Uworld SA 2 Flashcards
(290 cards)
1
Q
Inheritance pattern of Familial hypercholesterolemia?
A
AD
Defect LDL cholesterol receptor gene, xanthomas, and family hx of premature coronary artery dz
2
Q
Gnawing abdominal pain that is relieved by a light meal?
A
Peptic ulcer
H. pylori
Urease +
3
Q
A child has pigmented mucocutaneous macules around the mouth and abdominal discomfort. Dz?
A
Peutz-Jeghers syndrome
AD mutation in serine thronine kinase 11 (STK11) on chr 19
Abdominal pain = hamartomatous polyps in the GI tract
4
Q
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
A
Liposarcoma
Contains lipoblasts (produce non membrane bound cytoplasmic lipid)
Grow in depp tissue spaces of trunk and lower extremities
5
Q
Older man has flaccid bullae that rupture easily. On IF immunoglobulin deposits are where?
A
Pemphigus vulgaris
IG deposits between keratinocytes, chicken wire pattern
desmogleins 1 and 3
6
Q
A pt presents with tense bullae
A
Bullous pemphigoid
IgG against Basement Membrane, hemidesmosomes
7
Q
Two risk factors for neonatal Respiratory Distress syndrome
A
Prematurity
Diabetic mom
8
Q
What is a pancoast tumor?
A
An apical bronchogenic carcinoma that invades the brachial plexus
9
Q
How does a pancoast tumor cause Horner syndrome?
A
Compression of the superior cervical ganglion
10
Q
A pt presenting with diplopia, ptosis, and enlarged pupil has?
A
Oculomotor nerve lesion
11
Q
Triad in Horner syndrome?
A
Misosis (constricted pupil)
ptosis (droopy lid)
anhidrosis (loss of sweating over half the face)
12
Q
What is alcoholic cerebellar degeneration?
A
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
13
Q
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?
A
Lithium interferes with vasopressin’s action at the renal collecting ducts (neprogenic DI)
14
Q
A 2 y/o pt presents with brisk rectal bleeding. FHx of IBD. Anemic on labs but all else is WNL
A
Meckel diverticulum
Failure of omphalomesenteric duct to obliterate
Heterotopic gastric mucosa
PAINLESS lower GI bleed
15
Q
30 y/o pt presents with chest pain, syncope on exertion, systolic murmur that intensifies on standing. Fam Hx of sudden death during exercise
A
Hypertrophic Cardiomyopathy AD, more common in Blacks Mutation in beta-myosin heavy chain Morphology: LVH, LVOT obstruction Standing decreases preload
16
Q
What is a split heart sound at the upper sternal border that is best heard on inspiration
A
S2
Aortic and pulmonic valve closure
Wide split due to lengthening of RV ejection time dealys closure of pulmonary valve
17
Q
Disorders that can cause a wide split S2?
A
- RBBB
- Pulmonary stenosis
- Pulmonary arterial HTN
18
Q
A pt with recurrent otits media, sinusitis, pneumococcal pneumonia and Low IgA. All other labs WNL
A
Selective IgA deficiency
Recurrent respiratory and GI infections (IgA = mucosal)
Increased risk of autoimmune dz
19
Q
A pt with really high IgM but all other Ab’s low and B cell count WNL
A
CD40 ligand deficiency (Hyper IgM syndrome)
20
Q
Pt with normal B cell count but universally low Ab production
A
Common variable immunodeficiency
21
Q
Pt with high IgE but all other counts WNL
A
Job syndrome (hyper-IgE)
22
Q
Pt with low B cell count and low levels of all Ab
A
X-linked agammaglbulinemia
23
Q
Define accuracy
A
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)
24
Q
Pt with an adnexal mass, ascites, and elevated cA-125?
A
Ovarian cancer
25
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
26
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
27
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
```
28
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)
29
Which 3 stimuli trigger renin release from juxtaglomerular cells?
1. Decreased tubular NaCl (sensed by macula densa)
2. Decreased pressure in afferent arteriole
3. Sympathetic stimulation
Juxatglomerular cells contain a lot of protein
30
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)
31
Homocystinuria is an ar disorder resulting from mutation in which gene?
Cystathionine-beta-synthase (CBS)
Unable to form cysteine
Buildup of methionine and homocysteins
32
Marfainoid habitus with downward dislocation of the lens?
Homocystinuria
33
Marfainoid habitus with upward dislocation of the lens?
Marfan
34
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
35
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
36
McArdle dz, Pompe dz, Cori dz, von Gierke dz are all caused by defects in which cellular process?
Glycogenolysis
37
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
38
A pt with Graves dz has protrusion of the eyes due to?
1. Glycosaminoglycan synthesis (ie hyaluronic acid) by by fibroblasts
Lymphocyte infiltration stimulate fibroblasts
2. Interstitial edema
Pt may feel grittiness or excessive tearing because the eyelid can't cover the globe of the eye
39
The largest (and first) peak on jugular venous tracing correlates to?
RA contraction
40
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
41
Where are GI stem cells located?
crypts of Lieberkuhn
42
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
43
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
44
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
45
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)
46
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
47
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
48
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.
49
Why do sickle cell pts have splenic autosplenectomy?
Repeated infarctions during vasoocclusive crisis results in splenic fibrosis and autosplenectomy
50
Why do people develop lactose intolerance in adulthood?
Decreased gene expression
| Only really need lactase in infancy when we are breastfeeding
51
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
52
a pt has inappropriate sexual activity, oral fixation, hyperphagia, placidity, amnesia
Kluver-Bucy syndrome
| amygdala lesion, associated with HSV1 encephalitis
53
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
54
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
55
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
56
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
57
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
58
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
59
Where is NE present?
sympathetic post ganglionic neurons
60
Where is epi present?
CNS, secreted by the adrenal medulla
61
Which lung volume will be increased in a pt with obstructive lung diz?
Residual volume
62
Which cellular proteins halt mitosis in contact inhibition of normal cells?
Cadherins and catenins
| Malignant cells do not obey
63
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
64
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
65
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
66
A woman is evaluated for prolonged bleeding episodes. Her brother has hemophilia but her symptoms appear to be milder. Why?
Skewed X inactivation
67
Which DNA virus is the only one that will replicate in the cytoplasm?
Poxvirus
68
Which is the only RNA virus that will replicate in the nucleus?
Orthomyxovirus
69
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
70
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
71
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
72
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)
73
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
74
-mycin
Macrolide
| Bind 50 S
75
-micin
Aminoglycoside
Bind 30S
Exception is streptomycin
76
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
77
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.
78
Proximal Rectal carcinomas will first metastasis to?
The liver via the inferior mesenteric v. which drains into the portal venous system
79
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
80
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.
81
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
82
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
83
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
84
How does glucagon promote gluconeogenesis?
Activates enzymes to degrade F-2,6-BP so that PFK1 stimulation will decrease
85
Which amino acids are non polar?
```
Alanine
Glycine
Isoluecine
Leucine
Methionine
phenylalanine
Proline
Valine
A girl in love may play virginal
```
86
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
87
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
88
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
89
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
90
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
91
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
92
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
93
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
94
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
```
95
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
96
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)
97
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
98
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
99
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
100
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
101
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)
102
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
103
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
104
Which inheritance pattern produces dz like angelman syndrome or prader willi?
Uniparental disomy or microdeletion
105
A pt with neonatal hypotonia, hyperphagia/obesity, short stature, small hands/feet, hypogonadism, dysmorphic facies, intellectual disability
Prader-Willi
| Loss of paternal chr 15
106
A pt with epilepsy, ataxic gait, tremors, poor motor/language development, inappropriate laughter, intellectual disability
Angelman syndrome
| Loss of maternal chr 15
107
What is uniparental disomy?
Defect in meiotic division resulting in 2 copies of a chromosome from one parent and none from the other parent
108
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
109
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
110
In a distal clavicle fx, which muscle will pul the bone fragment inferolaterally?
Deltoid
| Fx displacement increases risk of nonunion
111
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.
112
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)
113
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
114
Cells exposed to prolyl hydroxylase inhibitor will have a defect in?
Triple helix formation of collagen molecules (procollagen)
Occurs in RER
Requires vitamin C
115
Deficiency in lysyl oxidase would cause?
Decreased collagen cross-linking
116
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
117
Following an MVA a pt has displacement of the innermost portion of the right temporal lobe under the tentorium cerebelli. What structure is at risk for compression?
Oculomotor n. - fixed dilated pupil on ipsilateral side (interrupts PS activity
Uncal herniation
118
Pt presents with nausea, dizziness, abdominal pain, and chronic back pain. She notes that her bf recently broke up with her. PE is normal. Dx?
Somatic symptom disorder
Excessive concern about multiple somatic symptoms, overestimate the seriousness, not reassured by negative workup, allow dz to overwhelm their relationships.
119
Pt has nuerologic symptoms and findings incompatible with recognized neurological conditions following an acute stressor (ie breakups)
Conversion disorder
120
A 50+ y/o female has low back pain following trauma. She also takes ranitidine for GERD and a BMI of 19. Her back pain is likely due to hypofunction of the?
Ovary (low estrogen)
| Osteoporosis (vertebral fx following minor trauma)
121
An older pt has been drinking daily since his wife passed away and is presenting with memory difficulties, fabricating stories, slow unsteady gate. Dx?
Korsakoff syndrome
Thiamine deficiency
Confabulation = unintentional fabrication of stories/memories
122
Pt with gradual onset of confusion to place and time, anomia, failure to adhere to social normal, apathy, change in personality or behavior
Pick dz
| Frontotemporal dementia
123
Teenage girl presents with amenorrhea, lack of secondary sexual characteristics, HTN. Dx?
Effect on: renin, ACTH, LH?
17 alpha hydroxylase deficiency
Renin low
ACTH, LH high
hypertensive, hypokalemic normal genitalia at birth
124
2 y/o presents with lethargy and seizures, hepatomegaly. Labs: hypoglycemia, low ketone levels, elevated octanoulcarnitine
Medium chain acyl coenzyme A dehydrogenase (MCAD) deficiency
ar, hets have mild dz
hypoketotic hypoglycemia
Unable to degrade medium-length fatty acids (6-12C). Occurs in childhood following fasting or metabolic stress
125
Pt has a germline mutation that is a loss of function of a proteins that detects and corrects base pair errors in microsatellites. Most likely to develop which condition?
Colorectal carcinoma
Lynch syndrome - AD, risk of colon, endometrial, and ovarian cancer
Microsatellites = 2-5 base repeats that are highly susceptible to mutation and are repaired by DNA mis-match repair genes (MSH1 etc)
126
A pt with Potts dz has an abscess in the Psoas m. Where is this infection most likely to migrate to?
```
The groin
The psoas (T12 - L4) does NOT enter the true pelvis
```
127
A 30 year old pt presents with a rash consistent with Shingles and he travels frequently for his job. What other viral infection could have predisposed him to Varicella reactivation?
HIV
RFs for Varicella reactivation = age and immunosuppression
young pt with Shingles should be tested for HIV
128
A man with HTN is started on lisinopril. What would happen to his levels of: renin activity, Angiotensin 2?
Increased renin activity
Decreased Angiotensin 2
Angiontensin 2 inhibits renin release so ACEI interrupt this feedback loop
129
When a recombinant protein vaccine is given to a group of healthy volunteers, some individual with a particular HLA haplotype do not mount an effective IgG Ab response. Why?
Defect in Ag presentation by B lymphocytes
MHC II are on macrophages, DC and B cells and would be used for extracellular Ag
Each MHC variant has different aa sequence and therefore range of proteins they can bind
130
Why do pts with advanced pneumonia develop ARDS?
Right to left shunting leading to hypoxemia
| Increased alveolar dead space due to proteinaceous fluid, blood, and cellular debris
131
A strain of HIV has a point mutation that makes it resistant to ritonavir. What other drug is this strain likely to be resistant to?
Protease inhibitors prevent the cleavage of gag and pol gene products.
-navir
Would also be resistatnt to:
Darunavir, Atazanavir, indinavir, ritonavir
132
What is the function and use of Tenofovir?
Nucleotide RT inhibitor
| Also Abacavir
133
A pt is dx'd with hemangioblastoma in the cerebellum. What is he at risk of developing?
Renal cell carcinoma
Pt has Von Hippel-Lindau (AD, chr 3) characterized by hemangioblastoma in the cerebellum, cysts in the kidneys and pancrease, pheochromocytome, and RCC
134
If an adult produces abn low amounts of 2,3-bisphophoglycerate, the binding properties of Hgb will most closely resemble?
Fetal Hemoglobin
2,3-BPG binds to deoxy hemoglobin to facilitate oxygen dissociation. If 2,3 BP is absent that the Hgb affinity for oxygen will be really high
135
In Wilson's dz where does the copper deposit in the eye?
Descemet's membrain in the Cornea
Kayser-Fleischer rings
ar, present in 30-40's
Cirrhosis, dystonia, tremor, dysarthria, dysphagia
136
Which enzyme in activated PMN's will be able to destroy bacterial cell membranes?
NADPH oxidase, Deficient in Chronic granulomatous dz
membrane protein in the phagosome responsible for oxidative burst by forming superoxide (transfers ions from NADPH to oxygen). After oxidative damage, there is fusion of azurophilic granules to introduce proteases, defensins, and myeloperoxidase
137
Which enzyme in phagocytic cells combines with hydrogen peroxide to form hypochlorous acid that cause further oxidative damage?
Myeloperoxidase
138
A pt has decreased MCAD activity and is found to have a polypeptide chain with the same number of residues as the wild type enzyme but minimal catalytic activity. Has 12 exons and 11 introns. Which mutation causes the dz?
Missense mutation
Codon change causing an aa substitution in exon 11
Exons are expressed
139
28 y/o female presents during pregnancy with a new breast lump that is mobile, nontender, and firm. Following delivery mass decreases in size but remains firm, mobile, non-tender. Dx?
Fibroadenoma
| Proliferation of stromal and ductal elements surrounded by a fibrous capsule
140
Young males has a bx of a skin lesion that demonstrates dermoepidermal junction aggregates of large cells that fuse with adjacent nests. Irregular nuclear contours, hyperchromasia, round or spindle shaped. Mutation in chr 9p21. Predisposed to developing?
Melanoma
This is a dysplastic nevus with architectural and cytologic atypia. Nest of nevomelanocytes with angulated hyperchromatic nuclei and bridging with nests.
Dyplastic nevi is associated with melanoma susceptipility on CDKN2A found in 9p21
CDKN2A encodes a cyclin-dependent kinase inhibitor, stops cell cycle progression in b/w G1 and S by binding CDK4
141
65 y/o presents to ED with severe chest pain. Smokes and drinks daily. 180/120, 90/min. No EKG changes. Cardiomegaly and abn aortic contour, widened superior mediastinum on CXR Dx?
Aortic dissection
| Chronic HTN and Marface predispose to dissection
142
Which drug potentiates the action of GABA but is unaffected by flumazenil?
Barbiturates
| phenobarbital
143
Which drug potentiates the action of GABA but its effect is reduced by flumazenil?
Benzos
| Flumazenil competitively inhibits benzos
144
What is the function of flumazenil?
Benzodiazepine receptor antagonist that is used to treat benzo OD or excessive drowsiness related to benzo use
145
```
During a stress test a pt has:
increased hr
decreased LV end systolic volume
increased LV end diastolic volume
Unchanged LV end diastolic pressure
```
Normal response to exercise
Heart meets increased demand for blood flow by increasing CO (hr x sv). During exercise hr increases as dose SV by (Increasing preload, decreasing afterload)
146
A pt presents with difficulty walk and frequent falls. He is an alcoholic, broad unsteady gate, can't walk in a straight line, unable to perform shin-to-heel testing. Dx?
Alcoholic cerebellar degeneration
loss of purkinje cells in the vermis presenting with truncal ataxia
Upper limb coordination (finger to nose test) is often spared
147
What structures arise from the Prosencephalon?
Forebrain
1. Telencephalon - Cerebral hemispheres, lateral ventricles
2. Diencephalon - Thalamus, 3rd ventricle
148
What structures arise from the mesencephalon?
Midbrain
| Midbrain and aqueduct
149
What structures arise from the Rhomboencephalon?
Hindbrain
1. Metencephalon - Pons, cerebellum & upper 4th ventricle
2. Myelencephalon - Medullar and lower 4th ventricle
150
A protein in the pancrease is found to be abundant in arginine and lysine. It has a 30-residue- alpha helical segment with a leucine residue at every 7th position. What is it?
Transcription factor
Contains a leucin zipper (2 alpha-helical monomers forming a dimer).
Other motifs found in eukaryotic DNA binding proteins are the helix-loop-helix and zinc finger
Need basic (+) regions to bind the negative phosphate backbone of DNA
151
A 34 y/o male presents with fevers fatigue, weight loss, lumps in his neck, night sweats. Recently returned from a project in south asia. Negative HIV and owl-eye cells on bx
Hodgkins lymphoma
Painless lymphadenopathy, B symptoms, Reed-Sternberg cell (large cell with abundant cytoplasm, bilobed vesiculated nucleus, prominent eos)
EBV/CMV would have other abn lymphocytes on smear
152
Angiotensin II binds transmembrane G protein couple receptor in zona glomerulosa, receptor changes conformation, G protein activates and hydrolyzes membrane-bound phospholipids. What happens next?
Ca2+ efflux from the ER
Ag II activates Gq -> phospholipase C -> IP3 and DAG.
IP3 - releases stored calcium from the ER
DAG - activates Protein kinase C which phosphorylates other regulatory proteins and hydrolyzes phospholipids
153
Where does de novo pyrimodine synthesis begin?
Carbomyl phosphate synthetase 1 catalizes the first step in de novo pyrimodine synthesis in the cytosol by combining glutamine, CO2, and 2 ATP to form carbamoyl phosphate
carbamoyl phosphate synthetase I is active in the mitochondria and facilitates the urea cycle
154
32 y/o female presents with abd pain, urinary frequency and nausea. While supine she is asked to flex her right hip against resistance which elicits extreme pain. Dx?
Ilipsoas test
| + sign = inflammation of the psoas or overlying parietal peritoneum. Assoc with abscesses and appendicitis
155
34 y/o homeless man is a severe alcoholic presents with dyspnea, peripheral edema, parasoxymal dyspnea. At autopsy large cardiac ventricles, myocardial hypertrophy and interstitial fibrosis. Dx?
Dilated cardiomyopathy
assoc with alcohol abuse esp in pts with mutations in alcohol dehydrogenase or the DD isoform of ACE
Large heart, large ventricles, but normal ventricular thickness
156
From the outside in, what are the layers of a typical fungus (cryptococcus) and which drugs target each layer?
```
Capsule
Cell wall (caspofungin)
Cell membrane (Amphotericin, nystatin, azoles)
Nucleus (DNA/RNA synthesis, Flucytosine)
Griseofulvin targets the mitotic spindle
```
157
46 y/o male presents with fatiguability, weight gain, lower extremity edema over 2 weeks
200/120, breath sounds on auscultation. 1+ pitting edema. Labs: Serum Cr. 3.1. Urinalysis: 3+ blood, 2+ protein. Bx = IF staining is linear
Antinglomerular basememtn membrane dz
| If he also had lung involvement = Goodpasture's
158
A 24 y/o female presents with irregular bleeding following a D&C for a miscarriage last year. U/S reveals central heterogenous mass in the uterus with numberous discrete anechoic spaces. After D&C the specimen reveals edematous chorionic villi, p57 -. Dx?
Complete mole
Abn proliferation of placental precursors (Cytotrophoblast
and syncytiotrophoblass)
Absence of embryonic or fetal tissue due to paternal imprinting (46XX, 46XY derived entirely from sperm)
Partial mole would be p57+ b/c this gene is maternally expressed
Presents with: vaginal bleeding, extremely high b-hCG, "snowstorm" patteron on U/S
159
A 32 y/o presents with a history of several renal calculi and passes a calcium oxalate stone. He is schedule for a parathyroidectomy. 1 gland is large but the other 3 are small and atrophic. Why?
Recurrent nephrolithiasis and a single enlarged parathyroid gland = parathyroid adenoma
Most common cause of primary hyperparathyroidism (bones, stones, and groans)
Other 3 lobes of the parathyroid are small due to the Negative feedback of their hypercalcemic state secondary to excess PTH
160
A 17 y/o girl with comedonal acne is given topical tretinoin. How does this improve her skin?
Retinoids (vitamin A analogs) Normalizes follicular keratinization, decrease sebum production, increase cellular turnover (reduces hyperkeratinization, opens black heads)
161
What activity or finding is the greatest risk factor for ischemic heart dz?
Smoking
1. Promotes atherosclerosis
2. Promotoes platelet aggregation
2-3x increased risk of ischemic heart dz
162
A 63 y/o man presents with dysphagia. PMH of GERD. Bx finds an adenocarcinoma of the distal esophagus and an esophageal resection is planned which includes a dissection between the esophagus and the right crus of the diaphragm. What structure is at risk of injury?
Vagus trunks
The esophageal hiatus (T10) contains:
Esophagus
Ant and post trunks of the vagus n.
163
A pt presents with stable angina and is started on amlodipine. What is its action?
Dihydropines (amlodipine, nifedipine, felodipine tc) target smooth muscle and promote vasodilation, decrease afterload.
164
A 12 y/o is being evaluated for T1DM. An oral glucose test shows a fasting glucose of 107 and 2-hour posprandial glucose of 204. What enzyme is he deficient in?
Glucokinase
Expressed in pancreatic cells where it can regulate insulin secretion and convertes glucose to G6P.
Liver uses glucokinase to make glycolygen
165
What is MODY?
Maturity-onset diabetes of the young
AD
Impaired insulin secretion with minimal or no defects in insulin action due to mutation in the glucokinase gene or transcription factors.
Mild dz, no tx required
166
Where is hexokinase expressed?
Most cell types except liver and pancreas. Higher affinity for glucose
167
Where is glucokinase expressed?
Liver and pancreas
168
A 5 mo old has a tonic clonic seizure that presented as she was trying to feed him. Pt has a big belly but weight/length is
Von-Gierke
Defect in Glucose-6-Phosphatase
Presents at around 6 mo when feedings are spread out
Severe fasting hypoglycemia, lactic acidosis
Poor growth, hepatomegaly.
Tx - frequent oral glucose, avoid fructose and galactose since they cannot be converted to free glucose
169
A 4 month old is brought to clinic for abn development. PE: hypotonia of face and extremities, large heart. Muscle bx shows intracellular material that is acid-Schiff positive. Dx?
Pompe dz
Deficient acid alpha-glucosidase (acid maltase), normal enzyme degrades glycogen trapped in lysosomes. In pompe dz glycogen accumulates in lysosomes (periodic acid-Schiff + material) causes hypotonia, macroglossia, hypertrophic cardiomyopathy
This is the only glycogen storage dz that has a defective enzyme in the lysozyme and presents with cardiomegaly
170
A 21 year old man presents with impotence. Low libido, difficulty acheiving and sustaining erection, no nocturnal erections. Sparse body hair, gynecomastia, small/firm testes. High LH, low test, normal prolactin. Dx?
Klinefelter, 47XXY
Gynecomastic, adipose at hips/thighs, sparse body hair, primary hypogonadism, increased bone length, azoospermia, intellectual impairment.
confirm dx with chromosome analysis
atrophied hyalinized seminiferous tubules causing small firm testes and low inhibin. Leydig cells ar abn causing low test. Lack of feedback inhibition causes high FSH/LH
171
In males Testosterone provides negative feedback to GNRH to decrease?
LH
172
In males, Inhibin provides negative feedback to?
FSH
173
A pt presents with DIC secondary to sepsis. What lab findings would be expected for:
Fibrinogen, PTT, PT, Platelets
Fibrinogen and platelets - decreased
PTT and PT - increased
DIC: prolonged PT, thrombocytopenia, increased fibrin degradation products, schistocytes in the setting of microangiopathic hemolytic anemia (MAHA)
174
A pt on warfarin has an INR of 1.2 (therapeutic range 2.5-3.5). Why is her INR so low?
Drugs that activated CYP450
| Carbamazepine, Ginseng, Spinach, OCP's, Phenobarbital, Rifampin, St. John's wort
175
46 y/o man presents with low back pain following activity. PE + straigh leg test, decreased ankle reflex, S1 nerve root impingement. What is the most likely cause of his pathology?
Acute lumbosacral radiculopathy due to vertebral disc herniation (disrupted annulus fibrosus and subsequent Prolapsed nucleus pulposus)
Most resolve in wks - mo
176
Following an argument a 67 y/o man became unresponsive. 188/104. PE comatose with pinpoint pupils and rigid extended upper and lower extremities. On autopsy - intracranial hemorrhage where?
Pons
Intracerebral hemorrhage without an aneurysm is usually due to HTN. Talamus and putamen are most commonly affected
Pontine hemorrhage = pinpoint pupil, loss of horizontal gaze, quadriparesis, decerebrate posture, and rapid coma, death within hours
177
43 y/o man has worsening HA x 3 mo. Daily, worst at night. Dull, asoc with n/v. Recent visual changes. 170/96, bilateral papilledema and mass on MRI. Why does he have HAs?
Vasogenic edema
HA, n/v, papilledema = increased intracranial pressure often raised by neoplasms via: 1. disruption of BBB and 2. obstruction of CSF flow
Disruption of BBB = increased vascular permeability leading to vasogenic edema
blocking CSF circulation causes noncommunicating hydrocephalus which is not present in this pt
178
What skin changes can be seen in a pt with reactive arthritis?
keratoderma blennorrhagica
| Balantis circinata
179
What 2 types of epithelia are found in the cervix?
exocervix = stratified non-keratinized squamous epithelium
endocervix = simple columanr epithelium
Transformation zone - site of metaplasia where both cell types can be found (most sensitive to HPV)
Squamocoluman junction - squamous epithelim abruptly changes to columnar
180
4 y/o presents with Duschenne Muscular Dystrophy. This is caused by a defective or absent protein in which area of the muscle?
Cytoskeleton
| Connects the cytoskeleton of the muscle fiber to the surrounding ECM through the cell membrane
181
A GERD pt has epigastric cramping x 3 mo. Which lifestyle change can he make to reduce recurrence of his syx?
Decrease smoking
182
A 43 year old chronic alcoholic x10 years presents with jaundice after taking two extra-strength acetaminophen x 3days. Increased PT and AST. Alteration of which metabolite within hepatocytes caused this?
Decreased Glutathion
183
72 y/o Female has an MI with 90% narrowing of the artery supplying the diaphragmatic surface and aV node of the heart. She has left dominant circulatin. Which vessels must the catheter and balloon pass through to reach the narrowed vessel?
Left coronary, circumflex, posterior interventricular (posterior descending)
184
75 y/o male dies 1 week after a cerebral infarction. What type of necrosis?
Liquefaction
185
50 y/o woman presents with progressive SOB. She is treated with bosentan which antagonizes which mediator of pulmonary resistance?
Endothelin
186
Tx for insecticide poisoning?
Atropine
187
Do T2DMs tend to have high or low levels of endogenous insulin (esp during fasting)?
Low
188
A 39 y/o female presents with lots of syx that have never really been given a definitive dx. What should you do?
I'd like to assess the syx causing you the most distress and schedule montly follow ups
189
A pregnant woman at 25 weeks gestation reports using coccaine 2x/week. What is her baby at risk for?
Prematurity
190
2 month old presents with hypotonia and poor feeding since birth.
PE - large fontanels, midface hypoplasia, hepatomegaly, cryptorchidism
Serum - very long chain fatty acids, phytanic acid, and pipecolic acid
Pt most likely has absence of which organelle in his liver?
Peroxisomes
191
30 y/o nulligravid presents with inability to conceive. She has gained 80lbs since firsty trying to conceive and her LMP was 4 months ago. BMI = 35. She has a withdrawl bleed after a progestin challenge test. What is causing her oligomenorrhea?
Estrogen in the adipose tissue
192
A pt accidentally takes 4 tabs instread of 1 tab of his regular medication for angina pectoris and presents with general weakness
Drugs?
Reversible or irreversible?
Dose dependent or independent?
Nitroglycerin
| Reversible, dose-dependent
193
1 y/o presents with PKU. His phenylalanine hydroxylase gene is homozygous for a GT -> AT point mutation in intron 12 which causes skipping of exon 12. Explanation for exon skipping?
RNA splice error
194
A paper has a sample size to acheive 80% power of detecting a 15% mean difference with a significance level of 5%. If there is really no difference between the two groups, what is the chance that the study will find a statistically significant difference (albeit incorrect) and what type of error is this?
5%
| Type I
195
Formula for specificity
TN/(TN+FP) = specificity
196
Formula for sensitivity
TP/TP+FN = sensitivity
197
Firm thyroid nodules with sheets of granular cells embedded in a hyaline stroma. Presence of cytoplasmic calcitonin. Dx?
Medullary Thyroid cancer
| Arises from parafollicular cells (c cells)
198
75 y/o female has an enlargine lesion of the face x 3 months.
PE - brown-black, mottled, scaly lesion with irregular borders
Microscopy - atypical melanocytes spread along the basilar layer of the epidermia. Dx?
Lentigo maligna
199
Tx for Schizophrenia?
Olanzapine, Amuisulpried, risperidone, clozapine
200
13 y/o with leukemia has cells that express class I NHC and have rearrangement of the T cell receptor Beta chain D and J segments. What is the normal counterpark of these cells?
T lymphocyte thymocytes localized to the thymic cortex
201
Newborn undergoes surgical repair of esophageal atresia.
PE - esophagus is fibrotic and has no lumen. Which germ layer is the most likely origin of the cells that fill the lumen?
Endoderm
202
50 y.o man has SOB x 2 wks. Father had an MI at 52. Split S2 and hypokinesis of the posterior left ventricle during times of increased activity. Why?
Stenosis of the R coronary a.
203
21 y/o M is brought to the ED due to a self-inflicted laceration to his arm during an arrest. Hx of arrests for substance abuse, robbery, assault. His parents do not feel safe with him after he threatened his mom with a knife. Has not held jobs for any period of time but he is often fired for refusing to comply with policies. Dx?
Antisocial Personality Disorder
204
5 y/o is stung by a bee. There is edema within 30 minutes, extravascular accumulation of fluids due to?
Gap formation between endothelial cells
205
22 year old presents 30 min after his left forearm was slashed with a pocketknife. Pt has decreased over the palmer aspect of the thumb and index and middle fingers. What n. is damaged?
Median n.
206
Pt has decreased bone density on DEXA. What would be the expected changes in:
Osteoblast activity
Osteoclast actitivity
RANKL concentration
Decreased Osteoblast
Increase osteoclast
RANKL concentration increased
207
A UTI organism is resistant to ampicillin but sensitive to ceftriaxone. What is the mechanism of antibacterial resistance?
Beta-lactamase production
208
52 y/o man had sudden onset of blindness in the Left eye x 3 days. Fundoscopy reveals pale, opaque fundus and a bright red fovea centralis, dose scotoma of the entire visal field of the left eye. 6 months later the pt returns, still blind, what reaction would happen when light is show on the right eye?
No constriction because the retinal ganglion cells in the left eye have been destroyed
209
72 y/o F with diffuse muscle pain and weakness x 6 mo that is exacerbated by activity. Proximal muscle weakness and tenderness over the surface of both shins. High PTH, low Calcium. Dx?
Osteomalacia
210
69 y/o M with BPH has urinary retention one day after removal of a melanoma. After catherization a drug is administed that increases phophoinositide turnover in the smooth muscle cells of the bladder but has no effect on nicotinic synapses. What is the drug?
Bethanechol
211
Why is primaquine and chloroquine given to a pt with Plasmodium vivax?
Primaquine kills hynozoites
212
A 2 month old is not cyanotic but is brought in for VSD repair. What changes would be seen in:
LV pressure
RV pressure
LA pressure
LV pressure - increased
RV pressure - decreased
LA pressure - decreased
213
60 y/o F develops a secreting adenoma of the parathyroid gland. What is also likely to be decreased?
Calcium loss loss from bone
214
A pt starts HCTZ and presents with orthostatic hypotension. What changes would be seen in: venous return, Carotid sinus baroreceptor activity, cerebral blood flow when the pt stands?
Venous return - decreased
Carotid sinus baroreceptor activity - decreased
Cerebral blood flow - decreased
215
3 y/o has lead poisoning. Decreased activity of which enzyme is most likely?
Porphobilinogen synthase
| Porphoryn deficiency that is acquired through heavy metal poisoning.
216
Carcinoid syndrome is caused by an increase of?
Serotonin
217
Infant with SCID requires a blood transfusion for severe anemia. What blood product should he receive?
Irradiated packed red blood cells
218
A strain of H. pylori gains resistance. It's new isolates initially have the same sequence as the parent, but the later half is totally different. Which mechanism caused this?
Slipped-strand mispairing
219
In Graves dz, the syx are caused by hormones acting on which type of receptors?
Nuclear/retinoid X binding to DNA
220
Why doesn't ATP concentration really fall during a series of skeletal muscle twitches?
ATP is quickly regenerated from creatine phosphate
221
A breast cancer pt has 1 wk history of progressive loss of peripheral vision to the left in both eyes. Unable to count fingers or detect finger movements. She probably has a metastatic tumor where?
Occipital lobe
222
Pt presents with severe rectal pain, no bleeding. She is sexually active and uses condoms inconsistently. One PE big fat dark think protruding out of her anus. Dx?
External hemorrhoid
223
Pt presents with mildly depressed mood, decreased energy, and dry skin x 3 months. Thyroid gland is palapable but T4 is decreased. Dx?
Secondary hypothyroidism
224
At 30 weeks gestation a woman is admitted for contractions. U/s demonstrated that the fetal PDA has closed. Inhibition of which enzyme caused this finding?
Cyclooxygenase
Give indomethacin to close a PDA
Give prostaglandins to keep the PDA open
225
Following delivery, a woman delivers the placenta but continues to have heavy vaginal blood loss even though contractions have stopped. What medication would be helpful?
Oxytocin
226
Investigator wants to isolate a CD44 splice variant that correlates with dz progression (specifically over expression of one specific variant). Which method should he use?
Immunohistochemistry
227
Why can deoxygenated blood carry more CO2 for a given Pco2 than oxygenated blood?
Deoxyhemoglobin is a better buffer of hydrogen ions than oxyhemoglobin
228
What would be seen in a muscle contraction study following exposure to botulism??
end-plate potential
minature end plate potential
Response to ACh
End plate potential would be reduced but miniature end plate and response to ACh would be unchanged
229
how do you calculate loading dose?
Cp(Vd)/F
Cp = desired concentration
Vd = volume of distribution
230
How do you calculate ejection Fraction?
(end diastolic volume - end systolic volume)/ End diastolic volume
231
A newborn presents with narrow thorax, ears with periauricular skin tags, micrognathis, glossoptosis, mandibular cleft, and short palate, and respiratory distress. This is consistent with altered development of which pharyngeal arch?
First
232
What is the MOA of the antidote used in methanol poisoning?
Fomepizole, if unavailable use ethanol
Inhibits alcohol dehydrogenase, blocking the conversion of methanol to formaldehyde
Formaldehyde causes the blindness
233
What happens when a pt that is heterozygous for LDL receptor deficiency (familial hypercholesterolemia) takes a stating?
Increases LDL receptors
234
54 y/o M presents with a pancreatic mass that extends to the stomach and biliary system. What is he at risk of developing?
Major depressive disorder
235
22 year old has a history of intermittent jaundice associated with stress x 8 years. What is the underlying cause?
Decreased conjugation of bilirubin
236
3 year old has persistant diarrhea. Pt has marked lymphadenopathy that on bx demonstrate Mycobacterium avium. Pt has normal levels of IgA, IgG, IgM, B, T, and Cd4/8. Pt has a deficiency in?
IFN gamma receptor
237
What accounts for anesthetic to have a rapid onset of action?
Low blood solubility
238
Following the death of his sister 4 months ago, and 8 year old is still performing well in school. When asked about his sisters death, he cries and states he has a HA. Dx?
Normal emotional response
239
What would be expected in a PCOS pt for:
Fasting Insulin
Testosterone
LH
All increased
240
Recurrent infections + partial albinism + peripheral neuropathy
Chediak higashi syndrome
241
When a pt admits there is a problem but is not willing to do anything about it
Contemplation
242
When a pt is in complete denial that there is a problem
Pre-contemplation
243
MOA of niacin
Antagonize VDL cholesterol secretion
244
How do you increase lymph flow?
0.9% Saline.
| Increases capillary hydrostatic pressure
245
Cardiac septal defects + persistent truncus arteriosis is due to a defect in?
Neural crest migration
246
alpha 1 and beta blocker used in HTN?
Labetalol
247
Thrombosis of the SMA would be a problem for the?
Jejunum
248
PT with no hallucinations. Treated with gastric emptying and charcoal tx. Pupillary dilation. What did he take?
Amphetamines
249
Tx for jimsonweed toxicity?
Mimics atropine toxicity
Tx - Phyostigmine
Phyostigmine phixes atropine OD
250
Following calf immobilization muscle atrophies due to?
Polyubquination
251
Glucagon stimulates?
Glucose release from the liver
252
During choking, the vocal cords will be open or closed during:
Swallowing, laryngeal irritation, coughing
Closed during swallowing and laryngeal irritation
| Open during coughing
253
A baby is born to a woman with uncontrolled Graves dz. The baby has stridor, why?
TSH receptor binding Ab cross the placenta and induce goiter development -> Large thyroid gland
254
Cause of albinism?
Failure of melanin production. Normal melanocytes
255
Fxn of Ghrelin?
Stimulates hunger
256
Smokings effect on mucus, cilia activity, and macrophage fx?
Mucus production up
| Clicia activity, macrophage fxn down
257
Does a pulmonary embolism cause a shunt or dead space?
Dead space
258
Pedunculated mass in an adult heart? Presents with SOB on exertion
Myxoma
259
Sigmoid adenocarcinoma would drain into which lymph nodes?
Inferior mesenteric lymph nodes
260
Pt has a AAA and horseshoe kidney. The surgical approach to repaire the AAA would be complicated by?
Anomalous origins of multiple renal arteries to each kidney
261
8 year old girl presents with breast bud and a few pubic hairs. Whats going on?
This development is normal
262
Bx of a HCV liver demonstrates lymphocytic infiltration and collagen deposition. What is the inflammatory process?
Chronic inflammation
263
Pt presents with difficulty walking and loss of muscle mass. What is the process behind this?
Degeneration of motor neurons of the lumbar cord
| ALS or polio
264
Pt bing drinks and take acetaminophen. Increased liver injury due to?
Decreased acetaminophen clearance via glucuronidation
265
55 y/o asplenic pt has meningitis. Most likely organism?
Strep pneumo
266
Which strains of plasmodium have hypnozytes that are resistant to chloroquine?
P. vivax
| P. ovale
267
5 y/o boy presents with severe vomiting and sleepiness after taking aspirin for a flu-like illness. Why does he slip into a coma?
Cerebral Edema
| Reyes syndrome leads to hepatic encephalopathy
268
12 y/o boy presents with difficulty walking, lower extremity atrophy, and hammer toes. High stepping gait. What would be seen on bx?
Degeneration of oligodendrocytes
| Friedriech's ataxia
269
African American male presents with red bumps on his face and chin. Hyperpigmented papules over the cheeks, jawline, and neck. Dx?
Pseudofolliculitis barbae
| Shaving irritation
270
A baby is born without thyroid tissue but she had normal in utero development. Why?
Maternal transfer of T4 through the placenta
271
A pt is treated for a gastrinoma. What else should be included in her work up?
Serum calcium concentration
| Screen for MEN1 (Parathyroid tumors)
272
What structure is at risk of injury during removal of the ovary?
Ureter
273
Pt has seasonal allergies with nasal congestion, watery discharge, and sneezing. What would give him short term relief?
alpha-adrenergic agonist
| Vasoconstrict the vessels
274
Pt has a 1 yr hx of severe abdominal pain after meals, unintentional weight loss, and pain improves when she decreases how much she eats. Hx of atherosclerosis. PE abdominal bruit, diminished pedal pulses. This is all caused by stenosis of?
The superior mesenteric a.
275
Woman has a 3 weeks hx of left sided chest pain radiating to the back that is exacerbated when she reaches over her head or behind her back. Tenderness on palpation of the midline. CXR WNL. Dx?
Costochondritis
276
Older man presents with gouty tophi over the elbows and toes. He smokes, drinks distilled liquor, farms in central california, worked in a hat foactory, and worked in a textile factory. What caused his dz?
He has gout
| Related to drinking home-distilled liquor
277
Pt presents with a 2 weeks hx of hearing voices. Dx?
Brief psychotic disorder
278
Sickle cell pt is given penicillin as prophylaxis against?
S. pneumo
279
During anetshesia administration for an vertebral hernia, the posterior approach would penetrate which ligament?
Ligamentum flavum
| You pierce this before entering the arachnoid space
280
Pt has an uncal herniation due to aneurysm in which artery?
Ipsilateral posterior cerebral a.
281
If the sample size is decreased, what will happen to the confidence interval?
Increases in width
282
If placed on 100% nitrogen, which part of the kidney would be damaged first?
The proximal tubule
283
Pt has diabetes and HTN that is poorly controlled on HCTZ. What drug should be added
ACEI/ARB > CCB > Diuretics
| Look for a sartan
284
What lab changes are seen in menopause?
Increased FSH and LH
285
A pt is put on a morphine pump and presents days later with low respirations and pinpoint pupils. Why?
Morphine is metabolized to active metabolites that accumulate
286
Underlying mechanism of Li-Fraumeni syndrome?
defect in p53
Impaired regulation of apoptosis
Impaired cell cycle regulation (G1/S)
287
CF kid has numbness and tingling in her arms. Why?
Vitamin E deficiency
| Ataxia, peripheral neuropathy, retinopathy, impaired immune response
288
a pt with a strong hx of colon cancer wants to do a fecal occult test and no colonoscopy. Why should the physician refuse?
Low sensitivity
289
Kid has a recurrent URI's and developmental delay. Fibroblasts have inclusion bodies and deficienct in N-acetylglucosamine-1-phosphotransferase. Lots of acid hydrolases in the culture medium. Dx and enzymes are unable to target?
I-cell dz
Lysosomes
N-acetlyglucosamine-1-phosphotransferase in found in the Golid and tags lysosomal proteins with mannose-6-P so that they will be transported to the lysosome
290
In a radical prostatectomy, what structure has the greatest risk of injury?
Pudendal n. (pelvic parasympathetic n.)
