scholarly journals Amyloids, Congo red and the apple-green effect

2019 ◽  
Author(s):  
Anna Jagusiak ◽  
Joanna Rybarska ◽  
Leszek Konieczny ◽  
Barbara Piekarska ◽  
Barbara Stopa ◽  
...  
Keyword(s):  
Polyvinyl Alcohol ◽  
Congo Red ◽  
Amyloid Fibril ◽  
Polarized Light ◽  
Electron Delocalization ◽  
Supramolecular Organization ◽  
Spectral Variability ◽  
Spectral Changes ◽  
Strong Capacity ◽  
Nonlinear Increase

This paper attempts to find evidence of the previously proposed opinion that amyloids complex with Congo red molecules which preserve their supramolecular organization. As evidence of the overpowering tendency of Congo red molecules to self-assemble, we present an increasing acidity of molecules that follows increasing concentration of the dye, and a highly notable nonlinear increase in absorbance in the UV band (300–400 nm). This effect is analyzed in a model where the amyloid fibril is simulated by polyvinyl alcohol, providing a scaffold to stabilize a long Congo red micelle. Enormous absorbance in the UV band, coupled with the increasing association capabilities of individual Congo red molecules may cause the absorbance to extend even into the visible band. In addition, the UV and visual absorbance bands shift significantly, depending on conditions, and may either approach or recede from each other, leading to spectral changes which may be observed under polarized light. This commonly observed spectral variability appears to be associated with the strong capacity for electron delocalization in supramolecular Congo red complexed with amyloids.

scholarly journals Insights into the Photophysics and Supramolecular Organization of Congo Red in Solution and the Solid State

ChemPhysChem ◽  
2017 ◽  
Vol 18 (5) ◽  
pp. 564-575 ◽  
Author(s):  
Ana L. Costa ◽  
Ana C. Gomes ◽  
Martyn Pillinger ◽  
Isabel S. Gonçalves ◽  
João Pina ◽  
...  
Keyword(s):  
Solid State ◽  
Congo Red ◽  
Supramolecular Organization

scholarly journals Histochemical Differential Diagnosis and Polarization Optical Analysis of Amyloid and Amyloidosis

2006 ◽  
Vol 6 ◽  
pp. 154-168 ◽  
Author(s):  
M. Bély
Keyword(s):  
Differential Diagnosis ◽  
Congo Red ◽  
Early Recognition ◽  
Polarized Light ◽  
Optical Analysis ◽  
Early Start ◽  
Amyloid Deposits ◽  
Protein Fibrils ◽  
Congo Red Staining ◽  
Sensitive Method

Amyloidosis is characterized by extracellular deposition of protein fibrils of chemically heterogeneous composition. Early recognition and identification of amyloid deposits allows an early start of therapy, which may entail a better prognosis. Congo red staining according to Romhányi (1971) is a highly specific and sensitive method for early microscopic recognition of amyloidosis. The main and most important types of amyloidosis may be distinguished by classic histochemical methods of performate pretreatment according to Romhányi (1979), or by KMnO4oxidation according to Wright (1977) followed by Congo red staining and viewed under polarized light. Differences in the speed of breakdown (disintegration) of amyloid deposits according to Bély and Apáthy allow a more precise distinction of various types of amyloid.

Polyvinyl alcohol gelling systems. I. Congo red and related dyes

1955 ◽  
Vol 18 (88) ◽  
pp. 275-298 ◽  
Author(s):  
C. Dittmar ◽  
W. J. Priest
Keyword(s):  
Polyvinyl Alcohol ◽  
Congo Red

scholarly journals Cutaneous Amyloidosis: A Pilot Study at a Teaching Hospital in New Delhi

2017 ◽  
Vol 19 (1) ◽  
pp. 35-39
Author(s):  
Zeeba S Jairajpuri ◽  
Safia Rana ◽  
Shaan Khetrapal ◽  
Pooja Arora ◽  
Sujata Jetley
Keyword(s):  
Pilot Study ◽  
Congo Red ◽  
Polarized Light ◽  
New Delhi ◽  
Histologic Diagnosis ◽  
Systemic Involvement ◽  
Extracellular Compartment ◽  
Macular Amyloidosis ◽  
Skin Biopsies ◽  
One Year

Background: Amyloidosis is characterized by the deposition of polymeric fibrillar proteins in the extracellular compartment in tissues and organs ultimately leading to damage with functional compromise. Cutaneous amyloidosis is clinically classified into more common macular, papular, and the rarer nodular form. The present study was undertaken with the aim to histopathologically analyze and characterize clinically diagnosed amyloid cases.Methods:The present study was a retrospective analysis of skin biopsies conducted over a one year period. Data on the age and presenting clinical features were retrieved from the accompanying laboratory request forms or patients records wherever available. All skin biopsies with a histologic diagnosis of amyloid were retrieved and reviewed, the pattern of amyloid deposition identified and classified. Special stains including Congo Red stain was done in all the cases.Results: Histopathological confirmation of cutaneous amyloidosis was seen in nine out of fourteen cases and was confirmed by positive Congo-red stain under polarized light. Out of this seven were females and two were males. Majority of the lesions were of macular type. In all the nine cases, family history was negative and no evidence of systemic involvement was noted, either clinically or based upon the lab investigations.Conclusions: In this pilot study of 9 cases, histologically diagnosed as cutaneous amyloidosis we noted a female preponderance in young and middle-aged persons. Macular amyloidosis was the most common form and the most common site of involvement, the upper extremity and the inter-scapular/back region.J MEDICINE Jan 2018; 19 (1) : 35-39

scholarly journals DETERMINATION OF THE POLARIZATION OPTICAL PROPERTIES OF THE AMYLOID-CONGO RED COMPLEX BY PHASE MODULATION MICROSPECTROPHOTOMETRY

1974 ◽  
Vol 22 (12) ◽  
pp. 1105-1112 ◽  
Author(s):  
DOUGLASS L. TAYLOR ◽  
ROBERT D. ALLEN ◽  
EARL P. BENDITT
Keyword(s):  
Circular Dichroism ◽  
Congo Red ◽  
Phase Modulation ◽  
Optical Rotation ◽  
Polarized Light ◽  
Visible Spectrum ◽  
Linear Dichroism ◽  
Cotton Effect ◽  
Optical Rotatory Dispersion ◽  
Circular Dichroïsm

The polarization properties responsible for the classical "green birefringence" of the amyloid-Congo red complex have been determined by a new optical method, phase modulation microspectrophotometry. This method now makes possible the measurement of one optical property at a time (birefringence, optical rotation, linear dichroism and circular dichroism throughout the visible spectrum) in complex specimens in which visible contrast in polarized light is the result of a mixture of polarization effects. The green birefringence is explained by a combination of optical effects, the strongest of which are dispersion of birefringence and linear dichroism superimposed on the smaller effects of circular dichroism and optical rotatory dispersion. The interaction of the planar dye molecules with the amyloid protein induces an extrinsic Cotton effect.

scholarly journals Formation of amyloid-like aggregates through the attachment of protein molecules to a Congo red scaffolding framework ordered under the influence of an electric field

2010 ◽  
Vol 8 (1) ◽  
pp. 41-50 ◽  
Author(s):  
Barbara Stopa ◽  
Barbara Piekarska ◽  
Leszek Konieczny ◽  
Marcin Król ◽  
Janina Rybarska ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Electric Field ◽  
Congo Red ◽  
Polarized Light ◽  
Sodium Dithionite ◽  
Ordered Structure ◽  
X Ray Diffraction ◽  
X Ray ◽  
Protein Molecules ◽  
Ordered State

AbstractThis study describes a technique which makes it possible to introduce the amyloid-like order to protein aggregates by using the scaffolding framework built from supramolecular, fibrillar Congo red structures arranged in an electric field. The electric field was used not only to obtain a uniform orientation of the charged dye fibrils, but also to make the fibrils long, compact and rigid due to the delocalization of pi electrons, which favors ring stacking and, as a consequence, results in an increased tendency to self-assemble. The protein molecules (immunoglobulin L chain lambda, ferritin) attached to this easily adsorbing dye framework assume its ordered structure. The complex precipitating as plate-like fragments shows birefringence in polarized light. The parallel organization of fibrils can be observed with an electron microscope. The dye framework may be removed via reduction with sodium dithionite, leaving the aggregated protein molecules in the ordered state, as confirmed by X-ray diffraction studies.

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