test #28 4.19 Flashcards Preview

UWorld mixed > test #28 4.19 > Flashcards

Flashcards in test #28 4.19 Deck (133):
1

examples of delayed-type hypersensitivity reactions

(1) contact dermatitis
(2) granulomatous inflammation
(3) tuberculin skin test
(4) candida extract skin reaction

2

delayed-type HSR mediated by..

T-lymphocytes (not Ab or complement).

reaction takes 1-2 days, bc antigen taken up by dendritic cells, present to CD4+ cells on MHC II.

Th1 cells secrete IFN-gamma, recruit & stimulate macrophages --> monocytic infiltrate.

[also occurs when 'walling off' TV

3

increased WBC post-corticosteroids

falsely elevated. due to demargination (release from vascular walls) of cells

4

2 disorders of mast cells

urticaria pigmentosum. systemic mastocytosis

5

what two factors drive angiogenesis

VEGF and FGF
-vascular ENDOTHELIAL growth factor
- fibroblast growth factor

VEGF: angiogenesis in variety of tissues: normal, chronically inflammed, healing, neoplastic. increases endothelial cell motility and proliferation --> new capillaries.

FGF-2: made by many cells. significantly involved in (1) promotion of endothelial cell proliferation, migration, and differentiation. also: impt in (2) embryogenesis (stimulating angioblast production)

[FGF: angiogenesis, embryonic develoment, hematopoiesis, wound repair]

6

somatomedin C

IGF-1

synthesized by growth-hormone influenced hepatocytes. stimulate cell growth and multiplication.

7

barrier to angiogenesis

laminin in basement membranes

8

non-viral-dependent nucleotides analogues

cidofovir (activated by cellular kinase) & tenofovir

9

rx for thymidine kinase-deficient (acyclovir-resistant) varicella?

fosacarnet: (PYROPHOSPHATE analog viral DNA polymerase inhibitor)

cidofovir: broad spectrum NUCLEOTIDE. analogue of cytidine monophosphate (activated by CELLULAR kinase)

10

factitious disorder vs. malingering

both CONSCIOUSLY creates symptoms.

factitious: for 1' gain (sick role/medical attn)

malingering: for 2' gain (avoid work, compensation)

11

munchausen syndrome

chronic factitious disorder

12

conversion disorder

unconscious; somatic.

post-stressor.

sudden neurological symptoms (loss of sensory/motor) with NO physical evidence.

13

somatic disorder vs. factitious & malingering

somatic disorder syndromes (i.e. conversion, hypochondriaisis, somatization) are UNCONSCIOUS

factitious & malingering: CONSCIOUS

14

somatization disorder (vs. conversion disorder)

somatoform disorder, several symptoms

usu begins <30 y/o. impact social/occupation.

4 pain
2 GI
1 sexual
1 neuro

with no physical exam / imaging evidence

(differs from conversion, which has specific NEURO and POST-STRESSOR)

15

hypochondriasis

somatoform disorder

preoccupation/fear of having serious illness despite medical evaluation & assurance.

often, mistinterpretation of normal bodily symptoms (gas = colon cancer). associated w/ Dr. shopping

16

body dysmorphic disorder

think body is pathologically flawed, when in fact, it is not.

17

chromosome 3p deletion

VHL

18

von-Hippel Lindau

autosomal DOMINANT.

cerebellar hemangioblastomas, clear cell renal carcinoma, and pheochromocytoma.

RCC develops in 40% of patients.

tumor supressor

19

cerebellar hemangioblastoma, clear cell renal carcinoma, pheochromocytoma

VHL (tumor supressor chr. 3)

20

location of RB

chr. 13

(osteosarcoma and retinoblastoma)

21

location of NF-1

chr. 17

22

WT-1 location

chr. 11

23

location of chemoreceptor trigger zone (area postrema)

dorsal surface of medulla, caudal end of fourth ventricle.

24

adhesion molecules

integrin, cadherin, selectin, Ig superfamily members

25

laminins bind to

collagen, fibronectin, laminin in ECM

26

fibronectin

large glycoproteins produced by fibroblasts & some epithelial cells. binds to integrin, matrix collagen, glycosaminoglycans. mediations cell adhesion

27

heparan sulfate

proteoglycan component of ECM.

associated w/ reticular fibers and basal laminae. helps w/ endothelial cell attachment to BM.

does not bind to cell surface integrins.

28

hyaluronic acid

glucuronic-acid containing glycosaminoglycan in ECM.

contributes to water retention in ECM -> lubricant properties. viscous, gel-like consistency.

29

elastic fibers

core of elastin protein surrounded by fibrillin

30

keratan sulfate

galactose-containing glycosaminoglycan. role in maintaining type I collagen fibril organization in cornea.

31

aromatase deficiency

present early:
- mom virilization (androgens)

female:
- ambiguous/male genitalia
- primary amenorrhea & tall (no estrogen to fuse epiphyseal plate

male
- tall w/ osteoperosis

32

aromatase rxns (2)

androstenedione -> estrone
testosterone -> estrogen

33

aromatase deficiency vs. 21-b hydroxylase deficiency in girls

aromatase deficiency
- has mom virilization
- no hypotension w/ salt wasting & hyperkalemia

34

auscultation site determined by..

position closest to where sound waves reverberate. NOT at position of valve

35

glomerular splitting of basement membrane (2)

MPGN II and Alport syndrome

36

Alport syndrome

triad:
1. glomerulonephritis
2. sensorineural deafness
3. eye problems

mutation in alpha-side chain of collagen type IV.

thinning and splitting of basement membrane

X-linked dominant.

37

nasal mucosal ulcerations "saddle nose" w/ glomerulonephritis

granulomatosis w/ polyangiitis (wegner's)

38

HSP 4 signs

IgA / C3 deposits everywhere
1. palpable purpura
2. abdominal pain
3. arthralgia
usu self-limiting, but can get..
4. glomerulonephritis & end-stage renal failure

usu post-infectious

39

drugs w/ negative chronotropic effects

(1) b-blockers
(2) non-DHP calcium blockers
(3) digoxin (independent vagal effects)
(4) amiodarone
(5) sotalol (class III w/ b-blocking effects)
(6) cholinergic agonists

40

what cell type exerts master control over iron metabolism?

HEPCIDIN, made by liver parenchymal cells

41

fate of Fe2+ in GI system

absorbed via DMT-1 channel in duodenum, bind to intracellular FERRITIN..
(1) stay in enterocyte, and pass in stool when sloughed off
(2) exist basolaterally via FERROPORTIN -> bind to transferrin in blood -> taken up by cells via transferrin receptor

PATH determined by hepcidin!

42

hepcidin

acute phase reactant. binds to ferroportin in enterocytes & macrophages & degrades it.

BLOCKS release of Fe2+. prevents iron overload.

43

anemia of chronic disease

increased levels of hepcidin (from liver) down regulate ferroportin. trap Fe2+ in macrophages and enterocytes.

44

filtered load =

GFR x Px

45

excretion rate =

V x Ux

46

RPF estimated w/

PAH clearance -- fully cleared

47

GFR estimated w/

creatinine clearance (similar to inulin)

48

normal filtration fraction

20% (GFR/RPF)

49

when does glucose begin to appear in urine? when are glucose transporters maximally saturated?

- begin at 200mg/dL
- saturated at 375mg/dl

50

normal GFR

100ml/min
180L/day

51

when GFR is normal (100ml/min), large decreases in GFR, causes ___ in serum creatinine

small increases in serum creatinine

52

when GFR is very low (<60ml/min), small changes in GFR causes ___ in serum creatinine

LARGE increases in serum creatinine

53

serum creatinine can be normal after loss of how much GFR

even after 50% loss!

54

general rule of thumb with changes in GFR & serum creatinine

everytime GFR halves, serum creatinine doubles.

55

increase in cardiac output during exercise

5 L/min to 20 L/min

56

early in exercise, how is CO maintained?

increase BOTH HR and SV

57

late in exercise, how is CO maintained

increase only HR

(stroke volume maxes out)

58

pulse pressure is directly related to? inversely related to

PP = systolic - diastolic
directly related to CO
inversely related to arterial compliance

59

three sympathetic hemodynamic effects in exercise.

why does MAP only increase 2-40mmHg?

(1) increased CO
(2) venoconstriction to increase preload
(3) vasoconstriction to muscles not participating in exercise

only modest increase in MAP bc of MAJOR decrease in SVR due to...

local vasodilation in skeletal muscle (via adenosine, adenosine, K+, ATP, CO2, lactate)

in exercise, skeletal muscle can get 85% of CO

60

infection of liver capsule w/ violin string adhesions of peritoneum to liver.

Fitz-Hugh-Curtis syndrome, resulting from PID

61

manifestation of pelvic inflammatory disease

endometritis, salpingitis, tubo-ovarian abscesses, pelvic peritonitis

can result in infertility

62

how does pregnancy increase risk of gallstones?

ESTROGEN: increase HMG-CoA reductase activity, bile = SUPERSATURATED w/ cholesterol

PROGESTERONE: reduce bile acid secretion, slow gall bladder emptying = HYPOMOTILE

together: ppt cholesterol crystals

63

staphylococcus bacteremia associated with..

intravascular devices

(i.e. indwelling central venous catheters)

64

in dehydration, fluid is primary reabsorbed by..

always PCT (~65% reabsorption), even in dehydration

(collecting ducts can take ~20% free water)

65

Fenoldopam

SELECTIVE D1 agonist.
vasodilate most ARTERIAL beds (esp coronary, renal, splanchnic, peripheral)

overall decreased SVR.

increased flow to kidney allows for Na+ and H20 excretion

ONLY drug to reduce BP while increasing blood flow to KIDNEY

66

rx for HTN emergency w/ concomittant renal insufficiency

fenoldopam

67

diazoxide

anti-HTN

K+ activator, relax smooth muscle --> ARTERIAL vasodilation

68

mechanism of hydralazine. must be given w/?

increase cGMP -> smooth muscle relaxation

arterioles > vein. afterload reduction

must give w/ beta-blocker, as it causes reflex increased contractility, HR, & fluid retention

69

first-line rx for HTN in pregnancy?

hydralazine (increase cGMP) with methyl-dopa (a2 agonist)

70

methyl-dopa

HTN in pregnancy. alpha-2 agonist

71

use of hydralazine & diazoxide

though arteriole vasodilator, often cause significant increase in HR and contractility & Na+ and fluid retention

72

nimodipine

DHP calcium channel blocker, used for post-subarachnoid hemorrhage (to prevent vasospasm)

73

nicardipine

DHP calcium channel blocker. vasodilates arterioles & myocardium.

can cause tachycardia

74

ways to get EHEC 0157:H7

- eating undercooked contaminted ground beef.
- person-to-person
- raw unpasterized milk
- swimming in / drinking sewage contaminated water

75

1st line disease modifying for rheumatoid arthritis?

methotrexate.

76

Leflunomide and TNF-alpha inhibitors for rheumatoid arthritis

also disease modifying agents, can use in combo w/ methotrextate

leuflunomide -- decreases pyrimidine synthesis

77

methotrexate side effects

stomatitis (painful mouth ulcers) and hepatotoxicity (hepatitis, cirrhosis)

78

hydroxychloroquine

unclear mechanism. accumulates in cell, and increases pH, reducing fxn.

antimalarial and used in SLE

79

impt side effect of hydroxychloroquine

RETINAL DAMAGE

80

formula for volume of distribution

amount of drug given (mg) / plasma concentration of drug (mg/L)

81

what causes a drug to stay in blood (low volume of distribution) (3)

large molecular weight
bound extensively to plasma proteins
highly charged
(~3-5L)

82

if drug has small molecular weight, but hydrophillic

will also distribute to interstitial space (~15L)

83

if drug has small molecular weight, and uncharged

can also cross cell membranes -- ~41 volume of distribution

84

Vd for drugs that are avidly bound in tissues?

higher than total body water (>40L)

85

G. lambia in stool

O&P (smear w/ iodine stain)

ellipsoidal cysts w/ smooth defined walls and 2+ nuclei

86

loperamide

opiate antimotility drug, can be used in traveller's diarrhea w/ no fever / blood in stool

87

rx for inflammatory traveler's diarrhea (stool w/ mucus & blood)

ciprofloxacin

88

rx for ancylostoma, ascaris, enterobius?

mebendazole

89

rx for tapeworms (cestode) echinococcus granulosa

albenzadole

90

mechanism of enfuvirtide

binds to gp41, blocks conformational change needed for fusion

91

side effects of nnrtis (nevirapine, efavirenz, delavirdine)

hepatic failure (first 6 wks). also steven-johnsons

92

propionyl-CoA made from catabolism of...

VOMIT
valine, odd-chain fatty acids, methionine, threonine, isoleucine, threonine

93

propionyl-CoA carboxylase deficiency

build up proprionyl-CoA

poor feeding, vomiting, hypotonia, lethargy, dehydration

exacerbated by VOMIT:
valine, odd chain fatty acids, methionine, isoleucine, threonine & cholesterol

94

L-asparaginase therapy

antineoplastic, gets rid of asparagine in serum (so rapidly dividing leukemic cells can't use it, as their synthesis of asparagine is impaired)

95

histidine metabolism

deaminated to urocanic acid, converted to N-forminino-glutamate (FIGlu). forimino group donated to THF to form glutamate and forminino-THF.

oxidative decarboxylation of histidine forms histamine --> released by mast cells in type I HSR

96

proline is a nonessential amino acid oxidized into..

glutamate

97

prognosis of minimal change disease

rapid response to corticosteroids

98

rx for all symptoms organophosphate poisioning?

pralidoxime (restore AchE)

atropine only stops muscarcinic effects, not nicotinic.

99

bronchi differences in chronic bronchitis due to smoking vs. asthma?

both have: thickening of bronchial epithelium, basement membrane, and bronchial walls, as well as edema, inflammatory infiltrates, submucosal mucous gland enlargement, and bronchial smooth muscle hypertrophy

smoking: patchy squamous metaplasia & neutrophil infiltrate

asthma: eosinophil / mast cell infiltrate

100

rupture of chordae tendineae can occur with..

endocarditis or MI

101

diseases that cause myocardial fibrosis

dermatomyositis, muscular dystrophy, carcoidosis, scleroderma

102

vegetations associated w/ bacterial endocarditis represent..

FIBRIN & PLATELET deposition at site of bacterial colonization.

often at site of endothelial damage

103

myxomatous degeneration of valve

often mitral valve in MVP.
in the setting of CT diseases, like Marfan's.

can predispose to endocarditis.

104

coarctation of aorta in infants pre-ductal pr post-ductal? cyanotic?

preductal. though there is right-to-left shunting, not enough to cause cyanosis.

105

5T's of congenital cyanotic diseases

(1) tetrology of fallot
(2) tricuspid atresia
(3) total anomalous pulmonary return
(4) truncus arteriosus
(5) transposition of the great vessels

106

what is tricuspid atresia?

congenital cyanotic heart disease.

one ventricle feeds both aorta & pulonary artery

107

pulmonary alveolar proteinosis (PAP) (presentation & histology)

presents: gradually worsening of dyspnea and productive cough

histology: bilateral patchy pulmonary opacification due to intraalveolar accumulation of protein & phospholipid (constituents of surfactant)

108

characterestic presentation of idiopathic pulmonary fibrosis

insidious-onset progressive exertional dyspnea, pulmonary function tests w/ restrictive profile

surgical biopsy: extensive interstitial fibrosis, paraseptal and subpleural cystic airspace enlargement (honeycomb lung)

109

restrictive pulmonary function test

FVC low
FEV1/FVC normal (>80%)

110

routes of hepatic abscess in US? in developing nations

1. portal vein
2. arterial supply
3. ascending biliary tract infection
4. direct invasion from adjacent source
5. penetrating injury

developing nations: parasitic infxn

111

most likely cause of hepatic abscess in US

hematogenous spread of staph aureus

112

valve abnormality in turner's

bicuspid

113

nonstenotic bicuspid aortic valve murmur

aortic ejection sound. early systolic, high frequency click over cardiac apex and/or right second interspace

114

most common cardiac abnormality in Turner's?

bicuspid aortic valve. can also have coarctation

115

calcitonin

decreases serum Ca2+ levels.

decreases bone resorption of Ca2+ by osteoclast inhibition, but not a dominant hormone

levels increase when given exogenous Ca2+

116

PTH regulates Ca2+ by.. (3)

(1) release from bone
(2) increased vitamin D to reabsorb more in gut
(3) increased renal absorption

117

vitamin D under control of..

high PTH mainly.

also low Ca2+ and low PO4-

118

when are calcitonin levels LOW?

when serum Ca2+ is low

119

xeroderma pigmentosum has mutation in what type of enzyme

UV-specific ENDOnuclease

(not EXOnuclease)

120

NADPH is required for..

fatty acid, cholesterol, and steroid synthesis

121

parinaud syndrome

paralysis of conjugate vertical gaze due to lesion in superior colliculi (i.e. pinealoma)

(pineal gland is anterior-superior to superior colliculi)

122

erythematous, papulovesicular, weeping, encrusted lesions that may evolve into thickened scaly plaques

eczematous dermatitis.

prone to bacterial superinfection -- yellow crust

5 types:
1. allergic contact dermatitis
2. atopic dermatitis
3. drug-related eczematous dermatitis
4. photo-eczematous dermatitis
5. primary irritant dermatitis

123

spongiosus

seen in exzematous dermatitis (i.e. contact dermatitis)

epidermal accumulation of edematous fluid in intercellular spaces.

intercellular bridges become distinctive. epidermis = spongy.

edema can become so marked --> intraepidermal vesicles by tearing desmosomes apart

124

acanthosis

increase in thickness of stratum SPINOSUM.

associated w/ psoriasis

125

dyskeratosis

abnormal, premature keratinization of individual keratinocytes. strongly eosinophilic and may have small basophilic nuclear remnant.

found in squamous cell carcinoma

126

hyperparakeratosis

retention of nuclei in stratum corneum (suggests incomplete keratinization)

normal on mucus membrane, but abnormal (actinic keratosis) in other areas

127

hypergranulosis

excessive granulation in stratum granulosum of epidermis. seen in lichen planus

128

lesser omentum

composed of hepatogastric and hepatodudenal ligament (along lesser curvature --> liver)

129

greater omentum

along grater curvature

130

adjustable gastric banding must pass through

lesser omentum, to enclose cardia

131

falciform ligament of liver

attaches liver to anterior body wall (contains ligamentum teres)

132

what ligament must be divided to have access to posterior stomach and anterior pancreas

gastrocolic ligament (connects greater curvature of stomach to transverse colon)

part of the greater omentum

133

what is contained in splenorenal ligament (2)

(2) splenic artery & vein
(3) tail of pancreas