UWORLD questions brain scape Flashcards
1
Q
Cryptococcus neoformans is a yeast that has what kind of capsule?
A
antiphagocytic polysaccharide capsule.
2
Q
what stain can identify the yeast form of C. neoformans
A
methanamine silver stain. Seen in tissues as round cells with narrow based buds
3
Q
how does the polysaccharide capsule appear on india ink vs mucicarmine
A
india ink: capsule appear as a clear,unstained zone. Mucicarmine stains red !!! Look at powerpoint.
4
Q
immigrant ASIA, intermittent abd cramps. Multiple respiratory infections over past 2 years, persistent cough? What will be seen in stool
A
rhabditiform larvae (strongyloidiasis) can molt directly into filariform larva –> autoinfection. only eggs and adult parasties are seen in intestinal biopsies. Symp: intermittent gastrointestinal or pulmonary symptoms. Pruritic, erythematous, linear streaks (larva currens) may occur on thighs and butt as larva migrate away from perianal region.
5
Q
the vagus nerve when stimulated release ACH –> bronchoconstriction. If shown a chart that shows a asthma drug working to reverse the irritant induced bronchoconstriction. Which drug is it?
A
ipratropium or tiotropium: they competitively BLOCK muscarinic receptors –> preventing bronchoconstriction.
6
Q
a pt with dermatomyositis, whats associated with it?
A
it may occur as a paraneoplastic syndrome, of an underlying malignancy, most commonly: ovarian (ovarian adenocarcinoma), lung, colorectal, and non-hodgkin lymphoma.
7
Q
21 yo co of repeated palpiations that start and stop abruptly. You suspect there is abnormal conduction pathway in this pts heart that bypasses the ATRIOVENTRICULAR NODE. What part of the ECG is most likely affected?
A
pt has wolf-parkinson-white traid image showing the ecg with arrow under PR interval (delta wave = shortened PR interval and widened QRS) the recurrent temporary tachyarrhythmias are due to an atrioventricular re-entry circuit, involing the AV node and the accessory pathway.
8
Q
a 22yo pt with hx of mitral valve prolapse comes to ER with intermittent fever and chills over past few days. Last week she had a dental cleaning. Physical exam reveals a nonejection mid systolic click followed by a late systolic murmur best heard at apex. blood culture show gram + bacteria that synthesize DEXTRANS from sucrose. WOTF would be the most likely adherence site for these bacteria?
A
virdians group strept. S.sanguinis - makes dextrans, which bind to fibirn-platelet aggregates on damaged heart valves. (most common mitral)
9
Q
if you give someone desmopressin (ADH analog) with central Diabete s insipitis their polyuria resolves. Vasopresin produces V2 receptor -mediated inc in water permeability w/in the corticol and medullary collecting duct. Renal clearance of what substances would decrease the most after this injection?
A
UREA. Bc vasopression (ADH) also activates urea transporters in the medullary collecting duct (imperable in the cortical CD), increasing the urea reabsorption and dec renal urea clearance.this passive reabsorption of urea into the medullary intersitium –> inc in medularry osmotic gradient allow production of maximally concentrated urine.
10
Q
viridans strept synthesize DEXTRANS from sucrose that facilitate strepts adherence to?
A
fibrin and platelets
11
Q
bacteria of lungtissue fails to decolorize w/ hydrochloric acid and alcohol after staining carbofuschin. WOTF cell wall components is responsble?
A
mycolic acid. (acid fast stain for mycobacteria) note the smear is first treated with aniline dye (carbofuchsin)
12
Q
tx of oral candidiasis
A
nystatin, or fluconazole, or caspofungin
13
Q
Calcium oxalate kidney stone. What med is most likely to precent recurrent stone formation in this patient
A
HYPERcalciuria is a risk factor for calcium stone. hydrocholorthiazide (thiazides) help by dec urine Ca excretion. They increase ca reabsorption through 2 mechanisms. 1. Inhibition of the Na/Cl cotransporter ( on the apical sided the DC tubule cells decreases intracellular NA concentrations. this activates the basolateral NA/Ca antiporter, which pumps NA into cells in exchange for Ca. resulting in dec intracellular Ca concentrations enhancing luminal Ca reabsorption across the apical membrane 2. hypovolemia induced by thiazides (inc Na and H20) reabsorption in proximal tubule, leading to passive inc in paracellular Ca reabsorption
14
Q
duodenal atresia (presents 1-2 days after birth, billious voting/distended abdomen and duodenum on X ray) what is the mechanism for development?
A
failure of gut recanalization.
15
Q
Delayed passage of meconium, abdominal distension and bilious emesis. Whats the disease and cause of it?
A
hirschsprung disease, caused by failure of neural crest cell migration in the gut causes AGANGLIONIC sigmoid colon/rectum.
16
Q
painless lower GI bleeding without emesis. Caused by the omphalomesenteric duct connects the midgut lumen w/ the yolk sac which failured to obliterate causing two things
A
vitelline fistula (complete failure) or a meckel diverticulum (partial failure).
17
Q
mid\gut malrotation caused by incomplete counterclockwise rot (180) can lead to cecum will be in RUQ and ladd (fibrous) bands connect the retroperitoneum in the RLQ to the right colon cecum by passing over the duodenum causing intestinal obstruction (bilious emesis during the first days of life). what embyonic process failed causing this?
A
midgut rotation around the superior mesenteric artery causing midgut volvulus.
18
Q
first line pharmacological tx for moderate to severe alcohol use disorder?
A
opiod antagonist NALTREXONE (Mu-opioid receptor blockade) its initiated while the patient is still drinking bc it blocks the rewarding and reinforcing effects of alcohol. This drug reduces craving!
19
Q
medications used to tx alcohol dependence?
A
natrexone, disulfiram (in pts that are abstinence bc it inhibits aldehyde dehydrogenase thus when alcohol is ingested it causes adverse effects).Acamprosate
20
Q
tetanus toxoid inactive vaccine - initiates what kind of immune response
A
humoral immunity: circulating antibodies that\ neutralize bacterial products
21
Q
a pt is experience unillateral vesicular rash single dermatome is present on chest. (herpes zoster) wotf is the pt most likely to suffer from within the next 6 months? A. recurrent skin rash, or B. persistent local pain?
A
persistent local pain (postherpetic neuralgia. “PHN”) often last for several months. Herpes zoster (occurs when latent VZV infection is reactivated within a single dorsal root sensory ganglion. Does not reoccur bc not herpes simplex virus.
22
Q
what are the two preferred diagnostic test for DM
A
HbA1C and fasting blood glucose level! Not oral glucose tolerance test (preferred in gestational and cystic fibrosis diabetes)
23
Q
why does epinephrine not increase renal BF like dopamine?
A
due to the lack of D1 receptor stimulation. Dopamine at low dose stimulates D1 receptors in renal vasculature and tubules inducing an inc in Renal blood flow, GFR, and NA excretion.
24
Q
what does dopamine do when given in high doses in reference to Blood flow
A
it stimulates B1 adrenergic receptors in heart, –> inc cardiac contractility, HR, and SBP. At higher end of the dose range, stimulation of a1 receptors in systemic vasculature –> vasoconstriction –> dec CO output do to inc afterload.
25
elderly pt with diabetes and has malignant otitis externa (granulaiton tissue seen in the ear canal.
pseudomonas aeruginosa (nonlactose-fermenting, oxidase positive, motile gram negative rod) this is the most common cause of MOE in elderly diabetic patients
26
where does the median nerve travel bw in the forearm.
bw the flexor digitorum superficialis and flexor digitorum profundus
27
4 yo girl. Abd pain, blind pouch connected to ileum. Under microscopy, it demonstrates pancreatic acini in the mucosa. This finding best described as?
Ectopy. (microscopy and functionally normal cells/tissues found in an abnormal loction due to embryonic maldevelopment). Patient had meckles diverticulum.
28
a pt with temporomandibular disorder. The motor and sensory components to this disorder. What nerve is responsible for the motor fibers to the tensor tympani causing the hearing probs?
mandibular nerve. Largest branch of the trigeminal nerve contains both motor and sensory components. The motor fibers innvervate the muscles of mastication, muscles of the floor of the mouth ( mylohyoid) tensor veli palatini, and the tensor tympani in the middle ear. thus if the pt is having both jaw pain and otologic symptoms its mandibular.
29
the maxillary branch of trigeminal supplies?
mainly sensory fibers from the cheek, nares, upper lip and teeth., the pharyngeal palate and maxillary sinuses
30
surge in anti-HBs and anti-HBc IgG, and possible anti-HBe represents?
had acute hep B and recovered successfully
31
surge in only anti-HBs?
immunity to hep b due to vaccinations
32
why can niacin cause gout?
it can dec renal excretion of uric acid --\> inc blood levels and an inc risk for acute gouty arthritis.
33
a pt with graves disease develops filtrative ophthalmopathy (due to glycosaminoglycans produced by the infiltrating Th1 cells cytokine release. What drug is used to tx this patients ocular symptoms
glucocorticoids (inflammatory infiltration.) don’t get tricked by reduced iodine organification (due to inhibition of thyroid peroxidase via methimazole, ,or ptu)
34
what disorder should you avoid copper containing products due to associated risk w/ (liver failure, movement abnormalities, and psychiatric symptoms)
wilsons
35
DNA repair disorders (ataxia-telangiectasia and xeroderma pigmentosum) should avoid
ionizing radiation.
36
which histone is found outside the core of histones to help promote chromatin compaction?
H1
37
what are the 4 mediators that attract/activate neutrophils?
Leukotriene B4!, C5A, IL8, bacterial products.
38
methimazole moa?
inhibits thyroid peroxidase thus inhibiting iodine organification and coupling of iodotyrosines.
39
propythiuracil moa?
inhibits thyroid peroxidase and 5-deiodinase preventing peripheral conversion of T4 to active T3
40
embryology of kidney. Metanephric mesoderm/mesenchyme (blastema) develop into?
everything bw glomerulus -- Distal convoluted tubue.
41
what does the metanephric diverticulum (ureteric bud) form
ureter, pelvises, calyces, colleccting ducts!
42
Cryptococcus neoformans budding yeast w/ thick capsules. Symptomatic infection w/ this organism most commonly manifest as?
meningoencephalitis. A lung infect does occur first, however its usually asymptomatic
43
C. neoformans have round budding yeasts have peripheral clearings or halos, due to their thick \_\_\_\_\_\_\_\_\_\_
polysaccharide capsules
44
what cuases comedonal and inflamatory nodular eruptions (ACNE)
methyltestosterone (androgens stimulate follicular epidermal hyperproliferation and excessive sebum production --\> promoting acne. Anabolic steriod misuse is known to cause acne in atheletes. (note excessive perspiration doesn’t cause acne)
45
during a midline episiotomy (vertical incision from posterior vagina opening, through the vag/subvaginal mucosa and to the\_\_\_\_\_\_\_\_\_\_\_\_?)
perineal body. Which is essential to the integrity of the pelvic floor.this is the tendinous center point of the perineum. (separates the urogenital and anal triangles)
46
what would be cut if you did a mediolateral episiotomy?
transverse perineal muscle.
47
immediately prior to delivery, estrogen stimulates upregulation of ? Leading to? It also increases expression of ______ receptors
gap junctions ( aggregated connexin! Proteins that allow passage of ions bw myometrial cells) bw individual myometrial smooth m cells. This inc in gap junction density at delivery heightens myometrial excitability. Also inc expression of uterotonic (oxytocin) receptors
48
antibodies against desmoglein, a cadherin protein for desmosomes are found in?
pemphigus vulgaris
49
antibodies to hemidesmosomes proteins causes
bullous pemphigoid and pemphigoid gestationis.
50
hyaline, acellular deposted composed of plasma proteins in renal disease
diabetic nephropathy (kimmelstiel-wilson nodules)
51
what stimulates the adrenal medulla (histology slide) to release hormones?
acetylcholine (released by PREganglionic sympathetic neurons) --\>stimulating medullary chromaffin cells (modified POSTganglionic sympathetic neurons0 --\> release epinephrine (80%) and nor epi (20%)
52
Zona glomerulosa (rounded or arched clusters that secrete?
mineralocorticoid hormones (aldosterone)
53
zona fasciculata (foamy appearing cells in columns secrete?
glucocorticoid (primarily cortisol)
54
zona reticularis (basophilic cells in anastomosing cords) that secrete?
androgens.
55
penicillins and cephalosporins funcdtion by irreversibly binding to penicillin binding proteins. Thus when subject to electrophoresis what would be bound to ceftriaxone?
tanspeptidases (are one form of PBP that function to cross link peptidoglycan binding proteins) thus cephalosporin "ceftriaxone" inhibit transpeptidase --\> cell wall instability and bacteriolysis.
56
digoxin
inhibition of Na K ATPase pump leading to increased parasympathetic tone leading to inhibition of atrioventricular AV nodal condunction
57
pt on a antipsychotic block D2 receptors in the 4 dopaminergic pathways (mesolimbic system (for schizo) side effect though is that since it blocks D2 In the _________ pathway, thus disinhibiting the tonic inhibition of prolaction secretion.
tuberoinfundibular pathway. (not the neurons in the arcuate nucleus in the hypothalamus secrete dopamine (prolactin-inhibiting factor.
58
blanching of a vein into which NE is being infused and induration and pallor of the surround tissue. Resulting in (alpha adrenergic) vasoconstriction which can leadto tissue necrosis. Tissue necrosis is best prevented by?
local injection of an alpha 1 blocking drug (pehntolamine.
59
pt c.o. of ringing in ear (tinnitus), recurrent spinning episodes (vertigo), sometimes earfulness/pain, unilateral sensorineural hearing loss. Diagnosis and cause?
menieres diseae of the (inner ear) cause inc pressure and volume of endolymph in inner ear (endolymphatic hydrops
60
brief episodes of dizziness spinning brought on by head movement , no auditory symp
BPPV, cause: otoliths in semicurcular canals
61
single episodeof severe vertig,N/Vthat last days and no hearing loss. Diagnosis and cause
vestibular neuritis (labyrinths) cause inflammation of verstibular nerve (labyrinth) post viral or viral.
62
a person with sarcodosis: wotf cells and cell products contribute to the pathology?
must know that granuloma formation is a manifestation of cell mediated immunity driven by Th1 type CD+ helper T cells, particularly IL-2 and interferon gamma which stimulates Th1 cell proliferatioin and macrophage activation
63
Th2 tpe CD4 helper T cell predominatly drives what immune response. And promotes?
humoral immune responses: Th2 type CD4 helper T cells --\> IL-4 which promotes IgE antibody product by B-cells , and IL5.which promotes the production and activation of eosinophil and B cell synthesis of IgA
64
during peak exercise what do you expect your labs to be in terms of o2 co2, ph
inc Co2 product from skeletal muscles --\> inc PCO2 mixed venous blood. no change in PaO2 or PaCO2, pH dec.
65
secretin (released from S cells in duodenum) stimulates? To secrete
INCREASE pancreatic HCO3- and dec gastric acid secretion and inc bile secretion
66
elderly women on Tea and Toast diet. Presents with easily bleeding gums brushing teeth, swollen gingiva that bleed on probing, image of perifollicular hemorrhages and coiled corkscrew hair). What hypoactive enzyme is causing this? And where
impaired collagen synthesis from vit C def (scurvy). Hydroxlation of proline and lysine in the RER.
67
the greastest amount of H20 reabsorbed by the kidney occurs where?
highest in PCT (60%)and second highest in descending limb of henle loop.
68
if fertilization and implantation occurs, when would B-hCG level first be detectable in serum?
8 days after fertilization.
69
how many days after fertilization does the blastocyst implant ?
6 days
70
pt that has coryneabacterium diptheriae the only tx is?
passive immunization (diptheria antitoxin) then penicillin or erythromycin, then DTP vaccine.
71
DNA methylation to nucleotide residues (adenine and cytosine) by DNA methyltransferase) uses SAM as the methyl group donor is seen in which genetic process?
imprinting .
72
a pt who receives the equivalent of more than 1 body blood volume (5-6 L) of whole blood or RBC transfusion over a period of 24 hrs may develop elevated ? That can cause what?
citrate --\> hypocalcemia via chelating the calcium.
73
HF symptoms.
exertional dyspnea and fatigue (caused by inability to inc CO) and orthopnea (due to elevated pulm circulation pressure and the resulting Pulm edema)
74
on a left heart cath showing an excessive rise in left atrial systolic pressure, is a characteristic finding for?
mitral regurgitation.
75
\_\_\_ tends to elevate left Ventricular diastolic pressure, and dec aortic DP, due to?
aortic regurg. Regurgitant flow from aorta to left vent
76
\_\_\_\_\_ causes an abnormal pressure gradient to form acorss aortic valve. Causing left vent Systolic pressure higher than aortic systolic pressure
aortic stenosis
77
\_\_\_\_ inc left atrial pressure during diastole (NOT systole) due to primary obstruction of left vent filling\>
mitral stenosis.
78
goat wool processing center, fever chest pain, hemoptysis, chest xray widened mediastinum. Large gram + rods that form medusa head colonies on media. This bacteria porduces an?
antiphagocytic capsule contain D-glutamate (not polysaccharide!!!)
79
the most common site of nerve compression in a pt with common peroneal (fibular) nerve leading to weakness on dorsiflexion (foot drop) and everson, impaired sensation over the lat shin and dorsal foot. is most likely compressed where?
fibular neck (because it raps around here and then divides into the deep peroneal nerve and supericial nerve.
80
which nerve gives off sensory branches to the dorsum of the foot and lateral shin?
superificial peroneal nerve
81
what provides sensation only to the webspace bw the first and second toes?
deep peroneal nerve.
82
homocystinuria occurs from genetic defect in cystathionine beta-synthase enzyme causing occurrence of muiltiple seemingly unrelated phenotypic manifestations in different organs as a result from a single genetic defect. This genetic defect is called?
pleiotropy.
83
pt with niemann-picks disease. What substrate will be accumulated (note start at 5 months like tay sachs but said hepatosplenomegaly)
sphingomyelin
84
the _______ contains ribosomal DNAcoding for ribosomal RNA (rRNA), components as well as new transcribed rRNA in associated with Ribosomal proteins that are translated in the cytoplasm from mRNA.
Nucleolus (be able to recognize on EM) the primary func: synthesis and assembly of immature 60s and 40s ribosomal subunits that are exported from nucleus to fully mature in the cytoplasm.
85
1 wk old boy with parathyroid and thymic hypoplasia resulting in hypocalcemia and T cell deficiency. What is the cause of this?
maldevelopment of the 3rd (inf parathyroid and thymus) and 4th (sup parathyroid) pharyngeal/branchial pouches.
86
hypopituitarism, hydrocephalus, diabetes insipidus, no hypocalcemia. Child. What embryologic structure is effect and what is the cause of symptoms
craniopharyngiomas arising from the remnants of the Rathke pouch. (invaginated oral ectoderm that eventually develops into anterior pituitary)
87
failure of the anterior neuropore to close leads to neural tube defects such as?
anencephaly.
88
insulin increases or decreases renal absorption of 1. sodium 2. glucose
1. inc Na reabsorption. 2. no effect on glucose.
89
what is the most useful measure for assessing the degree of mitral stenosis.
S2 - to opening snap time interval.
90
pts on carbamazepine for seizures since a child. Presents w/ dizziness and mild confusion over a week. Labs: low serum Na concentration its determined this condition is caused by a inc release of a hormone that is co-secreted with neophysins. if given a picture of the hypothalamus. Label where this hormone is secreted.
pt has SIADH due to carbamazepine, (or cyclophosphamide or SSRI). Secreted from posterior pituitary. ADH and oxytocin are synthesized w;in magnocellular neurons found in supraoptic and paraventricular nuceli in hypothalamus. They are packaged into vesicles with neurophysins (involved in posttranslational hormone processing adn stabilization during axonal gtransport)
91
pt co solid food dysphagia sensation of food getting stuck in mid thorax. Barium esophagram: extrinsic compression on the mid esophagus.pt had Rheumatic heart disease a little while back. Enlargement of what structure is causing the dysphagia?
rheumatic heart disease --\> mitral stenosis/ regurg (palpitations, exertional dyspnea). --\> left atrial enlargement (posterior surface of heart) which lies directly over esophagus causing external compression of mid esophagus with dysphagia (cardiovascular dysphagia)
92
a pt that is overdosing on warfarin (life threatening bleeds) What the FASTEST reversal of warfarins effects?
fresh forzen plasma (not vit K bc it takes time)
93
filures of the rostral neuropore to close --\> anencephaly, whereas impaired closure of the caudal neuropore casues?
Spina Bifida.
94
if either neuropore does not fuse an opening persists bw the neural tube and amniotic cavity that allows leadage of ___________ and \_\_\_\_\_\_\_\_- into the amniotic fluid. Thus the detection of either of these used as prenatal screening of NTD.
(AChE) acetylcholinesterase and Alpha-fetoprotein (AFP) which can cross the placenta and is detectable in the maternal serum. ( so a pregnant women that undergoes an amniocentesis showing inc AChE are suggest failure of what? FUSION of the EDGES of the NEURAL PLATE.
95
Which one would increased in obstructive lung disease A. TLC / RV ratio, B. RV / TLC ratio?
RV/TLC (bc RV = lung volume that remains after max expiration, the RV inc in COPD.) note its not TLC/RV, bc the TLC does inc in Obstructive lung disease, but it does so primarily through expansion of the RV compartment.
96
a pt with MS has urge incontinence and urinary frequency in the setting of overactive or spastic bladder due to the presence of umn lesion in Spinal cord. What would you expect on urodynamic studies?
bladder is hypertonia. Bc there is little or no residual urine volume after emptying as bladder contractility is normal but distensibility Is poor. The bladder does not distend/relax due to loss of descending inhibitory control from the UMN
97
why does the H. influ B vaccine contain both capsular polysaccharide of Hib and Conjugated tetanus toxoid.
Elicits T cell Dependent immune response (the conjugated carrier protein (tetanus toxoid[TTT] portien or out membrane protein [OMP] of N. meningitidiis) causes T cell mediated immune response) thus leading to long term immunity through productio of memory B lymphocytes
98
what Benzo would you give to minimize daytime side effects (fatigue, impaired judgement)?
short (triazolam, oxazepam, midazolam or intermediate -acting (lorazepam, alprazolam, temazepam) given before bed.
99
the most common congenital cardiac malformation in Turner syndrome?
Bicuspid aortic valve (nonstenotic bicuspid aortic valve manifests w/ an aortic ejection sound = (early systolic, high frequency click heard over the Right second interspace) note!!! It can cooccur with aortic coarctation.
100
reperfusion injury (question said thrombus extracted followed by rapid surge of serum creatine kinase levels) this surge is best explained by?
Cell membrane damage. (enzyme leaks across damaged cell membranes into circulation)
101
Intraventricular hemorrhage (IVH) is a common complication of prematurity. Occurs Most frequently before 32 weeks gestation and/or with birth weight \< 1500 g. almost always occurs w/in first 5 postnatal days. Can present silent or altered consciousness, hypotonia, and decreased spontaneous movments. symptoms of catastrophic bleeding : bulding anterior fontanelles, hypotension, decerebrate posturing, seizures, irregular respirations, coma. blood found in the lateral ventricles. where do most IVH originate from?
germinal matrix - highly vascularized layer in the subventricular zone from which neurons and glial cells migrate out during brain development. The matrix contains numerous thin walled vessels lacking the glial fibers for support thus inc risk of hemorrhage.
102
describe the amount of K+ in the tublar fluid as it flows along the nephron in comparison to the filtered potassium load (during high dietary K intake). Bowmans capsure\_\_\_\_, proximal tubule\_\_\_\_, Thick Ascending limb of henle \_\_\_\_\_\_\_, Collecting duct\_\_\_
Bowmans capsule: fluid = 100%. Proximal tubule: TF 35%, (65% filtered), Thick ascend: TF 10% (25-30% filtered) collecting duct: TF 110%. (the principal and Alpha-intercalated cells of the late distal and cortical collecting tubules are the primary mediators of K regulation. during normal or increased K load stimulate principle cells to secrete K through apical K channels --\> amount of K in CT to exceed filtered load. (not this question)Hypokalmeia --\> stimulates reabsorption of K via apically located H/K-ATPases on A-intercalated cells.
103
maternal ________ and __________ are the strongest risk factors for infant infection with HBV during delivery?
maternal viral load and HBeAg
104
once an infant is infected with HBV they develop high levels of Viral load and HbeAg. Despite this high replication the infants enter an _____________ phase of chronic HBV infection which they are asymptomatic and have normal / mild elevated LFT.
Immune tolerant phase
105
a pt with pulsatile vessels w/oin the IC spaces and diminshed femoral pulses relative to brachal pulses is assoicated with what condition?
turner syndrome (aortic coarctation, note they can have bicuspid aortic valve also)
106
to inactivate thrombin heparin must bind to both antithrombin and thrombin together to form a ternary complex to inactivate thrombin. can unfractionated heparin or low molecular weight heparin do this?
only Unfractionated heparin has a pentasaccharide chain olong enough to do it. Vs LMWH that has greater activity against factor Xa than thrombin.
107
main virulence factor in a pt with salmonellaosteomylitis. (gives you a 24 yo black pt with hx of pain crisis. They are now complaining of thigh pain. You must conclude its Sickle cell
capsule "vi anten that protects it from opsonization and phagocytosis.
108
whats the main virulence factor of Staph aureus in osteomyelitis?
adhesion to collagen
109
whats the main virulence factor in a pt with pseudomonas causing osteomyeliti? particulary in _____ pts
blue green pyocyanin pigment and this is common particulary in IV drug users
110
what groin hernias occur BELOW the inguinal ligament
femoral hernias!!! Its also lateral to pubic tubercle and lacunar ligament (Immediately lateral would be femoral vein) ABOVE = direct and indirect
111
what are femoral hernia prone to? Due to the femoral canal being small.
Incarceration which (cannot be reduced) this can cause bowel obstruction. This can lead to strangulation (few hours after incarceration due to impaired blood flow.
112
granules containing cells containing eosinophils and the crystaloid bodies are most likely?
charcot-leyen crystals (contain eosinophil membrane proteins) can see in extrinsic allergic asthma
113
if a parkinson pt is given IV dopamine and it does not work. What structure accounts for this?
tight junctions (the BBB is made from Tight junctions (zonulae occludentes) are composed of transmembrane proteins (claudins and occludins)
114
PaCO2 is major stimulator of respiration in healthy individuals, however in patients with chronic COPD have dec sensitivity to PaCO2. these pts also have hypoxemia (pao2\< 60) so arterial PaO2 levels become a significant contributor to the respiratory drive.. when supplemental oxygen is administered the rapid increase in PaO2 can reduce peripheral chemoreceptors stimulation dec in respiratory rate. thus this pts reduced spiratory rate is most likely caused by a sudden dec in stimulation of WOTF sensory receptors
peripheral chemoreceptors found in the carotid bodies and aortic bodies are the primary sites for sensing arterial Pao2 and are stimulated by hypoxemia.
115
anterior compartment syndrome of lower leg with affect what structures?
deep peroneal nerve, anterior tibial artery, foot extensor muslces. Deep peroneal nerve injury (dec sensation to 1st-2nd toes, dec dorsifelxion of the foot, foot drop, and claw foot)
116
pt that has sex with men, has symptoms of serum sickness like syndrome with joint pain, lymphadenopathy, and a pruritic Urticarial vasculitis rash, no jaundice and liver slightly enlarged. What infect does this pt have
acute hepatitis B , with symptoms including systemic skin and joint symptoms; hepatomegaly and elevated transaminases levels.
117
enterococcal endocarditis (diastolic murmur at the left sternal border, nontender erythematous macules on hands and feet,fever no hx of heart disease): gamma -hemolytic (no hemolysis on agar), catalase-negative, pyrrolidonyl arylamidase +, lancefield group D gram + cocci that can greow in hypertonic (6.5%) saline and bile. (represents up to 30# of nosocomial endocarditis cases) what is the most likely procedure this patient had done w/in a month to get this.
the genitourinary tract (cystoscopy) is the most common portal of enry; gi (colonscopy) or obstetric procedures are also risk factors.
118
(UPP) ubiquitin proteasome pathway is essential for breakdown of intracellular proteins, both native and foreign, helps recycle AA building blocks. Ubiquitin functions as a tag that is attached to proteins to mark them for destructions. This process is performed by what enzyme?
Ubiquitin ligases, which recognizes specific protein substrates and catalyze ubiquitin attachment. Tag protein --\> proteasome (which breaks it down into their constituent oligopeptides --\> AA
119
so UPP role in immune response is related to its ability to degrade foreign intracellular proteins (viral). These proteins are degrades, and couple to?
major histocompatibility class I protein complexin the ER. They are then expressed on the cell surface for resentation of cytotoxic CD8+ lymphocytes.
120
what organism. Oxidase +, gram -, comma shaped able to grow on high alkaline selective media (thiosulfate-citrate-bile salt-sucrose agar). This organism causes small outbreaks of water-borne gastroenteritis. What would be seen on stool microscopy in terms of leukocytes, etc.?
Vibrio cholerae - mucus and some sloughed epithelial cells. Since this is WATERY diarrhea, noninflammatory(enterotoxin) no fecal leukocytes or Red cells (erythrocytes)
121
triad: cerebellar ataxia (gait is unsteady, spontaneously falls, eyes and head do not move smoothly) telangiectasias "spider angiomas (superficial blanching nests of distended capillaries sun exposed areas) inc risk of sinopulmonary infections. What is the cause of this disease
ataxia telangiectasia - caused by defect in a gene that codes for the ATM gene which is responsible for DNA break repair. The immune def primary manifests as an IgA def and predisposes to infections inn upper and lower airways.
122
what lymph node drains the scrotum (pt with a scrotal abscess might have inflammed _____ nodes)
superficial inguinal lymph nodes
123
what lymph nodes receive lymph drainage from the glans penis and supericial nodes
deep inguinal nodes
124
if you have a left temporal hemiretina. Transmission of visual info to what structure disrupted?
left lateral geniculate body
125
if you have 20 obervations record bw 10-12. if the next measurement is 26 what most likely to remain unchanged? Mean , mode, median, or standard deviation
mode- bc it’s the most frequently observed data point. Vs mean which is the average.
126
they describe an HPV infection of the labia majora with warts. The virus also has affinity to infect what other structures?
true vocal cords not false, cervix, anal canal, vagina, HPV has a predilection for stratified squamous epithelium. In the repsiratory tract the true vocal cords are the only structure with squamous.
127
the internal polypeptide assembly of HDV is (HDAg). Hep B assist what life cycle aspect of HEP D to cause infection?
coating of viral particles: HDAg is considered replication defective as it must be coated by the external coat hep B surface antigen (HBsAG) to penetrate the hepatocyte.
128
18 you with intermittent burning sensation in his palms and soles that is exacerbated by stress and fatigue, he also has cluster of nonblanching red papulels in gluteal inguinal and umbilical areas. Labs: undectable a-galactosidase A. what is this pt at greatest risk of developing
renal failure. (pt has FABRYS disease)
129
turners syndrome: most likely underlying mechanism for this condition?
Meiotic nondisjunction during gametogenesis (aneuploidy mc due to meiotic nondisjunction)
130
a pt that is experiencing an acute hemolytic transfusion rxn. (fever and chills, chest and or back pain, and hemoglobinuria (red-to brown colored urine), hypotension, dyspnea). Whats the cause?
complement - mediated cell lysis (type II hypersensitivity)
131
the most common organ injured during blut trauma ?
spleen.
132
this organ is supplied mainly by an artery of the forgut even though the organ itself is not a foregut derivative. (look at a CT/mri of the abdomen and choose the correct organ.
spleen (derived from mesoderm) its not foregut. Like liver, gallbladder and pancreas.
133
a pt with impaired nutrient absorption (malabsorption) the pt is presenting with either loose stools or steatorrhea. The most sensitive strategy for screening for malabsorptive disorders is?
stool microscopy with sudan III stain): identifies unabsorbed fat and confirm malabsorption. Fats are the Earliest and most severely affect nutrient in generalized malabsorption and test for fat malabsorption is most sensitive.
134
the great saphenous vein is used for LAD revascularization. Know where its located!
courses superiorly from the medial foot, ant to the medial malleolus, and up the media laspect of the leg and thigh, in the proximal anterior thigh, 3-4 cm inferolateral to pubic tubercle, dives deep through the cribiform fascia of the saphenous opening to join femoral V. surgeons access it usually in medial leg, or less commonly in the \*femoral triangle (inguinal lig superiorly, sartorius muscle lat, adductor longus m. medially.
135
flue-like febrile illness w/ marked myalgias and joint pains (break bone fever) retro orbital pain, rash (white islands in sea of red)
classic dengue fever ( vs. dengue hemorrhagic fever: inc vascular perm, thrombocytopenia (\<100,000), spontaneous bleeding --\> shock), + tourniquet test
136
a homeobox is a high conserved DNA sequence of about 180 nucleotides. A gene containing this sequence is called a homeobox or hox gene which codes for?
transcription factors
137
which tissue cant utilize ketones for energy? Erythrocytes, heart muscle, renal cortex, skeletal muscle, brain?
erythrocytes (no mitochondria) ketone bodies are generated in liver, from FA and yields energy when converted to acetyl coa in mitochondria.
138
the presense of hemosidern-laden macrophages in pulmonary alveoli indicate chronic elevation of pulmonary capillary hydrostatic pressure, most commonly as a result of?
left sided heart failure
139
23 yo admitted for herpes encephalopothy (HA, fever, confusion) cerebrospinal fluid shows lymphocytic pleocytosis. The pt is treated with intravenous high dose acyclovir. He improves greatly. But 3rd day in hospital pt serum creatininne lv inc 3.4 from 0.9 how could this have been prevented?
aggressive intravenous hydration: intravenous acyclovir --\> crystalline nephropathy crystals --\> tubular damage. due to acyclovir exceeding its solubitility and now causes
140
what would you expect to see interms of carboxyhemoglobin (%) [norm =0-2], PaO2 [norm= 85-100], and methemoglobin (%) [norm 0-1] if pt is suffering from CO poisoning
carboxyhemoglobin (40), PaO2 (95), methemoglobin (1). CO binds to hb with much higher aff than o2. hereby preventing oxygen binding to hemoglobin. It reduces oxygen unloading from hb, in the tissues. Co poisoning inc carboxyhemoglobin [] but does not affect the partial pressure of oxygen and does not precipitate methemoglobinemia.
141
Bean-shaped gram negative coccci in pairs. Second most common cause of meningitis in pts \< 60
Neisseria meningitidis
142
blood oxygen saturation in fetus is highest where?
inferior vena cava
143
45 yo, shows a CT of brain with mass in the parasagittal region and progressive neurologic symptoms, headache, whats the most likely cause
meningiomas (common, slow growing (Benign) intracranial tumor, arise in regions of dural reflexction (falx cerebri, tentorium cerebelli)
144
is a meningioma is compressing the right .parietal lobe, located behind central sulcus, particuraly compressing the postcentral gyrus. What does this contain "sensory or motor", You would expect the patient to have what symptoms?
it contains the somatosensory cortex - thus a medial location of a tumor would result in contralateral sensory loss in the lower limb. Also if it involved the parietal association cortex on the right (nondominant hemisphere) you would see contralateral. hemineglect. due to this regions role in visuospatial processing
145
fever, back or flank pain, inguinal mass, and difficulty walking. Pt prefers to keep his leg flexed and exsternal rotation. What muscle is affected?
psoas abscess (major function flexion of hip) pain exacerbated when muscle stretched or extended. (extension of the hip = psoas sign)
146
condensed body composed of heavily methylated DNA at the periphery of the nucleus. This region of DNA is most likely associated with what genetic finding?
low transcription activity (example compact herterchromatin (Barr body)) herterochromatin is condensed chromatin composed of heavily methylated DNA in Tight associated with Deacetylated histone. Thus it has low levdel of transcriptional activity. contrast - euchromatin (loosly arranged and exhibits a high level of transcriptional activity
147
systemic arterial pressure normally falls by \< 10mmhg during normal inspiration. What is it called when it drops (\> 10 mmHg)
pulsus paradoxus: its detected by inflatting a BP cuff above systolic pressure and gradually deflating it. The diff bw the systolic pressure at which korotkoff sounds first become audible during expiration and the pressure at which they are heard throughout all phases of respiration quantifies pulsus paradoxus
148
bp cuff is inflated to 140 and pressure release. At 120 intermittent korotkoff sounds are heard only during expiration. At 100 mmhg, korotkoff sounds are heard throughout the respiratory cycle. This PE finding can be seen in which of the following conditions\>
pericardial disease
149
pathology of how pericardial disease (acute cardiac tamponade) can impair expansion.
the inc right Vent volume occuring with inspiration ---\> bowing of the interventricular septum toward the left vent. This leads to a dec in LV EDV and SV. With a resultant dec in systolic pressure during inspiration
150
increased activity of a specific intracellular enzymes are more susceptible to developing benzopyrene-induced lung cancer. What over active enzyme is the cause?
microsomal monooxygenase (cytochrome p450 monooxygenase) most chemical carcinogens enter body in inactive state (pro-carcinogens). They are converted to active metabolites by CYP 450 oxidase system
151
both multiple motor & \> or = vocal tics (grunts, snorts, throat clearing, sniffling, coprolalia) (not necessarily concurrent, \> 1 year) onset before age 18 diagnosis and tx?
tourette disorder and TX: antipsychotic, alpha-2 adrenergic receptor agonists, behavioral therapy.
152
if shown a picture of langerhan giant cells (multiple nuclei peripherally organised in shape of horseshoe) in a pt with TB. What is the most like cause of this finding?
stimulation by CD4+ Th1 lymphocytes (the macrophages that form these giant cells are activated by CD4+ TH1 lymphocytes) langhan giant cells are characteristic of granulomatous conditions.
153
topical prostaglandins (latanoprost) help tx glaucoma how?
inc outflow of aqueous vis the uveoscleral pathway and are preferred tx for open-angle glaucoma.
154
histo shows diffuse infiltrate of lymphoid cells w/ numerous mitotic figures, and interspersed macrophages surround by clear spaces. This is describing?
burkitts lymphoma: benign macrophages that pahgocytize the resulting cellular debris ("tingible body macropahges") are diffusely distributed throughout the malignant tissue. The clear spaces that surround these macropahges contribute to the starry sky appearance.
155
in burkitts lymphoma the gene translocated in these lymphoid cells produces a protein that is most directly responsible for?
transcription activation. C-Myc oncogene on long arm chromosome 8 and Ig heavy chaing region on chromo14 [t(8:14)] the product of c-Myc is a nuclear phosphoprotein that functions as a transcription activator controlling cell proliferation, differentiation and apoptosis.
156
in follicular lymphoma T 14:18. this leads to overexpression of the BCL-2 that functions to
apoptosis inhibitor protein
157
G protein coupled receptors that bind glycoprotein hormones (TSH,LH, FSH) contain 3 major domains: extraceullar domain (ligand binding), a transmembrane doamin, and intracellular domaincoupled w/ heterotrimeric G proteins. The transmembrane domain is made up of nonpolar, hydrophobic amino acids (alanine, valine, isoleucine, phenylalanine, tryptophan, methionine, proline, glycine). they are arranged in an alpha helical fashiion (7-alpha helices) and project their hydrophobic R groups outwardly which functions to?
anchoring the transmembrane region of the protein to the hydrophobic core of the phospholipid bilayer. Answer choice (anchoring to the cell membrane)
158
cancer cells may develop the ability to alter the FAS proteins and fas receptors by converting it to a soluble form that is not expressed on the cell surface, which allows it to evade apoptosis. How might the cancer cells do this?
alternative splicing: process by which a single gene can code for various unique proteins by selectively including or excluding diff DNA coding regions (Exons) into mature mRNA
159
a pt taking etoposide for testituclar cancer. The teoposide killed cancer cells show a high number of double stranded DNA fractures. These fractures are due to dysfunction of?
topoisomerase II: etoposide is a hemo agent that inhibits the sealing activity of topoisomerase II. Tx w/ etoposide causes chromosomal breaks to accumulate in dividing cells --\>. Cell death.
160
irinotecan/topotecan inhibit eukaryotic \_\_\_\_\_\_? Leading to accumulation of Single stranded DNA breaks.
topoisomerase I
161
what bacteria is associated with toxins that bind specific receptors on intestinal mucosal cells and are internalized allowing both toxins to inactivate Rho-regulatory proteins involved in signal transduction and actin CYTOSKELETAL STRUCTURE\*\* maintenance. as a result the toxin cuases diruption of intracellular TIGHT junctions --\> cell rounding/ retractio0n and increased (paracellular) intestinal fluid secretion.
C difficlile: Toxin A (enterotoxin) and Toxin B (cytotoxin)
162
what are the most important opsonins (coating proteins)?
IgG (immunoglobulin) and complement C3b
163
neuropathologic findings in pts with friedeich ataxia are due to?
spinocerebellar and lateral corticospinal tract degeneration (gait ataxia and spastic muscle weakness), other characteristics of the disease 2. degeneration of dorsal colums and dorsal root ganglia (loss of position and vibration sensation). 3. kyphoscoliosis and foot abnormalities (pes cavus), 4. hypertrophic cardiomyopathy annd CHF, 5. diabetes mellitus develops in 10% of pts.
164
pt recently returned from Mexico, presents w/ low grade fever, anorexia/nausea, dark colored urine, and right upper quad abd tenderness for two days is highly suggestive of? What findings are most likely to be seen in liver biopsy?
acute HAV, acute hepatitis due to most hepatropic viruses causes hepatocyte swelling: hepatocyte ballooning degeration and apoptosis w/ mononuclear cell infiltration. (hepatocyte necrosis is characterized by cellular swelling and cytoplasmic emptying (ballooning degneration) likely caused by ATP depletion and diruption of intermediate filament network.)
165
why might blood glucose be normal and not fall into hypoglycemic range w/ fasting. Which hormone contributes to this pts labs by binding to an intracellular receptor?
by counterregulatory hormones specifically in this patient cortisol: unlike the other counterregulatory hormone receptors, cortisol receptors are located w/in cytoplasm and translocate to the nucleus after binding to their substrate. In the nucleus. The cortisol receptor complex binds to hormone responsive DNA elements, altering gene transcription to enhance hepatic glucose production and limit peripheral glucose utilization.
166
pt with crampy abdominal pain and vomiting. Previous hx of acute calculous cholecystitis. PE: distended typanic abdomen w/ high pitched bowel sounds. Abd xray: air in gallbladder and biliary tree. Diagnosis and this pts gallstone is most likely lodged in what site?
Gallstone ileus common complication of longstanding choleithiasis. Usually occur elderly women. A large (\>2.5cm) gallstone causes formation of cholecystoenteric fistula bw gallbladder and adjoining gut (most often duodenum) due to pressure necrosis and erosion. fistula allows gall stone into small bowel where it becomes trapped in ileum. --\> small bowel obstruction.
167
pt in bat cave 4 wks later develops painful spasms, progressive paralysis, coma, dies. What intervention would most likely prevented the development of this illness?
\*inactivated vaccine = prophylactic vaccination, post exposure: vaccine and rabies immune globulin immediately after exposure to high risk wild animal.
168
whats the long term effects of estrogen tx on thyroid hormones
increased total T4 pool NOT (dec free T4 levels).circulating thyroid hormone consist of 2 fractions, a protein bound fraction (not active) and free fraction that’s able to enter target cells via carrier mediated mech. more than 99% of circuating thyroid hormone is boundn to plasma protein creating a large circlating reservoir pool of thyroid hormone. Inc estrogen activity --\> inc circulating TBG levels which causes reduction in Free T4 and T3. this causes a transient inc in thyroid hormone production until the additional TBG becomes saturated w/ thyroid hormone, and free t4 and t3 are restored. thus inc TBG --\> inc in total t4 (bound T4 + free T4) as well as total T3. however the level of free thyroid hormone remaind normal.
169
hallucinations of recently deceased relatives in children are part of a normal grief rxn and may not be indicative of major psychiatric illness. True or false?
true.
170
what is kinesin protein function?
microtubule associated motor protein: function is ANTEROGRADE transport of intracellular vesicles and organelles toward the plus (rapidly growing) ends of microtubuels
171
toxic insult to protein kinesin. Which of the following is likely to be absent from tissues on histological examination as a result?
secretory vesicles in nerve terminals.
172
a pt with multiple myeloma. You expect to see what lab values for urinary ca, pth, PTH related protein, 1,250 dihydryoxyvitamin D.
pth dec, urinary ca inc, 1,25 vit D = dec, PTH related protein normal. (hypercalcemia due to osteolysis induced by tumor cells. Inc serum Ca inhibits PTH production, low levels of PTH caused inc Urinary loss of CA (hypercalciuria). Hypercalcemia and light chain cast nephropathy --\> progressive renal failure --\> low 1,25 vit d
173
what part of the TCA cycle is dependent on thiamine
a - ketoglutarate --\> succinyl coa. Need it for A ketoglutarate dehydrogenase complex.
174
in pt with delta F508 mutation cystic fibrosis transmembrane conductance regulator (CFTR). Wotf electrolyte disturbances is most likely due to the 1month symptoms of (lethargy, vomiting) and dehydration from vomiting?
hyponatremia bc the CFTR protein is regulating the CL channel that allows NA, CL, water flow across the pithelial membranes of the airways, biliary tree, ,intestine, and sweat ducts, and pancreatic duct. Postiive sweat test with have high CL and NA in it. tx is salt supplementation
175
immigrant withhx of cardiac rhythm abnormalities and presents with well demarcated erythematous rash on face and trunk. Pt denies hair loss, mucosal ulceration, or photosensitivity.. Has a + ANA. The pt should be specifically question about the intake of what med?
procainamide = drug induced lupus (Hydralazine, procainamide, isoniazid, minocycline, quinidine)
176
autosomal recessive polycystic kidney disease (bilaterally enlarged kidneys will diffuse small cyst in fetal kidneys and oligohydramnios). What is most likely to be present in newbord after birth?
respiratory distress
177
what will you see on liver biospy in child with reye syndrome?
microvesicular steatosis
178
30 yo ASIAN male w/ extertional calf pain and painful foot ulcers demonstrates Hypersensitivity to intradermally injected tobaco extract. What pathologic processes is most likely responsible for this pts condition?
segmental vasculitis extending into contiguous veins and nerves. Pt has thromboangiitis obliterans (buergers disease),usually seen in smokers, w/ onset before age 35, associated w/ hypersensititivity interdermal injections of tobacco extracts. This segmental thrombosing vasculitis often extends into contiguous veins and nerves, encasing them in fibrous tissue
179
clostridium perfringens, can cause gas gangrene, what else is it commonly associated with?
transient watery diarrhea and abd discomfort.
180
a pt with parkinsons. Genetic analysis shows Loss of function mutation in a gene that leads to an accumulation of misfolded proteins. What biochemic process is most likely defective in this pt?
ubiquitination: ubiquitin is a protein that undergoes ATP-dependent attachment to other proteins, labeling them for degradation. These modified proteins enter the proteasome and are degraded into small peptides. Impairtment of the ubiquitin-proteasome system --\> development of neurodegenerative disorders. (parkinsons, and alzheimers)
181
what is the underlying mechanism for a zenker diverticulum formation?
cricopharyngeal motor dysfunction: abnormal spasm or diminshed relaxation of the cricopharyngeal muscles during swallowing.
182
old man with HF. Displaced apical impulse at 6th ic space, S3 high volume, collapsing carotid pulses. Bilat pedal edema, mild heptomegaly. Dec light touch and vibration In feet, w/ dec knee and ankle reflexes bilat. Generalized weakness, fatigue, tingling both lower limbs. what nutrient def?
thiamine : wet beri beri : high output congestive heart failure + dry beri beri symptoms of symmetrical peripheral neuropathy)
183
26 yo found dead. Long hx of alcohol and drug abuse and did rehabilitation 6 months ago. Pt had a hx of depression and anxiety that was being treated. According to epidemiological data, overdose of WOTF drug grps is most likely related to her death? (A. alcohol, B. Benzos, C. Opioids)
opioids. In the US the majority of overdose deaths ar ecaused by opioids (analgesics and heroin)
184
pt with reperfusion injury due to ROS. Which enzyme / enzymes will are most likely to neutralize these toxic molecules?
glutathione peroxidase, SUPEROXIDE dismutase, catalase. (all convert ROS- --\> h2o and oxygen.
185
polygenic inheritance means it depends not only on genetics. Example?
androgenetic alopecia (male pattern baldness) = mc type of hair loss in male and females. Driven by both hormonal and genetic factors.
186
cancer above the pectinate line in rectum what lymph nodes should you check
internal iliac
187
multinucleated giant cells can indicate what infection that has vesicles
herpes infectiono such as shingles.
188
what is effect modification? (its most common confused with confounding bias)
effect mod: is present when the effect of the main exposure on the outcome is modified by the presence of another variable. It will show significant difference bw the strata, vs confounding bias usually does.
189
19 yo brought to ER for MVA accident, hx of celiac disease and 3 episodes of pneumonia. BP 80/45, pulse 130, US: splenic laceration. She is transfused with O negative packed RBCs. During transfusion the pt develops facial swelling, generalized hives and SOB. Diagnosis?
Selective IgA def: presents: usually asymp, recurrent sinopulmonary ,GI infections, autoimmune, ANAPHYLAXIS during transfusions. Diagnosis: low or absent serum IgA levels, normal IgG and IgM
190
def in ornithine transport from cytosol into mitocondria. 4 yo presents with poor feeding and vomiting, exacggerated deep tendon reflexes. What nutritional restriction can help improve this pts condition
limit proteins. Def in ornithine translocase def, which results in defect in hepatic urea cycle. Which converts ammonia generated from AA catabolsium into urea, urea cycle defects ause ammonia to accumulate in blood --\> progressive lethargy, vomiting, seizures, cerebral edema (hyperreflexia, chorea, abnormal posturing if severe)
191
collagens triple helical conformation occurs due to the simple and reptitive AA squence w/in each alpha chain. Which AA is most likely to be found in highest quantitiy in these fibrillar proteins (fibrils separated)? A. proline B. glycine, C. lysine
glycine: occupies every third amino acid position (Gly-X-Y)
192
quartback take blow to arm when throwing, flattening of the deltoid. Loss of sensory to deltoid What is the injury
anterior dislocation. Classically follow blow to an ext Rot and abd arm (throwing a football). When head of huemrus is displaced ant, there is flattening of deltoid prominence, protrusion of acromion, and ant axillary fullness.
193
what nerve is must commonly injured during anterior dislocation of humerus. What does it innervate
axillary n. sensory innervation to deltoid and teres minor.
194
DRESS syndrome can be caused by drug rxn to anticonvulsants (\*\*phenytoin, carbamazepine), allopurinol, sulfonamides, and abx (minocycline, vancomycin). Pt present with fever, generalized lymphadenopathy, facial edma, and diffuse morbilliform skin rash that can progress to confluent erythemia with follicular accentuation. what will be elevated on labs?
eosinophilia! Can also affect liver (hepatomegaly, jaundice), kidney (Acute intersitital nephritis) and lung (cough dyspnea)
195
administration of a drug can causes coronary steel syndrome = redistribution of blood flow away from ischemic areas, exacerbating existing MI. A drug that cause __________ effects is most likely to be associated with this phenomenon?
coronary arteriolar dilation (not systemic arterial dilation.)
196
the most important limiting factor for left ventricular blood supply during a stress test is?
duration of diastole (that’s when ventricles fill)
197
decreased numbers of functional T-Tubules in affected muscle fibers leads to?
uncoordinated contraction of myofibrils. This manifest as muscle weakness (limb girdle muscular dystrophy most likely in this question stem due to mutated sarcolemma protein (caveolin) affecting excitation contraction coupling). T-tubules allow for depolarization impulse to rapidly propagate through the interior muscle fiber. this ensures that calcium release from the sarcoplasmic reticulum occurs uniformly throught the fiber. allowing synchronized contraction.
198
primary aldosteronism can present how?
muscle weakness and paresthesias (due to hypokalemic alkalosis), also HTN
199
what Molecule is most likely involved in mediating te accumulation of pus?
IL-8. is a chemokine produces by macrophages, that induces chemotaxis phagocytosis in neutrophils. Other significant chemotactic agents includes: N-formylated peptides, leukotriene B4, 5-HETE (the leukotriene precursor), and component C5a. Trick - not Leukotriene C4.
200
70 man. Presents for 3 weeks unrelenting low back pain. No trauma but describes having to strain to urinate. Has not seen a dr in 5 years. Tenderness in lower vertebral area. Imaging of spine shows osteoblastic lesions in lumbar vertebrae. WOTF is most likely part of the spread of this pts disease
prostatic venous plexus (not internal iliac lymph nodes.
201
accentuated pulmonary component of the second heart sound and signs of right sided heart failure due to cor pulmonale. These manifestations represent?
pulmonary arteriole hypertension, can develop in pts with system sclerosis as a result of damage to the pulmonary arterioles (this pt had sclerodactyly) the cause of the pts presentation was \*\*\*\* intimal thickening of pulmonary arterioles.
202
the MMR vacine for Rubella is what type of vaccine
live attenuated.
203
during cardiac cath, puncture of the common femoral artery above the inguinal ligament increases the risk of ?
retroperitoneal hemorrhage, as this portion of the vessel lies directly inferior to the peritoneum. Note: retroperitoneal bleed cannot be controlled with external compression and --\>. Lead to life threatening hemorrhage.
204
a pt with retroperitoneal hemorrhage generally present with
significant hypotension, drop in hemoglobin, ipsilateral flank painl
205
right paracolic gutter is a peritoneal recess found bw ascending colon and abd wall.
fluid bile pus blood typically accumulates here with GI organ pathology. (appendix, gallbladder)
206
Interleukin-2 produced by T helper cells whats its function of IL-2
stimulates growth of CD4+ and CD8+ T cells and B cells (stimulation of division), activates NK cells and monocytes, the inc activity of T cells and NK cells is thought to be responsbile for IL-2 anti-cancer effect on metastic melanoma and RCC.
207
what is the mechanism for stress urinary incontinence during pregnancy
increased intraabdominal pressure (from the gravid uterus that exceeds the pressure point that maintains closure of the urethral valve)
208
zinc finger motifs ( around 30-35 AA bound around a zinc atom via linkage w/ cysteine and histidine residues. A receptor for WOTF hormones was most likely isolated?
thyroid hormone, also intracellular receptors that bind steriods, and fat soluble vits act directly as transcription factors and contain the zinc finger binding domains
209
PPIs can inc or dec risk of osteoporotic fractures with longterm use?
inc risk. Bc strong acid suppressing meds may dec absorption of dietary calcium in GI tract..
210
8 yo boy with fever, throat pain, severe dyspnea, tachypneae, inspiratory stridor, also worsening dysphagia w/ solid foods over pasted two weeks. On peripheral blood smear (blasts) immature hematopoietic cells. The neoplastic cells causing this condition normally given rise to what?
t-lymphocytes not B-lymphocytes. T-cell ALL often presents as a mediastinal mass that can cause respiratory symptoms, dysphagia (compression of esophagus from mass), or superior Vena cava syndrome. Not B cell ALL is most common cause of ALL. Other symptoms of ALL (fever, fatigue, pallor, petechiae, bleeding. if spread it can cause lymphadenopathy, hepatosplenomegaly and bone pain.
211
what changes in bone structure do you expect in pt with primary hyperPTH
subperiosteal resorption (subperiosteal erosions in phalanges on hand, with cystic degeneration (osteitis fibrosa cystica), and granular salt and pepper skull
212
contact drematitis, granulomatous inflammation, tuberculin skin test and the candida extract skin rxn (inject it under skin then see nodule). The response observed for all of theses is caused by what cell type?
T- lymphocytes (TH1) these are all examples of delayed type hypersensitivity reaction (DTH) . DTH are TH1 lymphocytes that release .interferon gamma to cause recruitment and stimulation of macropahges.
213
regardless if your patient has a duodenal peptic ulcer or gastric ulcer. Biopsy at which site would show the infectious agent (H. pylori)?
gastric antrum!
214
3 yo girl w/ several months of fatigue and difficuly walking. She ambulates normally at first but rapidly becomes weak and tired. Hx of mild motor delays, but otherwise developmentally normal. Normal vitals. Mild decreased power in all 4 extremities but no ataxia. 1/6 systolic murmur and S3 gallop. she is hypotensive and creatine kinase (304). muscle biopsy shows very low carnitiine content. which substance has deficient synthesis?
acetoacetate. (primary carnitine def) Carnitine def impairs FA transport from cytoplasm into mitochondria, preventing B-oxidation of FA into acetyl coa. This leads to cardiac and skeletal myocyte injury (lack of ATP from citric acid cycle) and impaired ketone body (acetoacetate) production by the liver during fasting periods (this is also seen in other FA oxidation disorders (medium- or very long chain acyl coa dehydrogenase def)
215
4 yo white boy, difficulty walking. Hx of frequent respiratory infecitons. Cultured cells show high rate of radiation-induced genetic mutations. This pt is most likely experiencing?
cerebellar atrophy. This pt has Ataxia telangiectasia. Def in ATM gene --\> failure to repair DNA double strand breaks --\> cell cycle arrest. Triad: cerebellar defects (ataxia), spider angiomas (telangiectasia), IgA deficiency.
216
in the retroperitoneum, the ureters pass posterior to the? And anterior to the? To reach the true pelvis
ureters pass posterior to the ovarian (gonadal) vessels. ANTERIOR to the common/external iliac arteries
217
w/in the true pelvis the ureters lie Anterior to the _____ arteries. Medial to the \_\_\_\_\_\_?
ureters lie anterior to the \* internal iliac artery and medial to the ovarian vessels. The uterine artery crosses over the ant surface of the ureter
218
pt is being treated with polyethylene glycol or magnesiumcitrate ("osmotic laxatives). The moa in this pt is most similar to the pathophys of what GI disorder?
lactase def (its causes osmotic diarrhea)
219
56 yo. Admitted w/ dehyrdration secondary to excess otuput from ileostomy. Pt had total colectomy. For the last 6 months, hes had inc output from the ileostomy and has been admited twice w/ similar episodes of dehydration. On the 2nd admin, he has r. flank pain, ,no renal calculi on xray, US of abdomen shows 4 mm stone in distal right ureter. what is the underlying mechanism leading to stone formation in this pt.
increased hydrogen ion excretion in kidney (not inc uric acid production). Pt has Recurrent epidosdes of dehydration due to ileostomy, patients with chronic diarrhea or those who have colectomy have reduced bicarb reabsorption from gut, --\> state of chronic metabolic acidosis. the kidney compensate by increasing the excretion of hydrogen ions and reabsorption of bicarbonate in the collecting ducts. inc uric acid production would be caused moree from high cell turnover (malignancies, lymphoproliferative disorder) or inborn errors of metabolism (glucose-6- phosphate def)
220
parents tell 14 yo they are getting a divorse. He now is unusually quit. He hardly speaks. The child avoids his parents bc he feels that they are angry with him. He acknowledges that they have not expressed anger toward him, but he "can sense it" what defense mechanism is this
projection (attributing ones own feeling to others)
221
know what the left ventricular pressure volume loop looks like for Arteriovenous shunt
av shunt result from the formation of AV fistulas. it will dec TPR, (inc preload, dec afterload).
222
women at 38 week uncomplicated pregnancy, has .gallstones. No abnormalities on US 1 year ago. What pathogenetic components is most likely contributed to this pts condition?
estrogen induced cholesterol hypersecreteion and progesterone induced gallbaldder HYPOmotility. Pregnancy and the usage of OCP predispose to gallstone formation. estrgoen inc cholesterol synthesis by upregulating hepatic HMG-CoA reductase actiivty, causing bile to be supersaturated w/ chcolesterol. progesterone dec bile acid secretion and slows gallbaldder empyting. (incorrect - estrogen induced bilirubin hypersecretion and cortisol mediiated cholesterol hypersecretion.
223
study shows sudden inc in postopt infections in hospital, in pts operated on w/ surgic instruments sterilized by broken autoclave machine that only reached tep of 212. what bacteria is responsible?
clostridium perfringens ( spore forming bacteria, sporse can survive past boiling point)
224
pt develops drug induced lupus (+ anti histone ab), hemglobin 12.5, platelets 120,000, leukocytes 11000. abnormality in what metabolic processes most likely underlies this pts current condition
liver acetylation. Drug induced lupus has been linked to drugs metabolized by N aceylation in the liver (procainamide, hydralazine, isoniazid). Genetically predisposed individuals who are slow acetylators are at greater risk
225
most common pathogens causing nosocomial bloodstream infections?
Coagulase-negative staphylococci, staphylococcus aureus, enterococci, candida species. Question said study saw inc in staph BS infection is most likely related to inc use of? Intravascular devices (not surgical antiobiotic prophylasis)
226
what is the most frequent mechanism of sudden cardiac death in the first 48 hours after acute MI,
Ventricular fibrillation (related to electrical instabillity in the ischemic myocardium)
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infant born to 26 yo mom, birthwt/length 10/15th%, protruding tongue, excessive skin at the nape of the neck, upslanting palpebral fissures. Startle reflex is weak. Harsh, III/IV systolic murmur over left sternal boarder (VSD). mom has had miscarrages what karyotyping would you see?
DOWNS syndrome most commonly causes by random meiotic nondisunction (47,XX,+21), answer was unbalanced roberstonian translocation with 46 chromosomes and 3 effective copies of chromo 21 \*\*[46,XX, t(14;21)]
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60yo Er with Diplopia started hours ago. Long standing diabetes w/ pour glycemic control. PE: Right sided ptosis w/ R pupil in the inferolateral position (now u know its CN3), pupils are = size and reactive to light bilaterally (thus you know psns is still working bc no dilation in one eye). this condition is most likely due to?
Nerve ischemia. (diabetic CNIII mononeuropathy) WHY? Bc if it was due to nerve compression you would have parasympathetics injured first (dilated pupil "blown") since it wraps the nerve. Classic presentation in diabetics w/ acute onset diplopia, and "down and out" position. also Ptosis occurs due to paralysis of levator palpebrae.
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why would you give someone with St seg elevations in the inferior leads (Inf MI) atropine
inf MI's are often due to RCA blockage, the artery usually responsible for SA and AV node perfusion. Thus INF MI are often associated w/ bradycardia. ATROPINE blocks vagal influence on the SA and AV nodes and is effective in increasing HR.
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Gastric bypass surgery can cause small intestinal bacterial overgrowth(SIBO) due to excessive bacterial proliferation in blind-ended Gastroduodenal segment. SIBO results in a def in? and a Inc production of?
def: most vitamins (B12, A,D, E) and IRON, But an increase production of FOLIC ACID and Vit K
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cleft lip results from failure of what intrauterine process?
fusion of the maxillary prominence and intermaxillary segment (not fusion of the 2 medial nasal prominences (which forms the intermaxillary segment) this is associated with severe midline defect like holoprosencephaly)
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decribes the lip and palate formation during fifth-sixth week of embryo development,
a series of fusions: 1. the 1st pharyngeal arch splits into upper maxillary prominence and lower mandibular prominence. 2 fusion of the 2 medial nasal prominences forms the midline intermaxillary segment (forms the philtrium of the upper lip, the 4 medial maxiallary teeth, and the primary palate) 3. the left and right maxiallary prominences then fuse with the midline intermaxillary segment to form the upper lip and primary palate. if one of the maxillary prominences fails to fuse with the intermax segment, a unilateral cleft lip occurs.
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spider angiomata are subcutaneous vascular lesions. Whats the pathogensis
occur in hyperestrogenic states (pregnancy, liver failure/cirrhosis) possibly due to estrogens effects on arteriolar dilation. The # of lesions usually correlate to severity of liver disease
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pt with distal duodenal ulcer and high normal gastrin levels that rise in response to secretin administration (should fall) are suggestive of?
zollinger-Ellison syndrome. This condition is caused by gastrin secreting tumors (gastrinomas) often malignant located in small intestine or pancreas. The inc gastring --\> parietal cell hyperplasia--\> inc gastric acid secretion --\> peptic ulcers, heart burn, and diarrhea (excess gastric acid impairs intestinal epithelial cells and digestive enzymes)
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ciliated mucosal epithelium lines from the trachea to the? The terminal bronchioles are covered by?
ciliated mucosal epi (trachea --\> proximal portion of the respiratory brochioles). The terminal bronchioles are coverd by ciliated cuboidal epi, and club cells
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a pt with abnormal sexual differentiation. Karotype analysis shows 46XY genotype, bipsy of gonadal tissue shows a lack of sertoli cells but normally functioning leydig cells. What phenotypes is most likely present for internal reproductive organs and external genitalia
female and male for internal reproductive organs, Male for external genitalia (leydig cells --\> testosterone (wolffian duct to male internal genitalia) --\> DHT (genital tubercle/urogenital sinus --\> Male external genitalia) SRY gene on the Y chromo codes for Testes determining factor --\> allows development of testes. Absent Sertoli cells then no AMH (no mullerian duct involution) thus you get development of internal female reproductive organs (fallopian tubes, uterus, cervix, upper vag)
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pt presents with dyspnea and chronic exertional angina, is evaluated for Coronary revascularization. Echo shows hypokiinesia of ant wall of left vent and LVEF of 35%. After coronary artery bypass grafting. 10 days after echo shows no hypokinesia and LVEF inc to 50%. what best explains the changes in cardiac contractility and wall motion.
hibernating myocardium refers to a state of chronic myocardia ischemia. In which both myocardial metabolism and function are reduced to match a concomitant reduction in coronary blood flow
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guy goes on binge drinking and now presents with glucose of 35mg/dl, urine is strongly positive for ketones. Suppression of what is the primary cause of this pts hypoglycemia
gluconeogenesis. Ethanol is metabolized leading to dec NAD+/ANDH and increases the NADH/NAD ratio. This INHIBITS all other pathways requiring NAD+, such as gluconeogeneiss (lactate cant be converted to pyruvate, and excess NADH inhibits conversion of malate to oxaloacetate.
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pt with a cystic mass (showed a CT) in the Left cerebellum, you would expect what on clincial exam?
left dysdiacdochokinesia (cant do rapid alternating movements)
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pt with hx of substance abuse presents w/ depression, fatigue, hypersomnia, hyperphagia, vivid dreams. What kind of withdraw
Cocaine
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young tall thin male pt with primary spontaneos pneumothroax is most likely caused by?
apical subpleural bleb
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pt had abortion 2 days ago. Present with sudden fever, abd pain, uterine tenderness, foul smelling vaginal discharge. What microbe is responsible.
staph aureus in septic abortion (it is the most common.
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cytokeratins can be used as a marker for what kind of tissue derived tumors
epithelial derived tumors (beast cancer) since its squamous
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Vimentin is an intermediate filament present in what kind of tissue and can be used to detect what type of tumors
Mesenchymal tissue, sarcomas
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Myeloperoxidase is a peroxidase enzyme that can be used as a marker for what type of cells and tumors
myeloid cells, such as those in acute myeloid leukemia
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chromogranin A and synaptophysin are markers used for what tumors
neuroendocrine
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50yo no smoker is found to have a round lesion in RUL of lung. What would favor the diagnosis of Hamartoma?
Hamartoma (pulmonary condroma) = mc benign lung tumor, usually found incidentally as solitary lung nodule (coin lesion). Cartilage tissue in the biopsy sample: lung is most common location and contain islands of mature hyaline cartilage, fat, smooth m and clefts lined by respiratory epithelium
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pt with RA. This PT's serum is most likely to contain IgM antibodies against what substancE?
Fc portion of human IgG = Rheumatoid factor ( IgM antibody specific for Fc component of IgG) RA result from immune response against autoantigens in joints. Infiltrating CD4 T cells secrete cytokines that promote inflammatory synoviits. They also stimulate B cells to produce the RF and anti-citrullinnate protein abs
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pt that’s on chemo presents with fever, chest pain, cough, dyspnea, and hemoptysis, chest xray: consolidation, nodules or cavitary lesions "dense infiltrate in RUL lobe". Bronchoscopy grow mold. Whats the cause?
aspergillus fumigatus
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inc pressure in what vein can be causing bleeding spot within a cluster of enlarged tortuous veins in the gastric fundus
splenic vein. Bc the short gastric veins drain the fundus of the stomach into the splenic vein.
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what is the major virulence factor in H. Influenza type B causing epiglottis
Polyribosylribitol phosphate (is a capsule component and major virulence factor.
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in western nations. A successful hepatocellular carcinoma prevention strategy in these countries would focus on incorporating?
universal vaccination (hep B = 85% of al HCC)
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pt presenting with upper limb pain/weakness, and ipsilateral ptosis and miosis (horners) are highly suggestive of?
pancoast tumor! (which are usually non small cell lung cancers: Squamous cell carcinoma, adenocarcinoma), arise near the superior sulcus. : pt with shoulder pain, upper limb paresthesias, areflexic arm weakness due to brachial plexus involvement
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pt with limb pain weakness in upper limb, shouder pain, ipsilateral ptosis and miosis, smoker, you diagnosis pancoast tumor. This pts lesion is most likely where?
autonomic ganglia ( cervical sympathetic ganglia) bc she has horners syndrome due to this tumor.
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when you inset a chest tube into 5th IC space in midaxillary line. What muscle is dissected during procedure
serratus anterior
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meds associated with osteoporotic fractures
anticonvulsants that induce CYP450 (inc vit D catabolism), Aromatase inhibitors and medroxyprogesterone ( dec estrogen), GnRH agonists (dec testo, estrogen), PPI (dec calcium absorption), Glucocorticoids (dec bone formation) hyperthyroidism ( or over replacemnet of Thyroid hormone (levothyroxine) can lead to osteoporosis)
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thymidine kinase gene mutated in HSV 2 resistant strain is cultured in a cell line and is coinfected w/ a nonresistant HSV 1 strain. Its found that some newly type 1 virions acquire resistant to acyclovir, and subsequent progeny continue to be resistant. what is this called?
recombination (gene exchange that occurs through the crossing over of 2 DS DNA molecules
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mixing of genome segments in segmented viruses that infect the same host cell, (changes in genomic composition that occur when host cells are coinfected w/ 2 segmented viruses that exchange whole genome segments . This is referring to ?
reassortment
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guy with AAA. No syphilis. What pathologic condition is most likely underlying cause?
chronic transmural inflammation ( AAA is associated w/ (\>60, smoking, htn, male, fam hx) --\> oxidative stress, vascular smooth m apoptosis, and chronic transmural inflammation of the aorta. Inflammatory cells (macrophages) release matrix metalloproteinases and elastases that degrade extracellular matrix components (elastin, collagen) --\> weakening and progressive expansion of the aortic wall
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guy w/ malig melanoma. Immunohisto indicates malignant cells have decreased integrin expression. These cells are most likely to exhibit poor adhesion to what component of the extracellular matrix?
fibronectin (also collagen and laminin). Integrins are transmembrane protein receptors that interact with extracellular matrix by binding to specific proteins listed. Note cadherins, selectins, and Ig superfamily members are other adhesion molecules
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what is fibronectin
large glycoproteins produced by fibroblasts and some epithelial cells. Function to bind integrins, matrix collagen, and glycosaminoglycans. Serving as a mediator of cell adhesion and migration.
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what is the main mechanism of excess copper removal in a healthy human body
hepatic excretion into bile
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pt with mild intellectual disability, lymphedema, short stature, webbed neck, and 2 karyotypes (40% of cells have 45,X genotype, and remaining contain 46XX) which of the following is the cause of this pts condition?
somatic mosaicism (mosaic turner syndrome) mosiacism is the presence of multiple, genetically different cell lines within the body. It can result from severe processes, including chromosomal nondisjunction and mutations during the first stage of embryonic development.
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what is somatic mosaicism
affects the cells forming the body, causing disease manifestations to develop in affected individuals. 45,X/46XX is the most commonly diagnossed mosaicism affecting sex chromosomes
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what is germline mosaicism
affects the cells that give rise to gametes, allowing the affected genes to pass to the offspring. Chance of child being affected depends on proportion of gametes that carry the mutation. \* when mosaicism is limited to germline, the affected parent does not develop clinical manifestations.
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a pt is treated for N gonorrhoeae and devlops antibodies against the bacterial pili. His GF isnt treated and now he gets reinfected. Whats the reason for the lack of long lasting immunity against the bacteria despite antibody formation
antigenic variation of the pili
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46 yo man comes to ER for recurrent nose bleeds. Pt has a hx of alcohol abuse and chronic mental illness. He is drunk, PE: swollen gums, scattered ecchymoses, and hyperkeratosis. Has a chronic ulcer on left lower extremity that does not appear to be infected. what is the mechanism for this pts findings ?
clostridium perfringens ( spore forming bacteria, sporse can survive past boiling point)
