Uworld SA 2 Flashcards
Inheritance pattern of Familial hypercholesterolemia?
AD
Defect LDL cholesterol receptor gene, xanthomas, and family hx of premature coronary artery dz
Gnawing abdominal pain that is relieved by a light meal?
Peptic ulcer
H. pylori
Urease +
A child has pigmented mucocutaneous macules around the mouth and abdominal discomfort. Dz?
Peutz-Jeghers syndrome
AD mutation in serine thronine kinase 11 (STK11) on chr 19
Abdominal pain = hamartomatous polyps in the GI tract
A man has a tender mass on his butt that is growing. Bx = round cells with multiple mitoses, some cells have round clear cytoplasmic vacuoles scalloping the nucleus
Liposarcoma
Contains lipoblasts (produce non membrane bound cytoplasmic lipid)
Grow in depp tissue spaces of trunk and lower extremities
Older man has flaccid bullae that rupture easily. On IF immunoglobulin deposits are where?
Pemphigus vulgaris
IG deposits between keratinocytes, chicken wire pattern
desmogleins 1 and 3
A pt presents with tense bullae
Bullous pemphigoid
IgG against Basement Membrane, hemidesmosomes
Two risk factors for neonatal Respiratory Distress syndrome
Prematurity
Diabetic mom
What is a pancoast tumor?
An apical bronchogenic carcinoma that invades the brachial plexus
How does a pancoast tumor cause Horner syndrome?
Compression of the superior cervical ganglion
A pt presenting with diplopia, ptosis, and enlarged pupil has?
Oculomotor nerve lesion
Triad in Horner syndrome?
Misosis (constricted pupil)
ptosis (droopy lid)
anhidrosis (loss of sweating over half the face)
What is alcoholic cerebellar degeneration?
Chronic thiamin deficiency
Loss of purkinje cells in anterior lobes, cerebellar vermis,
Wide-based gait ataxia, truncal instability, intention tremor, “Parkinsonian tremor” of the hands
A pt is started on treatment for bipolar and presents a month later with DI syx. Urine fails to concentrate during water deprivation. Whats going on?
Lithium interferes with vasopressin’s action at the renal collecting ducts (neprogenic DI)
A 2 y/o pt presents with brisk rectal bleeding. FHx of IBD. Anemic on labs but all else is WNL
Meckel diverticulum
Failure of omphalomesenteric duct to obliterate
Heterotopic gastric mucosa
PAINLESS lower GI bleed
30 y/o pt presents with chest pain, syncope on exertion, systolic murmur that intensifies on standing. Fam Hx of sudden death during exercise
Hypertrophic Cardiomyopathy AD, more common in Blacks Mutation in beta-myosin heavy chain Morphology: LVH, LVOT obstruction Standing decreases preload
What is a split heart sound at the upper sternal border that is best heard on inspiration
S2
Aortic and pulmonic valve closure
Wide split due to lengthening of RV ejection time dealys closure of pulmonary valve
Disorders that can cause a wide split S2?
- RBBB
- Pulmonary stenosis
- Pulmonary arterial HTN
A pt with recurrent otits media, sinusitis, pneumococcal pneumonia and Low IgA. All other labs WNL
Selective IgA deficiency
Recurrent respiratory and GI infections (IgA = mucosal)
Increased risk of autoimmune dz
A pt with really high IgM but all other Ab’s low and B cell count WNL
CD40 ligand deficiency (Hyper IgM syndrome)
Pt with normal B cell count but universally low Ab production
Common variable immunodeficiency
Pt with high IgE but all other counts WNL
Job syndrome (hyper-IgE)
Pt with low B cell count and low levels of all Ab
X-linked agammaglbulinemia
Define accuracy
TP + TN/total
Area under the curve in a reciver operating characteristic (ROC) curves that plot sensitivity vs 1-specificity
Ideal test would have an AUC close to 1 (rectangular shape, largest slope)
Pt with an adnexal mass, ascites, and elevated cA-125?
Ovarian cancer
Family history of colon, ovarian, and endometrial cancer in first degree relatives?
Lynch syndrome
AD
Mutation in mismatch repair genes (MSH2, MLH1, MSH6, PMS2) and microsatellite instability (MSI)
Dx with MSI and or Immunohistochemistry
A pt with a history significant for organ transplant has a Renal bx revealing obliterative vasculopathy of afferent arterioles. This is most likely a side effect of?
Tacrolimus
Immunosuppresive
Calcineurin inhibitorsin general cause a rise in BUN and creatinine which can lead to renal arteriolar vasoconstriction causing systemic HTN and long term use leads to obliterative vasculopathy, tubular vacuolization and glomerular scarring
A pt with a hx of HTN and Parkinsons presents with abdominal rebound, guarding and free air under the diaphragm likely has? What meds should be avoided?
Bowel perforation with peritonitis Avoid metoclopramid (used in vomiting, gastroparesis) because it can exacerbate or cause de novo parkinsons
In a setting of acute ischemia in the periphary (ie DVT) which ion will be increased in the extracellular space?
Potassium
ATP becomes depleted in ischemia and the Na/K pump is not able to maintain resting transmembrane potential differences. Extracellular Na+ leaks in and depolarizes cells, intracellular K+ leaks out. Extracellular increase K+ may enhance the depolarization of nociceptive nerves (pain)
Which 3 stimuli trigger renin release from juxtaglomerular cells?
- Decreased tubular NaCl (sensed by macula densa)
- Decreased pressure in afferent arteriole
- Sympathetic stimulation
Juxatglomerular cells contain a lot of protein
What is a cheap and easy way to measure the lecithin:spingomyelin ratio?
Add amniotic fluid to a well of ethanol and shake. Look for foam (foam stability index)
Homocystinuria is an ar disorder resulting from mutation in which gene?
Cystathionine-beta-synthase (CBS)
Unable to form cysteine
Buildup of methionine and homocysteins
Marfainoid habitus with downward dislocation of the lens?
Homocystinuria
Marfainoid habitus with upward dislocation of the lens?
Marfan
Why is heparin preferred over Warfarin in pregnant women requiring clotting prophylaxis?
Higher water solubility of Heparin
Water soluble materials (ie conjugated bili) cannot easily cross the placenta
Warfarin is lipophilic
HIV pt has decreased vision in one eye. On exam the retina has white opaque patches with hemorrhage at the retinal periphery in the left eye
CMV retinitis
CD 4
McArdle dz, Pompe dz, Cori dz, von Gierke dz are all caused by defects in which cellular process?
Glycogenolysis
A pt with spiked T waves, prolonged PR intervals, wide QRS, and slowed hr likely have?
Hyperkalemia
Caused by metabolic acidosis, potassium sparing diuretcs, beta-andrenergic antagonists
A pt with Graves dz has protrusion of the eyes due to?
- Glycosaminoglycan synthesis (ie hyaluronic acid) by by fibroblasts
Lymphocyte infiltration stimulate fibroblasts - Interstitial edema
Pt may feel grittiness or excessive tearing because the eyelid can’t cover the globe of the eye
The largest (and first) peak on jugular venous tracing correlates to?
RA contraction
A pt with worsening headaches, n/v has a tumor of the pineal gland are at risk of developing?
Parinaud syndrome: upward gaze palsy, absent pupillary light reflex, impaired convergence
Where are GI stem cells located?
crypts of Lieberkuhn
Why do pts with rotavirus infection have diarrhea?
Rotavirus destroys the small intestinal enterocytes. Loss of digestive enzymes (maltase, lactase, etc) causes malabsorption of simple sugars causing profuse watery diarrhea
A pt with cirrhosis due to HBV will have spherical nodules within the confines of fibrous septae on liver bx. What cell type is in the nodules?
Liver cells
Cirrhosis = diffuse parenchymal injury and fibrosis. The normal lobular architecture is replaced with regenerative nodules that contain proliferating liver cells
I a strain of S. pneumo acquired a mutation that codes for insertion of a methyl group into a pocket of the 23SrRNA of the 50S ribosomal subunit, it would become resistant to which abx?
Macrolides (Azithromycin)
These abx bind the 223s rRNA moiety of the 50S subunit and block translocation
An infant has a painless doughy mass above her left clavicle and a blowing systolic murmur over the cardiac apex
Cystic hygroma = lymphatics do not properly connect to the venous system, usually on the left side
Assoc with Chromosomal aneuploidies (Turner, trisome 13, 18, and 21)
In a neuronal stimulation study in which the researchers were playing with electrolyte concentrations, the first depolarization reached +40mV and the second only reaches +10mV. Why?
Decreased Na+ outside of the cell
Just remember, depolarization is dependent on Na
A pt presents with a 5 day history of a red rash on his hands, forearms, and legs following a camping trip. Raised erythematous spots and streaks. Dx?
Allergic contact dermatitis (poison ivy)
Type IV Hypersenstivity rxn
Streaky pattern suggests that the skin brushed across the plant
Individuals with splenectomies are at increased risk of sepsis due to?
Encapsulated bacteria (S. pneumo, H. flu, N. meningitidis)
Reasons:
1. Spleen hosts many monocytes
2. Contains about half of the Ig producing B cells in the body which are needed to opsonize Ab.
Why do sickle cell pts have splenic autosplenectomy?
Repeated infarctions during vasoocclusive crisis results in splenic fibrosis and autosplenectomy
Why do people develop lactose intolerance in adulthood?
Decreased gene expression
Only really need lactase in infancy when we are breastfeeding
A pt has a history of external radiation therapy for enlarged adenoids. What is he at risk of developing?
Thyroid carcinoma (usually papillary)
RF’s: Fam Hx, Radiation exposure, Nodules, cervical lymphadenopathy
Of all tissues in the body, thyroid is the most sensitive to radiation
a pt has inappropriate sexual activity, oral fixation, hyperphagia, placidity, amnesia
Kluver-Bucy syndrome
amygdala lesion, associated with HSV1 encephalitis
First line management of low back pain following physical activity?
NSAIDs
If it doesn’t resolve in 4-6 weeks consider work up for OA, cancer, osteromylitis, abscess etc
What other finding would you see in a pt with respiratory alkalosis?
High urine pH
The tubules will try to salvage H+ to normalize the blood pH and will excrete bicarb
How does cyclosporine improve graft acceptance following an organ transplant?
Inhibiting IL-2 transcription
Cyclosporin cinds cyclophilin forming a complex that inhibits calcineurin.
Normally after calcineurin in the T cell is activated it dephosphorylatedNuclear factor of activated T cells (NFAT) allowing NFAT to enter the nucleus and bind the IL-2 promotor
What does IL-2 do to T cells?
stimulates growth and differentiation of T cells
Cyclosporine targets calcineurin to inhibit IL-2 transcription and facilitate graft acceptance
A pt with a history of schizophrenia develops tardive dyskinesia. Why?
Long-term blockade of dopamine receptors in the nigrostriatal DA pathway causes upregulation and supersensitivity of postsynaptic DA receptors
Can d/c the antipsychotic temporarily the “reset” the number and senstivity of DA receptors, but some will be irreversible
A male pt presents with nasal stuffiness, intermittent dizziness, infertility due to retrograde ejaculation, FTT in childhood, boggy nasal mucosa. Congenital deficiency of DA beta-hydroxylase. What is he at risk of developing?
Orthostatic hypotension
Deficiency of Dopamine beta-hydroxylase means that the pt can’t produce NE or epi (DA -. NE -> epi). This dz is characterized by impaired sympathetic adrenergic activity
Kids - hypotension, ptosis, hypothermia
Adults - postural hypotension, exercise intolerance, nasal congestion, ejaculatory difficulties
Where is NE present?
sympathetic post ganglionic neurons
Where is epi present?
CNS, secreted by the adrenal medulla
Which lung volume will be increased in a pt with obstructive lung diz?
Residual volume
Which cellular proteins halt mitosis in contact inhibition of normal cells?
Cadherins and catenins
Malignant cells do not obey
When an oral polio vaccine reverts to active form, what can it cause?
Vaccine-associated paralytic poliomyelitis
Generally not seen in the developed world due to IPV use
On CT where will the SVC be in relation to the aorta?
To the right (pts right) of The asc. aorta (prone to compression by a mass in the right apex of the lung)
Asc aorta = anterior to the trachea
Pulmonary trunk to the left of the asc. aorta, anterior to the trachea
Esophagus is posterior to the trachea
Desc. aorta will be to the left of the trachea, esophagus and posterior to the pulmonic trunk
A pts with a mid shaft humerus fx involving the spiral groove will have likely damaged which nerve? And difficulty with which movments?
Radial n.
Wrist extension
NOTE: there would be sparing of the triceps brachii because the nerve fibers innervate that m. before the muscle enters the radial groove
A woman is evaluated for prolonged bleeding episodes. Her brother has hemophilia but her symptoms appear to be milder. Why?
Skewed X inactivation
Which DNA virus is the only one that will replicate in the cytoplasm?
Poxvirus
Which is the only RNA virus that will replicate in the nucleus?
Orthomyxovirus
A pt presents with malaise, HA, hyperactivity and painful pharyngeal contractures. Pt dies days later. Autopsy demonstrates widespread inflammatory rxn in the brain and eos round inclusions in the hippocampus. Dx?
Rabies
eosinophilic cytoplasmic inclusin in hippocampus = Negri body (pathogmonic)
syx = malaise followed by painful pharyngeal muscle spasms, hydrophobia, ascending paralysis
Researchers place a clip on the Left renal a. to reduce the diameter by 75%. What change is likely to be seen?
Increased FF due to decreased renal perfusion
Reduced GFR is sensed a a drop in NaCl by the macula densa in the distal tubule and:
1. Dilates afferent arteriol (improve GFR and RBF)
2. Efferent arteriolar constriction (improves GFR and RBF)
When perfusion decreases RPF falls greater than GFR due to GFR autoregulation.
FF = GFR/RPF
A pt with orthostatic hypotension probably has understimulation of which receptor?
alpha1
As a pt stands blood will pool in the feet and the carotid baroreceptor will increase sympathetic tone to increase hr and SVR to maintain preload. This is mediated through stimulation of alpha1
A pt with unresponsive psoriasis is interested in a treatment option with strong teratogenic potential and she is required to use a reliable contraceptive and take frequent pregnancy tests while on the medication. What is the drug?
Acitretin (retinoid)
Promote cellular differentiation, immunomodulatory, and anti-tumor effects.
Must abstain from alocohol (increases half life of med) and cannot conceive for 3 years after stopping the drug)
A strain of step is resistant to gentimicin but when penicillin is added, the intrabacterial concentration of gentamicin increases. what is the mechanism of resistance?
Poor drug penetrance into the cell
Adding penicillin makes the cell wall unstable and allow more gentamicin to enter. Aminoglycosides enter the bacterial membranes through porin channels in an energy dependent mechanism
-mycin
Macrolide
Bind 50 S
-micin
Aminoglycoside
Bind 30S
Exception is streptomycin
A 76 y/o male has lower extremity edema, weight game. 80py and CXR shows right sided perihilar mass. 5 g of protein on 24hr urinary collects and renal bx show thickened GBM with Jones methenamine silver staining. Dx?
Membranous glomerulonepritis
Most common nephropathy IC deposition in subepithelium
Usually idiopathic but can be associated with tumors, chronic infection, autoimmune dz
A pt has a mass in her rectum and lesions suspicious for metastasis in the right and left lobes of the liver, but none in the lungs or bone. What explains this distribution?
Venous drainage by the inferior mesenteric v. takes cells from the rectal carcinoma to the portal venous system
Tissue above dentate line drains through superior rectal v. -> inferior mesenteric v. -> portal venous system
Tissue below the dentate line would have drained into the systemic circulation via the internal illiac v.
Proximal Rectal carcinomas will first metastasis to?
The liver via the inferior mesenteric v. which drains into the portal venous system
Distal rectal carcinomas (near the anus) will metastasis to?
The lungs initially because the middle and inferior rectals v. drains into the caval system via the internal illiac
An older woman presents with a pruritic rash on both extremities during the winter. Rash is scaly but does not look like psoriasis. Dx and Tx?
Xerosis - common in elderly in the winter months
Tx - apply moisturizers esp after bathing, lukewarm showers.
Why can’t skeletal muscle produce glucose from glycogen?
Lacks Glucose 6 phosphatase. Muscle glycogen is shunted into glycolysis to produce energy.
Pts with McArdle dz have glycogen accumulation in the muscle due to deficient myophosphorylase
Why do McArdle pts have improved exercise tolerance following a brief period of rest? “second wine phenomena”
increased blood flow to the muscle will deliver free fatty acids to the muscle for energy
A pt with DKS is started on IV fluids and insulin infusion. Which molecule will rapidly rise in the liver?
Fructose-2,6,-bisphosphate
Enhances PFK1 activity in glycolysis
How does glucagon promote gluconeogenesis?
Activates enzymes to degrade F-2,6-BP so that PFK1 stimulation will decrease
Which amino acids are non polar?
Alanine Glycine Isoluecine Leucine Methionine phenylalanine Proline Valine A girl in love may play virginal
A typical mucormycosis infection will be located in?
The cavernous sinus
Unique things:
1. Internal caroticd, CN III, CN IV, CN V1, CN V2, CN VI all pass through it
2. Drains veins from the brain and the facial v.
Infection can cause valveless facial venous return and thrombosis
Lateral gaze palsy is often an early sign of mucor due to CN VI involvement
A 24 year old male presents with bilateral parotid swelling and a swollen scrotom. He did not receive child hood vaccines. He has lost his sex drive. Dx and Tx?
Mumps
Orchitis can cause seminiferous tubule atrophy leading to infertility and leydig cell atrophy. Loss of leydig cells reduces testosterone production
Tx - exogenous testosterone
A pt with urethral discharge and orchitis has a swab positive for numerous PMNs but no organisms. Tx?
Nongonococcal urethritis, likely due to Chlamydia
Neisseria would have GN intracellular diplococci
Tx - azithromycin - inhibits protein synthesis becase Chlamydia has an atypical cell wall
A pt with syphillis is given penicillin G and probenecid. Why was probenecid added?
Inhibit renal tubular secretion of penicillin
Probenecid inhibits organic anion transporters
Decreases penicilline secretion but decreases uric acid reabsorption
Teenager presents with HTN and hypokalemia and low cortisol excretion. Tx with cortisol corrects her HTN. Deficiency?
17 alpha hydroxylase deficiency
Accumulation of progesterone
expect her to have amenorrhea with lack of secondary sex characteristics
A pt losses consciousness during a coughing fit. Why?
Decreased venous return to the heart
Tends to happen in overweight men with COPD
Can also be due to carotid sinus stimulation which increases vagal tone and bradycardia
A young boy has developed several tumors. His cells are exposed to environmental factors and the DNA is extracted. Dimerized pyrimidine endonuclease activity is much higher on his extracted DNA than a healthy pt. Dx?
Xeroderma pigmentosum
ar
Failure in nucleotide excision repair. Usually defetive in UV specific endonuclease, but can be any
UV endonuclease targets covalently bound pyrimidines
Defect in ATM gene leads to defect in DNA repair following ionizing radiation
Ataxia-telangiectasia
Telangiectasis in the eyes, ears, severe ataxia, predisposition to lymphoproliferative malignancy
45 y/.o AA has unilateral submandibular lymphadenopathy. Bx = small lymphocytes with cleaved nuclei. Overexpress bcl-2
Follicular lymphoma 2 populations of cells on bx possible: 1. Small cleaved cells without nucleoli 2. Larger, non-cleaved cells with multiple nucleoli bcl-2 = t14;18, inhibits tumor apoptosis
Child with ascites, abdominal mass arising in the distal ileum, cecum or mesentery. Bx = basophilic, vacuolated, mitotic cells in “starry sky” apprearance. Myc overexpression
Burkitt lymphoma
Burkitt cells = mitotic cells with overall “starry sky” appearance due to presence of scattered macrophages
46 y.o homeless man presents with symptoms of cirrhosis. He has skin lesions on the trunk, face, and upper arms that are red and contain multiple dilated blood vessels radiating from a single central vessel. What causes this?
Spider angiomata, quantity and size correspond to dz severity
Also seen in pregnancy or malnourished folks
Caused by Estrogen excess due to decreased metabolism by the failin liver, decreased sex hormone binding globulin, decreased metabolism of androgens (converted to estrogen by aromatase)
In NFT-1, the skin nodules are due to proliferation of which cell type?
Schwann cells
Neurofibromas = loose disorganized proliferations of Scwann cells (elongated, wavy cell with spindly nuclei), fibroblasts and neurites
What rule is helpful when determining the percentage of people that are 1 vs 2 vs 3 deviations from the means?
68/95/99 rule
Remember this includes the % about and below
So 1 SD = 16% more than one SD above the mean, and 16% more than one SD below the mean
A 20 y/o woman is presenting with worsening pelvic pain. Laproscopy reveals thin, filmy adhesions throughout the pelvis, nodular implants in the posterior cul de sac. Blue papules are on the bladder and R ovary. Dx and additional risk for?
Endometriosis - ectopic growth of endometrial glands and stroma
At risk of infertility - surgical resection can lyse the adhesions and improve fertility
A HIV + male has blood in his stool. CD = 360. Sigmoidoscopy finds friable inflamed mucosa in the rectum and sigmoid colon. Bx = PMNs inthe crypt lumina
Ulcerative colitis
Continuous lesion, infiltrate in mucosa and submucosa only, PMG accumulation
No association with HIV
38 year old woman presents with amenorrhea. High FSH, low estrogen and a history of ALL
Primary ovarian insufficiency (premature ovarian failure)
Amenorrhea in women under 40 due to inadequate supply of follicles or premature depletion. Chemo augments follicular atresia (apoptosis of follicles)
How do agglutination inhibition reactions work?
The sample is incubated with Ab against an Ag of interest. Then this is added to a reagent that has latex particles coated with the Ag of interest. If it agglutinates the test is negative because the Ab are free to bind the latex particles. If it does not agglutinate the test is positive because the Ab have been saturated with the Ag of interest in the sample
A pt is started on a medication following a major depressive episode and presents with hyperthermia, flushing, mydriasis, dry mouth, constipation, urinary retention, tachycardia. What medication was he put on?
TCA’s (amitriptyline)
Affinity for muscarinic ACh receptors producing anticholinergic effects
Also alpha antagonistic property causes orthostatic hypotension
Which inheritance pattern produces dz like angelman syndrome or prader willi?
Uniparental disomy or microdeletion
A pt with neonatal hypotonia, hyperphagia/obesity, short stature, small hands/feet, hypogonadism, dysmorphic facies, intellectual disability
Prader-Willi
Loss of paternal chr 15
A pt with epilepsy, ataxic gait, tremors, poor motor/language development, inappropriate laughter, intellectual disability
Angelman syndrome
Loss of maternal chr 15
What is uniparental disomy?
Defect in meiotic division resulting in 2 copies of a chromosome from one parent and none from the other parent
Stents placed into the coronary a. are coated with paclitaxel, why?
Inhibit intimal hyperplasia by binding b-tubulin and preventing microtuble breakdown arresting the cell in M phase. This decreases stent thrombosis
A pt in DKA is given IV fluids and insulin. What is the effect of GLUT4 in the pts adipose?
Increased translocation of the protein to the cell membrane
Glut 4 = passive transport
Insulin binds its receptor -> activates tyrosine kinase -> activates PI3K second messenger pathway which translocates GLUT 4
In a distal clavicle fx, which muscle will pul the bone fragment inferolaterally?
Deltoid
Fx displacement increases risk of nonunion
A pt has right lower extremity numbness and pain and hx of chronic back pain. Decreased sensation on laterl right leg, dorsal foot, unable to walk on heels. Patellar reflex = 2+ bilaterally.
Common peroneal n.
Pinched at the fibular neck (or knee high boots)
“Foot drop” = inability to walk on heels becaus common peroneal injury also affects the deep peroneal n.
Sensory loss due to superficial peroneal n.
What is activated immediately after ligand binding at a G protein coupled receptor?
G protein
ligand binds -> GPCR changes conformation -> activates GTPase -> Activate secondary messenger (adenylate cycles, IP3 etc)
A y/o presents with confusion, lethagry, vomiting. High blood ammonium and increased urinary orotic acid. Dx?
Ornithine transcarbamoylase deficiency
Carbamoyl phosphate accumulatesand is converted to orotic acid in the pyrimidine pathway
Cells exposed to prolyl hydroxylase inhibitor will have a defect in?
Triple helix formation of collagen molecules (procollagen)
Occurs in RER
Requires vitamin C
Deficiency in lysyl oxidase would cause?
Decreased collagen cross-linking
Typical transduction is associated with viruses with which life cycle?
Lytic
Lysogenic may carry some bacterial genes that were adjacent to the viral genome when it was inserted in the bacterial genome