[Contamination of sugar cane by 2 bird poisons: fenthion and cyanophos. Evaluation of residues in sugar cane juice transformed into sugar].
Explore the source record for details and available documents.
Animals↗
SEARCH · Search PubMed
Results for “SUGARS”
Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
Analysis of pyridylaminated O-linked sugar chains by two-dimensional sugar mapping.
Two-dimensional HPLC mapping of O-linked sugar chains was studied. Twenty-seven pyridylamino (PA-) derivatives of O-linked sugar chains liberated from glycoproteins by hydrazinolysis-N-acetylation were separated by reversed-phase and size-fractionation HPLC. Combining the elution positions obtained by these two HPLC techniques allows the construction of a two-dimensional sugar map which can be used to analyze the structure of PA-O-linked sugar chains. As in the case of PA-N-linked sugar chains, the additivity rule which correlates chemical structures with elution positions was also found in the case of PA-O-linked sugar chains. This separation system was effectively applied to the elucidation of minute amounts of PA-O-linked oligosaccharides.
Aminopyridines↗
Nucleic acid and protein elimination during the sugar manufacturing process of conventional and transgenic sugar beets.
The fate of cellular DNA during the standard purification steps of the sugar manufacturing process from conventional and transgenic sugar beets was determined. Indigenous nucleases of sugar beet cells were found to be active during the first extraction step (raw juice production) which was carried out at 70 degrees C. This and the consecutive steps of the manufacturing process were validated in terms of DNA degradation by competitive PCR of added external DNA. Each step of the process proved to be very efficient in the removal of nucleic acids. Taken together, the purification steps have the potential to reduce the amount of DNA by a factor of > 10(14), exceeding by far the total amount of DNA present in sugar beets. Furthermore, the gene products of the transgenes neomycin phosphotransferase and BNYVV (rhizomania virus) coat protein CP21 were shown to be removed during the purification steps, so that they could not be detected in the resulting white sugar. Thus, sugar obtained from conventional and transgenic beets is indistinguishable or substantially equivalent with respect to purity.
Base Sequence↗
[Studies on the various sugar-urea and sugar-starch-urea relationships with reference to the fermentation in the rumen and the digestibility of nutrients in fattening cattle].
Recommendations are given saying that sugar-to-crude fibre rations of not more than 1.7:1 and sugar-to-urea ratios of 12:1 should be used in the fattening of cattle fed urea-supplemented rations of roughages in which 40% to 50% of the crude protein content of the ration had been replaced by urea. The amount of sugar per kg live-weight should not exceed 4 g. Higher quantities reduce the digestibility of crude fibre and, additionally, decrease the NH3 level and the pH in the rumen. At the same time the amount of volatile fatty acids is increased while the content of ruminal acetic acid decreases. Variations in the sugar-to-starch ratio had no statistically significant influence on the nitrogen balance whereas it was found that increasing quantities of sugar significantly decreased the digestibility of crude fibre. The proportional content of sugar in the readily metabolisable carbohydrates contained in the ration should not exceed 20% to 50%.
Animal Feed↗
Possible pathway for the processing of sugar chains containing xylose in plant glycoproteins deduced on structural analyses of sugar chains from Ricinus communis lectins.
The structures of sugar chains from two lectins in seeds of the castor bean (Ricinus communis) were identified. The sugar chains were liberated from the lectins by hydrazinolysis. After N-acetylation, the reducing-end residues of the sugar chains were coupled with 2-aminopyridine. The pyridylamino derivatives thus obtained were purified by gel filtration and HPLC. The structures of the purified derivatives were identified by component sugar analysis, stepwise exoglycosidase digestion, partial acetolysis, and 500 MHz 1H-NMR spectroscopy. A new processing pathway for sugar chains in plant glycoproteins was proposed on the basis of the structures of the sugar chains.
Carbohydrate Sequence↗
Influence of specific dietary sugars on the jejunal mechanisms for glucose, galactose, and alpha-methyl glucoside absorption: evidence for multiple sugar carriers.
The effects of feeding glucose, galactose, and alpha-methyl glucoside on the kinetics of absorption of these sugars in the jejunum of the fasting rat were assessed by recently developed chemical and electrical methods for characterizing the electrogenic active transfer mechanisms in vivo. The parameters of 'apparent Km' (an index of carrier affinity) and Vmax (an index of the maximum jejunal transfer capacity) were obtained from the kinetic data to describe quantitatively the active transport mechanisms in rats fed their normal solid diet, in rats deprived of solid food for three days, and in rats deprived of solid food but allowed ad libitum access to isotonic solutions of glucose, galactose, or alpha-methyl glucoside for up to three days. Feeding the sugars to fasting rats produced complex differential effects on the 'apparent Km's' and Vmax's of the various transport mechanisms. The changes, although complex, can best be explained by alterations in the transport mechanisms per se rather than by non-specific changes in intestinal morphology or metabolism. The differential effects induced by the feeding sugars are further evidence for the concept that jejunal enterocytes possess multiple carriers or mechansims for the absorption of actively transported sugars in vivo. The multiple forms of the sugar carriers (isocarriers?) MAY BE INVOLVED IN THE FACULTATIVE RESPONSES OF THE ENTEROCYTES TO CHANGES IN THE DIETARY LEVELS OF SUGAR AND MAY BE IMPORTANT IN UNDERSTANDING THE INFLUENCES OF DISEASE AND NUTRITIONAL STATUS ON ABSORPTION PROCESSES IN MAN.
Animals↗
Sugar-sensitive thin films composed of concanavalin A and sugar-bearing polymers.
Layered thin films composed of concanavalin A (Con A) and sugar-bearing polymers were prepared by a layer-by-layer deposition of Con A and the polymer on a solid surface. The sugar-induced disintegration was studied. Con A-polymer layered films could be successfully prepared using a maltose-bearing polymer (PV-MA), while melibiose- and glucose-bearing polymers (PV-MEA and PV-G) did not afford a layered film, due to a weak affinity of PV-MEA and PV-G to Con A. The Con A/PV-MA layered film was stable in pH 7 and 8 solutions, while in a pH 6 medium the film was slightly unstable. The Con A/PV-MA film was disintegrated upon the addition of sugars in solution owing to a preferential binding of the sugars to the binding site of Con A in the film. The disintegration rate was dependent on the type of sugar and its concentration. The Con A/PV-MA film was disintegrated rapidly upon the addition of methyl alpha-D-mannopyranoside, while the rate was slower upon the addition of the same concentration of D-mannose, D-glucose and methyl alpha-D-glucopyranoside. The present system may be useful for constructing sensitive devices that can release a drug or other functional molecules in response to sugars.
Carbohydrates↗
[Evaluation of sugar and sugar-containing foods as to their significance for energy and nutrient supply].
There are unique recommendations for an increase in carbohydrates and a reduction of fat in the diets of the western countries and it would be questionable whether sugar could solve partially this problem. There is in fact a significant contribution of carbohydrate energy from sugar. On the other hand it appears uncertain whether this would not lead to a deficit in nutrients for sugar contains only energy but no other nutrients and exhibits in this way a low nutrient density. There are many sweet foods with a high nutrient density, which are highly accepted by the consumers and help to provide people with important nutrients like calcium. Many of them, however, are rich in fat and the most are poor in dietary fiber. If sugar is the main source they are also lacking other nutrients at all. Many problems like the ratio of energy requirement to nutrient demands e.g. in groups with high physical activity are yet not solved. In that way the tolerable sugar content is difficult to calculate for the different groups of the population. For this reason it can not be recommended to increase the sugar consumption above the amount used presently in Germany.
Dietary Carbohydrates↗
Factors associated with the acceptance of sugar and sugar substitutes by the public.
Acceptance is described in both market and sensory research terminology and recent developments in the fields of applied psychology and physiology are examined for their pertinence to public acceptance of sucrose and its substitutes. Information on the function of sucrose in foods other than beverages is presented with emphasis on salivation as an acceptance factor and attention is drawn to its possible dental significance. Distinctions are made between the sweetening and bulking properties of sucrose and sugar substitutes. Factors having a bearing on the acceptance of sweet foods and the determination of their optimal sugar content are described in detail. While major decreases in sucrose intake in the US resulted from high-fructose corn-sweetener usage in soft drinks, no evidence is yet available to suggest that the use of sugar substitutes of the intense artificial sweetener type has caused any decrease in ordinary sugar consumption. Neither is the consumption of polyols (sorbitol, mannitol, xylitol) high enough in confectionery categories to cause any discernible decrease in sugar usage. The evidence suggests not so much that sugar substitutes may have stopped the growth in sucrose usage, but that new product categories such as diet foods and "sugarless' confections may have been created. These categories were never available to fermentable carbohydrate sweeteners and equivalence in acceptance to sucrose-sweetened products was not an important factor in their growth.(ABSTRACT TRUNCATED AT 250 WORDS)
Age Factors↗
Conversion of pyridylamino sugar chains to corresponding reducing sugar chains.
Pyridylamino sugar chains were converted to the corresponding reducing sugar chains by first converting them to 1-amino-1-deoxy derivatives using the method previously reported [S. Hase, J. Biochem. 112, 266-268 (1992)] and then converting the products to the corresponding reducing sugar chains using the Sommlet reaction. The reaction conditions were optimized so as to obtain the maximal product yield using 1-amino-1-deoxylactose and 1-amino-1-deoxy-N-acetylglucosamine. When the established procedure was successively applied to pyridylamino high-mannose and complex-type sugar chains, the corresponding reducing sugar chains were obtained in yields of 30%.
Acetylglucosamine↗
Competition between two pathways for sugar uptake by the phosphoenolpyruvate-dependent sugar phosphotransferase system in Salmonella typhimurium.
The interaction between the two pathways for glucose entry via the phosphoenolpyruvate:sugar phosphotransferase system, i.e. via enzyme II-A/II-B and enzymes II-BGlc/IIIGlc, was studied in Salmonella typhimurium. Thio-beta-D-glucoside and 5-thio-D-glucose were shown to be substrates of P-pyruvate:sugar phosphotransferase specific for enzyme II-BGlc both in intact cells and in toluene-treated cells of S. typhimurium. The activity of the II-A/II-B pathway was strongly inhibited by the presence of II-BGlc substrates. It is concluded that the two pathways compete for phosphoryl groups provided by P-pyruvate, and that under the conditions tested the flow of phosphoryl groups through enzyme I/HPr is the rate-limiting step in vivo of activity of the pathways studied. The results corroborate the proposed mechanism of the regulatory function of the P-pyruvate:sugar phosphotransferase system which predicts a net dephosphorylation of components of the P-pyruvate:sugar phosphotransferase in the presence of a substrate of P-pyruvate:sugar phosphotransferase.
Glucose↗
Determination of nucleotides and sugar nucleotides involved in protein glycosylation by high-performance anion-exchange chromatography: sugar nucleotide contents in cultured insect cells and mammalian cells.
We have developed a simple and highly sensitive HPLC method for determination of cellular levels of sugar nucleotides and related nucleotides in cultured cells. Separation of 9 sugar nucleotides (CMP-Neu5Ac, CMP-Neu5Gc, CMP-KDN, UDP-Gal, UDP-Glc, UDP-GalNAc, UDP-GlcNAc, GDP-Fuc, GDP-Man) and 12 nucleotides (AMP, ADP, ATP, CMP, CDP, CTP, GMP, GDP, GTP, UMP, UDP, and UTP) was examined by reversed-phase HPLC and high-performance anion-exchange chromatography (HPAEC). Although the reversed-phase HPLC, using an ion-pairing reagent, gave a good separation of the 12 nucleotides, it did not separate sufficiently the sugar nucleotides for quantification. On the other hand, the HPAEC method gave an excellent and reproducible separation of all nucleotides and sugar nucleotides with high sensitivity and reproducibility. We applied the HPAEC method to determine the intracellular sugar nucleotide levels of cultured Spodoptera frugiperda (Sf9) and Trichoplusia ni (High Five, BTN-TN-5B1-4) insect cells, and compared them with those in Chinese hamster ovary (CHO-K1) cells. Sf9 and High Five cells showed concentrations of UDP-GlcNAc, UDP-Gal, UDP-Glc, GDP-Fuc, and GDP-Man equal to or higher than those in CHO cells. CMP-Neu5Ac was detected in CHO cells, but it was not detected in Sf9 and High Five cells. In conclusion, the newly developed HPAEC method could provide valuable information necessary for generating sialylated complex-type N-glycans in insect or other cells, either native or genetically manipulated.
Animals↗
Mutants of the lactose carrier of Escherichia coli which show altered sugar recognition plus a severe defect in sugar accumulation.
Lactose and melibiose are actively accumulated by the wild-type Escherichia coli lactose carrier, which is an integral membrane protein energized by the proton motive force. Mutants of the E. coli lactose carrier were isolated by their ability to grow on minimal plates with succinate plus IPTG in the presence of the toxic lactose analog beta-thio-o-nitrophenylgalactoside (TONPG). TONPG-resistant mutants were streaked on melibiose MacConkey indicator plates, and red clones were picked. These melibiose positive mutants were then streaked on lactose MacConkey plates, and white clones were picked. Transport assays indicated that the mutants had altered sugar recognition and a defect in sugar accumulation. The mutants had a poor apparent K(m) for both lactose and melibiose in transport. One mutant had almost no ability to take up lactose, but melibiose downhill transport was 58% (V(max)) of normal. All of the mutants accumulated methyl-alpha-d-galactopyranoside (TMG) to only 8% or less of normal, and two failed to accumulate. Immunoblot analysis of the mutant lactose carrier proteins indicated that loss of sugar transport activity was not due to loss of expression in the membrane. Nucleotide sequencing of the lacY gene from the mutants revealed changes in the following amino acids of the lactose carrier: M23I, W151L, G257D, A295D and G377V. Two of the mutants (G257D and G377V) are novel in that they represent the first amino acids in periplasmic loops to be implicated with changes in sugar recognition. We conclude that the amino acids M23, W151, G257, A295 and G377 of the E. coli lactose carrier play either a direct or an indirect role in sugar recognition and accumulation.
Biological Transport↗
Interactions between soluble sugars and POPC (1-palmitoyl-2-oleoylphosphatidylcholine) during dehydration: vitrification of sugars alters the phase behavior of the phospholipid.
The phase behavior of 1-palmitoyl-2-oleoylphosphatidylcholine (POPC) was characterized as a function of hydration in the presence of combinations of sugars representative of sugars found in seed embryos having differing degrees of desiccation tolerance. The tendency of the sugar mixes to vitrify was also monitored as a function of hydration. Using differential scanning calorimetry, it was found that all sugars diminished the increase in the gel-to-fluid phase transition temperature (Tm) of POPC that occurred upon dehydration of the pure lipid. These results are analyzed in terms of the osmotic and volumetric properties of sugars. Also, it was found that in those samples for which the glass transition temperature (Tg) was greater than the Tm of POPC, Tm was lowered by approx. 20 C degrees from the value for the fully hydrated lipid. X-ray diffraction data confirmed that acyl chain freezing was deferred to a lower temperature during cooling of vitrified samples. The significance of these results is discussed in terms of the ability of many organisms to tolerate desiccation.
Calorimetry, Differential Scanning↗
Antagonism of the morphine-induced locomotor activation of mice by fructose: comparison with other opiates and sugars, and sugar effects on brain morphine.
The mouse locomotor activation test of opiate action in a 2+2 dose parallel line assay was used in a repeated testing paradigm to determine the test, opiate and hexose specificities of a previously reported antagonism of morphine-induced antinocociception by hyperglycemia. In opiate specificity studies, fructose (5 g/kg, i.p.) significantly reduced the potency ratio for morphine and methadone, but not for levorphanol, meperidine or phenazocine when intragroup comparisons were made. In intergroup comparisons, fructose significantly reduced the potencies of levorphanol and phenazocine, but not methadone or meperidine. In hexose/polyol specificity studies, tagatose and fructose significantly reduced the potency ratio for morphine, whereas glucose, galactose, mannose and the polyols, sorbitol and xylitol, caused no significant decrease in potency. Fructose, tagatose, glucose and mannose (5 g/kg, i.p.) were tested for effects on brain morphine levels 30 min after morphine (60 min after sugar), and all four sugars significantly increased brain morphine relative to saline-pretreated controls. It is concluded that the antagonism of morphine by acute sugar administration shows specificity for certain sugars and occurs despite sugar-induced increases in the distribution of morphine to the brain. Furthermore, the effects of fructose show an opiate specificity similar to that of glucose on antinociception observed previously in our laboratory, except that methadone was also significantly inhibited in the present study, when a repeated-testing experimental design was used.
Animals↗
Magnesium-sugar interaction. Synthesis, spectroscopic and structural characterization of Mg-sugar complexes containing beta-D-fructose.
The interaction between beta-D-fructose and hydrated magnesium salts has been studied and complexes of the type Mg(beta-D-fructose)Cl2.4H2O and Mg(beta-D-fructose)Br2.4H2O have been isolated and characterized. On the basis of comparisons of the spectroscopic and other chemical properties of several structurally known calcium-fructose compounds with those of the corresponding magnesium complexes, it is concluded that Mg2+ binds to two sugar moieties via O(2), O(3) of the first and O(4), O(5) of the second and to two water molecules, resulting in a six-coordinate geometry around the Mg2+. The strong sugar hydrogen-bonding network is rearranged upon sugar metallation and the sugar moiety shows the beta-anomer conformation in these magnesium-sugar complexes.
Journal Article↗
Amphetamine-sensitized rats show sugar-induced hyperactivity (cross-sensitization) and sugar hyperphagia.
The goal was to determine the locomotor and consummatory effects of sugar in amphetamine-sensitized rats. Following a 30-min locomotor activity baseline using a photocell cage, male rats were administered either 3.0 mg/kg amphetamine or saline i.p. daily for 6 days. On the final day of injections, locomotor activity was measured again to affirm amphetamine sensitization. Experiment 1: Seven days later, half of each group was offered 10% sucrose or water for 1 min in the home cages, followed by a 30-min locomotor activity test to determine whether or not the animals had become hyperactive in response to sugar. Results showed that amphetamine-sensitized animals were hyperactive following a taste of sugar, but not water. Experiment 2: All subjects were then given access to 10% sucrose for 1 h daily for five consecutive days. Results showed that the amphetamine-sensitized group consumed more sucrose across the 5-day measurement period. These results suggest that sugar may be acting on the same system as amphetamine to trigger hyperactivity, and that alterations in this system caused by repeated doses of amphetamine can instigate an appetite for sugar that persists for at least a week.
Amphetamine↗
Effects of phosphate deficiency and sugars on expression of rab18 in Arabidopsis: hexokinase-dependent and okadaic acid-sensitive transduction of the sugar signal.
The lack of phosphorus in the nutrient medium increased the expression of rab18, an abscisic acid (ABA)-responsive gene, in leaves of Arabidopsis thaliana. The expression of this gene was also upregulated after feeding the excised leaves with D-mannose and sucrose for both wild-type (wt) and aba1 (ABA-deficient) mutant plants. For aba1 mutants, both the phosphate deficiency and sugar effects on rab18 were weaker than in wt plants, suggesting possible involvement of both ABA-dependent and ABA-independent components in signalling. Transgenic Arabidopsis plants with increased hexokinase (HXK) expression had a much higher sucrose-dependent level of rab18 mRNA, implying the HXK involvement in sensing/transmitting the sugar signal. Sucrose-related induction of rab18 was completely inhibited by okadaic acid (OKA), suggesting the involvement of specific protein phosphatase(s) in transduction of the sugar signal. The results suggest that rab18 is regulated via interaction of a plethora of signals, including ABA, sugar and phosphate deficiency, and that the sugar effect is transmitted via a HXK-pathway, involving OKA-sensitive component(s). The findings prompt caution in linking the expression of rab18 solely to ABA signalling.
Abscisic Acid↗