Cannibalism and amyloidosis
In the middle of last century. The world economy is entering a stage of its rapid development after World War II. Automotive and aircraft are on the rise, the era of high technology marks its beginning, mankind about to conquer space… scientists discovered in Papua New Guinea tribes who practices ritual cannibalism.
Gaydushek (1957) describes unknown disease, which locals called Kuru (trembling from cold). This disease causes almost the half of all deaths among a tribe ofPapua New Guinea. Natives of that tribe have practiced ritual cannibalism. Gaydushek found that infection takes place in Kuru consumption of human brains, rough guts and meat. The disease was hitting mostly women, children over 4 years of age and adults over 60 years. Studies show that the causes of cannibalism in Kuru disease are different from bacteria, virus and all known until in science infectious agents.
Perpetrators were identified as protein molecules, which by immunohistochemical and electron investigation cannot be differed from protein molecules in amyloidosis. They are called prions (infectious protein particles) and they are unique because of their potential to transmit disease to other organisms by food. The mechanism of propagation of prions in the infected organism destroys the basic tenet of biology at the time by which all living organisms need to use nucleic acids to reproduce. The rule for the direction of creation of life “DNA-RNA- the protein” is backwards. For this discovery, in 1976 Gaydushek received the Nobel Prize.
Cannibalism is common in nature: mothers (boar, doe, hamster) eat their small, a chicken starts pecking asses of other birds in the flock and not stop until they are gutted and not pulled out their intestines, the female spider eats the male after end of coitus…`
One century before the discovery of prion diseases, Virchow gives a new name of the bacon disease. This long-known disease is characterized by the fact that the organs are enlarged, pale, compaction and cease to function. They look like bacon and this is where the name of the disease came from. Virchow found the following: the cut surface of organs in this diseases are coloured in blue – violet when treated with lugol solution and dilute sulfuric acid. Similarly, the cut surface of potato is coloured in the same colour, if flooded with iodine (lugol solution). What a potato consist of? Starch is its main ingredient, as in many other vegetables. Potatoes are rich in this storage form of carbohydrates. How to be called a disease in which organs are similar to the accumulation of starch? The suffix “oid” means “similar”. The scientific name of the starch is amylon. Hence the name of the disease – amyloidosis.
In amyloidosis in the internal organs is found accumulation of large amounts of foreign for the organism protein that has special color properties. In routine (normal) microscope slide amyloid appears as pink homogeneous substance stored in the interstitsium between parenchymal cells. If you do Kongorot staining, this protein is stained in orange – red. With metylviolet and kresylviolet is stained in metachromatic pink-red and with tioflavin S fluoresces in yellow – green.
Organs in amyloidosis are expandable, compact, pale, cease to function. The reason for this is that amyloid is deposited in the intercellular space as a barrier between blood vessels and cells. Thus abnormal protein impedes the passage of oxygen and nutrients to the tissues. So the body’s cells die by starvation and suffocation. Deposition of amyloid in the spleen is an exception, because there are two forms of amyloid deposition: sago spleen, only with involvement of lymph follicles and lardaceous spleen – the final stage, when amyloid is deposited in white and red pulp. Kidney with amyloidosis is called “big white kidney”
How does a person get sick of amyloidosis?
Modern understanding is that amyloidosis is a complication of other diseases. Amyloidosis occurs in people who for years suffered from any chronic inflammatory disease or tumor. The main point in the diseases that lead to amyloidosis is the production of large amounts of proteins, which enter in the blood circulation. In one case they are produced by cancer cells, in other case they are produced by the liver due to chronic inflammation. Tissue destruction in these diseases is primary reason for entering large amounts of proteins in the bloodstream. Macrophages in tissues capture these redundant protein molecules and phagocytouse them. In 5-15% of cases, macrophages go “crazy” and instead of doing their job of cleaning the body, they decide to use waste as a construction material to build a new protein molecule – amyloid.
What is the relation between amyloidosis and cannibalism?
Cannibalism (anthropophagy) is a topic that is present as a reality in prion diseases and as a symbolism in amyloidosis. Like the natives ritual cannibalism, devouring in amyloidosis of the body is realized at least two planes. One is a long time self – destruction of the tissues of its own immune cells in chronic inflammatory diseases and tumor cells in certain types of cancer (multiple myeloma). The second act is implemented by the body’s macrophages that have phagocytosed (eaten) large amount of protein (normal or defective) and at one point “decided” to use them for building material.
Same as amyloidosis prion diseases transmitted through cannibalism have a long incubation period.
In both diseases, against the newly synthesized protein molecules there is no inflammatory and immune response, despite severe tissue damage.
When science identify the prion protein molecules, a great surprise was that they actually represent…amyloid fibrils.
Prion proteins are invariably transformed into amyloid.
Amyloid and prion protein molecules are extremely resistant to physical (heat, cold, drying), chemical (formalin) and enzyme (protease) effects.