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Flashcards in 7/12 Deck (55)
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what is Kinesin

a microtubule motor protein that provides anterograde (away from nucleus to the axon) transport of NT-vesicles towards synaptic terminals


what is the most common hepatic malignancy

metastatic from another primary site

HCC can present multi focally, univocally, or as diffusely infiltratively. It's more common in a pt w/ h/o cirrhosis or Hep B/C


what is cryptogenic stroke frequently associated with

Patent foramen ovale and atrial septal defect


how does a PFO close

after delivery, umbilical cord is clamped and there's decreased pulmonary vascular resistance, which lowers RA pressure and raises LA pressure.

This pushes the septum premium against the septum secundum, closing the foramen ovale


differentiate between ASD and PFO

results from APLASIA of septum primum or septum secundum during development;
may lead to embolism, but much less common than PFO

more common
incomplete FUSION of atrial septum premium and secundum


what will exztraperitoneal structures have layered on top of them

skin, fascia, abdominal muscle layers, anterior abdominal aponeurosis

(no peritoneum)


what are 2 antiretroviral therapy drugs that do not require kinase activation

Cidofovir and Foscarnet

Both are viral DNA polymerase inhibitors

both particularly useful in CMV and acyclovir-resistant HSV


what is unique about tRNA

noncoding RNA that contains many chemically modified bases (ex dihydrouridine, ribothymidine)

contains a "CCA" sequence at its 3' end used as a recognition sequence by proteins

the 3' terminal -OH on the CCA tail serves as the amino acid binding site, ensuring correct tRNA recognition by the proper aminoacyl tRNA synthetase


what are the tRNA secondary structure regions

acceptor stem:
base-pairing of the 3' CCA + OH tail and 5' nucleotides

D loop:
dihydrouridine residues that also help facilitate correct tRNA recognition by aminoacyl tRNA synthetase

Anticodon loop:
contains sequences complementary to the mRNA codon.
Ribosome complexes select the proper tRNA based solely on anticodon sequence.

T loop:
contains "TgreekYC" sequence necessary for binding of tRNA to ribosomes


what is Riboflavin a precursor for, and what enzyme is inhibited in defiancy

Vit B2 is a precursor for coenzymes FMN and FAD.

FAD participates in the TCA cycle with succinate dehydrogenase,
which converts succinate to fumarate

FAD and FAM are derived from riboFlavin
(B2 = 2 ATP)

deficiency = the 2 C's of B2:
Corneal vascularization


what does an elevated serum ACE level suggest



what is hyper acute rejection

type 2 hypersensitivity

Pre-existing antibodies react to donor antigen and activate complement.
Examples incl anti-ABO and anti-HLA antibodies

causes immediate (min-hrs) thrombosis, ischemia, and necrosis


what is acute organ rejection

cell mediated
usually weeks-months

exposure to donor antigens induces humoral and cellular activation of NAIVE immune cells

has a cellular and a humoral component

causes vasculitis with dense interstitial lymphocytic infiltrate.
prevent/reverse with immunosuppressants.


what is the cellular component of acute organ rejection

lymphocytic interstitial infiltrate and endotheliitis. These are CD8+ T cells activated against donor MHCs, which is Type 4 hypersensitivity rxn.


what is the humoral component of acute organ rejection

similar to hyper acute (recipient antibodies react to donor antigens), except the antibodies develop after the transplant.
There's C4d deposition, neutrophilic infiltrate, and necrotizing vasculitis


what is the difference between a manic and a hypomanic episode

severe symptoms
>1 week unless hospitalized
marked impairment in functioning!
may have psychotic features, which would make it automatically manic

less severe
>4 consecutive days
change from baseline, but not severe enough to cause marked impairment or necessitate hospitalization
NO psychotic features


what is viral reassortment

when viruses with segmented genomes (BOAR) exchange genetic material.

For example, novel H1N1 pandemic emerged via reassortment of human, swine, and avian virus genes.

Has potential to cause antigenic shift, and highly mutagenic viruses (influenza, ex)

reaSSortment = Segmented = Species = Shift


what is viral recombination

exchange of 2 genes between2 chromosomes by CROSSING OVER within region of significant homology. The progeny have gene traits from both parents.

reCombination = Crossing over


what is phenotypic mixing

when a host cell is simultaneously infected with 2 viruses.

Virus A's genome can be covered by Virus B's surface proteins.
This means Virus B's coat determines the tropism (infectivity) of the hybrid virus.

However, the progeny of this infection will have Virus A's coat, since Virus A is the one donating the genetic material.


what is transformation

the uptake of (viral) DNA and incorporation into host cell chromosomes (lysogeny)

this alters the genetic composition of host cell but typically causes no genomic changes in progeny virions


what is pancreas divisum

ventral and dorsal parts fail to fuse at 8 weeks

the pancreatic ductal systems remain separate, with the accessory duct draining the majority of the pancreas


what is annular pancreas

ventral pancreatic bud abnormally encircles 2nd part of duodenum, forms a ring, and may cause duodenal narrowing and bilious vomiting


where does the spleen arise

mesentery of stomach. it's mesodermal
it has foregut blood supply


what forms the majority of pancreatic tissue

dorsal pancreatic bud

it forms body, tail, and most of head


what does the ventral pancreatic bud form

ventral pancreatic bud is the precursor of the uncinate process, inferior/posterior portion of the head, and major pancreatic duct


when is K+ permeability highest in an action potential

during repolarization phase
(not hyper polarization)


what is adenosine's MOA

reduces rate of spontaneous depolarization in cardiac pacemaker cells.

interacts with A1 receptors to activate K channels and inhibit L-type Ca channels. this prolongs phase 4 and slows the sinus rate and AV nodal conduction delay


what are rheumatoid arthritis antibodies

Rheumatoid factor,
which is and IgM auto-antibody against Fc component of IgG

also anti-citrullinated protein antibodies


which joints are spared in rheumatoid arthritis

DIP joints are spared

small joints (PIP, MCP, MTP) are affected


what antibodies are in CREST syndrome

anti-centromere antibodies