UWORLD 2

Question 1

patient with suspected lung cancer develops hiccups, shoulder pain, and dyspnea…affected nerve and vertebral origin?

Answer 1

phrenic
c3-c5

(c3,4,5 keeps diaphragm alive)

Question 2

histopathologic finding in HIV associated dementia

Answer 2

microglial nodules (groups of activated macrophages/microgilal cells formed aorund small areas of necrosis tha tmay fuse to for multinucleated giant cells

Question 3

gastric erosion vs ulcer

Answer 3

erosion - does not extend into MUSCULARIS MUCOSA (limited to mucosal layer)
ulcer - penetrate through the mucosal layer and extend into submucosal layer

Question 4

histologic feature of acute eczematous dermatitis (eczema)

Answer 4

spongiosis (due to accumulation of eema fluid i tne intracellular space of epidermis)

with chronic exposure, lesions bcome less edematous with thikcening of stratum spinosum and stratum corneum (acanthosis and hyperkeratosis respectively)

Question 5

what is the target of botulinum toxin

Answer 5

presynaptic exocytosis of ACh vesicles

Question 6

painless genital ulcers that progress into painful inguinal lmyphadenopatyh (buboes) and ulceration, mild fever and malaise…cells scrapings show cytoplasmic inclusion bodies

Answer 6

chlamydia trachomatis

Question 7

patient comes in with anemia but with normal WBC and platelet count and normal bone marrow…dx and associations

Answer 7

pure red cell aplasia (bone marrow failure of just pure erythroid elements) can be assocaited with inhibition of erythropoetic precursosrs by IgG autoantibodies or T lymphocytes associated with thymomas, lymphocytic leukemias and parvovirus b19

Question 8

nongonoccal urethritis, arthritis, conjunctivits

Answer 8

reactive arthritis
assoc with keratoderma blennorhagicum (hyperkeratotic vesicles on palms and soles) and sacroilitiis
HLAb27

Question 9

purpose of conjugating toxoid for Hib vaccine

Answer 9

since humoral immunity is immature in inffant younger than 2, conjugated toxoid induces T cell mediated immune response to help with formation of long term immunity via memory B cells

Question 10

What substance is specific to mast cells that is useful in diagnosing anaphylaxis?

Answer 10

mast cells release HISTAMINE AND TRYPTASE…

tryptase is useful is diagnosing anaphylaxis

Question 11

How do mast cells degranulate

Answer 11

aggregation of multiple IgE receptors brought together by multivalent antigen….this causes multiple IgE antibodies to become cross linked leading to degranulation

Question 12

two mechanisms of fibrates

Answer 12

upregulate lipoprotein lipase which will increase TG clearance and activate PPARa to induce HDL synthesis…
also blocks cholesterol 7 alpha hydroxylase which will stop synthesis of bile acids and decrease cholesterol solubility in bile = CHOLESTEROL STONES adverse effect

Question 13

difference between HLA class I and class II

Answer 13

class i - HLA A,B,C, expressed by all nucleated cells and prsesentendogenous to CD8
class 2 - HLA DP, DQ, DR

Question 14

perifollicular hemhorrhage, myalgia, subperiosteal hematoma, gingivitis

Answer 14

scurvy

Question 15

what two things need to be known before PCR

Answer 15

dNA template that includes target region to be amplified

olignonucleotide sequence of flanking regions must be known to make primers necesssary to start PCR

Question 16

receptor on T cells that binds to tumor cells which will DOWNREGULATE response of T cells against tumor cells

Answer 16

PD-1…similar to CTLA4
so tumors that overexpress these PD1 receptors can bypass T cell apoptosis and continue to grow…antibodies designed to block these receptors can help to kill these pesky tumor cells

Question 17

What does the lagging strand need more of that the leading strand does not?

Answer 17

increased DNA primase and ligase activity (making and glueing together alot more fragments)

Question 18

cardiomegaly, hypotonia, macroglossia, hepatomegaly, normal glucose, glycogen accumulation in lysozomes
dx and deficient enzyme

Answer 18

pompe

deficienct in a glucosidase

Question 19

recurrent vertigo, ear fullness/pain, unilateral hearing loss and tinnitus

Answer 19

meniere dx

due to incerased volume of endolymph in inner ear

Question 20

MOA IL-2’s anter cancer effects

Answer 20

IL 2 producd by helper T cells and stimulateds growth of CD4 and CD8 T cells and B cells…also activates natural killer cells and monocytes which helps kill metastatic melanoma and RCC

Question 21

elderly woman presents with SBO with hard mass in ileocecal valve

Answer 21

gallstone ileus (from gallstone that has moved into intestinal lumen through colecystoenteric fistula)
associated with air in biliary tree

Question 22

Mechanism of cystic fibrosis genetic defect

Answer 22

most COMMONLY due to 3 base pair deletion at CFTR F508 position…mutation will impair post translational processing of CFTR resulting in shunting of CFTR toward proteasome

Question 23

hemolytic anemia due to failure of glycoysis and rigid erythrcyte structure associated with what

Answer 23

increased extravascular hemolysis which will cause splenic hyperplasia in red pulp (increased removal of deformed erythrocytes)

Question 24

MOA nitrate

Answer 24

primary venodilator with modest effects on decreasing systemic vascular resistance

all to reduce preload via guanylate cyclase cGMP system

Question 25

dense fibrous deposits around tricuspid and pulmonary valves as well as moderate pulmonary valve stenosis WITH NORMAL LEFT HEART

Answer 25

metastatic carcinoid syndrome

associated with flushing, watery diarrhea, bronchospasm and elevated urine 5-hiaa

Question 26

histologic hallmark in neutrophils during leukomoid reaction

Answer 26

remember luekocyte alkaline phosphatase is normal or increased in leukomoid reaction….peripheral smear shoes Dohle bodies (blue basophilic periphearl granules in neutrophils)…also associated with increased bands, toxic grnaulation, cytoplasmic granules

Question 27

hereditary spherocytosis associated with increased risk of what GI complication

Answer 27

pigmented gallstones
NOT AUTOSPLENECTOMY (THAT'S SICKLE CELL)

Question 28

early MI, fibrinoid necrosis of arterioles, pericarditis, sterile valve vegetations on BOTH valvular surfaces, fibrino…wireloop changes and glomerular capillary basement membrane thickening

Answer 28

SLE

Question 29

holosystolic murmur best heard at apex, radiating to axilla….how to tell severity

Answer 29

presence of s3 gallop

(severe mitral regurg will manifest sound indicating volume overload with increased

Question 30

OD on something with garlic breath and profuse watery diarrhea…what is teh agent and antidote

Answer 30

arsenic

treat with dimercaprol and DMSA (succimer)

Question 31

absence of ganglion cells in distal colon and rectum

Answer 31

hisrshsprung

failure of neural crest migration

Question 32

how to dx hirschsprung

Answer 32

rectal SUCTION BIOPSY (because ganglion resides in submucosa and umuscular)