A number of interesting experiments, designed to test the relationship between the condition of suppuration and the production of amyloid, have been made of late years.
Amyloid develops in various organs and tissues and is commonly associated with chronic phthisis, tubercular disease of bone and joints, and syphilis (congenital and acquired).
Amyloidosis-The accumulation of amyloid deposits in various organs and tissues in the body so that normal functioning is compromised.
Deposits of this protein, called beta amyloid, are associated with Alzheimer's disease in patients.
Evolution of the serum amyloid A (SAA) protein superfamily.
Further, fibrillar amyloid has been shown to poison neurones, at least in the laboratory.
If a healthy spinal cord be hung up in spirit for a matter of six months or more, a glassy substance develops within it quite like true amyloid.
Iodine gives usually a dark brown reaction, sometimes a deep blue; iodine and sulphuric acid almost always call forth an intense deep blue reaction; and methyl-violet usually a brilliant pink, quite resembling that of true amyloid.
It further resembles true amyloid in giving all its colour reactions.
Oddi does not regard it as the essential constituent of amyloid, chiefly because the colour reactions are forthcoming in the residuum after the substance has been removed, while the substance itself does not give these reactions.
Oddi in 1894 isolated from the amyloid liver a substance which Schmiedeberg had previously obtained from cartilage and named " chondroitinic-sulphuric acid " (Chondroitinschwefelsaure).
Quite likely the amyloid may be a combination of the substance with a proteid.
Some may be poisoned; the beta amyloid peptide is a strong suspect.
Some organs are subject to enlargement from deposition within them of a foreign substance (amyloid, fat, &c.).
The aggregates comprise the amyloid deposits in the diseased brain and give rise to the SAFs found in treated brain homogenates.
The composition of amyloid plaques has also been studied in great detail.
The diagnosis of amyloidosis is histological, ie proof of AA amyloid deposition in biopsy material.
The hallmark lesions of these diseases are vacuoles and plaques, which are small round formations consisting of deposits of a protein called amyloid.
The hyaline material, unlike the amyloid, does not give the metachromatic staining reactions with methyleneviolet or iodine.
The name "amyloid " was applied to it by Virchow on account of the blue reaction which it gives occasionally with iodine and sulphuric acid, resembling that given with vegetable cellulose.
The reaction with methylviolet, however, differs from that with true amyloid in being evanescent.
The vaccine has been shown to clear clumps of the protein beta amyloid in the brains of genetically engineered mice.
The wax-like or amyloid substance has a certain resemblance to the colloid, mucoid and hyaline.
These findings indicate that defects in the normal activities of astrocytes in clearing beta amyloid could lead to the formation of plaques.
These proteins include fibrinogen, serum amyloid A, caeruloplasmin, C-reactive protein, haptoglobin and several others.
This amyloid substance is slowly and imperfectly digested by pepsin - digestion being more complete with trypsin and by autolytic enzymes.
Thus Krawkow and Nowak, employing the frequent subcutaneous injection of the usual organisms of suppuration, have induced in the fowl the deposition within the tissues of a homogeneous substance giving the colour reactions of true amyloid.
What exactly is the role of beta amyloid in the disease?
When hardened in spirit, however, the greater part of this experimental amyloid in the fowl vanishes, and the reactions are not forthcoming.