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Flashcards in usmle2: block4 Deck (75):
1

HIV protease inhibitors

specifically cleave gag (p24) and pol (enzymes) gene products into functional pieces

2

VHL

1. hemangioblastoma
-cerebellum & retinal
2. renal cell carcinoma
3. pheochromocytoma

also cysts in kidney and pancreas

3

how does CO cause hypoxia

1. binds to heme w/ higher affinity than O2
2. shifts hemoglobin dissociation curve all the way to left (no longer sigmoidal)
-- doesn't release o2 anymore
3. impairs ETC

4

why does HbF have greater affinity for oxygen than HgA?

bc HbF doesn't bind to 2,3BPG

5

where does Cu2+ in wilson's disease deposit in eye (Kayser-Fleischer ring)

cornea: descement's membrane

6

how does wilson's disease present

30-40s,
hepatitis, splenomegaly, hemolytic anemia

basal gangia (lentiform nuc) damage: dystonia, tremor, dysarthria

kayser-fleisher ring

7

what is the main enzyme responsible for oxidative damage by neutrophils

NADPH oxidase, unique
converts O2 into superoxide
main task!

superoxide dismutase acts as either 1. scavenger for these free radicals, in all cells
2. or helps made H202, and w/ MPO, making bleach for further attacking

8

where is NADPH oxidase located

membrane protein of phagosome

9

aldehyde dehydrogenase

converts aldehyde into carboxylic acid
impt for alcohol metabolism.

blocked by disulfram

10

how does sclerosing adenosis present

usu as a density on mammogram / incidentally on biopsy

usu not a mass

11

most common causes of palpable nodular masses in breast

fibrocystic changes

usu poorly defined, diffuse increase in consistency throughout breast tissue

often multiple and painful, w. tenderness during premenstrual phase of cycle

12

presentation of mammary duct ectasia

ill-defined, palpable periareolar mass

may be confused w/ carcinoma

can have skin retraction and thick creamy or bloody nipple discharge

13

dermoepidermal junction aggregates of large cells that fuse w/ adjacent nests

atypical cells w/ irregular nuclear contours, hyperchromasia, round/spindle shaped

dysplastic nevus, which can evolve into melanoma

recall: nevus can be junctional, compound, or intradermal. malignant melanoma w/ pleomorphism

14

squamous cell carcinoma on histology

will have keratin pearls

15

basal cell carcinoma on histology

basaloid tumors either
1. budding from epidermis or
2. residing within the dermis w/ nuclear palisading & retraction artifact evident along periphery of cell nests

16

dysplastic nevus syndrome

chr 9p21
'familial melanoma'

17

dermatofibrosarcoma protuberans

fibroblasts in a cartwheel/storiform patteerm
&
supernumerary ring chromosomes

18

langerhans cell histiocytosis

prolfierative disorders of dendritic langerhans cells from monocytic lineage

presentation:
lytic bone lesion & skin rash in child
or
recurrent otitis media with a mass involving mastoid bone

cells = functionally immature, do not efficienctly stimulate primart T lymphocytes via antigen presentation

express S-100 (mesodermal origin)
Bierbeck granules = TENIS racket on eM

19

Bierbeck tennis racket granules on EM

langerhans cell histiocytosis

20

flumazenil

bind to & blocks GABAb at the benzodiazepine binding spot

21

exercise on LV:
HR
LV end-systolic vol
LV end-diastolic vol
LV end-diastolic pressure

-HR increases (less parasymph, more sympth
-LV end systolic decreases (more preload, less afterload
-LV end diastolic vol increases

LV end-diastolic pressure does not change
--> decrease in TPR counterbalanced by increased cardiac output

22

clinical signs of alcoholic cerebellar degeneration

degenerate cerebellar vermis and anterior cerebellar lobes

wide-based gait, truncal instability, ataxia, nystagmus, dysarthria

23

3 important DNA binding protein domains?

-leucine zippers (alpha helix)
-helix-loop-helix
-zinc finger motifs

24

leishmania transmission & histology

macrophage w/ amastigotes.
sandfly

kala-azar: spinking fever, hepatosplenomegaly, pancytopenia

25

starting products for pyrimidine synthesis

CO2 + glutamine + 2ATP
via carbamoyl phosphate synthetase II

26

where does purine / pyrimidine metabolism occur?

cytosol

27

peroxisomes play a role in... (3)

-lipid metabolism (beta oxidation)
-oxidative reactions
-purine catabolism

28

positive psoas sign suggests.. (2)

-psoas abscess
-appendicitis

29

quadratus lumborum

runs from 12th rib to iliac crest.
helps extend & laterally flex vertebral column
fixes 12th rib during inspiration

30

alcoholic cardiomyopathy

dilated cardiomyopathy

31

causes of dilated cardiomyopathy

i'm mad my pump failed

iatrogenic
medications (doxorubicin, danorubicin)
alcohol
drugs (cocaine)
myocarditis
pregnancy
familial

32

causes of restrictive cardiomyopathy

my pounding 'art seems held still

metastasis
pompe
amyloidosis
sarcoidosis
hemochromatosis
systemic sclerosis

33

cardio: eccentric hypertrophy vs. concentric

eccentric: added in series: dilated cardiomyopathy

concentric: added in parallel: hypertrophy

34

carbolfuschin staining

acid-fast staining
retained by mycolic acid

35

presentation of choriocarcinoma

trophoblasts with NO VILLI

weeks following..

-normal birth
-evacuation of mole
-following an abortion

can present w/ metastasis to lungs, vagina, brain, liver, or kidney at time of diagnosis

36

placenta accreta results from

abscence of decidual layer
placenta stuck to uterine myomatrium

immediate postpartum bleeding secondary to failed placental separation

37

benzoyl peroxide

oxidizes bacterial proteins
bacteriostatic against propionibacterium acnes

38

chlorhexadine

antiseptic used as skin / dental cleanser

39

acitretin, tretinoin,adapalene, tazarotene

retinoid medications, bind nuclear receptors

40

major risk factors for ischemic heart disease. greatest?

smoking
HTN
diabetes
dyslipidemia
history of coronary heart disease

greatest: smoking

41

how does smoking risk of ischemic heart disease (2)

1. promotes atherosclerosis
2. promotes platelet aggregation

have 2-3x risk of nonsmokers

42

alcohol on MI

2 standard servings per day, decreases risk of MI

excessive --> other heart problems: HTN, cardiomyopathy, MI

43

how does the vagus n. enter abdomen

w/ esophagus (T10)

44

how does the thoracic duct enter abdomen

w/ aorta, T12

via aortic hiatus (median arcuate ligament of diaphragm)

45

how does the IVC enter abdomen

T8, central tendon of diaphragm

46

why are nitrates first line for angina pectoris

decrease both preload and afterload
arterial / venous vasodilation

47

type 2 maturity onset diabetes of young (MODY)

mutation in glucokinase (liver & beta pancreatic cells)

even higher Km that it should, higher threshold

48

von gierke mutation

glucose 6-phosphatase
only in live (glycogenolysis and gluconeogenesis)

have hepatomegaly and renomegaly

49

fructose / lactose in von gierke

bad. can't be converted to glucose bc defect in gluconeogenesis.

50

deficiency in pompe

alpha 1,4 glucosidase
acid maltase
acid alpha glucosidase

51

prognosis of pompe

early clinical findings in heart
PAS+ granules in lysosomes

hypotonia, macroglossia, hypertrophic cardiomyopathy, VERY EARLY DEATH

52

pontine hemorrhage

often w/ HTN

pinpoint pupils, loss of horizontal gaze, quadriparesis, decerebrate posturing, rapidly evolving coma --> death

53

vasogenic edema

often via intracerebral neoplasm
disruption of blood brain barrier --> increased vascular permeability & plasma filtration into cerebral interstitium

vasogenic: fingers: white matter

54

cytotoxic edema

increased intracellular fluid WITHIN neurons, glial, endothelial cells. due to impaired Na+ / K+ pump

usu after ischemic insult

cytotoxic: white & grey matter

55

what type of cerebral causes an increased ICP: cytotoxic / vasogenic

VASOGENIC --> net gain of fluid in intracranial space

cytotoxic is a shift of fluid from extra/intracellular

56

how does an intracerebral neoplasm increase ICP?

vasogenic edema!
disrupts BBB

57

reiter's syndrome classic & extra symptoms

classic: arthritis, urethritis, conjunctivitis

also: cutaneous findings; keratoderma blenorrhagica & balanitis circinata)

58

HLA B27

reiter syndrome
psoriatic arthritis
ankylosing spondylitis
IBD

59

only structure in female genital tract w/ 2 epithlium types?

cervix:

ecto --> squamocolumnear junction --> endo

ectocervix:
-stratified non-keratinized (like vagina), protrudes into vagina

endocervical canal
between external os -> internal os
-simple columnar epithelium; mucus-secreting glands

squamocolumnar junction:
squamous abrupty converts to columnar endo

60

histology of uterus

lined by endometrium -->

EPITHELIAL lining that proliferates and degenerates
(stratum functionalis)

reserve tissue that regenerates stratum functionalis (stratum basalis)

61

histology of fallopian tubes

simple ciliated columnar epithlelium

62

histology of ovaries

covered externally by simple cuboidal epthelium that ruptures w/ each ovulation

63

most common cause of infectious meningitis in patients w. AIDS

cryptococcos neoformans

64

amphotericin B toxicity

NEPHROTOXIC
hypokalemia
hypomagnesmia
rental tubular acidosis

65

kaposi sarcoma vs. bacillary angiomatosis

kaposi: HHV-8
- lymphocytic infiltrate

bacillary angiomatosis: bartonella hensela
- neutrophilic infiltrate

66

small cell carcinoma secreting ADH causes

free water retention --> HYPONATREMIA to try to rid of water

67

squamous cell carcinoma paraneoplastic syndrome

PTHrP --> hypercalcemia

68

hypercalcemia + tumor, consider

humoral hypercalcemia of malignancy

(PTHrP-secreting paraneoplastic syndrome)

69

presentation of hypercalcemia

fatigue, mental status change, dehydration, nephrolithiasis

can cause polyuria, polydypsia, and dilute urine (like nephrogenic diabetes insipidus) bc impairs renal concentrating ability

70

short peptide medication that is an analog of carboxyl terminal of delta chain of fibrinogen

abcixamab, eptifibatide, tirofiban

71

eptifibatide

(like abcixamab)
GpIIbIIIa blocker (integrin)

binds to fibrinogen binding site

72

tirofiban

like abcixamab

GpIIbIIIa blocker (integrin)

73

ticlopidine / clopidergrel bind..

ADP-receptors
GPCRs

74

clopidergel activation requires

is a prodrug

must be activated by hepatic cytochrome P-450 enzyme system

*note intxn w/ P450 inhibitors etc

75

zero-order kinetic metabolism

rate of enzymatic rxn independent of concentration of substrate

constant AMOUNT of substrate converted to product over time