uWorld 22 Flashcards
what is the inheritance of hereditary spherocytosis
AD
RBC nuclear maturation defect due to defective DNA synthesis is seen in what
megaloblastic anemia (B12 or folate deficiency)
what kind of midline abdominal protrusion is seen in Downs Syndrome
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)
what causes an uncomplicated umbilical hernia and what is seen in it
defect at linea alba covered by skin
reducible budge at umbilicus, notably with increased abdominal pressure (crying, passing bowel movements)
resolve spontaneously
uncomplicated umbilical hernia is associated with what conditions
down syndrome
hypothyroidism
Beckwith-Wiedemann snydrome (WT2 mutation- Wilms tumor, macroglossia, hemihypertrophy, organomegaly)
failure of extra embryonic gut to return to the abdominal cavity is seen in what condition(s)
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)
incomplete rotation of the midgut in utero often results in what
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)
the normal distribution of individual observations of a variable (like blood folate levels) can be described how
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
what is the confidence interval
range of values within which one can be confident that the true mean of the underlying population falls
mean +/- (z-score)*SD/sqrt(n)
whats the difference b/w standard deviation and standard error
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
what does acute humoral (B-cell) rejection cause in the pt
NECROTIZING VASCULITIS with a NEUTROPHILIC infiltrate
what reduces graft vs host disease
exact HLA matching
significant hypokalemia (like that caused by thiazide diuretics)
MUSCLE WEAKNESS
cramps
possible rhabdomyolysis
hypovolemia stimulates reabsorption of what in the proximal tubule and what does this cause
hyperuricemia
potentially precipitate a gout attack (acute monoarticular arthritis)
hypophosphatemia can cause what and is commonly seen in whom
muscle weakness and paralysis
seen in alcoholics
what is seen with acute hyponatremia
nausea
malaise
headache
CNS symptoms (altered mental status, seizures)
muscle cramps more common in chronic hyponatremia
oral aspiration lung abscesses is commonly seen in whom
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
what are the predisposing factors to lung abscesses as complication of bacterial pneumonia
what are the bugs that do it
immunosuppression, old age, underlying chronic lung disease
necrotizing pneumonias are usually nosocomial and caused by Staph Aureus, E Coli, Klebsiella pneumoniae, Pseudomonas aeruginosa
lung abscesses that develop in pts with septicemia or infectious endocarditis (hematogenous spread of infection to the lung)
multiple abscesses and mono microbial
staph and strep are common causative agents (also in penetrating trauma)
tobacco smoking compromises pulmonary defenses and predisposes patients to developing pneumonia from what pathogens
community acquired pneumonia
Step pnuemoniae
Mycoplasma Pneumoniae (both are less likely to cause lung abscess)
what are the most frequent cause of lung abscess
bacteria normally found in the oral cavity: Peptosteptococcus Prevotella Bactericides Fusobacterium
aspiration risk: alcoholism, drug abuse, seizure disorders, stroke, dementia
what is heterozygous familial hypercholesterolemia
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
what are the steps of southern blotting
- DNA extraction form individuals cells
- RESTRICTION ENDONUCLEASE DIGESTION of the DNA sample into fragments
- gel electrophoresis to separate the various sizes of DNA fragments; larger fragments move slowly and shorter fragments faster
- DNA probe (a single-stranded segment of labeled DNA complementary to the gene of interest) to identify the target gene
what happens when allopurinol and azathioprine are used together
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
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
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
what is seen in pulmonary berylliosis
closely resembles sarcoidosis (nodular infiltrates, enlarged lymph nodes, noncaseaseitng granulomas)
not strongly associated with pleural plaques or effusinos
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
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
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
what is seen in pulmonary silicosis
nodular densities
EGGSHELL calcification of the HILAR NODES are seen
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
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
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
drug transfusion reactions (anaphylaxis) are seen in what immunodeficiency
selective IgA deficiency
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
what happens to people with C1 deficiency during transfusions
hereditary angioedema but do not have urticaria or wheezing like ppl with Ig-A deficiency
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
low haptoglobin levels are a sign of what
hemolytic anemia
also see increased direct bilirubin and lactate dehydrogenase
what are the signs of thrombocytopenia
easy bruisability
petechiae
mucocutaneous hemorrhage (recurrent epistaxis, gingival hemorrhage)
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
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
what are the cardiac and smooth muscle effects of milrinone
PDE3 inhibitor
cardiac muscle: positive INOTROPY
smooth muscle: VASODILATION (arterial and venous)
what is hydrocephalus ex vacuo
normal ICP and increased dilation of ventricles secondary to cortical atrophy
occurs most offend in elderly patients with dementia
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
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
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)
what is used to lower the ammonia levels in hepatic encephalopathy
lactulose or RIFAXIMIN
accumulation of BUN is suggestive of what
renal failure
heart failure
dehydration
Gi bleeding (in healthy patients, decreased in ppl with liver disease)
in hepatic encephalopathy what happens to neurotransmitter levels
increased inhibitory neurotransmission (GABA)
decreased excitatory neurotransmitter relate (glutamate, catecholamines)
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
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
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
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)
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)
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
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
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
weakness on thumb OPPOSITION, what nerve is fucked up
MEDIAN nerve
damage liming FINGER ABDUCTION and THUMB ADDUCTION, whats fucked up
ULNAR nerve
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
what is seen in tumor lysis syndrome
potassium release (fatal ARRYTHMIAS) phosphorous release nucleic acids (uric acid- gout or stones)
how does MESNA work
supplies THIOL group that inactivates the toxic metabolite ACROLEIN (of cyclophosphamide or ifosfamide)
prevents hemorrhagic cystitis
what are phosphate binders (sevelamer) used for
manage hyperphosphatemia in patients with chronic kidney disease
potassium exchange resins (sodium polystyrene sulfonate) do what
help excrete potassium form the body (through stools) by exchanging it with sodium
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
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
what does the left circumflex supply
lateral and posterior superior walls of the left ventricle via obtuse marginal branches
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
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
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
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
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)
compare HbS, HbC, and HbA speed on electrophoresis
HbA is fastest, then HbS, then HbC is slowest
what does hypocapneia do the the brain blood flow
cerebral vasoCONSTRICTION
↓ cerebral blood flow
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
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
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)
