test #22 4.12 Flashcards Preview

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Flashcards in test #22 4.12 Deck (133):
1

signs of hypothyroidism

fatigue, weight gain, constipation, SLOWED RELAXATION of deep tendon reflexes, dry coarse skin

2

most sensitive marker for diagnosis of hypothyroidism

serum TSH

(though, will not be elevated in patients w/ hypothyroidism due to TSH deficiency [central hypothyroidism]

3

valproate teratogeniticty

neural tube defects (1-3% risk)
valproate inhibits intestinal folic acid absorption

4

signs of duodenal atresia?

clinical hallmark: bilious vomiting w/o abdominal distension. usually noted on 1st day of life.

peristaltic waves may be visualized in abdomen & history of polyhydramnios due to failure of amniotic fluid reabsorption in distal instestine

often seen in down syndrome

5

death resulting from bilateral renal agenesis

death from pulmonary hypoplasia shortly after birth

6

ebstein's anomaly? cause?

atrialized right ventricle (downward displacement of tricuspid valve).

occurs when mom takes lithium early in pregnancy.

7

anaphylactic reaction to type O blood products in person w/ recurrent sinopulmonary and GI tract infections?

selective IgA deficiency.

anaphylaxis to IgA! make IgG against it. IgA = foreign

8

C1 esterase inhibitor deficiency

hereditary angioedema. rare. AUTOSOMAL DOMINANT. ace inhibitors are contraindicated.

C1 esterase inhibits nonspecific C1 fixation

9

delirium? causes?

delirium: 'waxing & waning' fluctuations in consciousness. acute, global memory impairment, visual hallucinations. 'altered sensorIUM'

reversible & commonly occurs in hospital setting

AEIOU TIPS:
alcohol, electrolyte imbalace, iatrogenic (i.e. meds), oxygen hypoxia, uremia. trauma, infxn, posion, seizure (post-ictal)

10

delirium vs. dementia

onset, consciousness, course, prognosis, memory

in delirium:
acute, impaired consciousness, fluctuating symptoms, reversible, GLOBAL memory loss.

in dementia:
gradual, intact consciousness, progressive decline, usu irreversible, remote memory SPARED.
(reversible, at least partially, with: NPH, vitamin b12 deficiency, hypothyroidism, neurosyphilis, HIV)

11

Reye's syndrome description and pathogenesis

hepatic failure and acute encephalopathy. associated w/ use of aspirin in patients 5-14 y/o.

pathogenesis: unknown; affected children have metabolic error sensitizing to toxic effect of salicylates. especially in virally-infected cells. causes mitochondrial dysfunction.

mechanism: aspirin metabolites decrease beta-oxidation by reversible inhibition of mitochondrial enzymes.

12

describe lab findings & histology in reye's

vomiting, hepatomegaly. jaundice = rare.

increased ALT, AST, ammonia, bilirubin, prolonged PT and PTT.

light microscope: microvesicular steatosis. NO necrosis or inflammation.

EM: swelling, decreased mitochondria, glycogen depletion.

13

do not give aspirin (salicylates) to kids under..

16 y/o (except if Kawasaki)

14

histology of viral hepatitis

apoptosis of hepatocytes, acinar necrosis, periportal mononuclear inflammatory infiltration

15

liver findings in patients w/ right-sided heart failure

centrilobular congestion

16

histology of primary biliary cirrhosis

bile duct destruction, periductal granulomatous inflammation, bile duct proliferation

17

respiratory epithelium with stratified squamous epithlium

response to chronic irritation: METAPLASIA.

adaptive: resistant to irritation than columnar cells.

HOWEVER: no cilia/goblet cells: no mucociliary clearance. can lead to dysplasia (low-grade atypical cells). risk factor for carcinoma (high-grade atypia).

REVERSIBLE, can resolve upon discontinuation of smoking.

18

renal response to markedly narrowed renal artery (i.e. stenosis)

compensatory RENIN secretion (juxtaglomerular apparatus)

eventually: juxtaglomerular apparatus undergoes hypertrophy & hyperplasia (to make more renin).

juxtaglomerular apparatus: JG cells and macula densa

juxtaglomerular cells: modified SMOOTH MUSCLE CELLS located in alls of afferent and efferent arterioles.

macula densa: tall, narrow cells in distal tubules. monitor osmolarity and volume of urine that passes into distal tubules. pass info to JG.

19

juxtaglomerular apparatus (2)

juxtaglomerular cells: modified smooth muscle cells in afferent & efferent arteriole. secrete RENIN.

macula densa: tall narrow cells in distal tubules, sense osmolarity & volume in tubules

20

noise-induced hearing loss?

trauma to sterociliated hair cells of organ of orti. >85dB. distortion / fracture of stereocilia due to shearing forces against tectorial membrane.

loose high frequency first (4000Hz)

21

frequency of speech

500-3000Hz

22

acoustic reflex?

dampens effects of prolonged loud noise by contracting stapedius & tensor tympani.

23

tensor tympani & stapedius

note. paralysis of mandibular CNV3 results in hypoacussis -- complete loss of tensor tympani tone = hard to hear (even though it normal fxn dampens sounds at other extreme).

loss of stapedius (CNVII) = hyPERacussis

24

cupula

lies at apex of cochlea. has cells that sense rotation.

25

enhance LVOT in HCM by.. (3)

decreases venous return (valsalva, standing suddenly).

decreasing afterload.

increasing contractility

26

referral bias

/ admission rate bias. when cases & controls differ due to admission / referral processes.

i.e. enroll patients from all over nation, but use hospitalized control subjects form local institution

27

detection bias

a risk factor itself may lead to extensive diagnostic investigation & increase probability that disease is identified.

i.e. detecting more cancer in smokers, but smokers have more imaging surveillance due to smoking status!

28

sampling bias

non-random sampling of population. lead to study population having characteristics different from target population.

severely ill patients are more likely to enroll in cancer trials -- so results may not be applicable to patients w/ less advanced cancer.

29

lightning-related complications (5 systems)

(1) cardiac: arrest, arrhythmia
(2) neurologic: perihperal n. damage, seizure, confusion, respiratory arrest, autonomic dysfxn.
(3) dermatologic: lichtenberg figures (pathognomonic of lighting strike)
(4) MSK: rhabdomyolysis, bone fracture, compartment syndrome
(5) cataractsery (late sequelae), ruptured tympanic membrane, curling ulcers.

30

erythematous cutaneous marks in a fern-leaf pattern & second degree burns..

lichtenberg figures -- LIGHTNING INJURY

31

why are deep tissue burns relatively rare post-lightning strike?

short duration of electrical contact & flashover effect: tendency of lightning to travel over skin surface and discharge on ground --> lichtenberg figures

32

how does lightining cause skeletal fracturs?

rapid heating of surrounding air, generating shock waves, can travel through body & cause mechanical trauma.

33

rules re: cardiac pressure

1. left > right
2. atria ~ 10mmHg max.
3. max pressure in right ventricle & pulmonary artery ~ 25mmHg.
4. max pressure in aorta & LV ~ systolic BP

34

normal pulmonary pressure at rest? pulmonary HTN at?

at rest: 10-14mmHg.
pumonary HTN > or equal to 25mmHg.

35

protein A. protein cell wall component (a single polypeptide chain)

1. staph aureus
2. binds to Fc region of IgG, causing epitope binding sites to face AWAY from bacteria. prevents complement fixation and phagocytosis

36

sounds from opening snap in mitral stenosis

abrupt halting of leaflet motion during mitral valve opening (due to fusion of mitral valve leaflets).

37

most common cause of mitral stenosis

prior rheumatic carditis

38

secretin S cells located...

duodenum. increase bicarb secretion from exocrine pancreas. stimulated by HCl in duodenum.

39

role of thyroglobulin peroxidase (3)

(1) oxidation of inorganic iodine
(2) formation of mono- and diiodotyrosine
(3) coupling that forms T3 and T4.

40

thyroglobulin

high molecular weight, glycosylated protein that is present within the thyroid follicle. TSH increases its gene transcription.

41

role of thyroglobulin

iodine is added to tyrosine residues on thyroglobulin & stored there until thyoid follicular cells engulf, cleave for use.

42

how does N. meningitidis get into the meningies

pharynx --> bloodstream --> choroid plexus ---> meninges

remember hematogenous bc of systemic signs (i.e. sepsis & characterestic petechial signs, waterhouse-friderichsen, etc)

43

how does haemophilus influenza get into the meninges?

pharynx --> lymphatics --> meninges

44

how can S. pneumonia get to meninges post0otitis media?

middle ear --> contiguous tissues --> meninges

45

how does s. pneumonia and TB from lungs get into meninges?

primary lung focus --> blood --> meninges

46

describe TB meningitis

chronic, characterized by monoctes & lymphocytes in CSF, primarily affecting BASAL meninges.

47

typical adenovirus presentation

pharyngoconjunctival fever.

acute, self-limited, febrile pharyngitis cough, nasal congestion, conjunctivitis, enlarged cervical nodes.

accounts for only 2-4% of acute viral illnesses in general population, but common in crowded quarters (barracks, camp)

48

calicivirus

Norwalk virus -- epidemic outbreaks of viral gastroenteritis

49

bronchiolitis in infants caused by

RSV (paramyxovirus)

50

arenavirus

lymphocytic choriomeningitis virus (LCV). febrile aseptic meningoencephalitis or milk systemic influenza-like illness in humans exposed to infected HAMSTERS or MICE. (not person-to-person)

51

transport of unconjugated bilirubin into hepatocytes?

transported of conjugated bilirubin out of hepatocytes?

indirect unconjugated bilirubin. PASSIVE. via organic anion transporting polypeptide (OATP).

secreted ACTIVE via an ATP-binding cassette protein MRP2.

(if impair MRP2, conjugated bilirubin can passively diffuse via basolateral OATP --> conjugated hyperbillirubinemia.

52

describe conjugated bilirubin.
unconjugated bilirubin.

water soluble, non-toxic, loosely bound to albumin. can be excreted in urine.

unconjugated bilirubin: insoluble in water at physiological pH, tightly complexed to albumin. cannot be excreted in urine.

53

which type of bilirubin can lead to jaundice?

BOTH unconjugated & conjugated (bilirubin glucuronides) can accumulate systemically and deposit in tissues --> jaundice.

54

what 5 things can cause jaundice. which type of bilirubin is at play?

1. excessive production of bilirubin
2. reduced hepatocyte uptake
3. impaired conjugation
4. decreased hepatocellular excretion
5. impaired bile flow (intrahepatic or extrahepatic)

first 3 --> unjconjugated.
last 2 ---> mostly conjugated

55

gilbert syndrome

mild; low activity in UDP glucoronyl transferase (like in babies).

mild increase in unconjugated bilirubin

see jaundice with stress & fasting. otherwise, clinically silent.

56

crigler-najar

ABSENT UDP-glucoronyl transferase. increased unconjugated bilirubin. die within a few years

rx: plasmaphoresis and phototherapy

57

dubin-johnson

defective secretion of conjugated bilirubin. black liver. conjugated hyperbillirubinemia.

benign, autosomal recessive.

58

rotor syndrome

mild defect in excretion of conjugated bilirubin. no black liver. conjugated hyperbillirubinemia.

59

haptoglobin

produced by liver. released via exocytosis. decreases in hemolysis bc bound by free hemoglobin & removed by RES (liver and spleen).

60

conjugated bilirubin in gut

converted into urobillinogen by gut bacteria. 80% further broken into sterobilin and pooped out.

20% reabsorbed. 80% of this back into hepatocytes. 20% urobilin in urine.

61

indirect billirubin =

unconjugated

62

direct billirubin =

conjugated

63

heme metabolism in RES (reticuloendothelial system)

heme ---> biliveridin (via heme oxygenase).

biliveridin ---> bilirubin

64

sNRPs

small nuclear ribonucleoproteins. bind pre-mRNA to form splicesosome.

65

southwestern blot

DNA-binding protein. probe w/ double stranded protein.

detects transcription factors, nucleases, etc

66

c-Jun & c-Fos

nuclear transcription factors that bind to DNA via leucine zipper motif.

proto-oncogenes

67

Ras

proto-oncogene that codes for membrane-bound G protein. activates leads to MAP kinase pathway.

68

S-100 protein

homodimeric calcium-binding protein (similar in structure to calmodulin). important for protein phosphorylation & cell growth & differentiation.

marker for cells of neural crest derivation (melanocytes & schwann cells) & langerhan cells & dendritic cells.

69

raloxifene

SERM: binds to estrogen receptors. exhibits tissue specific behavior that can mimic or antagonize natural estrogen.

AGONIST on bone, cardiovascular system, blood lipoproteins.

ANTAGONIST: on breast and uterus

helps reduce breast & endometrial cancer and osteoperosis.

70

oral medroxyprogesterone acetate

synthetic progesterone. reduces incidence of endometrial hyperplasia.

long-acting contraception.

associated w/ decreased bone density

71

alendronate

bisphosphonate analogue of pyrophosphate. binds hydroxyapatite. stops osteoclasts.

72

tamoxifen

SERM

AGONIST: uterus & bone

ANTAGONIST: breast

good for rx: breast cancer incidence and osteoporosis.

BUT, associated w/ endometrial cancer.

73

clomiphene

SERM.

antagonist to ER in hypothalamus, blocks negative feedback to increase GnRH secretion (rx: infertility)

74

who determines pairing of tRNA and amino acid

each AA tRNA combo has own AA-tRNA synthetase to link them. some can proofread their tRNA.

error rate = VERY LOW.

75

sequence of amino acids in growing polypeptide chain determined by..

interaction between mRNA codon and tRNA codon. if wrong AA on tRNA, wrong AA will be in peptide (no amino acid proofreading during translation).

76

causes of sensorineural hearing loss

meniere's disease, acoustic neuroma, presbycusis, ototoxic drugs

involving inner ear, cochlea, or auditory nerve.

77

causes of conductive hearing loss

cerumen impaction, cholesteatoma, otosclerosis, external/middle ear tumor, tympanic membrane rupture, severe otitis media

obstruction of external sound vibrations to inner ear

78

what metabolism processes occur in mitochondria?

pyruvate carboxylation, TCA, beta-oxidation, ketogenesis.

part of heme metabolism, urea cycle, gluconeogenesis.

79

transketolase

enzyme in pentose phosphate pathway (HMP shunt).

uses B1 as cofactor

80

test for B1 (thiamine deficiency)

w/ transketolase

81

ornithine transcarbamoylase

converts ornithine + carbamoyl phosphate --> citrulline

82

succinate dehydrogenase

succinate --> fumarate. inner mitochondrial membrane protein & fxn in electron transport chain too.

83

3-hydroxy-3-methygutaryl-CoA lysase

HMG CoA lysase. mitochondrial enzyme, responsible for ketogenesis.

HMG CoA results from degradation of leucine & synthesis by HMG CoA synthase. also intermediate in formation of cholesterol.

84

name a thiazolidinedione. mechanism?

-glitazones.

reducing insulin resistance by binding to PPAR-gamma (peroxisome proliferator activated receptor gamma).

PPAR-gamma: transcriptional regulator of genes involved in glucose & lipid metabolism.

most important gene regulated by PPAR-gamma: adiponectin (cytokine secreted by fat tissue.

adiponectin levels low in type 2 diabetes. TZD increase adiponectin levels, which decrease insulin resistance.

85

adiponectin

levels low in type2 DM, leading to insulin resistance.

rx with thiazolidinediones increases adiponectin expression.

86

1st generation sulfonylureas? 2nd generation?

1st: tolbutamide, chlorpropamide

2nd: glyburide, glimepiride, glipizide

87

pramlintide

amylin analogs, decrease gastric emptying, decrease glucagon

88

exenatide & liraglutide

GLP-1 analogs; increase insulin and decrease glucagon

89

DPP-4 inhibitors: linagliptin, saxagliptin, sitagliptin

increase insulin, decrease glucagon release

90

glutamate is a precursor for.. (2)

GABA and glutathione

91

pheylalanine is a precursor for

tyrosine

92

tyrosine is a precursor for

thyroxine (T4), DOPA (-->melanin), dopamine, NE, E

93

cofactors in DOPA to NE synthesis

DOPA -> dopamine (B6).
dopamine -> NE (vit C).
NE -> E (SAM)

94

B6 is generally required for what reactions

(1) transamination
(2) decarboxylation
(3) glycogen phosphorylase

95

histidine is a precursor for

histamine

96

glycine is a precursor for..

porphyrin --> heme

97

tryptophan is a precursor for (2)

1. Niacin
2. 5-HT & melatonin

98

arginine is a precursor for.. (3)

creatinine, urea, and nitric oxide

99

rx for serotonin syndrome

cyproheptadine. first generation histamine antagonist w/ nonspecific 5-HT1 and 5-HT2 receptor antagonist properties.

100

flumazenil

antidote for benzo overdose

101

naloxone

antidote for narcotic overdose

102

mycobacteria cell wall

incorporate mycolic acid into the outer portion of peptidoglycan.

103

what anti-microbial agent is chemically similar to pyridoxine B6

isoniazid

104

first line against legionella

erythromycin

105

etiology of Hirschsprung's disease

failure of neural crests to migrate to the intestinal wall. rectum is always involved (travel caudally).

both submucosal (Meissner's) and myenteric (Auerbach)

appears NARROWED. proximal dilation bc of fecal retention

106

nitrate agent with highest bioavailabilty (~100%) if given orally?

isosorbide mononitrate (active metabolite of isosorbide dinitrate)

107

nitroprusside? rx?

only IV. used in hypertensive emergency. notable cyanide toxicity.

108

nitroglycerin

SUBLINGUAL. straight into systemic circulation (no first pass metabolism in liver)

109

examples of lower motor neuron diseases (2)

poliomyelitis and werdnig-hoffman (autosomal recessive)

110

rx for paroxysmal supraventricular tachycardia?

try valsalva & carotid massage to increase vagal tone to AV. if doesn't work, give adenosine.

increase K+ efflux, hyperpolarize and decrease Ca++ current

111

multiple rounded & polygonal cells w/ abundant clear cytoplasm

clear cell carcinoma (most common subtype of renal cell carcinoma)

112

presentation of renal cell carcinoma

triad of (1) hematuria (2) flank pain (3) palpable abdominal mass.

often have paraneoplastic (EPO, ACTH, PTHrP)

113

hematuria, flank pain, palpable abdominal mass & elevated hemtocrit

EPO producing RCC

114

metastatic brain cancer

metastasize within CNS, but rarely metastasize outside of CNS

115

smoking and cervical cancer?

smoking is an independent risk factor!

along w/ HPV, immunosuppresion, low socioeconomic status, sexual activity

not: diet, alcohol, family history

116

nicotinic receptor

2 binding sites for ACh. Na+ and Ca++ influx, K+ efflux

117

what happens to nonfunctional monoiodotyrosine and diiodotyrosine in thyroid

deiodination and iodine recycling

118

ADH signalling cascade

activates V2 receptors (GPCR). transposition of aquaporin 2 to luminal cell membrane.

119

water deprivation & vasopressin challenge.

1. deprive water. if urine does not concentrate in one hour ( 10% = central DI.

complete central DI = >50% change.

moderate change = partial central DI = some vasopressin present, but not enough to make kidney function

120

homer-wright rosettes

medulloblastoma

121

primative neuroectoderm tumor

medulloblastoma. 2nd most common posterior fossa tumor. DROP METS

122

3 prominent features of glioblastoma multiforme

1. white matter, cross midline
2. florid vascular prolif
3. pseudopalisading necrosis

123

ependymoma

roof of 4th ventrical. pseudorossettes with GFAP+ processes tapering towards blood vessels.

124

most common extracranial solid tumor in children

neuroblastoma. undifferentiated are small, blue, round cells. pathognomonic feature: neuritic process: neuropil. NSE, chromogranin, synaptophysin, S-100+. most important biological marker N-myc of chromosome 2

125

c-myc normal function

nuclear phosphoprotein that functions as TRANSCRIPTION ACTIVATOR controlling cell proliferation, differentiation, and apoptosis.

overexpressed in Burkitt's Lymphoma t(8,14)

126

fanconi anemia

mutation in DNA repair leading to anemia?

127

5 year survival for small cell carcinoma (even w/ treatment)

< 1 year. usu have distant mets by diagnosis.

128

pure red cell aplasia

rare form of marrow failure characterized by severe hypoplasia of marrow erythroid elements, in the setting of normal granulopoesis (WBC) and thrombopoiesis (platelets)

pathogenesis: inhibition of erythropoietic precursors & progenitors by IgG autoantibodies or cytotoxic T lymphocytes.

associated w/ thymoma or lymphocytic leukemia.

can also occur w/ parvovirus B19 infection (preferentially kills proerythroblasts).

129

all patients with pure red cell aplasia should undergo..

chest CT, to see if thymoma present. resection can cure disease.

130

MAJOR virulence factor of s. pneumonia

CAPSULE. without it, would not cause disease. has 82 diff capsules

131

quellung rxn

Ab against capsule causes capsular swelling in vitro

132

pneumolysin secreted by.. what does it do

s. pneumoniae. suppresses oxidative burst by phagocytes.

133

capsule generally are

anti-phagocytotic!