uWorld 2 Flashcards
present self antigen, tumor antigen, or antigen synthesized by the cell due to viral infection
proteins in cytoplasm are degraded molecules and subsequently routed to the cell surface via the golgi apparatus
never processed w/in acidified lysosomes
MHC Class I
endogenous pathway of antigen presentation
found on surface of most nucleated cells of human body
integrins are necessary for what
binding of inflammatory cells to vascular walls during the process of TRANSMIGRATION through the endothelial layer from the bloodstream to the tissues
how does MHC class II antigen presentation happen
material in environment is taken up by APC and degraded by acidification after endosome-lysosome fusion or phagosome-lysosome fusion
MHC-II is synthesized in roughER and routed to endosomes by the Golgi apparatus
MHC-II is antigen binding site blocked by invariant chain- guides molecule during sorting and fusion of vesicle with MHC to phago-lysosome
what is humoral hypercalcemia of malignancy (HHM)
caused by secretion of parathyroid hormone related protein (PTH-rP)
causes increased bone resorption and decreased renal exertion of calcium
polyuria, nephrolithiasis, GI and neuropsychiatric symptoms`
acute onset of mental status change is most suggestive of what (delirium, dementia, or depression)
delirium- a reversible, acute confusional state involving a reduced or fluctuating level of consciousness with difficulty sustaining attention and impaired memory and executive function
what is a brief psychotic disorder
sudden onset of at least one positive psychotic symptoms (delusions, hallucinations, disorganized speech or behavior) lasting form one day to a month
typically alert and oriented
what is type II (beta) error
FALSELY conclude there was NO increased risk
probability of a type II error is related to how much POWER a study has to detect a difference when a difference actually exists (power = 1-beta)
SAMPLE SIZE and power are related in that studies with a large sample size have a greater power
if the RR obtained in the first study was similar to the one obtained in the meta-analysis it is unlikely what what was present in the study
design flaws (i.e. poor blinding, researcher expectancy)
what is Berkson’s Bias
election bias that van be created by selecting hospitalized patients as the control group (b/c they are less healthy than normal population)
what are Gardos channel blockers
calcium-dependent (Gardos) potassium channel regulators the transport of potassium and water through the red blood cell membrane- when blocked, potassium and water efflux if reduced, preventing dehydration of erythrocytes and reducing the polymerization of HbS
what is the mechanism most likely responsible for the decreased genes expression seen in huntington disease
HISTONE DEACETYLATION- thus silencing genes necessary for neuronal survival expansion of the huntingtin protein results in a GAIN-OF-FUNCTION that leads to pathological interaction with other proteins, including various transition factors TRANSCIPTIONAL REPRESSION (SILENCING) is one of the mechanisms by which mutated huntingtin is thought to cause disease
loss of hunting tin protein results in what
embryonic death
what causes a low volume of distribution (3-5 liters) of a drug (i.e. drug stays in plasma compartment)
large molecular weight
bound extensively to plasma proteins
highly charged (hydrophilic)
when would one see a volume of distribution of 14-16 liters
if the drug has a small molecular weight but is hydrophilic (charged)
(it can distribute into the plasma volume plus interstitial volume)
when does a drug exhibit a higher volume of distribution much higher than total body waster volume
drugs that avidly bind the tissues
how can thiamine deficiency be diagnosed
if baseline ERYTHROCYTE TRANSKETOLASE ACTIVITY is low but increases after thiamine pyrophosphate
what is the function of DNA polymerase delta
elongates Okazaki fragments of the lagging strand
fragments are later joined by the enzyme DNA ligase
snRNA is synthesized by what
RNA polymerase II (along with mRNA and miRNA)
what are anti-smith antibodies against
snRNPs (complexes of snRNA with proteins that are essential component of spliceosomes which remove introns from pre-mRNA forming m-RNA)
what is the first-line antidepressant for major depressive disorder
SSRI (block the serotonin transporter)
to ensure that that investigators do not miss a difference between drug B and standard of care (if a difference truly exists) what do you want to maximize?
power (power = 1-beta)
what is a type 1 error
reject the null hypothesis when the null hypothesis is really true (finding a statistical significance b/w 2 groups that doesn’t exist)
if p is less than a (0.05) then it is statistically significant
what is seen microscopically in seborrheic keratosis
sells resembling basal cells, with variable pigmentation
hyperkeratosis (thickening of status corneum)
keratin containing cysts
what is discoid lupus erythematous (DLE)
thick, scaly, discoid plaque that erupt on unexposed skin and may result in scarring
systemic disease in not present in most patients with DLE
what is a xanthelasma
common yellowish macule, papule, or plaque found on the EYELID and is often associated with hyperlipidemia
what are most cases of Rett syndrome due to
de novo mutations in the X-linked MECP2 gene
what is seen in Rett syndrome
mainly girls normal development to 5-18 months loss of motor and language skills development of stereotypical hand movements (wringing) DECELERATION of HEAD GROWTH
what is the inheritance of Lesch-Nyhan syndrome
x-linked recessive