Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “CONGO RED”

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 109 records · Page 6Linked to original sources
PubMed2006

Removal of congo red using activated carbon and its regeneration.

Activated carbon is used for the removal of colored toxic congo red dye. The effects of different operating conditions like, initial dye concentration, contact time, pH and temperature are studied for adsorption of congo red by a known amount of activated carbon (1.0g/L) under stirred batch condition. The zero point of charge of the activated carbon is found about 6.6. About 90% dye is removed for initial concentration of 50 and 100mg/L, it is about 80% at pH 7.0. Maximum adsorption (about 100%) of dye is observed at pH 2.0 for the concentration range studied here. Freundlich isotherm is found to fit the equilibrium data more adequately. Pseudo second order kinetic model explain successfully the kinetic data. The surfactant enhanced carbon regeneration (SECR) technique using both cationic and anionic surfactants is adopted for the regeneration of spent carbon by desorbing the dye. A kinetic model for dye desorption from the commercial activated carbon (CAC) is also proposed. Anionic surfactants show better performance than the cationic ones. Efficiency of dye desorption using surfactants is also compared with the desorption using pH change.

Adsorption↗
PubMed2000

Amyloid peptide channels: blockade by zinc and inhibition by Congo red (amyloid channel block).

Amyloid peptides are the major constituents of amyloid deposits in various amyloid diseases including Alzheimer's disease, type II diabetes mellitus, prion diseases and others. The hallmark of amyloid is the binding of the dye, Congo red, which creates characteristic staining due to the dye's ability to bind the beta sheet aggregates referred to as amyloid. Previous reports have demonstrated that several cytotoxic, amyloidogenic peptides can form ion channels in planar phospholipid bilayer membranes and have suggested that these channels may represent the pathogenic mechanism of cell and tissue destruction in amyloid disease. Furthermore, zinc and Congo red can ameliorate or prevent the pathogenic effect of certain amyloidpeptides. We report here that zinc at micromolar concentrations caused a reversible blockade of islet amyloid polypeptide (IAPP, amylin) and PrP 106-126 channels whereas calcium and magnesium did not. Congo red completely inhibited channel formation if preincubated with amyloid peptides, but had no effect on IAPP or PrP 106-126 channels once formed. These results suggest a requirement for aggregation for the formation of amyloid peptide channels and are consistent with the "channel hypothesis" of amyloid disease. They also suggest potential avenues for ameliorative therapy of these illnesses.

Amyloid↗
PubMed1988

Diagnosis of simultaneous multiple gastric cancers by the endoscopic Congo red--methylene blue test.

The clinicopathological features of simultaneous multiple gastric cancers, and the accuracy of their diagnosis by routine endoscopic examination were analyzed. In addition, the accuracies of diagnosis of coexisting early gastric cancers by routine endoscopic examination and by the endoscopic Congo red--methylene blue test developed in our hospital were compared. The results showed that multiple cancers occurred frequently in elderly male patients, in patients with early gastric cancer of the flat and elevated types and the depressed type without converging folds, and in patients with advanced cancer of Borrmann type I. These patients frequently have early cancers of the flat or depressed types without converging folds, and advanced cancers of Borrmann type I. The coexisting lesions are very difficult to diagnose by routine endoscopic examination: a correct diagnosis of coexisting early cancers was made in only 28.3% of the cases by routine endoscopic examination. But with the Congo red--methylene blue test, the diagnostic rate was raised significantly to 88.9%. In this test, Congo red and methylene blue are sprayed on the surface of the stomach and are bleached within 2 to 5 minutes on the surface of a tumor, but not on the surface of unaffected mucosa.

Aged↗
PubMed2006

[Study on the chemical reaction of DNA with Congo red].

The interaction of deoxyribonucleic acid(DNA) and Congo red (GGH) was investigated by UV-Vis spectrophotometry in Tris-HCl solution (pH 4.56). When DNA was added into GGH solution, the color of the system changed from red to purple, which indicated the formation of the DNA-GGH complex. The maximum absorption of the complex is at 600 nm. The molar absorptivity measured at this wavelength epsilon = 1.41 x 10(5) L x cm(-1) mol(-1), the maximum binding number is n = 32, and the detection limit is c = 8.04 x 10(-8) mol x L(-1). The basic reaction condition of best pH value, time, and temperature, and the interference of different materials on the system were also studied. The ionic strength could affect the absorption of the system. The interaction of small molecule and DNA, the molecule structure, and the relationship between the molecule conformation and the distribution of electron cloud were studied.

Congo Red↗
PubMed1982

Evaluation of vagotomy by the Hollander-Congo red test.

In the present study, the completeness of vagotomy in patients who underwent truncal and highly selective vagotomy is evaluated, comparing them with control groups of normal persons and patients with a duodenal ulcer. The evaluation was made by the Hollander test, followed by the endoscopic Congo red test, using the same hypoglycemic stimulus. Gastric acid production was higher in the patients with duodenal ulcer, followed by the normal persons. Lower acidity levels were obtained for patients with truncal vagotomy than for patients with highly selective vagotomy. During the Congo red test, we noted that the patients with truncal or highly selective vagotomy had small black spots in the gastric mucosa, except those having a recurrent ulcer, denoting incomplete vagotomy. Nevertheless, when we observed the appearance of the gastric mucosa, we noted a similar aspect for those having had a vagotomy and for normal persons. This appearance was completely different from the patients with a duodenal ulcer. We concluded that truncal vagotomy greatly reduces the level of gastric acid production, while highly selective vagotomy does so to a lesser extent. The endoscopic aspect of these patients during the Congo red test was similar to that for normal persons.

Adult↗
PubMed2006

Prion urine comprises a glycosaminoglycan-light chain IgG complex that can be stained by Congo red.

Light chain IgG, a known amyloidotic protein, is present in the urine of prion disease affected individuals in a protease resistant form. In addition, it was shown recently that prion urine samples comprise a significant excess of glycosaminoglycans. Since amyloidotic proteins and glycosaminoglycans are the major components of amyloid aggregates, a Congo red dot blot assay was developed for detection of Creutzfeldt-Jacob disease (CJD) in urine. This assay was also positive for about 10% of patients suffering from diseases such as Alzheimer disease, cerebrovascular attacks and multiple sclerosis, but negative for healthy controls. Both glycosaminoglycans and proteins such as light chain IgG were required for the binding of Congo red to the urine fractions, as shown by the fact that Proteinase K digestion of the samples either after guanidine or after choindrotinase abolished the Congo red signal from the CJD samples.

Carrier Proteins↗
PubMed1986

Influence of the virulence plasmid and the Congo red reaction on the antimicrobial susceptibility of Yersinia species.

Seventeen strains of Yersinia enterocolitica and related species were examined for their susceptibility to a variety of antimicrobial agents. Twelve of the strains were clinical isolates which carried a virulence plasmid; five were food isolates which lacked plasmids. When grown on agar containing Congo red or haemin, each strain yielded pigmented (CR+) and non-pigmented (CR-) variants. CR+ bacteria of clinical origin were virulent, whereas CR+ food isolates and all CR- bacteria were avirulent. The susceptibility of CR+ and CR- bacteria to the following agents was compared: ampicillin, chloramphenicol, latamoxef, nalidixic acid, novobiocin, polymyxin B, rifampicin, streptomycin, tetracycline and tobramycin. The results showed that bacteria which bound Congo red were more susceptible to each drug examined than their CR- counterparts. This relationship held regardless of whether the CR+ bacteria possessed a virulence plasmid or not. The findings suggest that binding of antimicrobial agents by yersiniae may parallel binding of haemin and Congo red.

Anti-Bacterial Agents↗
PubMed1992

Epidemiological studies of congo red Escherichia coli in broiler chickens.

This prospective cohort study was designed to confirm the association between Congo red binding Escherichia coli (CREC) and E. coli air sacculitis in commercial broilers. It was also designed to evaluate CREC as an air sacculitis risk factor and to explore the CREC relationship to other air sacculitis risk factors (poultry house temperature, air-ammonia levels, and presence of other diseases). In addition, this study was used to assess a possible role of the broiler-breeder flocks and hatchers in the spread of CREC air sacculitis. Congo red E. coli-associated airsacculitis risk was based on CREC exposure of the chicks in the hatchers. Breeder flocks with greater than 30 CREC colonies/plate from hatcher air sampling tests were placed in the high risk group; flocks with less than five CREC colonies/plate were placed in the low risk group. Increased risks of death due to air sacculitis (RR = 2.26), and increased death rates due to CREC air sacculitis (RR = 9.45) in high-risk flocks, identified CREC as an important air sacculitis risk factor. The attributable risk percent of CREC airsacculitis from hatcher exposure of CREC was 89.4%, pointing to the hatcher as the source of CREC infection. The association of specific broiler-breeder flocks to high levels of CREC in the hatchers, and subsequent air sacculitis, suggests that the broiler-breeders are the ultimate source of CREC.

Air Sacs↗
PubMed1982

The congo red test to determine completeness of vagotomy: clinical application.

Over the past 5 years, we have evaluated the Congo red test for vagal competence as to its reliability under varied clinical conditions both intraoperatively and postoperatively. Our technique has been useful and accurate in approximately 200 patients. Insuring completeness of vagotomy during the operation has been of use in 42 patients uncovering an unsuspected incomplete vagotomy in 4. In a series of 31 patients with recurrent ulcer symptoms, the documentation of the cause as well as the presence of the ulcer is possible with one simple maneuver--endoscopy. Furthermore, the test has been utilized postoperatively in over 100 patients to determine the longevity of a negative test as well as the clinical sequelae of apositive study. With a trend to more selective vagal section and a continuing significant incidence of recurrent ulceration, we are convinced that the congo red test is an important adjunct to the surgical care of ulcer patients.

Congo Red↗
PubMed2000

X-34, a fluorescent derivative of Congo red: a novel histochemical stain for Alzheimer's disease pathology.

X-34, a lipophilic, highly fluorescent derivative of Congo red, was examined as a histochemical stain for pathological changes in Alzheimer's disease (AD). X-34 intensely stained neuritic and diffuse plaques, neurofibrillary tangles (NFTs), neuropil threads, and cerebrovascular amyloid. Comparison to standard methods of demonstrating AD pathology showed that X-34 correlated well with Bielschowsky and thioflavin-S staining. X-34 staining of NFTs correlated closely with anti-TAU antibody staining. A 1:1 correspondence of X-34 and anti-A beta antibody staining of plaques and cerebrovascular amyloid was observed. Both X-34 and thioflavin-S staining were eliminated by formic acid pretreatment, suggesting that beta-sheet secondary protein structure is a necessary determinant of staining. X-34 may be a general amyloid stain, like Congo red, because it also stains systemic amyloid deposits due to lambda-light chain monoclonal gammopathy. In conclusion, X-34 is a highly fluorescent marker for beta-sheet structures and intensely labels amyloid plaques, NFTs, neuropil threads, and vascular amyloid in AD brains. It can be used with both paraffin-embedded and frozen tissues as well as in combination with immunohistochemistry for double labeling. The intensity of staining and the simplicity and reproducibility of the technique suggest that it may be a useful addition to the standard techniques for evaluation of AD neuropathology. (J Histochem Cytochem 48:1223-1232, 2000)

Aged↗
PubMed2000

A beta fibrillogenesis: kinetic parameters for fibril formation from congo red binding.

Using Scatchard analysis, we have formulated as a function of time and pH the relationship between the binding of Congo red to Alzheimer's beta-amyloid and the aggregation number (i.e., monomer concentration within fibrils) as defined by nucleation-dependent self-assembly. This provides a basis on which to determine the kinetic parameters for fibril formation from the observed concentration of bound Congo red.

Amyloid beta-Peptides↗
PubMed1989

A 101-kilodalton heme-binding protein associated with congo red binding and virulence of Shigella flexneri and enteroinvasive Escherichia coli strains.

The ability of Shigella flexneri to bind Congo red or hemin is associated with virulence. A 101-kilodalton (kDa) protein responsible for this phenotype (Crb+) in S. flexneri was identified by a tetramethylbenzidine staining procedure which detects heme-protein complexes in polyacrylamide gels. Labeling of cell-surface polypeptides with 125I revealed that the 101-kDa heme-binding protein is expressed on the cell surface. Expression of the protein was regulated by growth temperature and was found to be encoded by the large virulence plasmid of S. flexneri. Deletion mutants and a Tn5 insertion mutant which were negative for Congo red binding (Crb-) did not express the 101-kDa protein. Enteroinvasive Escherichia coli strains that were Crb+, and whose plasmids shared homology with the S. flexneri virulence plasmid, also expressed the 101-kDa protein. Expression of the protein in S. flexneri and enteroinvasive E. coli correlated with the presence of a 9.2-kilobase EcoRI fragment of these plasmids.

Bacterial Proteins↗
PubMed1989

Modified sham feeding and Congo red test in determining completeness of vagotomy.

Gastric acid response to modified sham feeding was evaluated in 14 patients with duodenal ulcer prior to vagotomy and in 18 patients after vagotomy. Nine patients in the latter group had recurrent ulcer, suggesting inadequate vagotomy. Based on values in the 32 tests (14 pre and 18 postoperative), cut-off levels of six secretory indices were selected to provide a specificity of 1.00 for the presence of ulcer. When applied separately to the 18 postoperative patients and to the 13 patients who underwent the endoscopic congo red test, observed volume of 75 ml/h and peak volume of 90 ml/h following sham feeding gave specificity, sensitivity and efficiency of 1.00 each in determining inadequate vagotomy. The endoscopic congo red test done in 13 post-vagotomy cases showed a sensitivity of 1.00, and high specificity (0.89) and efficiency (0.92). Measurement of crude gastric juice response to modified sham feeding is a convenient bedside test to confirm inadequate vagotomy. The endoscopic congo red test is also useful, especially as a screening test, and has the added advantage that it can be used intra-operatively.

Adult↗
PubMed1987

Epidemiological study of the relationship between Congo red binding Escherichia coli and avian colisepticemia.

An epidemiological prospective (longitudinal) study design was used to evaluate the association of Congo red positive Escherichia coli and avian colisepticemia. High and low risk exposure groups of chickens were identified at hatching, and placed in separate identical houses on the same farm. Approximately 14,000 birds were placed in each house for the seven week grow-out period, during which all birds which died were necropsied and cultured, together with a representative sample of birds which were culled weekly. The findings implicated Escherichia coli as the etiological agent of avian colisepticemia. A relative risk of 6.5 and attributable risk of 73.5% supported the hypothesis that the Congo red medium identifies a virulent form of Escherichia coli which causes airsacculitis-colisepticemia in poultry.

Air Sacs↗
PubMed2005

Acetylcholinesterase-amyloid-beta-peptide interaction: effect of Congo Red and the role of the Wnt pathway.

The cholinergic system impairment observed in Alzheimer's disease (AD) patients leads to the cognitive, global and behavioral dysfunction commonly associated with dementia. The only treatment for AD has been the use of inhibitors of acetylcholinesterase (AChE) (E.C. 3.1.1.7), which is one of the several proteins associated with amyloid plaque deposits. Recently, novel dual inhibitors of AChE have been developed that target both the active site of the enzyme as well as the peripheral anionic site (PAS). Such inhibitors prevent the aggregation of amyloid-beta-peptide (Abeta) into Alzheimer's fibrils. The incorporation of AChE, as a "chaperone" into amyloid aggregates results in the modification of the biochemical properties of the enzyme, including: sensitivity to low pH, inhibition at high substrate concentration, and increases of the Abeta neurotoxicity. Congo Red dye stabilizes the Abeta monomer, is able to inhibit oligomerization, and inhibits the binding of AChE to Abeta. However no effect of Congo Red on the binding of AChE to the Abeta preformed fibrils was observed. These studies suggest that different interactions between Abeta soluble-AChE and Abeta fibrils-AChE take place during the association between them. Docking studies were performed to evaluate the binding of Congo Red to Abeta in order to identify putative binding sites in the Abeta monomer that might interact with AChE. The binding site involves a region between residues 12 and 16. Finally, recent studies are consistent with the idea that a attenuating beta-catenin loss of function of Wnt signaling components may play a role in the progression of neurodegenerative disease, such as AD, providing a connection between AChE-Abeta neurotoxicity and the Wnt signal transduction pathway.

Acetylcholinesterase↗
PubMed1994

An electron microscope and electron diffraction study of the effect of calcofluor and congo red on the biosynthesis of chitin in vitro.

The structure of chitin made in vitro by chitin synthetase was studied by electron microscopy and electron diffraction. Two different forms of chitin synthetase from the fungus Mucor rouxii were tested: chitosomes and 16 S particles. The long chitin fibrils produced by chitosomes had a high degree of crystallinity as revealed by electron diffraction. Specimen regions made of largely parallel microfibril bundles produced distinct fiber diagrams, an indication that the chitin chains were aligned along the fibril axis. Microdiffractometry of the shorter chitin crystals synthesized by 16 S particles also showed a similar alignment of chitin chains. Calcofluor and Congo red were powerful inhibitors of chitin synthetase and had profound effects on the color, macroscopic texture, electron microscopic morphology, and crystal structure of the biosynthesized chitin. Chitin made in the presence of Congo red had a bright red color; the one made in the presence of Calcofluor was strongly fluorescent and had a distinctly blue hue when illuminated by daylight. The dyes were tightly bound to the chitin and could not be removed by washing with water or ethanol. At low dye concentration, a mixture of two kinds of crystals was produced by 16 S particles: some were of the same dimensions as those made in the absence of dyes, but others were much thinner. At high dye concentration, there were only thin crystals. With increasing concentrations of Calcofluor or Congo red, the typical electron diffraction reflections of alpha-chitin, particularly the strong equatorial band at 0.466 nm became fainter and a new additional reflection centered at 0.40 nm arose as the dominant feature of the patterns. We regard the gel-like material, synthesized at highly inhibitory dye concentrations, as an apposition complex where the dye does not form part of the crystal structure of chitin and the bulk of the complex consists of molecular stacks of dye associated with nascent chitin chains or narrow chitin microfibrils.

Benzenesulfonates↗
PubMed1992

A 4-kilobase congo red binding plasmid DNA fragment of Shigella dysenteriae 1 suppresses the growth and cell differentiation in Escherichia coli.

A 4-kilobase congo red binding plasmid DNA fragment of pCAT 120 of Shigella dysenteriae 1 was transferred to an Escherichia coli K12 strain by transformation. Transformants were unable to grow in any liquid broth medium. Electron microscopic studies revealed that the transformants grown on tryptic soy agar were associated in clusters after cell division. Normal cell separation among the transformants in comparison with recipient E. coli K12 was only observed when the growth medium was supplemented with sterile culture filtrate of the recipient strain. An unknown factor(s) required for cell separation located on the chromosome was suppressed by a 4-kb congo red binding plasmid DNA (pCAT 120) fragment of S. dysenteriae 1.

Cell Division↗
PubMed2003

Decolorization of Congo Red with three-dimensional flow-by packed-bed electrodes.

The electrochemical removal of the color of the dyestuff Congo Red was investigated experimentally by using packed graphite anodes as well as packed graphite or C-304 stainless steel cathodes in an undivided reactor. The effects of the applied apparent current density, the amount of chloride ion addition, the pH value of the solution, the cathode material, the operating temperature, the volumetric flow rate and the initial concentration of Congo Red on the removal efficiencies were investigated in this study. Experimental results showed that the main pathway of color removal was by the hypochlorite generated in-situ at the anodes. Compared with the indirect oxidation, the color removal due to direct oxidation was insignificant. Cathodic oxidation by using graphite cathodes had little influence on the removal rate in an undivided electrochemical cell.

Coloring Agents↗