L9

Question 1

Hyalinosis?

Answer 1

*Defined as :Morphologic description of deposited intra or extracellular non-structured substance with various chemical composition, mainly proteins.
* homogenous acellular glassy
predominantly Pink to eosinophilic red appearance in H&E stained section.
*No concomitant inflammatory reaction.

Question 2

Extracellular hyalinosis?

Answer 2

• in connective tissues intracellular
Examples :
o Hyaline changes in leiomyomas
oHyaline changes in old scars
oHyaline arteriolosclerosis in renal vessels
oHyalinized glomeruli
oCorpora amylacea in the prostate in the elderly.
oOthers: amyloid , collagen,hypertension

Question 3

Cellular H or intra, Hyaline:

Answer 3

plasma cell (russel bodies)—Hepatocytes (mallory bodies(alcoholic hyaline))—Renal tubule cell(droplet of protein resorption)—Zenker degeneration (skeletal muscles)—Guarneri bodies.
——
seen as
• Zenker’s degeneration in rectus abdominalis muscle of typhoid fever.
• Mallory’s hyaline in hepatocytes in alcoholic liver cell injury.
• Nuclear or cytoplasmic hyaline inclusions in some viral infections.
• Russell’s bodies in plasma cells representing excessive immunoglobulins in chronic inflammation

Question 4

AMYLOIDOSIS?

Answer 4

-Definition: Is a condition associated with a number ofinherited and inflammatory disorders in which extracellular deposits of fibrillar proteins are responsible for tissue damage and functional compromise.
-Insoluble “deposited for life”.
-These abnormal insoluble fibrils are produced by the aggregation of misfolded proteins (which are soluble in their normal folded configuration).
-Its name come from starch like amylose due to presence of abundant charged sugar groups .

Question 5

Nature of amyloid ?

Answer 5

• 90% of the amyloid is a fibril protein.
• 10% is a glycoprotein-normally found in serum- called P component or amyloid P protein .

Question 6

Macrophages play an important role in
amyloidosis by?

Answer 6

proteolytic cleavage of the precursor proteins —>amyloid fibrils.

Question 7

Pathogenesis of amyloid deposition, Factors may contribute to the aggregation

Answer 7

1) The protein have a tendency to form aggregates of misfolded forms when its concentration reaches abnormally high levels.
2) If excretion of the protein is impaired (amyloidosis associated with long-term dialysis).
3) A mutation may give rise to a form of a protein that has a tendency to fold improperly and form aggregates (hereditary amyloidosis).
4) Limited proteolysis may generate a protein that forms amyloid fibrils (amyloidosis associated with Alzheimer disease).