amyloidosis

Question 1

Amyloidosis =

Answer 1

set of clinical disorders, caused by extracellular deposition of insoluble abnormal fibrils that injure the tissue and leads to a set of disorders

Question 2

protein misfolding what type? and its importance

Answer 2

Beta-pleated sheet chain is the unifying feature of amyloidosis, and forms the basis of Congo red reaction, fibrillar ultrastructure, resistance proteolytic digestion.

Amyloid = extracellular deposition of proteins, arranged in a beta-pleated sheet

most proteins in the body is in alpha-pleated sheet, the body cannot cope if it’s in the beta-pleated state

Question 3

Cause? Protein misfolding (formation of beta-pleated sheets) due to:

Answer 3

Intrinsic tendency to misfold (transthyretin protein)
Misfolding and aggregation at high concentration (ß2 microglobulin)
Point mutations (hereditary amyloidosis)

Question 4

types of calcification

Answer 4

dystrophic
metastatic
idopathic

Question 5

dystrophic calcification

Answer 5

Dystrophic calcification is associated with normal serum Ca2+ and phosphate levels. It can be either intracellular or extracellular, but is deposited on nonviable or degnerating/dying tissues. Some examples are areas of atherosclerosis, damaged valves, necrosis (coagulative, caseous, liquefactive) and leiomyomas (smooth muscle tumours). For instance, in Monckberg’s medial sclerosis, which is a form of dystrophic calcification, Ca2+ depositis are fonund in the muscular layer of arterial walls without obstructing the arterial lumen.

Question 6

metastatic calcification

Answer 6

Metastatic calcification is associated with elevated Ca2+ levels, and occurs in vital tissues. This includes kidneys (around the renal tubule and leading to renal failure), lungs (in the alveolar wall) and the stomach (fundic glands). Metastatic calcification can be caused by”
Increased PTH - due to hyperparathyrodism (see below)
Bone destruction - due to cancers like leukaemia, skeletal metastasis from breast cancer, and increased bone turnover in Paget’s disease
Vit D disorders - where there is an excess vitamin D, leading to sarcoidosis
Renal failure - leading to phosphate retention and stimulates the parathyroid gland, resulting in secondary hyperparathyroidism
Metastatic calcification calcium can be identified using a Von Kossa stain.

Question 7

explain what u know about duchenne and