uWorld 2 Flashcards

1
Q

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

A

MHC Class I
endogenous pathway of antigen presentation

found on surface of most nucleated cells of human body

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2
Q

integrins are necessary for what

A

binding of inflammatory cells to vascular walls during the process of TRANSMIGRATION through the endothelial layer from the bloodstream to the tissues

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3
Q

how does MHC class II antigen presentation happen

A

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

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4
Q

what is humoral hypercalcemia of malignancy (HHM)

A

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`

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5
Q

acute onset of mental status change is most suggestive of what (delirium, dementia, or depression)

A

delirium- a reversible, acute confusional state involving a reduced or fluctuating level of consciousness with difficulty sustaining attention and impaired memory and executive function

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6
Q

what is a brief psychotic disorder

A

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

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7
Q

what is type II (beta) error

A

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

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8
Q

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

A

design flaws (i.e. poor blinding, researcher expectancy)

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9
Q

what is Berkson’s Bias

A

election bias that van be created by selecting hospitalized patients as the control group (b/c they are less healthy than normal population)

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10
Q

what are Gardos channel blockers

A

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

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11
Q

what is the mechanism most likely responsible for the decreased genes expression seen in huntington disease

A
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
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12
Q

loss of hunting tin protein results in what

A

embryonic death

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13
Q

what causes a low volume of distribution (3-5 liters) of a drug (i.e. drug stays in plasma compartment)

A

large molecular weight
bound extensively to plasma proteins
highly charged (hydrophilic)

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14
Q

when would one see a volume of distribution of 14-16 liters

A

if the drug has a small molecular weight but is hydrophilic (charged)
(it can distribute into the plasma volume plus interstitial volume)

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15
Q

when does a drug exhibit a higher volume of distribution much higher than total body waster volume

A

drugs that avidly bind the tissues

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16
Q

how can thiamine deficiency be diagnosed

A

if baseline ERYTHROCYTE TRANSKETOLASE ACTIVITY is low but increases after thiamine pyrophosphate

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17
Q

what is the function of DNA polymerase delta

A

elongates Okazaki fragments of the lagging strand

fragments are later joined by the enzyme DNA ligase

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18
Q

snRNA is synthesized by what

A

RNA polymerase II (along with mRNA and miRNA)

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19
Q

what are anti-smith antibodies against

A

snRNPs (complexes of snRNA with proteins that are essential component of spliceosomes which remove introns from pre-mRNA forming m-RNA)

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20
Q

what is the first-line antidepressant for major depressive disorder

A

SSRI (block the serotonin transporter)

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21
Q

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?

A

power (power = 1-beta)

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22
Q

what is a type 1 error

A

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

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23
Q

what is seen microscopically in seborrheic keratosis

A

sells resembling basal cells, with variable pigmentation
hyperkeratosis (thickening of status corneum)

keratin containing cysts

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24
Q

what is discoid lupus erythematous (DLE)

A

thick, scaly, discoid plaque that erupt on unexposed skin and may result in scarring
systemic disease in not present in most patients with DLE

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25
Q

what is a xanthelasma

A

common yellowish macule, papule, or plaque found on the EYELID and is often associated with hyperlipidemia

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26
Q

what are most cases of Rett syndrome due to

A

de novo mutations in the X-linked MECP2 gene

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27
Q

what is seen in Rett syndrome

A
mainly girls
normal development to 5-18 months
loss of motor and language skills
development of stereotypical hand movements (wringing)
DECELERATION of HEAD GROWTH
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28
Q

what is the inheritance of Lesch-Nyhan syndrome

A

x-linked recessive

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29
Q

what is stereotypic movement disorder

A

characterized by stereotypical, purposeless motor behavior that begins in early development and is not better explained by another neurodevelopment or genetic disorder

30
Q

what is the functional residual capacity

A

point where the tendencies of the chest wall to expand and the lung to collapse oppose one another
creating an NEGATIVE INTRAPLEURAL PRESSURE of approx -5cm H2O
(during inspiration intrapleural pressure gets even more negative and thus induces a negative alveolar pressure drawing air into lungs)

31
Q

what is the most commonly featured bone

A

clavicle

32
Q

the clavical is the point of origin or insertion for what msucles

A
deltoid- inferolateral aspect
pectorals major- inferomedial aspect
subclavius- inferolateral aspect
sternohyoid- inferomedial aspect
trapezius- superolateral aspect
sternocleidomastoid- superomedial aspect
33
Q

the major and minor rhomboid muscles originate and insert where, what do they do

A

originate on the vertebral spines
insert on the medal border of the scapula
cause retraction of the scapulae

34
Q

serratus anterior muscle originates where and inserts where, what innervates it, what problem is caused by loss of innervation

A

originates- laterally on 1-8 ribs
inserts- meidal aspect of scapula
innervated by long thoracic nerve, injury causes winged scapula

35
Q

where does the sternoclavicular ligament attach and what does it do

A

attach the clavicle to the manubrium

hold medal side of medial fragment (of a fractured clavicle) in place

36
Q

where does the subclavius muscle originate and what is its function

A

originated on the first rib and inserts on the inferior lateral aspect of clavicle
functions to displace clavicle inferiorly

37
Q

where does the trapezius originate and insert

A

cervical spinous processes and insert on the lateral third of classical
pulls lateral fragment (of a fractured clavicle) superiorly but the combined traction from arm weight and pectorals major overcomes trap

38
Q

what causes superior displacement of medal fragment of the glacial following a fracture
what causes inferior displacement of the lateral fragment of the clavicle after a fracture

A

sternocleidomastoid- superior displacement

weight of the arm and pectorals major muscle cause inferior displacement

39
Q

what happens to EPO in COPD and why

A

erythropoietin production increased

smokers have chronic bronchitis (decreasing the diameter of conducting airways) and centrilobular emphysema (dilating the alveolar air places so that there is insufficient contact b/w the airspace’s and deoxygenated blood in alveolar capillaries) both which cause hypoxia
smoking can independently cause hypoxia by increasing concentration of carboxyhemoglobin
hypoxia is sensed by renal cortex that synthesize and release EPO

40
Q

in COPD what happens to expiratory flow rate, functional residual capacity,

A

Expiratory flow rate- decreased
FRC- increased
right ventricular afterload- increased
left ventricular compliance- not directly affected

41
Q

where do the ureters course anteriorly to the external iliac artery

A

at or just after the bifurcation of the common iliac artery
external iliac continues along the pelvic brim and passes under the inguinal ligament to become there femoral artery (it does not enter the true pelvis)

42
Q

where does the ureters cross anteriorly to the internal iliac artery

A

ureters gain access to the pelvis by crossing over the anterior surface of the common iliac artery near its bifurcation, at this point the ureter lies medial to the ovarian vessels and anterior to the internal iliac artery (WITHIN THE TRUE PELVIS)

43
Q

what crosses over the anterior surface of the ureter midway form the kidney to the pelvic inlet

A

gonadal artery and vein

44
Q

genes for extended spectrum beta lactamases (ESBL) are found where

A

PLASMIDS

45
Q

what is the treatment of choice for extended spectrum beta lactamase producing organisms

A

CARBAPENEMS

46
Q

porin mutations can confer resistance to what antibiotics and what organisms utilize this

A

penicillin and amino glycoside resistance

gram negative organisms (Pseudomonas)

47
Q

mutations in DNA gyrate can lead to resistance to what drugs

A

fluoroguinolones

48
Q

what is cryoprecipitate

A

contains only cold-soluble proteins (Factor 8, fibrinogen, cWF, vitronectin)

49
Q

what toxin from ETEC is like cholera toxin in striation and mode of action (explain)

A

LT (enterotoxin)

increases intracellular cAMP in gut mucosal cells by Gs

50
Q

endotoxin release induces an inflammatory response mediated by what

A

tumor necrosis factor-alpha and interleukin-1 secreted from activated macrophages

51
Q

when does one see “stacked brick” intestinal adhesion

A

enteroaggregative Escherichia coli (EAEC)
organisms adhere to jejunal, ill, and colonic mucosa in an aggregative, or stacked-brick, pattern and do not invade
implicated in persistant diarrhea in infants in developing countries

52
Q

the steric bud gives rise to what

A

collecting system of the kidneys (collecting tubules and ducts, major and minor calyces, renal pelvis, ureters

53
Q

the metanephric blastema gives rise to what

A

glomeruli, Bowman’s space, proximal tubules, loop of hence, distal convoluted tubule

54
Q

the structures of the mesonephros become what in males and females

A

males- Wolffian ducts (ductus deference and epididymis)

females- regresses and becomes vestigial Gartner’s ducts

55
Q

decompensated heart failure in the setting of a recent viral infection

A

DIALTED CARDIOMYOPATHY (dilated with abnormal systolic ventricular function)

56
Q

regional wall nation abnormality is suggestive of what

A

ischemic heart disease

causes volume overload resulting in eccentric hypertrophy

57
Q

glucagon works via what receptor

A

Gs

58
Q

what is the most common lung tumor and what does one see in it

A

hamartoma (pulmonary chondroma)
contain islands of mature HYALINE CARTILAGE, fat, smooth muscle, clefts lined by respiratory epithelium
presents as a “COIN LESION” with “POPCORN CALCIFICATIONS”

59
Q

what is the best description of thyroid peroxidase enzyme

A

thyroglobulin iodination
NOT thyroxine to triiodothyronine conversions b/c only 20% T3 comes from thyroid rest is converted by iodothyronine deiodinasefrom T4

60
Q

central lines are inserted how

A

in neck (internal jugular vein) or chest (subclavian vein) and is advanced until the catheter tip enters the SVC

61
Q

the SVC is derived from what

A

common cardinal veins

62
Q

what forms the descending aorta

A

fusion of the embryonic right and left dorsal aortas

63
Q

if a pt is started on meds and 10 days later they get joint pain and a pruritic skin rash that show fibrinoid necrosis and neutrophil infiltration what probably happened and what finding is seen in the pt

A
serum sickness (happens after administration of chimeric monoclonal antibodies or nonhuman immunoglobulins
decreased serum C3 level
64
Q

is leukocyte alkaline phosphatase is low

A

chronic myelogenous leukemia

65
Q

what are the findings of an accessory nipple

A

due to FAILURE OF INVOLUTION OF THE MAMMARY RIDGE

66
Q

what is an acrochorda

A

a skin tag
benign and often pedunculate outgrowths of notable skin
develop in locations of excess friction like beneath the breasts

67
Q

BRCA1 and BRCA2 are are involved in what and what is the inheritance

A

repair of double stranded DNA breaks

autosomal dominant

68
Q

what breast cancer mutation is associated with abarent signal transduction

A

HER2

69
Q

what organism looks “cotton candy” like on Pap smear and may be an incidental finding in patients with IUD

A

Actinomyces

70
Q

what cells predominate Pap smear of postmenopausal and postpartum women

A

paranasal cells- round cells with a basophilic cytoplasm, finely granular chromatin in their nuclei, no visible nuclei, high N/C ratio
“fried eggs” with a large “central egg yolk”

71
Q

what cell presence in a Pap smear indicated adequate sampling

A

glandular endocervical cells