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Flashcards in USMLE World 1 Deck (170):
1

relantionship between prevalence and PPV

Prevalence ∝ PPV/NPV

2

top cancers by incidence

1. breast/prostate; 2. lung; 3. colon

3

top cancers by prevalence

1. breast/prostate; 2. colon; 3. lung

4

respiratory epithelium

cilia is present all throughout; serous, mucous glands, goblet cells and cartilage dissappear

5

koilocytes

pyknotic superficial immature squamous cell with dense irregularly stainning cytoplasm and perinuclear clearing

6

osteocytes

gap junctions

7

elastase

protease secreted by alveolar macrophages

8

dynein

ATPase associated with microtubule doublets; retrograde transport and ciliary flagellar movement

9

type II pneumocytes

production of surfactant and regeneration of type I pneumocytes after injury

10

Brunner glands

only in duodenum

11

Peyer patches

mostly in ileum

12

histology of large intestine

goblet cells but no pits or villi

13

stratified epithelium of the respiratory tract

oropharynx, laryngopharynx, anterior epiglotis, true vocal cords

14

strep bovis endocarditis

associated with colon cancer 25% of cases

15

dextran adherence

viridans strep adheres to deposits of fibrin in damaged valves

16

congenital rubella

sensorineural deafness, cataracts and PDA

17

fulminant hepatitis

HEV. Not associated with chronic hepatitis.

18

HCV immuno resistance

antigen variability is responsible for lack of immune response; lacks 3'-5' proof reading activity

19

non sorbitol fermenter in McKonkey's

EHEC:0157

20

dyptheria vaccine (DPT)

antigen is beta subunit of diptheria endotoxin; active immunity IgGs

21

staph epidirmidis Rx

vancomycin

22

cryptococcus infection pathogenesis

asymptomatic infection of lungs --> meningitis; associated with pigeon droppings

23

toxoplasmosis MRI

ring-enhancing lessions

24

Hib vaccine

cell wall polysacchride conjugated with diptheria or tetanus toxoid

25

congenital toxoplasmosis

hydrocephalus, intracranial calcifications, chorioretinitis due to in-utero infection

26

n. meningitidis route of entry

nasopharynx --> blood --> choroid plexus

27

H. influenzae route of infection

pharynx --> lymphatics --> meninges

28

pneumococcus route of infection

middle ear --> meninges

29

viral UTI

adenovirus causes hemorrhagic cystitis

30

subcutaneous mycosis

sporothrix in gardners

31

interstitial pneumonia

CMV in AIDS patients; nuclear inclusion bodies; also atypical bugs: mycoplasma, RSV, chlamydia

32

legionella associations

water aerosols and humidifiers

33

catalase+ bugs

staph, pseudomonas, serratia, aspergillus, nocardia

34

cold aglutinins

IgM antibody formed against mycoplasma and EBV; reaction with RBCs results in anemia

35

types of aspergyllosis

invasive (neutropenic patients); colonizing (fungus ball); allergic (asthmatic patients)

36

epiglotitis

H. influenzae; sore throat, fever, drooling, airway obstruction, stridor

37

virulence factors of mycobacteria

sulfatides, tuberculin and serpentine cords

38

Legionaire's disease

high fever, pneumonia and diarrhea in a chronic smoker

39

clue cells

squamous epithelial cells covered by Gardnerella seen on wet mount

40

POMC

proopiomelanocorticotropin cleaved to yield ACTH, MSH and beta endorphin

41

opiod receptors

increase gK --> decrease pain

42

scotoma

visual field deficit surrounded by zones of normal vision indicates damage to macula in retina; retinitis pigmentosa, multiple sclerosis, diabetic nephropathy

43

reperfusion arrhythmia

caused by tPA, reteplase, tecteplase fibrinolytic therapy

44

osteoblast markers

LAP

45

osteoclast markers

acid phosphatase, urinary hydroxyproline

46

space constant

measure of the ability of an impulse to travel down an axon; low SC --> decrease impulse (ME)

47

bounding femoral pulse

water-hammer pulse in aortic insufficiency

48

pulsus parvus et tardus

aortic stenosis

49

blood transfusions

contain citrate which chelates calcium and results in hypocalcemic paresthesia

50

iron regulation

by epithelial cells of the gut and intracellular ferritin

51

law of conservation of masses

total flow = flow velocity * cross sectional area; flow in = flow out

52

AV shunt volume loop diagram

increased preload

53

conduction velocities of heart tissue

AV node (0.05m/sec); ventricular muscle (0,3m/sec); atrial muscle (1.1m/sec); purkinje (2.2m/sec)

54

source of ACE

lungs

55

RV/TLC in obstructive diasese

increased RV more than TLC

56

hypoxic vasoconstriction

as oxygen content decreases, arteriolar resistance increases

57

perfusion-limited

when substances equilibrate across the membrane

58

diffusion-limited

when substances do not equilibrate across membrane

59

diffusion of oxygen

perfusion limited

60

oxygen supplementation in COPD patients

COPD patients have chronic hypoxia and hypercapnia; hypoxia is main ventilatory drive so use O2 supplementation carefully

61

brown adipose

termogenin produces heat

62

pulmonary vascular resistance

increases as air is inhaled and on forced expiration due to increase tension of lung parenchyma

63

pathophysiology of pneumoconiosis

fine dust particles are phagocytosed but alveolar macrophages release growth factors that stimulate fibroblast proliferation and fibrosis

64

lung clearance mechanisms

large particles are trapped in upper respiratory tract; medium particles are cleared by mucocilliary transport; fine particles < 2.5um are phagocytosed

65

causes of decreased lung compliance

pulmonary edema, pulmonary fibrosis, decreased surfactant, pneumoconiosses, kyphoscoliosis

66

alveolar gas equation

PAO2 = 150 - (PaCO2/0.8); PaO2 is given value; use PAO2 to calculate A-a gradient: PAO2 - PaO2

67

hypoxemia in pulmonary embolism

due to Va/Q mismatch

68

Va/Q mismatch

increased A-a gradient

69

hypoventilation

hypoxemia with normal A-a gradient

70

causes of hypoxemia

hypoventilation, Va/Q mismatch, diffusion impairmnet, right-left shunt

71

lipid absorption and digestion

absorption --> jejunum; digestion --> duodenum

72

S4 heart sound

presystolic before S1; indicates decreased compliance of left ventricle

73

ASD murmur

wide fixed S2 splitting with increased pulmonic valve pressure

74

prevention of calcium stones

increase water intake and increase citrate which chelates calcium

75

pericardial tamponade

muffled distant heart sounds, hypotension, increased central venous pressure and jugular regurgitation; post MI complication results in decreased venous return and hypotension

76

cardiac hybernation

hypokalemia of heart muscle due to chronic ischemia in CAD; reversible with bypass revascularization

77

ischemic preconditioning

resistance to infarction by myocytes exposed to chronic ischemia

78

ventricular remodeling

adaptation in mass, volume and shape to compensate for increased hemodynamic load

79

chemical mediators of atheromas

PDGF and TxA2 by platelets

80

reperfusion injury

secondary to oxygen free radicals, mitochondrial damage and inflammation

81

billiary tract enzymes

gammaglutamyl transferase and alkaline phosphatase

82

liver function tests

PT, albumin, cholesterol

83

hepatic integrity enzymes

AST, ALT

84

alkaline phosphatase differentiation

if increased alkaline phosphatase, check gammaglutamyl transferase to differentiate LAP from liver AP

85

aromatase

converts androgens to estrogens; stimulated by FSH in granulosa cells; might be deficient in female pseudohermaphrodite or elevated in male pseudohermaphrodite; inhibited by anastrozole

86

cardiac contractility

depends on aerobic glycolysis to produce ATP and creatine phosphate; ischemia leads to loss of contractility in 30 seconds

87

paradoxycal thromboembolism

thrombus passes from veins to arteries through an ASD; ASD produces fixed splitting of S2

88

natriuretic peptide

synthesized by atria upon stretch and right ventricle (Brain natriuretic peptide BNP)

89

cyanosis improves with squatting

tetralogy of fallot; increased TPR/PVR ratio increases pulmonary flow

90

absence of edema in early CHF or cor pulmonale

because intrathroracic pressure becomes more negative (COPD, etc), venous return and lymphatic drainage increase

91

holosystolic murmur

mitral insufficiency, tricuspid insufficiency, VSD

92

S3 heart sound

left ventricle volume overload in CHF or mitral insuficiency

93

TGF beta

tumor suppressor, angiogenesis, fibroblasts

94

metalloproteinases

collagen degradation; released by macrophages; may result in rupture of atheroma and AMI

95

hemodynamic changes in aortic stenosis/left ventricular hypertrophy

acute atrial fibrillation --> hypotension --> pulmonary edema due to decreased preload and CO

96

cholestasis

leads to osteomalacia due to ADEK malabsorption

97

Wolf-Parkinson

pre-excitation due to accesory bundle of Kent; delta wave on ECG, decreased PR interval and widened QRS, treat with class Ia and III antiarrhythmics

98

isolated systolic hypertension

age related stiffening of the aorta

99

aortic stenosis

increased left ventricle to aorta pressure gradient

100

aortic insuficiency

palpitations due to increased stroke volume; head pounding due to high amplitude pulsations; "head bobbing" due to widened pulse pressure

101

mitral stenosis murmur

opening snap in early diastole after aortic component of S2 (immediately after closure of aortic valve) plus diastolic murmur

102

acute mitral insufficiency

due to rupture of cordae tendinae or prosthetic valve failure don’t have time for atrial adaptation; decreased compliance leads to pulmonary edema

103

mitral stenosis severity

S2-to-opening snap is short --> more severe

104

hepatic encephalopathy

decreased clearance of gut amonia by damaged liver --> increased GABA receptor activity

105

gynecomastia in cirrhosis

decreased estrogen metabolism by liver --> gynecomastia, palmar erythema, testicular atrophy, decreased body hair

106

sweat in cystic fibrosis Vs. normal people

normal --> hypotonic; CF --> hypertonic

107

uric acid stones

precipitate in acid collecting ducts; Rx alkalinization of urine + hydration + indomethacin/colchicine

108

squamous lung cancer paraneoplastic syndrome

PTH-like peptide

109

RANK receptors

mediate osteoclast differentiation; low estrogen upregulates RANK --> increased bone resorption --> less bone mass

110

why is H. pylory in duodenum

only colonizes gastric tissue; if present in duodenum it's due to metaplasia

111

cystic fibrosis secretions osmolarity

all isotonic except sweat which is hypertonic

112

infectious esophagitis

CMV (linear ulcerations), candida (pseudomembranes), HSV-1 vesicles/ulcers

113

pancreatic necrosis

intracellular activation of trypsin and all other proteolytic enzymes

114

osteoporosis risk factors

smoking, menopause, corticosteroid therapy, physical inactivity, caucassian, low BMI, alcohol

115

IL-5

associated with asthma; isotype switch to IgA

116

water deprivation test

increased urine osmolarity if primary polydipsia; no change in diabetes insipidus

117

triglycerides in insulin resistance

triglycerides and FFA increase insulin resistance in overweight individuals

118

somatostinoma

inhibits all GI hormones --> billiary stones due to decreased CCK and hyperglycemia due to decreased insulin

119

how does hyperprolactinemia result in osteoporosis

hyperprolactinemia --> hypogonadism --> decreased estrogen --> osteoporosis

120

bone changes in hyperparathyroidism

subperiosteal thinning

121

dexamethasone test

low dose suppress cortisol --> Cushing syndrome; high dose suppresses cortisol --> pituitary Cushing; no suppression --> ectopic ACTH

122

sex hormones in bone growth

sex hormones promote bone growth and epipheseal closure --> short stature in spite of growth spurt

123

hormonal changes with glucocorticoid therapy

decreased CRH, ACTH and cortisol

124

hormonal changes in cryptorchidia

affects seminiferous tubules and Sertoli cells --> decreased inhibin and increased FSH

125

hormonal changes in steroid therapy

increased testosterone, decreased LH and low sperm count

126

Lisch nodules

neurofibromatosis

127

Kayser-Fleischer rings

Wilson's

128

chromosome 8

c-myc

129

mitochondrial diseases

myoclonic epilepsy, Leber, MELAS

130

Friederich ataxia

progressive ataxia due to degeneration of spinocerebellar and dorsal column tracts, hypertrophic cardiomyopathy (50%), skeletal abnormalities, diabetes (10%), autosomal recessive

131

Lesch Nyhan

x-linked recessive deficiency of hypoxanthine guanine phosphorybosyl transferase (HGPRT)

132

heteroplasmy

mitochondrial inheritance shows phenotype depending on how many mitochondria patient has

133

Prader-Willi deletion

paternal 15q deletion but affected gene is from mother

134

genetic imprinting synonym

unisomal dysomy

135

HNPCRC mutation

DNA mismatch repair enzyme

136

Xeroderma mutation

DNA excision repair enzyme

137

methylation

silences genes

138

acetylation

activates genes; acetylation is on lysine residues

139

alpha-feto protein

increased in neural tube defects; decreased in Down's

140

Sturge-Weber

port-wine stains and angiomas on the face and ipsilateral arteriovenous malformation in the meninges

141

Osler-Weber-Rendu

hemorrhagic telangiectasia, recurrent epistaxis and GI bleeds

142

Tuberous sclerosis

autosomal dominant; mental retardation and seizures, angiofibromas, angiomyolipoma in the kidneys (80%); rhabdomyoma in the heart

143

probability that a person is a carrier if both parents are carriers

2 of 3

144

CFTR abnormality

impaired posttranslational processing with subsequent degradation

145

t(15,17)

translocation of retinoic acid receptors, no differentiation of myeloblasts

146

45XO karyotype

due to mitotic errors after fertilization

147

cystic hygroma Vs. brachial cyst

brachial cysts are uniloculated; hygroma has lymph tissue and are much larger (associated with Turner)

148

Kallman's syndrome

delayed puberty and anosmia, absence of GnRH; problem is in the hypothalamus

149

G6PDH deficiency hereditary pattern

x-linked recessive

150

22q deletion

DiGeorge

151

antinflammatory cytokines

IL-10 and TGF-beta

152

diabetic nephropathy drug of choice

ACE inhibitors and AT-1 blockers

153

blood findings in ACEi therapy

decreased angiotensin II --> decreased GFR --> increased serum creatinine

154

drugs that cause tubular necrosis

aminoglycosides, contrast agents, cisplatin, ampB, foscarnet

155

gold therapy

membranous nephropathy

156

determinants of volume of distribution

low volume of distribution: highly charged, bound to proteins, large molecular weight; large volume of distribution: drug is small and lipophylic

157

pathophysiology of angina

heart uses most energy from beta oxidation which consumes more oxygen per ATP produced than aerobic glycolisis; fatty acid synthesis inhibitors shift energy usage from b-oxidation to aerobic

158

edrophonium test

if symptoms improve --> myasthenia or myasthenia crisis (increase dose); if symptoms don’t improve --> cholinergic crisis (stop dose)

159

lithium toxicity

can be caused by NSAIDs and thiazides because they increase sodium and lithium reabsorption

160

on-off phenomenon

levodopa therapy; its unpredictable

161

low MAC

high potency

162

high solubility in blood

slow onset of action

163

Rx bronchiolitis

ribavirin

164

isoniazid side effects

vitamin B6 deficiency (sideroblastic anemia); ataxia, paresthesia, decreased pain sensation (peripheral neuropathy); hepatitis

165

glucocorticoid inhalant side effects

oral candidiasis (treat by washing mouth)

166

N-acetylcysteine

mucolytic used in CF; cleaves mucuous disulfide bonds

167

prophylaxis of meningitis

rifampin

168

bosentan

used for pulmonary hypertension; antagonist of endothelin receptors

169

Leber's optic neuropathy

mitochondrial inheritance; optic nerve degeneration; mutation arginine to histidine in ND4 gene affects subunit 4 of NADH dehydrogenase complex

170

myoclonic epilepsy with ragged fibers

mitochondrial inheritance; myoclonus, seizures, ataxia, mitochondrial myopathy; ragged look of mitochondria in muscle