test #22 4.12 Flashcards Preview

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Flashcards in test #22 4.12 Deck (133)
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1
Q
signs of hypothyroidism
A
fatigue, weight gain, constipation, SLOWED RELAXATION of deep tendon reflexes, dry coarse skin
2
Q
most sensitive marker for diagnosis of hypothyroidism
A
serum TSH

(though, will not be elevated in patients w/ hypothyroidism due to TSH deficiency [central hypothyroidism]
3
Q
valproate teratogeniticty
A
neural tube defects (1-3% risk)
valproate inhibits intestinal folic acid absorption
4
Q
signs of duodenal atresia?
A
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
Q
death resulting from bilateral renal agenesis
A
death from pulmonary hypoplasia shortly after birth
6
Q
ebstein's anomaly? cause?
A
atrialized right ventricle (downward displacement of tricuspid valve).

occurs when mom takes lithium early in pregnancy.
7
Q
anaphylactic reaction to type O blood products in person w/ recurrent sinopulmonary and GI tract infections?
A
selective IgA deficiency.

anaphylaxis to IgA! make IgG against it. IgA = foreign
8
Q
C1 esterase inhibitor deficiency
A
hereditary angioedema. rare. AUTOSOMAL DOMINANT. ace inhibitors are contraindicated.

C1 esterase inhibits nonspecific C1 fixation
9
Q
delirium? causes?
A
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
Q
delirium vs. dementia
A
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
Q
Reye's syndrome description and pathogenesis
A
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
Q
describe lab findings & histology in reye's
A
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
Q
do not give aspirin (salicylates) to kids under..
A
16 y/o (except if Kawasaki)
14
Q
histology of viral hepatitis
A
apoptosis of hepatocytes, acinar necrosis, periportal mononuclear inflammatory infiltration
15
Q
liver findings in patients w/ right-sided heart failure
A
centrilobular congestion
16
Q
histology of primary biliary cirrhosis
A
bile duct destruction, periductal granulomatous inflammation, bile duct proliferation
17
Q
respiratory epithelium with stratified squamous epithlium
A
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
Q
renal response to markedly narrowed renal artery (i.e. stenosis)
A
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
Q
juxtaglomerular apparatus (2)
A
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
Q
noise-induced hearing loss?
A
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
Q
frequency of speech
A
500-3000Hz
22
Q
acoustic reflex?
A
dampens effects of prolonged loud noise by contracting stapedius & tensor tympani.
23
Q
tensor tympani & stapedius
A
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
Q
cupula
A
lies at apex of cochlea. has cells that sense rotation.
25
Q
enhance LVOT in HCM by.. (3)
A
decreases venous return (valsalva, standing suddenly).

decreasing afterload.

increasing contractility
26
Q
referral bias
A
/ 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
Q
detection bias
A
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
Q
sampling bias
A
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
Q
lightning-related complications (5 systems)
A
(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
Q
erythematous cutaneous marks in a fern-leaf pattern & second degree burns..
A
lichtenberg figures -- LIGHTNING INJURY
31
Q
why are deep tissue burns relatively rare post-lightning strike?
A
short duration of electrical contact & flashover effect: tendency of lightning to travel over skin surface and discharge on ground --> lichtenberg figures
32
Q
how does lightining cause skeletal fracturs?
A
rapid heating of surrounding air, generating shock waves, can travel through body & cause mechanical trauma.
33
Q
rules re: cardiac pressure
A
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
Q
normal pulmonary pressure at rest? pulmonary HTN at?
A
at rest: 10-14mmHg.
pumonary HTN > or equal to 25mmHg.
35
Q
protein A. protein cell wall component (a single polypeptide chain)
A
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
Q
sounds from opening snap in mitral stenosis
A
abrupt halting of leaflet motion during mitral valve opening (due to fusion of mitral valve leaflets).
37
Q
most common cause of mitral stenosis
A
prior rheumatic carditis
38
Q
secretin S cells located...
A
duodenum. increase bicarb secretion from exocrine pancreas. stimulated by HCl in duodenum.
39
Q
role of thyroglobulin peroxidase (3)
A
(1) oxidation of inorganic iodine
(2) formation of mono- and diiodotyrosine
(3) coupling that forms T3 and T4.
40
Q
thyroglobulin
A
high molecular weight, glycosylated protein that is present within the thyroid follicle. TSH increases its gene transcription.
41
Q
role of thyroglobulin
A
iodine is added to tyrosine residues on thyroglobulin & stored there until thyoid follicular cells engulf, cleave for use.
42
Q
how does N. meningitidis get into the meningies
A
pharynx --> bloodstream --> choroid plexus ---> meninges

remember hematogenous bc of systemic signs (i.e. sepsis & characterestic petechial signs, waterhouse-friderichsen, etc)
43
Q
how does haemophilus influenza get into the meninges?
A
pharynx --> lymphatics --> meninges
44
Q
how can S. pneumonia get to meninges post0otitis media?
A
middle ear --> contiguous tissues --> meninges
45
Q
how does s. pneumonia and TB from lungs get into meninges?
A
primary lung focus --> blood --> meninges
46
Q
describe TB meningitis
A
chronic, characterized by monoctes & lymphocytes in CSF, primarily affecting BASAL meninges.
47
Q
typical adenovirus presentation
A
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
Q
calicivirus
A
Norwalk virus -- epidemic outbreaks of viral gastroenteritis
49
Q
bronchiolitis in infants caused by
A
RSV (paramyxovirus)
50
Q
arenavirus
A
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
Q
transport of unconjugated bilirubin into hepatocytes?

transported of conjugated bilirubin out of hepatocytes?
A
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
Q
describe conjugated bilirubin.
unconjugated bilirubin.
A
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
Q
which type of bilirubin can lead to jaundice?
A
BOTH unconjugated & conjugated (bilirubin glucuronides) can accumulate systemically and deposit in tissues --> jaundice.
54
Q
what 5 things can cause jaundice. which type of bilirubin is at play?
A
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
Q
gilbert syndrome
A
mild; low activity in UDP glucoronyl transferase (like in babies).

mild increase in unconjugated bilirubin

see jaundice with stress & fasting. otherwise, clinically silent.
56
Q
crigler-najar
A
ABSENT UDP-glucoronyl transferase. increased unconjugated bilirubin. die within a few years

rx: plasmaphoresis and phototherapy
57
Q
dubin-johnson
A
defective secretion of conjugated bilirubin. black liver. conjugated hyperbillirubinemia.

benign, autosomal recessive.
58
Q
rotor syndrome
A
mild defect in excretion of conjugated bilirubin. no black liver. conjugated hyperbillirubinemia.
59
Q
haptoglobin
A
produced by liver. released via exocytosis. decreases in hemolysis bc bound by free hemoglobin & removed by RES (liver and spleen).
60
Q
conjugated bilirubin in gut
A
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
Q
indirect billirubin =
A
unconjugated
62
Q
direct billirubin =
A
conjugated
63
Q
heme metabolism in RES (reticuloendothelial system)
A
heme ---> biliveridin (via heme oxygenase).

biliveridin ---> bilirubin
64
Q
sNRPs
A
small nuclear ribonucleoproteins. bind pre-mRNA to form splicesosome.
65
Q
southwestern blot
A
DNA-binding protein. probe w/ double stranded protein.

detects transcription factors, nucleases, etc
66
Q
c-Jun & c-Fos
A
nuclear transcription factors that bind to DNA via leucine zipper motif.

proto-oncogenes
67
Q
Ras
A
proto-oncogene that codes for membrane-bound G protein. activates leads to MAP kinase pathway.
68
Q
S-100 protein
A
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
Q
raloxifene
A
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
Q
oral medroxyprogesterone acetate
A
synthetic progesterone. reduces incidence of endometrial hyperplasia.

long-acting contraception.

associated w/ decreased bone density
71
Q
alendronate
A
bisphosphonate analogue of pyrophosphate. binds hydroxyapatite. stops osteoclasts.
72
Q
tamoxifen
A
SERM

AGONIST: uterus & bone

ANTAGONIST: breast

good for rx: breast cancer incidence and osteoporosis.

BUT, associated w/ endometrial cancer.
73
Q
clomiphene
A
SERM.

antagonist to ER in hypothalamus, blocks negative feedback to increase GnRH secretion (rx: infertility)
74
Q
who determines pairing of tRNA and amino acid
A
each AA tRNA combo has own AA-tRNA synthetase to link them. some can proofread their tRNA.

error rate = VERY LOW.
75
Q
sequence of amino acids in growing polypeptide chain determined by..
A
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
Q
causes of sensorineural hearing loss
A
meniere's disease, acoustic neuroma, presbycusis, ototoxic drugs

involving inner ear, cochlea, or auditory nerve.
77
Q
causes of conductive hearing loss
A
cerumen impaction, cholesteatoma, otosclerosis, external/middle ear tumor, tympanic membrane rupture, severe otitis media

obstruction of external sound vibrations to inner ear
78
Q
what metabolism processes occur in mitochondria?
A
pyruvate carboxylation, TCA, beta-oxidation, ketogenesis.

part of heme metabolism, urea cycle, gluconeogenesis.
79
Q
transketolase
A
enzyme in pentose phosphate pathway (HMP shunt).

uses B1 as cofactor
80
Q
test for B1 (thiamine deficiency)
A
w/ transketolase
81
Q
ornithine transcarbamoylase
A
converts ornithine + carbamoyl phosphate --> citrulline
82
Q
succinate dehydrogenase
A
succinate --> fumarate. inner mitochondrial membrane protein & fxn in electron transport chain too.
83
Q
3-hydroxy-3-methygutaryl-CoA lysase
A
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
Q
name a thiazolidinedione. mechanism?
A
-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
Q
adiponectin
A
levels low in type2 DM, leading to insulin resistance.

rx with thiazolidinediones increases adiponectin expression.
86
Q
1st generation sulfonylureas? 2nd generation?
A
1st: tolbutamide, chlorpropamide

2nd: glyburide, glimepiride, glipizide
87
Q
pramlintide
A
amylin analogs, decrease gastric emptying, decrease glucagon
88
Q
exenatide & liraglutide
A
GLP-1 analogs; increase insulin and decrease glucagon
89
Q
DPP-4 inhibitors: linagliptin, saxagliptin, sitagliptin
A
increase insulin, decrease glucagon release
90
Q
glutamate is a precursor for.. (2)
A
GABA and glutathione
91
Q
pheylalanine is a precursor for
A
tyrosine
92
Q
tyrosine is a precursor for
A
thyroxine (T4), DOPA (-->melanin), dopamine, NE, E
93
Q
cofactors in DOPA to NE synthesis
A
DOPA -> dopamine (B6).
dopamine -> NE (vit C).
NE -> E (SAM)
94
Q
B6 is generally required for what reactions
A
(1) transamination
(2) decarboxylation
(3) glycogen phosphorylase
95
Q
histidine is a precursor for
A
histamine
96
Q
glycine is a precursor for..
A
porphyrin --> heme
97
Q
tryptophan is a precursor for (2)
A
1. Niacin
2. 5-HT & melatonin
98
Q
arginine is a precursor for.. (3)
A
creatinine, urea, and nitric oxide
99
Q
rx for serotonin syndrome
A
cyproheptadine. first generation histamine antagonist w/ nonspecific 5-HT1 and 5-HT2 receptor antagonist properties.
100
Q
flumazenil
A
antidote for benzo overdose
101
Q
naloxone
A
antidote for narcotic overdose
102
Q
mycobacteria cell wall
A
incorporate mycolic acid into the outer portion of peptidoglycan.
103
Q
what anti-microbial agent is chemically similar to pyridoxine B6
A
isoniazid
104
Q
first line against legionella
A
erythromycin
105
Q
etiology of Hirschsprung's disease
A
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
Q
nitrate agent with highest bioavailabilty (~100%) if given orally?
A
isosorbide mononitrate (active metabolite of isosorbide dinitrate)
107
Q
nitroprusside? rx?
A
only IV. used in hypertensive emergency. notable cyanide toxicity.
108
Q
nitroglycerin
A
SUBLINGUAL. straight into systemic circulation (no first pass metabolism in liver)
109
Q
examples of lower motor neuron diseases (2)
A
poliomyelitis and werdnig-hoffman (autosomal recessive)
110
Q
rx for paroxysmal supraventricular tachycardia?
A
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
Q
multiple rounded & polygonal cells w/ abundant clear cytoplasm
A
clear cell carcinoma (most common subtype of renal cell carcinoma)
112
Q
presentation of renal cell carcinoma
A
triad of (1) hematuria (2) flank pain (3) palpable abdominal mass.

often have paraneoplastic (EPO, ACTH, PTHrP)
113
Q
hematuria, flank pain, palpable abdominal mass & elevated hemtocrit
A
EPO producing RCC
114
Q
metastatic brain cancer
A
metastasize within CNS, but rarely metastasize outside of CNS
115
Q
smoking and cervical cancer?
A
smoking is an independent risk factor!

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

not: diet, alcohol, family history
116
Q
nicotinic receptor
A
2 binding sites for ACh. Na+ and Ca++ influx, K+ efflux
117
Q
what happens to nonfunctional monoiodotyrosine and diiodotyrosine in thyroid
A
deiodination and iodine recycling
118
Q
ADH signalling cascade
A
activates V2 receptors (GPCR). transposition of aquaporin 2 to luminal cell membrane.
119
Q
water deprivation & vasopressin challenge.
A
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
Q
homer-wright rosettes
A
medulloblastoma
121
Q
primative neuroectoderm tumor
A
medulloblastoma. 2nd most common posterior fossa tumor. DROP METS
122
Q
3 prominent features of glioblastoma multiforme
A
1. white matter, cross midline
2. florid vascular prolif
3. pseudopalisading necrosis
123
Q
ependymoma
A
roof of 4th ventrical. pseudorossettes with GFAP+ processes tapering towards blood vessels.
124
Q
most common extracranial solid tumor in children
A
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
Q
c-myc normal function
A
nuclear phosphoprotein that functions as TRANSCRIPTION ACTIVATOR controlling cell proliferation, differentiation, and apoptosis.

overexpressed in Burkitt's Lymphoma t(8,14)
126
Q
fanconi anemia
A
mutation in DNA repair leading to anemia?
127
Q
5 year survival for small cell carcinoma (even w/ treatment)
A
< 1 year. usu have distant mets by diagnosis.
128
Q
pure red cell aplasia
A
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
Q
all patients with pure red cell aplasia should undergo..
A
chest CT, to see if thymoma present. resection can cure disease.
130
Q
MAJOR virulence factor of s. pneumonia
A
CAPSULE. without it, would not cause disease. has 82 diff capsules
131
Q
quellung rxn
A
Ab against capsule causes capsular swelling in vitro
132
Q
pneumolysin secreted by.. what does it do
A
s. pneumoniae. suppresses oxidative burst by phagocytes.
133
Q
capsule generally are
A
anti-phagocytotic!