SEARCH · PubMed Health

Results for “Fructans”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 559 records · Page 31Linked to original sources

PubMed1983

Idiotype-antiidiotype regulation. IV. Expression of common regulatory idiotopes on fructosan-binding and non-fructosan-binding monoclonal immunoglobulin.

The ABPC-48 Id (A48 Id) is normally not expressed in detectable amounts in the serum of BALB/c mice that have been immunized with bacterial levan (BL). However, A48 Id-bearing anti-BL clones can be activated in BL-immunized mice by three distinct prior treatments: (a) administration of A48 Id-bearing monoclonal proteins to newborn mice; (b) administration of minute amounts of anti-Id antibodies to newborn mice; and (c) production of anti-(anti-A48 Id) antibodies (Ab3), in adult mice. From these three groups of mice, eighteen monoclonal antibodies (MAb) expressing A48 Id were obtained. Regarding the binding specificity, these MAb can be divided into three groups: one that binds only BL, the second that binds BL and displays low cross-reactivity for inulin, and the third that lacks BL- and inulin-binding activity. This latter group was obtained only from adult mice immunized with anti-A48 Id-KLH conjugate. Immuno-chemical analysis of these MAb has shown that the A48 Id is made up of several idiotopes, some of them associated with the combining site and others nonantigen inhibitable. Comparisons of the amino acid sequence of the UPC-10 and A48 VH regions, and the distribution of the A48 Id family on A48, UPC-10, and three MAb, suggested that A48 regulatory idiotypes can be located on the framework segment of VH region. Furthermore, we screened 198 mouse and 80 human myeloma proteins for their ability to express A48 Id. Of these, only MOPC-167, an IgAk phosphocholine (PC)-binding myeloma protein, gave a significant inhibition of binding of labeled A48 to anti-A48 Id antibodies by radioimmunoassay and enzyme-linked immunosorbent assay. In addition, the binding of labeled MOPC-167 to anti-A48 Id antibodies was not inhibited by PC but was inhibited by A48 and 3-76-42 MAb bearing A48, UPC-10 non-antigen-inhibitable idiotopes. These results extend our prediction that the regulatory idiotopes can be expressed not only on antibodies specific for a family of antigens or members of the same network pathway, but also can be shared by antibodies with different antigenic specificity.

Animals↗

PubMed1983

ABPC 48 cross-reactive idiotopes in BALB/c mice. Natural and levan-induced expression.

Using monoclonal antiidiotypic antibodies, we developed a sensitive binding assay that detects molecules with one or with two idiotopes of the ABPC48 idiotype. ABPC48 cross-reactive idiotypes were thus shown to be present in substantial amounts in sera of nonimmunized mice. Levan binding sites are found on these idiotypes. During the life time of the mice, the natural anti-levan titer increases while ABPC48 idiotypic expression remains constant, suggesting different controls for these two activities. On the other hand, ABPC48 cross-reactive idiotypes participate--as minor components--in the response that follows a deliberate immunization with bacterial levan. This induction process is likely to reflect the selection of idiotopes expressed by the B cell clones preactivated in sera of nonimmunized mice rather than the activation of silent clones. We suggest that a similar situation might explain the reported emergence of ABPC48 idiotypes in animals primed with antiidiotypic antibodies and subsequently stimulated with levan.

Animals↗

PubMed1983

Idiotype-antiidiotype regulation. V. The requirement for immunization with antigen or monoclonal antiidiotypic antibodies for the activation of beta 2 leads to 6 and beta 2 leads to 1 polyfructosan-reactive clones in BALB/c mice treated at birth with minute amounts of anti-A48 idiotype antibodies.

The anti-beta 2 leads to 6 fructosan antibodies sharing the idiotypes (Id) of ABPC48 (A48) monoclonal protein represent a silent fraction of the anti-beta 2 leads to 6 fructosan repertoire, since these antibodies cannot be detected during a conventional immune response elicited by bacterial levan (BL). However, the administration at birth of minute amounts of anti-A48 Id antibodies causes a long-lasting activation of A48 Id+-bearing clones. This activation is related to direct interaction of anti-A48 Id antibodies with precursors bearing the A48 Id+ immunoglobulin receptor, since an A48 Id+ response can be transferred with highly purified B cells in lethally irradiated mice. The maturation of these precursors into A48 Id+ anti-beta 2 leads to 6 fructosan antibody-secreting cells requires challenge by the antigen. Isoelectric focusing (IEF) data showed that in 1-mo-old mice an UPC10 (U10)-like spectrotype was observed, whereas in 3-mo-old mice, a new spectrotype binding BL rather than inulin (In) was identified. This spectrotype was observed only in CXBJ mice, the single strain in which an A48 Id+ response was observed. The antigenic challenge can be replaced by a monoclonal anti-A48 Id antibody (i.e., 17-38). Interestingly, in 1-mo-old BALB/c mice treated with anti-A48 Id antibodies, the challenge with 17-38 monoclonal antibody led to the activation of A48 Id- anti-beta 2 leads to 6 fructosan-reactive clones with BALB/c type IEF spectrotypes, whereas in 3-mo-old BALB/c mice treated with anti-A48 Id antibodies, the challenge with 17-38 monoclonal antibody led to the activation of W3082 IdX+ anti-beta 2 leads to 6 and beta 2 leads to 1 fructosan-reactive clones. In these animals, inhibition of A48 Id+ anti-beta 2 leads to 6 fructosan clones was observed. This antibody probably represents a homobody carrying the internal image of the antigen, which through its paratope suppresses the A48 Id+ response and through its Id activates an A48 Id- anti-beta 2 leads to 6 fructosan response in 1-mo-old mice and in 3-mo-old mice leads to an anti-beta 2 leads to 6 and beta 2 leads to 1 fructosan response dominated by the W3082 IdX.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗

PubMed1985

Immunochemical and molecular characterization of regulatory idiotopes expressed by monoclonal antibodies exhibiting or lacking beta 2-6 fructosan binding activity.

Hybridomas secreting antibodies bearing the ABPC48 (A48) regulatory idiotype (Id) were generated from BALB/c mice treated at birth or as adults with minute amounts of anti-A48-Id antibodies. The majority of these antibodies were recognized by the syngeneic monoclonal anti-A48-Id and anti-UPC-10-Id antibodies, IDA10 and 10-1, respectively. In Northern blotting experiments, most of these hybridomas were shown to use VH (heavy chain variable region) genes related to the 441-4 germline VH gene that encodes the A48 VH region. Hybridization was detected between polyadenylated H chain mRNA, isolated from the majority of the hybridomas, and the VH probe. Southern blots confirmed these results by showing a rearrangement of VH-related sequences to the JH (H chain joining segment) clusters on these same hybridomas. The antibodies from all of the hybridomas that derived from neonatal mice and half of those derived from adult mice showed specificity for fructosan determinants that, in most cases, was different from the beta 2-6 fructosan linkage specificity of A48. Surprisingly, several of the non-fructosan-binding hybridomas generated from the adult mice and the MOPC-173 myeloma demonstrated a clear specificity for the beta 1-6-D-galactan determinant. Of four galactan-binding myeloma proteins studied. XRPC 44 alone shared idiotypy with the UPC-10 myeloma. These findings suggest a possible clonal crossreactive regulation mediated by regulatory idiotopes. The crossreactive regulation concept is discussed.

Animals↗

PubMed1951

Studies on non-hemolytic streptococci isolated from the respiratory tract of man; the antigenic basis for type specific reactions with streptococcus salivarius and non-levan-forming streptococci.

The type specific immunological properties of certain non-hemolytic streptococci, including Str. salivarius type I and type II, present in the respiratory tract of human beings appear to be dependent upon the presence of capsular polysaccharides. The levans formed from sucrose by Str. salivarius (encapsulated S cells or non-encapsulated R variants), or by cell-free enzymes derived from these microorganisms, are indistinguishable immunologically and show no evidence of type specificity. Such levans appear to be immunologically distinct from and unrelated to the capsular polysaccharides of the microorganisms which produce them.

Fructans↗

PubMed2006

Reducing shock number dramatically decreases lesion size in a juvenile kidney model.

BACKGROUND AND PURPOSE: Adult stone patients are treated with several thousand lithotripter shockwaves (SWs) in order to pulverize a kidney stone. This typical clinical dose assures that the stone will be fractured completely. However, this same dose induces damage to the kidney, especially pediatric-size kidneys. If increasing SW number is known to increase renal injury and functional impairment, will reducing SW number below typical treatment levels significantly decrease kidney damage and hemodynamic changes? MATERIALS AND METHODS: To address this question, one kidney in each of nine juvenile pigs (6-7 weeks old) was treated with 1000 SWs at 24 kV directed at a lower-pole calix with an unmodified HM-3 lithotripter. Parenchymal-lesion size was determined by sectioning the entire kidney and quantitating the amount of hemorrhage in each slice. Renal function was determined before and after SW treatment by inulin clearance, paraaminohippurate (PAH) extraction, and PAH clearance. The resulting morphologic and functional changes were then compared with those of kidneys that had been treated with a typical clinical dose of 2000 SWs (data previously published; J Am Soc Nephrol 2000;11:310). Eleven pigs were utilized as sham-treated controls. RESULTS: Limiting SW number to 1000 significantly reduced the size of the lesion (by 95%) and reduced the degree of functional change (glomerular filtration rate by 38%, PAH extraction by 73%, renal plasma flow by 46%) compared with kidneys receiving 2000 SWs (an adult dose). CONCLUSIONS: These data support the idea that SW number should be reduced to the lowest number that fractures kidney stones in order to minimize renal injury and functional impairment.

Animals↗

PubMed2001

An artificial sweetener stimulates the sweet taste in insect: dual effects of glycyrrhizin in Phormia regina.

Glycyrrhizin, found in the root of licorice (Glycyrrhizia glabra), has been used extensively as a non-sugar sweetener for humans and also as a medicine. As far as we know, the present work is the first report describing that a non-sugar sweetener for humans induces a sweet taste in insects. In behavioural experiments, we found that glycyrrhizin induced the feeding response, including full proboscis extension in the blowfly, Phormia regina. Glycyrrhizin also induced impulses of the sugar receptor cell in the labellar chemosensillum, which is highly specialized for the tastes of sugars and nucleotides. The optimum concentration of glycyrrhizin was 3.0 mM, which is much lower than that of sucrose. It has been established that multiple receptor sites, the pyranose receptor site (P site) and the furanose receptor site (F site), are present in the sugar receptor cell of the blowfly and the fleshfly. The inhibitors specific to the P site, starch and PCMB (p-chloromercuribenzoate), partially inhibited glycyrrhizin-induced responses but not levan (an inhibitor to the F site), indicating that the P site on the sugar receptor cell is involved in the glycyrrhizin action but not the F site. When 30 s stimulation with 3.0 mM glycyrrhizin was repeated with an interval of 3--10 min, the impulse frequency to the second stimulus was higher than that to the first one and doubled within 6 min. The first stimulus lasting longer than 10 s potentiated the impulse generation and reduced the adaptation rate during the second stimulus. These results suggest that, in addition to the action via the P site, an additional mechanism, possibly in the signal transduction cascade of the sugar receptor cell, may be involved in the action of glycyrrhizin.

Adaptation, Physiological↗

PubMed1999

Oligo-L-methionine and resistant protein promote cecal butyrate production in rats fed resistant starch and fructooligosaccharide.

We examined the role of resistant protein and peptides in promoting cecal butyrate production in rats fed rapidly fermentable carbohydrates. Rats were fed diets containing raw potato starch (RPS, 200 g/kg diet) or fructooligosaccharide (FOS, 60 g/kg diet) with casein, soy or rice protein (250 g/kg diet) for 13 d. In rats fed RPS with casein, the major cecal organic acid was acetate (441 micromol), but lactate and succinate were also found in considerable amounts (324 micromol). Succinate was the major cecal organic acid (235 micromol) in rats fed FOS with casein. When rice protein was fed with RPS, the contribution of lactate was significantly lower and that of propionate tended to be higher (P < 0.1) than in rats fed casein. In rats fed rice protein with FOS, cecal butyrate and acetate were greater and cecal succinate was lower than in rats fed casein with FOS (P < 0.05). Despite the similar amounts of undigested protein in rice and soy proteins, soy protein did not similarly affect cecal butyrate in rats fed FOS or RPS. In another experiment, rats were fed diets containing high amylose cornstarch (HAS, 200 g/kg diet) with casein, casein + oligo-L-methionine (OM, 3 g/kg diet), soy protein, soy protein + OM (3 g/kg diet) or rice protein (250 g/kg diet) for 10 d. OM (digestibility, 31%) was substituted for the same amount of casein. Rats fed rice protein had greater cecal butyrate than rats fed casein (P < 0.05). OM supplementation to casein or soy protein increased cecal butyrate compared with rats fed casein or soy protein alone (P < 0.05). These data support our hypothesis that resistant protein and peptides promote cecal butyrate production and suggest that the differing potency of rice and soy proteins in promoting cecal butyrate production might be explained in part by the different amino acid composition of resistant protein.

Analysis of Variance↗

PubMed1979

Synthesis of levan by levansucrase. Some factors affecting the rate of synthesis and degree of polymerization of levan.

The addition of levan as a so-called "acceptor" accelerated the rate of polymerization of levan catalyzed by levansucrase [EC 2.4.1.10]. However, this effect was seen only under conditions of low ionic strength. Under conditions of high ionic strength, only levan with an average degree of polymerization (DP) of 120 was synthesized with a reasonable yield. Incorporation of [14C]fructose residues into levan of high molecular weight (DP 1,200) added as an "acceptor" at high ionic strength was slight. It is suggested that the DP of levan synthesized is generally regulated by ionic strength, and that enzymic synthesis of levan occurs in the absence of an "acceptor."

Bacillus subtilis↗

PubMed1980

The molecular structure of low and high molecular weight levans synthesized by levansucrase.

The levan synthesized by Bacillus subtilis levansucrase in the presence of alcohols was of only high molecular weight, while in solutions of high ionic strength only low molecular weight (MW) levan was produced. The addition of low MW levan to the enzyme reaction mixture at low ionic strength stimulated synthesis of a high MW levan, but the levan added was not incorporated into this high MW levan. Methylation analysis revealed that low MW levans contained glucose, which was isolated as 2,3,46-tetra-O-methyl alditol acetate showing that the glucose units existed as terminal residues. The molecular weight of levan estimated on the basis of glucose content coincided with that determined by the gel filtration method. Methylation analysis also revealed that the number of fructose residues of the linear fraction linked by leads to 6(F)2 leads to type bonds was 22 for levan with a molecular weight of (8.4(-22)) x 10(3), while it was 11 for that of 2,000 x 10(3). The number of (formula: see text) type branched residues increased with increase in the molecular weight of the levan synthesized.

Bacillus subtilis↗

PubMed1981

Structures of heterooligosaccharides synthesized by levansucrase.

In the presence of excess amounts of various monosaccharides as acceptors, Bacillus subtilis levansucrase synthesized various heterooligosaccharides as a result of transfer of the fructosyl residue from sucrose. The saccharides produced in the presence of D-glucose, D-mannose, and D-xylose were all non-reducing disaccharides and were identified as beta-D-fructofuranosyl-alpha-D-glucopyranoside (sucrose), beta-D-fructo-furanosyl-alpha-D-mannopyranoside (mannosucrose), and beta-D-fructofuranosyl-alpha-D-xylopyranoside (xylsucrose), respectively. The saccharides produced in the presence of D-galactose were also non-reducing, but consisted of di-, tri-, and tetrasaccharides. The di- and trisaccharides were galsucrose and 6F-beta-D-fructofuranosyl-galsucrose. The saccharide synthesized in the presence of L-arabinose was a reducing saccharide and was determined to be 4-O-beta-D-fructofuranosyl-L-arabinose. In the presence of D-fructose, several reducing levan oligomers, levanbiose, levantriose, levantetraose, etc., were produced, which were not observed in the synthesis of levan from sucrose alone.

Arabinose↗

PubMed1981

Enzymic formation of difructose anhydride IV from bacterial levan.

A novel enzyme for producing difructose anhydride IV (di-D-fructofuranose 2,6' : 6,2' dianhydride) from levan of Bacillus mesentericus was prepared from a culture of Arthrobacter ureafaciens, and the conditions and method to determine the enzymatic activity were determined. Levan of Bacillus subtilis also yielded the difructose dianhydride, but inulin, inulobiose, sucrose, levanbiose, and levantriose did not produce it on enzymic reaction under similar test conditions.

Arthrobacter↗

PubMed1980

Bacterial meningitis complicated by spinal arachnoiditis: diagnostic contribution of Tc-99m-inulin myeloscintigraphy.

Six cases of bacterial meningitis with myeloscintigraphic evidence of medullary arachnoiditis are reported. Four patients has tuberculous meningitis, another showed severe myelopathy, and the last was suspected to have hydrocephalus. Arachnoiditis is suspected when the earliest images show a sharp decrease of tracer concentration. Scintigraphy began 2 hours after lumbar injection of Tc-99m-Polyfructosan and imaging was performed at intervals of 2, 4, and 6 hours. This method has proved easy, innoculous, reproducible, and, owing to the small amount of irradiation, studies may be repeated during and after therapy. Scintigraphy is superior to the Queckenstedt test becaise it detects partial blocks and localizes lesions.

Adolescent↗

PubMed1990

Effects of intravenous immunoglobulin on hemorrhage-induced alterations in plasma cell repertoires.

Hemorrhage produces decreases in serum immunoglobulin (Ig) levels and alterations in the number and frequency of B cells producing antibodies against bacterial antigens. These abnormalities in immune response may contribute to the increased susceptibility to infection after injury and hemorrhage. To examine the relationship between serum Ig levels and bacterial antigen-specific plasma cell numbers and frequencies after blood loss, we treated hemorrhaged mice with intravenous Ig (IVIG). Hemorrhaged mice given IVIG had increased total numbers of splenic plasma cells compared with normal or hemorrhaged, untreated mice. Immunization with the bacterial polysaccharide antigen levan immediately after hemorrhage resulted in approximately 60% fewer levan-specific splenic plasma cells than those seen in normal unhemorrhaged mice. Treatment of hemorrhaged mice with IVIG did not correct the decrease in levan-specific plasma cells. These results demonstrate that hemorrhage-induced alterations in the numbers and frequencies of bacterial antigen-specific B cells are not related to changes in serum Ig levels and cannot be corrected through administration of IVIG.

Animals↗

PubMed2004

Autogenous modulation of the Bacillus subtilis sacB-levB-yveA levansucrase operon by the levB transcript.

Silencing of levB, the second structural gene of the tricistronic levansucrase operon encoding the endolevanase LevB, decreases the level of levansucrase expression in Bacillus subtilis. Conversely, independent expression of levB greatly stimulates operon expression. This autogenous effect is mediated by the levB transcript, which carries an internal sequence (5'-AAAGCAGGCAA-3') involved in the enhancing effect. In vitro, the levB transcript displays an affinity for the N-terminal fragment of SacY (K(D) 0.2 microM), the regulatory protein that prevents transcription termination of the levansucrase operon. This positive-feedback loop leads to an increase in the operon expression when B. subtilis is growing in the presence of high sucrose concentrations. Under these conditions, extracellular levan synthesized by the fructosyl polymerase activity of levansucrase can be degraded mainly into levanbiose by the action of LevB. Levanbiose is neither taken up nor metabolized by the bacteria. This work modifies the present view of the status of levansucrase in B. subtilis physiology.

Amino Acid Transport Systems, Acidic↗

PubMed2006

Contribution of alginate and levan production to biofilm formation by Pseudomonas syringae.

Exopolysaccharides (EPSs) play important roles in the attachment of bacterial cells to a surface and/or in building and maintaining the three-dimensional, complex structure of bacterial biofilms. To elucidate the spatial distribution and function of the EPSs levan and alginate during biofilm formation, biofilms of Pseudomonas syringae strains with different EPS patterns were compared. The mucoid strain PG4180.muc, which produces levan and alginate, and its levan- and/or alginate-deficient derivatives all formed biofilms in the wells of microtitre plates and in flow chambers. Confocal laser scanning microscopy with fluorescently labelled lectins was applied to investigate the spatial distribution of levan and an additional as yet unknown EPS in flow-chamber biofilms. Concanavalin A (ConA) bound specifically to levan and accumulated in cell-depleted voids in the centres of microcolonies and in blebs. No binding of ConA was observed in biofilms of the levan-deficient mutants or in wild-type biofilms grown in the absence of sucrose as confirmed by an enzyme-linked lectin-sorbent assay using peroxidase-linked ConA. Time-course studies revealed that expression of the levan-forming enzyme, levansucrase, occurred mainly during early exponential growth of both planktonic and sessile cells. Thus, accumulation of levan in biofilm voids hints to a function as a nutrient storage source for later stages of biofilm development. The presence of a third EPS besides levan and alginate was indicated by binding of the lectin from Naja mossambica to a fibrous structure in biofilms of all P. syringae derivatives. Production of the as yet uncharacterized additional EPS might be more important for biofilm formation than the syntheses of levan and alginate.

Alginates↗

PubMed1992

Effects of haemorrhage on bacterial antigen specific pulmonary plasma cell function.

Nosocomial pneumonia is frequent after haemorrhage and trauma, and often contributes to multiple organ system failure, morbidity and mortality in this setting. Although the percentages and numbers of bacterial polysaccharide antigen-specific pulmonary B cell clonal precursors are markedly decreased after haemorrhage, the effects of haemorrhage on pulmonary plasma cells actually producing antibody to these antigens are unknown. To investigate this question, the numbers of intraparenchymal pulmonary plasma cells producing antibody against the bacterial polysaccharide antigen levan (from Aerobacter levanicum) as well as bacterial antigen specific secretory IgA (sIgA) titres in the lungs were determined at various time points after 30% blood volume haemorrhage. Reduced numbers of bacterial antigen specific pulmonary plasma cells were found for more than 21 days following haemorrhage. An almost complete disappearance from the lungs of levan specific plasma cells occurred between 3 and 21 days after blood loss. Titres of bacterial antigen specific sIgA in the lungs were decreased starting at 3 days post-haemorrhage and remained significantly depressed for more than 35 days after blood loss. These results demonstrate that haemorrhage produces profound and long-lasting suppression in bacterial antigen-specific pulmonary plasma cell function. Because these effects do not occur immediately post-haemorrhage, immunization techniques able to enhance bacterial antigen specific sIgA titres at pulmonary surfaces may be able to increase resistance to nosocomial pneumonia if administered shortly after injury and blood loss.

Animals↗

PubMed2004

Disruption of the Zymomonas mobilis extracellular sucrase gene (sacC) improves levan production.

AIMS: Disruption of the extracellular Zymomonas mobilis sucrase gene (sacC) to improve levan production. METHODS AND RESULTS: A PCR-amplified tetracycline resistance cassette was inserted within the cloned sacC gene in pZS2811. The recombinant construct was transferred to Z. mobilis by electroporation. The Z. mobilis sacC gene, encoding an efficient extracellular sucrase, was inactivated. A sacC defective mutant of Z. mobilis, which resulted from homologous recombination, was selected and the sacC gene disruption was confirmed by PCR. Fermentation trials with this mutant were conducted, and levansucrase activity and levan production were measured. In sucrose medium, the sacC mutant strain produced threefold higher levansucrase (SacB) than the parent strain. This resulted in higher levels of levan production, whilst ethanol production was considerably decreased. CONCLUSIONS: Zymomonas mobilis sacC gene encoding an extracellular sucrase was inactivated by gene disruption. This sacC mutant strain produced higher level of levan in sucrose medium because of the improved levansucrase (SacB) than the parent strain. SIGNIFICANCE AND IMPACT OF THE STUDY: The Z. mobilis CT2, sacC mutant produces high level of levansucrase (SacB) and can be used for the production of levan.

Culture Media↗