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
what is budosenide?
corticosteroid
ibuprofen MOA
reversibly inhibts COX1 and COX2
diclofenac MOA
reversibly inhibts COX1 and COX2
indomethacin MOA
reversibly inhibts COX1 and COX2
what occurs in the white pulp of the spleen?
-this is where antibody coated bacteria are filtered out and antibodies are made my B cells
what occurs in the red pulp of the spleen?
this is where old and bad red blood cells are destroyed
what are the four myeloproliferative disorders?
- chronid myeloid leukemia
- polycythemia vera
- essential thrombocythemia
- myelofibrosis
What cells are increased in CML
mature myeloid cells, especially basophils
what drives CML?
t(9:22) - BCR-ABL fusion protein
what mutation is associated with the myeloproliferative disorders, excluding CML?
JAK2 kinase mutation
what are the EPO levels in polycythemia vera?
decreased
what proliferates in essential thrombocythemia?
mature myeloid cells, especially platellets
what proliferates in myelofibrosis?
mature myeloid cells, especially megakaryocytes
how does myelofibrosis lead to bone marrow fibrosis?
megakaryocytes produce excess PDGF - >fibrosis
name 3 antioxidant enzymes that convert ROS to water?
- superoxide dismustase
- catalase
- glutathione peroxidase
what is bronchophony?
phenomenon where spoken words are heard more clearly/loudly over an area of alveolar consolidation
explain the phys as to how estrogen is protective of bone?
Estrogen induces the production of OPG by osteoblast and stromal cells, which is a decoy for the RANKL, thus decreasing RANKL that can bind rank and thus prevent osteoclast differentiation and survival. It also decreased the expression of RANK on osteoclasts.
Decreased estrogen after menopause results in what change in bone?
Increased RANKL and decreased OPG. Osteoclasts upregulate RANK. -> increased bone resorption
what do MS plaques look like histologically?
they are characterized by perivenular inflammatory infiltrates - made of autoreactive t lymphocytes and macrophages directed against myelin
Name 4 organisms that can cause diarhea with a small inoculum
Shigella
Camyplobacter jejuni
Entameba histolytica
Giardia
NAme 4 organisms that need a relatively high inoculum to cause diarrhea?
Vibrio
Salmonella
Clostridium perfringins
E coli
which cells produce CCK?
I cells of the duodenum
The thalamic ventral posterior lateral nucleus receives input from…
dorsal columns and spinothalamic tracts
the thalamic ventral posterior medial nucleus receives input from…
the trigeminal pathway
trisomy 13 =
patau syndrome
cimex lectularius =
bed bugs
pediculus humanus capitis =
head lice
what is teriparatide?
recombinant parathyroid hormone
Serum alkaline phosphatase levels correlate with…
osteoblast activity (secreted by osteoblasts)
why does H pylori lead to increased gastric acid secretion?
-they colonize the gastric antrum which decreases somatostatin production and increased gastrin formation leading to increased H
sirolimus MOA
inhibitrs mTOR which is part of the IL2 signalling pathway in t cells
how does the spleen appear in someone with portal hypertension?
It will have an apparent expansion of red pulp. This is because the blood gets backed up and can lead to congestion of teh spleen -> blood filled sinsu’s and cords
what proteins are defected in familial chylomicronemia syndrome (type I)?
- ApoCII
- LPL
what is elevated in familial chylomicronemia syndrome (type I)?
chylomicrons
what are the manifestations of familial chylomicronemia syndrome (type I)?
- acute pancreatitis
- lipemia retinitis
- skin xanthomas
- hepatosplenomegaly
what proteins are defected in familial hypercholesterinemia (type II)?
- LDL receptor
- ApoB 100
what is elevated in familial hypercholesterinemia (type II)?
LDL
what are the major manifestations of familial hypercholesterinemia (type II)?
- premature coronary artery disease
- corneal arcus
- tendon xanthomas
- xanthelasmas
what are the major protein defects in familial dysbetalipoproteinemia (type III)?
ApoE
what is elevated in familial dysbetalipoproteinemia (type III)?
chlyomicrons and VLDL
major manifestations of familial dysbetalipoproteinemia (type III)?
premature coronary artery disease/PVD
what is defective in familial hypertriglyceridemia (type IV)?
Apo A-V
what is elevated in familial hypertriglyceridemia (type IV)?
VLDL
major manifestation of familial hypertriglyceridemia (type IV)?
pancreatitis
function of apoB-48?
mediates chylomicron secretion into lymphatics from intestine
function of C-II?
binds LPL on peripheral tissue -> degrades triglycerides in chylomicron
‘cuts and cleaves’
apoB48 is found on which molecules?
chylomicrons and chylomicron remnants
CII and ApoE is provided by..
HDL
function of ApoE?
mediates remnant uptake by the liver
which is the only lipoprotein that does not have apoE?
LDL
which molecules have B-100?
VLDL, IDL, LDL
function of apo-B100?
binds with LDL causing endocytosis into peripheral cell
which molecules have Apo A-I?
HDL
function of ApoA-I
activates LCAT, which turns naiscent HDL into mature HDL
