Wed Aug 5 Flashcards
Describe the changes found in osteoporotic bone
Trabecular thinning, with fewer interconnections
Lamellar bone structure resembling a mosaic =
pagets disease
Unmineralized osteoid deposits on trabecular surfaces =
osteomalacia
Persistance of primary spongiosa in the medullary cavity =
osteopetrosis
Subperiosteal bone resorption and cystic degeneration =
hyperparathyroidism
HPV viral structure
DS DNA naked
two causes of PKU?
- phenyalanine hydroxylase deficiency
- cofactor deficiency (may be from deficiency of the enzyme needed to regenerate the cofactor)
What is the cofactor for phenylalaline hydroxylase?
BH4
What enzyme regenerates BH4 ?
Dihydropterin reductase
Phenylalaine is converted to ____ by phenylalaine hydroxylase?
tyrosine
tyrosine is converted to…
DOPA
what enzyme converts tyrosine to DOPA?
tyrosine hydroxylase
what is the cofactor for tyrosine hydroxylase?
BH4
A deficiency of dihydropterin reductase would result in decreased activity of which TWO enzymes?
phenylalaine hydroxylase, tyrosine hydroxylase
what will cytogenic studies of fragile X syndrome usually show?
A small gap on the long arm of the X chromosome (the area of increased repeats does not stain)
pathophys of fragile X?
Trinucleotide repeats of CGG in the FMR1 gene on the X chromosome
Clinical features of fragile X syndrome?
- intellectual disability
- macrocephaly
- long narrow face
- prominent forehead, jaw, chin and ears
- macroorchidism
inheritance of fragile X syndrome?
X linked
how does progesterone effect bile/the gallbladder?
- reduces bile acid secretion
- slows gallbladder emptying
pathophys of chronic kidney rejection?
-over several months to years, antibodies are created to the graft HLA or other antigens, and lead to progressive antibody mediated inflammation. Irreversible damage leads to the kidney to reduce in size, with obliterative vasclar wall thickening, tubular atrophy and interstitial fibrosis
A dense, interstitial mononuclear infiltrate corresponds to which type of organ rejection?
Acute - t cell mediated
pathophys of pyruvate kinase deficiency?
- the defective pyruvate kinase in RBCs means they cant convert PEP to pyruvate, which normally produces an ATP
- RBCs rely on glycolysis for energy, and thus the decreased ATP -> dysfunction
- > rigid RBCs, easily lysed -> extravascular hemolytic anemia
what will be seen on blood microscopy of someone with pyruvate kinase deficiency?
echinocytes (thorny projections)
inheritance of pyruvate kinase deficiency?
autosomal recessive
why may TCAs lead to arythmias and conduction defects?
they can block cardiac Na fast channels
why does C perfingrens present with crepitis?
it rapidbly metabolizes carbohydrates producing gas
other than gas gangrene, what illness can C perfringens cause?
late-onset food poisoning -> transient watery diarrhea
what repeats in huntingons disease?
CAG
neurotransmitter changes in huntingtons disease?
decreased Ach and Gaba in the caudate
what will be seen on neuroimaging of hungtingtons disease?
caudate atrophy with enlargment of the frontal horns of thewh lateral ventricles
which part of the brain is the first to be damaged in the setting of ischemia?
hippocampus (specifically the pyramidal neurons)
MOA of ethambutamol
inhibits arabinosyl transferase
what is streptomycin?
aminoglycoside
MOA of rifampin
inhibits DNA dependent RNA polymerase
isoniazid MOA
inhibits mycolic acid synthesis
is gonorrhea intracellular or extracellular?
intracellular