Uworld Flashcards
(224 cards)
1
Q
Pt with diphyllobothrim latum is at risk for what?
What kind of organism is D. latum?
How is it ingested?
A
B12 deficiency and megaloblastic anemia
fish tapeworm
larvae in raw fresh water fish
2
Q
- large crusting mass in mandible
- 46 yo homeless man
- no water source, no etoh, or drug use, occ. smokes
- lumpy mass, “wooden”
- yellow colored healing ulcer
Dx?
pathogen?
description of what we would culture?
A
Actinomycosis
actinomyces israelii
forms sinus tracts that heal and recur, fibrosis/wooden, can shed sulfur granules
3
Q
Stool microscopy in V. cholerae and enterotoxigenic E. coli are unique because…
A
they cause purely toxin mediated watery diarrhea and cells are not damaged - no RBCs or WBCs in stool
4
Q
- very narrow zone of beta hemolysis
- tumbling motility at room temp
- multiply in fridge/cold enrichment
pathogen?
main process to eliminate?
A
listeria monocytogenes - facultative intracellular gram + rod
cell-mediated immune response needed bc its intracellular - circulating immune factors can’t reach; bacteria protein fragments on surface -> cytotoxic T cells -> lysis and macrophage develop via IFNy
5
Q
indurated painless ulcer on penis, no erythema, no LAD
Dx?
pathogen?
tx and MOA?
A
primary syphilis
treponema pallidum
penicillinm- binds and inhibits transpeptidase, blocks cell wall formation of binding D-alanine-D-alanine
6
Q
best steps for prevention of central venous catheter infections are…
A
- proper hand hygiene
- full barrier precautions during insertion
- chlorhexidine skin
- avoid femoral insertion site
- remove cath when no longer needed
7
Q
What is the number 1 vector borne disease in the US?
It is most prevalent in what area?
pathogen?
how is this transmitted?
appropriate tx for adult and child?
A
lyme disease
NE states
borrelia burgdorferi
ixodes tick
adult - doxy; child or prego - amoxicillin
8
Q
pt with dysphagia and dialated esophagus - dx?
pt is from central or S. America so it could be secondary to…
How?
What else could this cause?
A
achalasia
chagas disease
destruction of submucosal (meissner) and myenteric (auerbach) plexi
nonischemic cardiomyopathy and megacolon
9
Q
intense pruritis in inguinal genital area
prior STDs and no other ssx
excoriations and image of thing clinging to pubic hair
pathogen? transmitted?
how would you dx it?
tx? MOA?
A
Phthirus pubis - human pubic louse
skin to skin
dx with image
tx with topical permethrin
MOA: blocks Na+ ion conduction, leading to paralysis and death
10
Q
What is Thayer Martin agar made of?
What else can Neisseria grow on?
A
- vancomycin, colistin, nystatin
- chocolate agar
11
Q
How is chocolate agar made and what will grow on it?
A
RBCs heated to 56C to lyse them, releasing factor V and factor X
haemophilus influenza and neisseria
12
Q
exposure to farm poop, myalgias, fatigue, fever >10d, retro-orbital HA
nl WBC, thrombocytopenic, increased LFTs
Dx?
pathogen?
What is another common ssx?
A
Q fever
Coxiella burnetti
pna with lobar consolidation
13
Q
Why and how long should one use mefloquine chemoprophylaxis for malaria?
A
if going to endemic region continue for 4 weeks s/p return
ensures elimination of hepatic shizonts because mefloquine only works on replicating parasites
14
Q
Where is the facial nucleus found?
A
caudal pons near fourth ventricle
15
Q
An epidural hematoma is MCC by rupture of what artery?
What is this artery a branch of and where does it course?
A
middle meningeal artery
terminal branch of maxillary a. (off ECA)
goes through forament spinosum to enter cranium
16
Q
What two factors does haemophilus need to grow?
What pathogen facilitates growth via the ‘satellite phenomenon’?
A
X factor - hematin
V factor - NAD+
S. aureus
17
Q
+ HBsAg
+ HBeAg
+/- Anti-HBcAg (depending on how far along infection is)
dx?
A
acute infection Hep B
18
Q
- 35 yo HIV+
- 80% compliant with tx
- CD4 ct 190
- viral load 100k
pt is at risk for what disease?
tx prophylactically?
MOA of rx?
A
CD4 <200 risk pneumocystis pna and toxoplasma gondii
tx prophylactically with TMP-SMX
MOA- works on folate pathway
19
Q
4 yo M with skin lesions on face x2 days, golden yellow crust
dx? pathogen? sequelae?
A
impetigo
S. aureus or S. pyogenes
post-strep glomerular nephritis (facial edema, dark urine/hematuria, HTN, RBC casts in urine)
acute rheumatic fever (usually s/p GAS pharyngeal infection, rather than skin infection)
20
Q
several months of pain and itching perirectally on HIV+ pt with occasional rectal bleeding
single hard mass and ulceration in anal canal, no LAD, CD4 ct 280
dx? pathogen to initiate disease process?
A
anal squamous cell carcinoma (often ulcerative)
from HPV 16 and 18
21
Q
What would be the markers for a chronic state of Hep B infection?
A
- HBsAg
- Anti-HBcAg
- +/- HBeAg or Anti-HBeAg
22
Q
What are 2 parasites that cause disease in RBCs?
What are their vectors?
A
- plasmodium - anopheles misquito
- babesia - ixodes scapularis tick
23
Q
2 yo with vesicles on palate and lips
dx?
pathogen? describe
A
gingivostomatitis
HSV-1
dsDNA enveloped
24
Q
fever, cough, rhinorrhea, conjunctivits
maculopapular rash on face and descends, spots in mouth too
dx?
pathognomonic for it?
transmission?
vaccine?
describe pathogen
A
measles/rubeola
koplick spots
airborne/ person to person
MMR - live attenuated
paramyxoviridae - enveloped, negative sense RNA, non segmented virus
25
describe pseudomonas aeruginosa
gram negative rod, non lactose fermenting on Macconkey, oxidase +, motile
26
lesions in lower lobes with perihilar lymph node involvement form what?
seen in what disease?
ghon complex
primary TB
27
hepatic abscess in first world country - source?
routes of possible infection?
bacteria - S. aureus via hematogenous spread
biliary tract inf.
portal vein pyemia
hepatic a.
direct from adjacent
penetrating trauma
(enteric bacteria usually)
28
fungal hyphae branching at acute angles with septation
pathogen?
aspergillus fumigatus
29
tx of diphtheria?
diphtheria antitoxin - that has preformed, neutralizing abs that bind and inactivate circulating toxin
does not work on toxin already in cells
C. diphtheriae doesn't generally enter blood
30
developing nation, cyst in liver, no prior ssx until now
dz/pathogen?
tx? rx?
echinococcus granulosis parasite
surgical resection of cyst
rx: albendazole
31
East Africa, small insect bite (4-5cm) indurated erythematous and rubbery swelling
myalgias, arthralgias, and intermittent fevers
blood smear: long slender, flagellated protozoa with kinetoplasts
Dx? pathogen? vector spread? ssx?
African trypanosomiasis/African sleeping sickness
Trypanosoma brucei (Tbr and Tbg)
tsetse fly
posterior cervical LAD aka Winterbottom's sign
32
P.ovale and P. vivax have dormant hepatic phase called...
What is unique about this?
What would be the tx to prevent this?
hypnozoite
can reactivate several months after return from an endemic region
tx with primaquine to prevent reactivation
33
Why does staphylcoccal scaled skin syndrome occur?
What is Nikolsky's sign?
production of exotoxin exfoliation by staph
widespread epidermal sloughing especially with gentle pressure
34
* sore throat x2days
* now fever, chills, and diffuse erythematous blanching rash on chest and abdomen with 1-2mm papules
* 12 yo
* throat and tongue erythematous
dx?
pathogen?
sequelae most dangerous?
scarlet fever
S. pyogenes (GAS) - pyrogenic exotoxins
rheumatic fever
35
What is the exchange of genes between 2 chromosomes via crossing over within homologous regions called?
What kind of genome can do this?
recombination
2 dsDNA genomes needed
36
What is the only glycosylated HIV polyprotein?
product of what gene?
it is then cleaved into...
gp 160
env gene
gp120 and gp41
37
What does a pt with impaired cellular mediated immunity and prego lady in third trimester have in common?
Listeria
38
UMNs for contralateral side of the body and face are located where?
precentral gyrus (face most lateral, then UE, then most medial is LE)
39
In HELLP syndrome, how do you prevent sz?
What are signs of toxicity of this drug?
magnesium sulfate drip
loss of DTRs, respiratory paralysis, coma
40
What is Group D strep?
How does it enter the blood stream?
tx?
S. gallolyticus, previously S. bovis
in GI tract normally, so any interruption in mucosa, esp. colon CA
penicillin G for 4 weeks
41
Chronic Q fever is an infection \>6 mo and more likely in what pts?
pregnant, I/C, or having an underlying valvular pathology
42
How does HBV facilitate infection of HDV?
HBV creates protein that coats HDV viral particles
43
pt has cat, probable AIDS, sz, AMS
CT shows ring lesions enhanced with contrast
pathogen?
toxoplasma gondii
44
What are inflammatory anaphylatoxins that trigger histamine release from mast cells, resulting in vasodilation and enhanced vascular permeability?
C3a, C4a, and C5a
45
Besides being anaphylatoxins, what do C3a and C5a do, respectively?
* C3a
* recruits and activates eosinophils and basophils
* C5a
* recruits and activates neutrophils, monocytes, eosinophils, and basophils
46
What are some significant chemotactic agents?
IL-8
n-formylated peptides
leukotriene B4
5-HETE (the leukotriene precursor)
complement component C5a
47
What pure sensory nerve innervates the posterolateral leg and lateral foot?
sural nerve
48
failure of pt's neutrophils to turn blue on nitroblue tetrazolium testing is characteristic of what?
this is most often caused by an X linked mutation affecting...
chronic granulomatous disease
NADPH oxidase
49
Neutrophils affected by Chronic granulomatous disease are unable to kill...
this results in...
catalase-producing organisms
resulting in recurrent bacterial and fungal infections that frequently involve the lungs, skin, and lymph nodes
50
coagulase from staph aureus activates prothrombin, resulting in conversion of firbinogen to fibrin
how is this a virulence factor?
leads to fibrin coating of the organism and resistance to phagocytosis
51
What is the major virulence factor produced by Clostridium perfringens?
How does this work?
lecithinase (alpha toxin)
has phospholipase C activity, increases platelet aggregation and adherence molecule expression on leukocytes and endothelial cells resulting in vasoocclusion and ischemic necrosis of infected tissues
52
What are three stop codons?
When ribosome encounters a stop codon, what happens?
UAA, UAG, UGA
releasing factor proteins bind to the ribosome and stimulate release of the formed polypeptide chain and dissolution of the ribosome-mRNA complex
53
What facilitates tRNA binding and the translocation steps of protein synthesis?
elongation factors
54
What is the major cause of morbidity and mortality in pts recovering from SAH?
How will it present?
How can this be prevented?
vasospasm
4-12 days s/p initial insult - causes cerebral ischemia, presenting as new-onset confusion and/or focal neurologic deficits
nimodipine - selective Ca2+ channel blocker
55
Most intracranial schwannomas are found where and attach to what nerve?
What are they called here?
cerebellopontine angle
attached to CN VIII
acoustic neuromas
56
What are common ssx of acoustic neuromas?
bilateral acoustic neuromas occur in what disease?
tinnitus, vertigo, hearing loss
Neurofibromatosis (NF) type 2
57
How does NF type 2 differ from NF-1?
What is the gene mutation a/w each and clinical presentation?
NF2 causes fewer cutaneous manifestations and presents with CNS involvement
* NF-1
* NF-1 tumor suppressor gene; codes protein neurofibromin
* chromosome 17
* cafe-au-lait spots, multiple neurofibromas, lisch nodules
* NF-2
* NF-2 tumor suppressor gene; codes protein merlin
* chromosome 22
* bilateral acoustic neuromas
58
Mutation of APC gene (adenomatous polyposis coli) is on what chromosome and what is it a/w?
chromosome 5
familial adenomatous polyposis syndromes and colon cancer
59
What is the MC mutation found in human cancers? What chromosome is it on?
What is it also associated with?
p53 tumor suppressor gene on chromosome 17
Li-Fraumeni syndrome, rare familial syndrome characterized by development of breast cancer, sarcomas, brain tumors, leukemia, and adrenocortical tumors at a young age
60
Where is RB1 tumor suppressor gene found?
Mutations here put someone at risk for what?
chromosome 13
increase risk of retinoblastoma and osteosarcoma
61
What is the mutation in Hippel-Lindau disease?
It is characterized by...
mutation of VHL gene on chromosome 3
renal cysts, renal cell carcinomas, and hemangioblastomas of the cerebellum and retina
62
What is the pathophysiologic mechanism behind altitude sickness?
hypobaric hypoxia
decreased pO2 in the air and blood, causes tissue hypoxia resulting in stimulation of peripheral chemoreceptors causing hyperventilation
this decreases pCO2 in blood, raising the pH (respiratory alkalosis)
renal bicarb excretion compensates for the alkalosis, stabilizing the pH toward the normal range within about 48 hours
63
What nerve provides sensation to the suprapubic adn gluteal regions and motor function to the anterolateral abdominal wall muscles?
iliohypogastric nerve
64
What nerves accompanies the spermatic cord through the superficial inguinal ring and provides sensation to the upper and medial thigh and parts of the external genitalia?
ilioinguinal nerve
65
What nerve provides sensation to the upper anterior thigh and motor function to parts of the genitalia (cremasteric reflex or mons pubis)?
genitofemoral nerve
66
What is the first line tx for status epilepticus?
MOA?
IV benzos
enhance GABA-A receptor, increasing influx of Cl- ions, leading to hyperpolarization of the postsynaptic neuron and suppression of AP firing
67
What is the pathophysiological reason for peripheral neuropathy in diabetic pts?
endoneural arteriole hyalinization and accumulation of sorbitol leading to osmotic nerve injury
68
What are the virulence factors of B. pertussis that allow it to strongly attach to respiratory epithelium?
pili, filamentous hemagluttinin, pertactin
69
What inflammatory exotoxins does B. pertussis have and what do they do?
* tracheal cytotoxin - directly damages and destroys ciliated epithelial cells, leading to a loss of airway protection, subsequent microaspiration, and development of paroxysmal cough
* pertussis toxin - an AB toxin that enters cells and activates adenylate cyclase leading to alterations in cellular signaling that inhibit phagocyte activity and can cause lymphocytosis
70
What is first line tx of CMV colitis and retinitis?
MOA?
AE?
ganciclovir
inhibits viral synthesis by blocking CMV DNA polymerase
also blocks host DNA polymerase to a lesser degree, causing neutropenia, anemia, and thrombocytopenia
71
In treating HIV, what drugs are a/w myopathy and rhabdomyolysis?
integrase inhibitors like raltegravir and dolutegravir
72
What is the most abundant amino acid in collagen?
How does its triple helical formation occur?
glycine
occurs d/t the repetitive amino acid sequence within each alpha chain, in which glycine occupies every third aa position
73
How does fomepizole work do combat alcohol poisoning?
decreases the conversion rate of the parent alcohols into their toxic metabolites
(competitive inhibitor of alcohol dehydrogenase)
74
What acid-base abnormalities are characteristic of acute salicylate intoxication?
respiratory alkalosis
anion gap metabolic acidosis
75
What triad is seen in adults with aspirin intoxication?
fever, tinnitus, and tachypnea
76
What is the primary type of collagen in mature scars?
collagen type I
77
bradycardia and dropped P waves are consistent with what?
This is commonly resulting from...
sick sinus syndrome
age related degeneration of the SA node
78
narrow QRS complex preceded by long pause and no P wave
junctional escape beat
79
asymptomatic pt with a harsh, holosystolic murmur best heard at mid to lower left sternal border
What will happen to the murmur with handgrip?
small Ventral septal defect
worsens murmur
80
systolic crescendo-decrescendo murmur best heard at the base of the heart with radiation to the neck
aortic stenosis
81
a wide, fixed-split S2 and a systolic ejection murmur that is best heard at the upper left sternal border due to increased flow across the pulmonic valve
atrial septal defect
82
What statistical analysis test should you use to compare the means of 2 groups of subjects?
two-sample t test
83
What statistical test is best when using categorical data?
"goodness of fit"
chi square test
84
B1
primary function
syndromes of deficiency
thiamine
decarboxylation of alpha-keto acids (carb metabolism)
beriberi (peripheral neuropathy and HF) and Wernicke-Korsakoff syndrome
85
B2
primary function
syndromes of deficiencies
riboflavin
mitochondrial electron carrier (FMN, FAD)
angular cheilosis, stomatitis, and glossitis; normocytic anemia
86
B3
primary function
syndrome of deficiency
niacin
Electron transfer reactions (NAD/NADP)
Pellagra (dermatitis, dementia, diarrhea); peripheral neuropathy
87
B6
primary function
deficiency
pyridoxine
transamination of amino acids (amino acid synthesis)
cheilosis, stomatitis, glossitis
88
B9
primary function
deficiency
folate, folic acid
hydroxymethyl/formyl carrier (purine and thymine synthesis)
megaloblastic anemia; neural tube defects (fetus)
89
B12
primary function
deficiency
cobalamin
isomerase and methyltransferase cofactor (DNA and methionine synthesis)
megaloblastic anemia; neurologic deficits
90
Vitamin C
primary function
deficiency syndromes
ascorbic acid
hydroxylation fo proline and lysine (collagen synthesis)
scurvy
91
absent P waves, irregularly irregular RR intervals, narrow QRS complexes
atrial fibrillation
92
polymorphic ventricular tachycardia that occurs in the setting of a congenital or acquired prolonged QT interval
torsades de pointes
93
What are some medications that prolong the QT interval, predisposing a pt to torsades?
antiarrhythmatics - sotalol, quinidine
antipsychotics - haloperidol
abx - macrolides and fluoroquinolones
94
autosomal dominant mutations in the TTN gene, which encodes for the sarcomere protein titin are the MCC of...
familial dilated cardiomyopathy
95
What could occur 5-14 days s/p MI and presents with sudden onset of chest pain, profound shock, and rapid progression until death?
Morphologically, what does this look like?
Left ventricular free wall rupture
ruptures appear as a slit like tear in the infarcted myocardium with a preference for the L ventricle due to higher systolic pressures
96
How does digoxin work?
slows the ventricular rate during A fib by increasing the parasympathetic tone, leading to inhibition of AV node conduction
also used in HF by inhibiting the Na-K-ATPase pump, having an inotropic effect
97
What histopathology is most consistent with acute graft rejection?
when would this acute rejection be most likely to occur?
how is this process mediated?
dense infiltrate of mononuclear cells usually composed of mostly T lymphocytes
1-4 weeks s/p transplant
cell mediated - host T cells sensitization against graft (foreign) MHC antigens
98
acute cessation of blod flow through an organ immediately after anastomosis of recipient vessels to donor vessels is characteristic of...
why does this occur?
hyperacute graft rejection
occurs due to preformed abs in the recipient directed against donor antigens
99
concentric coronary atherosclerosis found on angiography s/p heart transplant means...
donor heart had preexisting atherosclerosis prior to the organ being harvested
100
perivascular infiltrate with abundant eosinophils is a histopathologic presentation consistent with...
this is often due to...
hypersensitivity myocarditis
initiation of a new drug therapy, against which the body mounts and atopic response
101
scant inflammatory cells and interstitial fibrosis is most characteristic of what s/p transplant?
how is this process mediated?
when does it occur?
chronic rejection
mediated by host T cell and B cells as well as abs and classically occurs months to years following solid organ transplant
102
young pt presents with dyspnea, LE edema, JVD, and pulomnary crackles - consistent with what?
if pt has had a symptomatic viral prodrome, what should I be suspecting as the dx?
decompensated heart failure
dilated cardiomyopathy due to viral myocarditis
103
top 3 viruses implicated in causing DCM?
coxsackie, adneovirus, influenza virus
104
direct damage to cardiomyocytes, leading to myocardial contraction dysfunction (systolic dysfunction), volume overload, and ventricular dilation
dilated cardiomyopathy
105
systolic anterior motion of the mitral valve; exercise induced syncope; sudden cardiac death in young athletes
hypertrophic cardiomyopathy
106
what heart disease occurs due to long standing uncontrolled HTN?
concentric LV hypertrophy
107
a crescendo-decrescendo murmur with LV hypertrophy probably has what valve issue?
aortic stenosis
108
pt with rheumatic heart disease might develop what that would cause palpitations and exertional dyspnea?
mitral stenosis/regurg leading to L atrial enlargement and extrinsic compression of the esophagus
109
What can L atrial enlargement end up compressing?
esophagus and sometimes the L recurrent laryngeal nerve (hoarse voice and chronic cough)
110
Where is the AV node located?
Why would you ablate this area?
in endocardium of RA, near septal leaflet of the tricuspid valve and the orifice of the coronary sinus
tx pharmocologic resistant arrhythmias, possibly Afib
111
What area would you perform an ablation on in order to treat A flutter?
isthmus between the IVC and tricuspid annulus
112
What is the MC cardiac malformation in pts with Turner Syndrome?
What will be the audible presentation of this?
bicuspid aortic valve
early systolic, high frequency click (in nonstenotic bicuspid) heard over the right second interspace
113
What are the MC cardiac anomalies in Down Syndrome?
What sounds are heard with these?
* complete atrioventricular canal
* ASD (fixed splitting of second heart sound)
* VSD (holosystolic murmur at the left lower sternal border)
114
mid-systolic click, often with late systolic murmur, is hallmark of ....?
It is more common in what kind of disorders?
Mitral valve prolapse
MC in CT disorders like Marfan's and Ehler's Danlos
115
elevated levels of homocysteine are an independent risk factor for...
thrombotic events (venous thromboses, coronary artery disease, and ischemic stroke
116
How is homocysteine metabolized?
* to methionine via remethylation
* occurs with the donation of methyl from methyl-THF via methionine synthase
* has Vit B12 (cobalamin) as cofactor
* to cystathione via transsulfuration
* via cystathionine-beta-synthase
* subsequently to cysteine via cystathionase, with B6 as cofactor
117
Once a methyl group is donated from methyl-THF to homocysteine, how is it regenerated?
enzyme MTHFR (methylene tetrahydrofolate reductase) using FAD as cofactor
118
What is the MC genetic cause of hyperhomocysteinemia?
MTHFR deficiency
119
What is elevated in both folate and Vit B12 deficiencies?
What is only elevated in Vit B12 deficiency?
homocysteine is elevated in both
methylmalonyl-CoA is only elevated in the one
120
What do the 6 embryological pharyngeal/aortic arches give rise to and what are the cranial nerves associated with each?
1. maxillary artery (portion) and trigeminal nerve
2. stapedial artery (regresses) and facial nerve
3. common carotid artery, proximal internal artery and glossopharyngeal nerve
4. true aortic arch, subclavian arteries and superior laryngeal branch of Vagus nerve
5. obliterated
6. pulmonary arteries, ductus arteriosus and recurrent laryngeal branch of Vagus
121
finding in cardiac tamponade referring to an exaggerated drop in systolic blood pressure (\>10mmHg) during inspiration
what else can this be found in?
pulsus paradoxus
severe asthma, COPD, hypovolemic shock, and constrictive pericarditis
122
How do patients with chronic aortic regurgitation (possibly as sequelae of infective endocarditis) remain asymptomatic for long periods of time?
* aortic regurg causes volume overload in LV, distending it, triggering eccentric hypertrophy
* this causes an increase in stroke volume in order to maintain cardiac output
123
A CVA in the setting of known venous thromboembolic disease is suspiscious for...
what is this?
what sound might be associated?
paradoxical embolism
* thrombus from the venous system crosses into the arterial circulation via an abnormal conenction between the R and L cardiac chambers
* probably happens during periods of transient shunt reversal (straining or coughing)
Atrial L to R shunts cause wide and fixed splitting of S2
124
CCBs work by ...
block calcium channels to slow spontaneous depolarization
125
this drug reduces platelet activation by inhibiting platelet phosphodiesterase (which breaks down cAMP) and is also a direct arterial vasodilator
what will administration of this drug ultimately cause?
cilostazol
decrease in claudication symptomes and an increase in pain-free walking distances in patients with peripheral arterial disease
126
monoclonal ab that inhibits platelet aggregation by targeting the platelet IIb/IIIa receptor
abciximab
127
anticoagulant that potentiates antithrombin III, resulting in the inactivation of thrombin and other factors
heparin
128
direct thrombin inhibitor primarily used in teh treatment of heparin-induced thrombocytopenia
argatroban
129
oral anticoagulant that is a competitive inhibitor of vit K epoxide reductase and reduces production of vit K dependent coagulation factors (II, VII, IX, X, protein C and protein S)
warfarin
130
second line tx for A fib with RVR and more useful in pt with underlying systolic cardiac dysfunction
what are this drug's major effects?
* digoxin
* increased vagal tone
* slowing of conduction through the AV node (rate control)
* Na-K-ATPase inhibition
* increased intracellular Na and Ca (increases cardiac contractility)
131
Overuse of what vitamin can cause intracranial hypertension, skin changes, and hepatosplenomegaly?
vitamin A
132
What vitamin deficiency is characterized by cheilosis, stomatitis, glossitis, dermatitis, corneal vascularization, and ariboflavinosis?
Vit B2 (riboflavin)
133
what is associated with higher mortality rates due to hemorrahagic stroke in adults and higher rates of necrotizing enterocolitis in infants?
large doses of Vit E
134
What is the MC pineal gland tumor and how do they present?
If this tumor is located elsewhere in the brain, where would it be and what would it cause?
Germinomas
present with obstructive hydrocephalus and dorsal midbrain (Parinaud syndrome)
can also be in the suprasellar region and cause endocrinopathies due to pituitary/hypothalamic dysfunction
135
What causing and what does Parinaud syndrome consist of?
* direct compression of the pretectal region of the midbrain
* limitation of upward gaze with downward gaze preference,
* bilateral eyelid retraction (Collier sign, sclera visible above the superior corneal limbus),
* and light-near dissociation (Argyl-robertson)
136
What kind of cells do germinomas arise from?\>
embryonic germ cells
137
MC cerebellar tumor in children?
presentation?
medulloblastoma
gait and limb ataxia, intention tremor, nystagmus
138
What is the pathway of the median nerve in the forearm?
medial aspect of antecubital fossa betweent he humeral and ulnar heads of the pronator teres \> goes distal b/t FDS and
FDP \> into hand within flexor retinaculum
139
How would you diagnose cryptococcus neoformamns meningoencephalitis?
LP - detect polysaccharide capsule in CSF using latex agglutination test
india ink staining can also reval round or oval budding yeast
140
What is the anterior pituitary derived from?
Rathke pouch, evagination of surface ectoderm that lines the fetal oral cavity
141
What are derivatives of surface ectoderm?
* anterior pituitary (Rathke pouch)
* lens and cornea
* inner ear sensory organs, olfactory epithelium
* nasal and oral epithelial linings, salivary glands
* epidermis, sweat and mammary glands
142
What are derivitives of the neural tube?
* brain and spinal cord
* posterior pituitary, pineal gland
* retina
143
What are derivitives of neural crest cells?
* neural ganglia, adrenal medulla
* Schwann cells; pia and arachnoid mater
* aorticopulmonary septum and endocardial cushions
* branchial arches (bone and cartilage)
* skull bones
* melanocytes
144
MOA of anticonvulsant drug lamotrigine?
AEs?
What other anticonvulsants are associated with this severe AE?
blocks voltage gated Na channels
10% get rash, 1% get SJS-TEN (esp children)
carbamazepine, phenobarbital, and phenytoin
145
presence of endometrial glandular tissue within the myometrium
dx?
ssx?
who?
adenomyosis
menorrhagia and dysmenorrhea, uniformly enlarged uterus with normal appearing endometrial tissue on biopsy
common in middle aged parous females
146
What causes Henoch-Schonlein Purpura?
circulating IgA-antigen immune complexes (type III HS reaction)
deposition in walls of small vessesla dn renal mesangium leads to recruitment of neutrophils and lymphocytes as well as activation of complement via the alternate/lectin pathways
147
What is the first and second MCC of hematogenous osteomyelitis?
1. Staph aureus
2. Strep pyogenes
148
What is the MC associated arrythmia with WPW syndrome?
what is this and how does it manifest?
atrioventricular reentrant tachycardia
a type of paroxysmal supraventricular tachycardia that occurs due to reentry of electrical impulses through the accessory conduction pathway
intermittent palpitations, sensation of racing heart, lightheadedness or syncope
149
what is released from eosinophils in the late stage of a type I HS reaction and causes localized tissue damage?
major basic protein
150
what is a secondary inflammatory mediator that must be synthesized from phospholipid prior to being released from activated mast cells and basophils?
what does it do once released?
platelet-activating factor
stimulates bronchospasm and increased vascular permeability
151
What is the major stimulator of respiration in healthy individuals?
A change in this will stimulate what?
What happens in COPD?
arterial partial pressure of CO2
slight increase stimulates central chemoreceptors and triggers increased ventilation
response to PaCO2 is blunted and hypoxemia can contribute to respiratory drive
152
presence of multiple, genetically different cell lines within the body
types?
mosaicism
* somatic mosaicism
* affects cells forming the body, causing disease manifestations to develop in affected individuals
* MC - 45,X/46,XX (mild form of Turner syndrome or asymptomatic)
* germline mosaicism
* affects cells giving rise to gametes, allowing the affected genes to pass to the offspring
* chance of a child being affected depends on the proportion of gametes that carry the mutation
* the affected parent does not have clinical manifestations
153
describe dizygotic v monozygotic twins in utero
* dizygotic twins
* can be different sexes
* from fertilization of 2 oocytes, by 2 different sperm
* always have 2 amnions and 2 chorions
* chorions and placentas may be fused depending on proximity of implantation
* monozygotic twins
* from fertilization of single oocyte and develop from 1 zygote
* same sex, genetically identical and are similar in appearance
* can occur at different stages of embryonic development
154
How do fibrate medications (fenofibrate and gemfibrozil) cause the formation of cholesterol gallstones?
inhibit cholesterol 7alpha-hydroxylase, which catalyzes the rate-limiting step in the synthesis of bile acids
reduced bile acid production results in decreased cholesterol solubility in bile and will favor the formation of cholesterol gallstones
155
What is the physiology behind myometrial smooth muscle cells communication prior to delivery?
What do gap junctions consist of?
* estrogen stimulates upregulation of gap junctions between individual myometrial smooth muscle cells
* increase in gap junction density at delivery heightens myometrial excitability
* estrogen also increases espression of uterotonic (eg, oxytocin) receptors, which mediate calcium transport through ligand-activated calcium channels
* gap junctions consist of aggregated connexin proteins (eg, connexin-43) that allow passage of ions between myometrial cells
156
what does the combination of an increase in gap junction density and uterotonic receptors (both upregulated by estrogen) result in?
coordinated, synchronous labor contractions
157
autoantibodies to hemidesmosomes
ddx?
what are hemidesmosomes?
* bullous pemphigoid, pemphigoid gestationis
link cells to basement membrane via integrins, the transmembrane anchor proteins
158
What are tight junctions comprised of? What enterotoxin can compromise the efficacy of tight junctions?
* claudins and occludin, serving as paracellular barriers to water and solutes
* enterotoxin from Clostridium perfringens binds claudin and interferes with tight junctions in the intestinal barrier
* water loss from the tissue to the intestinal lumen results in watery diarrhea
159
highly sensitive cytogenic test that can identify the presence of chromosomal duplications and large deletions and translocations
How does this test work?
Fluorescence in situ hybridization (FISH)
FISH probes are ssDNA segments that are a few hundred kilobases in length; they are added to the cell of interest and anneal to complementary regions of teh cell chromsome, which allows the area of interest to be identified visually
160
used to quantify antibodies or antigens in a fluid
ELISA - enzyme-linked immunosorbent assay
161
flow cytometry is often used in the diagnosis of...
how?
leukemia
laser-based test elevated surface markers (CD5) on individual cells, not chromosomal duplications
162
technique that size-fractionates proteins in a gel and then targets a specific mRNA sequence of interest; can determine the quantity and size of a particular mRNA section
Northern blotting
163
technique that size-fractionates proteins in a gel and then targets a specific protein using an antibody with a radiotracer/enzyme; often used to confirm positive ELISA test in the setting of HIV or Lyme disease
Western blotting
164
persistent pattern of violating major societal norms or the rights of others; behaviors include aggression toward people and animals, deceitfulness or theft, destruction of property, and serious violation of rules
how long must this go on?
conduct disorder
\>12 mo
165
\>18 yo pt, pattern of violation of basic societal rules and the rights of others and requires a history of some symptoms of conduct disorder before age 15
antisocial personality disorder
166
involves a pattern of angry/irritable mood and argumentative/defiant behavior toward authority figures;
NO physical aggression, stealing, or destruction of property
oppositional defiant disorder
167
What all does IL-2 do? Where do they come frome?
produced by helper T cells,
* stimulate growth of CD4 and CD8 T and B cells
* activates natural killer cells and monocytes
168
What increases expression of MHC class I and II, improving antigen presentation in all cells?
IFN-y
169
In a pt with hypothyroidism, why would they be having nipple discharge?
* hypothyroid (decrease T3 and T4)
* increase TRH
* TRH stimulates prolactin secretion
170
What is the most important virulence factor allowing E. coli to be a major cause of neonatal meningitis?
how?
could the baby get this again?
K1 capsular antigen
facilitate survival in the blood by preventing recognition of bacterial antigens, complement deposition, and subsequent phagocytosis
K1 capsule is immunogenic and anti-capsular antibodies are protective against repeat infections
171
After acquiring schistosomiasis via contact with freshwater sources that contain snails infected with Schistosoma larvae, how can you tell what species is infecting?
What are clinical manifestations?
what is pathognomonic for hepatic shistosomiasis?
* S. japonicum and S. mansoni
* intestinal and hepatic shistosomiasis
* S. haematobium
* urinary shistosomiasis
from TH2 mediated granulomatous response directed against the eggs that is composed of infiltrating TH2 cells, eosinophils, and M2 macrophages
leads to the development of marked fibrosis and ulceration and scarring of the bowel or bladder/ureters (depending on the species)
eggs that settle into the presinusoidal radicals of the portal vein can cause periportal "pipestem" fibrosis (pathognomonic for hepatic shistosomiasis)
172
What is the primary site of ribosomal RNA (rRNA) transcription?
What enzyme functions exclusively to transcribe the 45S pre-rRNA gene into a single template?
What is this single template subsequently processed into?
nucleolus
RNA-polymerase I
18S, 5.8S, and 28S rRNAs
173
What is the type of RNA produced from RNA polymerase II and what is their function?
* messanger RNA
* translated by ribosomes to form specific proteins
* small nuclear RNA
* involved in mRNA splicing and transcription regulation
* microRNA
* cause gene silencing via translation arrest or mRNA degradation
174
What type of RNA does RNA polymerase III produce and what is their function?
by transcribing DNA to form small RNA molecules like
* transfer RNA
* adaptor molecule linking codons with specific amino acids
* 5S ribosomal RNA
* essential component of 60S ribosomal subunit
(genes located outside the nucleus)
175
What screen is used in the second trimester to identify pregnancies at high risk for congenital defects?
How does this do so?
* maternal serum quadruple screen
* AFP
* estriol
* b-hCG
* inhibin A
looked at in the context of gestational age to calculate risk of congenital defects in fetuses
176
tobacco use during pregnancy increases the risk of fetal growth restriction (FGR) and placental insufficiency - what would be decreased in the maternal serum?
decreased estriol levels are associated with placental abnormalities and FGR
177
What happens to concentrations of substances as fluid runs along the proximal tubule?
* increase in concentration
* PAH
* creatinine
* inulin
* urea
* decrease in concentration
* bicarb
* glucose
* amino acids
178
What neural tract mediates coordinated horizontal eye movements?
medial longitudinal fasciculus
179
internuclear ophthalmoplegia is a disorder of conjugate horizontal gaze in which...
what is preserved?
what is usually damaged that causes this?
the affected eye (ipsilateral to the lesion) is unable to adduct and the contralateral eye abducts with nystagmus
convergence and pupillary light reflex are presevered
MLF
180
Compare the rashes of rubella and rubeola/measles?
* rubella spreads faster and does not darken or coalesce
* will have postauricular and occipital LAD
* both are maculopapular and will spread descendingly
181
What parasite does a black fly transmit?
dz?
What rx tx?
* onchocerca volvulus
* Onchocerciasis
* second leading infectious cause of blindness
* "river blindness"
* tx: ivermectin
182
Who is more susceptible to vibrio cholerae infection and why?
pt with achlorhydria (decreased gastric acid production)
V. cholerae is very acid sensitive so a high burden is usually required in a healthy pt for infection/ssx to present
183
What do gp120 and gp41 do?
Why must they be glycosylated?
* gp 120 - viral attachment
* gp41 - viral fusion with host
* immune evasion - acts as shield for conserved regions
* host cell binding
* proper protein folding
184
What rx tx sporothrix?
itraconazole
185
acute febrile illness with HA, retro-orbital pain, and joint and muscle pain; hemorrhage and thrombocytopenia, leukopenia, hemoconcentrated
dx?
transmission?
other dz with same vector?
dengue fever
Aedes aegypti misquito
Chikungunya (febrile, flu-like, polyarthralgias, diffuse macular rash)
186
What two major(ish) illnesses do S. mutans and S. sanguinis cause?
How do these Viridans Strep adhere to structures to cause these issues?
dental carries, endocarditis
* production of insoluble extracellular polysaccharides (dextrans) using sucrose as a substrate
* allows adherence to enamel
* and fibrin-platelet aggregates on damaged heart valves
187
pyrrolidonyl arylamidase + bacteria
PYR+ = S. pyogenes, Enterococcus
188
homogenous, thin, white discharge in vagina, no erythema
dx?
what happens to pH?
micro?
tx?
test for via..
* bacterial vaginosis
* pH is going up \>4.5
* clue cells - bacteria adherent to vaginal epithelial cells
* oral or vaginal metronidazole (against anaerobes)
* Whiff-test - fishy odor worse with 10% KOH
189
Tx of enterococcus endocarditis?
MOA of Rx?
aminoglycoside (gentamicin)
bind 30S subunit causes genetic code misreading, inhibiting protein synthesis
190
recurrent infections of S. aureus coming up in abscesses is due to...
colonization of the anterior nares
191
HIV risk for infection when
* \<200
* Pneumocystis jiroveci
* Toxoplasma gondii
* tx- TMP-SMX
* \<100
* Histoplasma capsulatum
* \<50
* MAC - fluoroquinolones
* CMV - ganciclovir
* Cryptococcus neoformans
192
C. difficile has two toxins that act to create the pathogenesis of diseae. What are they?
How do they work?
* enterotoxin A and cytotoxin B (more virulent)
* bind R on intestinal mucosal cell and get internalized
* inactivates Rho-regulatory proteins (signal transduction) and actin cytoskeletal structure maintenance
* disrupts intercellular tight junctions
193
Rhabditiform larvae in the stool - pathogen?
What is their infectious form?
tx?
Strongyloides stercoralis
filariform larvae
ivermectin
194
burn pt, likely infectious pathogens?
g+ S. aureus and enterococcus
g- Pseudomonas, E. coli, Klebsiella, and Acinetobacter
195
1. broad based budding yeast?
2. dimorphic fungi, SW US, I/C pt?
3. India ink stain, meningitis in I/C?
4. R angle branching hyphae, does not grow on blood cultures?
1. blastomyces
2. coccidioides
3. cryptococcus
4. mucorales or rhizopus
196
How is resistance of mycobacterium to isoniazid established?
non-expression of catalase peroxidase enzyme or genetic modification of INH binding site on mycolic acid synthesis enzyme
197
What location is Plasmodium found where it is very resistant to chloroquine?
What drug should you rx?
Primaquine is required to tx what 2 strains?
Africa
rx atovaquone-proguanil
P. vivax and P. ovale (kill liver hypnozoites)
198
dengue virus description
What is a secondary infection due to and how may it present?
ssRNA (4 serotypes)
secondary infection d/t infection with different viral serotype and usually causes more severe illness (eg Dengue hemorrhagic fever)
199
Your pt is diagnosed with primary syphilis and you decide to tx with benzathine Pen G. A few hours later, acute febrile ssx develop.
Dx?
mechanism of illness?
Jarisch-Herxheimer reaction
Mech: abx for spirochete infection - causes rapid lysis of spirochetes, spilling bacterial lipoproteins into blood and triggering strong innate immune response
mostly self-limited
200
Where is HIV-2 endemic?
HIV-2, compared to HIV-1, has...
Dx of HIV-2 is suspected when...
West Africa
* lower viral loads
* less risk of transmission
* slower progression to AIDS
HIV tests are incongruent
201
What are the HIV genome structural genes?
What do they code for?
Then what happens?
gag, pol, env
code for polyproteins, then are cleaved by host or viral proteases into individual proteins of HIV virus
202
What could possibly occur if fetus is infected with rubella during the first trimester?
sensorineural deafness
cataracts
cardiac malformations (PDA)
203
3 antiviral drugs to treat HSV-2?
MOA?
acyclovir, valaciclovir, famciclovir (nucleoside analogs)
incorporated into newly replicating viral DNA and ultimately terminate viral DNA chain synthesis
204
splenic red pulp is important for what two things?
1. destroy abnormal or old RBCs while holding good cells in storage
2. clearance of circulating bacteria that becomes lodged in the cords
205
What about N. gonorrhoae lends itself to reinfection?
high antigenic variability of its surface molecules (eg porins, Opa proteins, LOS endotoxin), preventing formation of protective immunity allowing for reinfection
206
What is the tx of CMV?
MOA?
ganciclovir
competitively inhibit incorporation of dGTP by viral DNA polymerase
207
What is Caspofungin most active against?
It has limited or no activity against what?
* best: Candida and aspergillus
* none: cryptococcus
* limited: mucor and rhizopus
208
farmer with penetrating injury leading to gas in infected site, crepitus
pathogen?
other illness it can cause?
* clostridium perfringens
* late onset food poisoning s/p spore ingestion causing watery diarrhea
* gas gangrene = clostridium myonecrosis
209
high grade fever, HA, retro-orbital pain, bleeding from nose or purpura, macular rash, muscle and joint pain, 'break bone fever'; leukopenia, cytopenia, thrombopenia, increased LFTs
dengue hemorrhagic fever
210
pt receiving parenteral nutrition through central venous catheter have increased risk for...
which has what morphology?
candidemia
pseudohyphae with blastoconidia
211
MOA of caspofungin and other echinocandin antifungals
What is the major polysaccahharide component here?
suppress fungal wall cell synthesis by inhibiting glucan synthesis
1,3-beta-D-glucan
212
fungus in spherules?
where is it located?
sequelae of infection?
coccidiomycosis
SW US
meningitis and pna
213
UTI with Proteus will probably have..
why?
magnesium, ammonium, phosphate crystals in urine;
protease secreates urease, promoting alkalinization causing ppt of phosphate + carbonate and magnesium
leading to production of struvite kidney stome
214
an injury to a patient due to failure to follow evidence based best practice guidelines
preventable adverse event
215
unexpected occurrence involving death or serious physical or psychological injury
sentinel event
216
a medical error that is recognized before any harm is done to the patient
near miss
217
what cytokine is secreted by both Th1 and Th2 cells and promotes the growth and differentiation of bone marrow stem cells
IL-3
218
normal RBC mass and decrease in plasma volume will cause a ...
what could this be from?
relative erythrocytosis
aggressive diuretic therapy for heart failure exacerbation
219
marked erythrocytosis and more modest increase in granulocytes and platelets; low epo level along with increased RBC mass
Polycythemia vera
220
What is the apparent threshold for development of secondary erythrocytosis?
Sa \<92% / PaO2\<65
hypoxic erythrocytosis
221
How and where does the hormone leptin work in the brain?
acts on the arcuate nucleus of the hypothalamus to inhibit production of neuropeptide Y (decreasing appetite) and stimulate production of alpha-MSH (increasing satiety)
222
What does sunlight exposure catalyze in Vitamin D synthesis?
conversion of 7-dehycrocholesterol to cholecalciferol (vit D3) in the skin
223
What is the gene mutation in achondroplasia? What does this cuase?
FGFR3 usually limits chondrocyte proliferation during endochondral ossification
in this disease, FGFR3 becomes constitutively activated, causing exaggerated inhibition of chondrocyte proliferation that results in the characteristic bone shortening and craniofacial abnormalities
224
