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PubMed1983

Effector cell sensitivity to sugar moieties. II. Inhibition by monosaccharides of interferon enhanced human natural killing.

Little is known at present about the nature of the natural killer (NK) cell-tumor target cell interaction. Human NK cells recognize multiple target antigens. The ligands (antigens) involved in this interaction have not been identified. Previously, we have shown that some monosaccharides inhibit NK cytolysis in a dose-dependent fashion and that NK cell activity involves recognition of carbohydrate structures on target cells via receptors on the effector cell surface. Using human interferon, we have found that monosaccharides inhibit interferon enhanced NK functional activity in a dose-dependent fashion. In addition, we demonstrate that glycosidase treatment of effector cells results in complete inhibition of NK activity.

Adjuvants, Immunologic↗
PubMed1984

Gas chromatographic analysis of lens monosaccharides.

Gas-liquid chromatography was employed to determine free monosaccharides in human, rat, and South American rodent Octodon degu lenses. In addition to D-glucose, D-fructose, sorbitol and myo-inositol, which were previously known to be components of lens tissue, glycerol, erythritol, threitol, ribitol, xylitol, and mannitol were also detected in the lenses of these three species. The concentrations in lenses of these three species were in the following ranges: glycerol 1.2 to 40 mumol/gm wet tissue; myo-inositol 4 to 25; and glucose, fructose, and remaining alditols 0.01 to 1.4/mumol/gm. The method is described and its applicability to analyses of free monosaccharides in other animal tissues is discussed.

Animals↗
PubMed1980

Liquid-chromatographic measurement of urinary monosaccharides.

We describe "high-performance" liquid chromatography of urinary monosaccharides on a macroporous anion-exchange resin (Hitachi 3013N), with acetonitrile/water as eluent. The separated xylose, arabinose, D-fructose, mannose, galactose, and D-glucose were detected by means of a post-column reduction reaction of tetrazolium blue. Absolute limits of detection were about 10 ng of monosaccharide. Lactose can also be measured.

Child↗
PubMed1982

Mechanisms of organic acid and monosaccharide transport in the kidney of the brush-tailed possum, Trichosurus vulpecula.

The mechanisms of organic acid and monosaccharide transport in the kidney of T. vulpecula were investigated using the renal cortical slice preparation. The kinetics, the sensitivity to inhibitors of metabolism and sodium transport, and the specificity of the concentrative uptake of p-amino-hippurate and alpha-methyl-D-glucoside were examined and compared with published results from studies in eutherian mammals. Some minor differences between metatherians and eutherians were noted with regard to the specificities of the renal slice uptake systems. Penicillin G, a competitor of organic acid transport in eutherian kidneys, did not interact with the marsupial uptake system, and sodium acetate, which stimulates transport in other mammals, inhibited p-aminohippurate uptake in the slice of the possum kidney. 2-Deoxy-D-glucose, which interacts with the phlorizin-sensitive monosaccharide transport system in the dog, rat and rabbit kidney, had no effect on alpha-methyl-D-glucoside uptake in the possum, and the magnitude of the interaction of D-fructose resembled that reported in the dog and rat but was greater than the inhibition reported in the rabbit. D-Glucuronic acid and D-glucuronic acid lactone inhibited alpha-methyl-D-glucoside uptake in the possum but had no effect on uptake in rat renal slices. In consideration of the reported variability of these parameters between different classes of eutherians, it was concluded that the primary mechanisms involved in organic solute transport by the proximal nephron of metatherians and eutherians were not significantly different.

Aminohippuric Acids↗
PubMed1978

[Gas-liquid chromatography determination of neutral monosaccharides from a human urine glycopeptide (author's transl)].

Optimum conditions were determined for the satisfactory separation of the carbohydrate residues found in glycoproteins or glycopeptides by using silica gel column chromatography of monosaccharides as their trimethylsilyl ethers. The method is suitable for fractionation of sugar mixtures into neutral sugars and aminosugars. Chromatography on silica and gas-liquid chromatography were used in succession for the rapid determination of the neutral monosaccharides from a human urine glycopeptide.

Chromatography, Gas↗
PubMed1981

IUPAC-IUB Joint Commission on biochemical nomenclature (JCBN). Nomenclature of branched-chain monosaccharides. Recommendations 1980.

The naming of acyclic forms is described, and the first part of this is the rules for choosing which is the parent chain. This leads to naming the parent monosaccharide, including the naming of the C-substituent that forms the branch. Stereochemical conventions have to be extended to specify configuration: the two substituents at one carbon on the parent chain are put in order of priority; that of higher priority is considered to replace hydroxyl and that of lower priority to replace hydrogen in assigning a name to the parent monosaccharide. Equivalent groups and terminal substitution are dealt with separately. Cyclic forms are then described. Many examples are given.

Chemical Phenomena↗
PubMed1978

[Behavior of various blood constituents (glucose, fructose, insulin, lactate, pyruvate, free fatty acids, inorganic phosphate) and half-life of monosaccharides in the plasma after i.v. infusion of glucose, fructose, galactose and invert sugar solutions in ruminants. 1. Studies in calves and heifers].

Studies into the half-life of monosaccharides as well as into the effects of intravenous infusion of sugar solutions (0.5 g/kg body weight of glucose, fructose, galactose, and invert sugar) on the concentration of various blood components were undertaken with six calves and five heads of young cattle. Half-life values of glucose and galactose were of nearly identical magnitude over the first weeks of age, whereas that of fructose was much longer on account of slower conversion. Infusion of invert sugar solution, therefore, cannot be recommended for calves during the first three weeks of age. Infusion of the above monosaccharides led to more or less strongly pronounced rise of insulin levels in the blood serum. More or less strongly marked pyruvate increase took place following infusion, if the pyruvate concentration in the blood plasma had been low before infusion. Lactate levels in the blood usually underwent little change, whereas the levels of free fatty acids and inorganic phosphate in the blood plasma usually were reduced.

Animals↗
PubMedDate not supplied

Possible monosaccharide composition of glycopolymers located on the external side of membranes of cells of some mollicutes.

Monosaccharide composition of glycopolymers of five mollicutes (Mycoplasma pneumoniae FH, M. hominis PG 21, M. fermentans PG 18, Acholeplasma laidlawii PG 8 and A. laidlawii var. granulum 118) integrated with their membrane has been studied by means of nine plant lectins with certain carbohydrate specificity labelled with colloid gold. Monosaccharide composition of glycopolymers depends both on the mollicute species and on its capacity to evoke diseases in different microorganisms. Thus genetically relative A. laidlawii PG 8 (saprophytic microorganism) and A. laidlawii var. granulum 118 (an agent of pale-green dwarfness of cereals) have the ratio between N-acetyl-D. galactosamine and N-acetyl-D-glucosamine 2:1 and 1:2, respectively. Large amounts of such exotic sugar as L-fucose have been found in M. hominis PG 21, M. fermentans PG 18 and A. laidlawii PG 8. L-fucose plays the basic role in disguising cells of these mollicutes in human organism (as O(H)-group blood erythrocytes), which permits these mollicutes disseminating through the whole organism. The composition of extracellular glycopolymers of mollicutes is discussed to reveal their role in the processes of adhesion and specialization (organotropism) of these microorganisms in populating the corresponding organs and tissues of macroorganisms.

Cell Membrane↗
PubMed1976

Role of monosaccharides in the interaction of two lymphocyte mediators with their target cells.

The role of monosaccharides on the interaction of two lymphocyte mediators related to the human cell migration inhibition systems with their respective target cells has been investigated. Human MIF activity on blood monocytes was significantly reduced by several 5-methylpentose sugars indcluding L-fucose, L-rhamnose and 6 deoxy-D-glucose. Certain structurally unrelated monosaccharides such as D-galactose, methyl alpha-D-mannoside and N-acetyl-D-glucosamine had no effect on this system. Incubation of human monocytes with alpha-L-fucosidase, a glycosidase which cleaves terminal L-fucose moieties, reversibly prevented their response to MIF. These results indicate that alpha-L-fucosyl residues form an integral part of the receptor for MIF on human monocytes, and furthermore, this interaction may be somewhat nonspecific in that the 5-methylpentose configuration perse is recognized. In contrast, human LIF activity on PMN leukocytes was significantly reduced by N-acetyl-D-galactosamine, but not by 5-methylpentoses, D-glucose, N-acetyl-D-galactosamine, methyl alpha-Dmannoside or D-galactose. The latter finding suggests that a subterminal sugar may form part of the receptor to LIF on human PMN leukocytes.

Acetylglucosamine↗
PubMed2006

Hexose-specificity of hexokinase and ADP-dependence of pyruvate kinase play important roles in the control of monosaccharide utilization in freshly diluted boar spermatozoa.

Incubation of boar sperm from fresh ejaculates in a minimal medium with 10 mM glucose induced a fast and intense activation of glycolysis, as indicated by the observed increases in the intracellular levels of glucose 6-phosphate (G 6-P) and ATP and the rate of formation of extracellular L-lactate. The effect of glucose was much more intense than that induced by fructose, sorbitol, and mannose. The greater utilization of glucose was related to a much greater sensitivity to hexokinase when compared with the other monosaccharides. Thus, the presence of 0.5 mM glucose induced total hexokinase activity in supernatants from sperm extracts of 1.7 +/- 0.1 mIU/mg protein, while the same concentration of both fructose, mannose, and sorbitol induced total hexokinase activity from 0.3 +/- 0.1 mIU/mg protein to 0.60 +/- 1 mIU/mg protein. Kinetic analysis of the total pyruvate kinase activity indicated that this activity was greatly dependent on the presence of ADP and also showed a great affinity for PEP, with an estimated Km in supernatants of 0.15-0.20 mM. Immunological location of proteins closely related to glycolysis, like GLUT-3 hexose transporter and hexokinase-I, indicated that these proteins showed the trend to be distributed around or in the cellular membranes of both head and midpiece in a grouped manner. We conclude that glycolysis is regulated by both the specific availability of a concrete sugar and the internal equilibrium between ATP and ADP levels. Furthermore, localization of proteins involved in the control of monosaccharide uptake and phosphorylation suggests that glycolysis starts at concrete points in the boar-sperm surface.

Adenosine Diphosphate↗
PubMed2002

Advancing monosaccharides as biomarkers: part I. Development of fluorophore-assisted carbohydrate-electrophoresis in Chironomus riparius.

Fluorophore-assisted carbohydrate-electrophoresis (FACE) was developed as a bioassay for environmental stressors in larval Chironomus riparius. This quantitative technique involved acid hydrolysis and 2-aminoacridone labeling of monosaccharides followed by carbohydrate gel electrophoresis. Methods for carbohydrate isolation from whole tissue homogenates as well as migration distances for 23 different monosaccharides and 4 disaccharides were established. Sensitivity of the technique (5 microg/ml saccharide) exceeded those of other detection methods. Results showed seven distinct bands in larvae. Four migrated distances similar to those of ribose, glucose, galactose, and fructose. Three proved to be alternative reaction products (ARP). Experiments determined that two of the ARPs were primarily from glucose and one was from glycogen. FACE allowed different saccharides from multiple larval samples to be analyzed in parallel. Effects of toxicants and diet on bioenergetics could be studied using this technique.

Aminoacridines↗
PubMed1978

Intestinal transport of monosaccharide after biliary diversion in the rat.

Sugar absorption is increased in rats with a bile fistula but approaches normal values with the addition of bile salt. It has therefore been suggested that bile salts have a physiological role in decreasing intestinal absorption of monosaccharides. In experiments using rats, jejunal and ileal uptake of arbutin, a glucose analogue was increased 5 days after creating a bile fistula but normal by the 10th day after operation. Bile fistula rats ate only about one third of the intake of normal rats in the first 5 days after operation. Control animals fed the same amount as the bile fistula group showed a similar increase in jejunal and ileal arbutin uptake. In both groups, on the 5th post-operative day, addition of taurocholate depressed arbutin uptake towards normal. In normal rats, taurocholate depressed arbutin uptake in the ileum but not the jejunum. These results suggest that increased monosaccharide uptake in bile fistula rats is related to semi-starvation and is not a specific effect of bile salts.

Animals↗
PubMed1991

The hydrolysis of lucerne cell-wall monosaccharide components by monocultures or pair combinations of defined ruminal bacteria.

The defined ruminal bacterial strains Fibrobacter succinogenes S85, Ruminococcus flavefaciens FD1, Ruminococcus albus 7, Butyrivibrio fibrisolvens D1, and Bacteroides ruminicola GA33 were grown, in monocultures or as combinations of pair strains, on isolated lucerne cell-walls (CW) as the sole carbohydrate substrate. Fibrobacter succinogenes S85 was the dominant strain determining extent of CW hydrolysis in all combinations with S85. The hydrolysis of cellulose, xylan, hemicellulose side-sugars, and total CW monosaccharides by pure S85 were: 58.8, 47.3, 66.9 and 57.0%, respectively. The strains combination S85 plus D1 comprised the highest complementary effect, increasing significantly the hydrolysis of cellulose and total CW monosaccharides by 16% and 13%, respectively, above the values obtained by pure S85. This complementation was expressed also in growth pattern of bacteria. The monocultures of FD1, D1 and GA33 had very little hydrolytic effect on lucerne cellulose, but higher effects on xylan and hemicellulose side-sugars. The combinations D1 plus GA33 and 7 plus GA33 were complementary in the hydrolysis of all CW polysaccharides. The combinations FD1 plus D1, FD1 plus GA33, and 7 plus D1 were complementary only with respect to hemicellulose hydrolysis. On the other hand, the cellulolytic combinations S85 plus FD1, S85 plus 7 and FD1 plus 7 demonstrated negative interactions in lucerne CW polysaccharides hydrolysis. Under scanning electron microscopy (SEM), S85 comprised the most dense layer of bacterial cell mass attached to and colonized on CW particles. The cell surface topology of the cellulolytic strains S85, FD1 and 7 attached to CW particles was specified by a coat of characteristic protuberant structures.

Animals↗
PubMed1979

A kinetic study of the interactions between amino acids and monosaccharides at the intestinal brush-border membrane.

1. The influx of amino acids into guinea-pig intestinal rings in vitro is inhibited by monosaccharides, and that of monosaccharides by amino acids. Two hypotheses have been proposed to account for these heterologous interactions. According to the first, the cis hypothesis, there is an allosteric interaction between substrates binding to separate but related sites at the outer face of the brush-border membrane matrix. In contrast, the trans hypothesis envisages the interaction to result from a partial dissipation of the electrochemical sodium gradient due to the cotransport of each substrate with sodium ions. 2. In an attempt to distinguish between the merits of the two hypotheses, we examined the kinetics of the inhibition of phenylalanine influx by two sugars of widely different affinities, galactose and beta-methylglucoside. Since beta-methylglucoside carries more sodium into the cell than galactose, the trans hypothesis would predict it to be the stronger inhibitor, but in fact the opposite result is found. 3. Equations were developed to describe the inhibitions in accordance with the cis hypothesis. The satisfactory agreement between experimental observations and theoretical predictions provides support for the applicability of the model. Further implications of the polyfunctional carrier model are discussed.

Allosteric Regulation↗
PubMed1984

Hamster intestinal disaccharide absorption: extracellular hydrolysis precedes transport of the monosaccharide products.

Hydrolase-related transport was re-investigated in hamster small intestine by the tissue accumulation method. The Na+-dependent, phlorizin-sensitive monosaccharide transport system saturates with 30 mM-D-glucose. According to the hydrolase-related transport hypothesis, additional glucose units will be taken up if they are given in the form of a disaccharide susceptible to hydrolysis. But in experiments with [14C]sucrose we found no evidence for any such surplus glucose uptake. The uptake of 14C label from sucrose was abolished by using Tris, a strong inhibitor of sucrase, by adding competitive inhibitors of the D-glucose transport system (D-glucose, beta-methyl-D-glucopyranoside or phlorizin), and by substituting Li+ for the Na+ in the incubation medium. Glucose and fructose derived from sucrose did not enter the tissues in equimolar amounts: the glucose moiety was taken up much faster. We conclude that in hamster intestine there is no evidence for the existence of hydrolase-related transport with sucrose as the monosaccharide donor. The enzymatic hydrolysis of sucrose and the transport of its products, glucose and fructose, are two distinct events, acting sequentially.

Animals↗
PubMed1995

Expression of endotoxic activities by synthetic monosaccharide lipid A analogs with alkyl-branched acyl substituents.

Synthetic monosaccharide lipid A analogs with alkyl-branched acyl substituents instead of the usual ester-branched acyl substituents were investigated for their biological activities. The activities were compared with those of a representative synthetic monosaccharide lipid A analog with an ester branch (GLA-60) and synthetic complete lipid A (506) to estimate the role of the attaching mode of the branched side chains for expression of endotoxic activities. Among the analogs with alkyl branches, GLA-146 and GLA-147, which have C12 and C14 alkyl side chains, respectively, showed strong endotoxic activities. These analogs exhibited comparable or stronger activities than those of GLA-60 in murine macrophage activation activities to induce mediators such as tumor necrosis factors, interleukin 6, and nitric oxide and in mitogenic activity towards murine spleen cells; however, these activities were weaker than the respective activities of 506. With respect to lethal toxicity to galactosamine-sensitized mice, the analogs showed stronger activity than that of GLA-60 and activity closer to that of 506. With respect to adjuvant activity, no significant activity was observed in the analogs, while the activities of GLA-60 and 506 were strong. When lipopolysaccharide-resistant C3H/HeJ mice were used, the activities described above were not observed either for the analogs under investigation nor for GLA-60 and 506. These findings indicate that the ester type of branch in lipid A and its analogs does not play an indispensable role in the expression of various endotoxic activities. However, it may play some role in the expression of adjuvant activity and in lowering the level of toxicity.

Adjuvants, Immunologic↗
PubMed1998

Relationship of structure and biological activity of monosaccharide lipid A analogues to induction of nitric oxide production by murine macrophage RAW264.7 cells.

Lipid A is the active center of bacterial lipopolysaccharide (LPS), which exhibits diverse biological activities via the production of various mediators. We investigated the production of nitric oxide (NO), one of the mediators, by a murine macrophage cell line, RAW264. 7, upon stimulation with a series of monosaccharide lipid A analogues to elucidate the relationship of structure and activity in NO production. The production of other representative mediators, such as tumor necrosis factor alpha (TNF-alpha) and interleukin-6 (IL-6), was also investigated to compare the structural requirements for the production of these cytokines with those for the production of NO. Structure-activity relationships in NO production correlated well with those in the production of TNF-alpha and IL-6. Among the lipid A analogues possessing different numbers of acyl groups on a 4-O-phosphono-D-glucosamine backbone, compounds like GLA-60 that possess three tetradecanoyl (C14) groups exhibited stronger activities in the production of the mediators than compounds possessing four or two C14 groups. Time course study of the production of these mediators showed that production of NO started and peaked later than those of TNF-alpha and IL-6. Neither neutralization of TNF-alpha activity by antibody nor suppression of TNF-alpha production by pentoxifylline showed a significant suppressive effect on production of NO and IL-6 upon stimulation with LPS or lipid A analogues. Neutralization of IL-6 activity by antibody showed no significant suppressive effect on production of NO and TNF-alpha. A monosaccharide lipid A analogue (GLA-58) which exhibited no detectable agonistic activity showed a suppressive effect on the production of all three mediators upon stimulation with LPS or lipid A analogues. These results indicate that signals for NO production by LPS agonists in murine macrophages are transduced in good correlation with those for production of TNF-alpha and IL-6, although they are not transduced via production of those cytokines.

Acylation↗
PubMed1999

Activity of monosaccharide lipid A analogues in human monocytic cells as agonists or antagonists of bacterial lipopolysaccharide.

The lipid A portion of bacterial lipopolysaccharide (LPS) plays a central role in the production of endotoxic mediators. Different responses between human and murine macrophages to lipid A-like structures have been indicated. We investigated a series of structurally related monosaccharide lipid A analogues for their potency to activate human macrophage U937 cells and peripheral blood mononuclear cells for production of tumor necrosis factor-alpha and interleukin-6 compared with their potency to activate murine macrophage RAW264.7 cells. Two of the analogues were found to have sufficient potency to activate the human cells as well as the murine cells. These analogues comprise D-glucosamine, phosphoryl groups, and acyl groups of defined carbon chain lengths (C(14) and C(12)) in a ratio of 1:1:3. This ratio of molecular constituents is proportional to that of the complete disaccharide structure of lipid A (2:2:6). Other analogues with two or four C(14) acyl groups and with three acyl groups but including a C(10) or a C(16) acyl group, which are active to murine cells, showed no LPS-agonistic activity, but did show LPS-antagonistic activity, to human cells. An LPS-antagonistic analogue in the murine cells also showed antagonistic activity in human cells. These results reveal that lipid A analogues recognized as being LPS agonists by human macrophages have common structural features in monosaccharide and disaccharide structures which are more strict than those required for recognition by murine macrophages and that broad lipid A-like structures are recognized as being LPS antagonists by human cells but are recognized by murine cells as being either LPS agonists or antagonists.

Animals↗