Flashcards in 7/12 Deck (55)
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
FIXED SPLITTING OF S2
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
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
base-pairing of the 3' CCA + OH tail and 5' nucleotides
dihydrouridine residues that also help facilitate correct tRNA recognition by aminoacyl tRNA synthetase
contains sequences complementary to the mRNA codon.
Ribosome complexes select the proper tRNA based solely on anticodon sequence.
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:
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
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
>1 week unless hospitalized
marked impairment in functioning!
may have psychotic features, which would make it automatically manic
>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
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