Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Gluconates”

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.

At least 1,621 records · Page 90Linked to original sources
PubMed2003

Global metabolic regulation analysis for Escherichia coli K12 based on protein expression by 2-dimensional electrophoresis and enzyme activity measurement.

Regulation of the main metabolic pathways of Escherichia coli K12 was investigated based on 2-dimensional electrophoresis (2DE) and the measurement of enzyme activities. The cells were grown aerobically in different carbon sources, such as glucose, acetate, gluconate or glycerol. Microaerobic cultivation was also conducted with glucose as a carbon source. Fifty-two proteins could be identified based on 2DE, and 26 enzyme activities from the main metabolic pathways-including glycolysis, pentose phosphate pathway, TCA cycle, Entner-Doudoroff pathway and fermentative pathway-were assayed. These enzyme activities, together with global and quantitative protein expression, gave us a clear picture of metabolic regulation. The results show that, compared with the control experiment with glucose as a carbon source under aerobic conditions, glycolytic enzymes were slightly up-regulated (<2-fold), TCA cycle enzymes were significantly down-regulated (2- to 10-fold), and fermentative enzymes such as pfl and adhE were highly up-regulated (>10-fold) under microaerobic conditions in glucose medium. When acetate was used as a carbon source, pfkA, pykF, ppc and zwf were down-regulated, while fbp, pckA, ppsA and mez were significantly up-regulated. Glyoxylate enzymes such as aceA and aceB were strongly up-regulated (>10-fold) and TCA-cycle-related enzymes were also up-regulated to some extent. With gluconate as a carbon source, edd, eda, fbp and TCA cycle enzymes were up-regulated. With glycerol as a carbon source, fbp and TCA cycle enzymes were up-regulated, while ackA was significantly down-regulated. Protein abundance obtained by 2DE correlated well with enzyme activity, with a few exceptions (e.g., isocitrate dehydrogenase), during aerobic growth on acetate.

Electrophoresis, Gel, Two-Dimensional↗
PubMed2005

Comparative study of promoters for the production of polyhydroxyalkanoates in recombinant strains of Wautersia eutropha.

Recombinant strains of Wautersia eutropha expressing an artificial polyhydroxyalkanoate (PHA) biosynthesis operon under the control of different native promoters linked to polyhydroxybutyrate (PHB) (P(phb)), acetoin (P(acoE), P(acoD), and P(acoX)) or pyruvate (P(pdhE)) metabolism were constructed and tested. The promoters were representative either of the enterobacterial sigma70 (P(phb), P(acoE), and P(pdhE))- or sigma54 (P(acoD) and P(acoX))-dependent promoters. To obtain polymers consisting of C4-C12 monomer units, an artificial operon consisting of the PHA synthase gene from Pseudomonas sp. 61-3 (phaC1 (Ps)) tandemly linked to the W. eutropha genes encoding beta-ketothiolase (phbA (We)) and nicotinamide adenine dinucleotide phosphate dependent acetoacetyl-coenzyme A (CoA) reductase (phbB (We)) was constructed. All recombinant strains produced PHA, indicating that the PHA biosynthesis genes were expressed under the control of the different promoters. Cell growth and PHA synthesis on MS medium complemented with gluconate or octanoate, and different concentrations of acetoin (0, 0.15, and 0.3%) clearly differed among the recombinant strains. While the P(acoD) and P(acoX) promoters mediated only low PHA yields (<1%) in the presence of the inducer acetoin, the remaining promoters-independent of the addition of acetoin-resulted in the production of PHA polymers with high 3HB fractions (90-100 mol%) and with high 3HO contents (70-86 mol%) from gluconate and octanoate, respectively. Interestingly, on octanoate-MS medium with 0.15% acetoin, the P(acoE) promoter mediated the synthesis of PHA with a relatively high 3HB fraction (48 mol%). While PHAs with high 3HB contents were obtained, the overall PHA product yields were low (<10%); thus, their potential application for further commercial exploitation appears limited.

Acetoin↗
PubMed2000

Homologous functional expression of cryptic phaG from Pseudomonas oleovorans establishes the transacylase-mediated polyhydroxyalkanoate biosynthetic pathway.

Various pseudomonads are capable of the synthesis of polyhydroxyalkanoate (PHA), composed of medium chain length (MCL) 3-hydroxy fatty acids (C6-C14), when grown on simple carbon sources such as, for example, gluconate or acetate. In Pseudomonas putida, the fatty acid de novo synthesis and PHA synthesis are linked by the transacylase PhaG. Southern hybridization experiments with digoxigenin-labeled phaG(Pp) from P. putida and genomic DNA from various pseudomonads indicate that phaG homologues are present in various other pseudomonads. Although P. oleovorans does not accumulate PHA(MCL) from non-related carbon sources, its genomic DNA reveals a strong hybridization signal. We employed PCR to amplify this phaG homologue. The respective PCR product comprising the coding region of phaG(Po) was cloned into pBBR1MCS-2, resulting in plasmid pBHR84. DNA sequencing revealed that putative PhaG(Po) from P. oleovorans exhibited about 95% amino acid sequence identity to PhaG(Pp) from P. putida. Reverse transcriptase-PCR analysis demonstrated that phaG(Po) was not transcribed even tinder inducing conditions, i.e. in the presence of gluconate as carbon source, whereas induction of phaG(Pp) transcription was obtained in P. putida. When octanoate was used as sole carbon source, only low levels of phaG mRNA were detected in P. putida. Plasmid pBHR84 complemented the phaG-negative mutant PhaG(N)-21 from P. putida. Interestingly, reintroduction of phaG(Po) under lac promoter control into the natural host P. oleovorans established PHA(MCL) synthesis from non-related carbon sources in this bacterium. These data indicated that phaG(Po) in P. oleovorans is not functionally expressed and does not exert its original function.

Acyltransferases↗
PubMed2006

Effects of peritoneal lavage with scolicidal agents on survival and adhesion formation in rats.

Intraoperative irrigation of the peritoneal cavity with scolicidal agents is frequently recommended when dealing with traumatic or spontaneous rupture of hydatid cysts. The present experimental study was designed to examine the influence of various scolicidal agents on adhesion formation and survival. A total of 149 rats were randomly allocated to nine groups. Peritoneal lavage through a median laparotomy was performed with the following scolicidal agents. Group 1 (0.9% saline: controls), group 2 (20% hypertonic saline), group 3 (0.04% chlorhexidine gluconate), group 4 (3% hydrogen peroxide), group 5 (0.5% silver nitrate), group 6 (1% polyvinylpyrrolidone-iodine, or PVP-I ), group 7 (5% PVP-I), group 8 (0.5% cetrimide/0.05% chlorhexidine), and group 9 (10% PVP-I). The surviving animals were sacrificed on postoperative day 15. Adhesion formation was macroscopically graded by the Nair criteria. The severity of adhesion formation was evaluated microscopically using the fibrosing scoring criteria and the strain test. Group 9 (10% PVP-I) was excluded from the adhesion evaluation because all of the rats died in this group. The mortality rate was significantly higher in groups 5 and 7 than in groups 1, 2, 3, 4, 6, and 8. Adhesion scores were significantly lower in groups 1, 2, 3, and 4 than in groups 5, 6, 7, and 8. The lowest adhesion score was found in group 3 and the highest in the group 7. These results indicate that 0.04% chlorhexidine gluconate, the most potent scolicidal agent in vitro and in vivo, was associated with the lowest adhesion formation and mortality among various scolicidal agents in this experimental study.

Animals↗
PubMed2004

Increased postoperative peritoneal adhesion formation after the treatment of experimental peritonitis with chlorhexidine.

BACKGROUND AND AIMS: Chlorhexidine is known as a substance that produces adhesions. However, in an experimental model of peritoneal injury, lavage with chlorhexidine and saline solutions produced a similar number of adhesions. This study was designed to test the hypothesis that chlorhexidine gluconate 0.05% solution used for the treatment of peritonitis increases formation of postoperative peritoneal adhesions as compared to standard lavage with saline solution. MATERIAL AND METHODS: Forty Wistar rats were randomly allocated to gastric or faecal peritonitis groups. In each group rats were further randomly subdivided into saline or chlorhexidine peritoneal lavage groups. After 30 days the rats were killed and intraperitoneal adhesions were evaluated by adhesion score and grading. RESULTS: Adhesion scores were statistically significantly different between saline and chlorhexidine groups in both gastric and faecal peritonitis models. In the faecal peritonitis chlorhexidine group a 20% small bowel intussusception rate was observed, while there were no such complications in the other study groups. The conglomerate of organs formed by dense adhesions was present in 60% of cases when gastric peritonitis was lavaged by chlorhexidine and in only 10% when saline solution was used ( P<0.05). Neither chlorhexidine nor saline solutions have caused such dense adhesions in faecal peritonitis. CONCLUSION: Peritoneal lavage with chlorhexidine gluconate 0.05% solution in the treatment of experimental peritonitis results in increased adhesion formation.

Animals↗
PubMed2002

An outwardly rectifying anion channel in human leukaemic K562 cells.

In this study, an outwardly rectifying anion channel was characterized in the cell line K562 obtained from a chronic human leukaemia. Ion channel activity was recorded in the cell-detached (inside-out) configuration with standard patch-clamp technology. In most of the K562 cells studied, the channel exhibited low spontaneous activity, an outwardly rectifying current/voltage relationship and single-channel conductances of 19 pS and 40 pS for inwards and outwards currents respectively. The channel had a low permeability for gluconate with a relative permeability P(gluconate)/ P(Cl) of 0.14 and was blocked by glibenclamide (50 micro M) or diphenylamine-2-carboxylate (DPC, 1 mM) added to the cytoplasmic side of the patch. These results are characteristic of the outwardly rectifying Cl channel (ORCC) found in other types of cells.

Anions↗
PubMed1997

Chloride channels in the luminal membrane of rat pancreatic acini.

Pancreatic acini secret Na+, Cl- and H2O in response to secretagogues such as acetylcholine. Cl- channels in the luminal membrane are a prerequisite for this secretion. The properties of the corresponding conductance have previously been examined using whole-cell recordings. The present study attempts to examine the properties of the single channels in cell-attached and cell-free excised patches from the luminal membrane. To this end the pipettes were filled with an N-methyl-D-glucamine (NMDG+) chloride-gluconate solution. The voltage-clamp range was chosen to be pipette positive (cell negative, -60 to -130 mV) in order to increase the driving force for outward Cl- currents. Under resting conditions cell attached luminal patches had very few single-channel currents (12 out of 45 experiments). Their incidence was sharply increased by carbachol (CCH, 1 micromol/l) in 41 out of 45 experiments. The single-channel conductance of these channels was 1.97 +/- 0.05 pS. The properties of these channels in excised patches were examined further: their single-channel conductance was 2.2 +/- 0.07 pS (n = 59) and their conductance selectivity was I- > Br- > Cl- >> gluconate. None of the typical Cl- channel blockers (DIDS, NPPB, glibenclamide 100 micromol/l) blocked these channels. It is concluded that the luminal membrane of the rat pancreatic acinus possesses Cl- channels with very low conductance which are activated by carbachol.

Animals↗
PubMed2000

Physiological evidence for differently regulated tryptophan-dependent pathways for indole-3-acetic acid synthesis in Azospirillum brasilense.

Disruption of ipdC, a gene involved in indole-3-acetic acid (IAA) production by the indole pyruvate pathway in Azospirillum brasilense Sp7, resulted in a mutant strain that was not impaired in IAA production with lactate or pyruvate as the carbon source. A tryptophan auxotroph that is unable to convert indole to tryptophan produced IAA if tryptophan was present but did not synthesise IAA from indole. Similar results were obtained for a mutant strain with additional mutations in the genes ipdC and trpD. This suggests the existence of an alternative Trp-dependent route for IAA synthesis. On gluconate as a carbon source, IAA production by the ipdC mutant was inhibited, suggesting that the alternative route is regulated by catabolite repression. Using permeabilised cells we observed the enzymatic conversion of tryptamine and indole-3-acetonitrile to IAA, both in the wild-type and in the ipdC mutant. IAA production from tryptamine was strongly decreased when gluconate was the carbon source.

Artificial Gene Fusion↗
PubMed1984

Effect of the preparation method on Na+-H+ exchange and ion permeabilities in rat renal brush-border membranes.

The delta pH-dependent quenching of Acridine orange was used to characterize Na+-H+ exchange and K+ and H+ conductances in brush-border membrane vesicles isolated by precipitation with either CaCl2 or MgCl2 from rat kidney cortex. A transmembrane pH difference of 2.5 units (inside acidic) was imposed and the initial rate of its dissipation was followed after injecting a puls of tetramethylammonium gluconate (control) or sodium or potassium gluconate. In membranes isolated by CaCl2, the Na+-H+ exchange was partially electroneutral (45% to 77% of the total exchange) and the rest was due to electrically coupled Na+ and H+ movements through conductive pathways in the membranes. In membranes prepared by MgCl2, the rate of total Na+-H+ exchange was about twice as high as that in membranes obtained by CaCl2 precipitation. However, total and electroneutral exchanges were equal indicating negligible electrically coupled Na+ and H+ movements in these membranes. K0.5 for Na+ in all preparations was in the same range, being in average 30 mM. Amiloride was a competitive inhibitor of Na+-H+ exchange in membranes obtained with both preparations; Ki values ranged between 0.1 and 0.58 mM. The rates of delta pH-dissipation with K+ gradients (+/- valinomycin) were by 50% to 150% higher in membranes prepared with CaCl2 than in membranes isolated with MgCl2 indicating much higher H+ and K+ conductances in membranes obtained with CaCl2. Therefore, the rate of Na+-H+ exchange as well as the conductances for various ions in the isolated brush-border membranes depend on membrane preparation.

Amiloride↗
PubMed1991

Transport-related modulation of the membrane properties of toad urinary bladder epithelium.

Impedance analysis and transepithelial electrical measurements were used to assess the effects of the apical membrane Na+ channel blocker amiloride and anion replacement on the apical and basolateral membrane conductances and areas of the toad urinary bladder (Bufo marinus). Mucosal amiloride addition decreased both apical and basolateral membrane conductances (Ga and Gbl, respectively) with no change in membrane capacitances (Ca and Cbl). Consequently, the specific conductances of these membranes decreased without significant changes in membrane area. Following amiloride removal, an increase was obtained in the steady-state rate of sodium transport compared to values before amiloride addition. This increase was independent of the initial transport rate, suggesting activation of a quiescent pool of apical sodium channels. Chloride replacement by acetate or gluconate had no significant effects on apical or basolateral membrane capacitances. The effects of these replacements on membrane conductances depended on the anion species. Gluconate (which induces cell shrinkage) decreased both membrane conductances. In contrast, acetate (which induces cell swelling) increased Ga and had no effect on Gbl. The increase in the apical membrane conductance was due to an increase in the amiloride-sensitive Na+ conductance of this membrane. In summary, mucosal amiloride addition or chloride replacements led to changes in membrane conductances without significant effects on net membrane areas.

Amiloride↗
PubMed1992

Analysis of Macrocystis pyrifera and Pseudomonas aeruginosa alginic acids by the reductive-cleavage method.

Permethylated alginic acids comprised of 4-linked D-mannopyranosyluronic acid and 4-linked L-gulopyranosyluronic acid residues undergo reductive cleavage to yield, after acetylation, methyl 3-O-acetyl-2,6-anhydro-4,5-di-O-methyl-D-mannonate (2b) and methyl 3-O-acetyl-2,6-anhydro-4,5-di-O-methyl-D-gluconate (3b) as major products. Small amounts (ca. 13%) of ring-contracted products, namely methyl 2-O-acetyl-3,6-anhydro-4,5-di-O-methyl-D-mannonate (9) and methyl 2-O-acetyl-3,6-anhydro-4,5-di-O-methyl-D-gluconate (10), were also observed in these experiments. These results are in marked contrast to previous results on the reductive cleavage of 4-linked D-glucopyranosyluronic acid residues, wherein the ring-contracted product was formed exclusively. Formation of the ring-contracted products could be completely eliminated by reduction (LiAlH4) of ester groups in the permethylated alginic acid prior to reductive cleavage. In the latter experiments, 4,6-di-O-acetyl-1,5-anhydro-2,3-di-O-methyl-D-mannitol (5b) and 4,6-di-O-acetyl-1,5-anhydro-2,3-di-O-methyl-L-gulitol (6b) were the sole products of reductive cleavage of the 4-linked ManA and 4-linked GulA residues, respectively. However, in the previous experiments it was noted that low yields of permethylated alginic acids were obtained and that extensive depolymerization occurred under methylation conditions. Depolymerization could be avoided and higher yields of permethylated polysaccharides could be obtained, by reduction of the carboxyl groups of the alginic acids prior to methylation. Reductive cleavage of the latter polysaccharides yielded the products expected from 4-linked D-mannopyranosyl and 4-linked L-gulopyranosyl residues, namely 4-O-acetyl-1,5-anhydro-2,3,6-tri-O-methyl-D-mannitol (13b) and 4-O-acetyl-1,5-anhydro-2,3,6-tri-O-methyl-L-gulitol (14b), respectively. Using the latter analytical strategy, it was established that the Macrocystis pyrifera alginate was comprised of 60% 4-linked ManA and 40% 4-linked GulA residues, whereas the Pseudomonas aeruginosa alginate was comprised of 80% 4-linked ManA and 20% 4-linked GulA residues.

Alginates↗
PubMed1992

Enhancement of antimicrobial properties of cavity varnish: a preliminary report.

Bacterial contamination beneath amalgam restorations has been a problem in restorative dentistry. Cavity varnish improves the marginal seal but possesses no antibacterial properties, and chlorhexidine gluconate is a known antimicrobial substance. This study investigated the efficacy of a chlorhexidine gluconate/cavity varnish mixture against Streptococcus mutans, S. salivarius, and Escherichia coli. The in vitro results indicated that the addition of chlorhexidine gluconate to cavity varnish improved its antimicrobial properties.

Bacteria↗
PubMed1996

Activation of water-responsive laryngeal afferents: role of epithelial ion transport.

The role of epithelial ion transport in the activation of water-responsive laryngeal afferent was investigated in anesthetized, spontaneously breathing cats. Single-fiber recordings from the peripheral cut-end of the superior laryngeal nerve were carried out to identify water-responsive laryngeal afferent. Substitution of chloride ions (Cl-) of the Krebs solution with gluconate activated the water-responsive endings when the gluconate concentration was > or = 50 mM. Amiloride (10(-4), 10(-3) and 10(-2) M), an inhibitor of epithelial sodium channels, reduced the water-responsiveness of these afferents, whereas EIPA (5 x 10(-5) M), an amiloride analogue which inhibits Na+/H+ exchange, had no effect. Both ouabain (10(-4) M), an inhibitor of Na+/K+ ATPase, and bumetanide (10(-4) M), an inhibitor of Na(+)-K(+)-2Cl- cotransport, reduced the water response, but no significant reduction in the response was observed with DIDS and DPC, two chloride channel inhibitors. These findings suggest that the epithelium modulates the water-responsiveness of laryngeal afferent but is not the primary determinant of the response.

4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid↗
PubMed1995

A Mössbauer and X-ray powder diffraction study of some ferrous hematinics.

Iron deficiency anemia is a relatively common illness that can arise from a number of different causes. Three ferrous salts are usually used in its treatment: ferrous fumarate, gluconate, and sulfate. They are administered orally and are relatively well tolerated. These hematinics have been studied by Mössbauer spectroscopy and X-ray powder diffraction, and can easily be distinguished by both techniques. It was found that the two ferrous sulfates studied (Eckerd and SmithKline Beckman Co.) most closely resemble the monohydrate by comparison of the X-ray powder pattern with those of the JCPDS. Both the ferrous fumarate (Femiron) and gluconate (Spring Valley) had approximately 10% ferric iron present. To the authors' knowledge, this is the first reported Mössbauer spectrum for ferrous fumarate.

Ferrous Compounds↗
PubMed1989

K+-induced swelling of the dogfish shark (Squalus acanthias) rectal gland cells is associated with changes of the cytoskeleton.

Dogfish shark (Squalus acanthias) rectal gland cells swell massively when incubated in elasmobranch media in which Na+ was equivalently replaced by K+; this swelling was abolished when the impermeant gluconate replaced Cl-, while the cell depolarization was comparable in both media. The K+-effect was associated with (a) an increase of the steady-state 42K (and 86Rb) efflux (particularly of the rate constant of the fast cellular efflux component) and a rearrangement of the respective cellular pools of K+; (b) an alteration of cell morphology and the pattern of the F-actin staining along the basolateral cell membrane as revealed with fluorescent analogs of phallacidin. These changes were independent of cell volume, being identical in KCl and K-gluconate media. The observations were specific for K+ (and Rb+): replacement of media Na+ by Li+ (which is not actively extruded by the cells), or the presence of ouabain, produced only minor swelling without affecting cell morphology and F-acting distribution. The results are consistent with the following view: as opposed to Na+ or Li+ media, the K+-induced changes of the cortical F-actin component of the cytoskeleton permit the observed massive cell swelling due to the osmotic contribution of intracellular impermeant anion(s).

Actins↗
PubMed1992

Intergeneric protoplast fusion between Gluconobacter oxydans and Corynebacterium species.

Intergeneric protoplast fusion between 2,5-diketo-gluconic acid producing Gluconobacter oxydans (ATCC 9937) and a mutant strain of Corynebacterium species (ATCC 31090), capable of reducing 2,5-diketo-gluconic acid to 2-keto-L-gulonic acid, a penultimate step in vitamin C production) resulted in viable recombinants. Some of the fusion products exhibited the capacity to convert D-glucose to 2-keto-L-gulonic acid, but the conversion rate is low.

Acetobacteraceae↗
PubMed1988

Prevention of intraoperative wound contamination with chlorhexidine shower and scrub.

In a prospective, controlled, clinical trial, we found that preoperative showering and scrubbing with 4% chlorhexidine gluconate was more effective than povidone-iodine or triclocarban medicated soap in reducing skin colonization at the site of surgical incision. Mean log colony counts of the incision site were one half to one log lower for patients who showered with chlorhexidine compared to those who showered with the other regimens. No growth was observed on 43% of the post shower skin cultures from patients in the chlorhexidine group compared with 16% of the cultures from patients who had povidone-iodine showers and 5% of those from patients who used medicated soap and water. The frequency of positive intraoperative wound cultures was 4% with chlorhexidine, 9% with povidone-iodine and 14% with medicated soap and water. This study demonstrates that chlorhexidine gluconate is a more effective skin disinfectant than either povidone-iodine or triclocarban soap and water and that its use is associated with lower rates of intraoperative wound contamination.

Baths↗