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Renal tubular acidosis
Minimal change disease
Focal segmental glomerulosclerosis (NORD)
Rapidly progressive glomerulonephritis
IgA nephropathy (NORD)
Acute tubular necrosis
Renal papillary necrosis
Renal cortical necrosis
Chronic kidney disease
Polycystic kidney disease
Multicystic dysplastic kidney
Medullary cystic kidney disease
Medullary sponge kidney
Renal artery stenosis
Renal cell carcinoma
Nephroblastoma (Wilms tumor)
Posterior urethral valves
Hypospadias and epispadias
Lower urinary tract infection
Transitional cell carcinoma
Non-urothelial bladder cancers
Congenital renal disorders: Pathology review
Renal tubular defects: Pathology review
Renal tubular acidosis: Pathology review
Acid-base disturbances: Pathology review
Electrolyte disturbances: Pathology review
Renal failure: Pathology review
Nephrotic syndromes: Pathology review
Nephritic syndromes: Pathology review
Urinary incontinence: Pathology review
Urinary tract infections: Pathology review
Kidney stones: Pathology review
Renal and urinary tract masses: Pathology review
0 / 8 complete
0 / 4 complete
cardiomyopathy with p. 308
carpal tunnel syndrome p. 449
classification p. 218
kidney deposition in p. 597
multiple myeloma p. 431
with rheumatoid arthritis p. 466
amyloidosis p. 218
amyloidosis p. 218
amyloidosis in p. 218
Sam Gillespie, BSc
In amyloidosis, “amyloid” refers to starch-like, and it goes back to an observation made by the German scientist Rudolf Virchow, who saw mysterious deposits in the tissue that stained blue with iodine, just like plant starch.
As it turns out, amyloids are actually just proteins that take on an abnormal shape, which makes them stick together and settle in tissues.
And amyloidosis is the name for the disease that develops as a result of the tissue damage from these protein deposits.
Normally, our cells produce thousands of proteins each and every moment, and these proteins need to fold into a particular shape in order to do their jobs properly.
If a protein folds incorrectly, it’s normally spotted right away and destroyed by proteases, which are enzymes that chop up larger proteins into tiny bits.
In amyloidosis, there are a few different ways that protein folding can go wrong.
One way is when normal proteins are produced in enormous amounts, and just a small fraction of them fold incorrectly.
A second option is that abnormal proteins with incorrect amino acid sequences are produced in normal amounts, and they fold incorrectly.
Either way, the misfolded proteins, called amyloids start to build up.
Sometimes there’s simply too many of them for the protease to handle, and other times, the way that they’re folded makes them tough to break down - a bit like a pistachio that doesn’t have an opening for your fingers to work with. Nightmare.
When the amyloid proteins get excreted out of the cell, they tend to clump together forming a rigid, insoluble structure called a β-sheet - like a folded sheet of paper.
These β- sheets then deposit in the extracellular space of tissues and cause damage.
So amyloidosis is a process where there are extra protein deposits, and there are many different proteins and diseases that follow that same underlying process.
In general, amyloidosis can be systemic, meaning that those protein deposits occur in multiple organ systems, or it can be localized, meaning that they occur in one organ.
Until recently, systemic amyloidosis was further broken down into primary amyloidosis, which is where amyloidosis was thought to be the main problem, and secondary amyloidosis, which is where there was another known disease process that resulted in the protein deposits.
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