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 469 records · Page 26Linked to original sources
PubMed1994

An important role of heparan sulfate proteoglycan (Perlecan) in a model system for the deposition and persistence of fibrillar A beta-amyloid in rat brain.

A consistent rat model for the study of the consequences of congophilic and fibrillar A beta-amyloid in brain has been developed. One hundred percent of animals receiving infusions of synthetic beta-amyloid protein (A beta 1-40) plus a specific heparan sulfate proteoglycan (HSPG) for 1 week or 7 weeks (following 2 week infusions) demonstrated Congo red and thioflavin S-positive deposits adjacent to the infusion site. Extracellular amyloid fibrils were identified by electron microscopy and were immunogold decorated with A beta antibody. Significant increases in Congo red staining were observed in animals infused with A beta plus HSPG versus those infused with only A beta. Infusion of A beta alone was variable with respect to congophilic amyloid persistence, which occurred in 50% of animals and only when endogenous HSPGs accumulated at A beta deposition sites. By 7 weeks, only animals infused with A beta plus HSPG demonstrated compaction of the Congo red material from amorphous, wispy deposits (at 1 week) to stellate deposits resembling a Maltese cross. These spherical amyloid deposits were very similar to Congo red-stained amyloid plaques in human Alzheimer's disease brain, and in vitro data suggest that they were probably formed in vivo following interactions with endogenous brain components.

Amyloid beta-Peptides↗
PubMed1977

Structural similarities between a protein extracted from normal human tissues and a component of amyloid fibrils.

Comparative immunologic and chemical studies of crude or fractionated amyloid fibrils and materials obtained from corresponding normal tissues have been performed. Materials from the amyloidotic and normal tissues were subjected to identical methods of extraction, chemical treatment and protein fractionation. Antigenic similarities between crude amyloid fibrils and corresponding normal tissue extracts were observed, however, a considerably larger concentration of the latter antigens was needed to obtain immunologic reactivity in double diffusion in gel. Striking similarities were observed when the amino acid composition of a high molecular weight subcomponent of amyloid fibrils was compared with that of normal tissue extracts. Crude, intact amyloid fibrils were highly effective in absorbing Congo-red while the ability to absorb Congo-red was by far less if the high molecular weight subcomponent of amyloid fibrils as well as the corresponding normal tissue extracts were used. The high molecular weight subcomponent of amyloid, which seems to be an integral part of the amyloid fibrils, most probably is a protein derived from normal tissue.

Adult↗
PubMed2005

[Congo red-negative light chain disease with intractable diarrhea].

A 56-year-old man was admitted due to chronic diarrhea with progressive weight loss (30 kg within 1 year). All results of medical investigations were normal. The suspected diagnosis of a neuroendocrinological neoplasm could not be established; there was also no evidence for a lymphoma or amyloidosis. Chronic diarrhea and weight loss persisted over the ensuing weeks. Additionally, impairment of renal function and heart insufficiency with consecutive pericardial effusion as well as peripheral facial paralysis and peripheral neuropathy could be observed. Six months after hospital admission, the patient died due to progressive multiple organ failure. Postmortem examination revealed normal bone marrow. Only with additional immunohistochemical investigations of all organs could the diagnosis of a systemic Congo red-negative light chain disease be established.

Amyloidosis↗
PubMed1997

Detection of the intercellular adhesion gene cluster (ica) and phase variation in Staphylococcus epidermidis blood culture strains and mucosal isolates.

Staphylococcus epidermidis is a common cause of catheter-associated infections and septicemia in immunocompromised patients. To answer the question whether S. epidermidis skin isolates differ from isolates causing septicemic diseases, 51 strains obtained from blood cultures, 1 strain from shunt-associated meningitis, and 36 saprophytic isolates were characterized. The study demonstrates that most of the blood culture strains formed a multilayered biofilm on plastic material, whereas skin and mucosal isolates did not. Moreover, biofilm-producing strains were found to generate large bacterial autoaggregates in liquid culture. Autoaggregation and biofilm formation on polymer surfaces was associated with the presence of a DNA sequence encoding an intercellular adhesion gene cluster (ica) that mediates the production of a polysaccharide intercellular adhesin. The presence of the intercellular adhesion genes in blood culture isolates was also found to be correlated with the exhibition of black colonies on Congo red agar, whereas the adhesin-negative strains formed red colonies. Upon subcultivation on Congo red agar, the black colony forms of the blood culture strains exhibited red colony variants which were biofilm and autoaggregation negative and occurred at a frequency of 10(-5). The DNA analysis of these S. epidermidis variants by pulsed-field gel electrophoresis and Southern hybridization with an ica-specific gene probe revealed no detectable difference between the black and red colony types. Moreover, after repeated passage, the phenotype of the parent strain could be restored. Therefore, these colony forms were regarded as phase variants. This phenotypic change was observed exclusively in adhesin-positive clinical isolates and not in adhesin-negative saprophytic strains of S. epidermidis.

Bacteremia↗
PubMed2001

Enhanced in vitro production of amyloid-like fibrils from mutant (S20G) islet amyloid polypeptide.

UNLABELLED: Islet amyloid polypeptide (IAPP, "amylin") is the amyloid-fibril-forming polypeptide in the islets of Langerhans associated with type 2 diabetes mellitus. A missense mutation in the IAPP gene associated with early-onset type 2 diabetes has been identified in the Japanese population. This mutation results in a glycine for serine substitution at position 20 of the mature IAPP molecule. Whether or not formation of islet amyloid with resulting destruction of islet tissue is the cause of this diabetes is yet not known. The present in vitro study was performed in order to investigate any influence of the amino acid substitution on the fibril formation capacity. Synthetic full-length wild type (IAPPwt) and mutant (IAPPS20G) as well as corresponding truncated peptides (position 18-29) were dissolved in dimethylsulfoxide (DMSO) or in 10% acetic acid at a concentration of 10 mg/mL and their fibril forming capacity was checked by Congo red staining, electron microscopy, a Congo red affinity assay and Thioflavine Tfluorometric assay. It was found that full-length and truncated IAPPS20G both formed more amyloid-like fibrils and did this faster compared to IAPPwt. The fibril morphology differed slightly between the preparations. CONCLUSION: The amino acid substitution (S20G) is situated close to the region of the IAPP molecule implicated in the IAPP fibrillogenesis. The significantly increased formation of amyloid-like fibrils by IAPPS20G is highly interesting and may be associated with an increased islet amyloid formation in vivo and of fundamental importance in the pathogenesis of this specific form of diabetes.

Amyloid↗
PubMed1987

Amyloid deposition in systemic organs in long-term hemodialysis patients.

It has not been yet elucidated whether, in long-term hemodialysis patients, amyloid deposition in the transverse carpal ligament (TCL) is a symptom of systemic amyloidosis or a localized one. In 2 patients amyloid deposition was noted in the TCL which had been resected at operation, and we observed amyloid deposits also in other organs at autopsy after their deaths. In the two patients, no diseases resulting in secondary amyloidosis were observed. The unlabeled antibody peroxidase-antiperoxidase method (PAP method) served to reveal the deposits of beta 2-microglobulin (beta 2M) in the TCL and other organs comparable to the Congo red positive area. And the Congo red staining for the amyloid protein after potassium permanganate treatment was preserved. According to these results, the carpal tunnel syndrome (CTS) in long-term hemodialysis was considered as a symptom of systemic amyloidosis. Amyloid was deposited mainly in the vessel walls and the deposition was not circumferential but segmental.

Amyloidosis↗
PubMedDate not supplied

Effects of trypan blue and related compounds on production and activity of streptolysin S.

Most dyes related to trypan blue inhibited hemolytic activity of oligonucleotide-streptolysin S (SLS) complex, an exotoxin produced by Streptococcus pyogenes. Order of the inhibition was: trypan blue greater than benzo blue 2B greater than Congo red greater than Evans blue greater than benzo purpurine 4B greater than thiazine red greater than trypan red. When resting streptococcal cells were incubated with these dyes, significant amount of the hemolysin was produced. The carrier (or inducing) activity for SLS was further manifested in growing cell system and the potency of the compounds was as follows: Congo red greater than benzo blue 2B greater than trypan blue greater than Evans blue greater than Benzo purpurine 4B greater than or equal to thiazine red greater than trypan red. In this system, Congo red was more effective than oligonucleotide fraction rich in guanyl residue. Chromotrope 2B, H acid and o-tolidine were ineffective, as the carrier as well as the inhibitor. Based on these results, structure-function relationship among SLS, the carrier and the inhibitor was discussed.

Animals↗
PubMed1979

The potassium permanganate method. A reliable method for differentiating amyloid AA from other forms of amyloid in routine laboratory practice.

Alterations in affinity of amyloid for Congo red after incubation of tissue sections with potassium permanganate, as described by Wright el al, were studied. The affinity of amyloid for Congo red after incubation with potassium permanganate did not change in patients with myeloma-associated amyloidosis, familial amyloidotic polyneuropathy, medullary carcinoma of the thyroid, pancreatic island amyloid, and cerebral amyloidosis. Affinity for Congo red was lost after incubation with potassium permanganate in tissue sections from patients with secondary amyloidosis and amyloidosis complicating familial Mediterranean fever (consisting of amyloid AA). Patients with primary amyloidosis could be divided into two groups, one with potassium-permanganate--sensitive and one with potassium-permanganate--resistant amyloid deposits. These two groups correlated with the clinical classification in typical organ distribution (presenting with nephropathy) and atypical organ distribution (presenting with cardiomyopathy, nephropathy, and glossopathy) and the expected presence of amyloid AA or amyloid AL. Potassium permanganate sensitivity seems to be restricted to amyloid AA. The potassium permanganate method can be important in dividing the major forms of generalized amyloidosis in AA amyloid and non-AA amyloid. This can be used for differentiating early stages of the disease and cases otherwise difficult to classify. It is important to define patient groups properly, especially in evaluating the effect of therapeutic measures. (Am J Pathol 97:43--58, 1979).

Amyloid↗
PubMed2003

Suppression by polycyclic compounds of the conversion of human amylin into insoluble amyloid.

There is a significant correlation between the occurrence of pancreatic islet amyloid and beta-cell failure in advanced type II diabetes mellitus. Islet amyloid is composed primarily of the fibrillar form of the pancreatic hormone, amylin. Using thioflavin-T fluorescence binding and radioprecipitation assays, we investigated whether or not a series of small tricyclic compounds, tetracycline or Congo Red could interfere with the conversion of synthetic human amylin into its insoluble amyloid form. Of the compounds investigated, incubation of human amylin with a 20-fold molar excess of either Congo Red or Acridine Orange resulted in significant inhibition in the rate of amyloid formation. With Congo Red, maximal inhibition effectively occurred at a 1:1 molar ratio or greater over human amylin, whereas inhibition by Acridine Orange was dose-dependent. A 20-fold molar excess of the compound tetracycline also decreased insoluble amyloid content after extended incubation periods of approx. 20 h. Amyloid fibril morphology in the presence of tetracycline, as measured by transmission electron microscopy, was characterized by short fragmented fibrils compared with the longer and denser appearance of fibrils formed by amylin alone. These findings show that polycyclic compounds can suppress the formation of amyloid by human amylin, providing support for an alternative approach to peptide-based strategies by which islet amyloid formation could be modulated.

Acridine Orange↗
PubMed2003

Congo red-positive cardiac kappa-AL amyloidosis in plasmacytoma -- case report and review of the literature.

We report on a 51-year-old female patient who was diagnosed in 2001 as suffering from plasmacytoma. The patient had had complaints of bilateral carpal tunnel syndrome in 1999, treated by a simple dissection without performing histological examination. Congestive heart failure had gradually developed since that time. In 2001 echocardiography revealed a pronounced thickening of the left ventricular wall with systolic and diastolic dysfunction. A kappa-light chain M component and kappa-light chain-restricted bone marrow plasmacytosis were detected. Amyloid deposits staining positive in the kappa-light chain-restriction analysis were observed in a gastric biopsy. Taking into consideration all these findings, a plasmacytoma-associated systemic AL amyloidosis was diagnosed. Cyclophosphamide/prednisolone chemotherapy regimen led to complete haematological remission. Cardiac transplantation, combined with autologous peripheral blood stem cell graft, was considered as the next therapeutic step, but the patient died while on the waiting list for transplantation. Autopsy detected a highly hypertrophic myocardium with narrowed heart cavities. Microscopic examination revealed dense, pink, acellular, Congo red-staining and kappa-immunoperoxidase-positive AL amyloid masses splitting the cardiomyocytes. The present case is remarkable as it demonstrates that carpal tunnel syndrome and congestive heart failure could be symptoms of plasma cell dyscrasia-associated amyloidoses.

Adult↗
PubMed1986

Congophilia in cerebral amyloidosis is modified by inactivation procedures on slow transmissible pathogens.

Cerebral tissues with amyloid deposits were treated by various chemicals which inactivated the agent of subacute spongiform encephalopathy (SSE). We discovered Congophilia in the amyloid plaques in cases of Creutzfeldt-Jakob disease (CJD) and Gerstmann-Sträussler syndrome (GSS) correlated to the chemical inactivation profiles of SSE. After incubation with trichloroacetate, guanidine-SCN, guanidine-HCl, formic acid, phenol and autoclaving, amyloid plaques in unfixed frozen sections of human brains with CJD or GSS, lost the affinity of Congo red and green birefringence under polarized light. In formalin-fixed, paraffin-embedded tissue sections, amyloid plaques of CJD and GSS lost the affinity of Congo red after most of these treatments. On the other hand, senile plaques in the aged, patients with Alzheimer's disease and with senile dementia of the Alzheimer type did not lose the affinity of Congo red after most of these treatments. Therefore, the amyloid deposits in the amyloid plaques differ from those in senile plaques. The methods we used facilitate differentiation of amyloid and senile plaques in formalin-fixed, paraffin-embedded tissues.

Alzheimer Disease↗
PubMed1995

Amyloid in adrenal gland pheochromocytomas.

OBJECTIVE: To assess the frequency of amyloid deposits in adrenal gland pheochromocytomas. DESIGN: We evaluated 22 pheochromocytomas using routine hematoxylin-eosin and Congo red stains, polarization microscopy, and electron microscopy. Cases with amyloid were further characterized immunohistochemically. RESULTS: Congo red and polarization microscopy revealed characteristic apple-green birefringence, not abolished by potassium permanganate incubation, in only one neoplasm. In a subset of the remaining tumors, yellow or yellow-green birefringence not characteristic of amyloid was found. We performed electron microscopy on the tumor with characteristic apple-green birefringence and six other neoplasms with abundant yellow or yellow-green birefringence. Amyloid was identified in two tumors, including the Congo red-positive tumor, while the remaining five neoplasms contained collagen. Immunohistochemically, the amyloid deposits were reactive with component P and immunoglobulin kappa- and lambda-light chains in both tumors. Adsorption studies using human urine with monoclonal immunoglobulin kappa- or lambda-light chains abolished reactivity, consistent with specific immunostaining for both light chains. Transthyretin was present in one tumor. The neoplastic cells expressed chromogranin, neuron-specific enolase, and [Leu5]-enkephalin, although the amyloid was not reactive. CONCLUSIONS: We conclude that amyloid is infrequent in pheochromocytomas. Electron microscopic examination is more sensitive than Congo red stain and, in our opinion, is the best technique for the demonstration of amyloid deposits.

Adrenal Gland Neoplasms↗
PubMed2003

Pivotal role of oligomerization in expanded polyglutamine neurodegenerative disorders.

The expansion of a CAG repeat coding for polyglutamine in otherwise unrelated gene products is central to eight neurodegenerative disorders including Huntington's disease. It has been well documented that expanded polyglutamine fragments, cleaved from their respective full-length proteins, form microscopically visible aggregates in affected individuals and in transgenic mice. The contribution of polyglutamine oligomers to neurodegeneration, however, is controversial. The azo-dye Congo red binds preferentially to beta-sheets containing amyloid fibrils and can specifically inhibit oligomerization and disrupt preformed oligomers. Here we show that inhibition of polyglutamine oligomerization by Congo red prevents ATP depletion and caspase activation, preserves normal cellular protein synthesis and degradation functions, and promotes the clearance of expanded polyglutamine repeats in vivo and in vitro. Infusion of Congo red into a transgenic mouse model of Huntington's disease, well after the onset of symptoms, promotes the clearance of expanded repeats in vivo and exerts marked protective effects on survival, weight loss and motor function. We conclude that oligomerization is a crucial determinant in the biochemical properties of expanded polyglutamine that are central to their chronic cytotoxicity.

Adenosine Triphosphate↗
PubMed1995

Expression of two csg operons is required for production of fibronectin- and congo red-binding curli polymers in Escherichia coli K-12.

Two divergently transcribed operons in Escherichia coli required for the expression of fibronectin- and Congo red-binding curli polymers were identified and characterized by transposon mutagenesis, sequencing and transcriptional analyses, as well as for their ability to produce the curli subunit protein. The csgBA operon encodes CsgA, the major subunit protein of the fibre, and CsgB, a protein with sequence homology to CsgA. A non-polar csgB mutant is unaffected in its production of CsgA, but the subunit protein is not assembled into insoluble fibre polymers. A third open reading frame, orfC, positioned downstream of csgA may affect some functional property of curli since an insertion in this putative gene abolishes the autoagglutinating ability typical of curliated cells without affecting the production of the fibre. The promoter for the oppositely transcribed csgDEFG operon was identified by primer extension and shown, like the csgBA promoter, to be dependent upon the alternate stationary phase-specific sigma factor sigma s in wild-type cells, but not in mutants lacking the nucleoid associated protein H-NS. Insertions in csgD abolish completely trancription from the csgBA promoter. Therefore, any regulatory effect on the csgBA promoter might be secondary to events controlling the csgDEFG promoter and/or activation of CsgD. Insertions in csgE, csgF and csgG abolish curli formation but allow CsgA expression suggesting that one or more of these gene products are involved in secretion/assembly of the CsgA subunit protein. No amino acid sequence homologies were found between the CsgE, CsgF and CsgG proteins and secretion/assembly proteins for other known bacterial fibres, suggesting that the formation of curli follows a novel pathway.

Bacterial Proteins↗