uWorld 7

Question 1

what is a distinct histopathologic manifestation of chronic hepatitis B

Answer 1

accumulation of HEPATITIS B SURFACE ANTIGEN within infected cytoplasm
appears as FINELY GRANULAR, HOMOGENOUS, DULL EOSINOPHILIC INCLUSION that fill the cytoplasm (ground glass hepatocytes)

hepatocyte necrosis (ballooning degeneration), apoptosis, steatosis, portal inflammation with mononuclear inclusions (lymphocytes, macrophages)

Question 2

what is seen in a liver infected with chronic hep C

Answer 2

lymphoid aggregates within portal tracts and focal areas of macrovesicular steatosis

Question 3

progesterone only pill and levonorgestrel intrauterine device prevent pregnancy how

Answer 3

thickening cervical mucus preventing sperm from accessing the uterus

Question 4

how do copper IUDs prevent pregnancy

Answer 4

copper ions elicit an inflammatory reaction in the uterus that is toxic to sperm and prevents fertilization

Question 5

anti-mitochondrial antibodies are seen in whom

Answer 5

primary biliary cirrhosis

Question 6

anti-centromere antibodies are found in whom

Answer 6

CREST syndrome

Question 7

what part of the sarcomere only has thick (myosin) filaments

Answer 7

H-band (portion of A band that straddles the M line- which looks like two white lines on EM)

Question 8

what part of the sarcomere is always the same length

what parts decrease in length during contraction

Answer 8

A band- corresponds to the thick filaments but includes where they overlap the thin (actin) filaments

H band and I band decrease in length during contraction

Question 9

what part of the sarcomere contains only thin filaments and what makes up the thin filaments

Answer 9

I band which contains the Z line (typically distinctly darker than the reminder of the sarcomere)
Z-line is anchor for thin filaments (actin, tropomyosin, troponin)

Question 10

what are the promoter sequences of eukaryotes

Answer 10

TATA (Hogness) box- 25 bp upstream for gene

CAAT box- 70 to 80 bp upstream of the gene

Question 11

Ehlers danlos is due to a what kind of problem

Answer 11

college synthesis- DEFICICENY in PROCOLLAGEN PEPTIDASE- enzyme that cleaves terminal N and C pro peptides from procallagen in the extacellulat space
collagen DOES NOT PROERPLY CROSSLINK

Question 12

how do corticosteroids (bethamethasone, dexamethasone) increase surfactant production

Answer 12

accelerating maturation of type II pneumocytes

Question 13

at risk pregnancies for preterm birth, antenatal administration of magnesium sulfate has been shown to decrease risk for what

Answer 13

cerebral palsy

Question 14

vesicles on the lips and hard palate with fever and lymphadenopathy is characteristic of what

Answer 14

gingivostomatitis (gums and hard palate are KEY)
(recurrent lesions are not as severe due to existing cellular and humoral immunity)

KEEP IN MIND: hand foot mouth is SOFT PALATE, buccal mucosa, tongue

Question 15

what is seen on Tzanc smear of HSV

Answer 15

multinucleate giant cells and intranuclear inclusion bodies

Question 16

dihydrorhodamine flow pyrometry testing revealing absence of the teen fluorescence that is characteristic of normal neutrophils is suggestive of what

Answer 16

Chronic Granulomatous Disease (NADPH oxidase deficiency)

X-linked mutation

Question 17

how do mu opioid receptors work

Answer 17

G protein-linked that activate secondary messenger pathways
POTASSIUM CONDUCTANCE is a major pathway- hyper polarizing postsynaptic neurons and termination of pain transmission
also can inhibit adenylate cyclase, calcium conductance, and transmitter release

Question 18

what is believed to be the primary causes of lacunar infarcts

Answer 18

lipohyalinosis and microatheromas (result form atherosclerotic accumulation of lipid-laden macrophages within the intimal later of penetration artery near its origin off the parent vessel)
these changes predispose to small-vessel occlusion and infra of the CNS with liquefactive necrosis

Question 19

what is a common side effect of thaiazolidinedione therapy (pioglitazone and rosiglitazone)

Answer 19

fluid retention with resultant weight gain and edema

can exacerbate underlying heart failure

Question 20

arterial puncture above the inguinal ligament (when trying to access the common femoral artery) increases risk for what

Answer 20

retroperitoneal hemorrhage (which cannot be controlled by manual compression and can lead to significant hemorrhage)

Question 21

bleeding into the pelvic cavity occurs due to what

Answer 21

pelvic trauma in men

trauma or gynecologic hemorrhage

Question 22

what is the right paracolic gutter and when does bleeding enter this space

Answer 22

space b/w ascending colon and abdominal was

pathology involving the GI organs (duodenum, gallbladder) causes fluid (bile, pus, blood) to accumulate here

Question 23

hemorrhage into thigh muscles would present how

Answer 23

significant pain and edema and possibly compartment syndrome

Question 24

what is responsible for the variation of bone mass in individuals

Answer 24

genetic factors

Question 25

pyrrolidonyl arylamidase (PYR) is positive for what organism

Answer 25

strep pyogenese

Question 26

what compensatory mechanism stops peripheral edema from occurring in COPD patients

Answer 26

increased tissue lymphatic drainage right HF increased central venous pressure, leading to rise in capillary hydrostatic pressure, net plasma filtration, and interstitial fluid pressure as interstitial fluid pressure increases SO DOES LYMPHATIC DRAINAGE, which can compensate for moderate CP elevations and prevent the development of clinically apparent edema

Question 27

clinically apparent edema only occurs when in for pulmonale

Answer 27

net plasma filtration has risen sufficiently to overwhelm the resorptive capacity of the tissue lymphatics

Question 28

pt with family history of sudden death shows up with QT prolongation, what other issue do they have

Answer 28

NEUROSENSORY DEAFNESS Jervell and Lange-Nielsen syndrome (AR)- which is a congenial QT-interval prolongation often from mutations of the genes coding for cardiac cell potassium or sodium channels

Question 29

pt with leukemia who recently underwent chemo and now has fungal respiratory infection with FEBRILE NEUTROPENIA (FN), typically defined as fever with absolute neutrophil could less than 500. fever chest pain, cough, dyspnea and hemoptysis in this setting suggests what fungus

Answer 29

Aspergillus (Invasive pulmonary Aspergillosis)

Question 30

people with profound and prolonged neutropenia are at especially high risk for viral and fungal infections, what are the two most common fungal infections found in this setting

Answer 30

Aspergillus and Candidia

Question 31

what is Becks triad and when is it seen

Answer 31

hypotension with pulses paradoxes, elevated jugular venous pressure, muffled heart sounds CARDIAC TAMPONADE

Question 32

what is the Hawthorne Effect

Answer 32

observer effect tendency of study subjects to change their behavior as a result of their awareness that they are being studied commonly seen in studies concerning behavioral outcomes or outcomes that can be influenced by behavioral changes

Question 33

what is berkson's bias

Answer 33

selection bias reacted by choosing hospitalized patients as the control gourd (they are sicker than normal its)

Question 34

what is the pygmalion effect

Answer 34

fact that the researchers believes in the efficacy of treatment can potentially affect outcome (teacher told certain randomly assigned students had high IQ, teachers have higher expectation for these kids, kids perform better- probably because teacher unconsciously behaved in a way that facilitated their success)

Question 35

what is seen in arginase deficiency

Answer 35

progressive development of spastic diplegia, abnormal movements, and growth delay in the setting of ELEVATED ARGININE DEFICIENCY arginase is a urea cycle enzyme that produces UREA and ORNITHINE from arginine Tx: LOW-PROTEIN DIET devoid of arginine MILD OR NO HYPERAMMONEMIA

Question 36

when is orotic acid overproduced

Answer 36

block in urea cycle leads to excess carbamoyl phosphate which is metabolized by dihydroorotate dehydrogenase to orotic acid found in citullinemia and ornithine transcarbomylase deficiency HYPERAMMONIA in boh disorders

Question 37

what are the three morphological variants of pneumonia

Answer 37

congestion (first 24 hours) red hepatization (days 2-3) gray hepatizaiton (days 4-6) resolution

Question 38

what is seen the congestion stage of pneumonia

Answer 38

first 24 hours affected lobe is red, heavy and body vascular dilatation, alveolar exudate contains mostly bacteria

Question 39

what is seen in the red hepatization stage of pneumonia

Answer 39

days 2-3 red, firm lobe (liver-like consistency) alveolar exudate contains erythrocytes, neutrophils, and fibrin

Question 40

what is seen in gray hepatizaiton stage of pneumonia

Answer 40

gray-brown firm lobe RBCs disintegrate alveolar exudate contains neutrophils and fibrin

Question 41

what is seen in the resolution stage of pneumonia

Answer 41

restoration of normal architecture | enzymatic digestion of exudate

Question 42

what happens to reverse T3 (rT3) levels in a patina with hypothyroidism being administered exogenous T3

Answer 42

it would decrease (as would T4) since reverse T3 (rT3) is made from peripherally converted T4 and T4 is low in this from the hypothyroidism and further negative feedback on the system TSH is also decreased due to negative feedback

Question 43

what are the more common NNRTIs

Answer 43

nevi rapine and efavirenz do not require activation via intracellular phosphorylation ADR: hepatic failure indicated by flu-like symptoms, abdominal pain, fever; SJS and TENs

Question 44

what kind of drug is emtricitabine

Answer 44

nucleoside reverse transcriptase inhibitor (NRTI) like zidovudine, must be converted into their monophosphate forms by cellular kinase (thymidine kinase) before they can be converted to pharmacologically active triphosphate forms

Question 45

how does HBV cause hepatocellular carcinoma

Answer 45

integration of viral DNA into cellular genomes of the host is considered a trigger of neoplastic changes viral protein HBx activates synthesis of insulin-like growth factor II and receptors for insulin-like growth factor I, thereby stimulating cell proliferation HBV gene products suppress p53 tumor suppressor in host cells