uWorld 22 Flashcards

1
Q

what is the inheritance of hereditary spherocytosis

A

AD

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2
Q

RBC nuclear maturation defect due to defective DNA synthesis is seen in what

A

megaloblastic anemia (B12 or folate deficiency)

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3
Q

what kind of midline abdominal protrusion is seen in Downs Syndrome

A

uncomplicated umbilical hernia (incomplete closure of the umbilical cord)

duodenal atresia also seen (failure of recanalization that has bilious vomiting in first 24 hours of life)

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4
Q

what causes an uncomplicated umbilical hernia and what is seen in it

A

defect at linea alba covered by skin

reducible budge at umbilicus, notably with increased abdominal pressure (crying, passing bowel movements)

resolve spontaneously

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5
Q

uncomplicated umbilical hernia is associated with what conditions

A

down syndrome
hypothyroidism
Beckwith-Wiedemann snydrome (WT2 mutation- Wilms tumor, macroglossia, hemihypertrophy, organomegaly)

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6
Q

failure of extra embryonic gut to return to the abdominal cavity is seen in what condition(s)

A

omphalocele (midline herniation of abdominal contents contained within a thin, membranous sac)
gastroschisis (full thickness abdominal wall defect that presents as an evisceration of exposed abdominal contents at birth)

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7
Q

incomplete rotation of the midgut in utero often results in what

A

incomplete rotation of the midgut prior to physiological reduction into the abdominal cavity
alone asymptomatic but main complication is ISCHEMIA and subsequent small bowel NECROSIS due to VOLVULUS (twists and constricts the blood supply)

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8
Q

the normal distribution of individual observations of a variable (like blood folate levels) can be described how

A

mean and standard deviation

mean +/- (z-score)*SD
a z-score of 1.98 would cover 95% of all observations; 2.58 would cover 99% of all observations

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9
Q

what is the confidence interval

A

range of values within which one can be confident that the true mean of the underlying population falls

mean +/- (z-score)*SD/sqrt(n)

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10
Q

whats the difference b/w standard deviation and standard error

A

standard deviation: reflects spread of individual values in a normal distribution

standard error of the mean: reflects variability of means and helps estimate the true mean of the underlying population

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11
Q

what does acute humoral (B-cell) rejection cause in the pt

A

NECROTIZING VASCULITIS with a NEUTROPHILIC infiltrate

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12
Q

what reduces graft vs host disease

A

exact HLA matching

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13
Q

significant hypokalemia (like that caused by thiazide diuretics)

A

MUSCLE WEAKNESS
cramps
possible rhabdomyolysis

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14
Q

hypovolemia stimulates reabsorption of what in the proximal tubule and what does this cause

A

hyperuricemia

potentially precipitate a gout attack (acute monoarticular arthritis)

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15
Q

hypophosphatemia can cause what and is commonly seen in whom

A

muscle weakness and paralysis

seen in alcoholics

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16
Q

what is seen with acute hyponatremia

A

nausea
malaise
headache
CNS symptoms (altered mental status, seizures)

muscle cramps more common in chronic hyponatremia

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17
Q

oral aspiration lung abscesses is commonly seen in whom

A
loss of consciousness or DYSPHAGIA:
alcoholics
SEIZURE DISORDERS
drug overdose
prolonged anesthesia
severe neurologic disease

fever, night sweats, weight loss, and cough productive of FOUL-SMELLING SPUTUM (indicative of anaerobes)

often mixed aerobic and anaerobic oral flora:
Peptostreptococcus, Prevotella, Bacteroides, and Fusobacterium

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18
Q

what are the predisposing factors to lung abscesses as complication of bacterial pneumonia
what are the bugs that do it

A

immunosuppression, old age, underlying chronic lung disease

necrotizing pneumonias are usually nosocomial and caused by Staph Aureus, E Coli, Klebsiella pneumoniae, Pseudomonas aeruginosa

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19
Q

lung abscesses that develop in pts with septicemia or infectious endocarditis (hematogenous spread of infection to the lung)

A

multiple abscesses and mono microbial

staph and strep are common causative agents (also in penetrating trauma)

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20
Q

tobacco smoking compromises pulmonary defenses and predisposes patients to developing pneumonia from what pathogens

A

community acquired pneumonia
Step pnuemoniae
Mycoplasma Pneumoniae (both are less likely to cause lung abscess)

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21
Q

what are the most frequent cause of lung abscess

A
bacteria normally found in the oral cavity:
Peptosteptococcus
Prevotella
Bactericides
Fusobacterium

aspiration risk: alcoholism, drug abuse, seizure disorders, stroke, dementia

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22
Q

what is heterozygous familial hypercholesterolemia

A

AD LDL receptro defect that causes high LDL levels and increases the risk of PREMATURE ATHEROSCLEROSIS

homozygous is more severe form of disease: often present with coronary heart disease in childhood/adolescence

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23
Q

what are the steps of southern blotting

A
  1. DNA extraction form individuals cells
  2. RESTRICTION ENDONUCLEASE DIGESTION of the DNA sample into fragments
  3. gel electrophoresis to separate the various sizes of DNA fragments; larger fragments move slowly and shorter fragments faster
  4. DNA probe (a single-stranded segment of labeled DNA complementary to the gene of interest) to identify the target gene
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24
Q

what happens when allopurinol and azathioprine are used together

A

allopurinol blocks xanthine oxidase (TPMT) which degrades azathioprine to its inactive metabolites

azathioprine is then converted via HGPRT to its active metabolite (6-THIOGUANINE)

when known this can amplify the effect while decreasing dose of azathioprine
when unrecognized this can contribute to death nd opportunistic infections

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25
what is seen in asbestos-related plural disease
PLEURAL THICKENING CALCIFIED LESIONS (pleural plaques) of the parietal pleural /w 6th and 9th ribs benign PLEURAL EFFUSIONS found in posterolateral MIDLUNG Zones commonly 20 to 30 year latency between asbestos exposure and onset of symptoms
26
what is seen in asbestosis
slowly progressive, diffuse pulmonary fibrosis interstitial lung injury due to fiber inhalation usually in LOWER pulmonary ZONES and manifests radiographically as LINEAR INTERSTITIAL DENSITIES
27
what is seen in pulmonary berylliosis
closely resembles sarcoidosis (nodular infiltrates, enlarged lymph nodes, noncaseaseitng granulomas) not strongly associated with pleural plaques or effusinos
28
what is seen in coal workers pneumoconiosis
biologically as multiple discrete nodules (1-4mm), most prominent in the UPPER lung ZONES no plaques or effusions
29
nitrogen dioxide (NO2) is a toxic product of combustion that who is at risk for? and how does it resent
firefighters, welders, and farm silo workers are at risk | presents similar to asthma or chronic obstructive pulmonary disease and imaging may reveal pulmonary edema
30
what is seen in hypersensitivity pneumonitis
inhalation of organic dusts tends to result in DIFFUSE NODULAR INTERSTITIAL infiltrates on chest x-ray no plaques or nodules
31
what is seen in pulmonary silicosis
nodular densities | EGGSHELL calcification of the HILAR NODES are seen
32
when should children understand the concept of gender
age 3-4 sense of permanency of gender around 5-6 developmentally NORMAL to EXPLORE the world by engaging in ACTIVITIES associated with the OPPOSITE GENDER
33
what is gender DYSPHORIA
the PROLONGED and INTENSE feeling the person's gender DOES NOT MATCH one's ASSIGNED BIRTH SEX if strongly expressed, more likely to continue into puberty increased rates of psychiatric illness, including depression anxiety, and need monitoring and support dislike of own genitalia and persistent desires to be the opposite sex
34
where do stimulants like amphetamines and methylphenidate are first-line treatments for school-age children with ADHD
INCREASING RELEASE of NOREPI and DOPAMINE from vesicular storage sites and BLOCKING norepi and dopamine REUPTAKE at synapses in the PREFRONTAL CORTEX
35
drug transfusion reactions (anaphylaxis) are seen in what immunodeficiency
selective IgA deficiency
36
what are the clinical features and diagnostics for selective IgA deficiency
usually asymptomatic recurrent SINOPULMONARY and GI infections autoimmune disease (celiac) anaphylaxis during TRANSFUSIONS (from IgE antibodies to IgA aka anti-IgA antibodies) low or absent serum IgA levels normal IgG and IgM levles
37
what happens to people with C1 deficiency during transfusions
hereditary angioedema but do not have urticaria or wheezing like ppl with Ig-A deficiency
38
what is the MOA of terbinafine
inhibition of squalene epoxidase (and thus ergosterol synthesis) used to treat dermatophytosis drug tends to accumulate in skin and in appendages
39
low haptoglobin levels are a sign of what
hemolytic anemia also see increased direct bilirubin and lactate dehydrogenase
40
what are the signs of thrombocytopenia
easy bruisability petechiae mucocutaneous hemorrhage (recurrent epistaxis, gingival hemorrhage)
41
what does a platelet function analyzer (PFA-100) test monitor
the time needed for a patients blood to form a platelet-based hemostatic plug in an in vitro environment abnormal values seen in VON WILLEBRAND DISEASE, inherited/acquired platelet dysfunction (NSAID use), and THROMBOCYTOPENIA
42
what is the thrombin time and when is it increased
rate of conversion of fibrinogen to fibrin prolonged in pts with deficient or defective fibrinogen, can be congenital or acquired most common cause of dysfibrinogenemia is liver disease
43
what are the cardiac and smooth muscle effects of milrinone
PDE3 inhibitor cardiac muscle: positive INOTROPY smooth muscle: VASODILATION (arterial and venous)
44
what is hydrocephalus ex vacuo
normal ICP and increased dilation of ventricles secondary to cortical atrophy occurs most offend in elderly patients with dementia
45
what is seen in pseudotumor cerebri
elevated ICP and classical occurs in YOUNG women who are OVERWEIGHT thought to be related to cerebral venous outflow abnormalities due to elevated intracranial pressures
46
severe pharyngitis with exudates and cervical lymphadenopathy in a group of people with unknown vaccination status should raise suspicion for what
respiratory diphtheria infections toxin can cause MYOCARDITS and HEART FAILURE
47
how does the hyperammonemia occur in liver cirrhosis
increased levels of nitrogenous substances absorbed by the gut Gi bleeding or increased dietary protein causes increased nitrogen delivery to the gut in the form of hemoglobin, which is then converted to ammonia and absorbed into the bloodstream ammonia enters the liver through the portal vein and is detoxified to urea (but liver CANT DETOXIFY IT in failure)
48
what is used to lower the ammonia levels in hepatic encephalopathy
lactulose or RIFAXIMIN
49
accumulation of BUN is suggestive of what
renal failure heart failure dehydration Gi bleeding (in healthy patients, decreased in ppl with liver disease)
50
in hepatic encephalopathy what happens to neurotransmitter levels
increased inhibitory neurotransmission (GABA) decreased excitatory neurotransmitter relate (glutamate, catecholamines)
51
how does left ventricular preload reduction effect regurgitant flow
if degree of mitral valve incompetence is volume dependent it may DECREASE if non-volume-dependent causes of mitral regard (congenital, annular calcification) are not affected
52
what is an encapsulated gram negative bacilli that grows pink-colored mucoid colonies on MacConkey Agar (and thus is lactose fermenting) (typically causing right UPPER LOBE pneumonia in alcoholics and other immunocompromised)
Klebsiella pneumoniae characteristic mucoid growth on cloture thick, mucoid, blood-tinged sputum (CURRANT JELLY SPUTUM) lung tissue necrosis with early abscess formation right upper lobe b/c aspiration typically happen while sleeping
53
at what CD4 count are AIDs pts more susceptible to CMV, what is the most common finding associated with it
CD4 less than 100 | RETINITIS
54
what happens to the cardiac output and venous return curves in chronic anemia
increases in cardiac output in effort to meet the metabolic demands of the tissues (CO urge slope and max value increase) somewhat increase in venous return due to decreased blood viscosity (VR slope and y-int increase) both x intercepts stay the same looks the same as if you were to DECREASE TPR (EXERCISE, AV SHUNT)
55
what happens to the cardiac output and venous return curves in anaphylaxis
widespread venous and arteriolar dilation along with increased capillary permeability and third-spacing of glides serious DROP in VENOUS RETURN (down and leftward shift) cardiac contractility also increases as the body attempts to maintain blood pressure (slope and max value increase, x-int stays same)
56
what is the largest branch of the brachial plexus and where does it get its roots
RADIAL NERVE C5-T1 innervates EXTENSOR MUSCLES of upper limb BELOW SHOULDER sensory to skin of POSTERIOR ARM, FOREARM, and DORAL LATERAL HAND
57
MIDSHAFT HUMERUS break or penetrating stop wound will fuck up what nerve, what you gna see
RADIAL NERVE (courses through radial glove on the humerus) can also get fucked up during superficial course within AXILLA
58
patients with proximal radial neuropathy (like mid shaft humerus or axilla) typically have what
weakness during wrist and finger extension (wrist drop) and variable sensory loss of the posterior arm and forearm
59
weakness on thumb OPPOSITION, what nerve is fucked up
MEDIAN nerve
60
damage liming FINGER ABDUCTION and THUMB ADDUCTION, whats fucked up
ULNAR nerve
61
what is rasburicase, what is it used for
recombinant version of URATE OXIDASE (enzyme in many mammals but not humans) catalyzes conversion of URIC ACID to ALLANTOIN (5-10 times more soluble) degrades uric acid formation doesn't stop its formation use it in tumor lysis syndrome or any state of hyperuricemia
62
what is seen in tumor lysis syndrome
``` potassium release (fatal ARRYTHMIAS) phosphorous release nucleic acids (uric acid- gout or stones) ```
63
how does MESNA work
supplies THIOL group that inactivates the toxic metabolite ACROLEIN (of cyclophosphamide or ifosfamide) prevents hemorrhagic cystitis
64
what are phosphate binders (sevelamer) used for
manage hyperphosphatemia in patients with chronic kidney disease
65
potassium exchange resins (sodium polystyrene sulfonate) do what
help excrete potassium form the body (through stools) by exchanging it with sodium
66
what provides blood to the INFERIOR (DIAPHRAGMATIC) surface of the heart (in most individuals) inferior surface is both left (2/3s) and right (1/3) ventricles
most peeps are RIGHT DOMINANT heart so the POSTERIOR DESCENDING ARTERY (PDA) comes off the RIGHT CORONARY ARTERY PAD runs down the posterior interventircular groove and supplies the POSTERIOR 1/3 go of the IV SEPTUM and most of INFERIOR WALL of the LEFT VENTRICLE
67
what does the LAD supply
anterior 2/3 of IV septum (septal branches) anterior wall of left ventricle (diagonal branches) part of he anterior papillary muscle
68
what does the left circumflex supply
lateral and posterior superior walls of the left ventricle via obtuse marginal branches
69
what is the right marginal branch of the right coronary artery
supples wall of the right ventricle and may provide collateral circulation in pts with LAD occlusion
70
what is dobutamine
beta-adrenergic agonist (B1 over B2) POSITIVE INOTROPIC EFFECT- ↑ contractility leading to ↑ CO and ↓ LV filling pressures weakly POSITIVE CHRONOTROPIC EFFECT- ↑ HR (↑ O2 CONSUMPTION, ↓ diastolic filling time) VASODILATION used in refractory heart failure associated with severe LV systolic dysfunction and cariogenic shock
71
why do infections with Neisseria gonorrhoeae not appear to to provide lasting protective immunity to re-infection
ability of many gonococcal surface antigens to undergo high frequency of ANTIGENIC VARIATION IgA and IgG antibodies formed are either highly strain specific or poorly active
72
HbS and HbC are caused by what kind of mutations
MISSENCE mutation- single base substation results in a codon that codes for diff amino acid glutamate to valine and lysine (respectively)- causes a decrease in negative charge on the Hb molecule
73
HbH (alpha thalassemia with beta tetramers) is caused by what kind of mutation
FRAMESHIFT deletion or insertion of base paris that are NOT multiple of 3 alters the reading frame of the code reusing in nonfunctional proteins duschene muscular dystrophy is also frameshift (or deletions)
74
compare HbS, HbC, and HbA speed on electrophoresis
HbA is fastest, then HbS, then HbC is slowest
75
what does hypocapneia do the the brain blood flow
cerebral vasoCONSTRICTION | ↓ cerebral blood flow
76
what are the signs of TCA overdose and what is used to treat it
mental status change (drowsiness, delirium, coma) seizures, resp ↓ sinus tachycardia, hypotension prolonged PR/QRS/QT intervals DRY MOUTH, BLURRED VISION, DILATED PUPILS URINARY RETENSION, FLUSHING, HYPERTHERMIA SODIUM BICARBONATE corrects the cardiac abnormalities b/c TCAs block CARDIAC FAST SODIUM CHANNELS
77
if you are shown gel electrophoresis of DNA SIZE with bp given and they are different by say 28 and it asks what is responsible for the condition (mutations wise), what is it
FRAMESHIFT b/c the difference is not by a multiple of 3 nonsense mutation would not alter the size of the mRNA it owed only alter the size of the protein
78
what drug can be used (and enzyme inhibited) to prevent recurrent adenomas in someone with large adenomatous polyps with severe dysplasia in the sigmoid colon
celecoxib blocking CYCLOOXYRGENASE-2 this stops the hyper proliferative epithelium phase of the ADENOMA-CARCINOMA sequence (APC → methylation abnormalities, COX-2 over expression → KRAS, DCC, p53 activation → further accumulation of genetic abnormalities)