient centrifugation, and the Aβ content in each fraction was quantified by a two-site enzyme-linked immunosorbent assay. The fractionation protocol revealed two pools of insoluble Aβ. One corresponded to a low-density membrane domain; the other was primarily composed of extracellular Aβ deposits in those cases in which Aβ accumulated to significant levels. Aβ42 levels in the low-density membrane domain were proportional to the extent of total Aβ42 accumulation, which is known to correlate well with overall amyloid burden. In PDAPP mice that form senile plaques and accumulate Aβ in a similar manner to aging humans, Aβ42 accumulation in the low-density membrane domain also increased as Aβ deposition progressed with aging. These observations indicate that the Aβ42 associated with low-density membrane domains is tightly coupled with the process of extracellular Aβ deposition. PMID:11395399

Alterations of sucrose preference after Roux-en-Y gastric bypass.

PubMed

Bueter, M; Miras, A D; Chichger, H; Fenske, W; Ghatei, M A; Bloom, S R; Unwin, R J; Lutz, T A; Spector, A C; le Roux, C W

2011-10-24

Roux-en-Y gastric bypass (gastric bypass) patients reportedly have changes in perception and consumption of sweet-tasting foods. This study aimed to further investigate alterations in sweet food intake in rats and sucrose detection in humans after gastric bypass. Wistar rats were randomized to gastric bypass or sham-operations and preference for sucrose (sweet), sodium chloride (salty), citric acid (sour) and quinine hydrochloride (bitter) was assessed with standard two-bottle intake tests (vs. water). Intestinal T1R2 and T1R3 expression and plasma levels of glucagon-like-peptide 1 (GLP-1) and peptide YY (PYY) were measured. Furthermore, obese patients and normal weight controls were tested for sucrose taste detection thresholds pre- and postoperatively. Visual analogue scales measuring hedonic perception were used to determine the sucrose concentration considered by patients and controls as "just about right" pre- and postoperatively. Gastric bypass reduced the sucrose intake relative to water in rats (p<0.001). Preoperative sucrose exposure reduced this effect. Preference or aversion for compounds representative of other taste qualities in naïve rats remained unaffected. Intestinal T1R2 and T1R3 expression was significantly decreased in the alimentary limb while plasma levels of GLP-1 and PYY were elevated after bypass in rats (p=0.01). Bypass patients showed increased taste sensitivity to low sucrose concentrations compared with controls (p<0.05), but both groups considered the same sucrose concentration as "just about right" postoperatively. In conclusion, gastric bypass reduces sucrose intake relative to water in sucrose-naïve rats, but preoperative sucrose experience attenuates this effect. Changes in sucrose taste detection do not predict hedonic taste ratings of sucrose in bypass patients which remain unchanged. Thus, factors other than the unconditional affective value of the taste may also play a role in determining food preferences after gastric bypass. Copyright © 2011 Elsevier Inc. All rights reserved.

Characterisation of a sucrose-independent in vitro biofilm model of supragingival plaque.

PubMed

Tsutsumi, K; Maruyama, M; Uchiyama, A; Shibasaki, K

2018-04-01

Sugar consumption has been decreasing in Japan, suggesting higher rates of sucrose-independent supragingival plaque formation. For developing an in vitro biofilm model of sucrose-independent supragingival plaque, this study aimed to investigate the compositions and functions on contributing to cariogenicity in comparison with sucrose-dependent biofilm. An in vitro multispecies biofilm containing Actinomyces naeslundii, Streptococcus gordonii, S. mutans, Veillonella parvula and Fusobacterium nucleatum was formed on 24-well plates in the absence or presence of 1% sucrose. Compositions were assessed by plate culture, scanning electron microscopy and confocal laser scanning microscopy after fluorescent in situ hybridisation or labelling of extracellular polymeric substances (EPS). Functions were assessed by acidogenicity, adherence strength and sensitivities to anticaries agents. Although both biofilms exhibited a Streptococcus predominant bacterial composition, there were differences in bacterial and EPS compositions; in particular, little glucan EPS was observed in sucrose-independent biofilm. Compared with sucrose-dependent biofilm, acidogenicity, adherence strength and antimicrobial resistance of sucrose-independent biofilm were only slightly lower. However, dextranase degradation was substantially lower in sucrose-independent biofilm. Our findings suggest that sucrose-independent biofilm may have cariogenicity as with sucrose-dependent biofilm. These in vitro models can help further elucidate plaque-induced caries aetiology and develop new anticaries agents. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd. All rights reserved.

Pontine and Thalamic Influences on Fluid Rewards: I. Operant Responding for Sucrose and Corn Oil

PubMed Central

Liang, Nu-Chu; Freet, Christopher S.; Grigson, Patricia S; Norgren, Ralph

2011-01-01

The reward strength of orosensory sucrose and corn oil was measured using fixed and progressive ratio operant schedules. Because the orosensory effects of the stimuli were of interest, Experiment 1 compared operant responses for sucrose in sham and real feeding rats. The results demonstrated that rats would work for sucrose solutions without the accompanying postingestive effects. Furthermore, the break points for high concentrations of sucrose (1.0 M or 2.0 M) were significantly higher in sham feeding rats than in real feeding controls. Experiment 2 investigated the role of the parabrachial nucleus (PBN) and of the thalamic orosensory area (TOA) in sucrose and corn oil reward. During free access, rats with PBN lesions (PBNx) licked significantly less sucrose solution than their controls, but both groups ingested a similar volume of corn oil emulsion. When an operant was imposed, these same PBNx rats failed to respond for sucrose and continued only modestly for corn oil. In contrast, the TOA lesioned rats (TOAx) showed no impairment in responding for sucrose or corn oil during either the free access or operant sessions. Furthermore, rats with TOA lesions demonstrated significantly higher break points for sucrose than did their controls. Together, the data imply that the PBN but not the TOA is critical for the perception of, or responding to the reward value of sucrose and corn oil. PMID:21703290

The genes and enzymes of sucrose metabolism in moderately thermophilic methanotroph Methylocaldum szegediense O12.

PubMed

But, Sergey Y; Solntseva, Natalia P; Egorova, Svetlana V; Mustakhimov, Ildar I; Khmelenina, Valentina N; Reshetnikov, Alexander; Trotsenko, Yuri A

2018-05-01

Four enzymes involved in sucrose metabolism: sucrose phosphate synthase (Sps), sucrose phosphate phosphatase (Spp), sucrose synthase (Sus) and fructokinase (FruK), were obtained as his-tagged proteins from the moderately thermophilic methanotroph Methylocaldum szegediense O12. Sps, Spp, FruK and Sus demonstrated biochemical properties similar to those of other bacterial counterparts, but the translated amino acid sequences of Sps and Spp displayed high divergence from the respective microbial enzymes. The Sus of M. szegediense O12 catalyzed the reversible reaction of sucrose cleavage in the presence of ADP or UDP and preferred ADP as a substrate, thus implying a connection between sucrose and glycogen metabolism. Sus-like genes were found only in a few methanotrophs, whereas amylosucrase was generally used in sucrose cleavage in this group of bacteria. Like other microbial fructokinases, FruK of M. szegediense O12 showed a high specificity to fructose.

Can sucrose cleavage enzymes serve as markers for sink strength and is sucrose a signal molecule during plant sink development?

Treesearch

C.C. Black; T. Lobodia; J.-Q Chen; Shi-Jean S. Sung

1995-01-01

Sucrose cleavage is an essential reaction for higher plant cells to initiate intermediary metabolism and to direct its carbon into the host of essential compounds derived therefrom for maintaining the cells of intact plants.This review will focus on: the concentrations of sucrose available to plant cells; some biochemical traits of sucrose cleavage enzymes; the...

Carbohydrate and protein intake and risk of ulcerative colitis: Systematic review and dose-response meta-analysis of epidemiological studies.

PubMed

Wang, Fan; Feng, Juerong; Gao, Qian; Ma, Minxing; Lin, Xue; Liu, Jing; Li, Jin; Zhao, Qiu

2017-10-01

Dietary carbohydrate and protein intake is generally thought as risk factors for onset of ulcerative colitis (UC), while epidemiological data had been controversial. This study aimed to evaluate the role of carbohydrate and protein intake in the development of UC. Comprehensive search in PubMed and Embase was conducted to identify all relevant studies, and the role of carbohydrate and protein intake in the development of UC was quantitatively assessed by dose-response meta-analysis. Nine studies (5 case-control and 4 prospective cohort) were identified with a total of 975 UC cases and 239352 controls. The summary relative risks (RR) for per 10 g increment/day were 1.005 (95%CI: 0.991-1.019, I 2  = 31.5%, n = 5) for total carbohydrate intake, 1.001 (95%CI: 0.971-1.032, I 2  = 0.0%, n = 7) for the subtype of fiber intake, 1.029 (95%CI: 0.962-1.101, I 2  = 68.9%, n = 2) for the subtype of sugar intake, and 1.010 (95%CI: 0.975-1.047, I 2  = 12.4%, n = 7) for total protein intake. Among sugar subtypes, only sucrose intake was found positively related with UC risk (RR for per 10 g increment/day: 1.098, 95%CI: 1.024-1.177, I 2  = 0.0%, n = 3). No evidence of a non-linear dose-response association was found between the nutrient intake and UC risk, except for the subtype of sucrose (P for non-linear trend = 0.032). Subgroup analyses showed consistent results. This meta-analysis suggested a lack of association between dietary carbohydrate or protein intake and the risk of UC, except for the subtype of sucrose which played a significant role in the development of UC. Large-scale prospective designed studies are needed to confirm our findings. Copyright © 2016 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.

The sucrose-trehalose 6-phosphate (Tre6P) nexus: specificity and mechanisms of sucrose signalling by Tre6P.

PubMed

Yadav, Umesh Prasad; Ivakov, Alexander; Feil, Regina; Duan, Guang You; Walther, Dirk; Giavalisco, Patrick; Piques, Maria; Carillo, Petronia; Hubberten, Hans-Michael; Stitt, Mark; Lunn, John Edward

2014-03-01

Trehalose 6-phosphate (Tre6P), the intermediate of trehalose biosynthesis, has a profound influence on plant metabolism, growth, and development. It has been proposed that Tre6P acts as a signal of sugar availability and is possibly specific for sucrose status. Short-term sugar-feeding experiments were carried out with carbon-starved Arabidopsis thaliana seedlings grown in axenic shaking liquid cultures. Tre6P increased when seedlings were exogenously supplied with sucrose, or with hexoses that can be metabolized to sucrose, such as glucose and fructose. Conditional correlation analysis and inhibitor experiments indicated that the hexose-induced increase in Tre6P was an indirect response dependent on conversion of the hexose sugars to sucrose. Tre6P content was affected by changes in nitrogen status, but this response was also attributable to parallel changes in sucrose. The sucrose-induced rise in Tre6P was unaffected by cordycepin but almost completely blocked by cycloheximide, indicating that de novo protein synthesis is necessary for the response. There was a strong correlation between Tre6P and sucrose even in lines that constitutively express heterologous trehalose-phosphate synthase or trehalose-phosphate phosphatase, although the Tre6P:sucrose ratio was shifted higher or lower, respectively. It is proposed that the Tre6P:sucrose ratio is a critical parameter for the plant and forms part of a homeostatic mechanism to maintain sucrose levels within a range that is appropriate for the cell type and developmental stage of the plant.

Down-regulation of the sucrose transporters HvSUT1 and HvSUT2 affects sucrose homeostasis along its delivery path in barley grains.

PubMed

Radchuk, Volodymyr; Riewe, David; Peukert, Manuela; Matros, Andrea; Strickert, Marc; Radchuk, Ruslana; Weier, Diana; Steinbiß, Hans-Henning; Sreenivasulu, Nese; Weschke, Winfriede; Weber, Hans

2017-07-20

Sucrose transport and partitioning are crucial for seed filling. While many plasma-membrane-localised sucrose transporters (SUT1 family members) have been analysed in seeds, the functions of vacuolar SUT2 members are still obscure. In barley grains, expression of HvSUT1 and HvSUT2 overlap temporally and spatially, suggesting concerted functions to regulate sucrose homeostasis. Using HvSUT2-RNAi plants, we found that grains were also deficient in HvSUT1 expression and seemingly sucrose-limited during mid-to-late grain filling. Transgenic endosperms accumulated less starch and dry weight, although overall sucrose and hexose contents were higher. Comprehensive transcript and metabolite profiling revealed that genes related to glycolysis, the tricarboxylic acid cycle, starch and amino acid synthesis, grain maturation, and abscisic acid signalling were down-regulated together with most glycolytic intermediates and amino acids. Sucrose was increased along the sucrose delivery route in the nucellar projection, the endosperm transfer cells, and the starchy endosperm, indicating that suppressed transporter activity diminished sucrose efflux from vacuoles, which generated sugar deficiency in the cytoplasm. Thus, endosperm vacuoles may buffer sucrose concentrations to regulate homeostasis at grain filling. Transcriptional changes revealed that limited endosperm sucrose initiated sugar starvation responses, such as sugar recycling from starch, hemicelluloses and celluloses together with vacuolar protein degradation, thereby supporting formation of nucleotide sugars. Barley endosperm cells can thus suppress certain pathways to retrieve resources to maintain essential cell functions. © The Author 2017. Published by Oxford University Press on behalf of the Society for Experimental Biology.

Identification and classification of genes required for tolerance to high-sucrose stress revealed by genome-wide screening of Saccharomyces cerevisiae.

PubMed

Ando, Akira; Tanaka, Fumiko; Murata, Yoshinori; Takagi, Hiroshi; Shima, Jun

2006-03-01

Yeasts used in bread making are exposed to high concentrations of sucrose during sweet dough fermentation. Despite its importance, tolerance to high-sucrose stress is poorly understood at the gene level. To clarify the genes required for tolerance to high-sucrose stress, genome-wide screening was undertaken using the complete deletion strain collection of diploid Saccharomyces cerevisiae. The screening identified 273 deletions that yielded high sucrose sensitivity, approximately 20 of which were previously uncharacterized. These 273 deleted genes were classified based on their cellular function and localization of their gene products. Cross-sensitivity of the high-sucrose-sensitive mutants to high concentrations of NaCl and sorbitol was studied. Among the 273 sucrose-sensitive deletion mutants, 269 showed cross-sensitivities to sorbitol or NaCl, and four (i.e. ade5,7, ade6, ade8, and pde2) were specifically sensitive to high sucrose. The general stress response pathways via high-osmolarity glycerol and stress response element pathways and the function of the invertase in the ade mutants were similar to those in the wild-type strain. In the presence of high-sucrose stress, intracellular contents of ATP in ade mutants were at least twofold lower than that of the wild-type cells, suggesting that depletion of ATP is a factor in sensitivity to high-sucrose stress. The genes identified in this study might be important for tolerance to high-sucrose stress, and therefore should be target genes in future research into molecular modification for breeding of yeast tolerant to high-sucrose stress.

Tonoplast Sugar Transporters (SbTSTs) putatively control sucrose accumulation in sweet sorghum stems.

PubMed

Bihmidine, Saadia; Julius, Benjamin T; Dweikat, Ismail; Braun, David M

2016-01-01

Carbohydrates are differentially partitioned in sweet versus grain sorghums. While the latter preferentially accumulate starch in the grain, the former primarily store large amounts of sucrose in the stem. Previous work determined that neither sucrose metabolizing enzymes nor changes in Sucrose transporter (SUT) gene expression accounted for the carbohydrate partitioning differences. Recently, 2 additional classes of sucrose transport proteins, Tonoplast Sugar Transporters (TSTs) and SWEETs, were identified; thus, we examined whether their expression tracked sucrose accumulation in sweet sorghum stems. We determined 2 TSTs were differentially expressed in sweet vs. grain sorghum stems, likely underlying the massive difference in sucrose accumulation. A model illustrating potential roles for different classes of sugar transport proteins in sorghum sugar partitioning is discussed.

CLC-Nt1, a putative chloride channel protein of tobacco, co-localizes with mitochondrial membrane markers.

PubMed Central

Lurin, C; Güclü, J; Cheniclet, C; Carde, J P; Barbier-Brygoo, H; Maurel, C

2000-01-01

The voltage-dependent chloride channel (CLC) family of membrane proteins has cognates in animals, yeast, bacteria and plants, and chloride-channel activity has been assigned to most of the animal homologues. Lack of evidence of CLC functions in plants prompted us to characterize the cellular localization of the tobacco CLC-Nt1 protein. Specific polyclonal antibodies were raised against an N-terminal polypeptide of CLC-Nt1. These antibodies were used to probe membrane proteins prepared by various cell-fractionation methods. These included aqueous two-phase partitioning (for plasma membranes), free-flow electrophoresis (for vacuolar and plasma membranes), intact vacuole isolation, Percoll-gradient centrifugation (for plastids and mitochondria) and stepped, linear, sucrose-density-gradient centrifugation (for mitochondria). Each purified membrane fraction was characterized with specific marker enzyme activities or antibodies. Our studies ruled out the possibility that the major cell localization of CLC-Nt1 was the vacuolar or plasma membranes, the endoplasmic reticulum, the Golgi apparatus or the plastids. In contrast, we showed that the tobacco CLC-Nt1 specifically co-localized with the markers of the mitochondrial inner membrane, cytochrome c oxidase and NAD9 protein. CLC-Nt1 may correspond to the inner membrane anion channel ('IMAC') described previously in animal and plant mitochondria. PMID:10816421

CLC-Nt1, a putative chloride channel protein of tobacco, co-localizes with mitochondrial membrane markers.

PubMed

Lurin, C; Güclü, J; Cheniclet, C; Carde, J P; Barbier-Brygoo, H; Maurel, C

2000-06-01

The voltage-dependent chloride channel (CLC) family of membrane proteins has cognates in animals, yeast, bacteria and plants, and chloride-channel activity has been assigned to most of the animal homologues. Lack of evidence of CLC functions in plants prompted us to characterize the cellular localization of the tobacco CLC-Nt1 protein. Specific polyclonal antibodies were raised against an N-terminal polypeptide of CLC-Nt1. These antibodies were used to probe membrane proteins prepared by various cell-fractionation methods. These included aqueous two-phase partitioning (for plasma membranes), free-flow electrophoresis (for vacuolar and plasma membranes), intact vacuole isolation, Percoll-gradient centrifugation (for plastids and mitochondria) and stepped, linear, sucrose-density-gradient centrifugation (for mitochondria). Each purified membrane fraction was characterized with specific marker enzyme activities or antibodies. Our studies ruled out the possibility that the major cell localization of CLC-Nt1 was the vacuolar or plasma membranes, the endoplasmic reticulum, the Golgi apparatus or the plastids. In contrast, we showed that the tobacco CLC-Nt1 specifically co-localized with the markers of the mitochondrial inner membrane, cytochrome c oxidase and NAD9 protein. CLC-Nt1 may correspond to the inner membrane anion channel ('IMAC') described previously in animal and plant mitochondria.

PHOTOMETRIC EVIDENCE FOR THE OSMOTIC BEHAVIOR OF RAT LIVER MICROSOMES

PubMed Central

Tedeschi, Henry; James, Joseph M.; Anthony, William

1963-01-01

Electron microscope observations are consistent with the interpretation that the elements of the endoplasmic reticulum are osmotically active in situ as well as after isolation. More recently, it has been reported that microsomal suspensions equilibrate almost completely with added C14-sucrose and that no osmotic behavior is evident from photometric data. These findings were considered at variance with the electron microscope data. However, equilibration with added label simply attests to a relatively high permeability, and, in addition, the photometric data need not be critical. Osmotic volume changes, measured photometrically, may be masked by concomitant events (e.g., changes in the refractive index of the test solutions at varying osmotic pressures, breakdown of the particles, and agglutination). For these reasons the photometric experiments were repeated. In this work, the reciprocal of optical density of microsomal suspensions was found to vary linearly with the reciprocal of concentration of the medium at constant refractive index. These changes probably correspond to osmotic volume changes, since the effect was found to be (a) independent of substance used and (b) osmotically reversible. The transmission of the suspension was found to vary with the refractive index of the medium, the concentration of particles, and the wavelength of incident light, according to relationships that are similar to or identical with those obtained for mitochondrial suspensions. PMID:14064105

Sucrose accumulation in sweet sorghum stems occurs by apoplasmic phloem unloading and does not involve differential Sucrose transporter expression

DOE PAGES

Bihmidine, Saadia; Baker, R. Frank; Hoffner, Cassandra; ...

2015-07-30

Background: Sorghum (Sorghum bicolor L. Moench) cultivars store non-structural carbohydrates predominantly as either starch in seeds (grain sorghums) or sugars in stems (sweet sorghums). Previous research determined that sucrose accumulation in sweet sorghum stems was not correlated with the activities of enzymes functioning in sucrose metabolism, and that an apoplasmic transport step may be involved in stem sucrose accumulation. However, the sucrose unloading pathway from stem phloem to storage parenchyma cells remains unelucidated. Sucrose transporters (SUTs) transport sucrose across membranes, and have been proposed to function in sucrose partitioning differences between sweet and grain sorghums. The purpose of this studymore » was to characterize the key differences in carbohydrate accumulation between a sweet and a grain sorghum, to define the path sucrose may follow for accumulation in sorghum stems, and to determine the roles played by sorghum SUTs in stem sucrose accumulation. Results: Dye tracer studies to determine the sucrose transport route revealed that, for both the sweet sorghum cultivar Wray and grain sorghum cultivar Macia, the phloem in the stem veins was symplasmically isolated from surrounding cells, suggesting sucrose was apoplasmically unloaded. Once in the phloem apoplasm, a soluble tracer diffused from the vein to stem parenchyma cell walls, indicating the lignified mestome sheath encompassing the vein did not prevent apoplasmic flux outside of the vein. To characterize carbohydrate partitioning differences between Wray and Macia, we compared the growth, stem juice volume, solute contents, SbSUTs gene expression, and additional traits. Contrary to previous findings, we detected no significant differences in SbSUTs gene expression within stem tissues. Conclusions: Phloem sieve tubes within sweet and grain sorghum stems are symplasmically isolated from surrounding cells; hence, unloading from the phloem likely occurs apoplasmically, thereby defining the location of the previously postulated step for sucrose transport. Additionally, no changes in SbSUTs gene expression were detected in sweet vs. grain sorghum stems, suggesting alterations in SbSUT transcript levels do not account for the carbohydrate partitioning differences between cultivars. A model illustrating sucrose phloem unloading and movement to stem storage parenchyma, and highlighting roles for sucrose transport proteins in sorghum stems is discussed.« less

Sugar-mediated acclimation: the importance of sucrose metabolism in meristems.

PubMed

Carpentier, Sebastien Christian; Vertommen, Annelies; Swennen, Rony; Witters, Erwin; Fortes, Claudia; Souza, Manoel T; Panis, Bart

2010-10-01

We have designed an in vitro experimental setup to study the role of sucrose in sugar-mediated acclimation of banana meristems using established highly proliferating meristem cultures. It is a first step toward the systems biology of a meristem and the understanding of how it can survive severe abiotic stress. Using the 2D-DIGE proteomic approach and a meristem-specific EST library, we describe the long-term acclimation response of banana meristems (after 2, 4, 8, and 14 days) and analyze the role of sucrose in this acclimation by setting up a control, a sorbitol, and a sucrose acclimation treatment over time. Sucrose synthase is the dominant enzyme for sucrose breakdown in meristem tissue, which is most likely related to its lower energy consumption. Metabolizing sucrose is of paramount importance to survive, but the uptake of sugar and its metabolism also drive respiration, which may result in limited oxygen levels. According to our data, a successful acclimation is correlated to an initial efficient uptake of sucrose and subsequently a reduced breakdown of sucrose and an induction of fermentation likely by a lack of oxygen.

Rerouting Carbon Flux To Enhance Photosynthetic Productivity

PubMed Central

Ducat, Daniel C.; Avelar-Rivas, J. Abraham; Way, Jeffrey C.

2012-01-01

The bioindustrial production of fuels, chemicals, and therapeutics typically relies upon carbohydrate inputs derived from agricultural plants, resulting in the entanglement of food and chemical commodity markets. We demonstrate the efficient production of sucrose from a cyanobacterial species, Synechococcus elongatus, heterologously expressing a symporter of protons and sucrose (cscB). cscB-expressing cyanobacteria export sucrose irreversibly to concentrations of >10 mM without culture toxicity. Moreover, sucrose-exporting cyanobacteria exhibit increased biomass production rates relative to wild-type strains, accompanied by enhanced photosystem II activity, carbon fixation, and chlorophyll content. The genetic modification of sucrose biosynthesis pathways to minimize competing glucose- or sucrose-consuming reactions can further improve sucrose production, allowing the export of sucrose at rates of up to 36.1 mg liter−1 h illumination−1. This rate of production exceeds that of previous reports of targeted, photobiological production from microbes. Engineered S. elongatus produces sucrose in sufficient quantities (up to ∼80% of total biomass) such that it may be a viable alternative to sugar synthesis from terrestrial plants, including sugarcane. PMID:22307292

Molecular motions in sucrose-PVP and sucrose-sorbitol dispersions-II. Implications of annealing on secondary relaxations.

PubMed

Bhattacharya, Sisir; Bhardwaj, Sunny P; Suryanarayanan, Raj

2014-10-01

To determine the effect of annealing on the two secondary relaxations in amorphous sucrose and in sucrose solid dispersions. Sucrose was co-lyophilized with either PVP or sorbitol, annealed for different time periods and analyzed by dielectric spectroscopy. In an earlier investigation, we had documented the effect of PVP and sorbitol on the primary and the two secondary relaxations in amorphous sucrose solid dispersions (1). Here we investigated the effect of annealing on local motions, both in amorphous sucrose and in the dispersions. The average relaxation time of the local motion (irrespective of origin) in sucrose, decreased upon annealing. However, the heterogeneity in relaxation time distribution as well as the dielectric strength decreased only for β1- (the slower relaxation) but not for β2-relaxations. The effect of annealing on β2-relaxation times was neutralized by sorbitol while PVP negated the effect of annealing on both β1- and β2-relaxations. An increase in local mobility of sucrose brought about by annealing could be negated with an additive.

Rerouting Carbon Flux To Enhance Photosynthetic Productivity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ducat, DC; Avelar-Rivas, JA; Way, JC

2012-03-23

The bioindustrial production of fuels, chemicals, and therapeutics typically relies upon carbohydrate inputs derived from agricultural plants, resulting in the entanglement of food and chemical commodity markets. We demonstrate the efficient production of sucrose from a cyanobacterial species, Synechococcus elongatus, heterologously expressing a symporter of protons and sucrose (cscB). cscB-expressing cyanobacteria export sucrose irreversibly to concentrations of >10 mM without culture toxicity. Moreover, sucrose-exporting cyanobacteria exhibit increased biomass production rates relative to wild-type strains, accompanied by enhanced photosystem II activity, carbon fixation, and chlorophyll content. The genetic modification of sucrose biosynthesis pathways to minimize competing glucose-or sucrose-consuming reactions can furthermore » improve sucrose production, allowing the export of sucrose at rates of up to 36.1 mg liter(-1) h illumination(-1). This rate of production exceeds that of previous reports of targeted, photobiological production from microbes. Engineered S. elongatus produces sucrose in sufficient quantities (up to similar to 80% of total biomass) such that it may be a viable alternative to sugar synthesis from terrestrial plants, including sugarcane.« less

High-efficiency acceleration in the laser wakefield by a linearly increasing plasma density

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dong, Kegong; Wu, Yuchi; Zhu, Bin

The acceleration length and the peak energy of the electron beam are limited by the dephasing effect in the laser wakefield acceleration with uniform plasma density. Based on 2D-3V particle in cell simulations, the effects of a linearly increasing plasma density on the electron acceleration are investigated broadly. Comparing with the uniform plasma density, because of the prolongation of the acceleration length and the gradually increasing accelerating field due to the increasing plasma density, the electron beam energy is twice higher in moderate nonlinear wakefield regime. Because of the lower plasma density, the linearly increasing plasma density can also avoidmore » the dark current caused by additional injection. At the optimal acceleration length, the electron energy can be increased from 350 MeV (uniform) to 760 MeV (linearly increasing) with the energy spread of 1.8%, the beam duration is 5 fs and the beam waist is 1.25 μm. This linearly increasing plasma density distribution can be achieved by a capillary with special gas-filled structure, and is much more suitable for experiment.« less

Sucrose-enhanced biosynthesis of medicinally important antioxidant secondary metabolites in cell suspension cultures of Artemisia absinthium L.

PubMed

Ali, Mohammad; Abbasi, Bilal Haider; Ahmad, Nisar; Ali, Syed Shujait; Ali, Shahid; Ali, Gul Shad

2016-12-01

Natural products are gaining tremendous importance in pharmaceutical industry and attention has been focused on the applications of in vitro technologies to enhance yield and productivity of such products. In this study, we investigated the accumulation of biomass and antioxidant secondary metabolites in response to different carbohydrate sources (sucrose, maltose, fructose and glucose) and sucrose concentrations (1, 3, 5, 7 and 9 %). Moreover, the effects of 3 % repeated sucrose feeding (day-12, -18 and -24) were also investigated. The results showed the superiority of disaccharides over monosaccharides for maximum biomass and secondary metabolites accumulation. Comparable profiles for maximum biomass were observed in response to sucrose and maltose and initial sucrose concentrations of 3 and 5 %. Maximum total phenolic and total flavonoid contents were displayed by cultures treated with sucrose and maltose; however, initial sucrose concentrations of 5 and 7 % were optimum for both classes of metabolites, respectively. Following 3 % extra sucrose feeding, cultures fed on day-24 (late-log phase) showed higher biomass, total phenolic and total flavonoid contents as compared to control cultures. Highest antioxidant activity was exhibited by maltose-treated cultures. Moreover, sucrose-treated cultures displayed positive correlation of antioxidant activity with total phenolics and total flavonoids production. This work describes the stimulatory role of disaccharides and sucrose feeding strategy for higher accumulation of phenolics and flavonoids, which could be potentially scaled up to bioreactor level for the bulk production of these metabolites in suspension cultures of A. absinthium.

Exopolysaccharide-producing lactic acid bacteria strains from traditional Thai fermented foods: isolation, identification and exopolysaccharide characterization.

PubMed

Smitinont, T; Tansakul, C; Tanasupawat, S; Keeratipibul, S; Navarini, L; Bosco, M; Cescutti, P

1999-10-15

Lactic Acid Bacteria (LAB) isolated from various traditional Thai fermented foods were screened for exopolysaccharides (EPS) production. From 104 isolates, two rod-shaped and five coccal-shaped LAB were able to produce EPS from sucrose on solid media. However, only the cocci were capable of producing EPS in liquid media and these were identified as Pediococcus pentosaceus. Pediococcus pentosaceus strains AP-1 and AP-3 produced EPS in high yield. In liquid media containing sucrose as carbon source, the amount of EPS produced by AP-1 and AP-3 strains was 6.0 and 2.5 g/L, respectively. The isolated and purified EPSs were chemically characterized. On the basis of sugar composition, methylation analysis and nuclear magnetic resonance spectroscopy, both the EPSs were shown to belong to the same dextran class. In particular, both EPSs differed from linear dextran by branching through 3,6-di-Osubstituted alpha-D-glucopyranosyl residues. The EPS from P. pentosaceus AP-3 was characterized by a relatively higher degree of branching and by a higher molecular weight than that from P. pentosaceus AP-1.

[Simultaneous determination of sugar alcohols and sugars in functional foods by precolumn ultraviolet derivatization--high performance liquid chromatography].

PubMed

Liu, Ya-Pan; Ran, Xue-Qin; Chen, Lu-Ying; Zhang, Jing; Ruan, Jia; Li, Yong-Xin; Sun, Chengjun

2014-09-01

To establish a method using precolumn ultraviolet derivatization coupled with high performance liquid chromatography (HPLC) for simultaneous determination of erythritol, xylitol, galactitol, sorbitol, mannitol, maltitol, glucose and sucrose in functional foods. Target sugar alcohols and sugars in food samples were extracted in water by ultrasonic method and then reacted with benzoyl chloride to form violet-absorbing products, which were separated on a C18 column with gradient elution using methanol and water as mobile phase. The experiment was performed using a flow rate of 1.00 mL/min, column temperature at 30 degrees C and detected wavelength at 232 nm. The linear correlation coefficients of all the derivatives were more than 0. 999. The detection limits of the method were as low as 2. 2 microg/mL. The average recoveries were 89.6%-117.0%, with intraday relative standard derivations lower than 5%. This method is simple, inexpensive and easy to operate and it is suitable for the determination of sugar alcohols and glucose and sucrose in functional foods.

Streptococcus mutans Adherence: Presumptive Evidence for Protein-Mediated Attachment Followed by Glucan-Dependent Cellular Accumulation

PubMed Central

Staat, Robert H.; Langley, Sharon D.; Doyle, R. J.

1980-01-01

Adherence of Streptococcus mutans to smooth surfaces has been attributed to the production of sucrose-derived d-glucans. However, several studies indicate that the bacterium will adhere in the absence of sucrose. The present data confirmed that S. mutans adherence to saliva-coated hydroxyapatite beads in the absence of sucrose is described by the Langmuir equation. The nature of the sucrose-independent adherence was studied with the Persea americana agglutinin as a selective adherence inhibitor. Pretreatment of the bacterium with P. americana agglutinin caused a 10-fold reduction in adherence, and the inhibition was not reversed with the addition of sucrose. Pretreatment of S. mutans with proteases also reduced adherence, regardless of the sucrose content, whereas periodate oxidation and glucanohydrolase treatment of the bacteria reduced sucrose-mediated adherence to the levels found for sucrose-independent adherence. The P. americana agglutinin, glucanohydrolase, and pepsin pretreatment of the cells did not eliminate sucrose-induced agglutination. Scanning electron microscopy showed that short streptococcal chains were bound to saliva-coated hydroxyapatite crystals in the sucrose-independent system, whereas the presence of sucrose caused larger bacterial clumps to be found. A two-reaction model of S. mutans adherence was developed from these data. It is proposed that one reaction is attachment to the tooth pellicle which is mediated by cell-surface proteins rather than glucans or teichoic acids. The other reaction is cellular accumulation mediated by sucrose-derived d-glucans and cell surface lectins. A series of sequential adherence experiments with P. americana agglutinin as a selective inhibitor provided presumptive evidence for the validity of our model of S. mutans adherence. Images Fig. 1 PMID:7380545

Opioid-receptor subtype agonist-induced enhancements of sucrose intake are dependent upon sucrose concentration.

PubMed

Ruegg, H; Yu, W Z; Bodnar, R J

1997-07-01

Selective mu ([D-Ala2, N-Me-Phe4, Gly-ol5]-enkephalin (DAMGO)), delta1 ([D-Pen2, D-Pen5]-enkephalin (DPDPE)), delta2 ([D-Ala2, Glu4]-Deltorphin (Delt II)), kappa1 (U50488H) and kappa3 (naloxone benzoylhydrazone (NalBzOH)) opioid agonists each stimulate food intake in rats. Whereas studies with selective opioid antagonists implicate mu and kappa1 receptors in the mediation of sucrose intake, studies with selective opioid agonists implicate mu and delta receptors in the mediation of saccharin intake. The present study determined if specific delta1, delta2, kappa1, kappa3 and mu opioid-receptor subtype agonists produced similar alterations in sucrose intake as a function of sucrose concentration (0.5%, 2.5%, 10%) across a 1-h time-course. Each of these agonists significantly increased sucrose intake with variations in pattern, magnitude, and consistency as a function of sucrose concentration. Whereas the mu opioid agonist, DAMGO, and the delta1 opioid agonist, DPDPE, each enhanced sucrose intake at higher (2.5%, 10%), but not lower (0.5%), concentrations, the delta2 opioid agonist, Delt II, increased sucrose intake at lower (0.5%, 2.5%), but not higher (10%), concentrations. Kappa opioid agonists produced less consistent effects. The kappa1 opioid agonist, U50488H, increased sucrose intake at high (10%) concentrations and decreased sucrose intake at low (0.5%) concentrations, and the kappa3 opioid agonist, NalBzOH, inconsistently increased sucrose intake at the 0.5% (20 microg) and 10% (1 microg) concentrations. Thus, these data further implicate mu, delta1, and delta2 opioid mediation of palatable intake, particularly of its orosensory characteristics.

A re-assessment of sucrose signaling involved in cluster-root formation and function in phosphate-deficient white lupin (Lupinus albus).

PubMed

Wang, Zhengrui; Shen, Jianbo; Ludewig, Uwe; Neumann, Günter

2015-07-01

Apart from substrate functions, a signaling role of sucrose in root growth regulation is well established. This raised the question whether sucrose signals might also be involved in formation of cluster-roots (CRs) under phosphate (Pi) limitation, mediating exudation of phosphorus (P)-mobilizing root exudates, e.g. in Lupinus albus and members of the Proteaceae. Earlier studies demonstrated that CR formation in L. albus was mimicked to some extent by external application of high sucrose concentrations (25 mM) in the presence of extremely high P supply (1-10 mM), usually suppressing CR formation. In this study, we re-addressed this question using an axenic hydroponic culture system with normal P supply (0.1 mM) and a range of sucrose applications (0.25-25 mM). The 2.5 mM sucrose concentration was comparable with internal sucrose levels in the zone of CR initiation in first-order laterals of P-deficient plants (3.4 mM) and induced the same CR morphology. Similar to earlier studies, high sucrose concentrations (25 mM) resulted in root thickening and inhibition of root elongation, associated with a 10-fold increase of the internal sucrose level. The sucrose analog palatinose and a combination of glucose/fructose failed to stimulate CR formation under P-sufficient conditions, demonstrating a signal function of sucrose and excluding osmotic or carbon source effects. In contrast to earlier findings, sucrose was able to induce CR formation but had no effect on CR functioning with respect to citrate exudation, in vitro activity and expression of genes encoding phosphoenolpyruvate carboxylase, secretory acid phosphatase and MATE transporters, mediating P-mobilizing functions of CRs. © 2014 Scandinavian Plant Physiology Society.

Effects of Soil Salinity on Sucrose Metabolism in Cotton Fiber

PubMed Central

Liu, Jingran; Luo, Junyu; Zhao, Xinhua; Dong, Helin; Ma, Yan; Sui, Ning; Zhou, Zhiguo; Meng, Yali

2016-01-01

Cotton (Gosspium hirsutum L.) is classified as a salt tolerant crop. However, its yield and fiber quality are negatively affected by soil salinity. Studies on the enzymatic differences in sucrose metabolism under different soil salinity levels are lacking. Therefore, field experiments, using two cotton cultivars, CCRI-79 (salt-tolerant) and Simian 3 (salt-sensitive), were conducted in 2013 and 2014 at three different salinity levels (1.15 dS m-1 [low soil salinity], 6.00 dS m-1 [medium soil salinity], and 11.46 dS m-1 [high soil salinity]). The objective was to elucidate the effects of soil salinity on sucrose content and the activity of key enzymes that are related to sucrose metabolism in cotton fiber. Results showed that as the soil salinity increased, cellulose content, sucrose content, and sucrose transformation rate declined; the decreases in cellulose content and sucrose transformation rate caused by the increase in soil salinity were more in Simian 3 than those in CCRI-79. With increase in soil salinity, activities of sucrose metabolism enzymes sucrose phophate synthase (SPS), acidic invertase, and alkaline invertase were decreased, whereas sucrose synthase (SuSy) activity increased. However, the changes displayed in the SuSy and SPS activities in response to increase in soil salinity were different and the differences were large between the two cotton cultivars. These results illustrated that suppressed cellulose synthesis and sucrose metabolism under high soil salinity were mainly due to the change in SPS, SuSy, and invertase activities, and the difference in cellulose synthesis and sucrose metabolism in fiber for the two cotton cultivars in response to soil salinity was determined mainly by both SuSy and SPS activities. PMID:27227773

In vitro degradation of ribosomes.

PubMed

Mora, G; Rivas, A

1976-12-01

The cytoplasmic ribosomes from Euglena gracilis var. bacillaris are found to be of two types taking into consideration their stability "in vitro". In the group of unstable ribosomes the large subunit is degraded. The other group apparently does not suffer any degradation under the conditions described. However the RNAs extracted from both types of ribosomes are degraded during sucrose density gradients. The degradation of the largest RNA species has been reported previously, but no comment has been made about the stability of the ribosome itself.

Longevity and food consumption of microwave-treated (2. 45 GHz CW) honeybees in the laboratory

DOE Office of Scientific and Technical Information (OSTI.GOV)

Westerdahl, B.B.; Gary, N.E.

1981-01-01

Adult honeybees, confined singly or in small clusters, were exposed for 0.5, 6, and 24 hours to 2.45-GHz continuous wave microwave radiation at power densities of 3, 6, 12, 25, and 50 mW/cm2. Following exposure, bees were held in the incubator for 21 days to determine the consumption of sucrose syrup and to observe mortality. No significant differences were found between microwave-treated and sham-treated or control bees.

Identification of drought-response genes and a study of their expression during sucrose accumulation and water deficit in sugarcane culms.

PubMed

Iskandar, Hayati M; Casu, Rosanne E; Fletcher, Andrew T; Schmidt, Susanne; Xu, Jingsheng; Maclean, Donald J; Manners, John M; Bonnett, Graham D

2011-01-13

The ability of sugarcane to accumulate high concentrations of sucrose in its culm requires adaptation to maintain cellular function under the high solute load. We have investigated the expression of 51 genes implicated in abiotic stress to determine their expression in the context of sucrose accumulation by studying mature and immature culm internodes of a high sucrose accumulating sugarcane cultivar. Using a sub-set of eight genes, expression was examined in mature internode tissues of sugarcane cultivars as well as ancestral and more widely related species with a range of sucrose contents. Expression of these genes was also analysed in internode tissue from a high sucrose cultivar undergoing water deficit stress to compare effects of sucrose accumulation and water deficit. A sub-set of stress-related genes that are potentially associated with sucrose accumulation in sugarcane culms was identified through correlation analysis, and these included genes encoding enzymes involved in amino acid metabolism, a sugar transporter and a transcription factor. Subsequent analysis of the expression of these stress-response genes in sugarcane plants that were under water deficit stress revealed a different transcriptional profile to that which correlated with sucrose accumulation. For example, genes with homology to late embryogenesis abundant-related proteins and dehydrin were strongly induced under water deficit but this did not correlate with sucrose content. The expression of genes encoding proline biosynthesis was associated with both sucrose accumulation and water deficit, but amino acid analysis indicated that proline was negatively correlated with sucrose concentration, and whilst total amino acid concentrations increased about seven-fold under water deficit, the relatively low concentration of proline suggested that it had no osmoprotectant role in sugarcane culms. The results show that while there was a change in stress-related gene expression associated with sucrose accumulation, different mechanisms are responding to the stress induced by water deficit, because different genes had altered expression under water deficit.

Social reinforcement as alternative to sucrose reinforcement is increased by nicotine and methylphenidate in male Fischer-344 rats.

PubMed

Martin, Connor D; Bool, Heather M; George, Anthony M; Carr, Katelyn A; Epstein, Leonard H; Hawk, Larry W; Richards, Jerry B

2018-04-24

Stimulant drugs such as nicotine (NIC) and methylphenidate (MPH) are hypothesized to increase the reinforcing value of sensory stimuli, thus increasing the effectiveness of such reinforcers as alternatives to sucrose reinforcers. Inbred Fischer-344 rats (n = 30) were assigned to three groups: saline (SAL; n = 10), nicotine (NIC; n = 10), or methylphenidate (MPH; n = 10). Testing was done in three phases: sucrose only, (SUC), sucrose and drug (SUC/DRUG), and sucrose, drug, and social reinforcement (SUC/DRUG/SOC). During the SUC phase, rats were trained on a progressive ratio 5 (PR5) reinforcement schedule for sucrose (20% solution). In the SUC/DRUG phase, animals were treated with SAL, NIC (0.4 mg/kg, n = 10 SC), or MPH (2.0 mg/kg, n = 10 IP) 30 min prior to testing. In the SUC/DRUG/SOC phase, animals continued receiving drug treatment, and social reinforcement was introduced concurrently with the sucrose reinforcer. The progressive ratio for each reinforcer ran independently of the others. Reinforcing value was measured as break point (BP), the highest number of responses resulting in a reinforcer. SAL-treated animals showed no significant change in sucrose BP. MPH-treated animals showed decreased sucrose BP in the SUC/DRUG phase, with a further reduction in the SUC/DRUG/SOC phase. NIC-treated animals decreased sucrose BP only when a social alternative was offered. Both NIC and MPH reduce the sucrose BP in the presence of a social alternative. The decrease in sucrose responding, coupled with increased social responding, suggests that the social alternative acted as an effective alternative reinforcer to sucrose. From a translational perspective, these results suggest that stimulant drugs such as NIC and MPH may increase the effectiveness of treatments that use alternative social reinforcers to decrease eating.

Identification of drought-response genes and a study of their expression during sucrose accumulation and water deficit in sugarcane culms

PubMed Central

2011-01-01

Background The ability of sugarcane to accumulate high concentrations of sucrose in its culm requires adaptation to maintain cellular function under the high solute load. We have investigated the expression of 51 genes implicated in abiotic stress to determine their expression in the context of sucrose accumulation by studying mature and immature culm internodes of a high sucrose accumulating sugarcane cultivar. Using a sub-set of eight genes, expression was examined in mature internode tissues of sugarcane cultivars as well as ancestral and more widely related species with a range of sucrose contents. Expression of these genes was also analysed in internode tissue from a high sucrose cultivar undergoing water deficit stress to compare effects of sucrose accumulation and water deficit. Results A sub-set of stress-related genes that are potentially associated with sucrose accumulation in sugarcane culms was identified through correlation analysis, and these included genes encoding enzymes involved in amino acid metabolism, a sugar transporter and a transcription factor. Subsequent analysis of the expression of these stress-response genes in sugarcane plants that were under water deficit stress revealed a different transcriptional profile to that which correlated with sucrose accumulation. For example, genes with homology to late embryogenesis abundant-related proteins and dehydrin were strongly induced under water deficit but this did not correlate with sucrose content. The expression of genes encoding proline biosynthesis was associated with both sucrose accumulation and water deficit, but amino acid analysis indicated that proline was negatively correlated with sucrose concentration, and whilst total amino acid concentrations increased about seven-fold under water deficit, the relatively low concentration of proline suggested that it had no osmoprotectant role in sugarcane culms. Conclusions The results show that while there was a change in stress-related gene expression associated with sucrose accumulation, different mechanisms are responding to the stress induced by water deficit, because different genes had altered expression under water deficit. PMID:21226964

Identification and Characterization of Distinct Apoptotic Pathways in Cancer Cells Activated in Response to Treatment with Different Anti-Cancer Agents

DTIC Science & Technology

2000-08-01

caspases precursors in different cell type induce apoptosis (Miura et al. 1993; Fernandes- 3 Alnemri et al. 1994; Kumar et al. 1994; Wang et al. 1994; Boldin ...association of ribosomes with mRNA. The lysates were sedimented through a linear sucrose gradient and fractions were collected. RNA was extracted from...precursors in different cell type induces apoptosis (Miura et al. 1993; Fernandes- Alnemri et al. 1994; Kumar et al. 1994; Wang et al. 1994; Boldin et al

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bihmidine, Saadia; Baker, R. Frank; Hoffner, Cassandra

Background: Sorghum (Sorghum bicolor L. Moench) cultivars store non-structural carbohydrates predominantly as either starch in seeds (grain sorghums) or sugars in stems (sweet sorghums). Previous research determined that sucrose accumulation in sweet sorghum stems was not correlated with the activities of enzymes functioning in sucrose metabolism, and that an apoplasmic transport step may be involved in stem sucrose accumulation. However, the sucrose unloading pathway from stem phloem to storage parenchyma cells remains unelucidated. Sucrose transporters (SUTs) transport sucrose across membranes, and have been proposed to function in sucrose partitioning differences between sweet and grain sorghums. The purpose of this studymore » was to characterize the key differences in carbohydrate accumulation between a sweet and a grain sorghum, to define the path sucrose may follow for accumulation in sorghum stems, and to determine the roles played by sorghum SUTs in stem sucrose accumulation. Results: Dye tracer studies to determine the sucrose transport route revealed that, for both the sweet sorghum cultivar Wray and grain sorghum cultivar Macia, the phloem in the stem veins was symplasmically isolated from surrounding cells, suggesting sucrose was apoplasmically unloaded. Once in the phloem apoplasm, a soluble tracer diffused from the vein to stem parenchyma cell walls, indicating the lignified mestome sheath encompassing the vein did not prevent apoplasmic flux outside of the vein. To characterize carbohydrate partitioning differences between Wray and Macia, we compared the growth, stem juice volume, solute contents, SbSUTs gene expression, and additional traits. Contrary to previous findings, we detected no significant differences in SbSUTs gene expression within stem tissues. Conclusions: Phloem sieve tubes within sweet and grain sorghum stems are symplasmically isolated from surrounding cells; hence, unloading from the phloem likely occurs apoplasmically, thereby defining the location of the previously postulated step for sucrose transport. Additionally, no changes in SbSUTs gene expression were detected in sweet vs. grain sorghum stems, suggesting alterations in SbSUT transcript levels do not account for the carbohydrate partitioning differences between cultivars. A model illustrating sucrose phloem unloading and movement to stem storage parenchyma, and highlighting roles for sucrose transport proteins in sorghum stems is discussed.« less

Cryopreservation of Cyrtopodium hatschbachii Pabst (Orchidaceae) immature seeds by encapsulation-dehydration.

PubMed

Surenciski, Mauro Rodrigo; Flachsland, Eduardo Alberto; Terada, Graciela; Mroginski, Luis Amado; Rey, Hebe Yolanda

2012-04-01

The aim of the present study was to investigate the efficiency of the encapsulation-dehydration technique for cryopreservation of Cyrtopodium hastchbachii Pabst seeds. Immature seeds of this species were cryopreserved by an encapsulation-dehydration technique. Seeds of five immature pods, 120 days after pollination, were encapsulated in 3% calcium alginate matrix and pretreated in liquid medium supplemented with 0.08 M sucrose (24 h), 0.15 M sucrose (24 h), 0.25 M sucrose (48 h), 0.5 M sucrose (24 h) and 0.75 M sucrose (24 h) in shaker at 60 rpm. Alginate beads were dehydrated 5 h in silicagel and immersed in liquid nitrogen for 12 h. Cryopreserved beads were thawed at 30 degrees C for 1 min, rehydrated using the same liquid mediums [0.75 M sucrose (24 h), 0.5 M sucrose (24 h), 0.25 M sucrose (48 h) and 0.15 M sucrose (24 h)] and cultivated in half strength Murashige & Skoog medium (1962) with the addition of 2 g/L activated charcoal. Sixty four percent of seeds survived and developed into acclimatized plants after being cryopreserved. In this work, the encapsulation-dehydration technique was employed for first time in Cyrtopodium hatschbachii.

Rats’ preferences for high fructose corn syrup vs. sucrose and sugar mixtures

PubMed Central

Ackroff, Karen; Sclafani, Anthony

2011-01-01

High fructose corn syrup (HFCS) has replaced sucrose in many food products, which has prompted research comparing these two sweeteners in rodents. The present study examined the relative palatability of HFCS and sucrose for rats, offering 11% carbohydrate solutions to match the content of common beverages for human consumption. The animals initially preferred HFCS to sucrose but after separate experience with each solution they switched to sucrose preference. Approximating the composition of HFCS with a mixture of fructose and glucose (55:45) yielded a solution that was less attractive than sucrose or HFCS. However, HFCS contains a small amount of glucose polymers, which are very attractive to rats. A 55:42:3 mixture of fructose, glucose and glucose polymers (Polycose) was equally preferred to HFCS and was treated similarly to HFCS in comparisons vs. sucrose. Post-oral effects of sucrose, which is 50% fructose and 50% glucose, may be responsible for the shift in preference with experience. This shift, and the relatively small magnitude of differences in preference for HFCS and sucrose, suggest that palatability factors probably do not contribute to any possible difference in weight gain responses to these sweeteners. PMID:21236278

Rats' preferences for high fructose corn syrup vs. sucrose and sugar mixtures.

PubMed

Ackroff, Karen; Sclafani, Anthony

2011-03-28

High fructose corn syrup (HFCS) has replaced sucrose in many food products, which has prompted research comparing these two sweeteners in rodents. The present study examined the relative palatability of HFCS and sucrose for rats, offering 11% carbohydrate solutions to match the content of common beverages for human consumption. The animals initially preferred HFCS to sucrose but after separate experience with each solution they switched to sucrose preference. Approximating the composition of HFCS with a mixture of fructose and glucose (55:45) yielded a solution that was less attractive than sucrose or HFCS. However, HFCS contains a small amount of glucose polymers, which are very attractive to rats. A 55:42:3 mixture of fructose, glucose and glucose polymers (Polycose) was equally preferred to HFCS and was treated similarly to HFCS in comparisons vs. sucrose. Post-oral effects of sucrose, which is 50% fructose and 50% glucose, may be responsible for the shift in preference with experience. This shift, and the relatively small magnitude of differences in preference for HFCS and sucrose, suggest that palatability factors probably do not contribute to any possible difference in weight gain responses to these sweeteners. Copyright © 2011 Elsevier Inc. All rights reserved.

The Sucrose Synthase Gene Family in Chinese Pear (Pyrus bretschneideri Rehd.): Structure, Expression, and Evolution.

PubMed

Abdullah, Muhammad; Cao, Yungpeng; Cheng, Xi; Meng, Dandan; Chen, Yu; Shakoor, Awais; Gao, Junshan; Cai, Yongping

2018-05-11

Sucrose synthase (SS) is a key enzyme involved in sucrose metabolism that is critical in plant growth and development, and particularly quality of the fruit. Sucrose synthase gene families have been identified and characterized in plants various plants such as tobacco, grape, rice, and Arabidopsis . However, there is still lack of detailed information about sucrose synthase gene in pear. In the present study, we performed a systematic analysis of the pear ( Pyrus bretschneideri Rehd.) genome and reported 30 sucrose synthase genes. Subsequently, gene structure, phylogenetic relationship, chromosomal localization, gene duplications, promoter regions, collinearity, RNA-Seq data and qRT-PCR were conducted on these sucrose synthase genes. The transcript analysis revealed that 10 PbSSs genes (30%) were especially expressed in pear fruit development. Additionally, qRT-PCR analysis verified the RNA-seq data and shown that PbSS30 , PbSS24 , and PbSS15 have a potential role in the pear fruit development stages. This study provides important insights into the evolution of sucrose synthase gene family in pear and will provide assistance for further investigation of sucrose synthase genes functions in the process of fruit development, fruit quality and resistance to environmental stresses.

Molecular cloning and functional characterization of the apple sucrose transporter gene MdSUT2.

PubMed

Ma, Qi-Jun; Sun, Mei-Hong; Liu, Ya-Jing; Lu, Jing; Hu, Da-Gang; Hao, Yu-Jin

2016-12-01

Sucrose is not only the primary photosynthetic product but also the major component translocated in the phloem of economically important plant species. Sucrose transporters or carriers (SUTs or SUCs), function as sucrose/H + symporters and play a crucial role in determining the cell-to-cell distribution of sucrose throughout the entire plant. However, whether such genes are involved in responses to abiotic stress and other biological processes is largely unknown. Here, we report that MdSUT2 in apple is a homolog of the Arabidopsis vacuolar sucrose transporter AtSUT2. Ectopic expression of MdSUT2 in Arabidopsis decreased sucrose sensitivity in germination and seeding stage and increased sucrose transport activity. In addition, our results showed that MdSUT2 impacted on plant growth by accelerating vegetative growth and promoting early flowering in Arabidopsis. Overexpression of MdSUT2 significantly improved abiotic stress tolerance including NaCl, ABA, and mannitol in apple calli and Arabidopsis. Together, these findings provide evidence that the apple sucrose transporter MdSUT2 is involved in abiotic stress resistance and the regulation of plant growth and development. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

77 FR 18827 - Draft Guidance for Industry on Bioequivalence Recommendations for Iron Sucrose Injection...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-03-28

...] Draft Guidance for Industry on Bioequivalence Recommendations for Iron Sucrose Injection; Availability... Recommendations for Iron Sucrose.'' The recommendations provide specific guidance on the design of bioequivalence (BE) studies to support abbreviated new drug applications (ANDAs) for iron sucrose injection. DATES...

Dietary sucrose is essential to the development of liver injury in the methionine-choline-deficient model of steatohepatitis.

PubMed

Pickens, Michael K; Yan, Jim S; Ng, Raymond K; Ogata, Hisanobu; Grenert, James P; Beysen, Carine; Turner, Scott M; Maher, Jacquelyn J

2009-10-01

Methionine-choline-deficient (MCD) diets cause steatohepatitis in rodents and are used to study the pathophysiology of fatty liver disease in human beings. The most widely used commercial MCD formulas not only lack methionine and choline but also contain excess sucrose and fat. The objective of this study was to determine whether dietary sucrose in the MCD formula plays a role in the pathogenesis of MCD-related liver disease. We prepared two custom MCD formulas, one containing sucrose as the principal carbohydrate and the other substituting sucrose with starch. Mice fed the sucrose-enriched formula developed typical features of MCD-related liver disease, including hepatic steatosis, hepatocellular apoptosis, alanine aminotransferase elevation, lipid peroxidation, and hepatic inflammation. In contrast, mice fed MCD-starch were significantly protected against liver injury. MCD-sucrose and MCD-starch mice displayed identical diet-related abnormalities in hepatic fatty acid uptake and triglyceride secretion. Hepatic de novo lipogenesis and triglyceride synthesis, however, were 2 times higher in MCD-sucrose mice than MCD-starch mice (P < 0.01). Hepatic lipid analysis revealed accumulation of excess saturated fatty acids in MCD-sucrose mice that correlated with hepatocellular injury. Overall, the results indicate that dietary sucrose is critical to the pathogenesis of MCD-mediated steatohepatitis. They suggest that saturated fatty acids, which are products of de novo lipogenesis, are mediators of hepatic toxicity in this model of liver disease.

Interaction of Metabolic Stress with Chronic Mild Stress in Altering Brain Cytokines and Sucrose Preference

PubMed Central

Remus, Jennifer L.; Stewart, Luke T.; Camp, Robert M.; Novak, Colleen M.; Johnson, John D.

2015-01-01

There is growing evidence that metabolic stressors increase an organism’s risk of depression. Chronic mild stress is a popular animal model of depression and several serendipitous findings have suggested that food deprivation prior to sucrose testing in this model is necessary to observe anhedonic behaviors. Here, we directly tested this hypothesis by exposing animals to chronic mild stress and used an overnight two bottle sucrose test (food ad libitum) on day 5 and 10, then food and water deprive animals overnight and tested their sucrose consumption and preference in a 1h sucrose test the following morning. Approximately 65% of stressed animals consumed sucrose and showed a sucrose preference similar to non-stressed controls in an overnight sucrose test, while 35% showed a decrease in sucrose intake and preference. Following overnight food and water deprivation the previously ‘resilient’ animals showed a significant decrease in sucrose preference and greatly reduced sucrose intake. In addition, we evaluated whether the onset of anhedonia following food and water deprivation corresponds to alterations in corticosterone, epinephrine, circulating glucose, or interleukin-1 beta expression in limbic brain areas. While all stressed animals showed adrenal hypertrophy and elevated circulating epinephrine, only stressed animals that were food deprived were hypoglycemic compared to food deprived controls. Additionally, food and water deprivation significantly increased hippocampus IL-1β while food and water deprivation only increased hypothalamus IL-1β in stress susceptible animals. These data demonstrate that metabolic stress of food and water deprivation interacts with chronic stressor exposure to induce physiological and anhedonic responses. PMID:25914924

Phloem-localized, proton-coupled sucrose carrier ZmSUT1 mediates sucrose efflux under the control of the sucrose gradient and the proton motive force.

PubMed

Carpaneto, Armando; Geiger, Dietmar; Bamberg, Ernst; Sauer, Norbert; Fromm, Jörg; Hedrich, Rainer

2005-06-03

The phloem network is as essential for plants as the vascular system is for humans. This network, assembled by nucleus- and vacuole-free interconnected living cells, represents a long distance transport pathway for nutrients and information. According to the Münch hypothesis, osmolytes such as sucrose generate the hydrostatic pressure that drives nutrient and water flow between the source and the sink phloem (Münch, E. (1930) Die Stoffbewegungen in der Pflanze, Gustav Fischer, Jena, Germany). Although proton-coupled sucrose carriers have been localized to the sieve tube and the companion cell plasma membrane of both source and sink tissues, knowledge of the molecular representatives and the mechanism of the sucrose phloem efflux is still scant. We expressed ZmSUT1, a maize sucrose/proton symporter, in Xenopus oocytes and studied the transport characteristics of the carrier by electrophysiological methods. Using the patch clamp techniques in the giant inside-out patch mode, we altered the chemical and electrochemical gradient across the sucrose carrier and analyzed the currents generated by the proton flux. Thereby we could show that ZmSUT1 is capable of mediating both the sucrose uptake into the phloem in mature leaves (source) as well as the desorption of sugar from the phloem vessels into heterotrophic tissues (sink). As predicted from a perfect molecular machine, the ZmSUT1-mediated sucrose-coupled proton current was reversible and depended on the direction of the sucrose and pH gradient as well as the membrane potential across the transporter.

13C-Breath Tests for Sucrose Digestion in Congenital Sucrase Isomaltase Deficient and Sacrosidase Supplemented Patients

PubMed Central

Robayo-Torres, Claudia C.; Opekun, Antone R.; Quezada-Calvillo, Roberto; Xavier, Villa; Smith, E. O’Brian; Navarrete, Marilyn; Baker, S. Susan; Nichols, Buford L

2008-01-01

Congenital sucrase-isomaltase deficiency (CSID) is characterized by absence or deficiency of the mucosal sucrase-isomaltase enzyme. Specific diagnosis requires upper gastrointestinal biopsy with evidence of low to absent sucrase enzyme activity and normal histology. The hydrogen breath test (BT) is useful but is not specific for confirmation of CSID. We investigated a more specific 13C-sucrose labeled BT. Objectives were to determine if CSID can be detected with the 13C-sucrose BT without duodenal biopsy sucrase assay and if the 13C-sucrose BT can document restoration of sucrose digestion by CSID patients after oral supplementation with sacrosidase (Sucraid®). Methods Ten CSID patients were diagnosed by low biopsy sucrase activity. Ten controls were children who underwent endoscopy and biopsy because of dyspepsia or chronic diarrhea with normal mucosal enzymes activity and histology. Uniformly-labeled 13C-glucose and 13C-sucrose loads were orally administered. 13CO2 breath enrichments were assayed using an infrared spectrophotometer. In CSID patients the 13C-sucrose load was repeated adding Sucraid®. Sucrose digestion and oxidation were calculated as a mean % coefficient of glucose oxidation (% CGO) averaged between 30 and 90 minutes. Results Classification of patients by 13C-sucrose BT % CGO agreed with biopsy sucrase activity. The breath test also documented the return to normal of sucrose digestion and oxidation after supplementation of CSID patients with Sucraid®. Conclusion 13C-sucrose BT is an accurate and specific non-invasive confirmatory test for CSID and for enzyme replacement management. PMID:19330928

Sucrose importation into laticifers of Hevea brasiliensis, in relation to ethylene stimulation of latex production

PubMed Central

Dusotoit-Coucaud, Anaïs; Brunel, Nicole; Kongsawadworakul, Panida; Viboonjun, Unchera; Lacointe, André; Julien, Jean-Louis; Chrestin, Hervé; Sakr, Soulaïman

2009-01-01

Background and Aims The major economic product of Hevea brasiliensis is a rubber-containing cytoplasm (latex), which flows out of laticifers (latex cells) when the bark is tapped. The latex yield is stimulated by ethylene. Sucrose, the unique precursor of rubber synthesis, must cross the plasma membrane through specific sucrose transporters before being metabolized in the laticifers. The relative importance of sucrose transporters in determining latex yield is unknown. Here, the effects of ethylene (by application of Ethrel®) on sucrose transporter gene expression in the inner bark tissues and latex cells of H. brasiliensis are described. Methods Experiments, including cloning sucrose transporters, real time RT-PCR and in situ hybridization, were carried out on virgin (untapped) trees, treated or untreated with the latex yield stimulant Ethrel. Key Results Seven putative full-length cDNAs of sucrose transporters were cloned from a latex-specific cDNA library. These transporters belong to all SUT (sucrose transporter) groups and differ by their basal gene expression in latex and inner soft bark, with a predominance of HbSUT1A and HbSUT1B. Of these sucrose transporters, only HbSUT1A and HbSUT2A were distinctly increased by ethylene. Moreover, this increase was shown to be specific to laticifers and to ethylene application. Conclusion The data and all previous information on sucrose transport show that HbSUT1A and HbSUT2A are related to the increase in sucrose import into laticifers, required for the stimulation of latex yield by ethylene in virgin trees. PMID:19567416

Sugar Beet, Energy Beet, and Industrial Beet

USDA-ARS?s Scientific Manuscript database

Sugar beet (Beta vulgaris) is a temperate root crop grown primarily as a source of sucrose for human diets. Breeding has focused on sucrose yield, which is simply the product of total root yield times the proportion of sucrose in the harvested roots, minus loss of sucrose in molasses due to impuriti...

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rivera, S.; Lugo, T.; Hazen, T.C.

Water and shellfish samples collected from estuaries, mangroves, and beaches along the coast of Puerto Rico were examined for Vibrio vulnificus and Vibrio parahaemolyticus. An array of water quality parameters were also measured simultaneous with bacteria sampling. Both species of vibrio were associated with estuary and mangrove locations, and neither was isolated from sandy beaches. Densities of V. vulnificus were negatively correlated with salinity, 10--15 ppt being optimal. V. parahaemolyticus was isolated from sites with salinities between 20 and 35 ppt, the highest densities occurring at 20 ppt. Densities of Vibrio spp. and V. parahaemolyticus for a tropical estuary surpassedmore » those reported for temperate estuaries by several orders of magnitude. Both densities of total Vibrio spp. and V. parahaemolyticus in the water were directly related to densities of fecal coliforms, unlike V. vulnificus. The incidence of ONPG(+) strains among sucrose({minus}) Vibrio spp. served as an indicator of the frequency of V. vulnificus in this group. More than 63% of the V. vulnificus isolated were pathogenic. V. vulnificus and V. parahaemolyticus occupy clearly separate niches within the tropical estuarine-marine ecosystem.« less

Red fluorescent biofilm: the thick, the old, and the cariogenic

PubMed Central

Volgenant, Catherine M.C.; Hoogenkamp, Michel A.; Buijs, Mark J.; Zaura, Egija; ten Cate, Jacob (Bob) M.; van der Veen, Monique H.

2016-01-01

Background Some dental plaque fluoresces red. The factors involved in this fluorescence are yet unknown. Objective The aim of this study was to assess systematically the effect of age, thickness, and cariogenicity on the extent of red fluorescence produced by in vitro microcosm biofilms. Design The effects of biofilm age and thickness on red fluorescence were tested in a constant depth film fermentor (CDFF) by growing biofilms of variable thicknesses that received a constant supply of defined mucin medium (DMM) and eight pulses of sucrose/day. The influence of cariogenicity on red fluorescence was tested by growing biofilm on dentin disks receiving DMM, supplemented with three or eight pulses of sucrose/day. The biofilms were analyzed at different time points after inoculation, up to 24 days. Emission spectra were measured using a fluorescence spectrophotometer (λexc405 nm) and the biofilms were photographed with a fluorescence camera. The composition of the biofilms was assessed using 454-pyrosequecing of the 16S rDNA gene. Results From day 7 onward, the biofilms emitted increasing intensities of red fluorescence as evidenced by the combined red fluorescence peaks. The red fluorescence intensity correlated with biofilm thickness but not in a linear way. Biofilm fluorescence also correlated with the imposed cariogenicity, evidenced by the induced dentin mineral loss. Increasing the biofilm age or increasing the sucrose pulsing frequency led to a shift in the microbial composition. These shifts in composition were accompanied by an increase in red fluorescence. Conclusions The current study shows that a thicker, older, or more cariogenic biofilm results in a higher intensity of red fluorescence. PMID:27060056

18-Methoxycoronaridine, a potential anti-obesity agent, does not produce a conditioned taste aversion in rats

PubMed Central

Taraschenko, Olga D.; Maisonneuve, Isabelle M.; Glick, Stanley D.

2015-01-01

18-Methoxycoronaridine (18-MC), a selective antagonist of α3β4 nicotinic receptors, has been shown to reduce the self-administration of several drugs of abuse. Recently, this agent has also been shown to attenuate sucrose reward, decrease sucrose intake and prevent the development of sucrose-induced obesity in rats. The present experiments were designed to determine whether the latter effect was due to an 18-MC-induced conditioned taste aversion to sucrose. Both 18-MC (20 mg/ kg, i.p.) and control agent, lithium chloride (100 mg/kg, i.p.), reduced sucrose intake 24 h after association with sucrose; however, only lithium chloride reduced sucrose intake 72h later. Consistent with previous data, 18-MC appears to have proactive effect for 24h and it does not induce a conditioned taste aversion. PMID:20457177

Effects of Sugar (Sucrose) on Children's Behavior.

ERIC Educational Resources Information Center

Rosen, Lee A.; And Others

1988-01-01

Examined effects of sugar on behavior of 45 preschool and elementary school children. Provided all children with basic breakfast that included drink containing either 50 g of sucrose, a comparably sweet placebo, or very little sucrose. Found some small behavior changes in high-sucrose group. All effects were small in magnitude and not considered…

Sucrose metabolism and growth in transplanted loblolly pine seedlings

Treesearch

Shi-Jean S. Sung; C.C. Black; Paul P. Kormanik

1993-01-01

Loblolly pine (Pinus taeda L.) seedling height, root collar diameter, and the specific activities of three sucrose metabolizing enzymes, namely, sucrose synthase (SS), acid invertase, and neutral invertase, were measured to assess seedling responses to transplant stress. It was concluded that i) SS was the dominant enzyme for sucrose metabolism in...

[Sucrose reward promotes rats' motivation for cocaine].

PubMed

Li, Yan-Qing; LE, Qiu-Min; Yu, Xiang-Chen; Ma, Lan; Wang, Fei-Fei

2016-06-25

Caloric diet, such as fat and sugar intake, has rewarding effects, and has been indicated to affect the responses to addictive substances in animal experiments. However, the possible association between sucrose reward and the motivation for addictive drugs remains to be elucidated. Thus, we carried out behavioral tests after sucrose self-administration training to determine the effects of sucrose experience on rats' motivation for cocaine, locomotor sensitivity to cocaine, basal locomotor activity, anxiety level, and associative learning ability. The sucrose-experienced (sucrose) group exhibited higher lever press, cocaine infusion and break point, as well as upshift of cocaine dose-response curve in cocaine self-administration test, as compared with the control (chow) group. Additionally, despite similar locomotor activity in open field test and comparable score in cocaine-induced conditioned place preference, the sucrose group showed higher cocaine-induced locomotor sensitivity as compared with the chow group. The anxiety level and the performance in vocal-cue induced fear memory were similar between these two groups in elevated plus maze and fear conditioning tests, respectively. Taken together, our work indicates that sucrose experience promotes the rats' motivation for cocaine.

Alcohol outlet density and assault: a spatial analysis.

PubMed

Livingston, Michael

2008-04-01

A large number of studies have found links between alcohol outlet densities and assault rates in local areas. This study tests a variety of specifications of this link, focusing in particular on the possibility of a non-linear relationship. Cross-sectional data on police-recorded assaults during high alcohol hours, liquor outlets and socio-demographic characteristics were obtained for 223 postcodes in Melbourne, Australia. These data were used to construct a series of models testing the nature of the relationship between alcohol outlet density and assault, while controlling for socio-demographic factors and spatial auto-correlation. Four types of relationship were examined: a normal linear relationship between outlet density and assault, a non-linear relationship with potential threshold or saturation densities, a relationship mediated by the socio-economic status of the neighbourhood and a relationship which takes into account the effect of outlets in surrounding neighbourhoods. The model positing non-linear relationships between outlet density and assaults was found to fit the data most effectively. An increasing accelerating effect for the density of hotel (pub) licences was found, suggesting a plausible upper limit for these licences in Melbourne postcodes. The study finds positive relationships between outlet density and assault rates and provides evidence that this relationship is non-linear and thus has critical values at which licensing policy-makers can impose density limits.

Sucrose and Saccharomyces cerevisiae: a relationship most sweet.

PubMed

Marques, Wesley Leoricy; Raghavendran, Vijayendran; Stambuk, Boris Ugarte; Gombert, Andreas Karoly

2016-02-01

Sucrose is an abundant, readily available and inexpensive substrate for industrial biotechnology processes and its use is demonstrated with much success in the production of fuel ethanol in Brazil. Saccharomyces cerevisiae, which naturally evolved to efficiently consume sugars such as sucrose, is one of the most important cell factories due to its robustness, stress tolerance, genetic accessibility, simple nutrient requirements and long history as an industrial workhorse. This minireview is focused on sucrose metabolism in S. cerevisiae, a rather unexplored subject in the scientific literature. An analysis of sucrose availability in nature and yeast sugar metabolism was performed, in order to understand the molecular background that makes S. cerevisiae consume this sugar efficiently. A historical overview on the use of sucrose and S. cerevisiae by humans is also presented considering sugarcane and sugarbeet as the main sources of this carbohydrate. Physiological aspects of sucrose consumption are compared with those concerning other economically relevant sugars. Also, metabolic engineering efforts to alter sucrose catabolism are presented in a chronological manner. In spite of its extensive use in yeast-based industries, a lot of basic and applied research on sucrose metabolism is imperative, mainly in fields such as genetics, physiology and metabolic engineering. © FEMS 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

An in vivo invertebrate evaluation system for identifying substances that suppress sucrose-induced postprandial hyperglycemia

PubMed Central

Matsumoto, Yasuhiko; Ishii, Masaki; Sekimizu, Kazuhisa

2016-01-01

Sucrose is a major sweetener added to various foods and beverages. Excessive intake of sucrose leads to increases in blood glucose levels, which can result in the development and exacerbation of lifestyle-related diseases such as obesity and diabetes. In this study, we established an in vivo evaluation system using silkworms to explore substances that suppress the increase in blood glucose levels caused by dietary intake of sucrose. Silkworm hemolymph glucose levels rapidly increased after intake of a sucrose-containing diet. Addition of acarbose or voglibose, α-glycosidase inhibitors clinically used for diabetic patients, suppressed the dietary sucrose-induced increase in the silkworm hemolymph glucose levels. Screening performed using the sucrose-induced postprandial hyperglycemic silkworm model allowed us to identify some lactic acid bacteria that inhibit the increase in silkworm hemolymph glucose levels caused by dietary intake of sucrose. The inhibitory effects of the Lactococcus lactis #Ll-1 bacterial strain were significantly greater than those of different strains of lactic acid bacteria. No effect of the Lactococcus lactis #Ll-1 strain was observed in silkworms fed a glucose diet. These results suggest that the sucrose diet-induced postprandial hyperglycemic silkworm is a useful model for evaluating chemicals and lactic acid bacteria that suppress increases in blood glucose levels. PMID:27194587

An in vivo invertebrate evaluation system for identifying substances that suppress sucrose-induced postprandial hyperglycemia.

PubMed

Matsumoto, Yasuhiko; Ishii, Masaki; Sekimizu, Kazuhisa

2016-05-19

Sucrose is a major sweetener added to various foods and beverages. Excessive intake of sucrose leads to increases in blood glucose levels, which can result in the development and exacerbation of lifestyle-related diseases such as obesity and diabetes. In this study, we established an in vivo evaluation system using silkworms to explore substances that suppress the increase in blood glucose levels caused by dietary intake of sucrose. Silkworm hemolymph glucose levels rapidly increased after intake of a sucrose-containing diet. Addition of acarbose or voglibose, α-glycosidase inhibitors clinically used for diabetic patients, suppressed the dietary sucrose-induced increase in the silkworm hemolymph glucose levels. Screening performed using the sucrose-induced postprandial hyperglycemic silkworm model allowed us to identify some lactic acid bacteria that inhibit the increase in silkworm hemolymph glucose levels caused by dietary intake of sucrose. The inhibitory effects of the Lactococcus lactis #Ll-1 bacterial strain were significantly greater than those of different strains of lactic acid bacteria. No effect of the Lactococcus lactis #Ll-1 strain was observed in silkworms fed a glucose diet. These results suggest that the sucrose diet-induced postprandial hyperglycemic silkworm is a useful model for evaluating chemicals and lactic acid bacteria that suppress increases in blood glucose levels.

Plant, cell, and molecular mechanisms of abscisic-acid regulation of stomatal apertures. A new mechanism for the regulation of stomatal-aperture size in intact leaves: Accumulation of mesophyll-derived sucrose in the guard-cell wall of Vicia faba L.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lu, P.; Outlaw, W.H. Jr.; Smith, B.G.

At various times after pulse labeling Vicia faba L. leaflets with {sup 14}CO{sub 2}, whole-leaf pieces and rinsed epidermal peels were harvested and subsequently processed for histochemical analysis. Cells dissected from whole leaf retained apoplastic contents whereas those from rinsed peels contained only cytoplastic contents. Sucrose specific radioactivity peaked in palisade cells, 111 GBq{center_dot}mol{sup {minus}1}, at 20 min. In contrast, the {sup 14}C content and sucrose specific radioactivity were very low in guard cells for 20 min, implying little CO{sub 2} incorporation; both then peaked at 40 min. The guard-cell apoplast had a high maximum sucrose specific radioactivity and amore » high sucrose influx rate. These and other comparisons implied the presence of (a) multiple sucrose pools in mesophyll cells, (b) a localized mesophyll-apoplast region that exchanges with phloem and stomata, and (c) mesophyll-derived sucrose in guard-cell walls sufficient to diminish stomatal opening by {approximately} 4 {micro}m. Factors expected to enhance sucrose accumulation in guard-cell walls are (a) high transpiration rate, which closes stomata, and (b) high apoplastic sucrose concentration, which is elevated when mesophyll-sucrose efflux exceeds translocation. Therefore, multiple physiological factors are integrated in the attenuation of stomatal-aperture size by this previously unrecognized mechanism.« less

Polyhydroxyalkanoate production from sucrose by Cupriavidus necator strains harboring csc genes from Escherichia coli W.

PubMed

Arikawa, Hisashi; Matsumoto, Keiji; Fujiki, Tetsuya

2017-10-01

Cupriavidus necator H16 is the most promising bacterium for industrial production of polyhydroxyalkanoates (PHAs) because of their remarkable ability to accumulate them in the cells. With genetic modifications, this bacterium can produce poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBHHx), which has better physical properties, as well as poly(3-hydroxybutyrate) (PHB) using plant oils and sugars as a carbon source. Considering production cost, sucrose is a very attractive raw material because it is inexpensive; however, this bacterium cannot assimilate sucrose. Here, we used the sucrose utilization (csc) genes of Escherichia coli W to generate C. necator strains that can assimilate sucrose. Especially, glucose-utilizing recombinant C. necator strains harboring the sucrose hydrolase gene (cscA) and sucrose permease gene (cscB) of E. coli W grew well on sucrose as a sole carbon source and accumulated PHB. In addition, strains introduced with a crotonyl-CoA reductase gene (ccr), ethylmalonyl-CoA decarboxylase gene (emd), and some other genetic modifications besides the csc genes and the glucose-utilizing mutations produced PHBHHx with a 3-hydroxyhexanoate (3HHx) content of maximum approximately 27 mol% from sucrose. Furthermore, when one of the PHBHHx-producing strains was cultured with sucrose solution in a fed-batch fermentation, PHBHHx with a 3HHx content of approximately 4 mol% was produced and reached 113 g/L for 65 h, which is approximately 1.5-fold higher than that produced using glucose solution.

Sucrose consumption in Thai undergraduate students.

PubMed

Promdee, Limthong; Trakulthong, Jindara; Kangwantrakul, Wisut

2007-01-01

Highly added sugar diets have been associated with various health problems such as dental caries, dyslipidemia, obesity and poor quality of life. Unfortunately, sugar consumption, especially sucrose, has increased continuously worldwide. The purpose of the study was to examine sources of sugar consumption and amount of added sucrose consumed in Thai undergraduate students. This study was carried out at Khon Kaen University, Thailand, between the years 2004-2005. A complete 3-day record of items and amounts of sweet consumption were obtained from 202 individuals--38 male and 164 female students. Added sucrose content of each sweetened food and drinks referred to in the record was determined by an enzymatic method. Mean intakes of sucrose were calculated from the sucrose content. The average of sucrose consumption in all subjects was 69+/-38 g/day, ranged from 4 to 182 g/day or 17 teaspoons of added sucrose per day. This amount accounted for 13.8% of total daily energy intake. There was a record of 337 kinds of sweetened foods and drinks found. The major source of added sucrose consumption was sweetened beverage, which was consumed 118 g/day averagely, or 60% of daily sugar consumption. Intake of sucrose per day in both male and female was not statistically difference, neither among different BMI groups. Intake of added sugar in the students was higher than the recommendation of the World Health Organization. These data would be helpful in a health promotion campaign aimed at a reduction of sugar consumption in Thai undergraduate students.

[The efficacy of sucrose for the relief of pain in neonates: a systematic review of the literature].

PubMed

Gaspardo, Cláudia M; Linhares, Maria Beatriz M; Martinez, Francisco E

2005-01-01

To present a review of empirical studies published from 1993 to 2004 on the efficacy of sucrose solution for relieving pain in neonates. Information was obtained from the MEDLINE/PsycINFO/ISI WEB of SCIENCE/LILACS and SciELO databases by searching for "sucrose", "pain", "newborn" and "neonate". Sucrose solution has demonstrated efficacy in pain relief during puncture procedures on samples of preterm and fullterm neonates. The recommendation is to administer oral sucrose, to the front of the tongue, 2 minutes before the painful procedure. Other non-pharmacological interventions, such as human breastmilk via nasogastric tube, non-nutritional suckling and being held at the breast, also demonstrated synergic analgesic effects when administered in association with sucrose. The majority of studies demonstrated a positive pain relief effect with a single 2 ml dose at 25%. Conclusions could not be drawn on the best repeat administration scheme; in the few studies that did provide an indication, the dose was 0.1 ml at 24%. The analgesic pain relief effect promoted by the sucrose was observed through altered behavioral responses, facial activity and crying. Heart rate underwent larger reductions as a result of sucrose administration during painful procedures than any of the other physiological responses. The efficacy of a single dose of sucrose for the relief of acute pain neonates is well documented in the literature. However, there are not yet definite conclusions on the scheme of use for repeated doses of sucrose.

Sucrose or sucrose and caffeine differentially impact memory and anxiety-like behaviours, and alter hippocampal parvalbumin and doublecortin.

PubMed

Xu, Tanya J; Reichelt, Amy C

2018-04-11

Caffeinated sugar-sweetened "energy" drinks are a subset of soft drinks that are popular among young people worldwide. High sucrose diets impair cognition and alter aspects of emotional behaviour in rats, however, little is known about sucrose combined with caffeine. Rats were allocated to 2 h/day 10% sucrose (Suc), 10% sucrose plus 0.04% caffeine (CafSuc) or control (water) conditions. The addition of caffeine to sucrose appeared to increase the rewarding aspect of sucrose, as the CafSuc group consumed more solution than the Suc group. After 14 days of intermittent Suc or CafSuc access, anxiety was assessed in the elevated plus maze (EPM) prior to their daily solution access, whereby CafSuc and Suc rats spent more time in the closed arms, indicative of increased anxiety. Following daily solution access, CafSuc, but not Suc, rats showed reduced anxiety-like behaviour in the open-field. Control and CafSuc rats displayed intact place and long-term object memory, while Suc showed impaired memory performance. Sucrose reduced parvalbumin immunoreactivity in the hippocampus, but no differences were observed between Control and CafSuc conditions. Parvalbumin reactivity in the basolateral amygdala did not differ between conditions. Reduced doublecortin immunoreactivity in the dentate gyrus relative to controls was seen in the CafSuc, but not Suc, treatment conditions. These findings indicate that the addition of caffeine to sucrose attenuated cognitive deficits. However, the addition of caffeine to sucrose evoked anxiety-like responses under certain testing conditions, suggesting that frequent consumption of caffeinated energy drinks may promote emotional alterations and brain changes compared to standard soft drinks. Copyright © 2018 Elsevier Ltd. All rights reserved.

Identification of TPS family members in apple (Malus x domestica Borkh.) and the effect of sucrose sprays on TPS expression and floral induction.

PubMed

Du, Lisha; Qi, Siyan; Ma, Juanjuan; Xing, Libo; Fan, Sheng; Zhang, Songwen; Li, Youmei; Shen, Yawen; Zhang, Dong; Han, Mingyu

2017-11-01

Trehalose (α-D-glucopyranosyl α-D-glucopyranoside) is a non-reducing disaccharide that serves as a carbon source and stress protectant in apple trees. Trehalose-6-phosphate (T6P) is the biosynthetic precursor of trehalose. It functions as a crucial signaling molecule involved in the regulation of floral induction, and is closely related to sucrose. Trehalose-6-phosphate synthase (TPS) family members are pivotal components of the T6P biosynthetic pathway. The present study identified 13 apple TPS family members and characterized their expression patterns in different tissues and in response to exogenous application of sucrose during floral induction. 'Fuji' apple trees were sprayed with sucrose prior to the onset of floral induction. Bud growth, flowering rate, and endogenous sugar levels were then monitored. The expression of genes associated with sucrose metabolism and flowering were also characterized by RT-quantitative PCR. Results revealed that sucrose applications significantly improved flower production and increased bud size and fresh weight, as well as the sucrose content in buds and leaves. Furthermore, the expression of MdTPS1, 2, 4, 10, and 11 was rapidly and significantly up-regulated in response to the sucrose treatments. In addition, the expression levels of flowering-related genes (e.g., SPL genes, FT1, and AP1) also increased in response to the sucrose sprays. In summary, apple TPS family members were identified that may influence the regulation of floral induction and other responses to sucrose. The relationship between sucrose and T6P or TPS during the regulation of floral induction in apple trees is discussed. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Characterization, localization, and seasonal changes of the sucrose transporter FeSUT1 in the phloem of Fraxinus excelsior

PubMed Central

Öner-Sieben, Soner; Rappl, Christine; Sauer, Norbert; Stadler, Ruth; Lohaus, Gertrud

2015-01-01

Trees are generally assumed to be symplastic phloem loaders. A typical feature for most wooden species is an open minor vein structure with symplastic connections between mesophyll cells and phloem cells, which allow sucrose to move cell-to-cell through the plasmodesmata into the phloem. Fraxinus excelsior (Oleaceae) also translocates raffinose family oligosaccharides in addition to sucrose. Sucrose concentration was recently shown to be higher in the phloem sap than in the mesophyll cells. This suggests the involvement of apoplastic steps and the activity of sucrose transporters in addition to symplastic phloem-loading processes. In this study, the sucrose transporter FeSUT1 from F. excelsior was analysed. Heterologous expression in baker’s yeast showed that FeSUT1 mediates the uptake of sucrose. Immunohistochemical analyses revealed that FeSUT1 was exclusively located in phloem cells of minor veins and in the transport phloem of F. excelsior. Further characterization identified these cells as sieve elements and possibly ordinary companion cells but not as intermediary cells. The localization and expression pattern point towards functions of FeSUT1 in phloem loading of sucrose as well as in sucrose retrieval. FeSUT1 is most likely responsible for the observed sucrose gradient between mesophyll and phloem. The elevated expression level of FeSUT1 indicated an increased apoplastic carbon export activity from the leaves during spring and late autumn. It is hypothesized that the importance of apoplastic loading is high under low-sucrose conditions and that the availability of two different phloem-loading mechanisms confers advantages for temperate woody species like F. excelsior. PMID:26022258

Exogenous sucrose supply changes sugar metabolism and reduces photosynthesis of sugarcane through the down-regulation of Rubisco abundance and activity.

PubMed

Lobo, Ana Karla Moreira; de Oliveira Martins, Marcio; Lima Neto, Milton Costa; Machado, Eduardo Caruso; Ribeiro, Rafael Vasconcelos; Silveira, Joaquim Albenisio Gomes

2015-05-01

Photosynthetic modulation by sugars has been known for many years, but the biochemical and molecular comprehension of this process is lacking. We studied how the exogenous sucrose supplied to leaves could affect sugar metabolism in leaf, sheath and stalk and inhibit photosynthesis in four-month old sugarcane plants. Exogenous sucrose 50mM sprayed on attached leaves strongly impaired the net CO2 assimilation (PN) and decreased the instantaneous carboxylation efficiency (PN/Ci), suggesting that the impairment in photosynthesis was caused by biochemical restrictions. The photosystem II activity was also affected by excess sucrose as indicated by the reduction in the apparent electron transport rate, effective quantum yield and increase in non-photochemical quenching. In leaf segments, sucrose accumulation was related to increases in the activities of soluble acid and neutral invertases, sucrose synthase and sucrose phosphate synthase, whereas the contents of fructose increased and glucose slightly decreased. Changes in the activities of sucrose hydrolyzing and synthesizing enzymes in leaf, sheath and stalk and sugar profile in intact plants were not enough to identify which sugar(s) or enzyme(s) were directly involved in photosynthesis modulation. However, exogenous sucrose was able to trigger down-regulation in the Rubisco abundance, activation state and enzymatic activity. Despite the fact that PN/Ci had been notably decreased by sucrose, in vitro activity and abundance of PEPCase did not change, suggesting an in vivo modulation of this enzyme. The data reveal that sucrose and/or other derivative sugars in leaves inhibited sugarcane photosynthesis by down-regulation of Rubisco synthesis and activity. Our data also suggest that sugar modulation was not exerted by a feedback mechanism induced by the accumulation of sugars in immature sugarcane stalk. Copyright © 2015. Published by Elsevier GmbH.

The effects of nicotine self-administration and withdrawal on concurrently available chow and sucrose intake in adult male rats.

PubMed

Bunney, Patricia E; Burroughs, Danielle; Hernandez, Christine; LeSage, Mark G

2016-02-01

Carbohydrate intake, preference, and taste thresholds may be altered in current and former cigarette smokers, which may mediate weight gain and risk for obesity in individuals who quit smoking. Attempts to model these effects in rodents have primarily used noncontingent nicotine administration. The purpose of this research was to characterize changes in chow and sucrose intake in rats during a 23-h access model of i.v. nicotine self-administration (NSA), in which rats lever-pressed for chow, sucrose, and nicotine under concurrent fixed-ratio (FR) 1 schedules. Male rats were assigned to one of three groups that differed in food and drug availability. The Nicotine C+S group had concurrent access to nicotine, chow, and sucrose. The Saline C+S group had access to saline, chow, and sucrose. The Nicotine C-Only group had access to nicotine and chow, but not sucrose. Changes in food intake and weight gain were assessed during baseline, NSA, and nicotine withdrawal (i.e., saline extinction). Weight gain was significantly slowed during NSA and increased during withdrawal, but did not differ between the nicotine groups. NSA produced a significant decrease in both chow and sucrose intake. Gradual tolerance to nicotine's effects on sucrose, but not chow intake, occurred. During withdrawal, chow and sucrose intake increased, with a larger percent increase in sucrose intake compared to chow. The proportion of total food intake from sucrose was greater at the end of withdrawal compared to baseline, indicating a history of nicotine intake changed dietary preference. Combined, these results indicate that sucrose intake is more resistant to nicotine's appetite suppressant effects and withdrawal from nicotine produces a greater increase in sweet food intake alongside general increases in chow intake. Changes in overall food intake in current and ex-smokers may lead to increased risk for obesity and other health problems, potentially limiting the benefit of quitting smoking. Copyright © 2015 Elsevier Inc. All rights reserved.

Organ and Tissue-specific Sucrose Transporters. Important Hubs in Gene and Metabolite Networks Regulating Carbon Use in Wood-forming Tissues of Populus

DOE Office of Scientific and Technical Information (OSTI.GOV)

Harding, Scott A.; Tsai, Chung-Jui

The overall project objective was to probe the relationship between sucrose transporters and plant productivity in the biomass for biofuels woody perennial, Populus. At the time the proposal was written, sucrose transporters had already been investigated in many plant model systems, primarily with respect to the export of photosynthate sucrose from source leaves, and the uptake of sucrose in storage organs and seeds. Preliminary findings by the PI found that in Populus, sucrose transporter genes (SUTs) were well expressed in wood-forming tissues that comprise the feedstock for biofuels production. Because sucrose comprises by far the predominant form in which photosynthatemore » is delivered from source organs to sink organs like roots and wood-forming tissues, SUTs control a gate that nominally at least could impact the allocation or partitioning of sucrose for potentially competing end uses like growth (stem biomass) and storage. In addition, water use might be conditioned by the way in which sucrose is distributed throughout the plant, and/or by the way in which sucrose is partitioned intracellularly. Several dozen transgenic lines were produced in year 1 of the project to perturb the expression ratio of multiple plasma membrane (PM) SUTs (intercellular trafficking), versus the single tonoplast membrane (TM) sucrose transporter that effectively regulates intracellular trafficking of sucrose. It was possible to obtain transgenic lines with dual SUT gene knockdown using the 35S promoter, but not the wood-specific TUA1 promoter. By the end of project year 2, a decision was made to work with the 35S plants while archiving the TUA1 plants. The PhD candidate charged with producing the transgenic lines abandoned the project during its second year, substantially contributing to the decision to operate with just the 35S lines. That student’s interests ranged more toward evolutionary topics, and a report on SUT gene evolution was published (Peng et al 2014).« less

The effects of nicotine self-administration and withdrawal on concurrently available chow and sucrose intake in adult male rats

PubMed Central

Bunney, Patricia E.; Burroughs, Danielle; Hernandez, Christine; LeSage, Mark G

2016-01-01

Carbohydrate intake, preference, and taste thresholds may be altered in current and former cigarette smokers, which may mediate weight gain and risk for obesity in individuals who quit smoking. Attempts to model these effects in rodents have primarily used noncontingent nicotine administration. The purpose of this research was to characterize changes in chow and sucrose intake in rats during a 23-h access model of i.v. nicotine self-administration (NSA), in which rats lever-pressed for chow, sucrose, and nicotine under concurrent fixed-ratio (FR) 1 schedules. Male rats were assigned to one of three groups that differed in food and drug availability. The Nicotine C+S group had concurrent access to nicotine, chow, and sucrose. The Saline C+S group had access to saline, chow, and sucrose. The Nicotine C-Only group had access to nicotine and chow, but not sucrose. Changes in food intake and weight gain were assessed during baseline, NSA, and nicotine withdrawal (i.e., saline extinction). Weight gain was significantly slowed during NSA and increased during withdrawal, but did not differ between the nicotine groups. NSA produced a significant decrease in both chow and sucrose intake. Gradual tolerance to nicotine’s effects on sucrose, but not chow intake, occurred. During withdrawal, chow and sucrose intake increased, with a larger percent increase in sucrose intake compared to chow. The proportion of total food intake from sucrose was greater at the end of withdrawal compared to baseline, indicating a history of nicotine intake changed dietary preference. Combined, these results indicate that sucrose intake is more resistant to nicotine’s appetite suppressant effects and withdrawal from nicotine produces a greater increase in sweet food intake alongside general increases in chow intake. Changes in overall food intake in current and ex-smokers may lead to increased risk for obesity and other health problems, potentially limiting the benefit of quitting smoking. PMID:26548500

Feasibility study of sucrose and fat replacement using inulin and rebaudioside A in cake formulations.

PubMed

Majzoobi, Mahsa; Mohammadi, Mahshid; Mesbahi, Gholamreza; Farahnaky, Asgar

2018-02-20

Cake is a popular food around the world, however, it is considered as unhealthy due to its high fat and sucrose content. To satisfy customers' demand for a low fat and sucrose cake, in this research both sucrose and fat content of the cake were reduced by using rebaudioside A (Reb A; as a natural sucrose replacer) and inulin (as a natural fat replacer) at 0%, 25%, 50%, 75%, and 100%. The water content of different formulation was adjusted to obtain a constant batter viscosity similar to the control (3,757 cP). By reducing sucrose and fat content up to 50%, water activity increased and the cakes became more asymmetrical. However, other physical properties including baking weight loss, height, volume, crust color, and texture were similar to those of the control. Higher levels of replacement (75% and 100%) resulted in remarkable loss of different quality attributes. These samples showed higher water activity and baking loss, lower volume, harder texture, darker color, and highly asymmetrical shape. Thus, successful reduction of both fat and sucrose in cakes is possible by using inulin and Reb A at replacement levels no more than 50%. Customers' demand for healthy and yet tasty and high-quality foods is increasing around the world. Therefore, finding applicable and safe methods to produce such products is of great interest in the food manufacturing to satisfy customers. Health conscious customers avoid consumption of cakes because it contains high sucrose and fat content. Many studies have been performed to reduce either fat or sucrose content, while a few studies are available to show the reduction of both fat and sucrose in the same product. This study indicates the results of an applicable method to reduce fat and sucrose content of cakes simultaneously. Using rebaudioside A (as a natural sucrose replacer) and inulin (as a natural fat replacer) up to 50% of sucrose and fat content of cakes were reduced and the resulting cake had very similar physical properties to the control. © 2018 Wiley Periodicals, Inc.

Layered Lithium-Rich Oxide Nanoparticles Doped with Spinel Phase: Acidic Sucrose-Assistant Synthesis and Excellent Performance as Cathode of Lithium Ion Battery.

PubMed

Chen, Min; Chen, Dongrui; Liao, Youhao; Zhong, Xiaoxin; Li, Weishan; Zhang, Yuegang

2016-02-01

Nanolayered lithium-rich oxide doped with spinel phase is synthesized by acidic sucrose-assistant sol-gel combustion and evaluated as the cathode of a high-energy-density lithium ion battery. Physical characterizations indicate that the as-synthesized oxide (LR-SN) is composed of uniform and separated nanoparticles of about 200 nm, which are doped with about 7% spinel phase, compared to the large aggregated ones of the product (LR) synthesized under the same condition but without any assistance. Charge/discharge demonstrates that LR-SN exhibits excellent rate capability and cyclic stability: delivering an average discharge capacity of 246 mAh g(-1) at 0.2 C (1C = 250 mA g(-1)) and earning a capacity retention of 92% after 100 cycles at 4 C in the lithium anode-based half cell, compared to the 227 mA g(-1) and the 63% of LR, respectively. Even in the graphite anode-based full cell, LR-SN still delivers a capacity of as high as 253 mAh g(-1) at 0.1 C, corresponding to a specific energy density of 801 Wh kg(-1), which are the best among those that have been reported in the literature. The separated nanoparticles of the LR-SN provide large sites for charge transfer, while the spinel phase doped in the nanoparticles facilitates lithium ion diffusion and maintains the stability of the layered structure during cycling.

Characterization of outer membranes isolated from Treponema pallidum, the syphilis spirochete.

PubMed

Radolf, J D; Robinson, E J; Bourell, K W; Akins, D R; Porcella, S F; Weigel, L M; Jones, J D; Norgard, M V

1995-11-01

Previous freeze-fracture electron microscopy (EM) studies have shown that the outer membrane (OM) of Treponema pallidum contains sparse transmembrane proteins. One strategy for molecular characterization of these rare OM proteins involves isolation of T. pallidum OMs. Here we describe a simple and extremely gentle method for OM isolation based upon isopycnic sucrose density gradient ultracentrifugation of treponemes following plasmolysis in 20% sucrose. Evidence that T. pallidum OMs were isolated included (i) the extremely low protein/lipid ratio of the putative OM fraction, (ii) a paucity of antigenic and/or biochemical markers for periplasmic, cytoplasmic membrane, and cytosolic compartments, and (iii) freeze-fracture EM demonstrating that the putative OMs contained intramembranous particles highly similar in size and density to those in native T. pallidum OMs. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis revealed that the OMs contained a relatively small number of treponemal proteins, including several which did not appear to correspond to previously characterized T. pallidum antigens. Interestingly, these candidate rare OM proteins reacted poorly with syphilitic sera as determined by both conventional immunoblotting and enhanced chemiluminescence. Compared with whole cells, T. pallidum OMs were deficient in cardiolipin, the major lipoidal antigen reactive with antibodies in syphilitic sera. Also noteworthy was that other lipoidal constituents of OMs, including the recently discovered glycolipids, did not react with human syphilitic sera. These latter observations suggest that the poor antigenicity of virulent T. pallidum is a function of both the lipid composition and the low protein content of its OM.

A biochemical assessment of the value of top clipping nursery-grown loblolly pine seedlings

Treesearch

Shi-Jean S. Sung; Paul P. Kormanik; C.C. Black

1994-01-01

Seasonal sucrose metabolism (sucrolysis) was studied in taproot cambial tissues of nursery-grown loblolly pine seedlings to assess the value of top clipping. In sucrose-importing taproots of nonclipped seedlings, sucrose synthase (SS) was the dominant enzyme for sucrose cleavage, and its activity exhibited a distinct seasonal activity. Both root SS activity and...

Sucrose synthase in wild tomato Lycopersicon chmielewskii and tomato fruit sink strength

Treesearch

Shi-Jean S. Sung; T. Loboda; S.S. Sung; C.C. Black

1992-01-01

Here it is reported that sucrose synthase can be readily measured in growing wild tomato fruits (Lycopersicon chmielewskii) when suitable methods are adopted during fruit extraction. The enzyme also was present in fruit pericarp tissues, in seeds, and in flowers.In mature, nongrowing fruits, sucrose synthase activities approached nil values.Therefore, sucrose synthase...

Growth, sucrose synthase, and invertase activities of developing Phaseolus vulgaris L. fruits

Treesearch

Shi-Jean S. Sung; W.J. Sheih; D.R. Geiger; C.C. Black

1994-01-01

Activities of sucrose-cleaving enzymes, acid and neutral invertase and sucrose synthase, were measured in pods and seeds of developing snap bean (Phaseolus vulgaris L.) fruits, and compared with 14C-import, elongation and dry weight accumulation. The data supports the association of specific sucrose-cleaving enzymes with the specific processes that occur in the...

Effect of blowing agents on the oxidation resistance of carbon foams prepared from molten sucrose

NASA Astrophysics Data System (ADS)

Narasimman, R.; Prabhakaran, K.

2013-06-01

We have prepared low density carbon foams from molten sucrose using aluminium nitrate and boric acid blowing agents. A comparative study of the oxidation resistance of the carbon foams prepared using the two blowing agents are reported in the present paper. Oxidation of the carbon foams was evaluated under isothermal and non-isothermal conditions in air atmosphere using thermogravimetric analysis (TGA). We have observed that the alumina produced from the aluminium nitrate blowing agent acts as a catalyst whereas the boron produced from boric acid inhibits the oxidation of the carbon foams. The oxidation resistance of carbon foams increases with boron concentration. The oxidation onset temperature for the carbon foams prepared using boric acid blowing agent was nearly 60°C higher than that prepared using aluminium nitrate blowing agent. Carbon foams prepared using aluminium nitrate blowing agent undergoes complete oxidation at temperature less than 700°C. Whereas that prepared using boric acid blowing agent leave ˜ 50 wt.% residue at 900°C. Further evidence is provided by the kinetic analysis of the TGA using Coats-Redfern (CR) equation.

Sintering behavior and mechanical properties of zirconia compacts fabricated by uniaxial press forming.

PubMed

Oh, Gye-Jeong; Yun, Kwi-Dug; Lee, Kwang-Min; Lim, Hyun-Pil; Park, Sang-Won

2010-09-01

The purpose of this study was to compare the linear sintering behavior of presintered zirconia blocks of various densities. The mechanical properties of the resulting sintered zirconia blocks were then analyzed. Three experimental groups of dental zirconia blocks, with a different presintering density each, were designed in the present study. Kavo Everest® ZS blanks (Kavo, Biberach, Germany) were used as a control group. The experimental group blocks were fabricated from commercial yttria-stabilized tetragonal zirconia powder (KZ-3YF (SD) Type A, KCM. Corporation, Nagoya, Japan). The biaxial flexural strengths, microhardnesses, and microstructures of the sintered blocks were then investigated. The linear sintering shrinkages of blocks were calculated and compared. Despite their different presintered densities, the sintered blocks of the control and experimental groups showed similar mechanical properties. However, the sintered block had different linear sintering shrinkage rate depending on the density of the presintered block. As the density of the presintered block increased, the linear sintering shrinkage decreased. In the experimental blocks, the three sectioned pieces of each block showed the different linear shrinkage depending on the area. The tops of the experimental blocks showed the lowest linear sintering shrinkage, whereas the bottoms of the experimental blocks showed the highest linear sintering shrinkage. Within the limitations of this study, the density difference of the presintered zirconia block did not affect the mechanical properties of the sintered zirconia block, but affected the linear sintering shrinkage of the zirconia block.

Sintering behavior and mechanical properties of zirconia compacts fabricated by uniaxial press forming

PubMed Central

Oh, Gye-Jeong; Yun, Kwi-Dug; Lee, Kwang-Min; Lim, Hyun-Pil

2010-01-01

PURPOSE The purpose of this study was to compare the linear sintering behavior of presintered zirconia blocks of various densities. The mechanical properties of the resulting sintered zirconia blocks were then analyzed. MATERIALS AND METHODS Three experimental groups of dental zirconia blocks, with a different presintering density each, were designed in the present study. Kavo Everest® ZS blanks (Kavo, Biberach, Germany) were used as a control group. The experimental group blocks were fabricated from commercial yttria-stabilized tetragonal zirconia powder (KZ-3YF (SD) Type A, KCM. Corporation, Nagoya, Japan). The biaxial flexural strengths, microhardnesses, and microstructures of the sintered blocks were then investigated. The linear sintering shrinkages of blocks were calculated and compared. RESULTS Despite their different presintered densities, the sintered blocks of the control and experimental groups showed similar mechanical properties. However, the sintered block had different linear sintering shrinkage rate depending on the density of the presintered block. As the density of the presintered block increased, the linear sintering shrinkage decreased. In the experimental blocks, the three sectioned pieces of each block showed the different linear shrinkage depending on the area. The tops of the experimental blocks showed the lowest linear sintering shrinkage, whereas the bottoms of the experimental blocks showed the highest linear sintering shrinkage. CONCLUSION Within the limitations of this study, the density difference of the presintered zirconia block did not affect the mechanical properties of the sintered zirconia block, but affected the linear sintering shrinkage of the zirconia block. PMID:21165274

Twenty-four-hour endocrine and metabolic profiles following consumption of high-fructose corn syrup-, sucrose-, fructose-, and glucose-sweetened beverages with meals.

PubMed

Stanhope, Kimber L; Griffen, Steven C; Bair, Brandi R; Swarbrick, Michael M; Keim, Nancy L; Havel, Peter J

2008-05-01

We have reported that, compared with glucose-sweetened beverages, consuming fructose-sweetened beverages with meals results in lower 24-h circulating glucose, insulin, and leptin concentrations and elevated triacylglycerol (TG). However, pure fructose and glucose are not commonly used as sweeteners. High-fructose corn syrup (HFCS) has replaced sucrose as the predominant sweetener in beverages in the United States. We compared the metabolic/endocrine effects of HFCS with sucrose and, in a subset of subjects, with pure fructose and glucose. Thirty-four men and women consumed 3 isocaloric meals with either sucrose- or HFCS-sweetened beverages, and blood samples were collected over 24 h. Eight of the male subjects were also studied when fructose- or glucose-sweetened beverages were consumed. In 34 subjects, 24-h glucose, insulin, leptin, ghrelin, and TG profiles were similar between days that sucrose or HFCS was consumed. Postprandial TG excursions after HFCS or sucrose were larger in men than in women. In the men in whom the effects of 4 sweeteners were compared, the 24-h glucose and insulin responses induced by HFCS and sucrose were intermediate between the lower responses during consumption of fructose and the higher responses during glucose. Unexpectedly, postprandial TG profiles after HFCS or sucrose were not intermediate but comparably high as after pure fructose. Sucrose and HFCS do not have substantially different short-term endocrine/metabolic effects. In male subjects, short-term consumption of sucrose and HFCS resulted in postprandial TG responses comparable to those induced by fructose.

Twenty-four Hour Endocrine and Metabolic Profiles Following Consumption of High Fructose Corn Syrup-, Sucrose- Fructose-, and Glucose-Sweetened Beverages with Meals

PubMed Central

Stanhope, Kimber L.; Griffen, Steven C.; Bair, Brandi R.; Swarbrick, Michael M.; Keim, Nancy L.; Havel, Peter J.

2011-01-01

Background We have reported that compared with glucose-sweetened beverages, consuming fructose-sweetened beverages with meals results in lower 24-h circulating glucose, insulin and leptin concentrations, and elevated triacylglycerol (TG). However, pure fructose and glucose are not commonly used as sweeteners. High fructose corn syrup (HFCS) has replaced sucrose as the predominant sweetener in beverages in the U.S. Objective We compared the metabolic/endocrine effects of HFCS with sucrose, and in a subset of subjects with pure fructose and glucose. Design 34 men and women consumed 3 isocaloric meals with either sucrose- or HFCS-sweetened beverages, and blood samples were collected over 24 hours. Eight of the male subjects were also studied when fructose- or glucose-sweetened beverages were consumed. Results In 34 subjects, 24-h glucose, insulin, leptin, ghrelin and TG profiles were similar between days that sucrose or HFCS were consumed. Postprandial TG excursions after HFCS or sucrose were larger in men than women. In the men in whom the effects of 4 sweeteners were compared, the 24-h glucose and insulin responses induced by HFCS and sucrose were intermediate between the lower responses during consumption of fructose and the higher responses during glucose. Unexpectedly, postprandial TG profiles after HFCS or sucrose were not intermediate, but comparably high as after pure fructose. Conclusions Sucrose and HFCS do not have substantially different short-term endocrine/metabolic effects. In male subjects, short-term consumption of sucrose and HFCS resulted in postprandial TG responses comparable to those induced by fructose. PMID:18469239

Functional Relationship between Sucrose and a Cariogenic Biofilm Formation

PubMed Central

Cai, Jian-Na; Jung, Ji-Eun; Dang, Minh-Huy; Kim, Mi-Ah; Yi, Ho-Keun; Jeon, Jae-Gyu

2016-01-01

Sucrose is an important dietary factor in cariogenic biofilm formation and subsequent initiation of dental caries. This study investigated the functional relationships between sucrose concentration and Streptococcus mutans adherence and biofilm formation. Changes in morphological characteristics of the biofilms with increasing sucrose concentration were also evaluated. S. mutans biofilms were formed on saliva-coated hydroxyapatite discs in culture medium containing 0, 0.05, 0.1, 0.5, 1, 2, 5, 10, 20, or 40% (w/v) sucrose. The adherence (in 4-hour biofilms) and biofilm composition (in 46-hour biofilms) of the biofilms were analyzed using microbiological, biochemical, laser scanning confocal fluorescence microscopic, and scanning electron microscopic methods. To determine the relationships, 2nd order polynomial curve fitting was performed. In this study, the influence of sucrose on bacterial adhesion, biofilm composition (dry weight, bacterial counts, and water-insoluble extracellular polysaccharide (EPS) content), and acidogenicity followed a 2nd order polynomial curve with concentration dependence, and the maximum effective concentrations (MECs) of sucrose ranged from 0.45 to 2.4%. The bacterial and EPS bio-volume and thickness in the biofilms also gradually increased and then decreased as sucrose concentration increased. Furthermore, the size and shape of the micro-colonies of the biofilms depended on the sucrose concentration. Around the MECs, the micro-colonies were bigger and more homogeneous than those at 0 and 40%, and were surrounded by enough EPSs to support their structure. These results suggest that the relationship between sucrose concentration and cariogenic biofilm formation in the oral cavity could be described by a functional relationship. PMID:27275603

Effects of Chloride and Sulfate Salts on the Inhibition or Promotion of Sucrose Crystallization in Initially Amorphous Sucrose-Salt Blends.

PubMed

Thorat, Alpana A; Forny, Laurent; Meunier, Vincent; Taylor, Lynne S; Mauer, Lisa J

2017-12-27

The effects of salts on the stability of amorphous sucrose and its crystallization in different environments were investigated. Chloride (LiCl, NaCl, KCl, MgCl 2 , CaCl 2 , CuCl 2 , FeCl 2 , FeCl 3 , and AlCl 3 ) and sulfate salts with the same cations (Na 2 SO 4 , K 2 SO 4 , MgSO 4 , CuSO 4 , Fe(II)SO 4 , and Fe(III)SO 4 ) were studied. Samples (sucrose controls and sucrose:salt 1:0.1 molar ratios) were lyophilized, stored in controlled temperature and relative humidity (RH) conditions, and monitored for one month using X-ray diffraction. Samples were also analyzed by differential scanning calorimetry, microscopy, and moisture sorption techniques. All lyophiles were initially amorphous, but during storage the presence of a salt had a variable impact on sucrose crystallization. While all samples remained amorphous when stored at 11 and 23% RH at 25 °C, increasing the RH to 33 and 40% RH resulted in variations in crystallization onset times. The recrystallization time generally followed the order monovalent cations < sucrose < divalent cations < trivalent cations. The presence of a salt typically increased water sorption as compared to sucrose alone when stored at the same RH; however, anticrystallization effects were observed for sucrose combined with salts containing di- and trivalent cations in spite of the increased water content. The cation valency and hydration number played a major role in dictating the impact of the added salt on sucrose crystallization.

Role of maltase in the utilization of sucrose by Candida albicans.

PubMed Central

Williamson, P R; Huber, M A; Bennett, J E

1993-01-01

Two isoenzymes of maltase (EC 3.2.1.20) were purified to homogeneity from Candida albicans. Isoenzymes I and II were found to have apparent molecular masses of 63 and 66 kDa on SDS/PAGE with isoelectric points of 5.0 and 4.6 respectively. Both isoenzymes resembled each other in similar N-terminal sequence, specificity for the alpha(1-->4) glycosidic linkage and immune cross-reactivity on Western blots using a maltase II antigen-purified rabbit antibody. Maltase was induced by growth on sucrose whereas beta-fructofuranosidase activity could not be detected under similar conditions. Maltase I and II were shown to be unglycosylated enzymes by neutral sugar assay, and more than 90% of alpha-glucosidase activity was recoverable from spheroplasts. These data, in combination with other results from this laboratory [Geber, Williamson, Rex, Sweeney and Bennett (1992) J. Bacteriol. 174, 6992-6996] showing lack of a plausible leader sequence in genomic or mRNA transcripts, suggest an intracellular localization of the enzyme. To establish further the mechanism of sucrose assimilation by maltase, the existence of a sucrose-inducible H+/sucrose syn-transporter was demonstrated by (1) the kinetics of sucrose-induced [14C]sucrose uptake, (2) recovery of intact [14C]sucrose from ground cells by t.l.c. and (3) transport of 0.83 mol of H+/mol of [14C]sucrose. In total, the above is consistent with a mechanism whereby sucrose is transported into C. albicans to be hydrolysed by an intracellular maltase. Images Figure 1 Figure 2 Figure 4 PMID:8489504

Comparative Sucrose Responsiveness in Apis mellifera and A. cerana Foragers

PubMed Central

Yang, Wenchao; Kuang, Haiou; Wang, Shanshan; Wang, Jie; Liu, Wei; Wu, Zhenhong; Tian, Yuanyuan; Huang, Zachary Y.; Miao, Xiaoqing

2013-01-01

In the European honey bee, Apis mellifera, pollen foragers have a higher sucrose responsiveness than nectar foragers when tested using a proboscis extension response (PER) assay. In addition, Africanized honey bees have a higher sucrose responsiveness than European honey bees. Based on the biology of the Eastern honey bee, A. cerana, we hypothesized that A. cerana should also have a higher responsiveness to sucrose than A. mellifera. To test this hypothesis, we compared the sucrose thresholds of pollen foragers and nectar foragers in both A. cerana and A. mellifera in Fujian Province, China. Pollen foragers were more responsive to sucrose than nectar foragers in both species, consistent with previous studies. However, contrary to our hypothesis, A. mellifera was more responsive than A. cerana. We also demonstrated that this higher sucrose responsiveness in A. mellifera was not due to differences in the colony environment by co-fostering two species of bees in the same mixed-species colonies. Because A. mellifera foragers were more responsive to sucrose, we predicted that their nectar foragers should bring in less concentrated nectar compared to that of A. cerana. However, we found no differences between the two species. We conclude that A. cerana shows a different pattern in sucrose responsiveness from that of Africanized bees. There may be other mechanisms that enable A. cerana to perform well in areas with sparse nectar resources. PMID:24194958

Increased sink strength offsets the inhibitory effect of sucrose on sugarcane photosynthesis.

PubMed

Ribeiro, Rafael V; Machado, Eduardo C; Magalhães Filho, José R; Lobo, Ana Karla M; Martins, Márcio O; Silveira, Joaquim A G; Yin, Xinyou; Struik, Paul C

2017-01-01

Spraying sucrose inhibits photosynthesis by impairing Rubisco activity and stomatal conductance (g s ), whereas increasing sink demand by partially darkening the plant stimulates sugarcane photosynthesis. We hypothesized that the stimulatory effect of darkness can offset the inhibitory effect of exogenous sucrose on photosynthesis. Source-sink relationship was perturbed in two sugarcane cultivars by imposing partial darkness, spraying a sucrose solution (50mM) and their combination. Five days after the onset of the treatments, the maximum Rubisco carboxylation rate (V cmax ) and the initial slope of A-C i curve (k) were estimated by measuring leaf gas exchange and chlorophyll fluorescence. Photosynthesis was inhibited by sucrose spraying in both genotypes, through decreases in V cmax , k, g s and ATP production driven by electron transport (J atp ). Photosynthesis of plants subjected to the combination of partial darkness and sucrose spraying was similar to photosynthesis of reference plants for both genotypes. Significant increases in V cmax , g s and J atp and marginal increases in k were noticed when combining partial darkness and sucrose spraying compared with sucrose spraying alone. Our data also revealed that increases in sink strength due to partial darkness offset the inhibition of sugarcane photosynthesis caused by sucrose spraying, enhancing the knowledge on endogenous regulation of sugarcane photosynthesis through the source-sink relationship. Copyright © 2016 Elsevier GmbH. All rights reserved.

Chronic sucrose intake decreases concentrations of n6 fatty acids, but not docosahexaenoic acid in the rat brain phospholipids.

PubMed

Mašek, Tomislav; Starčević, Kristina

2017-07-13

We investigated the influence of high sucrose intake, administered in drinking water, on the lipid profile of the brain and on the expression of SREBP1c and Δ-desaturase genes. Adult male rats received 30% sucrose solution for 20 weeks (Sucrose group), or plain water (Control group). After the 20th week of sucrose treatment, the Sucrose group showed permanent hyperglycemia. Sucrose treatment also increased the amount of total lipids and fatty acids in the brain. The brain fatty acid profile of total lipids as well as phosphatidylethanolamine, phosphatidylcholine and cardiolipin of the Sucrose group was extensively changed. The most interesting change was a significant decrease in n6 fatty acids, including the important arachidonic acid, whereas the content of oleic and docosahexaenoic acid remained unchanged. RT-qPCR revealed an increase in Δ-5-desaturase and SREBP1c gene expression. In conclusion, high sucrose intake via drinking water extensively changes rat brain fatty acid profile by decreasing n6 fatty acids, including arachidonic acid. In contrast, the content of docosahexaenoic acid remains constant in the brain total lipids as well as in phospholipids. Changes in the brain fatty acid profile reflect changes in the lipid metabolism of the rat lipogenic tissues and concentrations in the circulation. Copyright © 2017 Elsevier B.V. All rights reserved.

[Effect of exogenous sucrose on growth and active ingredient content of licorice seedlings under salt stress conditions].

PubMed

Liu, Fu-zhi; Yang, Jun

2015-11-01

Licorice seedlings were taken as experimental materials, an experiment was conducted to study the effects of exogenous sucrose on growth and active ingredient content of licorice seedlings under NaCl stress conditions. The results of this study showed that under salt stress conditions, after adding a certain concentration of exogenous sucrose, the licorice seedlings day of relative growth rate was increasing, and this stress can be a significant weakening effect, indicating that exogenous sucrose salt stress-relieving effect. The total flavonoids and phenylalanine ammonia lyase (PAL) activity were significantly increased, the exogenous sucrose can mitigated the seedling roots under salt stress, the licorice flavonoid content in the enhanced growth was largely due to the activity of PAL an increased, when the concentration of exogenous sucrose wae 10 mmol x L(-1), PAL activity reaching a maximum, when the concentration of exogenous sucrose was 15 mmol x L(-1), PAL activity turned into a downward trend, the results indicating that this mitigation has concentration effect. After applying different concentrations of exogenous sugar, the contents of liquiritin changes with the change of flavonoids content was similar. After applying different concentrations of exogenous sucrose, the content of licorice acid under salt stress was higher than the levels were not reached during salt stress, the impact of exogenous sucrose concentration gradient of licorice acid accumulation was not obvious.

Trans-generational desensitization and within-generational resensitization of a sucrose-best neuron in the polyphagous herbivore Helicoverpa armigera (Lepidoptera: Noctuidae)

PubMed Central

Ma, Ying; Li, Jingjing; Tang, Qingbo; Zhang, Xuening; Zhao, Xincheng; Yan, Fengming; van Loon, Joop J. A.

2016-01-01

Dietary exposure of insects to a feeding deterrent substance for hours to days can induce habituation and concomitant desensitization of the response of peripheral gustatory neurons to such a substance. In the present study, larvae of the herbivore Helicoverpa armigera were fed on diets containing either a high, medium or low concentration of sucrose, a major feeding stimulant. The responsiveness of the sucrose-best neuron in the lateral sensilla styloconica on the galea was quantified. Results showed the response of the sucrose-best neuron exposed to high-sucrose diets decreased gradually over successive generations, resulting in complete desensitization in the 5th and subsequent generations. However, the sensitivity was completely restored in the ninth generation after neonate larvae were exposed to low-sucrose diet. These findings demonstrate phenotypic plasticity and exclude inadvertent artificial selection for low sensitivity to sucrose. No significant changes were found in the sensitivity of caterpillars which experienced low- or medium-sucrose diets over the same generations. Such desensitization versus re-sensitization did not generalise to the phagosimulant myo-inositol-sensitive neuron or the feeding deterrent-sensitive neuron. Our results demonstrate that under conditions of high sucrose availability trans-generational desensitization of a neuron sensitive to this feeding stimulant becomes more pronounced whereas re-sensitization occurs within one generation. PMID:27966640

Water–solid interactions in amorphous maltodextrin-crystalline sucrose binary mixtures

PubMed Central

Ghorab, Mohamed K.; Toth, Scott J.; Simpson, Garth J.; Mauer, Lisa J.; Taylor, Lynne S.

2016-01-01

Amorphous and crystalline solids are commonly found together in a variety of pharmaceutical and food products. In this study, the influence of co-formulation of amorphous maltodextrins (MDs) and crystalline sucrose (S) on moisture sorption, deliquescence, and glass transition (Tg) properties of powder blends was investigated. Individual components and binary mixtures of four different molecular weight MDs with sucrose in 1:1 w/w ratios were exposed to various relative humidity (RH) environments and their equilibrium and dynamic moisture contents were monitored. The deliquescence point (RH0) and dissolution behavior of sucrose alone and in blends was also monitored by polarized light microscopy and second harmonic generation imaging. In S:MD blends, the deliquescence RH of sucrose was lower than the RH0 of sucrose alone, and synergistic moisture sorption also occurred at RHs lower than the RH0. Intimate contact of sucrose crystals with the amorphous MDs resulted in complete dissolution of sucrose at RH < RH0. When blends were stored at conditions exceeding the Tg of the individual MDs (25 °C and 60%, 49% and 34%RH for MD21, MD29 and MD40, respectively), the Tg of the blends was lower than that of individual MDs. Thus, co-formulation of amorphous MDs with crystalline sucrose sensitizes the blend to moisture, potentially leading to deleterious changes in the formulation if storage conditions are not adequately controlled. PMID:23477494

The non-metabolizable sucrose analog sucralose is a potent inhibitor of hormogonium differentiation in the filamentous cyanobacterium Nostoc punctiforme.

PubMed

Splitt, Samantha D; Risser, Douglas D

2016-03-01

Nostoc punctiforme is a filamentous cyanobacterium which forms nitrogen-fixing symbioses with several different plants and fungi. Establishment of these symbioses requires the formation of motile hormogonium filaments. Once infected, the plant partner is thought to supply a hormogonium-repressing factor (HRF) to maintain the cyanobacteria in a vegetative, nitrogen-fixing state. Evidence implies that sucrose may serve as a HRF. Here, we tested the effects of sucralose, a non-metabolizable sucrose analog, on hormogonium differentiation. Sucralose inhibited hormogonium differentiation at a concentration approximately one-tenth that of sucrose. This result implies that: (1) sucrose, not a sucrose catabolite, is perceived by the cell and (2) inhibition is not due to a more general osmolarity-dependent effect. Additionally, both sucrose and sucralose induced the accrual of a polysaccharide sheath which bound specifically to the lectin ConA, indicating the presence of α-D-mannose and/or α-D-glucose. A ConA-specific polysaccharide was also found to be expressed in N. punctiforme colonies from tissue sections of the symbiotically grown hornwort Anthoceros punctatus. These findings imply that plant-derived sucrose or sucrose analogs may have multiple effects on N. punctiforme, including both repression of hormogonia and the induction of a polysaccharide sheath that may be essential to establish and maintain the symbiotic state.

Vegetative and reproductive growth of salt-stressed chickpea are carbon-limited: sucrose infusion at the reproductive stage improves salt tolerance

PubMed Central

Khan, Hammad A.; Siddique, Kadambot H.M.

2017-01-01

Abstract Reproductive processes of chickpea (Cicer arietinum L.) are particularly sensitive to salinity. We tested whether limited photoassimilate availability contributes to reproductive failure in salt-stressed chickpea. Rupali, a salt-sensitive genotype, was grown in aerated nutrient solution, either with non-saline (control) or 30mM NaCl treatment. At flowering, stems were either infused with sucrose solution (0.44M), water only or maintained without any infusion, for 75 d. The sucrose and water infusion treatments of non-saline plants had no effect on growth or yield, but photosynthesis declined in response to sucrose infusion. Salt stress reduced photosynthesis, decreased tissue sugars by 22–47%, and vegetative and reproductive growth were severely impaired. Sucrose infusion of salt-treated plants increased total sugars in stems, leaves and developing pods, to levels similar to those of non-saline plants. In salt-stressed plants, sucrose infusion increased dry mass (2.6-fold), pod numbers (3.8-fold), seed numbers (6.5-fold) and seed yield (10.4-fold), yet vegetative growth and reproductive failure were not rescued completely by sucrose infusion. Sucrose infusion partly rescued reproductive failure in chickpea by increasing vegetative growth enabling more flower production and by providing sucrose for pod and seed growth. We conclude that insufficient assimilate availability limits yield in salt-stressed chickpea. PMID:27140441

Lipogenesis and lipid peroxidation in rat testes after long-term treatment with sucrose and tannic acid in drinking water.

PubMed

Mašek, T; Starčević, K

2017-05-01

We studied the influence of long-term treatment with sucrose and tannic acid in drinking water on the fatty acid profile and lipid peroxidation in rat testes. Male Wistar rats were supplemented with sucrose (30% w/v) or with sucrose and tannic acid (sucrose 30% w/v, tannic acid 0.1% w/v) in drinking water. The treatment with sucrose elevated blood glucose levels in the plasma (p < .05) and decreased the testis weight (p < .05) and testis index (p < .05) of the rats. Sucrose treatment increased monounsaturated fatty acids (MUFA) and C22:6n3, and decreased n6 fatty acids in testis tissue. Lipid peroxidation was significantly increased after sucrose administration in plasma (p < .05) and testis tissue (p < .01). The addition of tannic acid led to the decrease in lipid peroxidation in the plasma (p < .05) and testis (p < .05), a further increase in MUFA and decrease in n6 fatty acids. In conclusion, sucrose significantly altered the testis fatty acid profile with an increase in MUFA and C22:6n3, and a decrease in n6 fatty acids. Tannic acid attenuated oxidative stress and hyperglycaemia, but it did not improve pathological changes in the fatty acid composition of the testis. © 2016 Blackwell Verlag GmbH.

Comparative sucrose responsiveness in Apis mellifera and A. cerana foragers.

PubMed

Yang, Wenchao; Kuang, Haiou; Wang, Shanshan; Wang, Jie; Liu, Wei; Wu, Zhenhong; Tian, Yuanyuan; Huang, Zachary Y; Miao, Xiaoqing

2013-01-01

In the European honey bee, Apis mellifera, pollen foragers have a higher sucrose responsiveness than nectar foragers when tested using a proboscis extension response (PER) assay. In addition, Africanized honey bees have a higher sucrose responsiveness than European honey bees. Based on the biology of the Eastern honey bee, A. cerana, we hypothesized that A. cerana should also have a higher responsiveness to sucrose than A. mellifera. To test this hypothesis, we compared the sucrose thresholds of pollen foragers and nectar foragers in both A. cerana and A. mellifera in Fujian Province, China. Pollen foragers were more responsive to sucrose than nectar foragers in both species, consistent with previous studies. However, contrary to our hypothesis, A. mellifera was more responsive than A. cerana. We also demonstrated that this higher sucrose responsiveness in A. mellifera was not due to differences in the colony environment by co-fostering two species of bees in the same mixed-species colonies. Because A. mellifera foragers were more responsive to sucrose, we predicted that their nectar foragers should bring in less concentrated nectar compared to that of A. cerana. However, we found no differences between the two species. We conclude that A. cerana shows a different pattern in sucrose responsiveness from that of Africanized bees. There may be other mechanisms that enable A. cerana to perform well in areas with sparse nectar resources.

Reinforcement Value and Substitutability of Sucrose and Wheel Running: Implications for Activity Anorexia

ERIC Educational Resources Information Center

Belke, Terry W.; Duncan, Ian D.; Pierce, W. David

2006-01-01

Choice between sucrose and wheel-running reinforcement was assessed in two experiments. In the first experiment, ten male Wistar rats were exposed to concurrent VI 30 s VI 30 s schedules of wheel-running and sucrose reinforcement. Sucrose concentration varied across concentrations of 2.5, 7.5, and 12.5%. As concentration increased, more behavior…

A density matrix-based method for the linear-scaling calculation of dynamic second- and third-order properties at the Hartree-Fock and Kohn-Sham density functional theory levels.

PubMed

Kussmann, Jörg; Ochsenfeld, Christian

2007-11-28

A density matrix-based time-dependent self-consistent field (D-TDSCF) method for the calculation of dynamic polarizabilities and first hyperpolarizabilities using the Hartree-Fock and Kohn-Sham density functional theory approaches is presented. The D-TDSCF method allows us to reduce the asymptotic scaling behavior of the computational effort from cubic to linear for systems with a nonvanishing band gap. The linear scaling is achieved by combining a density matrix-based reformulation of the TDSCF equations with linear-scaling schemes for the formation of Fock- or Kohn-Sham-type matrices. In our reformulation only potentially linear-scaling matrices enter the formulation and efficient sparse algebra routines can be employed. Furthermore, the corresponding formulas for the first hyperpolarizabilities are given in terms of zeroth- and first-order one-particle reduced density matrices according to Wigner's (2n+1) rule. The scaling behavior of our method is illustrated for first exemplary calculations with systems of up to 1011 atoms and 8899 basis functions.

Improved production of isomaltulose by a newly isolated mutant of Serratia sp. cells immobilized in calcium alginate.

PubMed

Kim, Yonghwan; Koo, Bong-Seong; Lee, Hyeon-Cheol; Yoon, Youngdae

2015-03-01

Isomaltulose, also known as palatinose, is produced by sucrose isomerase and has been highlighted as a sugar substitute due to a number of advantageous properties. For the massive production of isomaltulose, high resistance to sucrose and stability of sucrose isomerase as well as sucrose conversion yields would be critical factors. We describe a series of screening procedures to isolate the mutant strain of Serratia sp. possessing enhanced isomaltulose production with improved stability. The new Serratia sp. isolated from a series of screening procedures allowed us to produce isomaltulose from 60% sucrose solution, with over 90% conversion yield. Moreover, when this strain was immobilized in calcium alginate beads and placed in a medium containing 60% sucrose, it showed over 70% sucrose conversion yields for 30 cycles of repeated-batch reactions. Thus, improved conversion activity and stability of the newly isolated Serratia sp. strain in the present study would be highly valuable for industries related to isomaltulose production.

Linear stability analysis of the Vlasov-Poisson equations in high density plasmas in the presence of crossed fields and density gradients

NASA Technical Reports Server (NTRS)

Kaup, D. J.; Hansen, P. J.; Choudhury, S. Roy; Thomas, Gary E.

1986-01-01

The equations for the single-particle orbits in a nonneutral high density plasma in the presence of inhomogeneous crossed fields are obtained. Using these orbits, the linearized Vlasov equation is solved as an expansion in the orbital radii in the presence of inhomogeneities and density gradients. A model distribution function is introduced whose cold-fluid limit is exactly the same as that used in many previous studies of the cold-fluid equations. This model function is used to reduce the linearized Vlasov-Poisson equations to a second-order ordinary differential equation for the linearized electrostatic potential whose eigenvalue is the perturbation frequency.

Photocatalytic properties of hierarchical ZnO flowers synthesized by a sucrose-assisted hydrothermal method

NASA Astrophysics Data System (ADS)

Lv, Wei; Wei, Bo; Xu, Lingling; Zhao, Yan; Gao, Hong; Liu, Jia

2012-10-01

In this work, hierarchical ZnO flowers were synthesized via a sucrose-assisted urea hydrothermal method. The thermogravimetric analysis/differential thermal analysis (TGA-DTA) and Fourier transform infrared spectra (FTIR) showed that sucrose acted as a complexing agent in the synthesis process and assisted combustion during annealing. Photocatalytic activity was evaluated using the degradation of organic dye methyl orange. The sucrose added ZnO flowers showed improved activity, which was mainly attributed to the better crystallinity as confirmed by X-ray photoelectron spectroscopy (XPS) analysis. The effect of sucrose amount on photocatalytic activity was also studied.

Population response to climate change: linear vs. non-linear modeling approaches.

PubMed

Ellis, Alicia M; Post, Eric

2004-03-31

Research on the ecological consequences of global climate change has elicited a growing interest in the use of time series analysis to investigate population dynamics in a changing climate. Here, we compare linear and non-linear models describing the contribution of climate to the density fluctuations of the population of wolves on Isle Royale, Michigan from 1959 to 1999. The non-linear self excitatory threshold autoregressive (SETAR) model revealed that, due to differences in the strength and nature of density dependence, relatively small and large populations may be differentially affected by future changes in climate. Both linear and non-linear models predict a decrease in the population of wolves with predicted changes in climate. Because specific predictions differed between linear and non-linear models, our study highlights the importance of using non-linear methods that allow the detection of non-linearity in the strength and nature of density dependence. Failure to adopt a non-linear approach to modelling population response to climate change, either exclusively or in addition to linear approaches, may compromise efforts to quantify ecological consequences of future warming.

Consumption of baked nuts or seeds reduces dental plaque acidogenicity after sucrose challenge.

PubMed

Wang, Xiaoling; Cheng, Chuoyue; Ge, Chunling; Wang, Bing; Gan, Ye-Hua

2016-06-01

To assess the acidogenic potential of eight different types of baked nuts or seeds eaten alone and after a sucrose challenge using in-dwelling electrode telemetry. Six participants wearing a mandibular partial prosthesis incorporated with a miniature glass pH electrode were enrolled. The plaque pH was measured after 5 or 6 days of plaque accumulation. To establish a control, the subjects were instructed to rinse with sucrose, without any subsequent treatment, at the first visit. At each subsequent test visit, the subjects were asked to chew sugar free xylitol gum or consume 10 g of baked (180 degrees C, 5 minutes) peanuts, walnuts, pistachios, cashews, almonds, sunflower seeds, pumpkin seeds, or watermelon seeds alone and 10 minutes after a sucrose rinse. The minimum plaque pH value and area of plaque pH curve under 5.7 (AUC5.7) during and after nut/seed consumption or gum chewing alone, the plaque pH value at 10 minutes after the sucrose rinse, the time required for the pH to return to >5.7 and AUC5.7 after the sucrose rinse with or without nut/seed consumption or gum chewing were calculated from the telemetric curves. The sucrose rinse induced a rapid decrease in the plaque pH to 4.32 +/- 0.17 at 10 minutes; this value remained below 5.7 for the measurement period. The AUC5.7 values were 34.58 +/- 7.27 and 63.55 +/- 15.17 for 40 and 60 minutes after the sucrose challenge, respectively. With the exception of cashews and pumpkin seeds (minimum pH, 5.42 and 5.63 respectively), the nuts or seeds did not decrease the plaque pH to below 5.7 when consumed alone, with the AUC5.7 values during and after consumption (total 40 minutes) ranging from 0.24 to 2.5 (8.44 for cashews), which were significantly lower than those after the sucrose challenge. Furthermore, nut/seed consumption or gum chewing after the sucrose challenge significantly reversed the sucrose-induced decrease in the plaque pH, and the time required for the pH to return to >5.7 and the AUC5.7 values for 60 minutes after the sucrose challenge were much less than that of the sucrose challenge without subsequent interference.

The Purification and Concentration of Hog Cholera Virus*

PubMed Central

Cunliffe, H. R.; Rebers, P. A.

1968-01-01

Partial purification of hog cholera virus (HCV) using a simple batch-type chromatographic procedure with magnetic ferric oxide (MFO) is described. Infectious HCV was adsorbed from isotonic solutions to MFO and was eluted under conditions of low ionic strength and high pH. Aqueous solutions of 0.01 M sodium cyanide or 0.0003 M ammonium hydroxide effectively dissociated MFO-HCV complexes. The data indicate that 50 to 100% of the original HCV infectivity was recovered concomitant with a 90 to 95% reduction of extraneous organic nitrogen. MFO-purified HCV was concentrated by density gradient type centrifugations in buffered solutions of cesium chloride and sucrose. Prolonged isodensity centrifugations of concentrated MFO-purified HCV indicated a buoyant density of 1.14 to 1.15 gm/ml for the strain of virus used. PMID:15846899

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kim, N.S.K.

In aqueous lysine-sucrose model systems, the effects of reaction time, pH and molar ratio were studied on the formation of non-enzymatic browning reaction (NBR) products. The extent of sucrose hydrolysis was measured and the antioxidant effect of NBR products on linoleic acid emulsions was examined. Nuclear magnetic resonance (NMR) spectra were obtained at various stages of browning. Sucrose produced NMR produces with lysine in an aqueous system at 100/sup 0/C. The C-13 NMR spectra indicated that the NBR started when sucrose and lysine were dissolved in water. The C-13 NMR spectra also showed that heating did not have an effectmore » on the gross composition of polymeric species. The absorbance at 480 nm of 0.75 M lysine-sucrose solution heated up to 6 hours increased with reaction times. The pH values of heated lysine-sucrose solution gradually decreased with reaction time. When 0.75 M sucrose or lysine solution was heated separately up to 6 hours, there were no changes in absorbance in pH. In the pH range of 3.52-6.35, higher absorbance was obtained from heated lysine-sucrose solution at acidic pH levels than at neutral pH levels. As the concentration of lysine and sucrose solution was increased, the absorbance increased. At longer reaction times or acidic pH levels, enhanced hydrolysis of sucrose to reducing sugars resulted in more NBR products. NBR products obtained at a longer reaction time, an acidic pH, and higher concentration of reactants showed a darker brown color and were effective in preventing the formation of peroxides. The oxygen uptake of linoleic acid emulsion having NBR products was smaller than that of linoleic acid emulsion without NBR products. Based on these results, it was concluded that sucrose may act as an antioxidant in processed foods containing both amino acids and lipids.« less

Effect of Diets Containing Sucrose vs. D-tagatose in Hypercholesterolemic Mice

DOE Office of Scientific and Technical Information (OSTI.GOV)

Police, S.; Harris, J; Lodder, R

Effects of functional sweeteners on the development of the metabolic syndrome and atherosclerosis are unknown. The objective was to compare the effect of dietary carbohydrate in the form of sucrose (SUCR) to D-tagatose (TAG; an isomer of fructose currently used as a low-calorie sweetener) on body weight, blood cholesterol concentrations, hyperglycemia, and atherosclerosis in low-density lipoprotein receptor deficient (LDLr-/-) mice. LDLr-/- male and female mice were fed either standard murine diet or a diet enriched with TAG or SUCR as carbohydrate sources for 16 weeks. TAG and SUCR diets contained equivalent amounts (g/kg) of protein, fat, and carbohydrate. We measuredmore » food intake, body weight, adipocyte diameter, serum cholesterol and lipoprotein concentrations, and aortic atherosclerosis. Macrophage immunostaining and collagen content were examined in aortic root lesions. CONTROL and TAG-fed mice exhibited similar energy intake, body weights and blood glucose and insulin concentrations, but SUCR-fed mice exhibited increased energy intake and became obese and hyperglycemic. Adipocyte diameter increased in female SUCR-fed mice compared to TAG and CONTROL. Male and female SUCR-fed mice had increased serum cholesterol and triglyceride concentrations compared to TAG and CONTROL. Atherosclerosis was increased in SUCR-fed mice of both genders compared to TAG and CONTROL. Lesions from SUCR-fed mice exhibited pronounced macrophage immunostaining and reductions in collagen content compared to TAG and CONTROL mice. These results demonstrate that in comparison to sucrose, equivalent substitution of TAG as dietary carbohydrate does not result in the same extent of obesity, hyperglycemia, hyperlipidemia, and atherosclerosis.« less

Doped tricalcium phosphate bone tissue engineering scaffolds using sucrose as template and microwave sintering: enhancement of mechanical and biological properties.

PubMed

Ke, Dongxu; Bose, Susmita

2017-09-01

β-tricalcium phosphate (β-TCP) is a widely used biocompatible ceramic in orthopedic and dental applications. However, its osteoinductivity and mechanical properties still require improvements. In this study, porous β-TCP and MgO/ZnO-TCP scaffolds were prepared by the thermal decomposition of sucrose. Crack-free cylindrical scaffolds could only be prepared with the addition of MgO and ZnO due to their stabilization effects. Porous MgO/ZnO-TCP scaffolds with a density of 61.39±0.66%, an estimated pore size of 200μm and a compressive strength of 24.96±3.07MPa were prepared by using 25wt% sucrose after conventional sintering at 1250°C. Microwave sintering further increased the compressive strength to 37.94±6.70MPa, but it decreased the open interconnected porosity to 8.74±1.38%. In addition, the incorporation of polycaprolactone (PCL) increased 22.36±3.22% of toughness while maintaining its compressive strength at 25.45±2.21MPa. Human osteoblast cell line was seeded on scaffolds to evaluate the effects of MgO/ZnO and PCL on the biological property of β-TCP in vitro. Both MgO/ZnO and PCL improved osteoinductivity of β-TCP. PCL also decreased osteoblastic apoptosis due to its particular surface chemistry. This novel porous MgO/ZnO-TCP scaffold with PCL shows improved mechanical and biological properties, which has great potential in bone tissue engineering applications. Copyright © 2017. Published by Elsevier B.V.

Effect of Diets Containing Sucrose vs. D-tagatose in Hypercholesterolemic Mice

PubMed Central

Police, Sara B.; Harris, J. Clay; Lodder, Robert A.; Cassis, Lisa A.

2010-01-01

Effects of functional sweeteners on the development of the metabolic syndrome and atherosclerosis are unknown. The objective was to compare the effect of dietary carbohydrate in the form of sucrose (SUCR) to D-tagatose (TAG; an isomer of fructose currently used as a low-calorie sweetener) on body weight, blood cholesterol concentrations, hyperglycemia, and atherosclerosis in low-density lipoprotein receptor deficient (LDLr−/−) mice. LDLr−/− male and female mice were fed either standard murine diet or a diet enriched with TAG or SUCR as carbohydrate sources for 16 weeks. TAG and SUCR diets contained equivalent amounts (g/kg) of protein, fat, and carbohydrate. We measured food intake, body weight, adipocyte diameter, serum cholesterol and lipoprotein concentrations, and aortic atherosclerosis. Macrophage immunostaining and collagen content were examined in aortic root lesions. CONTROL and TAG-fed mice exhibited similar energy intake, body weights and blood glucose and insulin concentrations, but SUCR-fed mice exhibited increased energy intake and became obese and hyperglycemic. Adipocyte diameter increased in female SUCR-fed mice compared to TAG and CONTROL. Male and female SUCR-fed mice had increased serum cholesterol and triglyceride concentrations compared to TAG and CONTROL. Atherosclerosis was increased in SUCR-fed mice of both genders compared to TAG and CONTROL. Lesions from SUCR-fed mice exhibited pronounced macrophage immunostaining and reductions in collagen content compared to TAG and CONTROL mice. These results demonstrate that in comparison to sucrose, equivalent substitution of TAG as dietary carbohydrate does not result in the same extent of obesity, hyperglycemia, hyperlipidemia, and atherosclerosis. PMID:19008872

Effect of diets containing sucrose vs. D-tagatose in hypercholesterolemic mice.

PubMed

Police, Sara B; Harris, J Clay; Lodder, Robert A; Cassis, Lisa A

2009-02-01

Effects of functional sweeteners on the development of the metabolic syndrome and atherosclerosis are unknown. The objective was to compare the effect of dietary carbohydrate in the form of sucrose (SUCR) to D-tagatose (TAG; an isomer of fructose currently used as a low-calorie sweetener) on body weight, blood cholesterol concentrations, hyperglycemia, and atherosclerosis in low-density lipoprotein receptor deficient (LDLr(-/-)) mice. LDLr(-/-) male and female mice were fed either standard murine diet or a diet enriched with TAG or SUCR as carbohydrate sources for 16 weeks. TAG and SUCR diets contained equivalent amounts (g/kg) of protein, fat, and carbohydrate. We measured food intake, body weight, adipocyte diameter, serum cholesterol and lipoprotein concentrations, and aortic atherosclerosis. Macrophage immunostaining and collagen content were examined in aortic root lesions. CONTROL and TAG-fed mice exhibited similar energy intake, body weights and blood glucose and insulin concentrations, but SUCR-fed mice exhibited increased energy intake and became obese and hyperglycemic. Adipocyte diameter increased in female SUCR-fed mice compared to TAG and CONTROL. Male and female SUCR-fed mice had increased serum cholesterol and triglyceride concentrations compared to TAG and CONTROL. Atherosclerosis was increased in SUCR-fed mice of both genders compared to TAG and CONTROL. Lesions from SUCR-fed mice exhibited pronounced macrophage immunostaining and reductions in collagen content compared to TAG and CONTROL mice. These results demonstrate that in comparison to sucrose, equivalent substitution of TAG as dietary carbohydrate does not result in the same extent of obesity, hyperglycemia, hyperlipidemia, and atherosclerosis.

Effect of a long-term exposure to concentrated sucrose and maltodextrin solutions on the preference, appetence, feed intake and growth performance of post-weaned piglets.

PubMed

Guzmán-Pino, Sergio A; Solà-Oriol, David; Figueroa, Jaime; Dwyer, Dominic M; Pérez, José F

2015-03-15

Commercial pigs display an innate attraction for sweet taste compounds. However, the impact of long-term availability to supplementary carbohydrate solutions on their general feeding behavior has not been examined. In this work we assess the effect of 12-days exposure to 16% sucrose and 16% maltodextrin solutions on the feed intake and growth performance of piglets, and on their preference and appetence for sweet or protein solutions. The innate preference of piglets was assessed by an initial choice test between 2% sucrose and 2% animal plasma solutions for a period of three minutes. Piglets showed higher intake and preference for 2% sucrose than for 2% animal plasma. In Experiment 1, piglets were then free-offered a 16% sucrose solution as a supplement to the diet, showing a higher intake of it than water and a reduction in feed intake and weight gain. A similar situation occurred during the last days of free-exposure to a 16% maltodextrin solution in Experiment 2. The choice test between 2% sucrose and 2% animal plasma solution was repeated after the exposure to the concentrated solutions. In both experiments, a reduction in the initial preference for 2% sucrose was observed. Similarly, piglets that had previous access to the 16% sucrose and 16% maltodextrin solutions showed a decrease in the appetence for 2% sucrose in comparison with that for 2% animal plasma, as measured by a one-pan test at the end of the experiments. It is concluded that long-term exposure to concentrated sucrose and maltodextrin solutions reduces feed intake and growth in weanling piglets, and also reverses their innate preference and appetence for dilute sweet over protein solutions. Copyright © 2015 Elsevier Inc. All rights reserved.

Sucrose-Metabolizing Enzymes in Transport Tissues and Adjacent Sink Structures in Developing Citrus Fruit 1

PubMed Central

Lowell, Cadance A.; Tomlinson, Patricia T.; Koch, Karen E.

1989-01-01

Juice tissues of citrus lack phloem; therefore, photosynthates enroute to juice sacs exit the vascular system on the surface of each segment. Areas of extensive phloem unloading and transport (vascular bundles + segment epidermis) can thus be separated from those of assimilate storage (juice sacs) and adjacent tissues where both processes occur (peel). Sugar composition, dry weight accumulation, and activities of four sucrose-metabolizing enzymes (soluble and cell-wall-bound acid invertase, alkaline invertase, sucrose synthase, and sucrose phosphate synthase) were measured in these transport and sink tissues of grapefruit (Citrus paradisi Macf.) to determine more clearly whether a given enzyme appeared to be more directly associated with assimilate transport versus deposition or utilization. Results were compared at three developmental stages. Activity of sucrose (per gram fresh weight and per milligram protein) extracted from zones of extensive phloem unloading and transport was significantly greater than from adjacent sink tissues during the stages (II and III) when juice sacs grow most rapidly. In stage II fruit, activity of sucrose synthase also significantly surpassed that of all other sucrose-metabolizing enzymes in extracts from the transport tissues (vascular bundles + segment epidermis). In contrast, sucrose phosphate synthase and alkaline invertase at this stage of growth were the most active enzymes from adjacent, rapidly growing, phloem-free sink tissues (juice sacs). Activity of these two enzymes in extracts from juice sacs was significantly greater than that form the transport tissues (vascular bundles + segment epidermis). Soluble acid invertase was the most active enzyme in extracts from all tissues of very young fruit (stage I), including nonvascular regions, but nearly disappeared prior to the onset of juice sac sugar accumulation. The physiological function of high sucrose synthase activity in the transport tissues during rapid sucrose import remains to be determined. PMID:16666942

Chronic high-sucrose diet increases fibroblast growth factor 21 production and energy expenditure in mice.

PubMed

Maekawa, Ryuya; Seino, Yusuke; Ogata, Hidetada; Murase, Masatoshi; Iida, Atsushi; Hosokawa, Kaori; Joo, Erina; Harada, Norio; Tsunekawa, Shin; Hamada, Yoji; Oiso, Yutaka; Inagaki, Nobuya; Hayashi, Yoshitaka; Arima, Hiroshi

2017-11-01

Excess carbohydrate intake causes obesity in humans. On the other hand, acute administration of fructose, glucose or sucrose in experimental animals has been shown to increase the plasma concentration of anti-obesity hormones such as glucagon-like peptide 1 (GLP-1) and Fibroblast growth factor 21 (FGF21), which contribute to reducing body weight. However, the secretion and action of GLP-1 and FGF21 in mice chronically fed a high-sucrose diet has not been investigated. To address the role of anti-obesity hormones in response to increased sucrose intake, we analyzed mice fed a high-sucrose diet, a high-starch diet or a normal diet for 15 weeks. Mice fed a high-sucrose diet showed resistance to body weight gain, in comparison with mice fed a high-starch diet or control diet, due to increased energy expenditure. Plasma FGF21 levels were highest among the three groups in mice fed a high-sucrose diet, whereas no significant difference in GLP-1 levels was observed. Expression levels of uncoupling protein 1 (UCP-1), FGF receptor 1c (FGFR1c) and β-klotho (KLB) mRNA in brown adipose tissue were significantly increased in high sucrose-fed mice, suggesting increases in FGF21 sensitivity and energy expenditure. Expression of carbohydrate responsive element binding protein (ChREBP) mRNA in liver and brown adipose tissue was also increased in high sucrose-fed mice. These results indicate that FGF21 production in liver and brown adipose tissue is increased in high-sucrose diet and participates in resistance to weight gain. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

The effect of early-life stress and chronic high-sucrose diet on metabolic outcomes in female rats.

PubMed

Maniam, Jayanthi; Antoniadis, Christopher P; Morris, Margaret J

2015-01-01

Early-life stress affects metabolic outcomes and choice of diet influences the development of metabolic disease. Here we tested the hypothesis that chronic sugar intake exacerbates metabolic deficits induced by early-life stress. Early-life stress was induced in Sprague-Dawley rats using limited nesting material in early lactation (LN, postnatal days 2-9), and siblings were given chow alone or with additional sucrose post weaning (n = 9-17 per group). Female control and LN siblings had unlimited access to either chow plus water, or chow and water plus 25% sucrose solution (Sucrose), from 3-15 weeks of age. Weekly body weight and food intake were measured. Glucose and insulin tolerance were tested at 13 and 14 weeks of age, respectively. Rats were killed at 15 weeks. Hepatic triglyceride and markers of lipid synthesis - fatty acid synthase, acetyl-CoA carboxylase alpha and oxidation - and peroxisome proliferator-activated receptor gamma coactivator 1-alpha (Pgc-1α) were examined. Mediators of hepatic glucocorticoid metabolism, specifically 11-beta hydroxysteroid dehydrogenase-1 (11βHSD-1), 5-α reductase, and glucocorticoid and mineralocorticoid receptor mRNAs were also measured. Sucrose increased caloric intake in both groups, but overall energy intake was not altered by LN exposure. LN exposure had no further impact on sucrose-induced glucose intolerance and increased plasma and liver triglycerides. Hepatic markers of fat synthesis and oxidation were concomitantly activated and 11βHSD-1 mRNA expression was increased by 53% in LN-Sucrose versus Con-Sucrose rats. Adiposity was increased by 26% in LN-Sucrose versus Con-Sucrose rats. Thus, LN exposure had minimal adverse metabolic effects despite high-sugar diet postweaning.

Influence of Long-Term Fertilization on Spore Density and Colonization of Arbuscular Mycorrhizal Fungi in a Brown Soil

NASA Astrophysics Data System (ADS)

Li, Dongdong; Luo, Peiyu; Yang, Jinfeng

2017-12-01

This study aims to explore changes of long-term fertilization on spore density and colonization of AMF (Arbuscular mycorrhizal fungi) under a 38-y long-term fertilization in a brown soil. Soil samples (0-20 cm,20-40cm,40-60cm)were taken from the six treatments of the long-term fertilization trial in October 2016:no fertilizer (CK), N1(mineral nitrogen fertilizer), N1P (mineral nitrogen and phosphate fertilizer), N1PK (mineral nitrogen, phosphate and potassic fertilizer), pig manure (M2), M2N1P (pig manure, mineral nitrogen andphosphate fertilizer).Spores were isolated from soils by wet sieving and sucrose density gradient centrifugation; mycorrhizal colonization levels were determined by the gridline intersect. The spore density was highest in the topsoils (0-20 cm), and was decreased with increasing of soil depth in each treatment. The spores density of M2N1P treatment was significantly higher than that of other treatments in each soil layer. Application of inorganic fertilizer (especially inorganic with organic fertilizer) can greatly improve the level of colonization. Our results suggested that long-term fertilization significantly affects spore density and colonization of AMF, however, spore density is not related to colonization rate.

21 CFR 172.869 - Sucrose oligoesters.

Code of Federal Regulations, 2011 CFR

2011-04-01

... Obtaining Method (1) Sucrose esters Not less than 90% “Method for Analyzing the Purity of Sucrose Fatty Acid... sample). Do. (8) Residual Methanol Not more than 10 milligrams/kilogram Method listed in the monograph...

21 CFR 172.869 - Sucrose oligoesters.

Code of Federal Regulations, 2010 CFR

2010-04-01

... Obtaining Method (1) Sucrose esters Not less than 90% “Method for Analyzing the Purity of Sucrose Fatty Acid... sample). Do. (8) Residual Methanol Not more than 10 milligrams/kilogram Method listed in the monograph...

Simultaneous determination of glucose, fructose, sucrose and sorbitol in the leaf and fruit peel of different apple cultivars by the HPLC-RI optimized method.

PubMed

Filip, Miuţa; Vlassa, Mihaela; Coman, Virginia; Halmagyi, Adela

2016-05-15

A high performance liquid chromatography method with refractive index detection (HPLC-RI), for simultaneous determination of glucose, fructose, sucrose and sorbitol in leaf and/or apple peel samples from nine apple (Malus domestica Borkh.) cultivars and rootstocks, originating from a germplasm collection, has been developed and validated. Box-Behnken design of response surface methodology was applied for the method optimization. The Carbosep Coregel 87H3 column was used under the optimum conditions predicted: mobile phase of H2SO4 0.005 mol L(-1) solution, flow rate of 0.3 mL min(-1) and column temperature of 35°C. The method was validated for linearity (R(2)>0.99), limits of detection (2.67-4.83 μg mL(-1)) and quantification (8.9-16.1 μg mL(-1)), precision (%RSD<5.05) and recovery (93.94-103.06%) and satisfactory results obtained. The sugars content varied across micropropagated plants in vitro, plants regenerated after cryostorage, growing trees in vivo, and fruit peel. Copyright © 2015 Elsevier Ltd. All rights reserved.

Central Composite Design (CCD) applied for statistical optimization of glucose and sucrose binary carbon mixture in enhancing the denitrification process

NASA Astrophysics Data System (ADS)

Lim, Jun-Wei; Beh, Hoe-Guan; Ching, Dennis Ling Chuan; Ho, Yeek-Chia; Baloo, Lavania; Bashir, Mohammed J. K.; Wee, Seng-Kew

2017-11-01

The present study provides an insight into the optimization of a glucose and sucrose mixture to enhance the denitrification process. Central Composite Design was applied to design the batch experiments with the factors of glucose and sucrose measured as carbon-to-nitrogen (C:N) ratio each and the response of percentage removal of nitrate-nitrogen (NO3 --N). Results showed that the polynomial regression model of NO3 --N removal had been successfully derived, capable of describing the interactive relationships of glucose and sucrose mixture that influenced the denitrification process. Furthermore, the presence of glucose was noticed to have more consequential effect on NO3 --N removal as opposed to sucrose. The optimum carbon sources mixture to achieve complete removal of NO3 --N required lesser glucose (C:N ratio of 1.0:1.0) than sucrose (C:N ratio of 2.4:1.0). At the optimum glucose and sucrose mixture, the activated sludge showed faster acclimation towards glucose used to perform the denitrification process. Later upon the acclimation with sucrose, the glucose uptake rate by the activated sludge abated. Therefore, it is vital to optimize the added carbon sources mixture to ensure the rapid and complete removal of NO3 --N via the denitrification process.

Effects of environmental enrichment on extinction and reinstatement of amphetamine self-administration and sucrose-maintained responding.

PubMed

Stairs, Dustin J; Klein, Emily D; Bardo, Michael T

2006-11-01

The current experiments aimed to determine whether differential rearing alters extinction and/or reinstatement of amphetamine self-administration or sucrose-maintained responding. Male Sprague-Dawley rats were raised in either an enriched condition or an isolated condition. Rats were then trained to lever press on a continuous reinforcement schedule across either 15 daily amphetamine self-administration sessions or 15 sucrose-reinforced sessions, followed by 10 sessions of extinction. After the extinction sessions, priming doses of amphetamine (0, 0.25 or 1.0 mg/kg) were administered 15 min before the session, or sucrose (one or 10 pellets) was delivered non-contingently at the beginning of the session. Enriched condition rats showed greater extinction for amphetamine and sucrose-maintained responding than isolated condition rats. When primed with amphetamine, isolated condition rats reinstated responding following 0.25 mg/kg of amphetamine, whereas enriched condition rats only reinstated responding after 1.0 mg/kg of amphetamine. Isolated condition rats failed to reinstate responding following sucrose delivery, while enriched condition rats reinstated responding following the delivery of 10 sucrose pellets. These results indicate that environmental enrichment enhanced the extinction of both amphetamine and sucrose-maintained responding. Environmental enrichment also raised the reinstatement threshold specific to the amphetamine prime, suggesting a reduction in the incentive motivational effect of amphetamine.

Effect of sucrose and safflower oil preloads on short term appetite and food intake of young men.

PubMed

Woodend, D M; Anderson, G H

2001-12-01

The effects of carbohydrate and fat on satiety have been examined primarily through meal composition studies. The purpose of this study was to compare the effects of pure sucrose and safflower oil, isovolumetric beverage preloads, on appetite (measured every 15 minutes by visual analogue scales) and food intake 60 minutes later. Young men consumed 0, 418, 836 and 1254 kJ of sucrose in the first two experiments and these same doses of safflower oil in the third. Finally, the largest doses of sucrose and safflower oil were compared. Sucrose, but not safflower oil, suppressed average appetite compared with control. In experiment 2, food intake was reduced (p<0.05) by 518 kJ after the 418 and 836 kJ preloads and by 1129 kJ after the 1254 kJ sucrose preload. Only the 1254 kJ dose of safflower oil significantly suppressed food intake by 480 kJ in the third experiment. When the 1254 kJ doses were compared directly, sucrose suppressed food intake by 653 kJ compared with control where as safflower oil did not. It is concluded that, in the short-term, sucrose produces a dose dependent reduction in appetite and food intake that is greater than that produced by safflower oil.

Reconstructing the Initial Density Field of the Local Universe: Methods and Tests with Mock Catalogs

NASA Astrophysics Data System (ADS)

Wang, Huiyuan; Mo, H. J.; Yang, Xiaohu; van den Bosch, Frank C.

2013-07-01

Our research objective in this paper is to reconstruct an initial linear density field, which follows the multivariate Gaussian distribution with variances given by the linear power spectrum of the current cold dark matter model and evolves through gravitational instabilities to the present-day density field in the local universe. For this purpose, we develop a Hamiltonian Markov Chain Monte Carlo method to obtain the linear density field from a posterior probability function that consists of two components: a prior of a Gaussian density field with a given linear spectrum and a likelihood term that is given by the current density field. The present-day density field can be reconstructed from galaxy groups using the method developed in Wang et al. Using a realistic mock Sloan Digital Sky Survey DR7, obtained by populating dark matter halos in the Millennium simulation (MS) with galaxies, we show that our method can effectively and accurately recover both the amplitudes and phases of the initial, linear density field. To examine the accuracy of our method, we use N-body simulations to evolve these reconstructed initial conditions to the present day. The resimulated density field thus obtained accurately matches the original density field of the MS in the density range 0.3 \\lesssim \\rho /\\bar{\\rho } \\lesssim 20 without any significant bias. In particular, the Fourier phases of the resimulated density fields are tightly correlated with those of the original simulation down to a scale corresponding to a wavenumber of ~1 h Mpc-1, much smaller than the translinear scale, which corresponds to a wavenumber of ~0.15 h Mpc-1.

21 CFR 172.869 - Sucrose oligoesters.

Code of Federal Regulations, 2014 CFR

2014-04-01

... than 40% Do. Do. (5) Free Sucrose Not more than 0.5% “Free Sucrose Method,” issued by Mitsubishi... Convention, 12601 Twinbrook Pkwy., Rockville, MD 20852 (Internet address http://www.usp.org) (7) Residue on...

Transport of Stachyose and Sucrose by Vacuoles of Japanese Artichoke (Stachys sieboldii) Tubers 1

PubMed Central

Keller, Felix

1992-01-01

Vacuoles are the stores for large amounts of stachyose [αgal (1,6) αgal (1,6) αglc (1,2) βfru] in tubers of Japanese artichoke (Stachys sieboldii). The uptake of stachyose by these vacuoles was examined and compared with that of sucrose. The uptake mechanisms of both sugars were quite similar. The kinetics showed a single saturable response to increasing external concentrations of 14C-sugars with similar apparent Km values of about 50 and 30 millimolar for stachyose and sucrose, respectively. The uptake rates, however, were always higher for stachyose than for sucrose. Stachyose and sucrose uptake was inhibited by fructose and raffinose, and, reciprocally, by sucrose and stachyose, but not by glucose or galactose. The main structural feature common to all sugars recognized by the uptake systems seems to be a terminal fructosyl residue. The uptake of both sugars was stimulated by Mg-ATP and inorganic pyrophosphate, suggesting a proton-sugar antiport system. The possibility that stachyose and sucrose might be transported by the same carrier is discussed. PMID:16668659

Nectar secretion requires sucrose phosphate synthases and the sugar transporter SWEET9.

PubMed

Lin, I Winnie; Sosso, Davide; Chen, Li-Qing; Gase, Klaus; Kim, Sang-Gyu; Kessler, Danny; Klinkenberg, Peter M; Gorder, Molly K; Hou, Bi-Huei; Qu, Xiao-Qing; Carter, Clay J; Baldwin, Ian T; Frommer, Wolf B

2014-04-24

Angiosperms developed floral nectaries that reward pollinating insects. Although nectar function and composition have been characterized, the mechanism of nectar secretion has remained unclear. Here we identify SWEET9 as a nectary-specific sugar transporter in three eudicot species: Arabidopsis thaliana, Brassica rapa (extrastaminal nectaries) and Nicotiana attenuata (gynoecial nectaries). We show that SWEET9 is essential for nectar production and can function as an efflux transporter. We also show that sucrose phosphate synthase genes, encoding key enzymes for sucrose biosynthesis, are highly expressed in nectaries and that their expression is also essential for nectar secretion. Together these data are consistent with a model in which sucrose is synthesized in the nectary parenchyma and subsequently secreted into the extracellular space via SWEET9, where sucrose is hydrolysed by an apoplasmic invertase to produce a mixture of sucrose, glucose and fructose. The recruitment of SWEET9 for sucrose export may have been a key innovation, and could have coincided with the evolution of core eudicots and contributed to the evolution of nectar secretion to reward pollinators.

Inulin and erythritol as sucrose replacers in short-dough cookies: sensory, fracture, and acoustic properties.

PubMed

Laguna, Laura; Primo-Martín, Cristina; Salvador, Ana; Sanz, Teresa

2013-05-01

The effect of sucrose replacement by erythritol and inulin was studied in short-dough cookies using instrumental and sensory analysis. Two levels of replacement were used (25% and 50% of total sucrose content). Descriptive sensory analysis showed that the sucrose replacement affects visual and texture cookies characteristics, being the differences perceived by mouth greater than by hand. In general, sucrose substitutes produced a less crispy cookie and lower consumer acceptability, with the exception of 25% sucrose replacement by inulin. Matrix aeration attributes such as open and crumbly obtained by trained panel were important properties, and correlated positively with consumer acceptance and negatively with maximum force at break (hardness). Inulin cookies sensory properties were more similar to the control than the erythritol cookies. Also, consumer overall acceptance decreased significantly with sucrose replacement by erythritol. The analysis of texture and sound revealed that inulin cookies were softer whereas erythritol cookies were harder in comparison with control cookies; despite this difference, inulin cookies had similar sound characteristics to erythritol cookies. © 2013 Institute of Food Technologists®

Effects of treatment with sucrose in drinking water on liver histology, lipogenesis and lipogenic gene expression in rats fed high-fiber diet.

PubMed

Mašek, Tomislav; Filipović, Natalija; Vuica, Ana; Starčević, Kristina

2017-01-01

We studied the influence of sucrose in drinking water on liver histology, fatty acid profile and lipogenic genes expression in rats maintained on high-fiber. The experimental groups were: control group (water) and sucrose group (sucrose solution in drinking water, 30% w/v). Liver histology of sucrose treated rats revealed steatosis and increased number of αSMA immunoreactive cells without the signs of fibrosis. Sucrose treatment increased de novo lipogenesis, lipid peroxidation and MUFA content and decreased PUFA content, C18:2n6 and C20:4n6 content in total phospholipids and phosphatidylethanolamine and C18:2n6 content in cardiolipin. RT-qPCR revealed increase in Δ-9-desaturase and SREBP1c gene expression and decrease in the Δ-5-desaturase and elongase 5 expression. Treatment with sucrose extensively changes fatty acid composition of hepatic lipid and phospholipid classes including cardiolipin, increases oxidative stress and causes pathological changes in liver in rats maintained on high-fiber diet. Copyright © 2016 Elsevier Ltd. All rights reserved.

Secondary relaxations in supercooled and glassy sucrose-borate aqueous solutions.

PubMed

Longinotti, M Paula; Corti, Horacio R; Pablo, Juan J de

2008-10-13

The dielectric relaxation spectra of concentrated aqueous solutions of sucrose-borate mixtures have been measured in the supercooled and glassy regions in the frequency range of 40Hz to 2MHz. The secondary (beta) relaxation process was analyzed in the temperature range 183-233K at water contents between 20 and 30wt%. The relaxation times were obtained, and the activation energy of that process was calculated. In order to assess the effect of borate on the relaxation of disaccharide-water mixtures, we also studied the dielectric behavior of sucrose aqueous solutions in the same range of temperatures and water contents. Our findings support the view that, beyond a water content of approximately 20wt%, the secondary relaxation of water-sucrose and water-sucrose-borate mixtures adopts a universal character that can be explained in terms of a simple exponential function of the temperature scaled by the glass transition temperature (T(g)). The behavior observed for water-sucrose and water-sucrose-borate mixtures is compared with previous results obtained in other water-carbohydrate systems.

Analysis of carbohydrates by anion exchange chromatography and mass spectrometry.

PubMed

Bruggink, Cees; Maurer, Rolf; Herrmann, Heiko; Cavalli, Silvano; Hoefler, Frank

2005-08-26

A versatile liquid chromatographic platform has been developed for analysing underivatized carbohydrates using high performance anion exchange chromatography (HPAEC) followed by an inert PEEK splitter that splits the effluent to the integrated pulsed amperometric detector (IPAD) and to an on-line single quadrupole mass spectrometer (MS). Common eluents for HPAEC such as sodium hydroxide and sodium acetate are beneficial for the amperometric detection but not compatible with electrospray ionisation (ESI). Therefore a membrane-desalting device was installed after the splitter and prior to the ESI interface converting sodium hydroxide into water and sodium acetate into acetic acid. To enhance the sensitivity for the MS detection, 0.5 mmol/l lithium chloride was added after the membrane desalter to form lithium adducts of the carbohydrates. To compare sensitivity of IPAD and MS detection glucose, fructose, and sucrose were used as analytes. A calibration with external standards from 2.5 to 1000 pmole was performed showing a linear range over three orders of magnitude. Minimum detection limits (MDL) with IPAD were determined at 5 pmole levels for glucose to be 0.12 pmole, fructose 0.22 pmole and sucrose 0.11 pmole. With MS detection in the selected ion mode (SIM) the lithium adducts of the carbohydrates were detected obtaining MDL's for glucose of 1.49 pmole, fructose 1.19 pmole, and sucrose 0.36 pmole showing that under these conditions IPAD is 3-10 times more sensitive for those carbohydrates. The applicability of the method was demonstrated analysing carbohydrates in real world samples such as chicory inulin where polyfructans up to a molecular mass of 7000 g/mol were detected as quadrupoly charged lithium adducts. Furthermore mono-, di-, tri-, and oligosaccharides were detected in chicory coffee, honey and beer samples.

( sup 14 C)-Sucrose uptake by guard cell protoplasts of pisum sativum, argenteum mutant

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rohrig, K.; Raschke, K.

1991-05-01

Guard cells rely on import for their supply with reduced carbon. The authors tested by silicone oil centrifugation the ability of guard cell protoplasts to accumulated ({sup 14}C)-sucrose. Uptake rates were corrected after measurement of {sup 14}C-sorbitol and {sup 3}H{sub 2}O spaces. Sucrose uptake followed biphasic kinetics, with a high-affinity component below 1 mM external sucrose (apparent K{sub m} 0.8 mM at 25C) and a low-affinity nonsaturable component above. Uptake depended on pH (optimum at pH 5.0). Variations in the concentrations of external KCl, CCCP, and valinomycin indicated that about one-half of the sucrose uptake rate could be related tomore » an electrochemical gradient across the plasmalemma. Total uptake rates measured at 5 mM external sucrose seem to be sufficient to replenish emptied plastids with starch within a few hours.« less

Thalamic regulation of sucrose-seeking during unexpected reward omission

PubMed Central

Do-Monte, Fabricio H.; Minier-Toribio, Angélica; Quiñones-Laracuente, Kelvin; Medina-Colón, Estefanía M.; Quirk, Gregory J.

2017-01-01

SUMMARY The paraventricular nucleus of the thalamus (PVT) is thought to regulate behavioral responses under emotionally arousing conditions. Reward-associated cues activate PVT neurons, however, the specific PVT efferents regulating reward-seeking remain elusive. Using a cued sucrose-seeking task, we manipulated PVT activity under two emotionally distinct conditions: 1) when reward was available during the cue as expected, or 2) when reward was unexpectedly omitted during the cue. Pharmacological inactivation of the anterior PVT (aPVT), but not the posterior PVT, increased sucrose-seeking only when reward was omitted. Consistent with this, photoactivation of aPVT neurons abolished sucrose-seeking, and the firing of aPVT neurons differentiated reward availability. Photoinhibition of aPVT projections to the nucleus accumbens or to the amygdala increased or decreased, respectively, sucrose-seeking only when reward was omitted. Our findings suggest that PVT bidirectionally modulates sucrose-seeking under the negative (frustrative) conditions of reward omission. PMID:28426970

Engineered Enterobacter aerogenes for efficient utilization of sugarcane molasses in 2,3-butanediol production.

PubMed

Jung, Moo-Young; Park, Bu-Soo; Lee, Jinwon; Oh, Min-Kyu

2013-07-01

Sugarcane molasses is considered to be a good carbon source for biorefinery due to its high sugar content and low price. Sucrose occupies more than half of the sugar in the molasses. Enterobacter aerogenes is a good host strain for 2,3-butanediol production, but its utilization of sucrose is not very efficient. To improve sucrose utilization in E. aerogenes, a sucrose regulator (ScrR) was disrupted from the genomic DNA. The deletion mutation increased the sucrose consumption rate significantly when sucrose or sugarcane molasses was used as a carbon source. The 2,3-butanediol production from sugarcane molasses by the mutant was enhanced by 60% in batch fermentation compared to that by the wild type strain. In fed-batch fermentation, 98.69 g/L of 2,3-butanediol production was achieved at 36 h. Copyright © 2013 Elsevier Ltd. All rights reserved.

A requirement for sucrose in xylem sap flow from dormant maple trees.

PubMed

Johnson, R W; Tyree, M T; Dixon, M A

1987-06-01

The response of excised stem segments of several tree species to freezing and thawing cycles was studied. All species studied (Thuja occidentalis, Fagus grandifolia, and Betula papyrifera) except maple (Acer spp.) exuded sap while freezing and absorbed on thawing. Maple stems absorbed sap while freezing and exuded sap during the thaw only when sucrose was present in the vessel solution. Increased concentration of sucrose in the vessel sap led to increased exudation. In the absence of sucrose, maple stems absorbed sap on thawing. The presence of sucrose enhanced sap absorption during freezing cycles in maples. In general, large sugars, disaccharides and larger, could substitute for sucrose in the maple exudation response while sugar hexoses could not. The results are discussed in relation to the O'Malley-Milburn model (1983 Can J Bot 61: 3100-3106) of sap flow in maples.

A Requirement for Sucrose in Xylem Sap Flow from Dormant Maple Trees 1

PubMed Central

Johnson, Robert W.; Tyree, Melvin T.; Dixon, Michael A.

1987-01-01

The response of excised stem segments of several tree species to freezing and thawing cycles was studied. All species studied (Thuja occidentalis, Fagus grandifolia, and Betula papyrifera) except maple (Acer spp.) exuded sap while freezing and absorbed on thawing. Maple stems absorbed sap while freezing and exuded sap during the thaw only when sucrose was present in the vessel solution. Increased concentration of sucrose in the vessel sap led to increased exudation. In the absence of sucrose, maple stems absorbed sap on thawing. The presence of sucrose enhanced sap absorption during freezing cycles in maples. In general, large sugars, disaccharides and larger, could substitute for sucrose in the maple exudation response while sugar hexoses could not. The results are discussed in relation to the O'Malley-Milburn model (1983 Can J Bot 61: 3100-3106) of sap flow in maples. Images Fig. 2 PMID:16665468

Feeding behavior and social interactions of the Argentine ant Linepithema humile change with sucrose concentration.

PubMed

Sola, F J; Josens, R

2016-08-01

Liquid sugar baits are well accepted by the Argentine ant Linepithema humile and are suitable for the chemical control of this invasive species. We evaluated how sugar concentrations affect the foraging behavior of L. humile individuals. We quantified feeding variables for individual foragers (ingested load, feeding time and solution intake rate) when feeding on sucrose solutions of different concentrations, as well as post-feeding interactions with nestmates. Solutions of intermediate sucrose concentrations (10-30%) were the most consumed and had the highest intake rates, whereas solutions of high sucrose concentrations (60 and 70%) resulted in extended feeding times, low intake rates and ants having smaller crop loads. In terms of post-feeding interactions, individuals fed solutions of intermediate sucrose concentrations (20%) had the highest probability of conducting trophallaxis and the smallest latency to drop exposure (i.e. lowest time delay). Trophallaxis duration increased with increasing sucrose concentrations. Behavioral motor displays, including contacts with head jerking and walking with a gaster waggle, were lowest for individuals that ingested the more dilute sucrose solution (5%). These behaviors have been previously suggested to act as a communication channel for the activation and/or recruitment of nestmates. We show here that sucrose concentration affects feeding dynamics and modulates decision making related to individual behavior and social interactions of foragers. Our results indicate that intermediate sucrose concentrations (ca. 20%), appear to be most appropriate for toxic baits because they promote rapid foraging cycles, a high crop load per individual, and a high degree of stimulation for recruitment.

Sucrose regulation of ADP-glucose pyrophosphorylase subunit genes transcript levels in leaves and fruits

NASA Technical Reports Server (NTRS)

Li, Xiangyang; Xing, Jinpeng; Gianfagna, Thomas J.; Janes, Harry W.

2002-01-01

ADP-glucose pyrophosphorylase (AGPase, EC2.7.7.27) is a key regulatory enzyme in starch biosynthesis. The enzyme is a heterotetramer with two S and two B subunits. In tomato, there are three multiple forms of the S subunit gene. Agp S1, S2 and B are highly expressed in fruit from 10 to 25 days after anthesis. Agp S3 is only weakly expressed in fruit. Sucrose significantly elevates expression of Agp S1, S2 and B in both leaves and fruits. Agp S1 exhibits the highest degree of regulation by sucrose. In fact, sucrose may be required for Agp S1 expression. For excised leaves incubated in water, no transcripts for Agp S1 could be detected in the absence of sucrose, whereas it took up to 16 h in water before transcripts were no longer detectable for Agp S2 and B. Neither Agp S3 nor the tubulin gene is affected by sucrose, demonstrating that this response is specifically regulated by a carbohydrate metabolic signal, and is not due to a general increase in metabolism caused by sucrose treatment. Truncated versions of the promoter for Agp S1 indicate that a specific region 1.3-3.0 kb upstream from the transcription site is responsible for sucrose sensitivity. This region of the S1 promoter contains several cis-acting elements present in the promoters of other genes that are also regulated by sucrose. c2002 Elsevier Science Ireland Ltd. All rights reserved.

Consumption of sucrose, but not high fructose corn syrup, leads to increased adiposity and dyslipidaemia in the pregnant and lactating rat.

PubMed

Toop, C R; Muhlhausler, B S; O'Dea, K; Gentili, S

2015-02-01

Excess consumption of added sugars, including sucrose and high fructose corn syrup (HFCS-55), have been implicated in the global epidemics of obesity and type 2 diabetes. This study aimed to investigate and compare the impact of maternal consumption of sucrose or HFCS-55 during pregnancy and lactation on the metabolic health of the dam and her offspring at birth. Female Albino Wistar rats were given access to chow and water, in addition to a sucrose or HFCS-55 beverage (10% w/v) before, and during pregnancy and lactation. Maternal glucose tolerance was determined throughout the study, and a postmortem was conducted on dams following lactation, and on offspring within 24 h of birth. Sucrose and HFCS-55 consumption resulted in increased total energy intake compared with controls, however the increase from sucrose consumption was accompanied by a compensatory decrease in chow consumption. There was no effect of sucrose or HFCS-55 consumption on body weight, however sucrose consumption resulted in increased adiposity and elevated total plasma cholesterol in the dam, while HFCS-55 consumption resulted in increased plasma insulin and decreased plasma non-esterified fatty acids (NEFA). Maternal HFCS-55 consumption was associated with decreased relative liver weight and plasma NEFA in the offspring at birth. There was no effect of either treatment on pup weight at birth. These findings suggest that both sucrose and HFCS-55 consumption during pregnancy and lactation have the potential to impact negatively on maternal metabolic health, which may have adverse consequences for the long-term health of the offspring.

The effect of maternal intake of sucrose or high-fructose corn syrup (HFCS)-55 during gestation and lactation on lipogenic gene expression in rat offspring at 3 and 12 weeks of age.

PubMed

Kaur, H; Toop, C R; Muhlhausler, B S; Gentili, S

2018-06-18

Perinatal exposure to sucrose or high-fructose corn syrup-55 (HFCS-55) in rats has previously been associated with altered hepatic fat content and composition post-weaning, although the effects on hepatic metabolism are unknown. The current study aimed to determine the sex-specific effects of maternal consumption of sucrose or HFCS-55 on the expression of hepatic lipogenic genes in the offspring. Liver samples were collected from offspring of albino Wistar rats provided with ad libitum access to either water (control), 10% sucrose or 10% HFCS-55 solution during pregnancy and lactation at 3 weeks (control n=16, sucrose n=22, HFCS-55 n=16) and 12 weeks (control n=16, sucrose n=10, HFCS-55 n=16) of age. Hepatic expression of the transcription factors such as carbohydrate response element-binding protein, sterol regulatory element-binding protein-1c and downstream genes was determined by quantitative real-time PCR. Sucrose-exposed offspring had higher hepatic SREBP-1c messenger RNA expression compared with control and HFCS-55 groups at both 3 weeks (P=0.01) and 12 weeks (P=0.03) of age. There were no differences in the expression of other hepatic lipogenic genes between groups at either 3 or 12 weeks. Thus, perinatal exposure to sucrose may be more detrimental to offspring hepatic metabolism compared with HFCS-55, independent of sex, and it will be important to evaluate the longer-term effects of perinatal sucrose exposure in future studies.

Development of a quantitative GC-FID method for the determination of sucrose mono- and diesters in foods.

PubMed

Cucu, Tatiana; De Meulenaer, Bruno

2015-01-01

Sucrose esters (E 473) are emulsifiers used in foods to improve different technological properties. They should conform to the specifications laid down in Commission Regulation No. 231/2012 and be used at amounts not exceeding the maximal ones set by Commission Regulation No. 1129/2011. In order to be able to characterise commercial sucrose ester formulations and to evaluate whether they are used correctly by the food industry, a quantitative GC-FID method was developed. Standards of monoesters and diesters were isolated from commercial additive preparations because no commercial ones were available. Commercial sucrose monolaureate and in-house-synthesised sucrose diarachidonate were used as internal standards. The method showed limits of detection and quantification of 2.9 and 5.7 µg ml(-1) respectively for the monoesters and 42.8 and 129.7 µg ml(-1) respectively for the diesters. The analysed commercial additive formulations contained mainly mono- and diesters of palmitic and stearic acid with low amounts of free fatty acid and sucrose. Different food matrices were incurred with commercial sucrose esters formulations and recoveries ranged between 92% and 118% for the monoesters and between 77% and 120% for the diesters. Recovery of sucrose monoesters in cake was around 34% when no enzymatic treatment was applied, and about 64% when enzymatic treatment with Clara-Diastase was applied. This indicated that sucrose esters can interact strongly with the matrix during food production and that treatment with enzymes is essential to determine the esters' content accurately in some classes of food products.

Effects of glucose and sucrose variants of the caries-promoting Diet 2000 on the feeding patterns and parotid glands of prematurely weaned rats.

PubMed

Redman, Robert S

2015-03-01

The hypothesis of this study was that feeding glucose instead of sucrose in the cariogenic Diet 2000 to rats weaned at age 18 days would result in greater light/dark differences in feeding activity and secretion and storage of parotid salivary enzymes. Diet 2000 and a stock commercial diet (controls) were prepared in pelleted and powdered forms, as the increased mastication required by pellets has been shown to support circadian rhythms in rats. Food jars were weighed at lights on and just prior to lights off daily. Rats were euthanized at 25 days and their parotid glands removed, weighed, and analyzed for specific activities of the salivary enzymes α-amylase and deoxyribonuclease I. Light/dark differences in feeding activity were strong in the rats fed the pelleted stock diet and both powdered and pelleted glucose 2000 diets, moderate with the pelleted sucrose 2000 diet, and not significant with the powdered sucrose 2000 and stock diets. Light/dark differences in the parotid salivary enzymes were strong with the powdered glucose 2000 diet and the pelleted forms of the glucose and sucrose 2000 and stock diets, and not significant with the powdered stock and sucrose 2000 diets. Caries reportedly is higher in sucrose than glucose fed to rats in the standard powdered form of Diet 2000, mainly due to the colonizing advantage Streptococcus mutans gains with sucrose. These results suggest that additional factors are more feeding during lights on and less stimulation of parotid salivary secretion with the sucrose powder. Published by Elsevier Ltd.

Precursor binding to an 880-kDa Toc complex as an early step during active import of protein into chloroplasts.

PubMed

Chen, Kuan-Yu; Li, Hsou-min

2007-01-01

The import of protein into chloroplasts is mediated by translocon components located in the chloroplast outer (the Toc proteins) and inner (the Tic proteins) envelope membranes. To identify intermediate steps during active import, we used sucrose density gradient centrifugation and blue-native polyacrylamide gel electrophoresis (BN-PAGE) to identify complexes of translocon components associated with precursor proteins under active import conditions instead of arrested binding conditions. Importing precursor proteins in solubilized chloroplast membranes formed a two-peak distribution in the sucrose density gradient. The heavier peak was in a similar position as the previously reported Tic/Toc supercomplex and was too large to be analyzed by BN-PAGE. The BN-PAGE analyses of the lighter peak revealed that precursors accumulated in at least two complexes. The first complex migrated at a position close to the ferritin dimer (approximately 880 kDa) and contained only the Toc components. Kinetic analyses suggested that this Toc complex represented an earlier step in the import process than the Tic/Toc supercomplex. The second complex in the lighter peak migrated at the position of the ferritin trimer (approximately 1320 kDa). It contained, in addition to the Toc components, Tic110, Hsp93, and an hsp70 homolog, but not Tic40. Two different precursor proteins were shown to associate with the same complexes. Processed mature proteins first appeared in the membranes at the same fractions as the Tic/Toc supercomplex, suggesting that processing of transit peptides occurs while precursors are still associated with the supercomplex.

Precursor binding to an 880-kDa Toc complex as an early step during active import of protein into chloroplasts

PubMed Central

Chen, Kuan-Yu; Li, Hsou-min

2007-01-01

The import of protein into chloroplasts is mediated by translocon components located in the chloroplast outer (the Toc proteins) and inner (the Tic proteins) envelope membranes. To identify intermediate steps during active import, we used sucrose density gradient centrifugation and blue-native polyacrylamide gel electrophoresis (BN-PAGE) to identify complexes of translocon components associated with precursor proteins under active import conditions instead of arrested binding conditions. Importing precursor proteins in solubilized chloroplast membranes formed a two-peak distribution in the sucrose density gradient. The heavier peak was in a similar position as the previously reported Tic/Toc supercomplex and was too large to be analyzed by BN-PAGE. The BN-PAGE analyses of the lighter peak revealed that precursors accumulated in at least two complexes. The first complex migrated at a position close to the ferritin dimer (approximately 880 kDa) and contained only the Toc components. Kinetic analyses suggested that this Toc complex represented an earlier step in the import process than the Tic/Toc supercomplex. The second complex in the lighter peak migrated at the position of the ferritin trimer (approximately 1320 kDa). It contained, in addition to the Toc components, Tic110, Hsp93, and an hsp70 homolog, but not Tic40. Two different precursor proteins were shown to associate with the same complexes. Processed mature proteins first appeared in the membranes at the same fractions as the Tic/Toc supercomplex, suggesting that processing of transit peptides occurs while precursors are still associated with the supercomplex. PMID:17144891

Structural model of the 50S subunit of E.Coli ribosomes from solution scattering

DOE Office of Scientific and Technical Information (OSTI.GOV)

Svergun, D.I.; Koch, M.H.J.; Pedersen, J.S.

1994-12-31

The application of new methods of small-angle scattering data interpretation to a contrast variation study of the 50S ribosomal subunit of Escherichia coli in solution is described. The X-ray data from contrast variation with sucrose are analyzed in terms of the basic scattering curves from the volume inaccessible to sucrose and from the regions inside this volume occupied mainly by RNA and by proteins. From these curves models of the shape of the 50S and its RNA-rich core are evaluated and positioned so that their difference produces a scattering curve which is in good agreement with the scattering from themore » protein moiety. Basing on this preliminary model, the X-ray and neutron contrast variation data of the 50S subunit in aqueous solutions are interpreted in the frame of the advanced two-phase model described by the shapes of the 50S subunit and its RNA-rich core taking into account density fluctuations inside the RNA and the protein moiety. The shape of the envelope of the 50S subunit and of the RNA-rich core are evaluated with a resolution of about 40A. The shape of the envelope is in good agreement with the models of the 50S subunit obtained from electron microscopy on isolated particles. The shape of the RNA-rich core correlates well with the model of the entire particle determined by the image reconstruction from ordered sheets indicating that the latter model which is based on the subjective contouring of density maps is heavily biased towards the RNA.« less

Receptor-mediated endocytosis of asialoglycoproteins by rat liver hepatocytes: biochemical characterization of the endosomal compartments

PubMed Central

1985-01-01

The endocytic compartments of the asialoglycoprotein (ASGP) pathway in rat hepatocytes were studied using a combined morphological and biochemical approach in the isolated perfused liver. Use of electron microscopic tracers and a temperature-shift protocol to synchronize ligand entry confirmed the route of ASGP internalization observed in our previous in vivo studies (1) and established conditions under which we could label the contents of successive compartments in the pathway for subcellular fractionation studies. Three endosomal compartments were demonstrated in which ASGPs appear after they enter the cell via coated pits and vesicles but before they reach their site of degradation in lysosomes. These three compartments could be distinguished by their location within the hepatocyte, by their morphological appearance in situ, and by their density in sucrose gradients. The distributions of ASGP receptors, both accessible and latent (revealed by detergent permeabilization), were also examined and compared with that of ligand during subcellular fractionation. Most accessible ASGP receptors co-distributed with conventional plasma membrane markers. However, hepatocytes contain a substantial intracellular pool of latent ASGP binding sites that exceeds the number of cell surface receptors and whose presence is not dependent on ASGP exposure. The distribution of these latent ASGP receptors on sucrose gradients (detected either immunologically or by binding assays) was coincident with that of ligand sequestered within the early endosome compartments. In addition, both early endosomes and the membrane vesicles containing latent ASGP receptors had high cholesterol content, because both shifted markedly in density upon exposure to digitonin. PMID:2866191

Buoyancy-induced mixing during wash and elution steps in expanded bed adsorption.

PubMed

Fee, C J; Liten, A D

2001-01-01

Buoyancy-induced mixing occurs during expanded bed adsorption processes when the feed stream entering the bottom of the system has a lower density than that of the fluid above it. In the absence of a headspace, mixing in the expanded bed can be modeled as a single, well-mixed vessel, with first-order dynamics. In the presence of a headspace, the system exhibits second-order dynamics for the densities typically encountered in protein chromatography, and can be modeled as two well-mixed vessels (the expanded bed and the headspace) arranged in series. In this paper, the mixing dynamics of the expanded bed are described and a mathematical model of the system is presented. Experimental measurements of density changes during the dilution of sucrose and salt solutions in a STREAMLINE 25 column are presented. These show excellent agreement with predictions using the model. A number of strategies for wash and elution in expanded mode, both in the presence and absence of headspace, are discussed.

Effect of salt on the response of birds to sucrose

USGS Publications Warehouse

Rogers, J.G.; Maller, O.

1973-01-01

The preference of male red-winged blackbirds for solutions of sucrose and sucrose with 0.03 M sodium chloride was tested, using a two-bottle choice test. Preliminary experiments demonstrated that the birds were indifferent to 0.03 M NaCl in water. Both control and experimental animals exhibited indifference to the solutions at the lowest concentration and aversion at the highest. The data suggest that the added sodium chloride makes the sucrose stimulus more discriminable.

Family history of alcoholism and the human brain response to oral sucrose.

PubMed

Eiler, William J A; Dzemidzic, Mario; Soeurt, Christina M; Carron, Claire R; Oberlin, Brandon G; Considine, Robert V; Harezlak, Jaroslaw; Kareken, David A

2018-01-01

A heightened hedonic response to sweet tastes has been associated with increased alcohol preference and alcohol consumption in both humans and animals. The principal goal of this study was to examine blood oxygenation level dependent (BOLD) activation to high- and low-concentration sweet solutions in subjects who are either positive (FHP) or negative (FHN) for a family history of alcoholism. Seventy-four non-treatment seeking, community-recruited, healthy volunteers (22.8 ± 1.6 SD years; 43% men) rated a range of sucrose concentrations in a taste test and underwent functional magnetic resonance imaging (fMRI) during oral delivery of water, 0.83 M, and 0.10 M sucrose. Sucrose compared to water produced robust activation in primary gustatory cortex, ventral insula, amygdala, and ventral striatum. FHP subjects displayed greater bilateral amygdala activation than FHN subjects in the low sucrose concentration (0.10 M). In secondary analyses, the right amygdala response to the 0.10 M sucrose was greatest in FHP women. When accounting for group differences in drinks per week, the family history groups remained significantly different in their right amygdala response to 0.10 M sucrose. Our findings suggest that the brain response to oral sucrose differs with a family history of alcoholism, and that this response to a mildly reinforcing primary reward might be an endophenotypic marker of alcoholism risk.

Physical properties and consumer liking of cookies prepared by replacing sucrose with tagatose.

PubMed

Taylor, T P; Fasina, O; Bell, L N

2008-04-01

The objective of this study was to investigate the suitability of tagatose, a minimally absorbed prebiotic monosaccharide, as a replacement for sucrose in cookies. A sucrose-containing cookie recipe was prepared as the control. Sucrose was replaced with tagatose at various levels ranging from 25% to 100%. Cookies containing fructose were also prepared for comparison due to the structural similarities between tagatose and fructose. The rheological properties of the dough were measured using texture profile analysis. The baked cookies were evaluated for spread, color, and hardness. For tagatose-containing cookies, the extent of likeness was evaluated by 53 untrained panelists using a 9-point hedonic scale. When sucrose was replaced by tagatose, doughs with similar rheological properties to the control resulted. The tagatose-containing cookies were harder and darker with a lower spread than the control. Sensory data indicated that panelists liked the brown color of the 100% tagatose cookies better than the control, but disliked their sweetness. Overall likeness scores of the control and cookies made by replacing half of the sucrose with tagatose were the same. Tagatose appears to be suitable as a partial replacer for sucrose in cookies based on similar dough properties, cookie properties, and likeness scores. Using tagatose to replace sucrose in foods would reduce the amount of metabolizeable sugars in the diet as well as provide the desirable prebiotic effect.

Cloning and characterization of the Cerasus humilis sucrose phosphate synthase gene (ChSPS1)

PubMed Central

Du, Junjie; Mu, Xiaopeng; Wang, Pengfei

2017-01-01

Sucrose is crucial to the growth and development of plants, and sucrose phosphate synthase (SPS) plays a key role in sucrose synthesis. To understand the genetic and molecular mechanisms of sucrose synthesis in Cerasus humilis, ChSPS1, a homologue of SPS, was cloned using RT-PCR. Sequence analysis showed that the open reading frame (ORF) sequence of ChSPS1 is 3174 bp in length, encoding a predicted protein of 1057 amino acids. The predicted protein showed a high degree of sequence identity with SPS homologues from other species. Real-time RT-PCR analysis showed that ChSPS1 mRNA was detected in all tissues and the transcription level was the highest in mature fruit. There is a significant positive correlation between expression of ChSPS1 and sucrose content. Prokaryotic expression of ChSPS1 indicated that ChSPS1 protein was expressed in E. coli and it had the SPS activity. Overexpression of ChSPS1 in tobacco led to upregulation of enzyme activity and increased sucrose contents in transgenic plants. Real-time RT-PCR analysis showed that the expression of ChSPS1 in transgenic tobacco was significantly higher than in wild type plants. These results suggested that ChSPS1 plays an important role in sucrose synthesis in Cerasus humilis. PMID:29036229

Responding for sucrose and wheel-running reinforcement: effects of sucrose concentration and wheel-running reinforcer duration.

PubMed

Belke, Terry W; Hancock, Stephanie D

2003-03-01

Six male albino rats were placed in running wheels and exposed to a fixed-interval 30-s schedule of lever pressing that produced either a drop of sucrose solution or the opportunity to run for a fixed duration as reinforcers. Each reinforcer type was signaled by a different stimulus. In Experiment 1, the duration of running was held constant at 15 s while the concentration of sucrose solution was varied across values of 0, 2.5. 5, 10, and 15%. As concentration decreased, postreinforcement pause duration increased and local rates decreased in the presence of the stimulus signaling sucrose. Consequently, the difference between responding in the presence of stimuli signaling wheel-running and sucrose reinforcers diminished, and at 2.5%, response functions for the two reinforcers were similar. In Experiment 2, the concentration of sucrose solution was held constant at 15% while the duration of the opportunity to run was first varied across values of 15, 45, and 90 s then subsequently across values of 5, 10, and 15 s. As run duration increased, postreinforcement pause duration in the presence of the wheel-running stimulus increased and local rates increased then decreased. In summary, inhibitory aftereffects of previous reinforcers occurred when both sucrose concentration and run duration varied; changes in responding were attributable to changes in the excitatory value of the stimuli signaling the two reinforcers.

Enamel and dentine demineralization by a combination of starch and sucrose in a biofilm - caries model.

PubMed

Botelho, Juliana Nunes; Villegas-Salinas, Mario; Troncoso-Gajardo, Pía; Giacaman, Rodrigo Andrés; Cury, Jaime Aparecido

2016-05-20

Sucrose is the most cariogenic dietary carbohydrate and starch is considered non-cariogenic for enamel and moderately cariogenic for dentine. However, the cariogenicity of the combination of starch and sucrose remains unclear. The aim of this study was to evaluate the effect of this combination on Streptococcus mutans biofilm composition and enamel and dentine demineralization. Biofilms of S. mutans UA159 were grown on saliva-coated enamel and dentine slabs in culture medium containing 10% saliva. They were exposed (8 times/day) to one of the following treatments: 0.9% NaCl (negative control), 1% starch, 10% sucrose, or 1% starch and 10% sucrose (starch + sucrose). To simulate the effect of human salivary amylase on the starch metabolization, the biofilms were pretreated with saliva before each treatment and saliva was also added to the culture medium. Acidogenicity of the biofilm was estimated by evaluating (2 times/day) the culture medium pH. After 4 (dentine) or 5 (enamel) days of growth, biofilms (n = 9) were individually collected, and the biomass, viable microorganism count, and polysaccharide content were quantified. Dentine and enamel demineralization was assessed by determining the percentage of surface hardness loss. Biofilms exposed to starch + sucrose were more acidogenic and caused higher demineralization (p < 0.0001) on either enamel or dentine than those exposed to each carbohydrate alone. The findings suggest that starch increases the cariogenic potential of sucrose.

Neonicotinoids decrease sucrose responsiveness of honey bees at first contact.

PubMed

Démares, Fabien J; Pirk, Christian W W; Nicolson, Susan W; Human, Hannelie

2018-07-01

For two decades, neonicotinoid insecticides have been extensively used worldwide. Targeting neuronal receptors, they have deleterious effects on the behaviour and physiology of many insects. Bees are exposed to these insecticides in pollen and nectar while providing pollination services to agricultural crops, and neonicotinoids have been shown to impair navigation and decrease their foraging activity. We have previously reported the effect of dietary thiamethoxam on sucrose responsiveness of young worker bees. Here, we exposed caged foragers to sublethal acute doses of clothianidin, imidacloprid, and thiamethoxam, then tested them individually for sucrose responsiveness using standard methods. In addition, we tested the response to a range of sucrose solutions laced with neonicotinoids on bees previously unexposed to neonicotinoids. This paradigm mimics the situation where foragers would first encounter poisoned nectars varying in sugar concentration. Bees were exposed to the insecticides in the feeding solution for 24 h before testing, or in the test solutions, or both. The three compounds had a detrimental effect on responses to mid-to-high sucrose concentrations under all experimental conditions, and unexposed bees tested with laced sucrose displayed unexpected low responses to the higher sucrose concentrations tested. This attenuation of sucrose response is further evidence that neonicotinoids are multisensory disruptors, with potent actions against pollinators and other beneficial insects at first contact. Copyright © 2018 Elsevier Ltd. All rights reserved.

Functional Analysis of Arabidopsis Sucrose Transporters

DOE Office of Scientific and Technical Information (OSTI.GOV)

John M. Ward

2009-03-31

Sucrose is the main photosynthetic product that is transported in the vasculature of plants. The long-distance transport of carbohydrates is required to support the growth and development of net-importing (sink) tissues such as fruit, seeds and roots. This project is focused on understanding the transport mechanism sucrose transporters (SUTs). These are proton-coupled sucrose uptake transporters (membrane proteins) that are required for transport of sucrose in the vasculature and uptake into sink tissues. The accomplishments of this project included: 1) the first analysis of substrate specificity for any SUT. This was accomplished using electrophysiology to analyze AtSUC2, a sucrose transporter frommore » companion cells in Arabidopsis. 2) the first analysis of the transport activity for a monocot SUT. The transport kinetics and substrate specificity of HvSUT1 from barley were studied. 3) the first analysis of a sucrose transporter from sugarcane. and 4) the first analysis of transport activity of a sugar alcohol transporter homolog from plants, AtPLT5. During this period four primary research papers, funded directly by the project, were published in refereed journals. The characterization of several sucrose transporters was essential for the current effort in the analysis of structure/function for this gene family. In particular, the demonstration of strong differences in substrate specificity between type I and II SUTs was important to identify targets for site-directed mutagenesis.« less

Aspartame and sucrose produce a similar increase in the plasma phenylalanine to large neutral amino acid ratio in healthy subjects.

PubMed

Burns, T S; Stargel, W W; Tschanz, C; Kotsonis, F N; Hurwitz, A

1991-01-01

Aspartame (L-aspartyl-L-phenylalanine methyl ester) consumption has been postulated to increase brain phenylalanine levels by increasing the molar ratio of the plasma phenylalanine concentration to the sum of the plasma concentrations of the other large neutral amino acids (Phe/LNAA). Dietary manipulations with carbohydrate or protein can also produce changes in the Phe/LNAA value. To compare the effects of aspartame and carbohydrate on Phe/LNAA, beverages sweetened with aspartame, sucrose, and aspartame plus sucrose, and unsweetened beverage were ingested by 8 healthy, fasted subjects in a randomized, four-way crossover design. The beverages were sweetened with an amount of aspartame (500 mg) and/or sucrose (100 g) approximately equivalent to that used to sweeten 1 liter of soft drink. The baseline-corrected plasma Phe/LNAA values did not differ significantly following ingestion of aspartame or sucrose. Following aspartame alone, the high mean ratio increased 26% over baseline 1 h after ingestion. Following sucrose alone, the high mean ratio increased 19% at 2.5 h. Sucrose increased the Phe/LNAA value due to an insulin-mediated decrease in the plasma LNAA, while aspartame increased the ratio by increasing the plasma Phe concentration. These findings indicate that similar increases in plasma Phe/LNAA occur when healthy, fasting subjects ingest amounts of equivalent sweetness of sucrose or aspartame.

Linear-scaling method for calculating nuclear magnetic resonance chemical shifts using gauge-including atomic orbitals within Hartree-Fock and density-functional theory.

PubMed

Kussmann, Jörg; Ochsenfeld, Christian

2007-08-07

Details of a new density matrix-based formulation for calculating nuclear magnetic resonance chemical shifts at both Hartree-Fock and density functional theory levels are presented. For systems with a nonvanishing highest occupied molecular orbital-lowest unoccupied molecular orbital gap, the method allows us to reduce the asymptotic scaling order of the computational effort from cubic to linear, so that molecular systems with 1000 and more atoms can be tackled with today's computers. The key feature is a reformulation of the coupled-perturbed self-consistent field (CPSCF) theory in terms of the one-particle density matrix (D-CPSCF), which avoids entirely the use of canonical MOs. By means of a direct solution for the required perturbed density matrices and the adaptation of linear-scaling integral contraction schemes, the overall scaling of the computational effort is reduced to linear. A particular focus of our formulation is to ensure numerical stability when sparse-algebra routines are used to obtain an overall linear-scaling behavior.

Antihypertensive potential of the aqueous extract which combine leaf of Persea americana Mill. (Lauraceae), stems and leaf of Cymbopogon citratus (D.C) Stapf. (Poaceae), fruits of Citrus medical L. (Rutaceae) as well as honey in ethanol and sucrose experimental model.

PubMed

Dzeufiet, Paul Désiré Djomeni; Mogueo, Amélie; Bilanda, Danielle Claude; Aboubakar, Bibi-Farouck Oumarou; Tédong, Léonard; Dimo, Théophile; Kamtchouing, Pierre

2014-12-17

The present study was designed to evaluate the effects of the aqueous extract obtained from the mixture of fresh leaf of Persea americana, stems and fresh leaf of Cymbopogon citratus, fruits of Citrus medica and honey on ethanol and sucrose induced hypertension in rats. Rats were divided into eight groups of 6 rats each and daily treated for 5 weeks. The control group received distilled water (1 mL/kg) while rats of groups 2, 3 and 4 received ethanol 40 degrees (3 g/kg/day), 10% sucrose as drinking water and the two substances respectively. The remaining groups received in addition to sucrose and ethanol, the aqueous extract (50, 100 and 150 mg/kg) or nifedipine (10 mg/kg) respectively. Many parameters including hemodynamic, biochemical and histopathological were assessed at the end of the study. The concomitant consumption of ethanol and sucrose significantly (p < 0.001) increased the blood pressure and the heart rate compared to distilled water treated-rats. The levels of total cholesterol, LDL-cholesterol, triglycerides, atherogenic index, glucose, proteins, AST, ALT, creatinin, potassium, sodium and albumin increased while the HDL-cholesterol decreased under ethanol and sucrose feeding. Chronic ethanol and sucrose intake significantly decreased the activities of superoxide dismutase (SOD) and catalase (CAT) as well as the contents of reduced glutathione (GSH) and nitrites whereas elevated the malondialdehyde (MDA) levels. Histological analysis revealed among other vascular congestion, inflammation, tubular clarification and thickening of the vessel wall in rats treated with alcohol and sucrose. Administration of the aqueous extract or nifedipine prevented the hemodynamic, biochemical, oxidative and histological impairments induced chronic ethanol and sucrose consumption. Current results suggest that the aqueous extract used in this study possess antihypertensive activity against ethanol and sucrose induced hypertension in rats by the improvement of biochemical and oxidative status, and by protecting liver, kidney and vascular endothelium against damages induced by chronic consumption of ethanol and sucrose.

Insight into the substrate specificity change caused by the Y227H mutation of α-glucosidase III from the European honeybee (Apis mellifera) through molecular dynamics simulations.

PubMed

Na Ayutthaya, Pratchaya Pramoj; Chanchao, Chanpen; Chunsrivirot, Surasak

2018-01-01

Honey from the European honeybee, Apis mellifera, is produced by α-glucosidases (HBGases) and is widely used in food, pharmaceutical, and cosmetic industries. Categorized by their substrate specificities, HBGases have three isoforms: HBGase I, II and III. Previous experimental investigations showed that wild-type HBGase III from Apis mellifera (WT) preferred sucrose to maltose as a substrate, while the Y227H mutant (MT) preferred maltose to sucrose. This mutant can potentially be used for malt hydrolysis because it can efficiently hydrolyze maltose. In this work, to elucidate important factors contributing to substrate specificity of this enzyme and gain insight into how the Y227H mutation causes substrate specificity change, WT and MT homology models were constructed, and sucrose/maltose was docked into active sites of the WT and MT. AMBER14 was employed to perform three independent molecular dynamics runs for these four complexes. Based on the relative binding free energies calculated by the MM-GBSA method, sucrose is better than maltose for WT binding, while maltose is better than sucrose for MT binding. These rankings support the experimentally observed substrate specificity that WT preferred sucrose to maltose as a substrate, while MT preferred maltose to sucrose, suggesting the importance of binding affinity for substrate specificity. We also found that the Y227H mutation caused changes in the proximities between the atoms necessary for sucrose/maltose hydrolysis that may affect enzyme efficiency in the hydrolysis of sucrose/maltose. Moreover, the per-residue binding free energy decomposition results show that Y227/H227 may be a key residue for preference binding of sucrose/maltose in the WT/MT active site. Our study provides important and novel insight into the binding of sucrose/maltose in the active site of Apis mellifera HBGase III and into how the Y227H mutation leads to the substrate specificity change at the molecular level. This knowledge could be beneficial in the design of this enzyme for increased production of desired products.

Sucrose-induced analgesia during early life modulates adulthood learning and memory formation.

PubMed

Nuseir, Khawla Q; Alzoubi, Karem H; Alabwaini, Jehad; Khabour, Omar F; Kassab, Manal I

2015-06-01

This study is aimed at examining the long-term effects of chronic pain during early life (postnatal day 0 to 8weeks), and intervention using sucrose, on cognitive functions during adulthood in rats. Pain was induced in rat pups via needle pricks of the paws. Sucrose solution or paracetamol was administered for analgesia before the paw prick. Control groups include tactile stimulation to account for handling and touching the paws, and sucrose alone was used. All treatments were started on day one of birth and continued for 8weeks. At the end of the treatments, behavioral studies were conducted to test the spatial learning and memory using radial arm water maze (RAWM), as well as pain threshold via foot-withdrawal response to a hot plate apparatus. Additionally, the hippocampus was dissected, and blood was collected. Levels of neurotrophins (BDNF, IGF-1 and NT-3) and endorphins were assessed using ELISA. The results show that chronic noxious stimulation resulted in comparable foot-withdrawal latency between noxious and tactile groups. On the other hand, pretreatment with sucrose or paracetamol increased pain threshold significantly both in naive rats and noxiously stimulated rats (P<0.05). Chronic pain during early life impaired short-term memory, and sucrose treatment prevented such impairment (P<0.05). Sucrose significantly increased serum levels of endorphin and enkephalin. Chronic pain decreased levels of BDNF in the hippocampus and this decrease was prevented by sucrose and paracetamol treatments. Hippocampal levels of NT-3 and IGF-1 were not affected by any treatment. In conclusion, chronic pain induction during early life induced short memory impairment, and pretreatment with sucrose prevented this impairment via mechanisms that seem to involve BDNF. As evident in the results, sucrose, whether alone or in the presence of pre-noxious stimulation, increases pain threshold in such circumstances; most likely via a mechanism that involves an increase in endogenous opioids. Copyright © 2015 Elsevier Inc. All rights reserved.

The promoter activities of sucrose phosphate synthase genes in rice, OsSPS1 and OsSPS11, are controlled by light and circadian clock, but not by sucrose.

PubMed

Yonekura, Madoka; Aoki, Naohiro; Hirose, Tatsuro; Onai, Kiyoshi; Ishiura, Masahiro; Okamura, Masaki; Ohsugi, Ryu; Ohto, Chikara

2013-01-01

Although sucrose plays a role in sugar sensing and its signaling pathway, little is known about the regulatory mechanisms of the expressions of plant sucrose-related genes. Our previous study on the expression of the sucrose phosphate synthase gene family in rice (OsSPSs) suggested the involvement of sucrose sensing and/or circadian rhythm in the transcriptional regulation of OsSPS. To examine whether the promoters of OsSPSs can be controlled by sugars and circadian clock, we produced transgenic rice plants harboring a promoter-luciferase construct for OsSPS1 or OsSPS11 and analyzed the changes in the promoter activities by monitoring bioluminescence from intact transgenic plants in real-time. Transgenic plants fed sucrose, glucose, or mannitol under continuous light conditions showed no changes in bioluminescence intensity; meanwhile, the addition of sucrose increased the concentration of sucrose in the plants, and the mRNA levels of OsSPS remained constant. These results suggest that these OsSPS promoters may not be regulated by sucrose levels in the tissues. Next, we investigated the changes in the promoter activities under 12-h light/12-h dark cycles and continuous light conditions. Under the light-dark cycle, both OsSPS1 and OsSPS11 promoter activities were low in the dark and increased rapidly after the beginning of the light period. When the transgenic rice plants were moved to the continuous light condition, both P OsSPS1 ::LUC and P OsSPS11 ::LUC reporter plants exhibited circadian bioluminescence rhythms; bioluminescence peaked during the subjective day with a 27-h period: in the early morning as for OsSPS1 promoter and midday for OsSPS11 promoter. These results indicate that these OsSPS promoters are controlled by both light illumination and circadian clock and that the regulatory mechanism of promoter activity differs between the two OsSPS genes.

Sucrose uptake by pinocytosis in Amoeba proteus and the influence of external calcium

PubMed Central

1979-01-01

The relationship between Ca++ and pinocytosis was investigated in Amoeba proteus. Pinocytosis was induced with 0.01% alcian blue, a large molecular weight dye which binds irreversibly to the cell surface. The time-course and intensity of pinocytosis was monitored by following the uptake of [3H]SUCROSE. When the cells are exposed to 0.01% alcian blue, there is an immediate uptake of sucrose. The cells take up integral of 10% of their initial volume during the time-course of pinocytosis. The duration of pinocytosis in the amoeba is integral of 50 min, with maximum sucrose uptake occurring 15 min after the induction of pinocytosis. The pinocytotic uptake of sucrose is reversibly blocked at 3 degrees C and a decrease in pH increases the uptake of sucrose by pinocytosis. The process of pinocytosis is also dependent upon the concentration of the inducer in the external medium. The association between Ca++ and pinocytosis in A. proteus was investigated initially by determining the effect of the external Ca++ concentration on sucrose uptake induced by alcian blue. In Ca++-free medium, no sucrose uptake is observed in the presence of 0.01% alcian blue. As the Ca++ concentration is increased, up to a maximum of 0.1 mM, pinocytotic sucrose uptake is also increased. Increases in the external Ca++ concentration above 0.1 mM brings about a decrease in sucrose uptake. Further investigations into the association between Ca++ and pinocytosis demonstrated that the inducer of pinocytosis displaces surface calcium in the amoeba. It is suggested that Ca++ is involved in two separate stages in the process of pinocytosis; an initial displacement of surface calcium by the inducer which may increase the permeability of the membrane to solutes and a subsequent Ca++ influx bringing about localized increases in cytoplasmic Ca++ ion activity. PMID:512629

Expression of peach sucrose transporters in heterologous systems points out their different physiological role.

PubMed

Zanon, Laura; Falchi, Rachele; Hackel, Aleksandra; Kühn, Christina; Vizzotto, Giannina

2015-09-01

Sucrose is the major phloem-translocated component in a number of economically important plant species. The comprehension of the mechanisms involved in sucrose transport in peach fruit appears particularly relevant, since the accumulation of this sugar, during ripening, is crucial for the growth and quality of the fruit. Here, we report the functional characterisation and subcellular localisation of three sucrose transporters (PpSUT1, PpSUT2, PpSUT4) in peach, and we formulate novel hypotheses about their role in accumulation of sugar. We provide evidence, about the capability of both PpSUT1 and PpSUT4, expressed in mutant yeast strains to transport sucrose. The functionality of PpSUT1 at the plasma membrane, and of PpSUT4 at the tonoplast, has been demonstrated. On the other hand, the functionality of PpSUT2 was not confirmed: this protein is unable to complement two sucrose uptake-deficient mutant yeast strains. Our results corroborate the hypotheses that PpSUT1 partakes in phloem loading in leaves, and PpSUT4 sustains cell metabolism by regulating sucrose efflux from the vacuole. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Tactile learning and the individual evaluation of the reward in honey bees (Apis mellifera L.).

PubMed

Scheiner, R; Erber, J; Page, R E

1999-07-01

Using the proboscis extension response we conditioned pollen and nectar foragers of the honey bee (Apis mellifera L.) to tactile patterns under laboratory conditions. Pollen foragers demonstrated better acquisition, extinction, and reversal learning than nectar foragers. We tested whether the known differences in response thresholds to sucrose between pollen and nectar foragers could explain the observed differences in learning and found that nectar foragers with low response thresholds performed better during acquisition and extinction than ones with higher thresholds. Conditioning pollen and nectar foragers with similar response thresholds did not yield differences in their learning performance. These results suggest that differences in the learning performance of pollen and nectar foragers are a consequence of differences in their perception of sucrose. Furthermore, we analysed the effect which the perception of sucrose reward has on associative learning. Nectar foragers with uniform low response thresholds were conditioned using varying concentrations of sucrose. We found significant positive correlations between the concentrations of the sucrose rewards and the performance during acquisition and extinction. The results are summarised in a model which describes the relationships between learning performance, response threshold to sucrose, concentration of sucrose and the number of rewards.

Moderate High Fat Diet Increases Sucrose Self-Administration In Young Rats

PubMed Central

Figlewicz, Dianne P.; Jay, Jennifer L.; Acheson, Molly A.; Magrisso, Irwin J.; West, Constance H.; Zavosh, Aryana; Benoit, Stephen C.; Davis, Jon F.

2012-01-01

We have previously reported that a moderately high fat diet increases motivation for sucrose in adult rats. In this study, we tested the motivational, neurochemical, and metabolic effects of the high fat diet in male rats transitioning through puberty, during 5-8 weeks of age. We observed that the high fat diet increased motivated responding for sucrose, which was independent of either metabolic changes or changes in catecholamine neurotransmitter metabolites in the nucleus accumbens. However, AGRP mRNA levels in the hypothalamus were significantly elevated. We demonstrated that increased activation of AGRP neurons is associated with motivated behavior, and that exogenous (third cerebroventricular) AGRP administration resulted in significantly increased motivation for sucrose. These observations suggest that increased expression and activity of AGRP in the medial hypothalamus may underlie the increased responding for sucrose caused by the high fat diet intervention. Finally, we compared motivation for sucrose in pubertal vs. adult rats and observed increased motivation for sucrose in the pubertal rats, which is consistent with previous reports that young animals and humans have an increased preference for sweet taste, compared with adults. Together, our studies suggest that background diet plays a strong modulatory role in motivation for sweet taste in adolescent animals. PMID:23023044

Optimization of simultaneously enzymatic fructo- and inulo-oligosaccharide production using co-substrates of sucrose and inulin from Jerusalem artichoke.

PubMed

Kawee-Ai, Arthitaya; Ritthibut, Nuntinee; Manassa, Apisit; Moukamnerd, Churairat; Laokuldilok, Thunnop; Surawang, Suthat; Wangtueai, Sutee; Phimolsiripol, Yuthana; Regenstein, Joe M; Seesuriyachan, Phisit

2018-02-07

Prebiotic substances are extracted from various plant materials or enzymatic hydrolysis of different substrates. The production of fructo-oligosaccharide (FOS) and inulo-oligosaccharide (IOS) was performed by applying two substrates, sucrose and inulin; oligosaccharide yields were maximized using central composite design to evaluate the parameters influencing oligosaccharide production. Inulin from Jerusalem artichoke (5-15% w/v), sucrose (50-70% w/v), and inulinase from Aspergillus niger (2-7 U/g) were used as variable parameters for optimization. Based on our results, the application of sucrose and inulin as co-substrates for oligosaccharide production through inulinase hydrolysis and synthesis is viable in comparative to a method using a single substrate. Maximum yields (674.82 mg/g substrate) were obtained with 5.95% of inulin, 59.87% of sucrose, and 5.68 U/g of inulinase, with an incubation period of 9 hr. The use of sucrose and inulin as co-substrates in the reaction simultaneously produced FOS and IOS from sucrose and inulin. Total conversion yield was approximately 67%. Our results support the high value-added production of oligosaccharides using Jerusalem artichoke, which is generally used as a substrate in prebiotics and/or bioethanol production.

Correlation Between Bone Density and Instantaneous Torque at Implant Site Preparation: A Validation on Polyurethane Foam Blocks of a Device Assessing Density of Jawbones.

PubMed

Di Stefano, Danilo Alessio; Arosio, Paolo

2016-01-01

Bone density at implant placement sites is one of the key factors affecting implant primary stability, which is a determinant for implant osseointegration and rehabilitation success. Site-specific bone density assessment is, therefore, of paramount importance. Recently, an implant micromotor endowed with an instantaneous torque-measuring system has been introduced. The aim of this study was to assess the reliability of this system. Five blocks with different densities (0.16, 0.26, 0.33, 0.49, and 0.65 g/cm(3)) were used. A single trained operator measured the density of one of them (0.33 g/cm(3)), by means of five different devices (20 measurements/device). The five resulting datasets were analyzed through the analysis of variance (ANOVA) model to investigate interdevice variability. As differences were not significant (P = .41), the five devices were each assigned to a different operator, who collected 20 density measurements for each block, both under irrigation (I) and without irrigation (NI). Measurements were pooled and averaged for each block, and their correlation with the actual block-density values was investigated using linear regression analysis. The possible effect of irrigation on density measurement was additionally assessed. Different devices provided reproducible, homogenous results. No significant interoperator variability was observed. Within the physiologic range of densities (> 0.30 g/cm(3)), the linear regression analysis showed a significant linear correlation between the mean torque measurements and the actual bone densities under both drilling conditions (r = 0.990 [I], r = 0.999 [NI]). Calibration lines were drawn under both conditions. Values collected under irrigation were lower than those collected without irrigation at all densities. The NI/I mean torque ratio was shown to decrease linearly with density (r = 0.998). The mean error introduced by the device-operator system was less than 10% in the range of normal jawbone density. Measurements performed with the device were linearly correlated with the blocks' bone densities. The results validate the device as an objective intraoperative tool for bone-density assessment that may contribute to proper jawbone-density evaluation and implant-insertion planning.

The Path of Carbon in Photosynthesis XIX. The Identification of Sucrose Phosphate in Sugar Beet Leaves

DOE R&D Accomplishments Database

Buchanan, J. G.

1952-09-01

The recognition and characterization of a sucrose phosphate as an intermediate in sucrose by synthesis by green plants is described. A tentative structure for this phosphate is proposed and its mode of formation suggested.

Sucrose tricarboxylate by sonocatalysed TEMPO-mediated oxidation.

PubMed

Lemoine, S; Thomazeau, C; Joannard, D; Trombotto, S; Descotes, G; Bouchu, A; Queneau, Y

2000-06-16

Oxidation of sucrose by the NaOCl/TEMPO system provided sucrose tricarboxylate without the addition of sodium bromide as co-catalyst when high-frequency (500 kHz) ultrasound was applied, in contrast to very limited conversion without sonication. In the presence of sodium bromide, sonication also caused acceleration of the oxidation. The rate increase due to sonication of the oxidant system prior to sucrose addition suggests that ultrasound acts at the level of the formation of the nitrosonium ion, the active oxidising species in the catalytic cycle.

Prenatal Ethanol Increases Sucrose Reinforcement, an Effect Strengthened by Postnatal Association of Ethanol and Sucrose

PubMed Central

Culleré, Marcela Elena; Spear, Norman E.; Molina, Juan Carlos

2014-01-01

Late prenatal exposure to ethanol recruits sensory processing of the drug and of its motivational properties, an experience that leads to heightened ethanol affinity. Recent studies indicate common sensory and neurobiological substrates between this drug and sweet tastants. Using a recently developed operant conditioning technique for infant rats, we examined the effects of prenatal ethanol history upon sucrose self-administration (postnatal days, PDs 14–17). Prior to the last conditioning session, a low (0.5 g/kg) or a high (2.5 g/kg) ethanol dose were paired with sucrose. The intention was to determine if ethanol would inflate or devalue the reinforcing capability of the tastant and if these effects are dependent upon prenatal ethanol history. Male and female pups prenatally exposed to ethanol (2.0 g/kg) responded more when reinforced with sucrose than pups lacking this antenatal experience. Independently of prenatal status, a low ethanol dose (0.5 g/kg) enhanced the reinforcing capability of sucrose while the highest dose (2.5 g/kg) seemed to ameliorate the motivational properties of the tastant. During extinction (PD 18), two factors were critical in determining persistence of responding despite reinforcement omission. Pups prenatally exposed to ethanol that subsequently experienced the low ethanol dose paired with sucrose, showed higher resistance to extinction. The effects here reported were not associated with differential blood alcohol levels across prenatal treatments. These results indicate that fetal ethanol experience promotes affinity for a natural sweet reinforcer and that low doses of ethanol are also capable of enhancing the positive motivational consequences of sucrose when ethanol and sucrose are paired during infancy. PMID:24398347

Development and evaluation of a novel polymeric hydrogel of sucrose acrylate-co-polymethylacrylic acid for oral curcumin delivery.

PubMed

Huang, Sijin; Wang, Jialei; Shang, Qing

2017-02-01

A monomer of sucrose acrylate (AC-sucrose) was synthesized by conjugating starting compound sucrose with methyl acrylate (MA). The obtained AC-sucrose was characterized by mass spectrometry (MS) and Fourier transform infrared (FTIR) spectroscopy. AC-sucrose was selected as a monomer to fabricate a novel pH sensitive hydrogel via free radical polymerization. The inner morphology of the final hydrogel was observed with an S-4800 scanning electron microscope (SEM). The swelling and de-swelling behaviors of the hydrogel chips were also studied. Curcumin (CUR) was selected as a model drug and loaded into the final hydrogel. The release profiles of CUR were performed via dialysis method in pH 1.2, 6.8 and 7.4 buffers, respectively. Mass and FTIR spectra confirmed the synthesis of AC-sucrose. SEM photographs showed that poly(AC-sucrose-co-MAA) hydrogels had many 3D meshes. In pH 1.2 buffer, the hydrogel chips showed the biggest swelling ratio (SR) of 34.4 ± 1.9%. However, in pH 7.4 buffer, the SRs of the hydrogel chips reached to 368.7 ± 28.0%, which suggested that the hydrogel had an excellent pH sensibility. The releasing profiles showed that only 4.6 ± 0.4% of CUR was released in pH 1.2 buffer but 93.7 ± 4.7% of CUR was diffused into pH 7.4 buffer. These data suggested that the CUR-loaded poly (AC-sucrose-co-MAA) hydrogel could direct CUR to release in basic environments.

Sucrose modulation of radiofrequency-induced heating rates and cell death.

PubMed

Pulikkathara, Merlyn; Mark, Colette; Kumar, Natasha; Zaske, Ana Maria; Serda, Rita E

2017-09-01

Applied radiofrequency (RF) energy induces hyperthermia in tissues, facilitating vascular perfusion This study explores the impact of RF radiation on the integrity of the luminal endothelium, and then predominately explores the impact of altering the conductivity of biologically-relevant solutions on RF-induced heating rates and cell death. The ability of cells to survive high sucrose (i.e. hyperosmotic conditions) to achieve lower conductivity as a mechanism for directing hyperthermia is evaluated. RF radiation was generated using a capacitively-coupled radiofrequency system operating at 13.56 MHz. Temperatures were recorded using a FLIR SC 6000 infrared camera. RF radiation reduced cell-to-cell connections among endothelial cells and altered cell morphology towards a more rounded appearance at temperatures reported to cause in vivo vessel deformation. Isotonic solutions containing high sucrose and low levels of NaCl displayed low conductivity and faster heating rates compared to high salt solutions. Heating rates were positively correlated with cell death. Addition of sucrose to serum similarly reduced conductivity and increased heating rates in a dose-dependent manner. Cellular proliferation was normal for cells grown in media supplemented with 125 mM sucrose for 24 hours or for cells grown in 750 mM sucrose for 10 minutes followed by a 24 h recovery period. Sucrose is known to form weak hydrogen bonds in fluids as opposed to ions, freeing water molecules to rotate in an oscillating field of electromagnetic radiation and contributing to heat induction. The ability of cells to survive temporal exposures to hyperosmotic (i.e. elevated sucrose) conditions creates an opportunity to use sucrose or other saccharides to selectively elevate heating in specific tissues upon exposure to a radiofrequency field.

Sucrose Improves Insecticide Activity Against Drosophila suzukii (Diptera: Drosophilidae).

PubMed

Cowles, Richard S; Rodriguez-Saona, Cesar; Holdcraft, Robert; Loeb, Gregory M; Elsensohn, Johanna E; Hesler, Steven P

2015-04-01

The addition of sucrose to insecticides targeting spotted wing drosophila, Drosophila suzukii (Matsumura), enhanced lethality in laboratory, semifield, and field tests. In the laboratory, 0.1% sucrose added to a spray solution enhanced spotted wing drosophila feeding. Flies died 120 min earlier when exposed to spinosad residues at label rates enhanced with sucrose. Added sucrose reduced the LC50 for dried acetamiprid residues from 82 to 41 ppm in the spray solution. Laboratory bioassays of spotted wing drosophila mortality followed exposure to grape and blueberry foliage and/or fruit sprayed and aged in the field. On grape foliage, the addition of 2.4 g/liter of sugar with insecticide sprays resulted in an 11 and 6% increase of spotted wing drosophila mortality at 1 and 2 d exposures to residues, respectively, averaged over seven insecticides with three concentrations. In a separate experiment, spinetoram and cyantraniliprole reduced by 95-100% the larval infestation of blueberries, relative to the untreated control, 7 d after application at labeled rates when applied with 1.2 g/liter sucrose in a spray mixture, irrespective of rainfall; without sucrose infestation was reduced by 46-91%. Adding sugar to the organically acceptable spinosyn, Entrust, reduced larval infestation of strawberries by >50% relative to without sugar for five of the six sample dates during a season-long field trial. In a small-plot field test with blueberries, weekly applications in alternating sprays of sucrose plus reduced-risk insecticides, spinetoram or acetamiprid, reduced larval infestation relative to the untreated control by 76%; alternating bifenthrin and phosmet (without sucrose) reduced infestation by 65%. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Sucrose exposure in early life alters adult motivation and weight gain.

PubMed

Frazier, Cristianne R M; Mason, Peggy; Zhuang, Xiaoxi; Beeler, Jeff A

2008-09-17

The cause of the current increase in obesity in westernized nations is poorly understood but is frequently attributed to a 'thrifty genotype,' an evolutionary predisposition to store calories in times of plenty to protect against future scarcity. In modern, industrialized environments that provide a ready, uninterrupted supply of energy-rich foods at low cost, this genetic predisposition is hypothesized to lead to obesity. Children are also exposed to this 'obesogenic' environment; however, whether such early dietary experience has developmental effects and contributes to adult vulnerability to obesity is unknown. Using mice, we tested the hypothesis that dietary experience during childhood and adolescence affects adult obesity risk. We gave mice unlimited or no access to sucrose for a short period post-weaning and measured sucrose-seeking, food consumption, and weight gain in adulthood. Unlimited access to sucrose early in life reduced sucrose-seeking when work was required to obtain it. When high-sugar/high-fat dietary options were made freely-available, however, the sucrose-exposed mice gained more weight than mice without early sucrose exposure. These results suggest that early, unlimited exposure to sucrose reduces motivation to acquire sucrose but promotes weight gain in adulthood when the cost of acquiring palatable, energy dense foods is low. This study demonstrates that early post-weaning experience can modify the expression of a 'thrifty genotype' and alter an adult animal's response to its environment, a finding consistent with evidence of pre- and peri-natal programming of adult obesity risk by maternal nutritional status. Our findings suggest the window for developmental effects of diet may extend into childhood, an observation with potentially important implications for both research and public policy in addressing the rising incidence of obesity.

Sucrose and naltrexone prevent increased pain sensitivity and impaired long-term memory induced by repetitive neonatal noxious stimulation: Role of BDNF and β-endorphin.

PubMed

Nuseir, Khawla Q; Alzoubi, Karem H; Alhusban, Ahmed; Bawaane, Areej; Al-Azzani, Mohammed; Khabour, Omar F

2017-10-01

Pain in neonates is associated with short and long-term adverse outcomes. Data demonstrated that long-term consequences of untreated pain are linked to the plasticity of the neonate's brain. Sucrose is effective and safe for reducing painful procedures from single events. However, the mechanism of sucrose-induced analgesia is not fully understood. The role of the opioid system in this analgesia using the opioid receptor antagonist Naltrexone was investigated, plus the long-term effects on learning and memory formation during adulthood. Pain was induced in rat pups via needle pricks of the paws. Sucrose solution and/or naltrexone were administered before the pricks. All treatments started on day one of birth and continued for two weeks. At the end of 8weeks, behavioral studies were conducted to test spatial learning and memory using radial arm water maze (RAWM), and pain threshold via foot-withdrawal response to a hot plate. The hippocampus was dissected; levels of brain derived neurotrophic factor (BDNF) and endorphins were assessed using ELISA. Acute repetitive neonatal pain increased pain sensitivity later in life, while naltrexone with sucrose decreased pain sensitivity. Naltrexone and/or sucrose prevented neonatal pain induced impairment of long-term memory, while neonatal pain decreased levels of BDNF in the hippocampus; this decrease was averted by sucrose and naltrexone. Sucrose with naltrexone significantly increased β-endorphin levels in noxiously stimulated rats. In conclusion, naltrexone and sucrose can reverse increased pain sensitivity and impaired long-term memory induced by acute repetitive neonatal pain probably by normalizing BDNF expression and increasing β-endorphin levels. Copyright © 2017 Elsevier Inc. All rights reserved.

Fish oil prevents sucrose-induced fatty liver but exacerbates high-safflower oil-induced fatty liver in ddy mice.

PubMed

Yamazaki, Tomomi; Nakamori, Akiko; Sasaki, Eriko; Wada, Satoshi; Ezaki, Osamu

2007-12-01

Diets high in sucrose/fructose or fat can result in hepatic steatosis (fatty liver). We analyzed the effects of dietary fish oil on fatty liver induced by sucrose, safflower oil, and butter in ddY mice. In experiment I, mice were fed a high-starch diet [70 energy% (en%) starch] plus 20% (wt/wt) sucrose in the drinking water or fed a high-safflower oil diet (60 en%) for 11 weeks. As a control, mice were fed a high-starch diet with drinking water. Fish oil (10 en%) was either supplemented or not. Mice supplemented with sucrose or fed safflower oil showed a 1.7-fold or 2.2-fold increased liver triglyceride content, respectively, compared with that of control mice. Fish oil completely prevented sucrose-induced fatty liver, whereas it exacerbated safflower oil-induced fatty liver. Sucrose increased SREBP-1c and target gene messenger RNAs (mRNAs), and fish oil completely inhibited these increases. In experiment II, mice were fed a high-safflower oil or a high-butter diet, with or without fish oil supplementation. Fish oil exacerbated safflower oil-induced fatty liver but did not affect butter-induced fatty liver. Fish oil increased expression of peroxisome proliferator-activated receptor gamma (PPARgamma) and target CD36 mRNA in safflower oil-fed mice. These increases were not observed in sucrose-supplemented or butter-fed mice. The effects of dietary fish oil on fatty liver differ according to the cause of fatty liver; fish oil prevents sucrose-induced fatty liver but exacerbates safflower oil-induced fatty liver. The exacerbation of fatty liver may be due, at least in part, to increased expression of liver PPARgamma.

Pyruvate cycling and implications for regulation of gluconeogenesis in the insect, Manduca sexta L.

PubMed

Thompson, S N

2000-08-11

Pyruvate cycling was examined in the insect Manduca sexta L. (2-(13)C)pyruvate was injected into 5th instar larvae maintained on a semisynthetic high sucrose, low sucrose, or sucrose-free diet. Pyruvate cycling and gluconeogenesis were determined from the distribution of (13)C in blood metabolites, including trehalose, the blood sugar of insects, and alanine. Pyruvate cycling was evident from the (13)C enrichment of alanine C3, synthesized by transamination of pyruvate following carboxylation to oxaloacetate and cycling through phosphoenolpyruvate. Based on the relative (13)C enrichments of alanine C2 and C3, insects maintained on the high sucrose diet displayed higher levels of cycling than insects on the other diets. Insects on all the diets, when subsequently starved, displayed low levels of cycling. Gluconeogenesis was evident in insects on sucrose-free or low sucrose diets from the selective (13)C enrichment in trehalose. The level of gluconeogenesis relative to glycolysis was indicated by the (13)C enrichment of trehalose C6 and alanine C3, both enrichments metabolically derived in the same manner. Insects starved after maintenance on the sucrose-free or low sucrose diets remained glucogenic. Insects on the high sucrose diet were not glucogenic, and subsequent starvation did not induce gluconeogenesis. The results indicate that pyruvate kinase plays a critical role in regulating the gluconeogenic/glycolytic balance, and that inhibition of pyruvate kinase is a principal regulatory event during induction of de novo trehalose synthesis. Gluconeogenesis failed to maintain homeostatic levels of blood trehalose, supporting the conclusion that blood sugar level may be important for mediating nutrient intake. Possible factors involved in the regulation of gluconeogenesis in insects are discussed. Copyright 2000 Academic Press.

Biosynthesis of inulin from sucrose using inulosucrase from Lactobacillus gasseri DSM 20604.

PubMed

Ni, Dawei; Zhu, Yingying; Xu, Wei; Bai, Yuxiang; Zhang, Tao; Mu, Wanmeng

2018-04-01

Inulin is composed of fructose residues connected by β-(2, 1) glycosidic linkages with many promising physiochemical and physiological properties. In this study, an inulin-producing inulosucrase gene from Lactobacillus gasseri DSM 20604 was cloned, expressed and purified. SDS-PAGE and gel filtration found that the recombinant inulosucrase is a monomeric protein with a molecular weight of 63KDa. The optimal pH for its sucrose hydrolysis and transfructosylation activities was pH 5.5. The optimal temperatures were measured to be 45, 25, and 35°C for sucrose hydrolysis, transfructosylation, and total activity, respectively. Biosynthesis studies showed that the optimal enzyme dosage was 4.5U/g sucrose. Higher sucrose concentrations immensely contributed to inulin biosynthesis; the inulin yield reached its maximum after 1.5h of reaction. Structural analyses of the polysaccharide produced by the recombinant enzyme from sucrose revealed that it is an inulin-type fructan with a molecular weight of 5.858×10 6 Da. Copyright © 2017 Elsevier B.V. All rights reserved.

A Novel Production Method for High-Fructose Glucose Syrup from Sucrose-Containing Biomass by a Newly Isolated Strain of Osmotolerant Meyerozyma guilliermondii.

PubMed

Khattab, Sadat Mohammad Rezq; Kodaki, Tsutomu

2016-04-28

One osmotolerant strain from among 44 yeast isolates was selected based on its growth abilities in media containing high concentrations of sucrose. This selected strain, named SKENNY, was identified as Meyerozyma guilliermondii by sequencing the internal transcribed spacer regions and partial D1/D2 large-subunit domains of the 26S ribosomal RNA. SK-ENNY was utilized to produce high-fructose glucose syrup (HFGS) from sucrose-containing biomass. Conversion rates to HFGS from 310-610 g/l of pure sucrose and from 75-310 g/l of sugar beet molasses were 73.5-94.1% and 76.2-91.1%, respectively. In the syrups produced, fructose yields were 89.4-100% and 96.5-100% and glucose yields were 57.6-82.5% and 55.3-79.5% of the theoretical values for pure sucrose and molasses sugars, respectively. This is the first report of employing M. guilliermondii for production of HFGS from sucrose-containing biomass.

EFFECTS OF SUGAR CONCENTRATION ON FECUNDITY, BITING BEHAVIOR AND SURVIVABILITY OF FEMALE AEDES (STEGOMYIA) ALBOPICTUS (SKUSE).

PubMed

Aiman, Muhammad; Kassim, Nur Faeza A; Jong, Zheng-Wei; Webb, Cameron E

2016-11-01

This study was conducted to better understand the effect of different sucrose concentrations on Aedes albopictus fecundity, biting behavior and survival. Laboratory strain Ae. albopictus females were raised at four different sucrose concentrations (10%, 30%, 50%, and 70%) and their fecundity, host biting on and survival rates were determined. Mosquitoes fed on high (50% or 70%) showed higher mean fecundity rate compared to those on low (10% or 30%) sucrose concentration, and had higher daily biting rate. On the other hand, mosquitoes fed on the low (10% or 30%) sucrose concentrations recorded higher survival rate. These results suggest female mosquitoes deficient in nutrient intake during sugar feeding may regain nutrients needed during blood feeding, whereas those fed on high sucrose concentration have high fecundity due to high biting rate but have low survivability due to low sucrose intake during sugar feeding. Thus, Ae. albopictus females have a capability to regulate their metabolic needs based on sugar nutrient availability.

Ovarian control of nectar collection in the honey bee (Apis mellifera).

PubMed

Siegel, Adam J; Freedman, Colin; Page, Robert E

2012-01-01

Honey bees are a model system for the study of division of labor. Worker bees demonstrate a foraging division of labor (DOL) by biasing collection towards carbohydrates (nectar) or protein (pollen). The Reproductive ground-plan hypothesis of Amdam et al. proposes that foraging DOL is regulated by the networks that controlled foraging behavior during the reproductive life cycle of honey bee ancestors. Here we test a proposed mechanism through which the ovary of the facultatively sterile worker impacts foraging bias. The proposed mechanism suggests that the ovary has a regulatory effect on sucrose sensitivity, and sucrose sensitivity impacts nectar loading. We tested this mechanism by measuring worker ovary size (ovariole number), sucrose sensitivity, and sucrose solution load size collected from a rate-controlled artificial feeder. We found a significant interaction between ovariole number and sucrose sensitivity on sucrose solution load size when using low concentration nectar. This supports our proposed mechanism. As nectar and pollen loading are not independent, a mechanism impacting nectar load size would also impact pollen load size.

Evaluation of absorbed dose in irradiated sugar-containing plant material (peony roots) by an ESR method

NASA Astrophysics Data System (ADS)

Yamaoki, Rumi; Kimura, Shojiro; Ohta, Masatoshi

2015-12-01

The relationship between electron spin resonance (ESR) signal intensity of irradiated plant materials and sugar content was investigated by spectral analysis using peony roots. A weak background signal near g=2.005 was observed in the roots. After a 10 kGy irradiation, the ESR line broadened and the intensity increased, and the spectral characteristics were similar to a typical spectrum of irradiated food containing crystalline sugars. The free radical concentration was nearly stable 30 days after irradiation. The spectrum of peony root 30 days after irradiation was simulated using the summation of the intensities of six assumed components: radical signals derived from (a) sucrose, (b) glucose, (c) fructose, (d) cellulose, (e) the background signal near g=2.005 and (f) unidentified component. The simulated spectra using the six components were in agreement with the observed sample spectra. The intensity of sucrose radical signal in irradiated samples increased proportionally up to 20 kGy. In addition, the intensity of sucrose radical signals was strongly correlated with the sucrose contents of the samples. The results showed that the radiation sensitivity of sucrose in peony roots was influenced little by other plant constituents. There was also a good correlation between the total area of the spectra and the sucrose content, because the sucrose content was higher than that of other sugars in the samples. In peony roots, estimation of the absorbed dose from the ESR signal intensity may be possible by a calibration method based on the sucrose content.

Effect of a long-term high-protein diet on survival, obesity development, and gut microbiota in mice.

PubMed

Kiilerich, Pia; Myrmel, Lene Secher; Fjære, Even; Hao, Qin; Hugenholtz, Floor; Sonne, Si Brask; Derrien, Muriel; Pedersen, Lone Møller; Petersen, Rasmus Koefoed; Mortensen, Alicja; Licht, Tine Rask; Rømer, Maria Unni; Vogel, Ulla Birgitte; Waagbø, Linn Jeanette; Giallourou, Natasa; Feng, Qiang; Xiao, Liang; Liu, Chuan; Liaset, Bjørn; Kleerebezem, Michiel; Wang, Jun; Madsen, Lise; Kristiansen, Karsten

2016-06-01

Female C57BL/6J mice were fed a regular low-fat diet or high-fat diets combined with either high or low protein-to-sucrose ratios during their entire lifespan to examine the long-term effects on obesity development, gut microbiota, and survival. Intake of a high-fat diet with a low protein/sucrose ratio precipitated obesity and reduced survival relative to mice fed a low-fat diet. By contrast, intake of a high-fat diet with a high protein/sucrose ratio attenuated lifelong weight gain and adipose tissue expansion, and survival was not significantly altered relative to low-fat-fed mice. Our findings support the notion that reduced survival in response to high-fat/high-sucrose feeding is linked to obesity development. Digital gene expression analyses, further validated by qPCR, demonstrated that the protein/sucrose ratio modulated global gene expression over time in liver and adipose tissue, affecting pathways related to metabolism and inflammation. Analysis of fecal bacterial DNA using the Mouse Intestinal Tract Chip revealed significant changes in the composition of the gut microbiota in relation to host age and dietary fat content, but not the protein/sucrose ratio. Accordingly, dietary fat rather than the protein/sucrose ratio or adiposity is a major driver shaping the gut microbiota, whereas the effect of a high-fat diet on survival is dependent on the protein/sucrose ratio. Copyright © 2016 the American Physiological Society.

Simultaneous contrast: evidence from licking microstructure and cross-solution comparisons.

PubMed

Dwyer, Dominic M; Lydall, Emma S; Hayward, Andrew J

2011-04-01

The microstructure of rats' licking responses was analyzed to investigate both "classic" simultaneous contrast (e.g., Flaherty & Largen, 1975) and a novel discrete-trial contrast procedure where access to an 8% test solution of sucrose was preceded by a sample of either 2%, 8%, or 32% sucrose (Experiments 1 and 2, respectively). Consumption of a given concentration of sucrose was higher when consumed alongside a low rather than high concentration comparison solution (positive contrast) and consumption of a given concentration of sucrose was lower when consumed alongside a high rather than a low concentration comparison solution (negative contrast). Furthermore, positive contrast increased the size of lick clusters while negative contrast decreased the size of lick clusters. Lick cluster size has a positive monotonic relationship with the concentration of palatable solutions and so positive and negative contrasts produced changes in lick cluster size that were analogous to raising or lowering the concentration of the test solution respectively. Experiment 3 utilized the discrete-trial procedure and compared contrast between two solutions of the same type (sucrose-sucrose or maltodextrin-maltodextrin) or contrast across solutions (sucrose-maltodextrin or maltodextrin-sucrose). Contrast effects on consumption were present, but reduced in size, in the cross-solution conditions. Moreover, lick cluster sizes were not affected at all by cross-solution contrasts as they were by same-solution contrasts. These results are consistent with the idea that simultaneous contrast effects depend, at least partially, on sensory mechanisms.

Maximizing Exosome Colloidal Stability Following Electroporation

PubMed Central

Hood, Joshua L.; Scott, Michael J.; Wickline, Samuel A.

2014-01-01

Development of exosome based semi-synthetic nanovesicles for diagnostic and therapeutic purposes requires novel approaches to load exosomes with cargo. Electroporation has previously been used to load exosomes with RNA. However, investigations into exosome colloidal stability following electroporation have not been considered. Herein, we report the development of a unique trehalose pulse media (TPM) that minimizes exosome aggregation following electroporation. Dynamic light scattering (DLS) and RNA absorbance were employed to determine the extent of exosome aggregation and electroextraction post electroporation in TPM compared to common PBS pulse media or sucrose pulse media (SPM). Use of TPM to disaggregate melanoma exosomes post electroporation was dependent on both exosome concentration and electric field strength. TPM maximized exosome dispersal post electroporation for both homogenous B16 melanoma and heterogeneous human serum derived populations of exosomes. Moreover, TPM enabled heavy cargo loading of melanoma exosomes with 5 nm superparamagnetic iron oxide nanoparticles (SPION5) while maintaining original exosome size and minimizing exosome aggregation as evidenced by transmission electron microscopy. Loading exosomes with SPION5 increased exosome density on sucrose gradients. This provides a simple, label free means to enrich exogenously modified exosomes and introduces the potential for MRI driven theranostic exosome investigations in vivo. PMID:24333249

Maximizing exosome colloidal stability following electroporation.

PubMed

Hood, Joshua L; Scott, Michael J; Wickline, Samuel A

2014-03-01

Development of exosome-based semisynthetic nanovesicles for diagnostic and therapeutic purposes requires novel approaches to load exosomes with cargo. Electroporation has previously been used to load exosomes with RNA. However, investigations into exosome colloidal stability following electroporation have not been considered. Herein, we report the development of a unique trehalose pulse media (TPM) that minimizes exosome aggregation following electroporation. Dynamic light scattering (DLS) and RNA absorbance were employed to determine the extent of exosome aggregation and electroextraction post electroporation in TPM compared to common PBS pulse media or sucrose pulse media (SPM). Use of TPM to disaggregate melanoma exosomes post electroporation was dependent on both exosome concentration and electric field strength. TPM maximized exosome dispersal post electroporation for both homogenous B16 melanoma and heterogeneous human serum-derived populations of exosomes. Moreover, TPM enabled heavy cargo loading of melanoma exosomes with 5nm superparamagnetic iron oxide nanoparticles (SPION5) while maintaining original exosome size and minimizing exosome aggregation as evidenced by transmission electron microscopy. Loading exosomes with SPION5 increased exosome density on sucrose gradients. This provides a simple, label-free means of enriching exogenously modified exosomes and introduces the potential for MRI-driven theranostic exosome investigations in vivo. Copyright © 2013 Elsevier Inc. All rights reserved.

Impact of structure and functionality of core polyol in highly functional biobased epoxy resins.

PubMed

Pan, Xiao; Webster, Dean C

2011-09-01

Highly functional biobased epoxy resins were prepared using dipentaerythritol (DPE), tripentaerythritol (TPE), and sucrose as core polyols that were substituted with epoxidized soybean oil fatty acids, and the impact of structure and functionality of the core polyol on the properties of the macromolecular resins and their epoxy-anhydride thermosets was explored. The chemical structures, functional groups, molecular weights, and compositions of epoxies were characterized using nuclear magnetic resonance (NMR) spectroscopy, Fourier-transform infrared (FTIR) spectroscopy, gel permeation chromatography (GPC), and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI MS). The epoxies were also studied for their bulk viscosity, intrinsic viscosity, and density. Crosslinked with dodecenyl succinic anhydride (DDSA), epoxy-anhydride thermosets were evaluated using differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA), tensile tests, and tests of coating properties. Epoxidized soybean oil (ESO) was used as a control. Overall, the sucrose-based thermosets exhibited the highest moduli, having the most rigid and ductile performance while maintaining the highest biobased content. DPE/TPE-based thermosets showed modestly better thermosetting performance than the control ESO thermoset. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

STUDIES ON ISOLATED NUCLEI. I. ISOLATION AND CHEMICAL CHARACTERIZATION OF A NUCLEAR FRACTION FROM GUINEA PIG LIVER.

PubMed

MAGGIO, R; SIEKEVITZ, P; PALADE, G E

1963-08-01

This article describes a method for the isolation of nuclei from guinea pig liver. It involves the homogenization of the tissue in 0.88 M sucrose-1.5 mM CaCl(2) followed by centrifugation in a discontinuous density gradient in which the upper phase is the homogenate and the lower phase is 2.2 M sucrose-0.5 mM CaCl(2). Based on DNA recovery, the isolated fraction contains 25 to 30 per cent of the nuclei of the original homogenate. Electron microscopical observations showed that approximately 88 per cent of the isolated nuclei come from liver cells (the rest from von Kupffer cells and leucocytes) and that approximately 90 per cent of the nuclei appear intact, with well preserved nucleoli, nucleoplasm, nuclear envelope, and pores. Cytoplasmic contamination is minimal and consists primarily of the nuclear envelope and its attached ribosomes. The nuclear fraction consists of approximately 22.3 per cent DNA, approximately 4.7 per cent RNA, and approximately 73 per cent protein, the DNA/RNA ratio being 4.7. Data on RNA extractibility by phosphate and salt and on the base composition of total nuclear RNA are included.

Diurnal periodicity of assimilate transport shapes resource allocation and whole-plant carbon balance.

PubMed

Brauner, Katrin; Birami, Benjamin; Brauner, Horst A; Heyer, Arnd G

2018-06-01

Whole-plant carbon balance comprises diurnal fluctuations of photosynthetic carbon gain and respiratory losses, as well as partitioning of assimilates between phototrophic and heterotrophic organs. Because it is difficult to access, the root system is frequently neglected in growth models, or its metabolism is rated based on generalizations from other organs. Here, whole-plant cuvettes were used for investigating total-plant carbon exchange with the environment over full diurnal cycles. Dynamics of primary metabolism and diurnally resolved phloem exudation profiles, as proxy of assimilate transport, were combined to obtain a full picture of resource allocation. This uncovered a strong impact of periodicity of inter-organ transport on the efficiency of carbon gain. While a sinusoidal fluctuation of the transport rate, with minor diel deflections, minimized respiratory losses in Arabidopsis wild-type plants, triangular or rectangular patterns of transport, found in mutants defective in either starch or sucrose metabolism, increased root respiration at the end or beginning of the day, respectively. Power spectral density and cross-correlation analysis revealed that only the rate of starch synthesis was strictly correlated to the rate of net photosynthesis in wild-type, while in a sucrose-phosphate synthase mutant (spsa1), this applied also to carboxylate synthesis, serving as an alternative carbon pool. In the starchless mutant of plastidial phospho-gluco mutase (pgm), none of these rates, but concentrations of sucrose and glucose in the root, followed the pattern of photosynthesis, indicating direct transduction of shoot sugar levels to the root. The results demonstrate that starch metabolism alone is insufficient to buffer diurnal fluctuations of carbon exchange. © 2018 The Authors The Plant Journal © 2018 John Wiley & Sons Ltd.

Is carbohydrate intake in the first years of life related to future risk of NCDs?

PubMed

Niinikoski, H; Ruottinen, S

2012-10-01

Studies on children's carbohydrate intake, especially fibre intake, and its associations with later health are rare. The current recommendations for fibre intake in children are based on average assumptions and data extrapolated from intakes in adults. Generally, increase in whole-grain consumption and decrease in sucrose intake are considered healthy. Due to fibre's high bulk volume however, excessive dietary fibre has been feared to decrease energy density have effects on growth, at least in developing countries and in children consuming very restricted diets. Furthermore, it has been speculated that if fats are reduced from the diet, it may become high in sucrose. In STRIP study, which is a long-term, randomized controlled trial designed to decrease the exposure of children to known risk factors of atherosclerosis, carbohydrate intakes have been investigated in detail in children aged 13 months to 9 years. The intervention was successful in decreasing saturated fat intake and cholesterol concentrations throughout childhood and adolescence. The study results also show that a higher than average fibre intake does not displace energy or disturb growth in children and that children with high fibre intake have better dietary quality than those with low fibre intake. Dietary fibre intake associated with lower serum total cholesterol concentrations whereas increases in total carbohydrate, sucrose and fructose intakes associated with increases in serum triglyceride concentrations. In conclusion, from the point of view of CHD risk factor prevention, efforts aiming at increasing the fibre intake while restricting that of refined sugar seem justified in the child population in developed countries. NCT00223600. Copyright © 2012 Elsevier B.V. All rights reserved.

Extracellular vesicles mediate signaling between the aqueous humor producing and draining cells in the ocular system

PubMed Central

Lerner, Natalie; Avissar, Sofia

2017-01-01

Purpose Canonical Wnt signaling is associated with glaucoma pathogenesis and intraocular pressure (IOP) regulation. Our goal was to gain insight into the influence of non-pigmented ciliary epithelium (NPCE)-derived exosomes on Wnt signaling by trabecular meshwork (TM) cells. The potential impact of exosomes on Wnt signaling in the ocular drainage system remains poorly understood. Methods Exosomes isolated from media collected from cultured NPCE cells by differential ultracentrifugation were characterized by dynamic light scattering (DLS), tunable resistive pulse sensing (TRPS), and nanoparticle tracking analysis (NTA), sucrose density gradient migration and transmission electron microscopy (TEM). The cellular target specificity of the NPCE-derived exosomes was investigated by confocal microscopy-based monitoring of the uptake of DiD-labeled exosomes over time, as compared to uptake by various cell lines. Changes in Wnt protein levels in TM cells induced by NPCE exosomes were evaluated by Western blot. Results Exosomes derived from NPCE cells were purified and detected as small rounded 50–140 nm membrane vesicles, as defined by DLS, NTA, TRPS and TEM. Western blot analysis indicated that the nanovesicles were positive for classic exosome markers, including Tsg101 and Alix. Isolated nanoparticles were found in sucrose density fractions typical of exosomes (1.118–1.188 g/mL sucrose). Using confocal microscopy, we demonstrated time-dependent specific accumulation of the NPCE-derived exosomes in NTM cells. Other cell lines investigated hardly revealed any exosome uptake. We further showed that exosomes induced changes in Wnt signaling protein expression in the TM cells. Western blot analysis further revealed decreased phosphorylation of GKS3β and reduced β-catenin levels. Finally, we found that treatment of NTM cells with exosomes resulted in a greater than 2-fold decrease in the level of β-catenin in the cytosolic fraction. In contrast, no remarkable difference in the amount of β-catenin in the nuclear fraction was noted, relative to the control. Conclusions The data suggest that NPCE cells release exosome-like vesicles and that these nanoparticles affect canonical Wnt signaling in TM cells. These findings may have therapeutic relevance since canonical Wnt pathway is involved in intra-ocular pressure regulation. Further understanding of NPCE-derived exosome-responsive signaling pathways may reveal new targets for pharmacological intervention within the drainage system as a target for glaucoma therapy. PMID:28241021

Extracellular vesicles mediate signaling between the aqueous humor producing and draining cells in the ocular system.

PubMed

Lerner, Natalie; Avissar, Sofia; Beit-Yannai, Elie

2017-01-01

Canonical Wnt signaling is associated with glaucoma pathogenesis and intraocular pressure (IOP) regulation. Our goal was to gain insight into the influence of non-pigmented ciliary epithelium (NPCE)-derived exosomes on Wnt signaling by trabecular meshwork (TM) cells. The potential impact of exosomes on Wnt signaling in the ocular drainage system remains poorly understood. Exosomes isolated from media collected from cultured NPCE cells by differential ultracentrifugation were characterized by dynamic light scattering (DLS), tunable resistive pulse sensing (TRPS), and nanoparticle tracking analysis (NTA), sucrose density gradient migration and transmission electron microscopy (TEM). The cellular target specificity of the NPCE-derived exosomes was investigated by confocal microscopy-based monitoring of the uptake of DiD-labeled exosomes over time, as compared to uptake by various cell lines. Changes in Wnt protein levels in TM cells induced by NPCE exosomes were evaluated by Western blot. Exosomes derived from NPCE cells were purified and detected as small rounded 50-140 nm membrane vesicles, as defined by DLS, NTA, TRPS and TEM. Western blot analysis indicated that the nanovesicles were positive for classic exosome markers, including Tsg101 and Alix. Isolated nanoparticles were found in sucrose density fractions typical of exosomes (1.118-1.188 g/mL sucrose). Using confocal microscopy, we demonstrated time-dependent specific accumulation of the NPCE-derived exosomes in NTM cells. Other cell lines investigated hardly revealed any exosome uptake. We further showed that exosomes induced changes in Wnt signaling protein expression in the TM cells. Western blot analysis further revealed decreased phosphorylation of GKS3β and reduced β-catenin levels. Finally, we found that treatment of NTM cells with exosomes resulted in a greater than 2-fold decrease in the level of β-catenin in the cytosolic fraction. In contrast, no remarkable difference in the amount of β-catenin in the nuclear fraction was noted, relative to the control. The data suggest that NPCE cells release exosome-like vesicles and that these nanoparticles affect canonical Wnt signaling in TM cells. These findings may have therapeutic relevance since canonical Wnt pathway is involved in intra-ocular pressure regulation. Further understanding of NPCE-derived exosome-responsive signaling pathways may reveal new targets for pharmacological intervention within the drainage system as a target for glaucoma therapy.

Irrigated sugarbeet sucrose content in relation to growing season climatic conditions in the northwest U.S.

USDA-ARS?s Scientific Manuscript database

The potential effects of changing climate on world food production have become a political and scientific focus. This study was conducted to investigate linkages between seasonal climatic conditions and sugarbeet sucrose content in southern Idaho and eastern Oregon. Sucrose content of irrigated suga...

Functionality of Inulin as a Sucrose Replacer in Cookie Baking

USDA-ARS?s Scientific Manuscript database

Inulin was evaluated as a sucrose replacer for healthy cookie production with benefits of low glycemic impact and prebiotic soluble fiber. Sucrose (as a reference) and three inulin products of different concentrations (as soluble fibers) were used to explore the effects of sugar-replacer type on so...

Limiting sucrose loss in Louisiana raw sugar factories: Are biocides necessary?

USDA-ARS?s Scientific Manuscript database

Sucrose deterioration takes place post-harvest in sugarcane, and is a significant problem for the sugar industry. In Louisiana, the majority of sucrose destruction occurs when cane is stock piled in mill yards and during overnight truck sleeper loads. Biocides are used in Louisiana raw sugarcane fac...

Survival and feeding rates of four aphid species (Hemiptera: Aphididae) on various sucrose concentrations in diets

USDA-ARS?s Scientific Manuscript database

Different concentrations of sucrose were used to investigate how survival and feeding was affected on four species of aphids (Hemiptera: Aphididae). Seven sucrose concentrations were evaluated in feeding chambers fitted with a parafilm membranes and infested with nymphs of Aphis glycines, Diuraphi...

Simultaneous determination of dextrose, sucrose, maltose, and lactose in sausage products by liquid chromatography.

PubMed

Ali, M S

1988-01-01

A liquid chromatographic (LC) method for the simultaneous determination of dextrose, sucrose, maltose, and lactose in sausage products has been developed. Dextrose, sucrose, maltose, and lactose are extracted from comminuted meat products with 52% ethanol. After filtration, the extracts are purified by passing them through a C18 Sep-Pak cartridge and 2 ion exchange resin Econo-columns in series. After concentration and filtration, extracts are analyzed by LC using a normal phase amino column and a differential refractometer detector. Homogeneously ground samples of cooked and fresh sausages are fortified with dextrose, sucrose, maltose, and lactose at 4 different concentrations. Average recovery for dextrose, sucrose, maltose, and lactose at all 4 levels of fortification was greater than 80% with a coefficient of variation less than 10%.

Moderate high fat diet increases sucrose self-administration in young rats.

PubMed

Figlewicz, Dianne P; Jay, Jennifer L; Acheson, Molly A; Magrisso, Irwin J; West, Constance H; Zavosh, Aryana; Benoit, Stephen C; Davis, Jon F

2013-02-01

We have previously reported that a moderately high fat diet increases motivation for sucrose in adult rats. In this study, we tested the motivational, neurochemical, and metabolic effects of the high fat diet in male rats transitioning through puberty, during 5-8 weeks of age. We observed that the high fat diet increased motivated responding for sucrose, which was independent of either metabolic changes or changes in catecholamine neurotransmitter metabolites in the nucleus accumbens. However, AGRP mRNA levels in the hypothalamus were significantly elevated. We demonstrated that increased activation of AGRP neurons is associated with motivated behavior, and that exogenous (third cerebroventricular) AGRP administration resulted in significantly increased motivation for sucrose. These observations suggest that increased expression and activity of AGRP in the medial hypothalamus may underlie the increased responding for sucrose caused by the high fat diet intervention. Finally, we compared motivation for sucrose in pubertal vs. adult rats and observed increased motivation for sucrose in the pubertal rats, which is consistent with previous reports that young animals and humans have an increased preference for sweet taste, compared with adults. Together, our studies suggest that background diet plays a strong modulatory role in motivation for sweet taste in adolescent animals. Published by Elsevier Ltd.

Transgenic cotton over-producing spinach sucrose phosphate synthase showed enhanced leaf sucrose synthesis and improved fiber quality under controlled environmental conditions.

PubMed

Haigler, Candace H; Singh, Bir; Zhang, Deshui; Hwang, Sangjoon; Wu, Chunfa; Cai, Wendy X; Hozain, Mohamed; Kang, Wonhee; Kiedaisch, Brett; Strauss, Richard E; Hequet, Eric F; Wyatt, Bobby G; Jividen, Gay M; Holaday, A Scott

2007-04-01

Prior data indicated that enhanced availability of sucrose, a major product of photosynthesis in source leaves and the carbon source for secondary wall cellulose synthesis in fiber sinks, might improve fiber quality under abiotic stress conditions. To test this hypothesis, a family of transgenic cotton plants (Gossypium hirsutum cv. Coker 312 elite) was produced that over-expressed spinach sucrose-phosphate synthase (SPS) because of its role in regulation of sucrose synthesis in photosynthetic and heterotrophic tissues. A family of 12 independent transgenic lines was characterized in terms of foreign gene insertion, expression of spinach SPS, production of spinach SPS protein, and development of enhanced extractable V (max) SPS activity in leaf and fiber. Lines with the highest V (max) SPS activity were further characterized in terms of carbon partitioning and fiber quality compared to wild-type and transgenic null controls. Leaves of transgenic SPS over-expressing lines showed higher sucrose:starch ratio and partitioning of (14)C to sucrose in preference to starch. In two growth chamber experiments with cool nights, ambient CO(2) concentration, and limited light below the canopy, the transgenic line with the highest SPS activity in leaf and fiber had higher fiber micronaire and maturity ratio associated with greater thickness of the cellulosic secondary wall.

Effects of Sucrose Stearate Addition on the Quality Improvement of Ready-To-Eat Samgyetang During Storage at 25℃

PubMed Central

2014-01-01

The effects of sucrose stearate at various concentrations (0.1%, 0.2%, and 0.3%, w/v) on the physico-chemical characteristics of ready-to-eat (RTE) Samgyetang were investigated during storage at 25℃ for 12 mon. Over the storage duration, the addition of sucrose stearate had no significant effects on the proximate composition of Samgyetang, including meat, broth, and porridge, or the hardness and spreadability of the porridge, although it resulted in significantly higher CIE L* values for the porridge. The CIE L* values of Samgyetang porridge with added sucrose stearate increased until 9 mon, while the control decreased until 6 mon, and the values for both changed insignificantly thereafter. The breast meat of Samgyetang treated with sucrose stearate showed higher percentages of polyunsaturated fatty acid after 3 mon and lower percentages of monounsaturated fatty acid after 6 mon compared to the control (p<0.05), while no significant differences were observed with the different sucrose stearate concentrations (p>0.05). The overall sensory acceptability scores were higher at sucrose stearate concentrations of 0.2% or 0.3% after 6 mon and at 0.1% after 9 mon compared to those of the control. PMID:26761503

Food selection in larval fruit flies: dynamics and effects on larval development

NASA Astrophysics Data System (ADS)

Schwarz, Sebastian; Durisko, Zachary; Dukas, Reuven

2014-01-01

Selecting food items and attaining a nutritionally balanced diet is an important challenge for all animals including humans. We aimed to establish fruit fly larvae ( Drosophila melanogaster) as a simple yet powerful model system for examining the mechanisms of specific hunger and diet selection. In two lab experiments with artificial diets, we found that larvae deprived of either sucrose or protein later selectively fed on a diet providing the missing nutrient. When allowed to freely move between two adjacent food patches, larvae surprisingly preferred to settle on one patch containing yeast and ignored the patch providing sucrose. Moreover, when allowed to move freely between three patches, which provided either yeast only, sucrose only or a balanced mixture of yeast and sucrose, the majority of larvae settled on the yeast-plus-sucrose patch and about one third chose to feed on the yeast only food. While protein (yeast) is essential for development, we also quantified larval success on diets with or without sucrose and show that larvae develop faster on diets containing sucrose. Our data suggest that fruit fly larvae can quickly assess major nutrients in food and seek a diet providing a missing nutrient. The larvae, however, probably prefer to quickly dig into a single food substrate for enhanced protection over achieving an optimal diet.

Stimulation of mitochondrial pyruvate metabolism and citrulline synthesis by dexamethasone. Effect of isolation and incubation media.

PubMed Central

Martin, A D; Titheradge, M A

1984-01-01

Hepatic mitochondria isolated in 0.3 M-sucrose or 0.3 M-mannitol from rats treated for 3h with dexamethasone displayed stimulated rates of pyruvate carboxylation and decarboxylation and citrulline synthesis when compared with organelles from control animals. Mitochondria isolated in mannitol also displayed elevated rates of pyruvate carboxylation and decarboxylation when compared with those isolated in sucrose, and this stimulation was shown to be independent of the lengthy isolation procedure. Citrulline synthesis proceeded at similar rates in mitochondria isolated in either sugar. The concentration of exchangeable adenine nucleotides was identical in mitochondria isolated in sucrose or mannitol, suggesting that those prepared in the former sugar are not more permeable to metabolites than those prepared in the latter. The matrix volume of mitochondria isolated in mannitol was greater than that of mitochondria isolated in sucrose, and the effect of mannitol on pyruvate metabolism was mimicked by swelling the organelles in hypo-osmotic sucrose. Measurements of the extra-matrix volume by using [14C]sucrose or [14C]mannitol suggest that mannitol can permeate mitochondria to a greater extent than can sucrose. The possibility that mannitol elicits its effect by entering the mitochondrial matrix and so initiating swelling is discussed. PMID:6433898

Transepithelial leak in Barrett's esophagus patients: The role of proton pump inhibitors

PubMed Central

Farrell, Christopher; Morgan, Melissa; Tully, Owen; Wolov, Kevin; Kearney, Keith; Ngo, Benjamin; Mercogliano, Giancarlo; Thornton, James J; Valenzano, Mary Carmen; Mullin, James M

2012-01-01

AIM: To determine if the observed paracellular sucrose leak in Barrett’s esophagus patients is due to their proton pump inhibitor (PPI) use. METHODS: The in vivo sucrose permeability test was administered to healthy controls, to Barrett’s patients and to non-Barrett’s patients on continuous PPI therapy. Degree of leak was tested for correlation with presence of Barrett’s, use of PPIs, and length of Barrett’s segment and duration of PPI use. RESULTS: Barrett’s patients manifested a near 3-fold greater, upper gastrointestinal sucrose leak than healthy controls. A decrease of sucrose leak was observed in Barrett’s patients who ceased PPI use for 7 d. Although initial introduction of PPI use (in a PPI-naïve population) results in dramatic increase in sucrose leak, long-term, continuous PPI use manifested a slow spontaneous decline in leak. The sucrose leak observed in Barrett’s patients showed no correlation to the amount of Barrett’s tissue present in the esophagus. CONCLUSION: Although future research is needed to determine the degree of paracellular leak in actual Barrett’s mucosa, the relatively high degree of leak observed with in vivo sucrose permeability measurement of Barrett’s patients reflects their PPI use and not their Barrett’s tissue per se. PMID:22719187

Frequency of sucrose exposure on the cariogenicity of a biofilm-caries model

PubMed Central

Díaz-Garrido, Natalia; Lozano, Carla; Giacaman, Rodrigo A.

2016-01-01

Objective: Although sucrose is considered the most cariogenic carbohydrate in the human diet, the question of how many exposures are needed to induce damage on the hard dental tissues remains unclear. To approach this question, different frequencies of daily sucrose exposure were tested on a relevant biological caries model. Materials and Methods: Biofilms of the Streptococcus mutans were formed on enamel slabs and exposed to cariogenic challenges with 10% sucrose for 5 min at 0, 1, 3, 5, 8, or 10 times per day. After 5 days, biofilms were retrieved to analyze biomass, protein content, viable bacteria, and polysaccharide formation. Enamel demineralization was evaluated by percentage of microhardness loss (percentage surface hardness loss [%SHL]). Results: Biomass, protein content, polysaccharide production, acidogenicity of the biofilm, and %SHL proportionally increased with the number of daily exposures to sucrose (P < 0.05). One daily sucrose exposure was enough to induce 20% more demineralization than the negative unexposed control. Higher frequencies induced greater demineralization and more virulent biofilms, but eight and ten exposures were not different between them in most of the analyzed variables (P > 0.05). Conclusions: Higher sucrose exposure seems to increase cariogenicity, in a frequency-dependent manner, by the modification of bacterial virulent properties. PMID:27403051

Repetitive postprandial hyperglycemia increases cardiac ischemia/reperfusion injury: prevention by the alpha-glucosidase inhibitor acarbose.

PubMed

Frantz, Stefan; Calvillo, Laura; Tillmanns, Jochen; Elbing, Inka; Dienesch, Charlotte; Bischoff, Hilmar; Ertl, Georg; Bauersachs, Johann

2005-04-01

Protective effects of the alpha-glucosidase inhibitor acarbose have been reported for various diabetic complications. In the STOP-NIDDM study, even patients without overt diabetes, but with impaired glucose tolerance, had a reduction in cardiovascular events when treated with acarbose. Therefore, we investigated the effect of repetitive postprandial hyperglycemia on the cardiac ischemia/reperfusion injury in vivo. Mice were treated daily by single applications of placebo, sucrose (4 g/kg body weight), or sucrose + acarbose (10 mg/kg body weight) by gavage for 7 days. Acarbose treatment significantly reduced the sucrose-induced increase in plasma glucose concentration. Subsequently, animals underwent 30 min of ischemia by coronary artery ligation and 24 h of reperfusion in vivo. In the sucrose group, ischemia/reperfusion damage was significantly increased (infarct/area at risk, placebo vs. sucrose, 38.8+/-7.5% vs. 62.2+/-4.8%, P<0.05). This was prevented by acarbose treatment (infarct/area at risk 30.7+/-7.2%). While myocardial inflammation was similar in all groups, oxidative stress as indicated by a significant increase in lipid peroxides was enhanced in the sucrose, but not in the sucrose + acarbose group. In summary, repetitive postprandial hyperglycemia increases ischemia/reperfusion damage. This effect can be prevented by treatment with the alpha-glucosidase inhibitor acarbose.

Effect of sucrose availability and pre-running on the intrinsic value of wheel running as an operant and a reinforcing consequence.

PubMed

Belke, Terry W; Pierce, W David

2014-03-01

The current study investigated the effect of motivational manipulations on operant wheel running for sucrose reinforcement and on wheel running as a behavioral consequence for lever pressing, within the same experimental context. Specifically, rats responded on a two-component multiple schedule of reinforcement in which lever pressing produced the opportunity to run in a wheel in one component of the schedule (reinforcer component) and wheel running produced the opportunity to consume sucrose solution in the other component (operant component). Motivational manipulations involved removal of sucrose contingent on wheel running and providing 1h of pre-session wheel running. Results showed that, in opposition to a response strengthening view, sucrose did not maintain operant wheel running. The motivational operations of withdrawing sucrose or providing pre-session wheel running, however, resulted in different wheel-running rates in the operant and reinforcer components of the multiple schedule; this rate discrepancy revealed the extrinsic reinforcing effects of sucrose on operant wheel running, but also indicated the intrinsic reinforcement value of wheel running across components. Differences in wheel-running rates between components were discussed in terms of arousal, undermining of intrinsic motivation, and behavioral contrast. Copyright © 2013 Elsevier B.V. All rights reserved.

LFSPMC: Linear feature selection program using the probability of misclassification

NASA Technical Reports Server (NTRS)

Guseman, L. F., Jr.; Marion, B. P.

1975-01-01

The computational procedure and associated computer program for a linear feature selection technique are presented. The technique assumes that: a finite number, m, of classes exists; each class is described by an n-dimensional multivariate normal density function of its measurement vectors; the mean vector and covariance matrix for each density function are known (or can be estimated); and the a priori probability for each class is known. The technique produces a single linear combination of the original measurements which minimizes the one-dimensional probability of misclassification defined by the transformed densities.

Stochastic sediment property inversion in Shallow Water 06.

PubMed

Michalopoulou, Zoi-Heleni

2017-11-01

Received time-series at a short distance from the source allow the identification of distinct paths; four of these are direct, surface and bottom reflections, and sediment reflection. In this work, a Gibbs sampling method is used for the estimation of the arrival times of these paths and the corresponding probability density functions. The arrival times for the first three paths are then employed along with linearization for the estimation of source range and depth, water column depth, and sound speed in the water. Propagating densities of arrival times through the linearized inverse problem, densities are also obtained for the above parameters, providing maximum a posteriori estimates. These estimates are employed to calculate densities and point estimates of sediment sound speed and thickness using a non-linear, grid-based model. Density computation is an important aspect of this work, because those densities express the uncertainty in the inversion for sediment properties.

Effects of nutritional state, aging and high chronic intake of sucrose on brain protein synthesis in rats: modulation of it by rutin and other micronutrients.

PubMed

Gatineau, Eva; Cluzet, Stéphanie; Krisa, Stéphanie; Papet, Isabelle; Migne, Carole; Remond, Didier; Dardevet, Dominique; Polakof, Sergio; Richard, Tristan; Mosoni, Laurent

2018-05-23

Little is still known about brain protein synthesis. In order to increase our knowledge of it, we aimed to modulate brain protein synthesis rates through aging, variations in nutritional state (fed state vs. fasted state), high sucrose diet and micronutrient supplementation. Four groups of 16 month-old male rats were fed for five months with a diet containing either 13% or 62% sucrose (wheat starch was replaced with sucrose), supplemented or not with rutin (5 g kg-1 diet), vitamin E (4×), A (2×), D (5×), selenium (10×) and zinc (+44%) and compared with an adult control group. We measured cerebellum protein synthesis and hippocampus gene expression of antioxidant enzymes, inflammatory cytokines and transcription factors. We showed that cerebellum protein synthesis was unchanged by the nutritional state, decreased during aging (-8%), and restored to the adult level by micronutrient supplementation. Sucrose diet did not change protein synthesis but reduced the protein content. Micronutrient supplementation had no effect in sucrose fed rats. Hippocampus gene expressions were affected by age (an increase of TNF-α), sucrose treatment (an increase of IL-1β and IL-6), and micronutrient supplementation (a decrease of heme oxygenase, catalase, glutathione peroxidase, TNF-α, and Nrf2). We noted that cerebellum protein synthesis and hippocampus TNF-α gene expression were modulated by the same factors: they were affected by aging and micronutrient supplementation and unchanged by feeding and by high sucrose diet.

Antisense inhibition of tomato fruit sucrose synthase decreases fruit setting and the sucrose unloading capacity of young fruit.

PubMed Central

D'Aoust, M A; Yelle, S; Nguyen-Quoc, B

1999-01-01

The role of sucrose synthase (SuSy) in tomato fruit was studied in transgenic tomato (Lycopersicon esculentum) plants expressing an antisense fragment of fruit-specific SuSy RNA (TOMSSF) under the control of the cauliflower mosaic virus 35S promoter. Constitutive expression of the antisense RNA markedly inhibited SuSy activity in flowers and fruit pericarp tissues. However, inhibition was only slight in the endosperm and was undetectable in the embryo, shoot, petiole, and leaf tissues. The activity of sucrose phosphate synthase decreased in parallel with that of SuSy, but acid invertase activity did not increase in response to the reduced SuSy activity. The only effect on the carbohydrate content of young fruit was a slight reduction in starch accumulation. The in vitro sucrose import capacity of fruits was not reduced by SuSy inhibition at 23 days after anthesis, and the rate of starch synthesized from the imported sucrose was not lessened even when SuSy activity was decreased by 98%. However, the sucrose unloading capacity of 7-day-old fruit was substantially decreased in lines with low SuSy activity. In addition, the SuSy antisense fruit from the first week of flowering had a slower growth rate. A reduced fruit set, leading to markedly less fruit per plant at maturity, was observed for the plants with the least SuSy activity. These results suggest that SuSy participates in the control of sucrose import capacity of young tomato fruit, which is a determinant for fruit set and development. PMID:10590167

Tarsal taste neuron activity and proboscis extension reflex in response to sugars and amino acids in Helicoverpa armigera (Hubner).

PubMed

Zhang, Yun-Feng; van Loon, Joop J A; Wang, Chen-Zhu

2010-08-15

In adult female Helicoverpa armigera (Hübner), the fifth tarsomere of the prothoracic legs bears 14 gustatory trichoid chemosensilla. These chemosensilla were characterized through electrophysiological experiments by stimulating with sucrose, glucose, fructose, maltose, myo-inositol and 20 common amino acids. In electrophysiological recordings from nine sensilla, responses were obtained to certain compounds tested at 100 mmol l(-1), and the response spectra differed from broad to narrow. The four sugars excited the same receptor neuron in sensillum a and sensillum b; sucrose and myo-inositol, sucrose and lysine, myo-inositol and lysine excited two different receptor neurons respectively in sensillum a; fructose and lysine excited two different receptor neurons in sensillum n. Furthermore, the four sugars, myo-inositol and lysine all elicited concentration-dependent electrophysiological responses. These six compounds also induced the proboscis extension reflex (PER) followed by ingestion of the solution when they were applied on the tarsi. Lysine and sucrose caused the strongest electrophysiological responses. However, sucrose had the strongest stimulatory effect on the PER whereas lysine had the weakest. Mixtures of sucrose with the other sugars or with lysine had a similar stimulatory effect on the PER as sucrose alone. The electrophysiological and behavioural responses caused by a range of sucrose concentrations were positively correlated. We conclude that the tarsal gustatory sensilla play an essential role in perceiving sugars available in floral nectar and provide chemosensory information determining feeding behaviour. Tarsal taste-receptor-neuron responses to lysine are implicated in oviposition behaviour.

Trial of Music, Sucrose, and Combination Therapy for Pain Relief during Heel Prick Procedures in Neonates.

PubMed

Shah, Swapnil R; Kadage, Shahajahan; Sinn, John

2017-11-01

To compare the effectiveness of music, oral sucrose, and combination therapy for pain relief in neonates undergoing a heel prick procedure. This randomized, controlled, blinded crossover clinical trial included stable neonates >32 weeks of postmenstrual age. Each neonate crossed over to all 3 interventions in random order during consecutive heel pricks. A video camera on mute mode recorded facial expressions, starting 2 minutes before until 7 minutes after the heel prick. The videos were later analyzed using the Premature Infant Pain Profile-Revised (PIPP-R) scale once per minute by 2 independent assessors, blinded to the intervention. The PIPP-R scores were compared between treatment groups using Friedman test. For the 35 participants, the postmenstrual age was 35 weeks (SD, 2.3) with an average weight of 2210 g (SD, 710). The overall median PIPP-R scores following heel prick over 6 minutes were 4 (IQR 0-6), 3 (IQR 0-6), and 1 (IQR 0-3) for the music, sucrose, and combination therapy interventions, respectively. The PIPP-R scores were significantly lower at all time points after combination therapy compared with the groups given music or sucrose alone. There was no difference in PIPP-R scores between the music and sucrose groups. In relatively stable and mature neonates, the combination of music therapy with sucrose provided better pain relief during heel prick than when sucrose or music was used alone. Recorded music in isolation had a similar effect to the current gold standard of oral sucrose. www.anzctr.org.au ACTRN12615000271505. Copyright © 2017 Elsevier Inc. All rights reserved.

A Precision Microbiome Approach Using Sucrose for Selective Augmentation of Staphylococcus epidermidis Fermentation against Propionibacterium acnes

PubMed Central

Wang, Yanhan; Kao, Ming-Shan; Yu, Jinghua; Huang, Stephen; Marito, Shinta; Gallo, Richard L.; Huang, Chun-Ming

2016-01-01

Acne dysbiosis happens when there is a microbial imbalance of the over-growth of Propionibacterium acnes (P. acnes) in the acne microbiome. In our previous study, we demonstrated that Staphylococcus epidermidis (S. epidermidis, a probiotic skin bacterium) can exploit glycerol fermentation to produce short-chain fatty acids (SCFAs) which have antimicrobial activities to suppress the growth of P. acnes. Unlike glycerol, sucrose is chosen here as a selective fermentation initiator (SFI) that can specifically intensify the fermentation activity of S. epidermidis, but not P. acnes. A co-culture of P. acnes and fermenting S. epidermidis in the presence of sucrose significantly led to a reduction in the growth of P. acnes. The reduction was abolished when P. acnes was co-cultured with non-fermenting S. epidermidis. Results from nuclear magnetic resonance (NMR) analysis revealed four SCFAs (acetic acid, butyric acid, lactic acid, and succinic acid) were detectable in the media of S. epidermidis sucrose fermentation. To validate the interference of S. epidermidis sucrose fermentation with P. acnes, mouse ears were injected with both P. acnes and S. epidermidis plus sucrose or phosphate buffered saline (PBS). The level of macrophage-inflammatory protein-2 (MIP-2) and the number of P. acnes in ears injected with two bacteria plus sucrose were considerably lower than those in ears injected with two bacteria plus PBS. Our results demonstrate a precision microbiome approach by using sucrose as a SFI for S. epidermidis, holding future potential as a novel modality to equilibrate dysbiotic acne. PMID:27834859

A Precision Microbiome Approach Using Sucrose for Selective Augmentation of Staphylococcus epidermidis Fermentation against Propionibacterium acnes.

PubMed

Wang, Yanhan; Kao, Ming-Shan; Yu, Jinghua; Huang, Stephen; Marito, Shinta; Gallo, Richard L; Huang, Chun-Ming

2016-11-09

Acne dysbiosis happens when there is a microbial imbalance of the over-growth of Propionibacterium acne s ( P. acnes ) in the acne microbiome. In our previous study, we demonstrated that Staphylococcus epidermidis ( S. epidermidis , a probiotic skin bacterium) can exploit glycerol fermentation to produce short-chain fatty acids (SCFAs) which have antimicrobial activities to suppress the growth of P. acnes . Unlike glycerol, sucrose is chosen here as a selective fermentation initiator (SFI) that can specifically intensify the fermentation activity of S. epidermidis , but not P. acnes . A co-culture of P. acnes and fermenting S. epidermidis in the presence of sucrose significantly led to a reduction in the growth of P. acnes . The reduction was abolished when P. acnes was co-cultured with non-fermenting S. epidermidis . Results from nuclear magnetic resonance (NMR) analysis revealed four SCFAs (acetic acid, butyric acid, lactic acid, and succinic acid) were detectable in the media of S. epidermidis sucrose fermentation. To validate the interference of S. epidermidis sucrose fermentation with P. acnes , mouse ears were injected with both P. acnes and S. epidermidis plus sucrose or phosphate buffered saline (PBS). The level of macrophage-inflammatory protein-2 (MIP-2) and the number of P. acnes in ears injected with two bacteria plus sucrose were considerably lower than those in ears injected with two bacteria plus PBS. Our results demonstrate a precision microbiome approach by using sucrose as a SFI for S. epidermidis , holding future potential as a novel modality to equilibrate dysbiotic acne.

Effects of the naturally-occurring disaccharides, palatinose and sucrose, on incretin secretion in healthy non-obese subjects.

PubMed

Maeda, Aya; Miyagawa, Jun-Ichiro; Miuchi, Masayuki; Nagai, Etsuko; Konishi, Kosuke; Matsuo, Toshihiro; Tokuda, Masaru; Kusunoki, Yoshiki; Ochi, Humihiro; Murai, Kazuki; Katsuno, Tomoyuki; Hamaguchi, Tomoya; Harano, Yutaka; Namba, Mitsuyoshi

2013-05-06

Incretins might play some pathophysiological role in glucose metabolism in diabetes and obesity; it is not clear whether or not the amount and the pattern of incretin secretion vary with different types of sugars. To evaluate the effect of two types of disaccharides on glucose metabolism and the kinetics of incretin secretion, plasma levels were measured after palatinose or sucrose ingestion in non-obese healthy participants. The study was carried out on healthy participants who were given a solution containing 50 g of palatinose or sucrose for ingestion. Blood samples were obtained before loading and after ingestion. Insulin, glucagon and incretins hormones were measured by the enzyme-linked immunosorbent assay method. When the data were compared between palatinose and sucrose ingestion, both plasma glucose values at 15, 30 and 60 min, and plasma insulin values at 15 and 30 min after palatinose loading were significantly lower than those after sucrose loading. Plasma levels of total glucose-dependent insulinotropic polypeptide at 15-90 min after palatinose loading were significantly lower than those after sucrose loading. Plasma levels of total and active glucagon-like peptide-1 at 90 min and the area under the curve (60-120 min) of the total glucagon-like peptide-1 were significantly higher with palatinose-loading than with sucrose loading. Compared with sucrose, palatinose appears to have a more favorable effect on glucose metabolism and protection of pancreatic islets as a result of less hyperglycemic and hyperinsulinemic potency.

The tarsal taste of honey bees: behavioral and electrophysiological analyses

PubMed Central

de Brito Sanchez, Maria Gabriela; Lorenzo, Esther; Su, Songkun; Liu, Fanglin; Zhan, Yi; Giurfa, Martin

2014-01-01

Taste plays a crucial role in the life of honey bees as their survival depends on the collection and intake of nectar and pollen, and other natural products. Here we studied the tarsal taste of honey bees through a series of behavioral and electrophysiological analyses. We characterized responsiveness to various sweet, salty and bitter tastants delivered to gustatory sensilla of the fore tarsi. Behavioral experiments showed that stimulation of opposite fore tarsi with sucrose and bitter substances or water yielded different outcomes depending on the stimulation sequence. When sucrose was applied first, thereby eliciting proboscis extension, no bitter substance could induce proboscis retraction, thus suggesting that the primacy of sucrose stimulation induced a central excitatory state. When bitter substances or water were applied first, sucrose stimulation could still elicit proboscis extension but to a lower level, thus suggesting central inhibition based on contradictory gustatory input on opposite tarsi. Electrophysiological experiments showed that receptor cells in the gustatory sensilla of the tarsomeres are highly sensitive to saline solutions at low concentrations. No evidence for receptors responding specifically to sucrose or to bitter substances was found in these sensilla. Receptor cells in the gustatory sensilla of the claws are highly sensitive to sucrose. Although bees do not possess dedicated bitter-taste receptors in the tarsi, indirect bitter detection is possible because bitter tastes inhibit sucrose receptor cells of the claws when mixed with sucrose solution. By combining behavioral and electrophysiological approaches, these results provide the first integrative study on tarsal taste detection in the honey bee. PMID:24550801

Agrometeorological parameters for prediction of the maturation period of Arabica coffee cultivars

NASA Astrophysics Data System (ADS)

Pezzopane, José Ricardo Macedo; Salva, Terezinha de Jesus Garcia; de Lima, Valéria Bittencourt; Fazuoli, Luiz Carlos

2012-09-01

The objective of this study was to determine the harvest period of coffee fruits based on the relationship between agrometeorological parameters and sucrose accumulation in the seeds. Over the crop years 2004/2005 and 2006/2007, from 150 days after flowering (DAF) onwards, samples of 50 fruits of cultivars Mundo Novo IAC 376-4, Obatã IAC 1669-20 and Catuaí Vermelho IAC 144 were collected from coffee trees located in Campinas, Brazil. The endosperm of the fruits was freeze-dried, ground and analyzed for sucrose content by high-performance liquid chromatography. A weather station provided data to calculate the accumulated growing degree-day (GDD) units, and the reference (ETo) and actual (ETr) evapotranspiration rates. The results showed that the highest rates of sucrose accumulation occurred at the transition from the cane-green to the cherry phenological stage. Models for the estimation of sucrose content during maturation based on meteorological variables exhibited similar or better performance than the DAF variable, with better results for the variables GDD and ETo. The Mundo Novo cultivar reached the highest sucrose level in the endosperm after 2,790 GDD, while cultivar Catuaí attained its maximum sucrose concentration after the accumulated evapotranspiration rate has reached a value of 870 mm. As for cultivar Obatã, the maximum sucrose concentration was predicted with the same degree of accuracy using any of the parameters investigated. For the Obatã cultivar, the values of the variables calculated for the maximum sucrose concentration to be reached were 249 DAF, 3,090 GDD, 1,020 ETo and 900 ETr.

Sucrose acceptance and different forms of associative learning of the honey bee (apis mellifera L.) in the field and laboratory.

PubMed

Mujagic, Samir; Sarkander, Jana; Erber, Barbara; Erber, Joachim

2010-01-01

The experiments analyze different forms of learning and 24-h retention in the field and in the laboratory in bees that accept sucrose with either low (/=30% or >/=50%) concentrations. In the field we studied color learning at a food site and at the hive entrance. In the laboratory olfactory conditioning of the proboscis extension response (PER) was examined. In the color learning protocol at a feeder, bees with low sucrose acceptance thresholds (/=50%). Retention after 24 h is significantly different between the two groups of bees and the choice reactions converge. Bees with low and high acceptance thresholds in the field show no differences in the sucrose sensitivity PER tests in the laboratory. Acceptance thresholds in the field are thus a more sensitive behavioral measure than PER responsiveness in the laboratory. Bees with low acceptance thresholds show significantly better acquisition and 24-h retention in olfactory learning in the laboratory compared to bees with high thresholds. In the learning protocol at the hive entrance bees learn without sucrose reward that a color cue signals an open entrance. In this experiment, bees with high sucrose acceptance thresholds showed significantly better learning and reversal learning than bees with low thresholds. These results demonstrate that sucrose acceptance thresholds affect only those forms of learning in which sucrose serves as the reward. The results also show that foraging behavior in the field is a good predictor for learning behavior in the field and in the laboratory.

The tarsal taste of honey bees: behavioral and electrophysiological analyses.

PubMed

de Brito Sanchez, Maria Gabriela; Lorenzo, Esther; Su, Songkun; Liu, Fanglin; Zhan, Yi; Giurfa, Martin

2014-01-01

Taste plays a crucial role in the life of honey bees as their survival depends on the collection and intake of nectar and pollen, and other natural products. Here we studied the tarsal taste of honey bees through a series of behavioral and electrophysiological analyses. We characterized responsiveness to various sweet, salty and bitter tastants delivered to gustatory sensilla of the fore tarsi. Behavioral experiments showed that stimulation of opposite fore tarsi with sucrose and bitter substances or water yielded different outcomes depending on the stimulation sequence. When sucrose was applied first, thereby eliciting proboscis extension, no bitter substance could induce proboscis retraction, thus suggesting that the primacy of sucrose stimulation induced a central excitatory state. When bitter substances or water were applied first, sucrose stimulation could still elicit proboscis extension but to a lower level, thus suggesting central inhibition based on contradictory gustatory input on opposite tarsi. Electrophysiological experiments showed that receptor cells in the gustatory sensilla of the tarsomeres are highly sensitive to saline solutions at low concentrations. No evidence for receptors responding specifically to sucrose or to bitter substances was found in these sensilla. Receptor cells in the gustatory sensilla of the claws are highly sensitive to sucrose. Although bees do not possess dedicated bitter-taste receptors in the tarsi, indirect bitter detection is possible because bitter tastes inhibit sucrose receptor cells of the claws when mixed with sucrose solution. By combining behavioral and electrophysiological approaches, these results provide the first integrative study on tarsal taste detection in the honey bee.

Effect of calcium glycerophosphate on demineralization in an in vitro biofilm model.

PubMed

Lynch, R J M; ten Cate, J M

2006-01-01

The aim was to investigate the anti-caries properties of calcium glycerophosphate (CaGP) using an in vitro bacterial flow cell model. Four flow cells, inoculated from a chemostat containing a seven-organism bacterial consortium, were pulsed with sucrose twice daily, to provide an acidic challenge and pH-cycling conditions. Blocks of enamel and dentine were mounted in each flow cell. In a study on the effect of CaGP concentration, CaGP was pulsed into three of the flow cells, at the same time as the sucrose, to give concentrations of 0.10, 0.25 and 0.50%. Water was pulsed into the fourth flow cell with the sucrose. Microradiography revealed a significant dose response of decreasing demineralization as CaGP concentration increased. Reductions at 0.25 and 0.5% were significant when compared to the control. A second study investigated the effect of timing of CaGP pulsing, relative to sucrose, on enamel and dentine demineralization. CaGP (flow cell concentration 0.2%), was pulsed 1 h before, during or 1 h after the sucrose pulse; a water control was employed. In enamel, pulsing CaGP before the sucrose reduced demineralization significantly compared to concurrent pulsing, which in turn gave a significant reduction compared to pulsing after sucrose, which did not reduce demineralization significantly compared to the water control. In dentine, CaGP reduced demineralization significantly only when pulsed before the sucrose. The findings suggest that in vivo, the anti-caries potential of CaGP may be greater if it is applied before a cariogenic challenge. Copyright (c) 2006 S. Karger AG, Basel.

Postharvest respiration rate and sucrose concentration of Rhizoctonia-infected sugar beet roots

USDA-ARS?s Scientific Manuscript database

Rhizoctonia crown and root rot (RCRR), caused by Rhizoctonia solani AG 2-2, is a common root disease on sugar beet that reduces yield and sucrose during the growing season and causes further losses by increasing respiration and reducing sucrose content during storage. The industry needs to identify...

Temporal and spacial aspects of root and stem sucrose metabolism in loblolly pine trees

Treesearch

Shi-Jean S. Sung; Paul P. Kormanik; C.C. Black

1996-01-01

We studied root and stem sucrose metabolism in trees excavated from a 9-year-old artificially regenerated loblolly pine (Pinus taeda L.) plantation. Sucrose synthase (SS) activities in stem and taproot vascular cambial tissues followed similar seasonal patterns until they peaked during September. After September, stem SS activity disappeared...

Role of plaque in the clearance of salivary sucrose and its influence on salivary ph.

PubMed

Kumar, A; Hedge, R; Dixit, U

2011-01-01

The prevalence of dental caries in children, in India, is higher than many of the industrialized countries. The sugar most commonly associated with dental caries is sucrose, as the microorganisms in the dental plaque have the ability to convert this dietary constituent into various organic acids. This study was conducted to study the effect of the presence of plaque on the salivary clearance of sucrose and to study the effect of the presence of plaque on salivary pH, following sucrose clearance. Salivary sucrose determination was done by using the anthrone technique. A Digital MHOS pH meter estimated the salivary pH. Presence of plaque increased the salivary sucrose clearance time and decreased the salivary pH at various time intervals. The microbial etiology of dental caries is the dynamic relationship among the dental plaque microbiota, dietary carbohydrates, saliva and pH lowering, and the cariogenic potential of the dental plaque. Caries occur preferentially in the dentition sites characterized by high exposure to carbohydrate and diminished salivary effect.

Milk iron content in breast-feeding mothers after administration of intravenous iron sucrose complex.

PubMed

Breymann, Christian; von Seefried, Bettina; Stahel, Michele; Geisser, Peter; Canclini, Camillo

2007-01-01

To study the transfer of parenteral iron sucrose into maternal milk in the postpartum period. Ten healthy lactating mothers with functional iron deficiency 2-3 days after delivery received 100 mg intravenous iron sucrose and were observed together with a control group (n=5) without iron treatment during four days. Milk samples were taken before the treatment and every day afterwards. Mean milk iron levels at baseline were 0.43 and 0.46 mg/kg in the treatment and control group and decreased until the end of observation in both groups by 0.11 mg/kg. No significant difference between the groups was found on any study day as well as in the mean change from baseline over all four days. We could not show transfer of iron-sucrose into maternal milk for the given dosage. Since parenteral iron sucrose is widely used in obstetrics, the results provide information about safety of parenteral iron sucrose in the lactation period. The findings are also in agreement with other reports on active biological mammary gland regulation of milk iron concentration.

Relation of dietary carbohydrates to lipid metabolism and the status of zinc and chromium in rabbits.

PubMed

Moersen, T J; Borgman, R F

1984-06-01

Rabbits were fed a purified ration known to produce alterations in lipid metabolism and cholelithiasis. During a 14-week period, group 1 was fed sucrose as the sole dietary carbohydrate, whereas group 2 was fed corn starch; the rations were equicaloric and the carbohydrate provided 43% of the calories. Serum cholesterol and triglyceride concentrations increased when the purified rations were fed, and these concentrations were often greater (toward the end of the trial) in rabbits fed the sucrose than in rabbits fed corn starch. Liver weight was increased by the sucrose feeding, but there were no differences as to concentrations of lipid, cholesterol, Cr, or Zn between treatments. The aortas of the sucrose group contained more lipid, and the cholesterol concentrations tended to be greater; but dietary carbohydrate had no effect on concentrations of Cr or Zn. A reduction in hair Cr concentration was noticed over time in the rabbits fed sucrose, but changes were not noticed in the Zn concentrations. Cholelithiasis tended to be more severe in rabbits fed sucrose.

Cloning and characterization of a Candida albicans maltase gene involved in sucrose utilization.

PubMed Central

Geber, A; Williamson, P R; Rex, J H; Sweeney, E C; Bennett, J E

1992-01-01

In order to isolate the structural gene involved in sucrose utilization, we screened a sucrose-induced Candida albicans cDNA library for clones expressing alpha-glucosidase activity. The C. albicans maltase structural gene (CAMAL2) was isolated. No other clones expressing alpha-glucosidase activity. were detected. A genomic CAMAL2 clone was obtained by screening a size-selected genomic library with the cDNA clone. DNA sequence analysis reveals that CAMAL2 encodes a 570-amino-acid protein which shares 50% identity with the maltase structural gene (MAL62) of Saccharomyces carlsbergensis. The substrate specificity of the recombinant protein purified from Escherichia coli identifies the enzyme as a maltase. Northern (RNA) analysis reveals that transcription of CAMAL2 is induced by maltose and sucrose and repressed by glucose. These results suggest that assimilation of sucrose in C. albicans relies on an inducible maltase enzyme. The family of genes controlling sucrose utilization in C. albicans shares similarities with the MAL gene family of Saccharomyces cerevisiae and provides a model system for studying gene regulation in this pathogenic yeast. Images PMID:1400249

Environmental enrichment attenuates cue-induced reinstatement of sucrose seeking in rats

PubMed Central

Grimm, Jeffery W.; Osincup, Daniel; Wells, Barbara; Manaois, Meghan; Fyall, Amber; Buse, Carl; Harkness, John H.

2010-01-01

This study examined the effect of environmental enrichment on sucrose seeking in rats made abstinent from sucrose for 1 month, as measured by response for a tone + light cue previously associated with 10% sucrose self-administration. Rats were either enriched throughout the study (experiment 1) or only after sucrose self-administration training (experiment 2). Enrichment consisted of either housing the rats in pairs or grouping four rats (ENR4) in a large environment, both with novel objects. Controls (CON) were singly housed without novel objects. In experiment 1, ENR4 rats responded less to the sucrose-paired cue versus CON rats, but this difference was not statistically significant. In contrast, the decrease in response of ENR4 rats versus CON rats in experiment 2 was dramatic and significant. These findings, along with findings from other laboratories, support a hypothesis that the enrichment may provide individuals with a greater ability to discriminate the availability of reward. This may impart a decreased vulnerability to relapse behavior. Therefore, these results are relevant to both eating disorder and drug addiction – disorders characterized by relapse. PMID:19020412

Ovarian Control of Nectar Collection in the Honey Bee (Apis mellifera)

PubMed Central

Siegel, Adam J.; Freedman, Colin; Page, Robert E.

2012-01-01

Honey bees are a model system for the study of division of labor. Worker bees demonstrate a foraging division of labor (DOL) by biasing collection towards carbohydrates (nectar) or protein (pollen). The Reproductive ground-plan hypothesis of Amdam et al. proposes that foraging DOL is regulated by the networks that controlled foraging behavior during the reproductive life cycle of honey bee ancestors. Here we test a proposed mechanism through which the ovary of the facultatively sterile worker impacts foraging bias. The proposed mechanism suggests that the ovary has a regulatory effect on sucrose sensitivity, and sucrose sensitivity impacts nectar loading. We tested this mechanism by measuring worker ovary size (ovariole number), sucrose sensitivity, and sucrose solution load size collected from a rate-controlled artificial feeder. We found a significant interaction between ovariole number and sucrose sensitivity on sucrose solution load size when using low concentration nectar. This supports our proposed mechanism. As nectar and pollen loading are not independent, a mechanism impacting nectar load size would also impact pollen load size. PMID:22558073

Use of glutaraldehyde and benzalkonium chloride for minimizing post-harvest physio-chemical and microbial changes responsible for sucrose losses in sugar cane.

PubMed

Singh, Pushpa; Arya, Namita; Tiwari, Priyanka; Suman, Archna; Rai, R K; Shrivastava, A K; Solomon, S

2008-08-27

Sugar cane is sensitive to enormous sucrose losses induced by physio-chemical and microbial changes, the severity being increased during the time lag between harvest and crushing in the mills. Minimization of the sucrose losses in the field is essential for better sugar recovery and prevention of sucrose losses. An experiment was conducted to evaluate the efficacy of glutaraldehyde and benzalkonium chloride for their effects on the microbial counts and physio-chemical changes responsible for sucrose losses. Glutaraldehyde and benzalkonium chloride (1000 + 250 ppm) reduced the losses in sucrose content to 7.1% as compared to the 30.8% loss in the control, thus improving the performance by 76.9%. The application of chemicals reduced the acid invertase activity (by 60%), lowered weight loss, titrable acidity, reducing sugars content, dextran, ethanol, and ethylene production and respiration rates. The application led to the reduction in the total bacterial, fungal, Leuconostoc, and yeast counts by 67.92, 51.3%, 26.08, and 51.2%, respectively.

Sucrose fed-batch strategy enhanced biomass, polysaccharide, and ganoderic acids production in fermentation of Ganoderma lucidum 5.26.

PubMed

Wei, Zhen-hua; Liu, Lianliang; Guo, Xiao-feng; Li, Yan-jun; Hou, Bao-chao; Fan, Qiu-ling; Wang, Kai-xiang; Luo, Yingdi; Zhong, Jian-jiang

2016-01-01

Ganoderma, as a Chinese traditional medicine, has multiple bioactivities. However, industrial production was limited due to low yield during Ganoderma fermentation. In this work, sucrose was found to greatly enhance intracellular polysaccharide (IPS) content and specific extracellular polysaccharide (EPS) production rate. The mechanism was studied by analyzing the activities of enzymes related to polysaccharide biosynthesis. The results revealed that sucrose regulated the activities of phosphoglucomutase and phosphoglucose isomerase. When glucose and sucrose mixture was used as carbon source, biomass, polysaccharide and ganoderic acids (GAs) production was greatly enhanced. A sucrose fed-batch strategy was developed in 10-L bioreactor, and was scaled up to 300-L bioreactor. The biomass, EPS and IPS production was 25.5, 2.9 and 4.8 g/L, respectively, which was the highest biomass and IPS production in pilot scale. This study provides information for further understanding the regulation mechanism of Ganoderma polysaccharide biosynthesis. It demonstrates that sucrose fed-batch is a useful strategy for enhancing Ganoderma biomass, polysaccharide and GAs production.

Electrical stimulation of the lateral habenula produces an inhibitory effect on sucrose self-administration.

PubMed

Friedman, Alexander; Lax, Elad; Dikshtein, Yahav; Abraham, Lital; Flaumenhaft, Yakov; Sudai, Einav; Ben-Tzion, Moshe; Yadid, Gal

2011-01-01

The lateral habenula (LHb) plays a role in prediction of negative reinforcement, punishment and aversive responses. In the current study, we examined the role that the LHb plays in regulation of negative reward responses and aversion. First, we tested the effect of intervention in LHb activity on sucrose reinforcing behavior. An electrode was implanted into the LHb and rats were trained to self-administer sucrose (20%; 16 days) until at least three days of stable performance were achieved (as represented by the number of active lever presses in self-administration cages). Rats subsequently received deep brain stimulation (DBS) of the LHb, which significantly reduced sucrose self-administration levels. In contrast, lesion of the LHb increased sucrose-seeking behavior, as demonstrated by a delayed extinction response to substitution of sucrose with water. Furthermore, in a modified non-rewarding conditioned-place-preference paradigm, DBS of the LHb led to aversion to the context associated with stimulation of this brain region. We postulate that electrical stimulation of the LHb attenuates positive reward-associated reinforcement by natural substances. Copyright © 2010 Elsevier Ltd. All rights reserved.

Diet and Dental Caries: The Pivotal Role of Free Sugars Reemphasized.

PubMed

Sheiham, A; James, W P T

2015-10-01

The importance of sugars as a cause of caries is underemphasized and not prominent in preventive strategies. This is despite overwhelming evidence of its unique role in causing a worldwide caries epidemic. Why this neglect? One reason is that researchers mistakenly consider caries to be a multifactorial disease; they also concentrate mainly on mitigating factors, particularly fluoride. However, this is to misunderstand that the only cause of caries is dietary sugars. These provide a substrate for cariogenic oral bacteria to flourish and to generate enamel-demineralizing acids. Modifying factors such as fluoride and dental hygiene would not be needed if we tackled the single cause--sugars. In this article, we demonstrate the sensitivity of cariogenesis to even very low sugars intakes. Quantitative analyses show a log-linear dose-response relationship between the sucrose or its monosaccharide intakes and the progressive lifelong development of caries. This results in a substantial dental health burden throughout life. Processed starches have cariogenic potential when accompanying sucrose, but human studies do not provide unequivocal data of their cariogenicity. The long-standing failure to identify the need for drastic national reductions in sugars intakes reflects scientific confusion partly induced by pressure from major industrial sugar interests. © International & American Associations for Dental Research 2015.

Scattering Response of Sucrose Clusters with Intense XFEL Pulses in Water Window

NASA Astrophysics Data System (ADS)

Ho, Phay; Benedikt Daurer, Benedikt; Bielecki, Johan; Hantke, Max; Maia, Filipe; Knight, Chris; Hajdu, Janos; Young, Linda; Bostedt, Christoph

2017-04-01

We present a combined experimental and theoretical study about the effects of non-linear x-ray ionization dynamics on the scattering response of molecular clusters in the soft x-ray regime that includes and goes beyond the water window. Nanosized sucrose clusters were irradiated with intense XFEL pulses (photon energy from 500 to 1500 eV and pulse duration of 180 fs). Surprisingly, the measured scattering signals near the oxygen K-edge in the water window are found to be substantially smaller than those at higher photon energies. We employ Monte-Carlo/Molecular Dynamics calculations to investigate the x-ray processes as a function of pulse parameters (photon energy, bandwidth and pulse duration) and cluster size. We demonstrate the important role of resonant excitation (RE) in the molecular scattering response in the water window. In particular, 1s ->2p RE cycling enabled in the oxygen atom/ion provide additional ionization pathways which, combined with the long pulse duration, lead to substantial reduction in scattering power of sugar clusters for photon energies just below the oxygen K-edge. Supported by the Chemical Sciences, Geosciences, and Biosciences Division, Office of Basic Energy Sciences, Office of Science, US Dept of Energy, Contract DE-AC02-06CH11357.

Supplemental fructose attenuates postprandial glycemia in Zucker fatty fa/fa rats.

PubMed

Wolf, Bryan W; Humphrey, Phillip M; Hadley, Craig W; Maharry, Kati S; Garleb, Keith A; Firkins, Jeffrey L

2002-06-01

Experiments were conducted to evaluate the effects of supplemental fructose on postprandial glycemia. After overnight food deprivation, Zucker fatty fa/fa rats were given a meal glucose tolerance test. Plasma glucose response was determined for 180 min postprandially. At a dose of 0.16 g/kg body, fructose reduced (P < 0.05) the incremental area under the curve (AUC) by 34% when supplemented to a glucose challenge and by 32% when supplemented to a maltodextrin (a rapidly digested starch) challenge. Similarly, sucrose reduced (P = 0.0575) the incremental AUC for plasma glucose when rats were challenged with maltodextrin. Second-meal glycemic response was not affected by fructose supplementation to the first meal, and fructose supplementation to the second meal reduced (P < 0.05) postprandial glycemia when fructose had been supplemented to the first meal. In a dose-response study (0.1, 0.2, and 0.5 g/kg body), supplemental fructose reduced (P < 0.01) the peak rise in plasma glucose (linear and quadratic effects). In the final experiment, a low dose of fructose (0.075 g/kg body) reduced (P < 0.05) the incremental AUC by 18%. These data support the hypothesis that small amounts of oral fructose or sucrose may be useful in lowering the postprandial blood glucose response.

Application of a newly developed and validated high-performance thin-layer chromatographic method to control honey adulteration.

PubMed

Puscas, Anitta; Hosu, Anamaria; Cimpoiu, Claudia

2013-01-11

Honey is a saturated solution of sugars, used for a long time as a natural source of sugars and is an important ingredient in traditional medicine due to its antimicrobial, anti-inflammatory and antioxidant effects. Therefore, methods for quality control of honey and detection of its adulteration are very important. For this reason, the aim of this study is to develop and validate a new, simple and economical analytical method for detecting the adulteration of some Romanian honeys based on high-performance thin-layer chromatography (HPTLC) combined with image analysis. The proposed method involved the chromatographic separations of glucose, fructose and sucrose on silica gel HPTLC plates, developed twice with ethyl acetate-pyridine-water-acetic acid, 6:3:1:0.5 (v/v/v/v), followed by dipping in an immersion solution. The documentation of plates was performed using TLC visualization device and the images of plates were processed using a digital processor. The developed HPTLC method was validated for selectivity, linearity and range, LOD and LOQ, precision, robustness and accuracy. The method was then applied for quantitative determination of glucose, fructose and sucrose from different types of Romanian honeys, commercially available. Copyright © 2012 Elsevier B.V. All rights reserved.

Investigation of a tubular dual-stator flux-switching permanent-magnet linear generator for free-piston energy converter

NASA Astrophysics Data System (ADS)

Sui, Yi; Zheng, Ping; Tong, Chengde; Yu, Bin; Zhu, Shaohong; Zhu, Jianguo

2015-05-01

This paper describes a tubular dual-stator flux-switching permanent-magnet (PM) linear generator for free-piston energy converter. The operating principle, topology, and design considerations of the machine are investigated. Combining the motion characteristic of free-piston Stirling engine, a tubular dual-stator PM linear generator is designed by finite element method. Some major structural parameters, such as the outer and inner radii of the mover, PM thickness, mover tooth width, tooth width of the outer and inner stators, etc., are optimized to improve the machine performances like thrust capability and power density. In comparison with conventional single-stator PM machines like moving-magnet linear machine and flux-switching linear machine, the proposed dual-stator flux-switching PM machine shows advantages in higher mass power density, higher volume power density, and lighter mover.

Primordial black holes in linear and non-linear regimes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Allahyari, Alireza; Abolhasani, Ali Akbar; Firouzjaee, Javad T., E-mail: allahyari@physics.sharif.edu, E-mail: j.taghizadeh.f@ipm.ir

We revisit the formation of primordial black holes (PBHs) in the radiation-dominated era for both linear and non-linear regimes, elaborating on the concept of an apparent horizon. Contrary to the expectation from vacuum models, we argue that in a cosmological setting a density fluctuation with a high density does not always collapse to a black hole. To this end, we first elaborate on the perturbation theory for spherically symmetric space times in the linear regime. Thereby, we introduce two gauges. This allows to introduce a well defined gauge-invariant quantity for the expansion of null geodesics. Using this quantity, we arguemore » that PBHs do not form in the linear regime irrespective of the density of the background. Finally, we consider the formation of PBHs in non-linear regimes, adopting the spherical collapse picture. In this picture, over-densities are modeled by closed FRW models in the radiation-dominated era. The difference of our approach is that we start by finding an exact solution for a closed radiation-dominated universe. This yields exact results for turn-around time and radius. It is important that we take the initial conditions from the linear perturbation theory. Additionally, instead of using uniform Hubble gauge condition, both density and velocity perturbations are admitted in this approach. Thereby, the matching condition will impose an important constraint on the initial velocity perturbations δ {sup h} {sub 0} = −δ{sub 0}/2. This can be extended to higher orders. Using this constraint, we find that the apparent horizon of a PBH forms when δ > 3 at turn-around time. The corrections also appear from the third order. Moreover, a PBH forms when its apparent horizon is outside the sound horizon at the re-entry time. Applying this condition, we infer that the threshold value of the density perturbations at horizon re-entry should be larger than δ {sub th} > 0.7.« less

Sugar-snap cookie dough setting: the impact of sucrose on gluten functionality.

PubMed

Pareyt, Bram; Brijs, Kristof; Delcour, Jan A

2009-09-09

In sugar-snap cookie making, sucrose influences the physicochemical transformations of the flour components and is responsible for both cookie sweetness and texture. Sucrose, together with low moisture levels, raises the starch gelatinization temperature to such an extent that little if any of it gelatinizes during baking. However, there is no agreement on the effects that it has on gluten during cookie making. The present study revealed that increasing sucrose levels in the recipe increasingly delay or inhibit gluten cross-linking, as judged from the loss of sodium dodecyl sulfate-extractable protein. This causes cookies containing higher sucrose levels to set later and to have a larger diameter. Gluten entanglement and/or cross-linking result in resistance to collapse, at the same time, cause setting during baking and, hence, determine cookie diameter.

Effect of diet quality and ambient temperature on the use of torpor by two species of neotropical nectar-feeding bats.

PubMed

Ayala-Berdon, Jorge; Vázquez-Fuerte, Rommy; Beamonte-Barrientos, René; Schondube, Jorge E

2017-03-01

Neotropical bats use torpor as a strategy to save energy when they experience a low energy intake and/or low ambient temperature ( T a ). Digestive physiology limits the energy intake of several glossophaginid bats, and could play an important role in the onset of torpor in these tropical animals. We measured the effect that diet quality and T a had on the use of torpor by the nectar-feeding bats Glossophaga soricina and Leptonycteris yerbabuenae Captive bats were fed with 5% (low) or 35% (high) sucrose solutions while exposed to two different T a (17.7 and 23.2°C; low T a and high T a ) in four different treatments: (1) high sucrose:high T a , (2) high sucrose:low T a , (3) low sucrose:high T a and (4) low sucrose:low T a We measured their energy intake, changes in body mass (Δ M b ) and skin temperature ( T skin ) as response variables. Energy intake (in 10 h) was limited when both species fed on 5% sucrose, but body mass gain was only affected in G. soricina. Energy intake and T a had a negative effect on the minimum T skin of both species, and Δ M b affected the time that G. soricina used torpor. Both species remained normothermic on the high sucrose:high T a treatment, but used torpor on the other three treatments. Bats used torpor during their resting and activity periods. Leptonycteris yerbabuenae spent more time in torpor in the low sucrose : high T a treatment, while G. soricina used this strategy for longer periods of time in the high sucrose : low T a treatment. We found that diet quality and T a played an important role in the use of torpor by nectar-feeding bats. © 2017. Published by The Company of Biologists Ltd.

Sucrose ingestion after exhaustive exercise accelerates liver, but not muscle glycogen repletion compared with glucose ingestion in trained athletes.

PubMed

Fuchs, Cas J; Gonzalez, Javier T; Beelen, Milou; Cermak, Naomi M; Smith, Fiona E; Thelwall, Pete E; Taylor, Roy; Trenell, Michael I; Stevenson, Emma J; van Loon, Luc J C

2016-06-01

The purpose of this study was to assess the effects of sucrose vs. glucose ingestion on postexercise liver and muscle glycogen repletion. Fifteen well-trained male cyclists completed two test days. Each test day started with glycogen-depleting exercise, followed by 5 h of recovery, during which subjects ingested 1.5 g·kg(-1)·h(-1) sucrose or glucose. Blood was sampled frequently and (13)C magnetic resonance spectroscopy and imaging were employed 0, 120, and 300 min postexercise to determine liver and muscle glycogen concentrations and liver volume. Results were as follows: Postexercise muscle glycogen concentrations increased significantly from 85 ± 27 (SD) vs. 86 ± 35 mmol/l to 140 ± 23 vs. 136 ± 26 mmol/l following sucrose and glucose ingestion, respectively (no differences between treatments: P = 0.673). Postexercise liver glycogen concentrations increased significantly from 183 ± 47 vs. 167 ± 65 mmol/l to 280 ± 72 vs. 234 ± 81 mmol/l following sucrose and glucose ingestion, respectively (time × treatment, P = 0.051). Liver volume increased significantly over the 300-min period after sucrose ingestion only (time × treatment, P = 0.001). As a result, total liver glycogen content increased during postexercise recovery to a greater extent in the sucrose treatment (from 53.6 ± 16.2 to 86.8 ± 29.0 g) compared with the glucose treatment (49.3 ± 25.5 to 65.7 ± 27.1 g; time × treatment, P < 0.001), equating to a 3.4 g/h (95% confidence interval: 1.6-5.1 g/h) greater repletion rate with sucrose vs. glucose ingestion. In conclusion, sucrose ingestion (1.5 g·kg(-1)·h(-1)) further accelerates postexercise liver, but not muscle glycogen repletion compared with glucose ingestion in trained athletes. Copyright © 2016 the American Physiological Society.

Anti-inflammatory effects of sucrose-derived oligosaccharides produced by a constitutive mutant L. mesenteroides B-512FMCM dextransucrase in high fat diet-fed mice.

PubMed

Kang, Min-Gyung; Lee, Hee Jae; Cho, Jae-Young; Kim, Kanghwa; Yang, Soo Jin; Kim, Doman

2016-08-26

Oligosaccharide (OS) is used as a sugar replacement as well as an ingredient in functional foods because of its beneficial effects, mainly on reducing calorie content and promoting intestinal health. By contrast, the effects of OS on inflammation are less well investigated. The purpose of this study was to investigate the effects of sucrose-derived OS on glucose control and inflammation in high fat (HF) diet-fed mice. Male C57BL6 mice were randomly assigned to six treatment groups (n = 10-14 mice per group): 1) lean control (CON), 2) HF control, 3) HF-low sucrose (LS, 100 mg/kg/day), 4) HF-high sucrose (HS, 1000 mg/kg/day), 5) HF-low OS (LOS, 100 mg/kg/day), and 6) HF-high OS (HOS, 1000 mg/kg/day). PBS (vehicle), sucrose, and OS were administered by stomach gavage. Body weight, food intake, and markers of liver function (activities of aspartate aminotransferase and alanine aminotransferase) were not affected by the treatments. HOS treatment decreased levels of serum glucose, insulin, and homeostasis model assessment-insulin resistance compared with sucrose treatment. However, serum adiponectin levels of the HOS group were higher than those of the sucrose groups. Serum levels of the pro-inflammatory cytokines interleukin-6 (IL-6) and fetuin-A were lower in the HOS group than in the sucrose groups. Hepatic gene expression levels of pro-inflammatory cytokines and related factors (fetuin-A, NF-κB, TLR4, TNF-alpha, and IL-6) were decreased and the levels of insulin signaling-related molecules (sirtuin 1, insulin receptor, and Akt) were increased in HOS-treated mice as compared with sucrose-treated mice. These results demonstrate that OS treatment is effective in improving glucose control and inflammation in high fat diet-fed mice. Copyright © 2016 Elsevier Inc. All rights reserved.

Dosakaya Juice Assuages Development of Sucrose Induced Impaired Glucose Tolerance and Imbalance in Antioxidant Defense

PubMed Central

Kumar, Dommati Anand; Sweeya, Pisupati S. R.; Shukla, Srishti; Anusha, Sanga Venkata; Akshara, Dasari; Madhusudana, Kuncha; Tiwari, Ashok Kumar

2015-01-01

Objective: The objective was to explore the effect of Dosakaya (DK) (Cucumis melo var. chito) juice on sucrose induced dysglycemia and disturbances in antioxidant defense in rats. Materials and Methods: Rats were preconditioned with DK juice before administration of sucrose beverage continuously for 1-month. Blood glucose tolerance test and glutathione (GSH) homeostasis pathways in kidney were analyzed in different group of animals at the end of the study. Results: DK juice diffused (P < 0.001) hypertriglyceridemia inducing effect of sucrose and arrested sucrose induced weight gain. It improved glucose tolerance ability by significantly reducing (P < 0.05) first-hour glycemic excursion and decreasing 2 h glycemic load (P < 0.05) following oral glucose tolerance test in sucrose fed animals. Furthermore, disturbances in antioxidant defense mechanisms in terms of GSH homeostasis in kidney were restored due to juice feeding. DK juice administration checked reduction in GSH-S-transferase and glyoxalase-I activity, thus, significantly mitigated lipid peroxidation (P < 0.05), and formation of advanced glycation end-products (P < 0.001) in kidney and serum (P < 0.01). Quantitative analysis of juice found it a rich source of protein and polyphenols. Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) analysis revealed the presence of multiple protein bands in whole fruit juice. Therefore, SDS-PAGE protein fingerprint of DK juice may serve as a quality control tool for standardization of juice. Conclusion: The whole fruit juice of DK may become cost-effective, affordable health beverage in extenuating ill-health effects of sugar consumption. This is the first report identifying DK juice in preventing development dysglycemia, dyslipidemia, and oxidative stress induced due to chronic sucrose feeding in rats. SUMMARY Chronic sucrose consumption induced development of dysglycemia and also impaired antioxidant defense mechanism in rats. The oral administration of Dosakaya juice prior to sucrose feeding however, mitigated the development of dysglycemia and impairment in antioxidant defense in rats. PMID:26929582

Separation of Bacteria, Protozoa and Carbon Nanotubes by Density Gradient Centrifugation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mortimer, Monika; Petersen, Elijah; Buchholz, Bruce

Sustainable production and use of carbon nanotube (CNT)-enabled materials require efficient assessment of CNT environmental hazards, including the potential for CNT bioaccumulation and biomagnification in environmental receptors. Microbes, as abundant organisms responsible for nutrient cycling in soil and water, are important ecological receptors for studying the effects of CNTs. Quantification of CNT association with microbial cells requires efficient separation of CNT-associated cells from individually dispersed CNTs and CNT agglomerates. Here in this paper, we designed, optimized, and demonstrated procedures for separating bacteria (Pseudomonas aeruginosa) from unbound multiwall carbon nanotubes (MWCNTs) and MWCNT agglomerates using sucrose density gradient centrifugation. We demonstratemore » separation of protozoa (Tetrahymena thermophila) from MWCNTs, bacterial agglomerates, and protozoan fecal pellets by centrifugation in an iodixanol solution. The presence of MWCNTs in the density gradients after centrifugation was determined by quantification of 14C-labeled MWCNTs; the recovery of microbes from the density gradient media was confirmed by optical microscopy. Protozoan intracellular contents of MWCNTs and of bacteria were also unaffected by the designed separation process. Lastly, the optimized methods contribute to improved efficiency and accuracy in quantifying MWCNT association with bacteria and MWCNT accumulation in protozoan cells, thus supporting improved assessment of CNT bioaccumulation.« less

Separation of Bacteria, Protozoa and Carbon Nanotubes by Density Gradient Centrifugation

DOE PAGES

Mortimer, Monika; Petersen, Elijah; Buchholz, Bruce; ...

2016-10-12

Sustainable production and use of carbon nanotube (CNT)-enabled materials require efficient assessment of CNT environmental hazards, including the potential for CNT bioaccumulation and biomagnification in environmental receptors. Microbes, as abundant organisms responsible for nutrient cycling in soil and water, are important ecological receptors for studying the effects of CNTs. Quantification of CNT association with microbial cells requires efficient separation of CNT-associated cells from individually dispersed CNTs and CNT agglomerates. Here in this paper, we designed, optimized, and demonstrated procedures for separating bacteria (Pseudomonas aeruginosa) from unbound multiwall carbon nanotubes (MWCNTs) and MWCNT agglomerates using sucrose density gradient centrifugation. We demonstratemore » separation of protozoa (Tetrahymena thermophila) from MWCNTs, bacterial agglomerates, and protozoan fecal pellets by centrifugation in an iodixanol solution. The presence of MWCNTs in the density gradients after centrifugation was determined by quantification of 14C-labeled MWCNTs; the recovery of microbes from the density gradient media was confirmed by optical microscopy. Protozoan intracellular contents of MWCNTs and of bacteria were also unaffected by the designed separation process. Lastly, the optimized methods contribute to improved efficiency and accuracy in quantifying MWCNT association with bacteria and MWCNT accumulation in protozoan cells, thus supporting improved assessment of CNT bioaccumulation.« less

Separation of Bacteria, Protozoa and Carbon Nanotubes by Density Gradient Centrifugation

PubMed Central

Mortimer, Monika; Petersen, Elijah J.; Buchholz, Bruce A.; Holden, Patricia A.

2016-01-01

Sustainable production and use of carbon nanotube (CNT)-enabled materials require efficient assessment of CNT environmental hazards, including the potential for CNT bioaccumulation and biomagnification in environmental receptors. Microbes, as abundant organisms responsible for nutrient cycling in soil and water, are important ecological receptors for studying the effects of CNTs. Quantification of CNT association with microbial cells requires efficient separation of CNT-associated cells from individually dispersed CNTs and CNT agglomerates. Here, we designed, optimized, and demonstrated procedures for separating bacteria (Pseudomonas aeruginosa) from unbound multiwall carbon nanotubes (MWCNTs) and MWCNT agglomerates using sucrose density gradient centrifugation. We demonstrate separation of protozoa (Tetrahymena thermophila) from MWCNTs, bacterial agglomerates, and protozoan fecal pellets by centrifugation in an iodixanol solution. The presence of MWCNTs in the density gradients after centrifugation was determined by quantification of 14C-labeled MWCNTs; the recovery of microbes from the density gradient media was confirmed by optical microscopy. Protozoan intracellular contents of MWCNTs and of bacteria were also unaffected by the designed separation process. The optimized methods contribute to improved efficiency and accuracy in quantifying MWCNT association with bacteria and MWCNT accumulation in protozoan cells, thus supporting improved assessment of CNT bioaccumulation. PMID:27917301

Effects of radiochemical impurities on measurements of transfer constants for [14C]sucrose permeation of normal and injured blood-brain barrier of rats.

PubMed

Preston, E; Foster, D O; Mills, P A

1998-01-01

Radiolabeled sucrose is often used to assess blood-brain barrier (BBB) injury in the rat, but published transfer constants (K[i]s) for sucrose permeation of the intact BBB (control K[i]s) are highly discrepant. A potential problem with the commonly used tracer, [14C(U)]sucrose, is radiolytic generation, preuse, of radiocontaminants that might readily penetrate the BBB. How such contaminants might affect measurements of sucrose K(i)s was examined for both the intact and the ischemically injured BBB. Three stocks of [14C(U)]sucrose were studied: newly purchased ("new"), 4-year-old, and 7-year-old. A high purity (99.9%) "new" and a 2-year-old stock of [3H(fructose-1)]sucrose were also tested. Pentobarbital-anesthetized male Sprague-Dawley rats were injected i.v. with each tracer separately (six to eight rats) and K(i)s in five brain regions were measured by the multiple-time graphical method. The "new" 14C-, "new" 3H-, and 2-year-old 3H-sucrose yielded comparable K(i)s , ranging from 1.2 +/- 0.1 to 2.4 +/- 0.3 nl x g(-1) x s(-1) (mean +/- SE) across the regions. The two old stocks of 14C-sucrose yielded significantly higher regional K(i)s : 5.1-6.3 (4-year-old) and 8.4-9.7 (7-year-old). Thin-layer chromatography of the three 14C-tracers revealed that each contained radioimpurities (ca. 2% in both the "new" and 4-year-old, and 9% in the 7-year-old), but that the old stocks contained larger amounts of relatively mobile (more lipophilic) impurities, which can be suspected as the main cause of the elevated K(i)s obtained. Additional rats were subjected to 10 min of cerebral ischemia, which effects a delayed BBB injury, and 6 h later the "new" 3H- and the 4-year-old 14C-sucrose were injected together. The K(i)s for both tracers were elevated by like, absolute amounts (deltaK[i]s), but by very different percentages, over their disparate baseline values in uninjured rats (for striatum and hippocampus, the most injured regions, deltaK(i)s were 3.9 to 4.4 nl x g[-1] x s[-1]). It is concluded that radiolysis of [14C(U)]sucrose yields certain labeled products that readily cross the BBB and that can seriously distort baseline K(i)s , even if present only in very small amounts. While this appears not to compromise assessment of BBB injury, definition of the authentic range of baseline, sucrose K(i)s for the rat BBB would appear to remain a challenge.

Activation of muscarinic receptors in rat parotid acinar cells induces AQP5 trafficking to nuclei and apical plasma membrane.

PubMed

Cho, Gota; Bragiel, Aneta M; Wang, Di; Pieczonka, Tomasz D; Skowronski, Mariusz T; Shono, Masayuki; Nielsen, Søren; Ishikawa, Yasuko

2015-04-01

The subcellular distribution of aquaporin-5 (AQP5) in rat parotid acinar cells in response to muscarinic acetylcholine receptor (mAChR) activation remains unclear. Immunoconfocal and immunoelectron microscopy were used to visualize the distribution of AQP5 in parotid acinar cells. Western blotting was used to analyze AQP5 levels in membranes. To clarify the characteristics of membrane domains associated with AQP5, detergent solubility and sucrose-density flotation experiments were performed. Under control conditions, AQP5 was diffusely distributed on the apical plasma membrane (APM) and apical plasmalemmal region and throughout the cytoplasm. Upon mAChR activation, AQP5 was predominantly located in the nucleus, APM and lateral plasma membrane (LPM). Subsequently, localization of AQP5 in the nucleus, APM and LPM was decreased. Prolonged atropine treatment inhibited mAChR agonist-induced translocation of AQP5 to the nucleus, APM and LPM. AQP5 levels were enhanced in isolated nuclei and nuclear membranes prepared from parotid tissues incubated with mAChR agonist. mAChR agonist induced AQP5 levels in both soluble and insoluble nuclear fractions solubilized with Triton X-100 or Lubrol WX. Small amounts of AQP5 in nuclei were detected using low-density sucrose gradient. When AQP5 was present in the nuclear membrane, nuclear size decreased. The activation of mAChR induced AQP5 translocation to the nucleus, APM and LPM, and AQP5 may trigger water transport across the nuclear membrane and plasma membrane in rat parotid acinar cells. AQP5 translocates to the nuclear membrane and may trigger the movement of water, inducing shrinkage of the nucleus and the start of nuclear functions. Copyright © 2015 Elsevier B.V. All rights reserved.

Natural honey and cardiovascular risk factors; effects on blood glucose, cholesterol, triacylglycerole, CRP, and body weight compared with sucrose.

PubMed

Yaghoobi, N; Al-Waili, Noori; Ghayour-Mobarhan, M; Parizadeh, S M R; Abasalti, Z; Yaghoobi, Z; Yaghoobi, F; Esmaeili, H; Kazemi-Bajestani, S M R; Aghasizadeh, R; Saloom, Khelod Y; Ferns, G A A

2008-04-20

It has been found that honey ameliorates cardiovascular risk factors in healthy individuals and in patients with elevated risk factors. The present study investigated the effect of natural honey on total cholesterol, low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), triacylglycerole, C-reactive protein (CRP), fasting blood glucose (FBG), and body weight in overweight individuals. There were 55 patients, overweight or obese, who were randomly recruited into the study and assigned into two groups: control group (17 subjects) and experimental group (38 subjects). Patients in the control group received 70 g of sucrose daily for a maximum of 30 days and patients in the experimental group received 70 g of natural honey for the same period. In the control and experimental groups, body weight, body mass index, body fat weight, total cholesterol, LDL-C, HDL-C, triacylglycerole, FBG, and CRP were measured before treatment and at day 31 after the commencement of treatment. Results showed that honey caused a mild reduction in body weight (1.3%) and body fat (1.1%). Honey reduced total cholesterol (3%), LDL-C (5.8), triacylglycerole (11%), FBG (4.2%), and CRP (3.2%), and increased HDL-C (3.3%) in subjects with normal values, while in patients with elevated variables, honey caused reduction in total cholesterol by 3.3%, LDL-C by 4.3%, triacylglycerole by 19%, and CRP by 3.3% (p < 0.05). It is our conclusion that consumption of natural honey reduces cardiovascular risk factors, particularly in subjects with elevated risk factors, and it does not increase body weight in overweight or obese subjects.

Surface-Active Agents for Isolation of the Core Component of Avian Myeloblastosis Virus 1

PubMed Central

Stromberg, Kurt

1972-01-01

Sixty-one surface-active agents were evaluated in a procedure designed to assess their ability to remove the envelope from the core component of avian myeloblastosis virus (AMV). The procedure consisted of centrifugation of intact AMV through a series of sucrose gradients each containing an upper layer of agent at one of eight concentrations between 0.01 and 10%. The effectiveness of an agent in producing AMV cores was indicated by (i) the appearance of light-scattering bands in the region of core buoyant density in gradient tubes; (ii) the range of surfactant concentration over which these bands appeared; and (iii) an electron microscopy assessment by the negative-staining technique of the relative proportion of core to non-core material in each of these bands. Six nonionic surfactants were selected by this screening method for comparison in regard to recovery of core protein and endogenous ribonucleic acid (RNA)-dependent deoxyribonucleic acid (DNA) polymerase activity, as well as further morphologic evaluation by electron microscopy. The nonionic surfactants of the polyoxyethylene alcohol class (particularly, Sterox SL) were most effective. Nonionic surfactants of the polyoxyethylene alkylphenol class (particularly, Nonidet P-40) were also effective. Sterox SL and Nonidet P-40 each gave a more than fivefold increase in specific activity of endogenous RNA-dependent DNA polymerase, and each gave a low recovery of core protein. Sterox SL did not interfere to the extent that Nonidet P-40 did in procedures which involved spectrophotometric assay at 260 nm. The use of Sterox SL resulted in the least envelope contamination of core preparations by electron microscopy examination, the most recovery of protein and endogenous RNA-dependent DNA polymerase activity, and a core buoyant density in sucrose of 1.27 g/ml. Images PMID:4112071

Improvement of l-lactic acid productivity from sweet sorghum juice by repeated batch fermentation coupled with membrane separation.

PubMed

Wang, Yong; Meng, Hongyu; Cai, Di; Wang, Bin; Qin, Peiyong; Wang, Zheng; Tan, Tianwei

2016-07-01

In order to efficiently produce l-lactic acid from non-food feedstocks, sweet sorghum juice (SSJ), which is rich of fermentable sugars, was directly used for l-lactic acid fermentation by Lactobacillus rhamnosus LA-04-1. A membrane integrated repeated batch fermentation (MIRB) was developed for productivity improvement. High-cell-density fermentation was achieved with a final cell density (OD620) of 42.3, and the CCR effect was overcomed. When SSJ (6.77gL(-1) glucose, 4.51gL(-1) fructose and 50.46gL(-1) sucrose) was used as carbon source in MIRB process, l-lactic acid productivity was increased significantly from 1.45gL(-1)h(-1) (batch 1) to 17.55gL(-1)h(-1) (batch 6). This process introduces an effective way to produce l-lactic acid from SSJ. Copyright © 2016 Elsevier Ltd. All rights reserved.

Western blot (immunoblot) assay of small, round-structured virus associated with an acute gastroenteritis outbreak in Tokyo.

PubMed

Hayashi, Y; Ando, T; Utagawa, E; Sekine, S; Okada, S; Yabuuchi, K; Miki, T; Ohashi, M

1989-08-01

Small, round-structured virus (SRSV) was detected in a stool specimen of a patient during an acute gastroenteritis outbreak in Tokyo and was tentatively named SRSV-9. SRSV-9 was purified by sucrose velocity gradient centrifugation after CsCl density gradient centrifugation. The buoyant density of SRSV-9 appeared to be 1.36 g/ml in CsCl. A Western blot (immunoblot) assay using the biotin-avidin system revealed that SRSV-9 was antigenically related to the Hawaii agent but distinct from the Norwalk agent and contained a single major structural protein with a molecular size of 63.0 +/- 0.6 kilodaltons. The prevalence of SRSV-9 infection in Tokyo was surveyed by the Western blot antibody assay by using a crude virus preparation as the antigen. Seroconversion was observed in 56.5% of the patients involved in the outbreaks from which SRSV was detected by electron microscopy.

Effect of irradiance, sucrose, and CO2 concentration on the growth of potato (Solanum tuberosum L.) in vitro

NASA Technical Reports Server (NTRS)

Yorio, Neil C.; Wheeler, Raymond M.; Weigel, Russell C.

1995-01-01

Growth measurements were taken of potato plantlets (Solanum tuberosum L.) cvs. Norland (NL), Denali (DN), and Kennebec (KN), grown in vitro. Studies were conducted in a growth chamber, with nodal explants grown for 21 days on Murashige and Skoog salts with either 0, 1, 2, or 3% sucrose and capped with loose-fitted Magenta 2-way caps that allowed approximately 2.25 air exchanges/hour. Plantlets were exposed to either 100 or 300 micro mol/sq m/s photosynthetic photon flux (PPF), and the growth chamber was maintained at either 400 or 4000 micro mol/mol CO2. Regardless of PPF, all cvs. that were grown at 4000 micro mol/mol CO2 showed significant increases in total plantlet dry weight (TDW) and shoot length (SL) when sucrose was omitted from the media, indicating an autotrophic response. At 400 micro mol/mol CO2, all cvs. showed an increase in TDW and SL with increasing sucrose under both PPF levels. Within any sucrose treatment, the highest TDW for all cvs. resulted from 300 micro mol/sq m/s PPF and 4000 micro mol/mol CO2 At 4000 micro mol/mol CO2, TDW showed no further increase with sucrose levels above 1% for cvs. NL and DN at both PPF levels, suggesting that sucrose levels greater than 1% may hinder growth when CO2 enrichment is used.

A membrane-associated form of sucrose synthase and its potential role in synthesis of cellulose and callose in plants.

PubMed Central

Amor, Y; Haigler, C H; Johnson, S; Wainscott, M; Delmer, D P

1995-01-01

Sucrose synthase (SuSy; EC 2.4.1.13; sucrose + UDP reversible UDPglucose + fructose) has always been studied as a cytoplasmic enzyme in plant cells where it serves to degrade sucrose and provide carbon for respiration and synthesis of cell wall polysaccharides and starch. We report here that at least half of the total SuSy of developing cotton fibers (Gossypium hirsutum) is tightly associated with the plasma membrane. Therefore, this form of SuSy might serve to channel carbon directly from sucrose to cellulose and/or callose synthases in the plasma membrane. By using detached and permeabilized cotton fibers, we show that carbon from sucrose can be converted at high rates to both cellulose and callose. Synthesis of cellulose or callose is favored by addition of EGTA or calcium and cellobiose, respectively. These findings contrast with the traditional observation that when UDPglucose is used as substrate in vitro, callose is the major product synthesized. Immunolocalization studies show that SuSy can be localized at the fiber surface in patterns consistent with the deposition of cellulose or callose. Thus, these results support a model in which SuSy exists in a complex with the beta-glucan synthases and serves to channel carbon from sucrose to glucan. Images Fig. 1 Fig. 3 Fig. 4 PMID:7568131

A nicotinic acetylcholine receptor agonist affects honey bee sucrose responsiveness and decreases waggle dancing.

PubMed

Eiri, Daren M; Nieh, James C

2012-06-15

A nicotinic acetylcholine receptor agonist, imidacloprid, impairs memory formation in honey bees and has general effects on foraging. However, little is known about how this agonist affects two specific aspects of foraging: sucrose responsiveness (SR) and waggle dancing (which recruits nestmates). Using lab and field experiments, we tested the effect of sublethal doses of imidacloprid on (1) bee SR with the proboscis extension response assay, and (2) free-flying foragers visiting and dancing for a sucrose feeder. Bees that ingested imidacloprid (0.21 or 2.16 ng bee(-1)) had higher sucrose response thresholds 1 h after treatment. Foragers that ingested imidacloprid also produced significantly fewer waggle dance circuits (10.5- and 4.5-fold fewer for 50% and 30% sucrose solutions, respectively) 24 h after treatment as compared with controls. However, there was no significant effect of imidacloprid on the sucrose concentrations that foragers collected at a feeder 24 h after treatment. Thus, imidacloprid temporarily increased the minimum sucrose concentration that foragers would accept (short time scale, 1 h after treatment) and reduced waggle dancing (longer time scale, 24 h after treatment). The effect of time suggests different neurological effects of imidacloprid resulting from the parent compound and its metabolites. Waggle dancing can significantly increase colony food intake, and thus a sublethal dose (0.21 ng bee(-1), 24 p.p.b.) of this commonly used pesticide may impair colony fitness.

Sucrose-induced anthocyanin accumulation in vegetative tissue of Petunia plants requires anthocyanin regulatory transcription factors.

PubMed

Ai, Trinh Ngoc; Naing, Aung Htay; Arun, Muthukrishnan; Lim, Sun-Hyung; Kim, Chang Kil

2016-11-01

The effects of three different sucrose concentrations on plant growth and anthocyanin accumulation were examined in non-transgenic (NT) and transgenic (T 2 ) specimens of the Petunia hybrida cultivar 'Mirage rose' that carried the anthocyanin regulatory transcription factors B-Peru+mPAP1 or RsMYB1. Anthocyanin accumulation was not observed in NT plants in any treatments, whereas a range of anthocyanin accumulation was observed in transgenic plants. The anthocyanin content detected in transgenic plants expressing the anthocyanin regulatory transcription factors (B-Peru+mPAP1 or RsMYB1) was higher than that in NT plants. In addition, increasing sucrose concentration strongly enhanced anthocyanin content as shown by quantitative real-time polymerase chain reaction (qRT-PCR) analysis, wherein increased concentrations of sucrose enhanced transcript levels of the transcription factors that are responsible for the induction of biosynthetic genes involved in anthocyanin synthesis; this pattern was not observed in NT plants. In addition, sucrose affected plant growth, although the effects were different between NT and transgenic plants. Taken together, the application of sucrose could enhance anthocyanin production in vegetative tissue of transgenic Petunia carrying anthocyanin regulatory transcription factors, and this study provides insights about interactive effects of sucrose and transcription factors in anthocyanin biosynthesis in the transgenic plant. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Effect of seasonality and Cr(VI) on starch-sucrose partitioning and related enzymes in floating leaves of Salvinia minima.

PubMed

Rosa, Mariana; Prado, Carolina; Chocobar-Ponce, Silvana; Pagano, Eduardo; Prado, Fernando

2017-09-01

Effects of seasonality and increasing Cr(VI) concentrations on leaf starch-sucrose partitioning, sucrose- and starch-related enzyme activities, and carbon allocation toward leaf development were analyzed in fronds (floating leaves) of the floating fern Salvinia minima. Carbohydrates and enzyme activities of Cr-exposed fronds showed different patterns in winter and summer. Total soluble sugars, starch, glucose and fructose increased in winter fronds, while sucrose was higher in summer ones. Starch and soluble carbohydrates, except glucose, increased under increasing Cr(VI) concentrations in winter fronds, while in summer ones only sucrose increased under Cr(VI) treatment. In summer fronds starch, total soluble sugars, fructose and glucose practically stayed without changes in all assayed Cr(VI) concentrations. Enzyme activities related to starch and sucrose metabolisms (e.g. ADPGase, SPS, SS and AI) were higher in winter fronds than in summer ones. Total amylase and cFBPase activities were higher in summer fronds. Cr(VI) treatment increased enzyme activities, except ADPGase, in both winter and summer fronds but no clear pattern changes were observed. Data of this study show clearly that carbohydrate metabolism is differently perturbed by both seasonality and Cr(VI) treatment in summer and winter fronds, which affects leaf starch-sucrose partitioning and specific leaf area (SLA) in terms of carbon investment. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Synthesis and spectroscopic investigations of hydroxyapatite using a green chelating agent as template

NASA Astrophysics Data System (ADS)

Gopi, D.; Bhuvaneshwari, N.; Indira, J.; Kavitha, L.

2013-03-01

Hydroxyapatite [Ca10(PO4)6(OH)2, HAP] particles have been successfully synthesized by a cost-effective, eco-friendly green template method using natural and commercially available sucrose as a chelating agent. The sucrose used in this method has been extracted from various sources, three from natural and one from commercially available sources are exploited in our study to achieve a controlled crystallinity, particle size as well as uniform morphology. Spectral characterizations involving Fourier transform infrared spectroscopy (FT-IR) for the functional group analysis of sucrose and HAP; carbon-13 nuclear magnetic resonance spectroscopy (13C NMR) for the identification of the carbon atoms in sucrose and in HAP; liquid chromatography/mass spectrometry (LC-MS) for the determination of the hydrolyzed products of sucrose; and X-ray diffraction (XRD) techniques for the phase identification of the HAP particles were performed. The morphology of the HAP particles were assessed thoroughly using a scanning electron microscope (SEM) equipped with energy dispersive X-ray analysis (EDAX). The experimental results indicate that the obtained HAP using the natural sucrose as a chelating agent is of phase pure, with a well defined morphology having discrete particles without any agglomeration than the HAP from commercially available sucrose. Further, the reduced particle size can be achieved from the stem sugarcane extract as the source of the chelating agent.

Synthesis and spectroscopic investigations of hydroxyapatite using a green chelating agent as template.

PubMed

Gopi, D; Bhuvaneshwari, N; Indira, J; Kavitha, L

2013-03-01

Hydroxyapatite [Ca(10)(PO(4))(6)(OH)(2), HAP] particles have been successfully synthesized by a cost-effective, eco-friendly green template method using natural and commercially available sucrose as a chelating agent. The sucrose used in this method has been extracted from various sources, three from natural and one from commercially available sources are exploited in our study to achieve a controlled crystallinity, particle size as well as uniform morphology. Spectral characterizations involving Fourier transform infrared spectroscopy (FT-IR) for the functional group analysis of sucrose and HAP; carbon-13 nuclear magnetic resonance spectroscopy ((13)C NMR) for the identification of the carbon atoms in sucrose and in HAP; liquid chromatography/mass spectrometry (LC-MS) for the determination of the hydrolyzed products of sucrose; and X-ray diffraction (XRD) techniques for the phase identification of the HAP particles were performed. The morphology of the HAP particles were assessed thoroughly using a scanning electron microscope (SEM) equipped with energy dispersive X-ray analysis (EDAX). The experimental results indicate that the obtained HAP using the natural sucrose as a chelating agent is of phase pure, with a well defined morphology having discrete particles without any agglomeration than the HAP from commercially available sucrose. Further, the reduced particle size can be achieved from the stem sugarcane extract as the source of the chelating agent. Copyright © 2012 Elsevier B.V. All rights reserved.

Effects of Soil Salinity on Sucrose Metabolism in Cotton Leaves

PubMed Central

Zhang, Lei; Luo, Junyu; Dong, Helin; Ma, Yan; Zhao, Xinhua; Chen, Binglin; Sui, Ning; Zhou, Zhiguo; Meng, Yali

2016-01-01

This study investigated sucrose metabolism of the youngest fully expanded main-stem leaf (MSL) and the subtending leaf of cotton (Gossypium hirsutum L.) boll (LSCB) of salt-tolerant (CCRI-79) and salt-sensitive (Simian 3) cultivars and its relationship to boll weight under low, medium and high soil salinity stress in Dafeng, China, in 2013 and 2014. The results showed that with increased soil salinity, 1) both the chlorophyll content and net photosynthetic rate (Pn) decreased, while the internal CO2 concentration firstly declined, and then increased in the MSL and LSCB; 2) carbohydrate contents in the MSL reduced significantly, while sucrose and starch contents in the LSCB increased, as did the activities of sucrose phosphate synthase (SPS) and sucrose synthase (SuSy) in both the MSL and LSCB; 3) but invertase activity in both the MSL and LSCB did not change significantly. Our study also showed that the LSCB was more sensitive to soil salinity than was the MSL. Of the measured physiological indices, higher SPS activity, mainly controlled by sps3, may contribute to adaption of the LSCB to soil salinity stress because SPS is beneficial for efficiently sucrose synthesis, reduction of cellular osmotic potential and combined actions of Pn, and sucrose transformation rate and SPS may contribute to the reduction in boll weight under soil salinity stress. PMID:27228029

Pontine and Thalamic Influences on Fluid Rewards: III. Anticipatory Contrast for Sucrose and Corn Oil

PubMed Central

Liang, Nu-Chu; Norgren, Ralph; Grigson, Patricia S

2011-01-01

An anticipatory contrast effect (ACE) occurs when, across daily trials, an animal comes to respond less than normally to a first stimulus when it is followed shortly by a second, more preferred solution. Classically, ACE is studied using a low (L) concentration of saccharin or sucrose, followed by access to a higher (H) concentration of sucrose. Subjects in the control condition have two bouts of access to the weaker solution presented on the same schedule. The ACE is measured by the difference in intake of the first bout low solution between subjects in the low-low (L-L) vs. the low-high (L-H) conditions. Here we used this paradigm with sham feeding rats and determined that nutritional feedback was unnecessary for the development of ACE with two concentrations of sucrose or with two concentrations of corn oil. Next we showed that ibotenic acid lesions centered in the orosensory thalamus spared ACEs for both sucrose and corn oil. In contrast, lesions of the pontine parabrachial nuclei (PBN), the second central relay for taste in the rat, disrupted ACEs for both sucrose and corn oil. Although the sensory modalities needed for the oral detection of fats remain controversial, it appears that the PBN is involved in processing the comparison of disparate concentrations of sucrose and oil reward. PMID:21703289

Membrane Potentials of the Lobster Giant Axon Obtained by Use of the Sucrose-Gap Technique

PubMed Central

Julian, Fred J.; Moore, John W.; Goldman, David E.

1962-01-01

A method similar to the sucrose-gap technique introduced be Stäpfli is described for measuring membrane potential and current in singly lobster giant axons (diameter about 100 micra). The isotonic sucrose solution used to perfuse the gaps raises the external leakage resistance so that the recorded potential is only about 5 per cent less than the actual membrane potential. However, the resting potential of an axon in the sucrose-gap arrangement is increased 20 to 60 mv over that recorded by a conventional micropipette electrode when the entire axon is bathed in sea water. A complete explanation for this effect has not been discovered. The relation between resting potential and external potassium and sodium ion concentrations shows that potassium carries most of the current in a depolarized axon in the sucrose-gap arrangement, but that near the resting potential other ions make significant contributions. Lowering the external chloride concentration decreases the resting potential. Varying the concentration of the sucrose solution has little effect. A study of the impedance changes associated with the action potential shows that the membrane resistance decreases to a minimum at the peak of the spike and returns to near its initial value before repolarization is complete (a normal lobster giant axon action potential does not have an undershoot). Action potentials recorded simultaneously by the sucrose-gap technique and by micropipette electrodes are practically superposable. PMID:14452759

Intake of Ethanol, Sodium Chloride, Sucrose, Citric Acid, and Quinine Hydrochloride Solutions by Mice: A Genetic Analysis

PubMed Central

Bachmanov, A. A.; Reed, D. R.; Tordoff, M. G.; Price, R. A.; Beauchamp, G. K.

2013-01-01

Mice of the 129/J (129) and C57BL/6ByJ (B6) strains and their reciprocal F1 and F2 hybrids were offered solutions of ethanol, sucrose, citric acid, quinine hydrochloride, and NaCI in two-bottle choice tests. Consistent with earlier work, the B6 mice drank more ethanol, sucrose, citric acid, and quinine hydrochloride solution and less NaCI solution than did 129 mice. Analyses of each generation’s means and distributions showed that intakes of ethanol, quinine, sucrose, and NaCI were influenced by a few genes. The mode of inheritance was additive in the case of ethanol and quinine, for sucrose the genotype of the 129 strain was recessive, and for NaCI it was dominant. Citric acid intake appeared to be influenced by many genes with small effects, with the 129 genotype dominant. Correlations of sucrose consumption with ethanol and citric acid consumption were found among mice of the F2 generation, and the genetically determined component of these correlations was stronger than the component related to environmental factors. The genetically determined correlation between sucrose and ethanol intakes is consistent with the hypothesis that the higher ethanol intake by B6 mice depends, in part, on higher hedonic attractiveness of its sweet taste component. PMID:8990535

Stabilization of electron-scale turbulence by electron density gradient in national spherical torus experiment

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ruiz Ruiz, J.; White, A. E.; Ren, Y.

2015-12-15

Theory and experiments have shown that electron temperature gradient (ETG) turbulence on the electron gyro-scale, k{sub ⊥}ρ{sub e} ≲ 1, can be responsible for anomalous electron thermal transport in NSTX. Electron scale (high-k) turbulence is diagnosed in NSTX with a high-k microwave scattering system [D. R. Smith et al., Rev. Sci. Instrum. 79, 123501 (2008)]. Here we report on stabilization effects of the electron density gradient on electron-scale density fluctuations in a set of neutral beam injection heated H-mode plasmas. We found that the absence of high-k density fluctuations from measurements is correlated with large equilibrium density gradient, which ismore » shown to be consistent with linear stabilization of ETG modes due to the density gradient using the analytical ETG linear threshold in F. Jenko et al. [Phys. Plasmas 8, 4096 (2001)] and linear gyrokinetic simulations with GS2 [M. Kotschenreuther et al., Comput. Phys. Commun. 88, 128 (1995)]. We also found that the observed power of electron-scale turbulence (when it exists) is anti-correlated with the equilibrium density gradient, suggesting density gradient as a nonlinear stabilizing mechanism. Higher density gradients give rise to lower values of the plasma frame frequency, calculated based on the Doppler shift of the measured density fluctuations. Linear gyrokinetic simulations show that higher values of the electron density gradient reduce the value of the real frequency, in agreement with experimental observation. Nonlinear electron-scale gyrokinetic simulations show that high electron density gradient reduces electron heat flux and stiffness, and increases the ETG nonlinear threshold, consistent with experimental observations.« less

Compensatory selection for roads over natural linear features by wolves in northern Ontario: Implications for caribou conservation

PubMed Central

Patterson, Brent R.; Anderson, Morgan L.; Rodgers, Arthur R.; Vander Vennen, Lucas M.; Fryxell, John M.

2017-01-01

Woodland caribou (Rangifer tarandus caribou) in Ontario are a threatened species that have experienced a substantial retraction of their historic range. Part of their decline has been attributed to increasing densities of anthropogenic linear features such as trails, roads, railways, and hydro lines. These features have been shown to increase the search efficiency and kill rate of wolves. However, it is unclear whether selection for anthropogenic linear features is additive or compensatory to selection for natural (water) linear features which may also be used for travel. We studied the selection of water and anthropogenic linear features by 52 resident wolves (Canis lupus x lycaon) over four years across three study areas in northern Ontario that varied in degrees of forestry activity and human disturbance. We used Euclidean distance-based resource selection functions (mixed-effects logistic regression) at the seasonal range scale with random coefficients for distance to water linear features, primary/secondary roads/railways, and hydro lines, and tertiary roads to estimate the strength of selection for each linear feature and for several habitat types, while accounting for availability of each feature. Next, we investigated the trade-off between selection for anthropogenic and water linear features. Wolves selected both anthropogenic and water linear features; selection for anthropogenic features was stronger than for water during the rendezvous season. Selection for anthropogenic linear features increased with increasing density of these features on the landscape, while selection for natural linear features declined, indicating compensatory selection of anthropogenic linear features. These results have implications for woodland caribou conservation. Prey encounter rates between wolves and caribou seem to be strongly influenced by increasing linear feature densities. This behavioral mechanism–a compensatory functional response to anthropogenic linear feature density resulting in decreased use of natural travel corridors–has negative consequences for the viability of woodland caribou. PMID:29117234

Compensatory selection for roads over natural linear features by wolves in northern Ontario: Implications for caribou conservation.

PubMed

Newton, Erica J; Patterson, Brent R; Anderson, Morgan L; Rodgers, Arthur R; Vander Vennen, Lucas M; Fryxell, John M

2017-01-01

Woodland caribou (Rangifer tarandus caribou) in Ontario are a threatened species that have experienced a substantial retraction of their historic range. Part of their decline has been attributed to increasing densities of anthropogenic linear features such as trails, roads, railways, and hydro lines. These features have been shown to increase the search efficiency and kill rate of wolves. However, it is unclear whether selection for anthropogenic linear features is additive or compensatory to selection for natural (water) linear features which may also be used for travel. We studied the selection of water and anthropogenic linear features by 52 resident wolves (Canis lupus x lycaon) over four years across three study areas in northern Ontario that varied in degrees of forestry activity and human disturbance. We used Euclidean distance-based resource selection functions (mixed-effects logistic regression) at the seasonal range scale with random coefficients for distance to water linear features, primary/secondary roads/railways, and hydro lines, and tertiary roads to estimate the strength of selection for each linear feature and for several habitat types, while accounting for availability of each feature. Next, we investigated the trade-off between selection for anthropogenic and water linear features. Wolves selected both anthropogenic and water linear features; selection for anthropogenic features was stronger than for water during the rendezvous season. Selection for anthropogenic linear features increased with increasing density of these features on the landscape, while selection for natural linear features declined, indicating compensatory selection of anthropogenic linear features. These results have implications for woodland caribou conservation. Prey encounter rates between wolves and caribou seem to be strongly influenced by increasing linear feature densities. This behavioral mechanism-a compensatory functional response to anthropogenic linear feature density resulting in decreased use of natural travel corridors-has negative consequences for the viability of woodland caribou.

Diminished Reactivity of Postmature Human Infants to Sucrose Compared with Term Infants.

ERIC Educational Resources Information Center

Smith, Barbara A.; And Others

1992-01-01

This study of healthy 39-week-old infants, so-called term infants, and chronically stressed 42-week-old infants, so-called postmature infants, showed that sucrose was extremely effective in calming term infants but less effective in calming postmature infants. Results supported the hypothesis that sucrose engages an opioid system in infants. (BG)

21 CFR 172.869 - Sucrose oligoesters.

Code of Federal Regulations, 2012 CFR

2012-04-01

...-, hexa-, and hepta-esters Not less than 50% Do. Do. (4) Octa-esters Not more than 40% Do. Do. (5) Free Sucrose Not more than 0.5% “Free Sucrose Method,” issued by Mitsubishi Chemical Corp., June 17, 1998. Do..., Washington, DC 20418 (Internet: http://www.nap.edu). (7) Residue on Ignition Not more than 0.7% “Residue on...

21 CFR 172.869 - Sucrose oligoesters.

Code of Federal Regulations, 2013 CFR

2013-04-01

...-, hexa-, and hepta-esters Not less than 50% Do. Do. (4) Octa-esters Not more than 40% Do. Do. (5) Free Sucrose Not more than 0.5% “Free Sucrose Method,” issued by Mitsubishi Chemical Corp., June 17, 1998. Do..., Washington, DC 20418 (Internet: http://www.nap.edu). (7) Residue on Ignition Not more than 0.7% “Residue on...

Molecular cloning and expressional analysis of five sucrose transporter (SUT) genes in sugarcane

USDA-ARS?s Scientific Manuscript database

The sucrose transport and accumulation in sugarcane internodes are very complicated processes and how sugarcane sucrose transporter (SUT) genes function in these processes remains unclear. In this study, five sugarcane SUT genes, namely, SoSUT1, SoSUT2, SoSUT3, SoSUT4 and SoSUT5, were cloned and the...

Repeated Cocaine Experience Facilitates Sucrose-Reinforced Operant Responding in Enriched and Isolated Rats

ERIC Educational Resources Information Center

Klein, Emily D.; Gehrke, Brenda J.; Green, Thomas A.; Zentall, Thomas R.; Bardo, Michael T.

2007-01-01

The purpose of the present experiment was to determine whether repeated cocaine exposure differentially affects sucrose-reinforced operant responding in rats raised in an enriched condition (EC) or an isolated condition (IC). Specifically, the performance of EC and IC rats pressing a lever for sucrose under a high fixed-ratio schedule (FR 30)…

Sucrose Treated Carbon Nanotube and Graphene Yarns and Sheets

NASA Technical Reports Server (NTRS)

Sauti, Godfrey (Inventor); Kim, Jae-Woo (Inventor); Siochi, Emilie J. (Inventor); Wise, Kristopher E. (Inventor)

2017-01-01

Consolidated carbon nanotube or graphene yarns and woven sheets are consolidated through the formation of a carbon binder formed from the dehydration of sucrose. The resulting materials, on a macro-scale are lightweight and of a high specific modulus and/or strength. Sucrose is relatively inexpensive and readily available, and the process is therefore cost-effective.

Raffinose Induces Biofilm Formation by Streptococcus mutans in Low Concentrations of Sucrose by Increasing Production of Extracellular DNA and Fructan.

PubMed

Nagasawa, Ryo; Sato, Tsutomu; Senpuku, Hidenobu

2017-08-01

Streptococcus mutans is the primary etiological agent of dental caries and causes tooth decay by forming a firmly attached biofilm on tooth surfaces. Biofilm formation is induced by the presence of sucrose, which is a substrate for the synthesis of extracellular polysaccharides but not in the presence of oligosaccharides. Nonetheless, in this study, we found that raffinose, which is an oligosaccharide with an intestinal regulatory function and antiallergic effect, induced biofilm formation by S. mutans in a mixed culture with sucrose, which was at concentrations less than those required to induce biofilm formation directly. We analyzed the possible mechanism behind the small requirement for sucrose for biofilm formation in the presence of raffinose. Our results suggested that sucrose contributed to an increase in bacterial cell surface hydrophobicity and biofilm formation. Next, we examined how the effects of raffinose interacted with the effects of sucrose for biofilm formation. We showed that the presence of raffinose induced fructan synthesis by fructosyltransferase and aggregated extracellular DNA (eDNA, which is probably genomic DNA released from dead cells) into the biofilm. eDNA seemed to be important for biofilm formation, because the degradation of DNA by DNase I resulted in a significant reduction in biofilm formation. When assessing the role of fructan in biofilm formation, we found that fructan enhanced eDNA-dependent cell aggregation. Therefore, our results show that raffinose and sucrose have cooperative effects and that this induction of biofilm formation depends on supportive elements that mainly consist of eDNA and fructan. IMPORTANCE The sucrose-dependent mechanism of biofilm formation in Streptococcus mutans has been studied extensively. Nonetheless, the effects of carbohydrates other than sucrose are inadequately understood. Our findings concerning raffinose advance the understanding of the mechanism underlying the joint effects of sucrose and other carbohydrates on biofilm formation. Since raffinose has been reported to have positive effects on enterobacterial flora, research on the effects of raffinose on the oral flora are required prior to its use as a beneficial sugar for human health. Here, we showed that raffinose induced biofilm formation by S. mutans in low concentrations of sucrose. The induction of biofilm formation generally generates negative effects on the oral flora. Therefore, we believe that this finding will aid in the development of more effective oral care techniques to maintain oral flora health. Copyright © 2017 American Society for Microbiology.

Development of tuberous roots and sugar accumulation as related to invertase activity and mineral nutrition.

PubMed

Ricardo, C P; Sovia, D

1974-03-01

Sucrose storage in tuberous roots was not observed when the tissues had very high activities of acid invertase. High activities of the enzyme were always present in the roots at early stages of their development. In species where the activity of the enzyme decreased during root development, sucrose was stored. Thus, acid invertase was undetectable in mature roots of carrots (Daucus carota L.) where sucrose formed almost 80% of the dry matter. Conversely, radish (Raphanus sativus L.) and turnip (Brassica rapa L.) roots, in which the activity of the enzyme remained high until maturity, did not store appreciable amounts of sucrose (2% and 9%, respectively, of the dry matter in the mature roots), reducing sugars being the main reserve (more than 80% of the dry matter in mature turnips). The correlation between sucrose content and acid invertase activity was furthermore evident in both sucrose- and hexose-storing roots when the activity of this enzyme was affected by changes in the mineral nutrition. Deficiencies of nitrogen and sulphur reduced the activity of acid and alkaline invertases and led to increase in sucrose content and decrease in reducing sugars. However, the decline of alkaline invertase activity in tissues low in acid invertase had no clear effect on sugar content. Sodium chloride (10(-1)M) affected acid invertase and sugars in a manner similar to that of the two deficiencies, but had practically no effect on alkaline invertase. The changes in sugar content produced by the variations in mineral nutrition were small in hexose-storing roots in relation to those of sucrose-storing roots. It is possible that this result is related to the different levels of acid invertase in the two types of roots.

Influence of stimulus and oral adaptation temperature on gustatory responses in central taste-sensitive neurons

PubMed Central

Li, Jinrong

2015-01-01

The temperature of taste stimuli can modulate gustatory processing. Perceptual data indicate that the adapted temperature of oral epithelia also influences gustation, although little is known about the neural basis of this effect. Here, we electrophysiologically recorded orosensory responses (spikes) to 25°C (cool) and 35°C (warm) solutions of sucrose (0.1 and 0.3 M), NaCl (0.004, 0.1, and 0.3 M), and water from taste-sensitive neurons in the nucleus of the solitary tract in mice under varied thermal adaptation of oral epithelia. Conditions included presentation of taste stimuli isothermal to adaptation temperatures of 25°C (constant cooling) and 35°C (constant warming), delivery of 25°C stimuli following 35°C adaptation (relative cooling), and presentation of 35°C stimuli following 25°C adaptation (relative warming). Responses to sucrose in sucrose-oriented cells (n = 15) were enhanced under the constant and relative warming conditions compared with constant cooling, where contiguous cooling across adaptation and stimulus periods induced the lowest and longest latency responses to sucrose. Yet compared with constant warming, cooling sucrose following warm adaptation (relative cooling) only marginally reduced activity to 0.1 M sucrose and did not alter responses to 0.3 M sucrose. Thus, warmth adaptation counteracted the attenuation in sucrose activity associated with stimulus cooling. Analysis of sodium-oriented (n = 25) neurons revealed adaptation to cool water, and cooling taste solutions enhanced unit firing to 0.004 M (perithreshold) NaCl, whereas warmth adaptation and stimulus warming could facilitate activity to 0.3 M NaCl. The concentration dependence of this thermal effect may reflect a dual effect of temperature on the sodium reception mechanism that drives sodium-oriented cells. PMID:25673737

Radiosynthesis of 6’-Deoxy-6’[18F]Fluorosucrose via Automated Synthesis and Its Utility to Study In Vivo Sucrose Transport in Maize (Zea mays) Leaves

PubMed Central

Ying, Weijiang; Gaddam, Vikram; Harmata, Michael; Robertson, J. David; Swyers, Michael; Jurisson, Silvia S.

2015-01-01

Sugars produced from photosynthesis in leaves are transported through the phloem tissues within veins and delivered to non-photosynthetic organs, such as roots, stems, flowers, and seeds, to support their growth and/or storage of carbohydrates. However, because the phloem is located internally within the veins, it is difficult to access and to study the dynamics of sugar transport. Radioactive tracers have been extensively used to study vascular transport in plants and have provided great insights into transport dynamics. To better study sucrose partitioning in vivo, a novel radioactive analog of sucrose was synthesized through a completely chemical synthesis route by substituting fluorine-18 (half-life 110 min) at the 6’ position to generate 6’-deoxy-6’[18F]fluorosucrose (18FS). This radiotracer was then used to compare sucrose transport between wild-type maize plants and mutant plants lacking the Sucrose transporter1 (Sut1) gene, which has been shown to function in sucrose phloem loading. Our results demonstrate that 18FS is transported in vivo, with the wild-type plants showing a greater rate of transport down the leaf blade than the sut1 mutant plants. A similar transport pattern was also observed for universally labeled [U-14C]sucrose ([U-14C]suc). Our findings support the proposed sucrose phloem loading function of the Sut1 gene in maize, and additionally demonstrate that the 18FS analog is a valuable, new tool that offers imaging advantages over [U-14C]suc for studying phloem transport in plants. PMID:26024520

Interactive effects of chronic stress and a high-sucrose diet on nonalcoholic fatty liver in young adult male rats.

PubMed

Corona-Pérez, Adriana; Díaz-Muñoz, Mauricio; Cuevas-Romero, Estela; Luna-Moreno, Dalia; Valente-Godínez, Héctor; Vázquez-Martínez, Olivia; Martínez-Gómez, Margarita; Rodríguez-Antolín, Jorge; Nicolás-Toledo, Leticia

2017-11-01

Glucocorticoids have been implicated in nonalcoholic fatty liver diseases (NAFLD). The influence of a palatable diet on the response to stress is controversial. This study explored whether a high-sucrose diet could protect from hepatic steatosis induced by chronic restraint stress in young adult rats. Male Wistar rats aged 21 days were allocated into four groups (n = 6-8 per group): control, chronic restraint stress, 30% sucrose diet, and 30% sucrose diet plus chronic restraint stress. After being exposed to either tap water or sucrose solution during eight weeks, half of the rats belonging to each group were subject or not to repeated restraint stress (1 h per day, 5 days per week) during four weeks. Triacylglycerol (TAG), oxidative stress, activity of 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD-1), infiltration of immune cells, and glycogen amount in the liver were quantified. Serum concentrations of corticosterone and testosterone were also measured. The stressed group showed normal serum concentrations of corticosterone and did not have hepatic steatosis. However, this group showed increased glycogen, inflammation, mild fibrosis, oxidative stress, and a high activity of 11β-HSD-1 in the liver. The group exposed to the high-sucrose diet had lower concentrations of corticosterone, hepatic steatosis and moderate fibrosis. The group subject to high-sucrose diet plus chronic restraint stress showed low concentrations of corticosterone, hepatic steatosis, oxidative stress, and high concentrations of testosterone. Thus, restraint stress and a high-sucrose diet each generate different components of nonalcoholic fatty liver in young adult rats. The combination of both the factors could promote a faster development of NAFLD.

Low-dose prazosin alone and in combination with propranolol or naltrexone: effects on ethanol and sucrose seeking and self-administration in the P rat.

PubMed

Verplaetse, Terril L; Czachowski, Cristine L

2015-08-01

Evidence suggests that the noradrenergic system mediates ethanol reinforcement. However, preclinical studies suggest that noradrenergic antagonists block other oral reinforcers indicating possible unwanted secondary medication effects. This study examined combinations of low-dose prazosin with propranolol or naltrexone using a behavioral paradigm that separately assesses reinforcer seeking and self-administration. Male alcohol-preferring (P) rats (n = 20/experiment) were trained to complete a response requirement (RR) resulting in access to 1 % sucrose (n = 10) or 10 % ethanol (n = 10) for 20 min. Rats received vehicle, prazosin alone (0.125, 0.25, 0.5, and 1.0 mg/kg, intraperitoneally (IP)), or prazosin in combination with propranolol (5 mg/kg (IP); Exp. 1) or in combination with naltrexone (0.03 mg/kg, subcutaneously (SC); Exp. 2). For Exp. 1, prazosin alone effectively decreased sucrose seeking more than ethanol seeking, but decreased ethanol self-administration only. Propranolol alone effectively decreased ethanol seeking more than sucrose seeking and decreased ethanol intake only. At some dose combinations, there was a greater attenuation of ethanol and sucrose intake relative to either drug alone. For Exp. 2, prazosin alone and naltrexone alone were effective in decreasing ethanol seeking and intake only. Combination treatment was more effective than either drug alone at decreasing ethanol seeking and consumption and sucrose intake, but not sucrose seeking. Propranolol and naltrexone alone were specific to ethanol indicating that low doses of either medication may be beneficial in treating alcohol use disorders. Prazosin in combination with propranolol or naltrexone was more effective than either drug alone and also reduced sucrose-reinforced behaviors. These data suggest that the noradrenergic system is a viable target for developing treatment approaches for problem drinkers.

Low-Dose Prazosin Alone and in Combination with Propranolol or Naltrexone: Effects on Ethanol- and Sucrose-Seeking and Self-Administration in the P Rat

PubMed Central

Verplaetse, Terril L.; Czachowski, Cristine L.

2015-01-01

Rationale Evidence suggests that the noradrenergic system mediates ethanol-reinforcement. However, preclinical studies suggest that noradrenergic antagonists block other oral reinforcers indicating possible unwanted secondary medication effects. Methods This study examined combinations of low-dose prazosin with propranolol or naltrexone using a behavioral paradigm that separately assesses reinforcer-seeking and self-administration. Male alcohol-preferring (P) rats (n=20/experiment) were trained to complete a response requirement (RR) resulting in access to 1% sucrose (n=10) or 10% ethanol (n=10) for 20min. Rats received vehicle, prazosin alone (0.125, 0.25, 0.5, 1.0 mg/kg; intraperitoneally (IP)) or prazosin in combination with propranolol (5 mg/kg (IP); Exp1) or in combination with naltrexone (0.03 mg/kg (subcutaneously (SC); Exp2). Results For Exp1, prazosin alone effectively decreased sucrose-seeking more than ethanol-seeking, but decreased ethanol self-administration only. Propranolol alone effectively decreased ethanol-seeking more than sucrose-seeking and decreased ethanol intake only. At some dose combinations, there was a greater attenuation of ethanol and sucrose intake relative to either drug alone. For Exp2, prazosin alone and naltrexone alone were effective in decreasing ethanol-seeking and intake only. Combination treatment was more effective than either drug alone at decreasing ethanol-seeking and consumption and sucrose intake, but not sucrose-seeking. Conclusions Propranolol and naltrexone alone were specific to ethanol indicating that low doses of either medication may be beneficial in treating alcohol use disorders. Prazosin in combination with propranolol or naltrexone was more effective than either drug alone, but also reduced sucrose-reinforced behaviors. These data suggest that the noradrenergic system is a viable target for developing treatment approaches for problem drinkers. PMID:25743758

Comparative evaluation of Nano-Hydroxyapatite preparation and Calcium Sucrose Phosphate on microhardness of deciduous teeth after iron drop exposure - An in-vitro study.

PubMed

Rathi, Nilesh; Baid, Rutika; Baliga, Sudhindra; Thosar, Nilima

2017-04-01

To evaluate and compare the microhardness of deciduous teeth treated with nano-hydroxyapatite and calcium sucrose phosphate after iron drop exposure. Twenty healthy anterior deciduous teeth were collected and stored in 0.9% saline solution at room temperature. All the teeth were immersed in artificial saliva in an incubator shaker at 37° for an hour and then subjected to Vickers microhardness test at 100g load for 5 seconds. The teeth were then immersed in iron drop for 5 minutes, twice daily, rinsed with distilled water and kept in artificial saliva. This procedure was repeated for 7 days and teeth were subjected to microhardness testing. Further, the teeth were divided in two groups, each group containing 10 teeth. In group I, nanohydroxyapatite preparation and in group II, calcium sucrose phosphate were applied for 10 minutes, twice daily for 7 days and subjected again to microhardness testing again. Vickers microhardness analysis revealed that iron drop exposure to teeth caused significant decrease in microhardness ( p <0.05). Application of nanohydroxyapatite preparation in Group I showed significantly increased enamel microhardness (206.90) than that after iron drop exposure. Similarly, application of calcium sucrose phosphate in Group II showed significantly increased enamel microhardness (200.89) than that after iron drop exposure. Statistical difference was seen between the two groups, with nanohydroxyapatite preparation showing increased microhardness than calcium sucrose phosphate. Nanohydroxyapatite preparation and calcium sucrose phosphate have remineralizing effect over teeth affected by acid challenge of iron drops, nanohydroxyapatite preparation showing better results than calcium sucrose phosphate. Key words: Iron drops, Nanohydroxyapaptite, calcium sucrose phosphate, anticay.

Transcription factors, sucrose, and sucrose metabolic genes interact to regulate potato phenylpropanoid metabolism

PubMed Central

Payyavula, Raja S.; Navarre, Duroy A.

2013-01-01

Much remains unknown about how transcription factors and sugars regulate phenylpropanoid metabolism in tuber crops like potato (Solanum tuberosum). Based on phylogeny and protein similarity to known regulators of phenylpropanoid metabolism, 15 transcription factors were selected and their expression was compared in white, yellow, red, and purple genotypes with contrasting phenolic and anthocyanin profiles. Red and purple genotypes had increased phenylalanine ammonia lyase (PAL) enzyme activity, markedly higher levels of phenylpropanoids, and elevated expression of most phenylpropanoid structural genes, including a novel anthocyanin O-methyltransferase. The transcription factors Anthocyanin1 (StAN1), basic Helix Loop Helix1 (StbHLH1), and StWD40 were more strongly expressed in red and purple potatoes. Expression of 12 other transcription factors was not associated with phenylpropanoid content, except for StMYB12B, which showed a negative relationship. Increased expression of AN1, bHLH1, and WD40 was also associated with environmentally mediated increases in tuber phenylpropanoids. Treatment of potato plantlets with sucrose induced hydroxycinnamic acids, flavonols, anthocyanins, structural genes, AN1, bHLH1, WD40, and genes encoding the sucrose-hydrolysing enzymes SUSY1, SUSY4, and INV2. Transient expression of StAN1 in tobacco leaves induced bHLH1, structural genes, SUSY1, SUSY4, and INV1, and increased phenylpropanoid amounts. StAN1 infiltration into tobacco leaves decreased sucrose and glucose concentrations. In silico promoter analysis revealed the presence of MYB and bHLH regulatory elements on sucrolytic gene promoters and sucrose-responsive elements on the AN1 promoter. These findings reveal an interesting dynamic between AN1, sucrose, and sucrose metabolic genes in modulating potato phenylpropanoids. PMID:24098049

Social defeat-induced anhedonia: effects on operant sucrose-seeking behavior

PubMed Central

Riga, Danai; Theijs, J. Trisna; De Vries, Taco J.; Smit, August B.; Spijker, Sabine

2015-01-01

Reduced capacity to experience pleasure, also known as anhedonia, is a key feature of the depressive state and is associated with poor disease prognosis and treatment outcome. Various behavioral readouts (e.g., reduced sucrose intake) have been employed in animal models of depression as a measure of anhedonia. However, several aspects of anhedonia are poorly represented within the repertoire of current preclinical assessments. We recently adopted the social defeat-induced persistent stress (SDPS) paradigm that models a maintained depressive-like state in the rat, including social withdrawal and deficits in short-term spatial memory. Here we investigated whether SDPS elicited persistent deficits in natural reward evaluation, as part of anhedonia. We examined cue-paired operant sucrose self-administration, enabling us to study acquisition, motivation, extinction, and relapse to sucrose seeking following SDPS. Furthermore, we addressed whether guanfacine, an α2-adrenergic agonist that reduces stress-triggered maladaptive behavioral responses to drugs of abuse, could relief from SDPS-induced anhedonia. SDPS, consisting of five social defeat episodes followed by prolonged (≥8 weeks) social isolation, did not affect sucrose consumption during acquisition of self-administration. However, it strongly enhanced the motivational drive to acquire a sucrose reward in progressive ratio training. Moreover, SDPS induced initial resilience to extinction and rendered animals more sensitive to cue-induced reinstatement of sucrose-seeking. Guanfacine treatment attenuated SDPS-induced motivational overdrive and limited reinstatement of sucrose seeking, normalizing behavior to control levels. Together, our data indicate that long after the termination of stress exposure, SDPS induces guanfacine-reversible deficits in evaluation of a natural reward. Importantly, the SDPS-triggered anhedonia reflects many aspects of the human phenotype, including impaired motivation and goal-directed conduct. PMID:26300748

Social defeat-induced anhedonia: effects on operant sucrose-seeking behavior.

PubMed

Riga, Danai; Theijs, J Trisna; De Vries, Taco J; Smit, August B; Spijker, Sabine

2015-01-01

Reduced capacity to experience pleasure, also known as anhedonia, is a key feature of the depressive state and is associated with poor disease prognosis and treatment outcome. Various behavioral readouts (e.g., reduced sucrose intake) have been employed in animal models of depression as a measure of anhedonia. However, several aspects of anhedonia are poorly represented within the repertoire of current preclinical assessments. We recently adopted the social defeat-induced persistent stress (SDPS) paradigm that models a maintained depressive-like state in the rat, including social withdrawal and deficits in short-term spatial memory. Here we investigated whether SDPS elicited persistent deficits in natural reward evaluation, as part of anhedonia. We examined cue-paired operant sucrose self-administration, enabling us to study acquisition, motivation, extinction, and relapse to sucrose seeking following SDPS. Furthermore, we addressed whether guanfacine, an α2-adrenergic agonist that reduces stress-triggered maladaptive behavioral responses to drugs of abuse, could relief from SDPS-induced anhedonia. SDPS, consisting of five social defeat episodes followed by prolonged (≥8 weeks) social isolation, did not affect sucrose consumption during acquisition of self-administration. However, it strongly enhanced the motivational drive to acquire a sucrose reward in progressive ratio training. Moreover, SDPS induced initial resilience to extinction and rendered animals more sensitive to cue-induced reinstatement of sucrose-seeking. Guanfacine treatment attenuated SDPS-induced motivational overdrive and limited reinstatement of sucrose seeking, normalizing behavior to control levels. Together, our data indicate that long after the termination of stress exposure, SDPS induces guanfacine-reversible deficits in evaluation of a natural reward. Importantly, the SDPS-triggered anhedonia reflects many aspects of the human phenotype, including impaired motivation and goal-directed conduct.

Effects of stevia, aspartame, and sucrose on food intake, satiety, and postprandial glucose and insulin levels

PubMed Central

Anton, Stephen D.; Martin, Corby K.; Han, Hongmei; Coulon, Sandra; Cefalu, William T.; Geiselman, Paula; Williamson, Donald A.

2010-01-01

Consumption of sugar-sweetened beverages may be one of the dietary causes of metabolic disorders, such as obesity. Therefore, substituting sugar with low-calorie sweeteners may be an efficacious weight management strategy. We tested the effect of preloads containing stevia, aspartame, or sucrose on food intake, satiety, and postprandial glucose and insulin levels. Design: 19 healthy lean (BMI = 20.0 – 24.9) and 12 obese (BMI = 30.0 – 39.9) individuals 18 to 50 years old completed three separate food test days during which they received preloads containing stevia (290 kcal), aspartame (290 kcal), or sucrose (493 kcal) before the lunch and dinner meal. The preload order was balanced, and food intake (kcal) was directly calculated. Hunger and satiety levels were reported before and after meals, and every hour throughout the afternoon. Participants provided blood samples immediately before and 20 minutes after the lunch preload. Despite the caloric difference in preloads (290 vs. 493 kcals), participants did not compensate by eating more at their lunch and dinner meals when they consumed stevia and aspartame versus sucrose in preloads (mean differences in food intake over entire day between sucrose and stevia = 301 kcal, p < .01; aspartame = 330 kcal, p < .01). Self-reported hunger and satiety levels did not differ by condition. Stevia preloads significantly lowered postprandial glucose levels compared to sucrose preloads (p < .01), and postprandial insulin levels compared to both aspartame and sucrose preloads (p < .05). When consuming stevia and aspartame preloads, participants did not compensate by eating more at either their lunch or dinner meal and reported similar levels of satiety compared to when they consumed the higher calorie sucrose preload. PMID:20303371

Short-term effects of glucose and sucrose on cognitive performance and mood in elderly people.

PubMed

van der Zwaluw, Nikita L; van de Rest, Ondine; Kessels, Roy P C; de Groot, Lisette C P G M

2014-01-01

In this study we determined the short-term effects of a glucose drink and a sucrose drink compared to a placebo on cognitive performance and mood in elderly people with subjective, mild memory complaints using a randomized crossover study design. In total, 43 nondiabetic older adults with self-reported memory complaints were included. Drinks consisted of 250 ml with dissolved glucose (50 g), sucrose (100 g), or a mixture of artificial sweeteners (placebo). Multiple neuropsychological tests were performed and were combined by means of z scores into four cognitive domains: episodic memory, working memory, attention and information (processing speed), and executive functioning. Mood was assessed with the short Profile of Mood Status (s-POMS) questionnaire. Blood glucose concentrations were measured at five time points to divide participants into those with a better or poorer blood glucose recovery. Performance on the domain of attention and information processing speed was significantly better after consuming the sucrose drink (domain score of 0.06, SD = 0.91) than after the placebo drink (-0.08, SD = 0.92, p = .04). Sucrose had no effect on the other three domains, and glucose had no effect on any of the domains compared to the placebo. When dividing participants into poorer or better glucose recoverers, the beneficial effect of sucrose on attention and information processing speed was only seen in participants with a poorer recovery. After sucrose consumption, depressive feelings and tension were slightly higher than after the placebo. To conclude, 100 g sucrose, but not 50 g glucose, optimized attention and information processing speed in the short term in this study in elderly people with subjective, mild memory complaints.

Effects of stevia, aspartame, and sucrose on food intake, satiety, and postprandial glucose and insulin levels.

PubMed

Anton, Stephen D; Martin, Corby K; Han, Hongmei; Coulon, Sandra; Cefalu, William T; Geiselman, Paula; Williamson, Donald A

2010-08-01

Consumption of sugar-sweetened beverages may be one of the dietary causes of metabolic disorders, such as obesity. Therefore, substituting sugar with low calorie sweeteners may be an efficacious weight management strategy. We tested the effect of preloads containing stevia, aspartame, or sucrose on food intake, satiety, and postprandial glucose and insulin levels. 19 healthy lean (BMI=20.0-24.9) and 12 obese (BMI=30.0-39.9) individuals 18-50 years old completed three separate food test days during which they received preloads containing stevia (290kcal), aspartame (290kcal), or sucrose (493kcal) before the lunch and dinner meal. The preload order was balanced, and food intake (kcal) was directly calculated. Hunger and satiety levels were reported before and after meals, and every hour throughout the afternoon. Participants provided blood samples immediately before and 20min after the lunch preload. Despite the caloric difference in preloads (290kcal vs. 493kcal), participants did not compensate by eating more at their lunch and dinner meals when they consumed stevia and aspartame versus sucrose in preloads (mean differences in food intake over entire day between sucrose and stevia=301kcal, p<.01; aspartame=330kcal, p<.01). Self-reported hunger and satiety levels did not differ by condition. Stevia preloads significantly reduced postprandial glucose levels compared to sucrose preloads (p<.01), and postprandial insulin levels compared to both aspartame and sucrose preloads (p<.05). When consuming stevia and aspartame preloads, participants did not compensate by eating more at either their lunch or dinner meal and reported similar levels of satiety compared to when they consumed the higher calorie sucrose preload. Published by Elsevier Ltd.

Differences in bingeing behavior and cocaine reward following intermittent access to sucrose, glucose or fructose solutions

PubMed Central

Rorabaugh, Jacki M.; Stratford, Jennifer M.; Zahniser, Nancy R.

2015-01-01

Daily intermittent access to sugar solutions results in intense bouts of sugar intake (i.e. bingeing) in rats. Bingeing on sucrose, a disaccharide of glucose and fructose, has been associated with a “primed” mesolimbic dopamine (DA) pathway. Recent studies suggest glucose and fructose engage brain reward and energy sensing mechanisms in opposing ways and may drive sucrose intake through unique neuronal circuits. Here, we examined in male Sprague-Dawley rats whether or not (1) intermittent access to isocaloric solutions of sucrose, glucose or fructose results in distinctive sugar bingeing profiles and (2) previous sugar bingeing alters cocaine locomotor activation and/or reward, as determined by conditioned place preference (CPP). To encourage bingeing, rats were given 24-h access to water and 12 h-intermittent access to chow plus an intermittent bottle that contained water (control) or 8% solutions of sucrose, glucose or fructose for 9 days, followed by ad libitum chow diet and a 10 day cocaine (15 mg/kg; i.p.) CPP paradigm. By day 4 of the sugar bingeing diet, sugar bingeing in the fructose group surpassed the glucose group, with the sucrose group being intermediate. All three sugar groups had similar chow and water intake throughout the diet. In contrast, controls exhibited chow bingeing by day 5 without altering water intake. Similar magnitudes of cocaine CPP were observed in rats with a history of sucrose, fructose or chow (control) bingeing. Notably, the glucosebingeing rats did not demonstrate a significant cocaine CPP despite showing similar cocaine-induced locomotor activity as the other diet groups. Overall, these results show that fructose and glucose, the monosaccharide components of sucrose, produce divergent degrees of bingeing and cocaine reward. PMID:26079112

The ghrelin signalling system is involved in the consumption of sweets.

PubMed

Landgren, Sara; Simms, Jeffrey A; Thelle, Dag S; Strandhagen, Elisabeth; Bartlett, Selena E; Engel, Jörgen A; Jerlhag, Elisabet

2011-03-23

The gastric-derived orexigenic peptide ghrelin affects brain circuits involved in energy balance as well as in reward. Indeed, ghrelin activates an important reward circuit involved in natural- as well as drug-induced reward, the cholinergic-dopaminergic reward link. It has been hypothesized that there is a common reward mechanism for alcohol and sweet substances in both animals and humans. Alcohol dependent individuals have higher craving for sweets than do healthy controls and the hedonic response to sweet taste may, at least in part, depend on genetic factors. Rat selectively bred for high sucrose intake have higher alcohol consumption than non-sucrose preferring rats and vice versa. In the present study a group of alcohol-consuming individuals selected from a population cohort was investigated for genetic variants of the ghrelin signalling system in relation to both their alcohol and sucrose consumption. Moreover, the effects of GHS-R1A antagonism on voluntary sucrose-intake and operant self-administration, as well as saccharin intake were investigated in preclinical studies using rodents. The effects of peripheral grelin administration on sucrose intake were also examined. Here we found associations with the ghrelin gene haplotypes and increased sucrose consumption, and a trend for the same association was seen in the high alcohol consumers. The preclinical data show that a GHS-R1A antagonist reduces the intake and self-administration of sucrose in rats as well as saccharin intake in mice. Further, ghrelin increases the intake of sucrose in rats. Collectively, our data provide a clear indication that the GHS-R1A antagonists reduces and ghrelin increases the intake of rewarding substances and hence, the central ghrelin signalling system provides a novel target for the development of drug strategies to treat addictive behaviours.

Biosynthesis of levan, a bacterial extracellular polysaccharide, in the yeast Saccharomyces cerevisiae.

PubMed

Franken, Jaco; Brandt, Bianca A; Tai, Siew L; Bauer, Florian F

2013-01-01

Levans are fructose polymers synthesized by a broad range of micro-organisms and a limited number of plant species as non-structural storage carbohydrates. In microbes, these polymers contribute to the formation of the extracellular polysaccharide (EPS) matrix and play a role in microbial biofilm formation. Levans belong to a larger group of commercially important polymers, referred to as fructans, which are used as a source of prebiotic fibre. For levan, specifically, this market remains untapped, since no viable production strategy has been established. Synthesis of levan is catalysed by a group of enzymes, referred to as levansucrases, using sucrose as substrate. Heterologous expression of levansucrases has been notoriously difficult to achieve in Saccharomyces cerevisiae. As a strategy, this study used an invertase (Δsuc2) null mutant and two separate, engineered, sucrose accumulating yeast strains as hosts for the expression of the levansucrase M1FT, previously cloned from Leuconostoc mesenteroides. Intracellular sucrose accumulation was achieved either by expression of a sucrose synthase (Susy) from potato or the spinach sucrose transporter (SUT). The data indicate that in both Δsuc2 and the sucrose accumulating strains, the M1FT was able to catalyse fructose polymerisation. In the absence of the predicted M1FT secretion signal, intracellular levan accumulation was significantly enhanced for both sucrose accumulation strains, when grown on minimal media. Interestingly, co-expression of M1FT and SUT resulted in hyper-production and extracellular build-up of levan when grown in rich medium containing sucrose. This study presents the first report of levan production in S. cerevisiae and opens potential avenues for the production of levan using this well established industrial microbe. Furthermore, the work provides interesting perspectives when considering the heterologous expression of sugar polymerizing enzymes in yeast.

Growth medium alterations improve in vitro cold storage of pear germplasm.

PubMed

Kovalchuk, I; Zhumagulova, Z; Turdiev, T; Reed, B M

2014-01-01

Development of new fruit cultivars is dependent on genetic resource collections such as those at the Pomological Garden of the Institute of Horticulture and Viticulture near Almaty, Kazakhstan. The pear germplasm collection of the Pomological Garden contains 615 cultivars and three species. In vitro cold storage of the collection would provide additional security to the field collection. This study was designed to improve medium-term in vitro storage of pear germplasm. Shoots of seven pear cultivars (Pyrus communis L.) were stored in plastic five-section bags at 4 degree C and a 10-h photoperiod (7 μmol/m2/s). Treatments included medium with four carbohydrate sources (3% sucrose, 2% or 3% mannitol, or 2% sucrose + 2% mannitol) with 0.5 mg/l BAP and 0.1 mg/l IBA or without plant growth regulators (PGRs) and at three Murashige and Skoog (MS) nitrogen concentrations (100%, 50% or 25%). Pear shoots remained viable for 9 to 15 months without repropagation on the control MS medium with 3% sucrose without PGRs. There were significant impacts of cultivar and treatment on the duration of cold storage. Shoots of 'Mramornaya' remained viable (rating of ≥ 2) for 27 months with PGRs and 2% sucrose + 2% mannitol compared to 12 months for the PGR + 3% sucrose treatment. Talgarskaya Krasaviza stored for 18 months on 2% sucrose + 2% mannitol while all other treatments lasted only 6 to 9 months. Treatments with 0.5 or 1 mg/l abscisic acid (ABA) with 3% sucrose increased storage duration as did reducing the concentration of nitrogen in the medium to 25% without PGRs and with 3% sucrose.

The Ghrelin Signalling System Is Involved in the Consumption of Sweets

PubMed Central

Landgren, Sara; Simms, Jeffrey A.; Thelle, Dag S.; Strandhagen, Elisabeth; Bartlett, Selena E.; Engel, Jörgen A.; Jerlhag, Elisabet

2011-01-01

The gastric-derived orexigenic peptide ghrelin affects brain circuits involved in energy balance as well as in reward. Indeed, ghrelin activates an important reward circuit involved in natural- as well as drug-induced reward, the cholinergic-dopaminergic reward link. It has been hypothesized that there is a common reward mechanism for alcohol and sweet substances in both animals and humans. Alcohol dependent individuals have higher craving for sweets than do healthy controls and the hedonic response to sweet taste may, at least in part, depend on genetic factors. Rat selectively bred for high sucrose intake have higher alcohol consumption than non-sucrose preferring rats and vice versa. In the present study a group of alcohol-consuming individuals selected from a population cohort was investigated for genetic variants of the ghrelin signalling system in relation to both their alcohol and sucrose consumption. Moreover, the effects of GHS-R1A antagonism on voluntary sucrose- intake and operant self-administration, as well as saccharin intake were investigated in preclinical studies using rodents. The effects of peripheral grelin administration on sucrose intake were also examined. Here we found associations with the ghrelin gene haplotypes and increased sucrose consumption, and a trend for the same association was seen in the high alcohol consumers. The preclinical data show that a GHS-R1A antagonist reduces the intake and self-administration of sucrose in rats as well as saccharin intake in mice. Further, ghrelin increases the intake of sucrose in rats. Collectively, our data provide a clear indication that the GHS-R1A antagonists reduces and ghrelin increases the intake of rewarding substances and hence, the central ghrelin signalling system provides a novel target for the development of drug strategies to treat addictive behaviours. PMID:21448464

Role of relaxin-3/RXFP3 system in stress-induced binge-like eating in female rats.

PubMed

Calvez, Juliane; de Ávila, Camila; Matte, Louis-Olivier; Guèvremont, Geneviève; Gundlach, Andrew L; Timofeeva, Elena

2016-03-01

Binge eating is frequently stimulated by stress. The neuropeptide relaxin-3 (RLN3) and its native receptor RXFP3 are implicated in stress and appetitive behaviors. We investigated the dynamics of the central RLN3/RXFP3 system in a newly established model of stress-induced binge eating. Female Sprague-Dawley rats were subjected to unpredictable intermittent 1-h access to 10% sucrose. When sucrose intake stabilized, rats were assessed for consistency of higher or lower sucrose intake in response to three unpredictable episodes of foot-shock stress; and assigned as binge-like eating prone (BEP) or binge-like eating resistant (BER). BEP rats displayed elevated consumption of sucrose under non-stressful conditions (30% > BER) and an additional marked increase in sucrose intake (60% > BER) in response to stress. Conversely, sucrose intake in BER rats was unaltered by stress. Chow intake was similar in both phenotypes on 'non-stress' days, but was significantly reduced by stress in BER, but not BEP, rats. After stress, BEP, but not BER, rats displayed a significant increase in RLN3 mRNA levels in the nucleus incertus. In addition, in response to stress, BEP, but not BER, rats had increased RXFP3 mRNA levels in the paraventricular and supraoptic nuclei of the hypothalamus. Intracerebroventricular administration of a selective RXFP3 antagonist, R3(B1-22)R, blocked the stress-induced increase in sucrose intake in BEP rats and had no effect on sucrose intake in BER rats. These results provide important evidence for a role of the central RLN3/RXFP3 system in the regulation of stress-induced binge eating in rats, and have therapeutic implications for eating disorders. Copyright © 2015 Elsevier Ltd. All rights reserved.

Intravenous gestational nicotine exposure results in increased motivation for sucrose reward in adult rat offspring.

PubMed

Lacy, Ryan T; Hord, Lauren L; Morgan, Amanda J; Harrod, Steven B

2012-08-01

Prenatal tobacco smoke exposure is associated with alterations in motivated behavior in offspring, such as increased consumption of highly palatable foods and abused drugs. Animal models show that gestational nicotine (GN) exposure mediates changes in responding for sucrose and drug reward. A novel, intermittent low-dose intravenous (IV) exposure model was used to administer nicotine (0.05 mg/kg/injection) or saline 3×/day to rats on gestational days 8-21. Two experiments investigated the effect of IV GN on (1) the habituation of spontaneous locomotor activity and on (2) sucrose reinforced responding in offspring. For the operant experiments, animals acquired fixed-ratio (FR-3) responding for sucrose, 26% (w/v), and were tested on varying concentrations (0, 3, 10, 30, and 56%; Latin-square) according to a FR-3, and then a progressive-ratio (PR) schedule. Male and female adult offspring were used. IV GN did not alter birth or growth weight, or the number of pups born. No between-group differences in habituation to spontaneous locomotor activity were observed. FR testing produced an inverted U-shaped response curve, and rats showed peak responding for 10% sucrose reinforcement. Neither gestation nor sex affected responding, suggesting equivalent sensitivity to varying sucrose concentrations. PR testing revealed that GN rats showed greater motivation for sucrose reinforcement relative to controls. A low-dose, IV GN exposure model resulted in increased motivation to respond for sucrose reinforcement in adult offspring. This suggests that using a low number of cigarettes throughout pregnancy will result in increased motivation for highly palatable foods in adult, and perhaps, adolescent offspring. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Effect of sucrose availability on wheel-running as an operant and as a reinforcing consequence on a multiple schedule: Additive effects of extrinsic and automatic reinforcement.

PubMed

Belke, Terry W; Pierce, W David

2015-07-01

As a follow up to Belke and Pierce's (2014) study, we assessed the effects of repeated presentation and removal of sucrose solution on the behavior of rats responding on a two-component multiple schedule. Rats completed 15 wheel turns (FR 15) for either 15% or 0% sucrose solution in the manipulated component and lever pressed 10 times on average (VR 10) for an opportunity to complete 15 wheel turns (FR 15) in the other component. In contrast to our earlier study, the components advanced based on time (every 8min) rather than completed responses. Results showed that in the manipulated component wheel-running rates were higher and the latency to initiate running longer when sucrose was present (15%) compared to absent (0% or water); the number of obtained outcomes (sucrose/water), however, did not differ with the presentation and withdrawal of sucrose. For the wheel-running as reinforcement component, rates of wheel turns, overall lever-pressing rates, and obtained wheel-running reinforcements were higher, and postreinforcement pauses shorter, when sucrose was present (15%) than absent (0%) in manipulated component. Overall, our findings suggest that wheel-running rate regardless of its function (operant or reinforcement) is maintained by automatically generated consequences (automatic reinforcement) and is increased as an operant by adding experimentally arranged sucrose reinforcement (extrinsic reinforcement). This additive effect on operant wheel-running generalizes through induction or arousal to the wheel-running as reinforcement component, increasing the rate of responding for opportunities to run and the rate of wheel-running per opportunity. Copyright © 2015 Elsevier B.V. All rights reserved.

Survival analysis: A consumer-friendly method to estimate the optimum sucrose level in probiotic petit suisse.

PubMed

Esmerino, E A; Paixão, J A; Cruz, A G; Garitta, L; Hough, G; Bolini, H M A

2015-11-01

For years, just-about-right (JAR) scales have been among the most used techniques to obtain sensory information about consumer perception, but recently, some researchers have harshly criticized the technique. The present study aimed to apply survival analysis to estimate the optimum sucrose concentration in probiotic petit suisse cheese and compare the survival analysis to JAR scales to verify which technique more accurately predicted the optimum sucrose concentration according to consumer acceptability. Two panels of consumers (total=170) performed affective tests to determine the optimal concentration of sucrose in probiotic petit suisse using 2 different methods of analysis: JAR scales (n=85) and survival analysis (n=85). Then an acceptance test was conducted using naïve consumers (n=100) between 18 and 60 yr old, with 2 samples of petit suisse, one with the ideal sucrose determined by JAR scales and the other with the ideal sucrose content determined by survival analysis, to determine which formulation was in accordance with consumer acceptability. The results indicate that the 2 sensory methods were equally effective in predicting the optimum sucrose level in probiotic petit suisse cheese, and no significant differences were detected in any of the characteristics related to liking evaluated. However, survival analysis has important advantages over the JAR scales. Survival analysis has shown the potential to be an advantageous tool for dairy companies because it was able to accurately predict the optimum sucrose content in a consumer-friendly way and was also practical for researchers because experimental sensory work is simpler and has been shown to be more cost effective than JAR scales without losses of consumer acceptability. Copyright © 2015 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.